Method for preparation of printing plate by electrophotographic process and apparatus for use therein

Disclosed is a method for preparation of a printing plate by an electrophotographic process comprising forming a toner image on an electrophotographic light-sensitive element by an electrophotographic process. A peelable transfer layer is provided mainly containing a resin (A) capable of being removed upon a chemical reaction treatment on the toner image. The toner image is transferred together with the transfer layer onto a primary receptor. The toner image together with the transfer layer is then transferred from the primary receptor onto a receiving material having a surface which is capable of providing a hydrophilic surface suitable for lithographic printing at the time of printing. The transfer layer on the receiving material is removed by the chemical reaction treatment.

FIELD OF THE INVENTION 
The present invention relates to a method for preparation of a printing 
plate by an electrophotographic process, and more particularly to a method 
for preparation of a lithographic printing plate by an electrophotographic 
process including formation, transfer and removal of a transfer layer 
wherein the transfer layer is easily transferred and removed and good 
image qualities are maintained during a plate-making process thereby 
providing a printing plate which produces prints of good image qualities. 
BACKGROUND OF THE INVENTION 
Owing to the recent technical advancements of image processing by a 
computer, storage of a large amount of data and data communication, input 
of information, revision, edition, layout, and pagination are consistently 
computerized, and electronic editorial system enabling instantaneous 
output on a remote terminal plotter through a high speed communication 
network or a communications satellite has been practically used. 
Light-sensitive materials having high photo-sensitivity which may provide 
direct type printing plate precursors directly preparing printing plates 
based on the output from a terminal plotter include electrophotographic 
light-sensitive materials. 
In order to form a lithographic printing plate using an electrophotographic 
light-sensitive material, a method wherein after the formation of toner 
image by an electrophotographic process, non-image areas are subjected to 
oil-desensitization with an oil-desensitizing solution to obtain a 
lithographic printing plate, and a method wherein after the formation of 
toner image, a photoconductive layer is removed in non-image areas to 
obtain a lithographic printing plate are known. 
However, in these method, since the light-sensitive layer is subjected to 
treatment for rendering it hydrophilic to form hydrophilic non-image areas 
or removed by dissolving out it in the non-image areas to expose an 
underlying hydrophilic surface of support, there are various restrictions 
on the light-sensitive material, particularly a photoconductive compound 
and a binder resin employed in the photoconductive layer. Further, 
printing plates obtained have several problems on their image qualities or 
durability. 
In order to solve these problems there is proposed a method comprising 
providing a transfer layer composed of a thermoplastic resin capable of 
being removed upon a chemical reaction treatment on a surface of an 
electrophotographic light-sensitive element, forming a toner image on the 
transfer layer by a conventional electrophotographic process, transferring 
the toner image together with the transfer layer onto a receiving material 
capable of forming a hydrophilic surface suitable for a lithographic 
printing, and removing the transfer layer to leave the toner image on the 
receiving material whereby a lithographic printing plate is prepared as 
described in WO 93/16418. 
Since the method for preparation of printing plate using a transfer layer 
is different from the method for forming hydrophilic non-image areas by 
modification of the surface of light-sensitive layer or dissolution of the 
light-sensitive layer, and comprises the formation of toner image not on 
the light-sensitive layer but on the transfer layer, the transfer of toner 
image together with the transfer layer onto another support having a 
hydrophilic surface and the removal of the transfer layer by a chemical 
reaction treatment, printing plates-having good image qualities are 
obtained without various restrictions on the photoconductive layer 
employed as described above. 
However, in the above-described method, transferability of the transfer 
layer while applying heat and pressure is yet insufficient and thus, there 
are observed lack of fine images on the receiving material and the residue 
of toner image and transfer layer on the surface of light-sensitive 
element in some cases. In particular, a support having a hydrophilic 
surface to be used as the receiving material is restricted in order to 
obtain good transferability of transfer layer. Specifically, in case of 
employing a receiving material comprising a substrate having a surface of 
relatively poor smoothness, adhesion of the transfer layer to the 
receiving material is insufficient and as a result, transferability 
decreases. Further, the transfer layer must fulfill electrophotographic 
characteristics (Ep characteristics) in addition to the transferability 
and a dissolution property which is important in the step of preparing a 
printing plate, because on the transfer layer provided on a 
light-sensitive element are formed toner images by a conventional 
electrophotographic process. 
It is not easy to select a transfer layer which satisfies all of the 
transferability, dissolution property and electrophotographic 
characteristics. Accordingly, a resin to be employed in the transfer layer 
is imposed various restrictions on its basic structure such as polymer 
component and molecular weight. 
The electrophotographic characteristics, particularly, chargeability and 
dark decay (DQR) of transfer layer are greatly influenced by properties of 
resin used. In the event of poor electrophotographic characteristics, 
problems on image reproduction, for example, decrease in the maximum 
density of duplicated image and lack of fine lines and letters may tend to 
occur. Such a tendency becomes large when a thickness of the transfer 
layer is more than 5 .mu.m. To reduce the thickness of transfer layer, 
however, may result in degradation of transferability. Therefore, it is 
very difficult to satisfy both of the electrophotographic characteristics 
and the transferability. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a method for preparation 
of a lithographic printing plate using a transfer layer in which excellent 
transferability of the transfer layer is accomplished and good images are 
obtained without taking the electrophotographic characteristics of 
transfer layer into consideration. 
Another object of the present invention is to provide a method for 
preparation of a printing plate using a transfer layer which provides 
complete transfer of transfer layer and toner image irrespective of the 
kind of a receiving material. 
A still another object of the present invention is to provide a method for 
preparation of a printing plate using a transfer layer in which good 
transferability is maintained even when a thickness of transfer layer is 
reduced. 
A further object of the present invention is to provide a method for 
preparation of a printing plate using a transfer layer in which a latitude 
of transfer is enlarged and a desensitizing treatment is conducted under a 
mild condition. 
A still further object of the present invention is to provide an apparatus 
for preparation of a printing plate precursor which is suitable for use in 
the method for preparation of a printing plate described above. 
Other objects of the present invention will become apparent from the 
following description. 
It has been found that the above described objects of the present invention 
are accomplished by a method for preparation of a printing plate by an 
electrophotographic process comprising forming a toner image on an 
electrophotographic light-sensitive element by an electrophotographic 
process, providing a peelable transfer layer mainly containing a resin (A) 
capable of being removed upon a chemical reaction treatment on the toner 
image, transferring the toner image together with the transfer layer onto 
a primary receptor, transferring the toner image together with the 
transfer layer from the primary receptor onto a receiving material having 
a surface capable of providing a hydrophilic surface suitable for 
lithographic printing at the time of printing, and removing the transfer 
layer on the receiving material by the chemical reaction treatment.

DETAILED DESCRIPTION OF THE INVENTION 
The method for preparation of a printing plate by an electrophotographic 
process according to the present invention will be diagrammatically 
described with reference to FIG. 1 of the accompanying drawings. 
As shown in FIG. 1, the method for preparing a printing plate comprises 
forming a toner image 5 on an electrophotographic light-sensitive element 
11 having at least a support 1 and a light-sensitive layer 2 by a 
conventional electrophotographic process, providing a transfer layer 12 on 
the light-sensitive element 11 bearing the toner image 5, transferring the 
toner image 5 together with the transfer layer 12 onto a primary receptor 
20, further transferring the toner image 5 together with the transfer 
layer 12 onto a receiving material which is a support for an offset 
printing plate to prepare a printing plate precursor, and then removing 
the transfer layer 12 transferred onto the receiving material 30 by a 
chemical reaction treatment to prepare an offset printing plate. 
The method of the present invention is characterized by providing a 
transfer layer after the formation of toner image on a light-sensitive 
element by a conventional electrophotographic process as described above. 
Since a transfer layer is provided on a light-sensitive element before the 
formation of toner image by an electrophotographic process according to 
the known method for preparation of printing plate using a transfer layer, 
the transfer layer used must satisfy the requirement for forming good 
duplicated images without causing degradation of electrophotographic 
characteristics (such as chargeability, dark charge retention rate and 
photosensitivity). 
On the contrary, according to the present invention, there is no necessity 
for considering the electrophotographic characteristics of transfer layer 
described above, because the transfer layer is provided after the 
formation of toner image. Therefore, molecular design of resin to be used 
in the transfer layer can be conducted in order to fulfill the 
transferability and dissolution property without taking an electric 
insulating property into consideration. 
As a result, an enlarged latitude of transfer (for example, decrease in 
pressure and/or temperature for transfer, and increase in a transfer 
speed) and moderation of the condition of oil-desensitizing treatment can 
be achieved. 
The method of the present invention is also characterized by transferring 
once a toner image together with a transfer layer onto a primary receptor 
(intermediate medium) and then transferring the toner image together with 
the transfer layer onto a receiving material (hereinafter also referred to 
as a final receiving material sometimes). 
Since the transfer is performed through the primary receptor, 
transferability of transfer layer and toner image is improved based on an 
action of the intermediate medium as an elastomer (cushioning function). 
Specifically, the transferability is improved because a cushion effect due 
to the thickness of transfer layer per se is borne by the primary 
receptor. As a result, a condition for performing complete transfer can be 
determined even when various kinds of receiving materials are employed and 
the thickness of transfer layer can be reduced. 
Therefore, the toner image formed on a light-sensitive element is able to 
be transferred onto a final receiving material accompanying little or no 
degradation of image to produce a duplicated image of high accuracy and 
high quality. Further, the conditions for transfer and oil-desensitization 
can be moderated. 
The present invention also provides an apparatus for preparation of a 
printing plate precursor by an electrophotographic process comprising a 
means for forming a toner image on an electrophotographic light-sensitive 
element by an electrophotographic process, a means for providing a 
peelable transfer layer mainly containing a resin (A) capable of being 
released upon a chemical reaction treatment, a means for transferring the 
toner image together with the transfer layer onto a primary receptor, and 
a means for transferring the toner image together with the transfer layer 
from the primary receptor onto a receiving material, a surface of which is 
capable of providing a hydrophilic surface suitable for lithographic 
printing at the time of printing. 
Now, the electrophotographic light-sensitive element which can be used in 
the present invention will be described in detail below. 
Any conventionally known electrophotographic light-sensitive element can be 
employed. What is important is that the surface of light-sensitive element 
has the releasability at the time for the formation of toner image so as 
to easily release the toner image to be formed thereon together with a 
transfer layer. 
More specifically, an electrophotographic light-sensitive element wherein 
an adhesive strength of the surface thereof measured according to JIS Z 
0237-1980 "Testing methods of pressure sensitive adhesive tapes and 
sheets" is not more than 100 gram.multidot.force (g.multidot.f ) is 
preferably employed. 
The measurement of adhesive strength is conducted according to JIS Z 
0237-1980 8.3.1. 180 Degrees Peeling Method with the following 
modifications: 
(i) As a test plate, an electrophotographic light-sensitive element on 
which a toner image and a transfer layer are to be formed is used. 
(ii) As a test piece, a pressure resistive adhesive tape of 6 mm in width 
prepared according to JIS C2338-1984 is used. 
(iii) A peeling rate is 120 mm/min using a constant rate of traverse type 
tensile testing machine. 
Specifically, the test piece is laid its adhesive face downward on the test 
plate and a roller is reciprocate one stroke at a rate of approximately 
300 mm/min upon the test piece for pressure sticking. Within 20 to 40 
minutes after the sticking with pressure, a part of the stuck portion is 
peeled approximately 25 mm in length and then peeled continuously at the 
rate of 120 mm/min using the constant rate of traverse type tensile 
testing machine. The strength is read at an interval of approximately 20 
mm in length of peeling, and eventually read 4 times. The test is 
conducted on three test pieces. The mean value is determined from 12 
measured values for three test pieces and the resulting mean value is 
converted in terms of 10 mm in width. 
The measurement of adhesive strength of the surface of primary receptor or 
receiving material may also be conducted in the same manner as described 
above using the primary receptor or receiving material to be measured as 
the test plate. 
The adhesive strength of the surface of electrophotographic light-sensitive 
element is more preferably not more than 50 g.multidot.f, and particularly 
preferably not more than 30 g.multidot.f. 
Using such an electrophotographic light-sensitive element having the 
controlled adhesive strength, a toner image and a transfer layer formed on 
the light-sensitive element are easily and entirely transferred together 
onto a primary receptor. 
While an electrophotographic light-sensitive element which has already the 
surface exhibiting the desired releasability can be employed in the 
present invention, it is also possible to cause a compound (S) containing 
at least a fluorine atom and/or a silicon atom to adsorb or adhere onto 
the surface of electrophotographic light-sensitive element for imparting 
the releasability thereto before the formation of toner image. Thus, 
conventional electrophotographic light-sensitive elements can be utilized 
without taking releasability of the surface thereof into consideration. 
Further, when the releasability of the surface of electrophotographic 
light-sensitive element tends to decrease during repeated use of the 
light-sensitive element having the surface releasability according to the 
present invention, the method for adsorbing or adhering a compound (S) can 
be applied. By the method, the releasability of light-sensitive element is 
easily maintained. 
The impartation of releasability onto the surface of electrophotographic 
light-sensitive element is preferably carried out in an apparatus for 
preparation of a printing plate precursor, and specifically a means for 
causing the compound (S) to adsorb or adhere onto the surface of 
electrophotographic light-sensitive element is further provided in the 
apparatus for preparation of a printing plate precursor as described 
above. 
In order to obtain a light-sensitive element having a surface of the 
releasability, there are a method of selecting a light-sensitive element 
previously having such a surface of the releasability, and a method of 
imparting the releasability to a surface of electrophotographic 
light-sensitive element conventionally employed by causing the compound 
(S) for imparting releasability to adsorb or adhere onto the surface of 
light-sensitive element. 
Suitable examples of the light-sensitive elements previously having the 
surface of releasability used in the former method include those employing 
a photoconductive substance which is obtained by modifying a surface of 
amorphous silicon to exhibit the releasability. 
For the purpose of modifying the surface of electrophotographic 
light-sensitive element mainly containing amorphous silicon to have the 
releasability, there is a method of treating a surface of amorphous 
silicon with a coupling agent containing a fluorine atom and/or a silicon 
atom (for example, a silane coupling agent or a titanium coupling agent) 
as described, for example, in JP-A-55-89844, JP-A-4-231318, 
JP-A-60-170860, JP-A-59-102244 and JP-A-60-17750 (the term "JP-A" as used 
herein means an "unexamined published Japanese patent application"). Also, 
a method of adsorbing and fixing the compound (S) according to the present 
invention, particularly a releasing agent containing a component having a 
fluorine atom and/or a silicon atom as a substituent in the form of a 
block (for example, a polyether-, carboxylic acid-, amino group- or 
carbinol-modified polydialkylsilicone) as described in detail below can be 
employed. 
Further, another example of the light-sensitive elements previously having 
the surface of releasability is an electrophotographic light-sensitive 
element containing a polymer having a polymer component containing a 
fluorine atom and/or a silicon atom in the region near to the surface 
thereof. 
The term "region near to the surface of electrophotographic light-sensitive 
element" used herein means the uppermost layer of the light-sensitive 
element and includes an overcoat layer provided on a photoconductive layer 
and the uppermost photoconductive layer. Specifically, an overcoat layer 
is provided on the light-sensitive element having a photosensitive layer 
as the uppermost layer which contains the above-described polymer to 
impart the releasability, or the above-described polymer is incorporated 
into the uppermost layer of a photoconductive layer (including a single 
photoconductive layer and a laminated photoconductive layer) to modify the 
surface thereof so as to exhibit the releasability. 
In order to impart the releasability to the overcoat layer or the uppermost 
photoconductive layer, a polymer containing a silicon atom and/or a 
fluorine atom is used as a binder resin of the layer. It is preferred to 
use a small amount of a block copolymer containing a polymer segment 
comprising a silicon atom and/or fluorine atom-containing polymer 
component described in detail below (hereinafter referred to as a 
surface-localized type copolymer sometimes) in combination with other 
binder resins. Further, such polymers containing a silicon atom and/or a 
fluorine atom are employed in the form of grains. 
In the case of providing an overcoat layer, it is preferred to use the 
above-described surface-localized type block copolymer together with other 
binder resins of the layer for maintaining sufficient adhesion between the 
overcoat layer and the photoconductive layer. The surface-localized type 
copolymer is ordinarily used in a proportion of from 0.1 to 20 parts by 
weight per 100 parts by weight of the total composition of the overcoat 
layer. 
Specific examples of the overcoat layer include a protective layer which is 
a surface layer provided on the light-sensitive element for protection 
known as one means for ensuring durability of the surface of a 
light-sensitive element for a plain paper copier (PPC) using a dry toner 
against repeated use. For instance, techniques relating to a protective 
layer using a silicon type block copolymer are described, for example, in 
JP-A-61-95358, JP-A-55-83049, JP-A-62-87971, JP-A-61-189559, 
JP-A-62-75461, JP-A-62-139556, JP-A-62-139557, and JP-A-62-208055. 
Techniques relating to a protective layer using a fluorine type block 
copolymer are described, for example, in JP-A-61-116362, JP-A-61-117563, 
JP-A-61-270768, and JP-A-62-14657. Techniques relating to a protecting 
layer using grains of a resin containing a fluorine-containing polymer 
component in combination with a binder resin are described in 
JP-A-63-249152 and JP-A-63-221355. 
On the other hand, the method of modifying the surface of the uppermost 
photoconductive layer so as to exhibit the releasability is effectively 
applied to a so-called disperse type light-sensitive element which 
contains at least a photoconductive substance and a binder resin. 
Specifically, a layer constituting the uppermost layer of a photoconductive 
layer is made to contain either one or both of a block copolymer resin 
comprising a polymer segment containing a fluorine atom and/or silicon 
atom-containing polymer component as a block and resin grains containing a 
fluorine atom and/or silicon atom-containing polymer component, whereby 
the resin material migrates to the surface of the layer and is 
concentrated and localized there to have the surface imparted with the 
releasability. The copolymers and resin grains which can be used include 
those described in European Patent Application No. 534,479A1. 
In order to further ensure surface localization, a block copolymer 
comprising at least one fluorine atom and/or fluorine atom-containing 
polymer segment and at least one polymer segment containing a photo- 
and/or heat-curable group-containing component as blocks can be used as a 
binder resin for the overcoat layer or the photoconductive layer. Examples 
of such polymer segments containing a photo- and/or heat-curable 
group-containing component are described in European Patent Application 
No. 534,479A1. Alternatively, a photo- and/or heat-curable resin may be 
used in combination with the fluorine atom and/or silicon atom-containing 
resin in the present invention. 
The polymer comprising a polymer component containing a fluorine atom 
and/or a silicon atom effectively used for modifying the surface of the 
electrophotographic light-sensitive element according to the present 
invention include a resin (hereinafter referred to as resin (P) sometimes) 
and resin grains (hereinafter referred to as resin grains (PL) sometimes). 
Where the polymer containing a fluorine atom and/or silicon atom-containing 
polymer component used in the present invention is a random copolymer, the 
content of the fluorine atom and/or silicon atom-containing polymer 
component is preferably at least 60% by weight, and more preferably at 
least 80% by weight based on the total polymer component. 
In a preferred embodiment, the above-described polymer is a block copolymer 
comprising at least one polymer segment (.alpha.) containing at least 50% 
by weight of a fluorine atom and/or silicon atom-containing polymer 
component and at least one polymer segment (.beta.) containing 0 to 20% by 
weight of a fluorine atom and/or silicon atom-containing polymer 
component, the polymer segments (.alpha.) and (.beta.) being bonded in the 
form of blocks. More preferably, the polymer segment (.beta.) of the block 
copolymer contains at least one polymer component containing at least one 
photo- and/or heat-curable functional group. 
It is preferred that the polymer segment (.beta.) does not contain any 
fluorine atom and/or silicon atom-containing polymer component. 
As compared with the random copolymer, the block copolymer comprising the 
polymer segments (.alpha.) and (.beta.) (surface-localized type copolymer) 
is more effective not only for improving the surface releasability but 
also for maintaining such releasability. 
More specifically, where a film is formed in the presence of a small amount 
of the resin or resin grains of copolymer containing a fluorine atom 
and/or a silicon atom, the resins (P) or resin grains (PL) easily migrate 
to the surface portion of the film and are localized in situ by the end of 
a drying step of the film to thereby modify the film surface so as to 
exhibit the releasability. 
Where the resin (P) is the block copolymer in which the fluorine atom 
and/or silicon atom-containing polymer segment (.alpha.) exists as a 
block, the other polymer segment (.beta.) containing no, or if any a small 
proportion of, fluorine atom and/or silicon atom-containing polymer 
component undertakes sufficient interaction with the film-forming binder 
resin since it has good compatibility therewith. Thus, during the 
formation of a toner image or a transfer layer on the light-sensitive 
element, further migration of the resin into the toner image or transfer 
layer is inhibited or prevented by an anchor effect to form and maintain 
the definite interface between the toner image or transfer layer and the 
photoconductive layer. 
Further, where the segment (.beta.) of the block copolymer contains a 
photo- and/or heat-curable group, crosslinking between the polymer 
molecules takes place during the film formation to thereby ensure 
retention of the releasability at the interface of the light-sensitive 
element. 
The above-described polymer may be used in the form of resin grains as 
described above. Preferred resin grains (PL) are resin grains dispersible 
in a non-aqueous solvent. Such resin grains include a block copolymer 
comprising a non-aqueous solvent-insoluble polymer segment (.alpha.) which 
contains a fluorine atom and/or silicon atom-containing polymer component 
and a non-aqueous solvent-soluble polymer segment (.beta.) which contains 
no, or if any not more than 20% of, fluorine atom and/or silicon 
atom-containing polymer component. 
Where the resin grains according to the present invention are used in 
combination with a binder resin, the insolubilized polymer segment 
(.alpha.) undertakes migration of the grains to the surface portion and is 
localized in situ while the soluble polymer segment (.beta.) exerts an 
interaction with the binder resin (an anchor effect) similarly to the 
above-described resin. When the resin grains contain a photo- and/or 
heat-curable group, further migration of the grains to the toner image or 
transfer layer can be avoided. 
The moiety having a fluorine atom and/or a silicon atom contained in the 
resin (P) or resin grains (PL) includes that incorporated into the main 
chain of the polymer and that contained as a substituent in the side chain 
of the polymer. 
The fluorine atom-containing moieties include monovalent or divalent 
organic residues, for example, -C.sub.h F.sub.2h+1 (wherein h represents 
an integer of from 1 to 22), -(CF.sub.2).sub.j CF.sub.2 H (wherein j 
represents an integer of from 1 to 17), -CFH.sub.2, 
##STR1## 
(wherein l represents an integer of from 1 to 5), -CF.sub.2 -, -CFH-, 
##STR2## 
(wherein k represents an integer of from 1 to 4). 
The silicon atom-containing moieties include monovalent or divalent organic 
residues, for example, 
##STR3## 
wherein R.sup.31, R.sup.32, R.sup.33, R.sup.34, and R.sup.35, which may be 
the same or different, each represents a hydrocarbon group which may be 
substituted or -OR.sup.36 wherein R.sup.36 represents a hydrocarbon group 
which may be substituted. 
The hydrocarbon group represented by R.sup.31, R.sup.32, R.sup.33, 
R.sup.34, R.sup.35 or R.sup.36 include specifically an alkyl group having 
from 1 to 18 carbon atoms which may be substituted (e.g., methyl, ethyl, 
propyl, butyl, hexyl, octyl, decyl, dodecyl, hexadecyl, 2-chloroethyl, 
2-bromoethyl, 2,2,2-trifluoroethyl, 2-cyanoethyl, 3,3,3-trifluoropropyl, 
2-methoxyethyl, 3-bromopropyl, 2-methoxycarbonylethyl, or 
2,2,2,2',2',2'-hexafluoroisopropyl), an alkenyl group having from 4 to 18 
carbon atoms which may be substituted (e.g., 2-methyl-1-propenyl, 
2-butenyl, 2-pentenyl, 3-methyl-2-pentenyl, 1-pentenyl, 1-hexenyl, 
2-hexenyl, or 4-methyl-2-hexenyl), an aralkyl group having from 7 to 12 
carbon atoms which may be substituted (e.g., benzyl, phenethyl, 
3-phenylpropyl, naphthylmethyl, 2-naphthylethyl, chlorobenzyl, 
bromobenzyl, methylbenzyl, ethylbenzyl, methoxybenzyl, dimethylbenzyl, or 
dimethoxybenzyl), an alicyclic group having from 5 to 8 carbon atoms which 
may be substituted (e.g., cyclohexyl, 2-cyclohexylethyl, or 
2-cyclopentylethyl), or an aromatic group having from 6 to 12 carbon atoms 
which may be substituted (e.g., phenyl, naphthyl, tolyl, xylyl, 
propylphenyl, butylphenyl, octylphenyl, dodecylphenyl, methoxyphenyl, 
ethoxyphenyl, butoxyphenyl, decyloxyphenyl, chlorophenyl, dichlorophenyl, 
bromophenyl, cyanophenyl, acetylphenyl, methoxycarbonylphenyl, 
ethoxycarbonylphenyl, butoxycarbonylphenyl, acetamidophenyl, 
propionamidophenyl, or dodecyloylamidophenyl). 
The fluorine atom and/or silicon atom-containing organic residue may be 
composed of a combination thereof. In such a case, they may be combined 
either directly or via a linking group. The linking groups include 
divalent organic residues, for example, divalent aliphatic groups, 
divalent aromatic groups, and combinations thereof, which may or may not 
contain a bonding group, e.g., 
##STR4## 
wherein d.sup.1 has the same meaning as R.sup.31 above. 
Examples of the divalent aliphatic groups are shown below. 
##STR5## 
wherein e.sup.1 and e.sup.2, which may be the same or different, each 
represents a hydrogen atom, a halogen atom (e.g., chlorine or bromine) or 
an alkyl group having from 1 to 12 carbon atoms (e.g., methyl, ethyl, 
propyl, chloromethyl, bromomethyl, butyl, hexyl, octyl, nonyl or decyl); 
and Q represents 
##STR6## 
wherein d.sup.2 represents an alkyl group having from 1 to 4 carbon atoms, 
-CH.sub.2 Cl, or -CH.sub.2 Br. 
Examples of the divalent aromatic groups include a benzene ring, a 
naphthalene ring, and a 5- or 6-membered heterocyclic ring having at least 
one hereto atom selected from an oxygen atom, a sulfur atom and a nitrogen 
atom. The aromatic groups may have a substituent, for example, a halogen 
atom (e.g., fluorine, chlorine or bromine), an alkyl group having from 1 
to 8 carbon atoms (e.g., methyl, ethyl, propyl, butyl, hexyl or octyl) or 
an alkoxy group having from 1 to 6 carbon atoms (e.g., methoxy, ethoxy, 
propoxy or butoxy). Examples of the heterocyclic ring include a furan 
ring, a thiophene ring, a pyridine ring, a piperazine ring, a 
tetrahydrofuran ring, a pyrrole ring, a tetrahydropyran ring, and a 
1,3-oxazoline ring. 
Specific examples of the repeating units having the fluorine atom and/or 
silicon atom-containing moiety as described above are set forth below, but 
the present invention should not be construed as being limited thereto. In 
formulae (F-1) to (F-32) below, R.sub.f represents any one of the 
following groups of from (1) to (11); and b represents a hydrogen atom or 
a methyl group. 
##STR7## 
wherein R.sub.f' represents any one of the above-described groups of from 
(1) to (8); n represents an integer of from 1 to 18; m represents an 
integer of from 1 to 18; and l represents an integer of from 1 to 5. 
##STR8## 
Of the resins (P) and resin grains (PL) each containing silicon atom and/or 
fluorine atom used in the present invention, the so-called 
surface-localized type copolymers will be described in detail below. 
The content of the silicon atom and/or fluorine atom-containing polymer 
component in the segment (.alpha.) is at least 50% by weight, preferably 
at least 70% by weight, and more preferably at least 80% by weight. The 
content of the fluorine atom and/or silicon atom-containing polymer 
component in the segment (.beta.) is not more than 20% by weight, and 
preferably 0% by weight. 
A weight ratio of segment (.alpha.):segment (.beta.) ranges usually from 
1:99 to 95:5, and preferably from 5:95 to 90:10. In the range described 
above, the good migration effect and anchor effect of the resin (P) or 
resin grain (PL) at the surface region of light-sensitive element are 
obtained. 
The resin (P) preferably has a weight average molecular weight of from 
5.times.10.sup.3 to 1.times.10.sup.6, and more preferably from 
1.times.10.sup.4 to 5.times.10.sup.5. The segment (.alpha.) in the resin 
(P) preferably has a weight average molecular weight of at least 
1.times.10.sup.3. 
The resin grain (PL) preferably has an average grain diameter of from 0.001 
to 1 .mu.m, and more preferably from 0.05 to 0.5 .mu.m. 
A preferred embodiment of the surface-localized type copolymer in the resin 
(P) according to the present invention will be described below. Any type 
of the block copolymer can be used as far as the fluorine atom and/or 
silicon atom-containing polymer component is contained as a block. The 
term "to be contained as a block" means that the polymer has the polymer 
segment (.alpha.) containing at least 50% by weight of the fluorine atom 
and/or silicon atom-containing polymer component. The forms of blocks 
include an A-B type block, an A-B-A type block, a B-A-B type block, a 
graft type block, and a starlike type block as schematically illustrated 
below. 
##STR9## 
These various types of block copolymers (P) can be synthesized in 
accordance with conventionally known polymerizing methods. Useful methods 
are described, e.g., in W. J. Burlant and A. S. Hoffman, Block and Graft 
Polymers, Reuhold (1986), R. J. Cevesa, Block and Graft Copolymers, 
Butterworths (1962), D. C. Allport and W. H. James, Block Copolymers, 
Applied Sci. (1972), A. Noshay and J. E. McGrath, Block Copolymers, 
Academic Press (1977), G. Huvtreg, D. J. Wilson, and G. Riess, NATO 
ASIser. SerE., Vol. 1985, p. 149, and V. Perces, Applied Polymer Sci., 
Vol. 285, p. 95 (1985). 
For example, ion polymerization reactions using an organometallic compound 
(e.g., an alkyl lithium, lithium diisopropylamide, an alkali metal 
alcoholate, an alkylmagnesium halide, or an alkylaluminum halide) as a 
polymerization initiator are described, for example, in T. E. Hogeu-Esch 
and J. Smid, Recent Advances in Anion Polymerization, Elsevier (New York) 
(1987), Yoshio Okamoto, Kobunshi, Vol. 38, P. 912 (1989), Mitsuo Sawamoto, 
Kobunshi, Vol. 38, p. 1018 (1989), Tadashi Narita, Kobunshi, Vol. 37, p. 
252 (1988), B. C. Anderson, et al., Macromolecules, Vol. 14, p. 1601 
(1981), and S. Aoshima and T. Higasimura, Macromolecules, Vol. 22, p. 1009 
(1989). 
Ion polymerization reactions using a hydrogen iodide/iodine system are 
described, for example, in T. Higashimura, et al., Macromol. Chem., 
Macromol. Symp., Vol. 13/14, p. 457 (1988), and Toshinobu Higashimura and 
Mitsuo Sawamoto, Kobunshi Ronbunshu, Vol. 46, p. 189 (1989). 
Group transfer polymerization reactions are described, for example, in D. 
Y. Sogah, et al., Macromolecules, Vol. 20, p. 1473 (1987), O. W. Webster 
and D. Y. Sogah, Kobunshi, Vol. 36, p. 808 (1987), M. T. Reetg, et al., 
Angew. Chem. Int. Ed. Engl., Vol. 25, p. 9108 (1986), and JP-A-63-97609. 
Living polymerization reactions using a metalloporphyrin complex are 
described, for example, in T. Yasuda, T. Aida, and S. Inoue, 
Macromolecules, Vol. 17, p. 2217 (1984), M. Kuroki, T. Aida, and S. Inoue, 
J. Am. Chem. Soc., Vol. 109, p. 4737 (1987), M. Kuroki, et al., 
Macromolecules, Vol. 21, p. 3115 (1988), and M. Kuroki and I. Inoue, Yuki 
Gosei Kagaku, Vol. 47, p. 1017 (1989). 
Ring-opening polymerization reactions of cyclic compounds are described, 
for example, in S. Kobayashi and T. Saegusa, Ring Opening Polymerization, 
Applied Science Publishers Ltd. (1984), W. Seeliger, et al., Angew. Chem. 
Int. Ed. Engl., Vol. 5, p. 875 (1966), S. Kobayashi, et al., Poly. Bull., 
Vol. 13, p. 447 (1985), and Y. Chujo, et al., Macromolecules, Vol. 22, p. 
1074 (1989). 
Photo living polymerization reactions using a dithiocarbamate compound or a 
xanthate compound, as an initiator are described, for example, in Takayuki 
Otsu, Kobunshi, Vol. 37, p. 248 (1988), Shun-ichi Himori and Koichi Otsu, 
Polymer Rep. Jap., Vol. 37, p. 3508 (1988), JP-A-64-111, JP-A-64-26619, 
and M. Niwa, Macromolecules, Vol. 189, p. 2187 (1988). 
Radical polymerization reactions using a polymer containing an azo group or 
a peroxide group as an initiator to synthesize block copolymers are 
described, for example, in Akira Ueda, et al., Kobunshi Ronbunshu, Vol. 
33, p. 931 (1976), Akira Ueda, Osaka Shiritsu Kogyo Kenkyusho Hokoku, Vol. 
84 (1989), O. Nuyken, et al., Macromol. Chem., Rapid. Commun., Vol. 9, p. 
671 (1988), and Ryohei Oda, Kagaku to Kogyo, Vol. 61, p. 43 (1987). 
Syntheses of graft type block copolymers are described in the above-cited 
literature references and, in addition, Fumio Ide, Graft Jugo to Sono Oyo, 
Kobunshi Kankokai (1977), and Kobunshi Gakkai (ed.), Polymer Alloy, Tokyo 
Kagaku Dojin (1981). For example, known grafting techniques including a 
method of grafting of a polymer chain by a polymerization initiator, an 
actinic ray (e.g., radiant ray, electron beam), or a mechanochemical 
reaction; a method of grafting with chemical bonding between functional 
groups of polymer chains (reaction between polymers); and a method of 
grafting comprising a polymerization reaction of a macromonomer may be 
employed. 
The methods of grafting using a polymer are described, for example, in T. 
Shiota, et al., J. Appl. Polym. Sci., Vol. 13, p. 2447 (1969), W. H. Buck, 
Rubber Chemistry and Technology, Vol. 50, p. 109 (1976), Tsuyoshi Endo and 
Tsutomu Uezawa, Nippon Secchaku Kyokaishi, Vol. 24, p. 323 (1988), and 
Tsuyoshi Endo, ibid., Vol. 25, p. 409 (1989). 
The methods of grafting using a macromonomer are described, for example, in 
P. Dreyfuss and R. P. Quirk, Encycl. Polym. Sci. Eng., Vol. 7, p. 551 
(1987), P. F. Rempp and E. Franta, Adv. Polym. Sci., Vol. 58, p. 1 (1984), 
V. Percec, Appl. Poly. Sci., Vol. 285, p. 95 (1984), R. Asami and M. 
Takari, Macromol. Chem. Suppl., Vol. 12, p. 163 (1985), P. Rempp, et al., 
Macromol. Chem. Suppl., Vol. 8, p. 3 (1985), Katsusuke Kawakami, Kagaku 
Kogyo, Vol. 38, p. 56 (1987), Yuya Yamashita, Kobunshi, Vol. 31, p. 988 
(1982), Shiro Kobayashi, Kobunshi, Vol. 30, p. 625 (1981), Toshinobu 
Higashimura, Nippon Secchaku Kyokaishi, Vol. 18, p. 536 (1982), Koichi 
Itoh, Kobunshi Kako, Vol. 35, p. 262 (1986), Takashiro Azuma and Takashi 
Tsuda, Kino Zairyo, Vol. 1987, .No. 10, p. 5, Yuya Yamashita (ed.), 
Macromonomer no Kagaku to Kogyo, I.P.C. (1989), Tsuyoshi Endo (ed.), 
Atarashii Kinosei Kobunshi no Bunshi Sekkei, Ch. 4, C.M.C. (1991), and Y. 
Yamashita, et al., Polym. Bull., Vol. 5, p. 361 (1981). 
Syntheses of starlike block copolymers are described, for example, in M. T. 
Reetz, Angew. Chem. Int. Ed. Engl., Vol. 27, p. 1373 (1988), M. Sgwarc, 
Carbanions, Living Polymers and Electron Transfer Processes, Wiley (New 
York) (1968), B. Gordon, et al., Polym. Bull., Vol. 11, p. 349 (1984), R. 
B. Bates, et al., J. Org. Chem., Vol. 44, p. 3800 (1979), Y. Sogah, A.C.S. 
Polym. Rapr., Vol. 1988, No. 2, p. 3, J. W. Mays, Polym. Bull., Vol. 23, 
p. 247 (1990), I. M. Khan et al., Macromolecules, Vol. 21, p. 2684 (1988), 
A. Morikawa, Macromolecules, Vol. 24, p. 3469 (1991), Akira Ueda and Toru 
Nagai, Kobunshi, Vol. 39, p. 202 (1990), and T. Otsu, Polymer Bull., Vol. 
11, p. 135 (1984). 
While reference can be made to known techniques described in the 
literatures cited above, the method for synthesizing the block copolymers 
(P) according to the present invention is not limited to these methods. 
A preferred embodiment of the resin grains (PL) according to the present 
invention will be described below. As described above, the resin grains 
(PL) preferably comprises the fluorine atom and/or silicon atom-containing 
polymer segment (.alpha.) insoluble in a non-aqueous solvent and the 
polymer segment (.beta.) which is soluble in a non-aqueous solvent and 
contains substantially no fluorine atom and/or silicon atom. The polymer 
segment (.alpha.) constituting the insoluble portion of the resin grain 
(PL) may have a crosslinked structure. 
Preferred methods for synthesizing the resin grains (PL) include the 
non-aqueous dispersion polymerization method described hereinafter with 
respect to non-aqueous solvent-dispersed resin grains. 
The non-aqueous solvents which can be used in the preparation of the 
non-aqueous solvent-dispersed resin grains include any organic solvents 
having a boiling point of not more than 200.degree. C., either 
individually or in combination of two or more thereof. Specific examples 
of such organic solvents include alcohols such as methanol, ethanol, 
propanol, butanol, fluorinated alcohols and benzyl alcohol, ketones such 
as acetone, methyl ethyl ketone, cyclohexanone and diethyl ketone, ethers 
such as diethyl ether, tetrahydrofuran and dioxane, carboxylic acid esters 
such as methyl acetate, ethyl acetate, butyl acetate and methyl 
propionate, aliphatic hydrocarbons containing from 6 to 14 carbon atoms 
such as hexane, octane, decane, dodecane, tridecane, cyclohexane and 
cyclooctane, aromatic hydrocarbons such as benzene, toluene, xylene and 
chlorobenzene, and halogenated hydrocarbons such as methylene chloride, 
dichloroethane, tetrachloroethane, chloroform, methylchloroform, 
dichloropropane and trichloroethane. However, the present invention should 
not be construed as being limited thereto. 
Dispersion polymerization in such a non-aqueous solvent system easily 
results in the production of monodispersed resin grains having an average 
grain diameter of not greater than 1 .mu.m with a very narrow size 
distribution. 
More specifically, a monomer corresponding to the polymer component 
constituting the segment (.alpha.) (hereinafter referred to as a monomer 
(a)) and a monomer corresponding to the polymer component constituting the 
segment (.beta.) (hereinafter referred to as a monomer ,(b)) are 
polymerized by heating in a non-aqueous solvent capable of dissolving a 
monomer (a) but incapable of dissolving the resulting polymer in the 
presence of a polymerization initiator, for example, a peroxide (e.g., 
benzoyl peroxide or lauroyl peroxide), an azobis compound (e.g., 
azobisisobutyronitrile or azobisisovaleronitrile), or an organometallic 
compound (e.g., butyl lithium). Alternatively, a monomer (a) and a polymer 
comprising the segment (.beta.) (hereinafter referred to as a polymer 
(P.beta.)) are polymerized in the same manner as described above. 
The inside of the polymer grain (PL) according to the present invention may 
have a crosslinked structure. The formation of crosslinked structure can 
be conducted by any of conventionally known techniques. For example, (i) a 
method wherein a polymer containing the polymer segment (.alpha.) is 
crosslinked in the presence of a crosslinking agent or a curing agent; 
(ii) a method wherein at least the monomer (a) corresponding to the 
polymer segment (.alpha.) is polymerized in the presence of a 
polyfunctional monomer or oligomer containing at least two polymerizable 
functional groups to form a network structure over molecules; or (iii) a 
method wherein the polymer segment (.alpha.) and a polymer containing a 
reactive group-containing polymer component are subjected to a 
polymerization reaction or a polymer reaction to cause crosslinking may be 
employed. 
The crosslinking agents to be used in the method (i) include those commonly 
employed as described, e.g., in Shinzo Yamashita and Tosuke Kaneko (ed.), 
Kakyozai Handbook, Taiseisha (1981) and Kobunshi Gakkai (ed.), Kobunshi 
Data Handbook (Kiso-hen), Baifukan (1986). 
Specific examples of suitable crosslinking agents include organosilane 
compounds known as silane coupling agents (e.g., vinyltrimethoxysilane, 
vinyltributoxysilane, .gamma.-glycidoxypropyltrimethoxysilane, 
.gamma.-mercaptopropyltriethoxysilane, and 
.gamma.-aminopropyltriethoxysilane), polyisocyanate compounds (e.g., 
toluylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane 
triisocyanate, polymethylenepolyphenyl isocyanate, hexamethylene 
diisocyanate, isophorone diisocyanate, and polymeric polyisocyanates), 
polyol compounds (e.g., 1,4-butanediol, polyoxypropylene glycol, 
polyoxyethylene glycols, and 1,1,1-trimethylolpropane), polyamine 
compounds (e.g., ethylenediamine, .gamma.-hydroxypropylated 
ethylenediamine, phenylenediamine, hexamethylenediamine, 
N-aminoethylpiperazine, and modified aliphatic polyamines), titanate 
coupling compounds (e.g., titanium tetrabutoxide, titanium tetrapropoxide, 
and isopropyltrisstearoyl titanate), aluminum coupling compounds (e.g., 
aluminum butylate, aluminum acetylacetate, aluminum oxide octate, and 
aluminum trisacetylacetate), polyepoxy group-containing compounds and 
epoxy resins (e.g., the compounds as described in Hiroshi Kakiuchi (ed.), 
Shin-Epoxy Jushi, Shokodo (1985) and Kuniyuki Hashimoto (ed.), Epoxy 
Jushi, Nikkan Kogyo Shinbunsha (1969)), melamine resins (e.g., the 
compounds as described in Ichiro Miwa and Hideo Matsunaga (ed.), 
Urea.multidot.Melamine Jushi, Nikkan Kogyo Shinbunsha (1969)), and 
poly(meth)acrylate compounds (e.g., the compounds as described in Shin 
Okawara, Takeo Saegusa, and Toshinobu Higashimura (ed.), Oligomer, 
Kodansha (1976), and Eizo Omori, Kinosei Acryl-kei Jushi, Techno System 
(1985)). 
Specific examples of the polymerizable functional groups which are 
contained in the polyfunctional monomer or oligomer (the monomer will 
sometimes be referred to as a polyfunctional monomer (d)) having two or 
more polymerizable functional groups used in the method (ii) above include 
CH.sub.2 .dbd.CH-CH.sub.2 -, CH.sub.2 .dbd.CH-CO-O-, CH.sub.2 .dbd.CH-, 
CH.sub.2 .dbd.C(CH.sub.3)-CO-O-, CH(CH.sub.3).dbd.CH-CO-O-, CH.sub.2 
.dbd.CH-CONH-, CH.sub.2 .dbd.C(CH.sub.3)-CONH-, CH(CH.sub.3).dbd.CH-CONH-, 
CH.sub.2 .dbd.CH-O -CO-, CH.sub.2 .dbd.C(CH.sub.3)-O-CO-, CH.sub.2 
.dbd.CH-CH.sub.2 -O-CO-, CH.sub.2 .dbd.CH-NHCO-, CH.sub.2 .dbd.CH-CH.sub.2 
-NHCO-, CH.sub.2 .dbd.CH-SO.sub.2 -, CH.sub.2 .dbd.CH-CO-, CH.sub.2 
.dbd.CH-O-, and CH.sub.2 .dbd.CH-S-. The two or more polymerizable 
functional groups present in the polyfunctional monomer or oligomer may be 
the same or different. 
Specific examples of the monomer or oligomer having the same two or more 
polymerizable functional groups include styrene derivatives (e.g., 
divinylbenzene and trivinylbenzene); methacrylic, acrylic or crotonic acid 
esters, vinyl ethers, or allyl ethers of polyhydric alcohols (e.g., 
ethylene glycol, diethylene glycol, triethylene glycol, polyethylene 
glycol 200, 400 or 600, 1,3-butylene glycol, neopentyl glycol, dipropylene 
glycol, polypropylene glycol, trimethylolpropane, trimethylolethane, and 
pentaerythritol) or polyhydric phenols (e.g., hydroquinone, resorcin, 
catechol, and derivatives thereof); vinyl esters, allyl esters, vinyl 
amides, or allyl amides of dibasic acids (e.g., malonic acid, succinic 
acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic 
acid, and itaconic acid); and condensation products of polyamines (e.g., 
ethylenediamine, 1,3-propylenediamine, and 1,4-butylenediamine) and 
vinyl-containing carboxylic acids (e.g., methacrylic acid, acrylic acid, 
crotonic acid, and allylacetic acid). 
Specific examples of the monomer or oligomer having two or more different 
polymerizable functional groups include reaction products between vinyl 
group-containing carboxylic acids (e.g., methacrylic acid, acrylic acid, 
methacryloylacetic acid, acryloylacetic acid, methacryloylpropionic acid, 
acryloylpropionic acid, itaconyloylacetic acid, itaconyloylpropionic acid, 
and a carboxylic acid anhydride) and alcohols or amines, vinyl 
group-containing ester derivatives or amide derivatives (e.g., vinyl 
methacrylate, vinyl acrylate, vinyl itaconate, allyl methacrylate, allyl 
acrylate, allyl itaconate, vinyl methacryloylacetate, vinyl 
methacryloylpropionate, allyl methacryloylpropionate, 
vinyloxycarbonylmethyl methacrylate, 
vinyloxycarbonylmethyloxycarbonylethylene acrylate, N-allylacrylamide, 
N-allylmethacrylamide, N-allylitaconamide, and methacryloylpropionic acid 
allylamide) and condensation products between amino alcohols (e.g., 
aminoethanol, 1-aminopropanol, 1-aminobutanol, 1-aminohexanol, and 
2-aminobutanol) and vinyl group-containing carboxylic acids. 
The monomer or oligomer containing two or more polymerizable functional 
groups is used in an amount of not more than 10 mol %, and preferably not 
more than 5 mol %, based on the total amount of monomer (a) and other 
monomers copolymerizable with monomer (a) to form the resin. 
Where crosslinking between polymer molecules is conducted by the formation 
of chemical bonds upon the reaction of reactive groups in the polymers 
according to the method (iii), the reaction may be effected in the same 
manner as usual reactions of organic low-molecular weight compounds. 
From the standpoint of obtaining mono-dispersed resin grains having a 
narrow size distribution and easily obtaining fine resin grains having a 
diameter of 0.5 .mu.m or smaller, the method (ii) using a poly-functional 
monomer is preferred for the formation of network structure. Specifically, 
a monomer (a), a monomer (b) and/or a polymer (P.beta.) and, in addition, 
a polyfunctional monomer (d) are subjected to polymerization granulation 
reaction to obtain resin grains. Where the above-described polymer 
(P.beta.) comprising the segment (.beta.) is used, it is preferable to use 
a polymer (P.beta.') which has a polymerizable double bond group 
copolymerizable with the monomer (a) in the side chain or at one terminal 
of the main chain of the polymer (P.beta.). 
The polymerizable double bond group is not particularly limited as far as 
it is copolymerizable with the monomer (a). Specific examples thereof 
include 
##STR10## 
(wherein n represents 0 or an integer of from 1 to 3), CH.sub.2 .dbd.CHO-, 
and CH.sub.2 .dbd.CH-C.sub.6 H.sub.4 -, wherein p represents -H or 
-CH.sub.3. 
The polymerizable double bond group may be bonded to the polymer chain 
either directly or via a divalent organic residue. Specific examples of 
these polymers include those described, for example, in JP-A-61-43757, 
JP-A-1-257969, JP-A-2-74956, JP-A-1-282566, JP-A-2-173667, JP-A-3-15862, 
and JP-A-4-70669. 
In the preparation of resin grains, the total amount of the polymerizable 
compounds used is from about 5 to about 80 parts by weight, preferably 
from 10 to 50 parts by weight, per 100 parts by weight of the non-aqueous 
solvent. The polymerization initiator is usually used in an amount of from 
0.1 to 5% by weight based on the total amount of the polymerizable 
compounds. The polymerization is carried out at a temperature of from 
about 30.degree. to about 180.degree. C., and preferably from 40.degree. 
to 120.degree. C. The reaction time is preferably from 1 to 15 hours. 
Now, an embodiment in which the resin (P) contains a photo- and/or 
heat-curable group or the resin (P) is used in combination with a photo- 
and/or heat-curable resin will be described below. 
The polymer components containing at least one photo- and/or heat-curable 
group, which may be incorporated into the resin (P), include those 
described in the above-cited literature references. More specifically, the 
polymer components containing the above-described polymerizable functional 
group(s) can be used. 
The content of the polymer component containing at least one photo- and/or 
heat-curable group ranges ordinarily from 1 to 95 parts by weight, 
preferably from 10 to 70 parts by weight, based on 100 parts by weight of 
the polymer segment (.beta.) in the block copolymer (P) and the polymer 
component is preferably contained in the range of from 5 to 40 parts by 
weight per 100 parts by weight of the total polymer components in the 
block copolymer (P). When the photo- and/or heat-curable group-containing 
polymer component is present at least one part by weight based on 100 
parts by weight of the polymer segment (.beta.), curing of the 
photoconductive layer after film formation proceeds sufficiently, and thus 
the effect for improving the releasability of toner image can be obtained. 
On the other hand, in the event of using the polymer component up to 95 
parts by weight based on 100 parts by weight of the polymer segment 
(.beta.), good electrophotographic characteristics of the photoconductive 
layer are obtained and reduction in reproducibility of original in 
duplicated image and occurrence of background fog in non-image areas are 
avoided. 
The photo- and/or heat-curable group-containing block copolymer (P) is 
preferably used in an amount of not more than 40% by weight based on the 
total binder resin. In the range described above, good electrophotographic 
characteristics are obtained. 
The fluorine atom and/or silicon atom-containing resin may also be used in 
combination with a photo- and/or heat-curable resin (D) in the present 
invention. Any of conventionally known curable resins may be used as the 
photo- and/or heat-curable resin (D). For example, resins containing the 
curable group as described with respect to the block copolymer (P) may be 
used. 
Further, conventionally known binder resins for an electrophotographic 
light-sensitive layer are employed. These resins are described, e.g., in 
Takaharu Shibata and Jiro Ishiwatari, Kobunshi, Vol. 17, p. 278 (1968), 
Harumi Miyamoto and Hidehiko Takei, Imaging, Vol. 1973, No. 8, Koichi 
Nakamura (ed.), Kiroku Zairyoyo Binder no Jissai Gijutsu, Ch. 10, C. M.C. 
(1985), Denshishashin Gakkai (ed.), Denshishashinyo Yukikankotai no Genjo 
Symposium (preprint) (1985), Hiroshi Kokado (ed.), Saikin no Kododenzairyo 
to Kankotai no Kaihatsu.multidot.Jitsuyoka, Nippon Kagaku Joho (1986), 
Denshishashin Gakkai (ed.), Denshishashin Gijutsu no Kiso To Oyo, Ch. 5, 
Corona (1988), D. Tatt and S. C. Heidecker, Tappi, Vol. 49, No. 10, p. 439 
(1966 ), E. S. Baltazzi and R. G. Blanchlotte, et al., Photo. Sci. Eng., 
Vol. 16, No. 5, p. 354 (1972), and Nguyen Chank Keh, Isamu Shimizu and 
Eiichi Inoue, Denshishashin Gakkaishi, Vol. 18, No. 2, p. 22 (1980). 
Specific examples of these known binder resins used include olefin polymers 
or copolymers, vinyl chloride copolymers, vinylidene chloride copolymers, 
vinyl alkanoate polymers or copolymers, allyl alkanoate polymers or 
copolymers, polymers or copolymers of styrene or derivatives thereof, 
butadiene-styrene copolymers, isoprene-styrene copolymers, 
butadiene-unsaturated carboxylic ester copolymers, acrylonitrile 
copolymers, methacrylonitrile copolymers, alkyl vinyl ether copolymers, 
acrylic ester polymers or copolymers, methacrylic ester polymers or 
copolymers, styreneacrylic ester copolymers, styrene-methacrylic ester 
copolymers, itaconic diester polymers or copolymers, maleic anhydride 
copolymers, acrylamide copolymers, methacrylamide copolymers, hydroxy 
group-modified silicone resins, polycarbonate resins, ketone resins, 
polyester resins, silicone resins, amide resins, hydroxy group- or carboxy 
group-modified polyester resins, butyral resins, polyvinyl acetal resins, 
cyclized rubber-methacrylic ester copolymers, cyclized rubber-acrylic 
ester copolymers, copolymers containing a heterocyclic ring containing no 
nitrogen atom (the heterocyclic ring including furan, tetrahydrofuran, 
thiophene, dioxane, dioxofuran, lactone, benzofuran, benzothiophene and 
1,3-dioxetane rings), and epoxy resins. 
More specifically, reference can be made to Tsuyoshi Endo, Netsukokasei 
Kobunshi no Seimitsuka, C.M.C. (1986), Yuji Harasaki, Saishin Binder 
Gijutsu Binran, Ch. II-1, Sogo Gijutsu Center (1985), Takayuki Otsu, Acryl 
Jushi no Gosei.multidot.Sekkei to Shinyoto Kaihatsu, Chubu Kei-ei Kaihatsu 
Center Shuppanbu (1985), and Eizo Omori, Kinosei Acryl-Kei Jushi, Techno 
System (1985). 
As described above, when the uppermost layer of light-sensitive element, 
for example, the overcoat layer or the photoconductive layer contains at 
least one binder resin and at least one binder resin (P) for modifying the 
surface thereof, it is preferred that the layer further contains a small 
amount of photo- and/or heat-curable resin (D) and/or a crosslinking agent 
for further improving film curability. 
The amount of photo- and/or heat-curable resin (D) and/or crosslinking 
agent to be added is preferably from 0.01 to 20% by weight, and more 
preferably from 0.1 to 15% by weight, based on the total amount of the 
binder resin (B) and the binder resin (P). In the range described above, 
the effect of improving film curability is obtained without adversely 
affecting the electrophotographic characteristics. 
A combined use of a crosslinking agent is preferable. Any of ordinarily 
employed crosslinking agents may be utilized. Suitable crosslinking agents 
are described, e.g., in Shinzo Yamashita and Tosuke Kaneko (ed.), Kakyozai 
Handbook, Taiseisha (1981 ) and Kobunshi Gakkai (ed.), Kobunshi Data 
Handbook (Kisohen), Baifukan (1986 ). Specific examples of the 
crosslinking agents include the compounds described as the crosslinking 
agents above. 
In addition, monomers containing a polyfunctional polymerizable group 
(e.g., vinyl methacrylate, acryl methacrylate, ethylene glycol diacrylate, 
polyethylene glycol diacrylate, divinyl succinate, divinyl adipate, 
diacryl succinate, 2-methylvinyl methacrylate, trimethylolpropane 
trimethacrylate, divinylbenzene, and pentaerythritol polyacrylate) may 
also be used as the crosslinking agent. 
As described above, the uppermost layer of the light-sensitive element, 
i.e. a layer which will be in contact with a transfer layer, is preferably 
cured after film formation. It is preferred that the binder resin (B), the 
binder resin (P), the curable resin (D), and the crosslinking agent to be 
used in the uppermost layer are so selected and combined that their 
functional groups easily undergo chemical bonding to each other. 
Combinations of functional groups which easily undergo a polymer reaction 
are well known. Specific examples of such combinations are shown in Table 
1 below, wherein a functional group selected from Group A can be combined 
with a functional group selected from Group B. However, the present 
invention should not be construed as being limited thereto. 
TABLE 1 
______________________________________ 
Group A 
Group B 
______________________________________ 
COOH, PO.sub.3 H.sub.2, OH 
##STR11## 
SH, SO.sub.2 Cl, a cyclic acid anhydride group, 
NH.sub.2, 
NCO, NCS, 
NHR, 
SO.sub.2 H 
##STR12## 
##STR13## 
##STR14## 
Y': CH.sub.3, Cl, OCH.sub.3), 
##STR15## 
##STR16## 
______________________________________ 
In Table 1, R.sup.55 and R.sup.56 each represents an alkyl group; R.sup.57, 
R.sup.58, and R.sup.59 each represents an alkyl group or an alkoxy group, 
provided that at least one of them is an alkoxy group; R represents a 
hydrocarbon group; B.sup.1 and B.sup.2 each represent an electron 
attracting group, e.g , -CN, -CF.sub.3, -COR.sup.60, -COOR.sup.60, 
-SO.sub.2 OR.sup.60 (R.sup.60 represents a hydrocarbon group, e.g., 
-C.sub.n H.sub.2n+1 (n: an integer of from 1 to 4), -CH.sub.2 C.sub.6 
H.sub.5, or -C.sub.6 H.sub.5). 
If desired, a reaction accelerator may be added to the binder resin for 
accelerating the crosslinking reaction in the light-sensitive layer. 
The reaction accelerators which may be used for the crosslinking reaction 
forming a chemical bond between functional groups include organic acids 
(e.g., acetic acid, propionic acid, butyric acid, benzenesulfonic acid, 
and p-toluenesulfonic acid), phenols (e.g., phenol, chlorophenol, 
nitrophenol, cyanophenol, bromophenol, naphthol, and dichlorophenol), 
organometallic compounds (e.g., zirconium acetylacetonate, zirconium 
acetylacetone, cobalt acetylacetonate, and dibutoxytin dilaurate), 
dithiocarbamic acid compounds (e.g., diethyldithiocarbamic acid salts), 
thiuram disulfide compounds (e.g., tetramethylthiuram disulfide), and 
carboxylic acid anhydrides (e.g., phthalic anhydride, maleic anhydride, 
succinic anhydride, butylsuccinic anhydride, benzophenone-3,3', 
4,4'-tetracarboxylic acid dianhydride, and trimellitic anhydride). 
The reaction accelerators which may be used for the crosslinking reaction 
involving polymerization include polymerization initiators, such as 
peroxides and azobis compounds. 
After a coating composition for the light-sensitive layer is coated, the 
binder resin is preferably cured by light and/or heat. Heat curing can be 
carried out by drying under severer conditions than those for the 
production of a conventional light-sensitive element. For example, 
elevating the drying temperature and/or increasing the drying time may be 
utilized. After drying the solvent of the coating composition, the film is 
preferably subjected to a further heat treatment, for example, at 
60.degree. to 150.degree. C. for 5 to 120 minutes. The conditions of the 
heat treatment may be made milder by using the above-described reaction 
accelerator in combination. 
Curing of the resin containing a photo-curable functional group can be 
carried out by incorporating a step of irradiation of actinic ray into the 
production line according to the present invention. The actinic rays to be 
used include visible light, ultraviolet light, far ultraviolet light, 
electron beam, X-ray, .gamma.-ray, and .alpha.-ray, with ultraviolet light 
being preferred. Actinic rays having a wavelength range of from 310 to 500 
nm are more preferred. In general, a low-, high- or ultrahigh-pressure 
mercury lamp or a halogen lamp is employed as a light source. Usually, the 
irradiation treatment can be sufficiently performed at a distance of from 
5 to 50 cm for 10 seconds to 10 minutes. 
Now, the latter method for obtaining an electrophotographic light-sensitive 
element having the surface of releasability by applying the compound (S) 
for imparting the desired releasability to the surface of a conventionally 
known electrophotographic light-sensitive element before the formation of 
toner image will be described in detail below. 
The compound (S) is a compound containing a fluorine atom and/or a silicon 
atom. The compound (S) containing a moiety having a fluorine and/or 
silicon atom is not particularly limited in its structure as far as it can 
improve releasability of the surface of electrophotographic 
light-sensitive element, and includes a low molecular weight compound, an 
oligomer, and a polymer. 
When the compound (S) is an oligomer or a polymer, the moiety having a 
fluorine and/or silicon atom includes that incorporated into the main 
chain of the oligomer or polymer and that contained as a substituent in 
the side chain thereof. Of the oligomers and polymers, those containing 
repeating units containing the moiety having a fluorine and/or silicon 
atom as a block are preferred since they adsorb on the surface of 
electrophotographic light-sensitive element to impart good releasability. 
The fluorine atom and/or silicon atom-containing moieties include those 
described with respect to the resin (P) above. 
Specific examples of the compound (S) containing a fluorine and/or silicon 
atom which can be used in the present invention include fluorine and/or 
silicon-containing organic compounds described, for example, in Tokiyuki 
Yoshida, et al. (ed.), Shin-ban Kaimenkasseizai Handbook, Kogaku Tosho 
(1987), Takao Karikome, Saishin Kaimenkasseizai Oyo Gijutsu, C.M.C. 
(1990), Kunio Ito (ed.), Silicone Handbook, Nikkan Kogyo Shinbunsha 
(1990), Takao Karikome, Tokushukino Kaimenkasseizai, C.M.C. (1986), and 
A.M. Schwartz, et al., Surface Active Agents and Detergents, Vol. II. 
Further, the compound (S) according to the present invention can be 
synthesized by utilizing synthesis methods as described, for example, in 
Nobuo Ishikawa, Fussokagobutsu no Gosei to Kino, C.M.C. (1987), Jiro 
Hirano et al. (ed.), Ganfussoyukikagobutsu--Sono Gosei to Oyo, Gijutsu 
Joho Kokai (1991), and Mitsuo Ishikawa, Yukikeiso Senryaku Shiryo, Chapter 
3, Science Forum (1991). 
Specific examples of polymer components having the fluorine atom and/or 
silicon atom-containing moiety used in the oligomer or polymer include 
those described with respect to the resin (P) above. 
When the compound (S) is a so-called block copolymer, the compound (S) may 
be any type of copolymer as far as it contains the fluorine atom and/or 
silicon atom-containing polymer components as a block. The term "to be 
contained as a block" means that the compound (S) has a polymer segment 
comprising at least 70% by weight of the fluorine atom and/or silicon 
atom-containing polymer component based on the weight of the polymer 
segment. The forms of blocks include an A-B type block, an A-B-A type 
block, a B-A-B type block, a graft type block, and a starlike type block 
as schematically illustrated with respect to the resin (P) above. These 
block copolymers can be synthesized according to the methods described 
with respect to the resin (P) above. 
By the application of compound (S) onto the surface of electrophotographic 
light-sensitive element, the surface is modified to have the desired 
releasability. The term "application of compound (S) onto the surface of 
electrophotographic light-sensitive element" means that the compound is 
supplied on the surface of electrophotographic light-sensitive element to 
form a state wherein the compound (S) is adsorbed or adhered thereon. 
In order to apply the compound (S) to the surface of electrophotographic 
light-sensitive element, conventionally known various methods can be 
employed. For example, methods using an air doctor coater, a blade coater, 
a knife coater, a squeeze coater, a dip coater, a reverse roll coater, a 
transfer roll coater, a gravure coater, a kiss roll coater, a spray 
coater, a curtain coater, or a calender coater as described, for example, 
in Yuji Harasaki, Coating Kogaku, Asakura Shoten (1971), Yuji Harasaki, 
Coating Hoshiki, Maki Shoten (1979), and Hiroshi Fukada, Hot-melt Secchaku 
no Jissai Kobunshi Kankokai (1979) can be used. 
A method wherein cloth, paper or felt impregnated with the compound (S) is 
pressed on the surface of light-sensitive element, a method of pressing a 
curable resin impregnated with the compound (S), a method wherein the 
light-sensitive element is wetted with a non-aqueous solvent containing 
the compound (S) dissolved therein, and then dried to remove the solvent, 
and a method wherein the compound (S) dispersed in a non-aqueous solvent 
is migrated and adhered on the surface of light-sensitive element by 
electrophoresis according to a wet-type electrodeposition method as 
described hereinafter can also be employed. 
Further, the compound (S) can be applied on the surface of light-sensitive 
element by utilizing a non-aqueous solvent containing the compound (S) 
according to an ink jet method, followed by drying. The ink jet method can 
be performed with reference to the descriptions in Shin Ohno (ed.), 
Non-impact Printing, C.M.C. (1986). More specifically, a Sweet process or 
Hartz process of a continuous jet type, a Winston process of an 
intermittent jet type, a pulse jet process of an ink on-demand type, a 
bubble jet process, and a mist process of an ink mist type are 
illustrated. 
In any system, the compound (S) itself or diluted with a solvent is filled 
in an ink tank or ink head cartridge in place of an ink to use. The 
solution of compound (S) used ordinarily has a viscosity of from 1 to 10 
cp and a surface tension of from 30 to 60 dyne/cm, and may contain a 
surface active agent, or may be heated if desired. Although a diameter of 
ink droplet is in a range of from 30 to 100 .mu.m due to a diameter of an 
orifice of head in a conventional ink jet printer in order to reproduce 
fine letters, droplets of a larger diameter can also be used in the 
present invention. In such a case, an amount of jet of the compound (S) 
becomes large and thus a time necessary for the application can be 
shortened. Further, to use multiple nozzles is very effective to shorten 
the time for application. 
When silicone rubber is used as the compound (S), it is preferred that 
silicone rubber is provided on a metal axis to cover and the resulting 
silicone rubber roller is directly pressed on the surface of 
electrophotographic light-sensitive element. In such a case, a nip 
pressure is ordinarily in a range of from 0.5 to 10 Kgf/cm.sup.2 and a 
time for contact is ordinarily in a range of from 1 second to 30 minutes. 
Also, the light-sensitive element and/or silicone rubber roller may be 
heated up to a temperature of 150.degree. C. According to this method, it 
is believed that a part of low molecular weight components contained in 
silicone rubber is moved from the silicone rubber roller onto the surface 
of light-sensitive element during the press. The silicone rubber may be 
swollen with silicone oil. Moreover, the silicone rubber may be a form of 
sponge and the sponge roller may be impregnated with silicone oil or a 
solution of silicone surface active agent. 
The application method of the compound (S) is not particularly limited, and 
an appropriate method can be selected depending on a state (i.e., liquid, 
wax or solid) of the compound (S) used. A flowability of the compound (S) 
can be controller using a heat medium, if desired. 
The application of compound (S) is preferably performed by a means which is 
easily incorporated into an electrophotographic apparatus. 
An amount of the compound (S) applied to the surface of electrophotographic 
light-sensitive element is not particularly limited and is adjusted in a 
range wherein the electrophotographic characteristics of light-sensitive 
element do not adversely affected in substance. Ordinarily, a thickness of 
the coating is sufficiently 1 .mu.m or less. By the formation of weak 
boundary layer as defined in Bikerman, The Science of Adhesive Joints, 
Academic Press (1961), the releasability-imparting effect of the present 
invention can be obtained. Specifically, when an adhesive strength of the 
surface of an electrophotographic light-sensitive element to which the 
compound (S) has been applied is measured according to the method 
described above, the resulting adhesive strength is preferably not more 
than 100 gram.multidot.force. 
In accordance with the present invention, the surface of 
electrophotographic light-sensitive element is provided with the desired 
releasability by the application of compound (S ), and the light-sensitive 
element can be repeatedly employed as far as the releasability is 
maintained. Specifically, the application of compound (S) is not always 
necessarily whenever a series of steps for the preparation of a printing 
plate according to the present invention is repeated. The application may 
be suitably performed by an appropriate combination of a light-sensitive 
element, an ability of compound (S) for imparting the releasability and a 
means for the application. 
Any conventionally known electrophotographic light-sensitive element can be 
employed in the present invention. 
Suitable examples of electrophotographic light-sensitive element used are 
described, for example, in R. M. Schaffert, Electrophotography, Forcal 
Press, London (1980), S. W. Ing, M. D. Tabak and W. E. Haas, 
Electrophotography Fourth International Conference, SPSE (1983), Isao 
Shinohara, Hidetoshi Tsuchida and Hideaki Kusakawa (ed.), Kirokuzairyo to 
Kankoseijushi, Gakkai Shuppan Center (1979), Hiroshi Kokado, Kagaku to 
Kogyo, Vol. 39, No. 3, p. 161 (1986), Saikin no Kododen Zairyo to Kankotai 
no Kaihatsu-Jitsuyoka, Nippon Kagaku Joho Shuppanbu (1986), Denshishashin 
Gakkai (ed.), Denshishashin no Kiso to Oyo, Corona (1986), and 
Denshishashin Gakkai (ed.), Denshishashinyo Yukikankotai no Genjo 
Symposium (preprint), (1985). 
A photoconductive layer for the electrophotographic light-sensitive element 
which can be used in the present invention is not particularly limited, 
and any known photoconductive layer may be employed. 
Specifically, the photoconductive layer includes a single layer made of a 
photoconductive compound itself and a photoconductive layer comprising a 
binder resin having dispersed therein a photoconductive compound. The 
dispersed type photoconductive layer may have a single layer structure or 
a laminated structure. 
The photoconductive compounds used in the present invention may be 
inorganic compounds or organic compounds. 
Inorganic photoconductive compounds used in the present invention include 
those conventionally known for example, zinc oxide, titanium oxide, zinc 
sulfide, cadmium sulfide, selenium, selenium-tellurium, amorphous silicon, 
lead sulfide. These compounds are used together with a binder resin to 
form a photoconductive layer, or they are used alone to form a 
photoconductive layer by vacuum deposition or spattering. 
Where an inorganic photoconductive compound, e.g., zinc oxide or titanium 
oxide, is used, a binder resin is usually used in an amount of from 10 to 
100 parts by weight, and preferably from 15 to 40 parts by weight, per 100 
parts by weight of the inorganic photoconductive compound. 
Organic photoconductive compounds used may be selected from conventionally 
known compounds. Suitable photoconductive layers containing an organic 
photoconductive compound include (i) a layer mainly comprising an organic 
photoconductive compound, a sensitizing dye, and a binder resin as 
described, e.g., in JP-B-37-17162, JP-B-62-51462, JP-A-52-2437, 
JP-A-54-19803, JP-A-56-107246, and JP-A-57-161863; (ii) a layer mainly 
comprising a charge generating agent, a charge transporting agent, and a 
binder resin as described, e.g., in JP-A-56-146145, JP-A-60-17751, 
JP-A-60-17752, JP-A-60-17760, JP-A-60-254142, and JP-A-62-54266; and (iii) 
a double-layered structure containing a charge generating agent and a 
charge transporting agent in separate layers as described, e.g., in 
JP-A-60-230147, JP-A-60-230148, and JP-A-60-238853. 
The photoconductive layer of the electrophotographic light-sensitive 
element according to the present invention may have any of the 
above-described structure. 
The organic photoconductive compounds which may be used in the present 
invention include (a) triazole derivatives described, e.g., in U.S. Pat. 
No. 3,112,197, (b) oxadiazole derivatives described, e.g., in U.S. Pat. 
No. 3,189,447, (c) imidazole derivatives described in JP-B-37-16096, (d) 
polyarylalkane derivatives described, e.g., in U.S. Pat. Nos. 3,615,402, 
3,820,989, and 3,542,544, JP-B-45-555, JP-B-51-10983, JP-A-51-93224, 
JP-A-55-108667 , JP-A-55-156953 , and JP-A-56-36656, (e) pyrazoline 
derivatives and pyrazolone derivatives described, e.g. , in U.S. Pat. Nos. 
3,180,729 and 4,278,746, JP-A-55-88064, JP-A-55-88065, JP-A-49-105537, 
JP-A-55-51086, JP-A-56-80051, JP-A-56-88141, JP-A-57-45545, 
JP-A-54-112637, and JP-A-55-74546, (f) phenylenediamine derivatives 
described, e.g., in U.S. Pat. No. 3,615,404, JP-B-51-10105, JP-B-46-3712, 
JP-B-47-28336, JP-A-54-83435, JP-A-54-110836, and JP-A-54-119925, (g) 
arylamine derivatives described, e.g., in U.S. Pat. Nos. 3,567,450, 
3,180,703, 3,240,597, 3,658,520, 4,232,103, 4,175,961, and 4,012,376, 
JP-B-49-35702, West German Patent (DAS) 1,110,518, JP-B-39-27577, 
JP-A-55-144250, JP-A-56-119132, and JP-A-56-22437, (h) amino-substituted 
chalcone derivatives described, e.g., in U.S. Pat. No. 3,526,501, (i) 
N,N-bicarbazyl derivatives described, e.g., in U.S. Pat. No. 3,542,546, 
(j) oxazole derivatives described, e.g., in U.S. Pat. No. 3,257,203, (k) 
styrylanthracene derivatives described, e.g., in JP-A-56-46234, (1) 
fluorenone derivatives described, e.g., in JP-A-54-110837, (m) hydrazone 
derivatives described, e.g., in U.S. Pat. No. 3,717,462, JP-A-54-59143 
(corresponding to U.S. Pat. No. 4,150,987), JP-A-55-52063, JP-A-55-52064, 
JP-A-55-46760, JP-A-55-85495, JP-A-57-11350, JP-A-57-148749, and 
JP-A-57-104144, (n) benzidine derivatives described, e.g., in U.S. Pat. 
Nos. 4,047,948, 4,047,949, 4,265,990, 4,273,846, 4,299,897, and 4,306,008, 
(o) stilbene derivatives described, e.g., in JP-A-58-190953, 
JP-A-59-95540, JP-A-59-97148, JP-A-59-195658, and JP-A-62-36674, (p) 
polyvinylcarbazole and derivatives thereof described in JP-B-34-10966, (q) 
vinyl polymers, such as polyvinylpyrene, polyvinylanthracene, 
poly-2-vinyl-4-(4'-dimethylaminophenyl)-5-phenyloxazole, and 
poly-3-vinyl-N-ethylcarbazole, described in JP-B-43-18674 and 
JP-B-43-19192, (r) polymers, such as polyacenaphthylene, polyindene, and 
an acenaphthylene-styrene copolymer, described in JP-B-43-19193, (s) 
condensed resins, such as pyrene-formaldehyde resin, 
bromopyrene-formaldehyde resin, and ethyl-carbazole-formaldehyde resin, 
described, e.g., in JP-B-56-13940, and (t) triphenylmethane polymers 
described in JP-A-56-90833 and JP-A-56-161550. 
The organic photoconductive compounds which can be used in the present 
invention are not limited to the above-described compounds (a) to (t), and 
any of known organic photoconductive compounds may be employed in the 
present invention. The organic photoconductive compounds may be used 
either individually or in combination of two or more thereof. 
The sensitizing dyes which can be used in the photoconductive layer of (i) 
include those conventionally known as described, e.g., in Denshishashin, 
Vol. 12, p. 9 (1973) and Yuki Gosei Kagaku, Vol. 24, No. 11, p. 1010 
(1966). Specific examples of suitable sensitizing dyes include pyrylium 
dyes described, e.g., in U.S. Pat. Nos. 3,141,770 and 4,283,475, 
JP-A-48-25658, and JP-A-62-71965; triarylmethane dyes described, e.g., in 
Applied Optics Supplement, vol. 3, p. 50 (1969) and JP-A-50-39548; cyanine 
dyes described, e.g., in U.S. Pat. No. 3,597,196; and styryl dyes 
described, e.g., in JP-A-60-163047, JP-A-59-164588, and JP-A-60-252517. 
The charge generating agents which can be used in the photoconductive layer 
of (ii) include various conventionally known charge generating agents, 
either organic or inorganic, such as selenium, selenium-tellurium, cadmium 
sulfide, zinc oxide, and organic pigments, for example, (1) azo pigments 
(including monoazo, bisazo, and trisazo pigments) described, e.g., in U.S. 
Pat. Nos. 4,436,800 and 4,439,506, JP-A-47-37543, JP-A-58-123541, 
JP-A-58-192042, JP-A-58-219263, JP-A-59-78356, JP-A-60-179746, 
JP-A-61-148453, JP-A-61-238063, JP-B-60-5941, and JP-B-60-45664, (2) 
metal-free or metallized phthalocyanine pigments described, e.g., in U.S. 
Pat. Nos. 3,397,086 and 4,666,802, JP-A-51-90827, and JP-A-52-55643, (3) 
perylene pigments described, e.g., in U.S. Pat. No. 3,371,884 and 
JP-A-47-30330, (4) indigo or thioindigo derivatives described, e.g., in 
British Patent 2,237,680 and JP-A-47-30331, (5) quinacridone pigments 
described, e.g., in British Patent 2,237,679 and JP-A-47-30332, (6) 
polycyclic quinone dyes described, e.g., in British Patent 2,237,678, 
JP-A-59-184348, JP-A-62-28738, and JP-A-47-18544, (7) bisbenzimidazole 
pigments described, e.g., in JP-A-47-30331 and JP-A-47-18543, (8) 
squarylium salt pigments described, e.g., in U.S. Pat. Nos. 4,396,610 and 
4,644,082, and (9) azulenium salt pigments described, e.g., in 
JP-A-59-53850 and JP-A-61-212542. 
These organic pigments may be used either individually or in combination of 
two or more thereof. 
The charge transporting agents which can be used in the photoconductive 
layer of (ii) include these exemplified as the organic photoconductive 
compound described above. 
With respect to a mixing ratio of the organic photoconductive compound and 
a binder resin, particularly the upper limit of the organic 
photoconductive compound is determined depending on the compatibility 
between these materials. The organic photoconductive compound, if added in 
an amount over the upper limit, may undergo undesirable crystallization. 
The lower the content of the organic photoconductive compound, the lower 
the electrophotographic sensitivity. Accordingly, it is desirable to use 
the organic photoconductive compound in an amount as much as possible 
within such a range that crystallization does not occur. In general, 5 to 
120 parts by weight, and preferably from 10 to 100 parts by weight, of the 
organic photoconductive compound is used per 100 parts by weight of the 
total binder resins. 
The binder resins (B) which can be used in the light-sensitive element 
according to the present invention include those for conventionally known 
electrophotographic light-sensitive elements. A preferred weight average 
molecular weight of the binder resin is from 5.times.10.sup.3 to 
1.times.10.sup.6, and particularly from 2.times.10.sup.4 to 
5.times.10.sup.5. A preferred glass transition point of the binder resin 
is from -40.degree. to 200.degree. C., and particularly from -10.degree. 
to 140.degree. C. 
Conventional binder resins which may be used in the present invention are 
described, e.g., in Takaharu Shibata and Jiro Ishiwatari, Kobunshi, Vol. 
17, p. 278 (1968), Harumi Miyamoto and Hidehiko Takei, Imaging, Vol. 1973, 
No. 8, Koichi Nakamura (ed.), Kiroku Zairyoyo Binder no Jissai Gijutsu, 
Ch. 10, C.M.C. (1985), Denshishashin Gakkai (ed.), Denshishashinyo 
Yukikankotai no Genjo Symposium (preprint) (1985), Hiroshi Kokado (ed.), 
Saikin no Kododen Zairyo to Kankotai no Kaihatsu.multidot.Jitsuyoka, 
Nippon Kagaku Joho (1986), Denshishashin Gakkai (ed.), Denshishashin 
Gijutsu no Kiso to Oyo, Ch. 5, Corona (1988), D. Tatt and S.C. Heidecker, 
Tappi, Vol. 49, No. 10, p. 439 (1966), E. S. Baltazzi and R. G. 
Blanchlotte, et al., Photo. Sci. Eng., Vol. 16, No. 5, p. 354 (1972), and 
Nguyen Chank Keh, Isamu Shimizu and Eiichi Inoue, Denshi Shashin 
Gakkaishi, Vol. 18, No. 2, p. 22 (1980). 
Specific examples of these known binder resins used include olefin polymers 
or copolymers, vinyl chloride copolymers, vinylidene chloride copolymers, 
vinyl alkanoate polymers or copolymers, allyl alkanoate polymers or 
copolymers, polymers or copolymers of styrene or derivatives thereof, 
butadiene-styrene copolymers, isoprene-styrene copolymers, 
butadiene-unsaturated carboxylic ester copolymers, acrylonitrile 
copolymers, methacrylonitrile copolymers, alkyl vinyl ether copolymers, 
acrylic ester polymers or copolymers, methacrylic ester polymers or 
copolymers, styrene-acrylic ester copolymers, styrene-methacrylic ester 
copolymers, itaconic diester polymers or copolymers, maleic anhydride 
copolymers, acrylamide copolymers, methacrylamide copolymers, hydroxy 
group-modified silicone resins, polycarbonate resins, ketone resins, 
polyester resins, silicone resins, amide resins, hydroxy group- or carboxy 
group-modified polyester resins, butyral resins, polyvinyl acetal resins, 
cyclized rubber-methacrylic ester copolymers, cyclized rubber-acrylic 
ester copolymers, copolymers containing a heterocyclic ring containing no 
nitrogen atom (the heterocyclic ring including furan, tetrahydrofuran, 
thiophene, dioxane, dioxofuran, lactone, benzofuran, benzothiophene and 
1,3-dioxetane rings), and epoxy resins. 
Further, the electrostatic characteristics of the photoconductive layer are 
improved by using, as a binder resin (B), a resin having a relatively low 
molecular weight (e.g., a weight average molecular weight of from 10.sup.3 
to 10.sup.4) and containing an acidic group such as a carboxy group, a 
sulfo group or a phosphono group. For instance, JP-A-63-217354 discloses a 
resin having polymer components containing an acidic group at random in 
the polymer main chain, JP-A-64-70761 discloses a resin having an acidic 
group bonded at one terminal of the polymer main chain, JP-A-2-67563, 
JP-A-2-236561, JP-A-2-238458, JP-A-2-236562 and JP-A-2-247656 disclose a 
resin of graft type copolymer having an acidic group bonded at one 
terminal of the polymer main chain or a resin of graft type copolymer 
containing acidic groups in the graft portion, and JP-A-3-181948 discloses 
an AB block copolymer containing acidic groups as a block. 
Moreover, in order to obtain a satisfactorily high mechanical strength of 
the photoconductive layer which may be insufficient by only using such a 
low molecular weight resin, a medium to high molecular weight resin is 
preferably used together with the low molecular weight resin. For 
instance, JP-A-2-68561 discloses a thermosetting resin capable of forming 
crosslinked structures between polymers, JP-A-2-68562 discloses a resin 
partially having crosslinked structures, and JP-A-2-69759 discloses a 
resin of graft type copolymer having an acidic group bonded at one 
terminal of the polymer main chain. 
Also, in order to maintain the relatively stable performance even when 
ambient conditions are widely fluctuated, a specific medium to high 
molecular weight resin is employed in combination. For instance, 
JP-A-3-29954, JP-A-3-77954, JP-A-3-92861 and JP-A-3-53257 disclose a resin 
of graft type copolymer having an acidic group bonded at the terminal of 
the graft portion or a resin of graft type copolymer containing acidic 
groups in the graft portion. Moreover, JP-A-3-206464 and JP-A-3-223762 
discloses a medium to high molecular weight resin of graft type copolymer 
having a graft portion formed from an AB block copolymer comprising an A 
block containing acidic groups and a B block containing no acidic group. 
In a case of using these resins, the photoconductive substance is uniformly 
dispersed to form a photoconductive layer having good smoothness. Also, 
excellent electrostatic characteristics can be maintained even when 
ambient conditions are fluctuated or when a scanning exposure system using 
a semiconductor laser beam is utilized for the image exposure. 
The photoconductive layer usually has a thickness of from 1 to 100 .mu.m, 
and preferably from 10 to 50 .mu.m. 
Where a photoconductive layer functions as a charge generating layer of a 
laminated type light-sensitive element composed of a charge generating 
layer and a charge transporting layer, the charge generating layer has a 
thickness of from 0.01 to 5 .mu.m, and preferably from 0.05 to 2 .mu.m. 
Depending on the kind of a light source for exposure, for example, visible 
light or semiconductor laser beam, various dyes may be used as spectral 
sensitizers. The sensitizing dyes used include carbonium dyes, 
diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, phthalein 
dyes, polymethine dyes (including oxonol dyes, merocyanine dyes, cyanine 
dyes, rhodacyanine dyes, and styryl dyes), and phthalocyanine dyes 
(including metallized dyes), as described e.g., in Harumi Miyamoto and 
Hidehiko Takei, Imaging, Vol. 1973, No. 8, p. 12, C. J. Young et al., RCA 
Review, Vol. 15, p. 469 (1954), Kohei Kiyota et al., Denkitsushin Gakkai 
Ronbunshi, Vol. J 63-C, No. 2, p. 97 (1980), Yuji Harasaki et al., Kogyo 
Kagaku Zasshi, Vol. 66, p. 78 and 188 (1963), and Tadaaki Tani, Nihon 
Shashin Gakkaishi, Vol. 35, p. 208 (1972). 
Specific examples of carbonium dyes, triphenylmethane dyes, xanthene dyes, 
and phthalein dyes are described, e.g., in JP-B-51-452, JP-A-50-90334, 
JP-A-50-114227, JP-A-53-39130, JP-A-53-82353, U.S. Pat. Nos. 3,052,540 and 
4,054,450, and JP-A-57-16456. 
Usable polymethine dyes, such as oxonol dyes, merocyanine dyes, cyanine 
dyes, and rhodacyanine dyes, are described in F. M. Hamer, The Cyanine 
Dyes and Related Compounds. Specific examples of these dyes are described, 
e.g., in U.S. Pat. Nos. 3,047,384, 3,110,591, 3,121,008, 3,125,447, 
3,128,179, 3,132,942, and 3,622,317, British Patents 1,226,892, 1,309,274, 
and 1,405,898, JP-B-48-7814, and JP-B-55-18892. 
Further, polymethine dyes capable of performing spectral sensitization in 
the near infrared to infrared region of 700 nm or more include those 
described, e.g., in JP-A-47-840, JP-A-47-44180, JP-B-51-41061, 
JP-A-49-5034, JP-A-49-45122, JP-A-57-46245, JP-A-56-35141, JP-A-57-157254, 
JP-A-61-26044, JP-A-61-27551, U.S. Pat. Nos. 3,619,154 and 4,175,956, and 
Research Disclosure, No. 216, pp. 117-118 (1982). 
The light-sensitive element of the present invention is excellent in that 
the characteristics thereof hardly vary with the combined use of various 
sensitizing dyes. 
If desired, the light-sensitive element may further contain various 
additives conventionally known for electrophotographic light-sensitive 
elements. The additives include chemical sensitizers for increasing 
electrophotographic sensitivity and plasticizers or surface active agents 
for improving film properties. 
Suitable examples of the chemical sensitizers include electron attracting 
compounds such as a halogen, benzoquinone, chloranil, fluoranil, bromanil, 
dinitrobenzene, anthraquinone, 2,5-dichlorobenzoquinone, nitrophenol, 
tetrachlorophthalic anhydride, phthalic anhydride, maleic anhydride, 
N-hydroxymaleimide, N-hydroxyphthalimide, 
2,3-dichloro-5,6-dicyanobenzoquinone, dinitrofluorenone, 
trinitrofluorenone, tetracyanoethylene, nitrobenzoic acid, and 
dinitrobenzoic acid; and polyarylalkane compounds, hindered phenol 
compounds and p-phenylenediamine compounds as described in the literature 
references cited in Hiroshi Kokado, et al., Saikin no Kododen Zairyo to 
Kankotai no Kaihatsu.multidot.Jitsuyoka, Chs. 4 to 6, Nippon Kagaku Joho 
(1986). In addition, the compounds as described in JP-A-58-65439, 
JP-A-58-102239, JP-A-58-129439, and JP-A-62-71965 may also be used. 
Suitable examples of the plasticizers, which may be added for improving 
flexibility of a photoconductive layer, include dimethyl phthalate, 
dibutyl phthalate, dioctyl phthalate, diphenyl phthalate, triphenyl 
phosphate, diisobutyl adipate, dimethyl sebacate, dibutyl sebacate, butyl 
laurate, methyl phthalyl glycolate, and dimethyl glycol phthalate. The 
plasticizer can be added in an amount that does not impair electrostatic 
characteristics of the photoconductive layer. 
The amount of the additive to be added is not particularly limited, but 
ordinarily ranges from 0.001 to 2.0 parts by weight per 100 parts by 
weight of the photoconductive substance. 
The photoconductive layer of the present invention can be provided on a 
conventionally known support. In general, a support for an 
electrophotographic light-sensitive layer is preferably electrically 
conductive. The electrically conductive support which can be used includes 
a substrate (e.g., a metal plate, paper, or a plastic sheet) having been 
rendered conductive by impregnation with a low-resistant substance, a 
substrate whose back side (opposite to the light-sensitive layer side) is 
rendered conductive and further having coated thereon at least one layer 
for, for example, curling prevention, the above-described substrate having 
formed on the surface thereof a water-resistant adhesive layer, the 
above-described substrate having on the surface thereof at least one 
precoat layer, and a paper substrate laminated with a plastic film on 
which aluminum, etc. has been vacuum deposited. 
Specific examples of the conductive substrate and materials for rendering 
non-conductive substrates electrically conductive are described, for 
example, in Yukio Sakamoto, Denshishashin, Vol. 14, No. 1, pp. 2-11 
(1975), Hiroyuki Moriga, Nyumon Tokushushi no Kagaku, Kobunshi Kankokai 
(1975), and M. F. Hoover, J. Macromol. Sci. Chem., Vol. A-4, No. 6, pp. 
1327-1417 (1970). 
Now, the formation of toner image on the electrophotographic 
light-sensitive element whose surface has releasability will be described 
in detail below. 
When the releasability of surface is insufficient, the compound (S) can be 
applied to the surface in order to obtain the desired releasability before 
the start of electrophotographic process. For the formation of toner 
image, a conventional electro-photographic process can be utilized. 
Specifically, each step of charging, light exposure, development and 
fixing is performed in a conventionally known manner. 
In order to form the toner image by an electrophotographic process 
according to the present invention, any methods and apparatus 
conventionally known can be employed. 
The developers which can be used in the present invention include 
conventionally known developers for electrostatic photography, either dry 
type or liquid type. For example, specific examples of the developer are 
described in Denshishashin Gijutsu no Kiso to Oyo, supra, pp. 497-505, 
Koichi Nakamura (ed.), Toner Zairyo no Kaihatsu.multidot.Jitsuyoka, Ch. 3, 
Nippon Kagaku Joho (1985), Gen Machida, Kirokuyo Zairyo to Kankosei Jushi, 
pp. 107-127 (1983), and Denshishasin Gakkai (ed.), Imaging, Nos. 2-5, 
"Denshishashin no 
Genzo.multidot.Teichaku.multidot.Taiden.multidot.Tensha", Gakkai Shuppan 
Center. 
Dry developers practically used include one-component magnetic toners, 
two-component toners, one-component non-magnetic toners, and capsule 
toners. Any of these dry developers may be employed in the present 
invention. 
The typical liquid developer is basically composed of an insulating organic 
solvent, for example, an isoparaffinic aliphatic hydrocarbon (e.g., Isopar 
H or Isopar G (manufactured by Esso Chemical Co.), Shellsol 70 or Shellsol 
71 (manufactured by Shell Oil Co.) or IP-Solvent 1620 (manufactured by 
Idemitsu Petro-Chemical Co., Ltd.)) as a dispersion medium, having 
dispersed therein a colorant (e.g., an organic or inorganic dye or 
pigment) and a resin for imparting dispersion stability, fixability, and 
chargeability to the developer (e.g., an alkyd resin, an acrylic resin, a 
polyester resin, a styrene-butadiene resin, and rosin). If desired, the 
liquid developer can contain various additives for enhancing charging 
characteristics or improving image characteristics. 
The colorant is appropriately selected from known dyes and pigments, for 
example, benzidine type, azo type,-azomethine type, xanthene type, 
anthraquinone type, phthalocyanine type (including metallized type), 
titanium white, nigrosine, aniline black, and carbon black. 
Other additives include, for example, those described in Yuji Harasaki, 
Denshishashin, Vol. 16, No. 2, p. 44, such as di-2-ethylhexylsufosuccinic 
acid metal salts, naphthenic acid metal salts, higher fatty acid metal 
salts, alkylbenzenesulfonic acid metal salts, alkylphosphoric acid metal 
salts, lecithin, polyvinylpyrrolidone, copolymers containing a maleic acid 
monoamido component, coumarone-indene resins, higher alcohols, polyethers, 
polysiloxanes, and waxes. 
With respect to the content of each of the main components of the liquid 
developer, toner particles mainly comprising a resin (and, if desired, a 
colorant) are preferably present in an amount of from 0.5 to 50 parts by 
weight per 1000 parts by weight of a carrier liquid. If the toner content 
is less than 0.5 part by weight, the image density is insufficient, and if 
it exceeds 50 parts by weight, the occurrence of fog in the non-image 
areas may be tended to. 
If desired, the above-described resin for dispersion stabilization which is 
soluble in the carrier liquid is added in an amount of from about 0.5 to 
about 100 parts by weight per 1000 parts by weight of the carrier liquid. 
The above-described charge control agent can be preferably added in an 
amount of from 0.001 to 1.0 part by weight per 1000 parts by weight of the 
carrier liquid. Other additives may be added to the liquid developer, if 
desired. The upper limit of the total amount of other additives is 
determined, depending on electrical resistance of the liquid developer. 
Specifically, the amount of each additive should be controlled so that the 
liquid developer exclusive of toner particles has an electrical 
resistivity of not less than 10.sup.9 .OMEGA.cm. If the resistivity is 
less than 10.sup.9 .OMEGA.cm, a continuous gradation image of good quality 
can hardly be obtained. 
The liquid developer can be prepared, for example, by mechanically 
dispersing a colorant and a resin in a dispersing machine, e.g., a sand 
mill, a ball mill, a jet mill, or an attritor, to produce colored 
particles, as described, for example, in JP-B-35-5511, JP-B-35-13424, 
JP-B-50-40017, JP-B-49-98634, JP-B-58-129438, and JP-A-61-180248. 
The colored particles may also be obtained by a method comprising preparing 
dispersed resin grains having a fine grain size and good monodispersity in 
accordance with a non-aqueous dispersion polymerization method and 
coloring the resulting resin grains. In such a case, the dispersed grains 
prepared can be colored by dyeing with an appropriate dye as described, 
e.g., in JP-A-57-48738, or by chemical bonding of the dispersed grains 
with a dye as described, e.g., in JP-A-53-54029. It is also effective to 
polymerize a monomer already containing a dye at the polymerization 
granulation to obtain a dye-containing copolymer as described, e.g., in 
JP-B-44-22955. 
Particularly, a combination of a scanning exposure system using a laser 
beam based on digital information and a development system using a liquid 
developer is an advantageous process since the process is particularly 
suitable to form highly accurate images. 
One specific example of the methods for preparing a color transfer image is 
illustrated below. An electrophotographic light-sensitive element is 
positioned on a flat bed by a register pin system and fixed on the flat 
bed by air suction from the backside. Then it is charged by means of a 
charging device, for example, the device as described in Denshishashin 
Gakkai (ed.), Denshishashin Gijutsu no Kiso to Oyo, p. 212 et. seq., 
Corona Sha (1988). A corotron or scotron system is usually used for the 
charging process. In a preferred charging process, the charging conditions 
may be controlled by a feedback system of the information on charged 
potential from a detector connected to the light-sensitive element thereby 
to control the surface potential within a predetermined range. 
Thereafter, the charged light-sensitive element is exposed to light by 
scanning with a laser beam in accordance with the system described, for 
example, in ibidem, p. 254 et seq. 
Toner development is then conducted using a liquid developer. The 
light-sensitive element charged and exposed is removed from the flat bed 
and developed according to a wet type developing method as described, for 
example, in ibidem, p. 275 et seq. The exposure mode is determined in 
accordance with the toner image development mode. Specifically, in case of 
reversal development, a negative image is irradiated with a laser beam, 
and a toner having the same charge polarity as that of the charged 
light-sensitive element is electrodeposited on the exposed area with a 
bias voltage applied. For the details, reference can be made to ibidem, p. 
157 et seq. 
After the toner development, the light-sensitive element is squeezed to 
remove the excess developer as described in ibidem, p. 283 and dried. 
Preferably, the light-sensitive element is rinsed with the carrier liquid 
used in the liquid developer before squeezing. 
On the toner image thus-formed on the light-sensitive element, a peelable 
transfer layer is then provided. 
Now, the transfer layer which can be used in the present invention will be 
described in greater detail below. 
The transfer layer of the present invention is a layer having a function of 
transferring the toner image from the light-sensitive element to a primary 
receptor and then to a receiving material which provides a support for a 
printing plate, and of being removed upon a chemical reaction treatment to 
prepare a printing plate. 
Therefore, it is desirable that the transfer layer has thermoplasticity 
sufficient for efficient and easy transfer of toner image formed on the 
light-sensitive element to a primary receptor and then to a receiving 
material without the occurence of image degradation and irrespective of 
the kind of the receiving material, and that the transfer layer is easily 
removed upon a chemical reaction treatment. 
The transfer layer of the present invention is ordinarily colorless and 
transparent but may be colored and/or opaque, if desired. 
The transfer layer is preferred to be transferred under conditions of 
temperature of not more than 180.degree. C. and/or pressure of not more 
than 30 Kgf/cm.sup.2, more preferably under conditions of temperature of 
not more than 160.degree. C. and/or pressure of not more than 20 
Kgf/cm.sup.2. When the transfer conditions are lower than the 
above-described upper limit, there is no problem in practice since a 
large-sized apparatus is almost unnecessary in order to maintain the heat 
capacity and pressure sufficient for release of the transfer layer from 
the surface of light-sensitive element and transfer to a primary receptor 
and then to a receiving material, and the transfer is sufficiently 
performed at an appropriate transfer speed. The lower limit of transfer 
conditions is preferably not less than room temperature and/or pressure of 
not less than 100 gf/cm.sup.2. 
Thus, the resin (A) constituting the transfer layer of the present 
invention is a resin which is thermoplastic and capable of being removed 
upon a chemical reaction treatment. 
With respect to thermal property of the resin (A), a glass transition point 
thereof is preferably not more than 140.degree. C., more preferably not 
more than 100.degree. C., or a softening point thereof is preferably not 
more than 180.degree. C., more preferably not more than 150.degree. C. 
The term "resin capable of being removed upon a chemical reaction 
treatment" means and includes a resin which is dissolved and/or swollen 
upon a chemical reaction treatment to remove and a resin which is rendered 
hydrophilic upon a chemical reaction treatment and as a result, dissolved 
and/or swollen to remove. 
One representative example of the resin (A) capable of being removed upon a 
chemical reaction treatment used in the transfer layer according to the 
present invention is a resin which can be removed with an alkaline 
processing solution. Particularly useful resins of the resins capable of 
being removed with an alkaline processing solution include polymers 
comprising a polymer component containing a hydrophilic group. 
Another representative example of the resin (A) capable of being removed 
upon the chemical reaction treatment used in the transfer layer according 
to the present invention is a resin which has a hydrophilic group 
protected by a protective group and is capable of forming the hydrophilic 
group upon a chemical reaction. 
The chemical reaction for converting the protected hydrophilic group to a 
hydrophilic group includes a reaction for rendering hydrophilic with a 
processing solution utilizing a conventionally known reaction, for 
example, hydrolysis, hydrogenolysis, oxygenation, .beta.-release, and 
nucleophilic substitution, and a reaction for rendering hydrophilic by a 
decomposition reaction induced by exposure of actinic radiation. 
Particularly useful resins of the resins capable of being rendered 
hydrophilic upon the chemical reaction treatment includes polymers 
comprising a polymer component containing a functional group capable of 
forming a hydrophilic group. 
As the resin (A) for the formation of transfer layer, a polymer comprising 
at least one polymer component selected from a polymer component (a) 
containing a specific hydrophilic group described below and a polymer 
component (b) containing a functional group capable of forming a specific 
hydrophilic group upon a chemical reaction described below is preferred. 
Polymer component (a): 
a polymer component containing at least one group selected from a -CO.sub.2 
H group, a -CHO group, a -SO.sub.3 H group, a -SO.sub.2 H group, a 
-P(.dbd.O)(OH)R.sup.1 group (wherein R.sup.1 represents a -OH group, a 
hydrocarbon group or a -OR.sup.2 group (wherein R.sup.2 represents a 
hydrocarbon group)), a phenolic hydroxy group, a cyclic acid 
anhydride-containing group, a -CONHCOR.sup.3 group (wherein R.sup.3 
represents a hydrocarbon group) and a -CONHSO.sub.2 R.sup.3 group; Polymer 
component (b): 
a polymer component containing at least one functional group capable of 
forming at least one group selected from a -CO.sub.2 H group, a -CHO 
group, a -SO.sub.3 H group, a -SO.sub.2 H group, a -P(.dbd.O)(OH)R.sup.1 
group (wherein R.sup.1 has the same meaning as defined above) and a -OH 
group upon a chemical reaction. 
The -P(.dbd.O)(OH)R.sup.1 group denotes a group having the following 
formula: 
##STR17## 
The hydrocarbon group represented by R.sup.1, R.sup.2 or R.sup.3 preferably 
includes an aliphatic group having from 1 to 18 carbon atoms which may be 
substituted (e.g., methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, 
dodecyl, octadecyl, 2-chloroethyl, 2-methoxyethyl, 3-ethoxypropyl, allyl, 
crotonyl, butenyl, cyclohexyl, benzyl, phenethyl, 3-phenylpropyl, 
methylbenzyl, chlorobenzyl, fluorobenzyl, and methoxybenzyl) and an aryl 
group which may be substituted (e.g., phenyl, tolyl, ethylphenyl, 
propylmethylphenyl, dichlorophenyl, methoxyphenyl, cyanophenyl, 
acetamidophenyl, acetylphenyl and butoxyphenyl). 
The cyclic acid anhydride-containing group is a group containing at least 
one cyclic acid anhydride. The cyclic acid anhydride to be contained 
includes an aliphatic dicarboxylic acid anhydride and an aromatic 
dicarboxylic acid anhydride. 
Specific examples of the aliphatic dicarboxylic acid anhydrides include 
succinic anhydride ring, glutaconic anhydride ring, maleic anhydride ring, 
cyclopentane-1,2-dicarboxylic acid anhydride ring, 
cyclohexane-1,2-dicarboxylic acid anhydride ring, 
cyclohexene-1,2-dicarboxylic acid anhydride ring, and 
2,3-bicyclo[2,2,2]octanedicarboxylic acid anhydride. These rings may be 
substituted with, for example, a halogen atom (e.g., chlorine and bromine) 
and an alkyl group (e.g., methyl, ethyl, butyl, and hexyl). 
Specific examples of the aromatic dicarboxylic acid anhydrides include 
phthalic anhydride ring, naphthalenedicarboxylic acid anhydride ring, 
pyridinedicarboxylic acid anhydride ring and thiophenedicarboxylic acid 
anhydride ring. These rings may be substituted with, for example, a 
halogen atom (e.g., chlorine and bromine), an alkyl group (e.g., methyl, 
ethyl, propyl, and butyl), a hydroxyl group, a cyano group, a nitro group, 
and an alkoxycarbonyl group (e.g., methoxycarbonyl, and ethoxycarbonyl). 
To incorporate the polymer component (a) having the specific hydrophilic 
group into the thermoplastic resin used for the formation of transfer 
layer is preferred since the removal of transfer layer is easily and 
rapidly performed by a chemical reaction treatment. On the other hand, it 
is advantageous to use the thermoplastic resin contain the polymer 
component (b) which forms the specific hydrophilic group by a chemical 
reaction, because a glass transition point of the resin can be controlled 
in a low temperature range. 
By appropriately selecting the polymer component (a) and the polymer 
component (b) to be employed in the resin (A), a glass transition point of 
the resin (A) is suitably controlled and thus, transferability of the 
transfer layer is remarkably improved. Also, the transfer layer is rapidly 
and completely removed to provide a printing plate without adversely 
affecting the hydrophilic property of the non-image areas and causing 
degradation of the toner image. As a result, the image transferred on 
receiving material has excellent reproducibility, and a transfer apparatus 
of small size can be utilized since the transfer is easily conducted under 
conditions of low temperature and low pressure. Moreover, in the resulting 
printing plate, cutting of toner image in highly accurate image portions 
such as fine lines, fine letters and dots for continuous tone areas is 
prevented and the residual transfer layer is not observed. 
Suitable contents of polymer component (a) and/or polymer component (b) in 
the resin (A) are determined so as to prevent the occurrence of background 
stain in the non-image areas of prints because of incomplete removal of 
the transfer layer by a chemical reaction treatment on the one side, and 
to prevent degradation of transferability of the transfer layer onto a 
receiving material due to an excessively high glass transition point or 
softening point of the resin (A) on the other side. 
Preferred ranges of the contents of polymer component (a) and/or polymer 
component (b) in the resin (A) are as follows. 
When the resin (A) contains only the polymer component (a) having the 
specific hydrophilic group, the content of polymer component (a) is 
preferably from 3 to 50% by weight, and more preferably from 5 to 40% by 
weight based on the total polymer component in the resin (A). On the other 
hand, when the resin (A) contains only the polymer component (b) having a 
functional group capable of forming the specific hydrophilic group by a 
chemical reaction, the content of polymer component (b) is preferably from 
3 to 100% by weight, and more preferably from 5 to 70% by weight based on 
the total polymer component in the resin (A). 
Further, when the resin (A) contains both the polymer component (a) and the 
polymer component (b), the content of polymer component (a) is preferably 
from 0.5 to 30% by weight, more preferably from 1 to 25% by weight, and 
the content of polymer component (b) is preferably from 3 to 99.5% by 
weight, more preferably from 5 to 50% by weight, based on the total 
polymer component in the resin (A). 
Now, each of the polymer components which can be included in the resin (A) 
will be described in detail below. 
The polymer component (a) containing the abovedescribed specific 
hydrophilic group present in the resin (A) should not be particularly 
limited. Of the specific hydrophilic groups described above, those capable 
of forming a salt may be present in the form of salt in the polymer 
component (a). For instance, the above-described polymer component 
containing the specific hydrophilic group used in the resin (A) may be any 
of vinyl compounds each having the hydrophilic group. Such vinyl compounds 
are described, for example, in Kobunshi Data Handbook (Kiso-hen), edited 
by Kobunshi Gakkai, Baifukan (1986). Specific examples of the vinyl 
compound are acrylic acid, .alpha.- and/or .beta.-substituted acrylic acid 
(e.g., .alpha.-acetoxy compound, .alpha.-acetoxymethyl compound, 
.alpha.-(2-amino)ethyl compound, .alpha.-chloro compound, .alpha.-bromo 
compound, .alpha.-fluoro compound, .alpha.-tributylsilyl compound, 
.alpha.-cyano compound, .beta.-chloro compound, .beta.-bromo compound, 
.alpha.-chloro-.beta.-methoxy compound, and .alpha.,.beta.-dichloro 
compound), methacrylic acid, itaconic acid, itaconic acid half esters, 
itaconic acid half amides, crotonic acid, 2-alkenylcarboxylic acids (e.g., 
2-pentenoic acid, 2-methyl-2-hexenoic acid, 2-octenoic acid, 
4-methyl-2-hexenoic acid, and 4-ethyl-2-octenoic acid), maleic acid, 
maleic acid half esters, maleic acid half amides, vinylbenzenecarboxylic 
acid, vinylbenzenesulfonic acid, vinylsulfonic acid, vinylphosphonic acid, 
half ester derivatives of the vinyl group or allyl group of dicarboxylic 
acids, and ester derivatives or amide derivatives of these carboxylic 
acids or sulfonic acids having the above-described hydrophilic group in 
the substituent thereof. The hydrophilic group may be a salt thereof. 
Specific examples of the polymer components (a) containing the specific 
hydrophilic group are set forth below, but the present invention should 
not be construed as being limited thereto. In the following formulae, 
R.sup.4 represents -H or -CH.sub.3 ; R.sup.5 represents -H, -CH.sub.3 or 
-CH.sub.2 COOCH.sub.3 ; R.sup.6 represents an alkyl group having from 1 to 
4 carbon atoms; R.sup.7 represents an alkyl group having from 1 to 6 
carbon atoms, a benzyl group or a phenyl group; e represents an integer of 
1 or 2; f represents an integer of from 1 to 3; g represents an integer of 
from 2 to 11; h represents an integer of from 1 to 11; and i represents an 
integer of from 2 to 4; and j represents an integer of from 2 to 10. 
##STR18## 
The polymer component (b) containing a functional group capable of forming 
a specific hydrophilic group upon a chemical reaction will be described 
below. 
The number of hydrophilic groups formed from one functional group capable 
of forming a hydrophilic group upon the chemical reaction may be one, two 
or more. 
Now, a functional group capable of forming at least one carboxyl group upon 
a chemical reaction will be described below. 
According to one preferred embodiment of the present invention, a carboxy 
group-forming functional group is represented by the following general 
formula (F-I): 
EQU -COO-L.sup.1 (F-I) 
wherein L.sup.1 represents 
##STR19## 
wherein R.sup.11 and R.sup.12, which may be the same or different, each 
represent a hydrogen atom or a hydrocarbon group; X represents an aromatic 
group; Z represents a hydrogen atom, a halogen atom, a trihalomethyl 
group, an alkyl group, a cyano group, a nitro group, -SO.sub.2 -Z.sup.1 
(wherein Z.sup.1 represents a hydrocarbon group), -COO-Z.sup.2 (wherein 
Z.sup.2 represents a hydrocarbon group), -O-Z.sup.3 (wherein Z.sup.3 
represents a hydrocarbon group), or -CO-Z.sup.4 (wherein Z.sup.4 
represents a hydrocarbon group); n and m each represent 0, 1 or 2, 
provided that when both n and m are 0, Z is not a hydrogen atom; A.sup.1 
and A.sup.2 which may be the same or different, each represent an electron 
attracting group having a positive Hammett's .sigma. value; R.sup.13 
represents a hydrogen atom or a hydrocarbon group; R.sup.14, R.sup.15, 
R.sup.16, R.sup.20 and R.sup.21, which may be the same or different, each 
represent a hydrocarbon group or -O-Z.sup.5 (wherein Z.sup.5 represents a 
hydrocarbon group); Y.sup.1 represents an oxygen atom or a sulfur atom; 
R.sup.17, R.sup.18, and R.sup.19, which may be the same or different, each 
represent a hydrogen atom, a hydrocarbon group or -O-Z.sup.7 (wherein 
Z.sup.7 represents a hydrocarbon group); p represents an integer of 3 or 
4; Y.sup.2 represents an organic residue for forming a cyclic imido group. 
In more detail, R.sup.11 and R.sup.12, which may be the same or different, 
each preferably represents a hydrogen atom or a straight chain or branched 
chain alkyl group having from 1 to 12 carbon atoms which may be 
substituted (e.g., methyl, .ethyl, propyl, chloromethyl, dichloromethyl, 
trichloromethyl, trifluoromethyl, butyl, hexyl, octyl, decyl, 
hydroxyethyl, or 3-chloropropyl). X preferably represents a phenyl or 
naphthyl group which may be substituted (e.g., phenyl, methylphenyl, 
chlorophenyl, dimethylphenyl, chloromethylphenyl, or naphthyl). Z 
preferably represents a hydrogen atom, a halogen atom (e.g., chlorine or 
fluorine), a trihalomethyl group (e.g., trichloromethyl or 
trifluoromethyl), a straight chain or branched chain alkyl group having 
from 1 to 12 carbon atoms which may be substituted (e.g., methyl, 
chloromethyl, dichloromethyl, ethyl, propyl, butyl, hexyl, 
tetrafluoroethyl, octyl, cyanoethyl, or chloroethyl), a cyano group, a 
nitro group, -SO.sub.2 -Z.sup.1 (wherein Z.sup.1 represents an aliphatic 
group (for example an alkyl group having from 1 to 12 carbon atoms which 
may be substituted (e.g., methyl, ethyl, propyl, butyl, chloroethyl, 
pentyl, or octyl) or an aralkyl group having from 7 to 12 carbon atoms 
which may be substituted (e.g., benzyl, phenethyl, chlorobenzyl, 
methoxybenzyl, chlorophenethyl, or methylphenethyl)), or an aromatic group 
(for example, a phenyl or naphthyl group which may be substituted (e.g., 
phenyl, chlorophenyl, dichlorophenyl, methylphenyl, methoxyphenyl, 
acetylphenyl, acetamidophenyl, methoxycarbonylphenyl, or naphthyl)), 
-COO-Z.sup.2 (wherein Z.sup.2 has the same meaning as Z.sup.1 above), 
-O-Z.sup.3 (wherein Z.sup.3 has the same meaning as Z.sup.1 above), or 
-CO-Z.sup.4 (wherein Z.sup.4 has the same meaning as Z.sup.1 above). n and 
m each represent 0, 1 or 2, provided that when both n and m are 0, Z is 
not a hydrogen atom. 
R.sup.14, R.sup.15, R.sup.16, R.sup.20 and R.sup.21, which may be the same 
or different, each preferably represent an aliphatic group having 1 to 18 
carbon atoms which may be substituted (wherein the aliphatic group 
includes an alkyl group, an alkenyl group, an aralkyl group, and an 
alicyclic group, and the substituent therefor includes a halogen atom, a 
cyano group, and -O-Z.sup.6 (wherein Z.sup.6 represents an alkyl group, an 
aralkyl group, an alicyclic group, or an aryl group)), an aromatic group 
having from 6 to 18 carbon atoms which may be substituted (e.g., phenyl, 
tolyl, chlorophenyl, methoxyphenyl, acetamidophenyl, or naphthyl), or 
-O-Z.sup.5 (wherein Z.sup.5 represents an alkyl group having from 1 to 12 
carbon atoms which may be substituted, an alkenyl group having from 2 to 
12 carbon atoms which may be substituted, an aralkyl group having from 7 
to 12 carbon atoms which may be substituted, an alicyclic group having 
from 5 to 18 carbon atoms which may be substituted, or an aryl group 
having from 6 to 18 carbon atoms which may be substituted). 
A.sup.1 and A.sup.2 may be the same or different, at least one of A.sup.1 
and A.sup.2 represents an electron attracting group, with the sum of their 
Hammett's .sigma..sub.p values being 0.45 or more. Examples of the 
electron attracting group for A.sup.1 or A.sup.2 include an acyl group, an 
aroyl group, a formyl group, an alkoxycarbonyl group, a phenoxycarbonyl 
group, an alkylsulfonyl group, an aroylsulfonyl group, a nitro group, a 
cyano group, a halogen atom, a halogenated alkyl group, and a carbamoyl 
group. 
A Hammett's .sigma..sub.p value is generally used as an index for 
estimating the degree of electron attracting or donating property of a 
substituent. The greater the positive value, the higher the electron 
attracting property. Hammett's .sigma..sub.p values of various 
substituents are described, e.g., in Naoki Inamoto, Hammett Soku--Kozo to 
Han-nosei, Maruzen (1984). 
It seems that an additivity rule applies to the Hammett's .sigma..sub.p 
values in this system so that both of A.sup.1 and A.sup.2 need not be 
electron attracting groups. Therefore, where one of them is an electron 
attracting group, the other may be any group selected without particular 
limitation as far as the sum of their .sigma..sub.p values is 0.45 or 
more. 
R.sup.13 preferably represents a hydrogen atom or a hydrocarbon group 
having from 1 to 8 carbon atoms which may be substituted, e.g., methyl, 
ethyl, propyl, butyl, pentyl, hexyl, octyl, allyl, benzyl, phenethyl, 
2-hydroxyethyl, 2-methoxyethyl, 2-ethoxyethyl, 3-methoxypropyl, or 
2-chloroethyl. 
Y.sup.1 represents an oxygen atom or a sulfur atom. R.sup.17, R.sup.18, and 
R.sup.19, which may be the same or different, each preferably represents a 
hydrogen atom, a straight chain or branched chain alkyl group having from 
1 to 18 carbon atoms which may be substituted (e.g., methyl, ethyl, 
propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, octadecyl, 
chloroethyl, methoxyethyl, or methoxypropyl), an alicyclic group which may 
be substituted (e.g., cyclopentyl or cyclohexyl ) , an aralkyl group 
having from 7 to 12 carbon atoms which may be substituted (e.g., benzyl, 
phenethyl, chlorobenzyl, or methoxybenzyl), an aromatic group which may be 
substituted (e.g., phenyl, naphthyl, chlorophenyl, tolyl, methoxyphenyl, 
methoxycarbonylphenyl, or dichlorophenyl), or -O-Z.sup.7 (wherein Z.sup.7 
represents a hydrocarbon group and specifically the same hydrocarbon group 
as described for R.sup.14, R.sup.15, R.sup.16). p represents an integer of 
3 or 4. 
Y.sup.2 represents an organic residue for forming a cyclic imido group, and 
preferably represents an organic residue represented by the following 
general formula (A) or (B): 
##STR20## 
wherein R.sup.22 and R.sup.23, which may be the same or different, each 
represent a hydrogen atom, a halogen atom (e.g., chlorine or bromine), an 
alkyl group having from 1 to 18 carbon atoms which may be substituted 
(e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, 
hexadecyl, octadecyl, 2-chloroethyl, 2-methoxyethyl, 2-cyanoethyl, 
3-chloropropyl, 2-(methanesulfonyl)ethyl, or 2-(ethoxymethoxy)ethyl), an 
aralkyl group having from 7 to 12 carbon atoms which may be substituted 
(e.g., benzyl, phenethyl, 3-phenylpropyl, methylbenzyl, dimethylbenzyl, 
methoxybenzyl, chlorobenzyl, or bromobenzyl), an alkenyl group having from 
3 to 18 carbon atoms which may be substituted (e.g., allyl, 
3-methyl-2-propenyl, 2-hexenyl, 4-propyl-2-pentenyl, or 12-octadecenyl) , 
-S-Z.sup.8 (wherein Z.sup.8 represents an alkyl, aralkyl or alkenyl group 
having the same meaning as R.sup.22 or R.sup.23 described above or an aryl 
group which may be substituted (e.g., phenyl, tolyl, chlorophenyl, 
bromophenyl, methoxyphenyl, ethoxyphenyl, or ethoxycarbonylphenyl)) or 
-NH-Z.sup.9 (wherein Z.sup.9 has the same meaning as Z.sup.8 described 
above). Alternatively, R.sup.22 and R.sup.23 may be taken together to form 
a ring, such as a 5- or 6-membered monocyclic ring (e.g., cyclopentane or 
cyclohexane) or a 5- or 6-membered bicyclic ring (e.g., bicyclopentane, 
bicycloheptane, bicyclooctane, or bicyclooctene). The ring may be 
substituted. The substituent includes those described for R.sup.22 or 
R.sup.23. q represents an integer of 2 or 3. 
##STR21## 
wherein R.sup.24 and R.sup.25, which may be the same or different, each 
have the same meaning as R.sup.22 or R.sup.23 described above. 
Alternatively, R.sup.24 and R.sup.25 may be taken together to form an 
aromatic ring (e.g., benzene or naphthalene). 
According to another preferred embodiment of the present invention, the 
carboxyl group-forming functional group is a group containing an oxazolone 
ring represented by the following general formula (F-II): 
##STR22## 
wherein R.sup.26 and R.sup.27, which may be the same or different, each 
represent a hydrogen atom or a hydrocarbon group, or R.sup.26 and R.sup.27 
may be taken together to form a ring. 
In the general formula (F-II), R.sup.26 and R.sup.27 each preferably 
represents a hydrogen atom, a straight chain or branched chain alkyl group 
having from 1 to 12 carbon atoms which may be substituted (e.g., methyl, 
ethyl, propyl, butyl, hexyl, 2-chloroethyl, 2-methoxyethyl, 
2-methoxycarbonylethyl, or 3-hydroxypropyl), an aralkyl group having from 
7 to 12 carbon atoms which may be substituted (e.g., benzyl, 
4-chlorobenzyl, 4-acetamidobenzyl, phenethyl, or 4-methoxybenzyl), an 
alkenyl group having from 2 to 12 carbon atoms which may be substituted 
(e.g., vinyl, allyl, isopropenyl, butenyl, or hexenyl), a 5- to 7-membered 
alicyclic group which may be substituted (e.g., cyclopentyl, cyclohexyl, 
or chlorocyclohexyl), or an aromatic group which may be substituted (e.g., 
phenyl, chlorophenyl, methoxyphenyl, acetamidophenyl, methylphenyl, 
dichlorophenyl, nitrophenyl, naphthyl, butylphenyl, or dimethylphenyl). 
Alternatively, R.sup.26 and R.sup.27 may be taken together to form a 4- to 
7-membered ring (e.g., tetramethylene, pentamethylene, or hexamethylene). 
A functional group capable of forming at least one sulfo group upon a 
chemical reaction includes a functional group represented by the following 
general formula (F-III) or (F-IV): 
EQU -SO.sub.2 -O-L.sup.2 (F-III) 
EQU -SO.sub.2 -S-L.sup.2 (F-IV) 
wherein L.sup.2 represents 
##STR23## 
wherein R.sup.11, R.sup.12, X, Z, n, m, Y.sub.2, R.sup.20 and R.sup.21 
each has the same meaning as defined above; and R.sup.26' and R.sup.27', 
which may be the same or different, each represents a hydrogen atom or a 
hydrocarbon group, and specifically a hydrocarbon group as described for 
R.sup.26. 
A functional group capable of forming at least one sulfinic acid group upon 
a chemical reaction includes a functional group represented by the 
following general formula (F-V): 
##STR24## 
wherein A.sup.1, A.sup.2 and R.sup.13 each has the same meaning as defined 
above. 
A functional group capable of forming at least one -P(.dbd.O)(OH)R.sup.1 
group upon a chemical reaction includes a functional group represented by 
the following general formula (F-VIa) or (F-VIb): 
##STR25## 
wherein L.sup.3 and L.sup.4, which may be the same or different, each has 
the same meaning as L.sup.1 described above, and R.sup.1 has the same 
meaning as defined above. 
One preferred embodiment of functional groups capable of forming at least 
one hydroxyl group upon a chemical reaction includes a functional group 
represented by the following general formula (F-VII): 
EQU -O-L.sup.5 (F-VII) 
wherein L.sup.5 represents 
##STR26## 
wherein R.sup.14, R.sup.15, R.sup.16, R.sup.17, R.sup.18, R.sup.19, 
Y.sup.1, and p each has the same meaning as defined above; and R.sup.28 
represents a hydrocarbon group, and specifically a hydrocarbon group as 
described for R.sup.11. 
Another preferred embodiment of functional groups capable of forming at 
least one hydroxyl group upon a chemical reaction includes a functional 
group wherein at least two hydroxyl groups which are sterically close to 
each other are protected with one protective group. Such hydroxyl 
group-forming functional groups are represented, for example, by the 
following general formulae (F-VIII), (F-IX) and (F-X): 
##STR27## 
wherein R.sup.29 and R.sup.30, which may be the same or different, each 
represents a hydrogen atom, a hydrocarbon group, or -O-Z.sup.10 (wherein 
Z.sup.10 represents a hydrocarbon group); and U represents a 
carbon-to-carbon bond which may contain a hetero atom, provided that the 
number of atoms present between the two oxygen atoms is 5 or less. 
More specifically, R.sup.29 and R.sup.30, which may be the same or 
different, each preferably represents a hydrogen atom, an alkyl group 
having from 1 to 12 carbon atoms which may be substituted (e.g., methyl, 
ethyl, propyl, butyl, hexyl, 2-methoxyethyl, or octyl), an aralkyl group 
having from 7 to 9 carbon atoms which may be substituted (e.g., benzyl, 
phenethyl, methylbenzyl, methoxybenzyl, or chlorobenzyl), an alicyclic 
group having from 5 to 7 carbon atoms (e.g., cyclopentyl or cyclohexyl), 
an aryl group which may be substituted (e.g., phenyl, chlorophenyl, 
methoxyphenyl, methylphenyl, or cyanophenyl), or -OZ.sup.10 (wherein 
Z.sup.10 represents a hydrocarbon group, and specifically a hydrocarbon 
group as described for R.sup.29 or R.sup.30), and U represents a 
carbon-to-carbon bond which may contain a hetero atom, provided that the 
number of atoms present between the two oxygen atoms is 5 or less. 
Specific examples of the functional groups represented by the general 
formulae (F-I) to (F-X) described above are set forth below, but the 
present invention should not be construed as being limited thereto. In the 
following formulae (b-1) through (b-67), the symbols used have the 
following meanings respectively: 
##STR28## 
The polymer component (b) which contains the functional group capable of 
forming at least one hydrophilic group selected from -COOH, -CHO, 
-SO.sub.3 H, -SO.sub.2 H, -P(.dbd.O)(OH)R.sup.1 and -OH upon a chemical 
reaction which can be used in the present invention is not particularly 
limited. Specific examples thereof include polymer components obtained by 
protecting the hydrophilic group in the polymer components (a) described 
above. 
The above-described functional group capable of forming at least one 
hydrophilic group selected from -COOH, -CHO, -SO.sub.3 H, -SO.sub.2 H, 
-P(.dbd.O)(OH)R.sup.1, and -OH upon a chemical reaction used in the 
present invention is a functional group in which such a hydrophilic group 
is protected with a protective group. Introduction of the protective group 
into a hydrophilic group by a chemical bond can easily be carried out 
according to conventionally known methods. For example, the reactions as 
described in J. F. W. McOmie, Protective Groups in Organic Chemistry, 
Plenum Press (1973), T. W. Greene, Protective Groups in Organic Synthesis, 
Wiley-Interscience (1981), Nippon Kaghakukai (ed.), Shin Jikken Kagaku 
Koza, Vol. 14, "Yuki Kagobutsu no Gosei to Han-no", Maruzen (1978), and 
Yoshio Iwakura and Keisuke Kurita, Han-nosei Kobunshi, Kodansha can be 
employed. 
In order to introduce the functional group which can be used in the present 
invention into a resin, a process using a so-called polymer reaction in 
which a polymer containing at least one hydrophilic group selected from 
-COOH, -CHO, -SO.sub.3 H, -SO.sub.2 H, -PO.sub.3 H.sub.2, and -OH is 
reacted to convert its hydrophilic group to a protected hydrophilic group 
or a process comprising synthesizing at least one monomer containing at 
least one of the functional groups, for example, those represented by the 
general formulae (F-I) to (F-X) and then polymerizing the monomer or 
copolymerizing the monomer with any appropriate other copolymerizable 
monomer(s) is used. 
The latter process (comprising preparing the desired monomer and then 
conducting polymerization reaction) is preferred for reasons that the 
amount or kind of the functional group to be incorporated into the polymer 
can be appropriately controlled and that incorporation of impurities can 
be avoided (in case of the polymer reaction process, a catalyst to be used 
or byproducts are mixed in the polymer). 
For example, a resin containing a carboxyl group-forming functional group 
may be prepared by converting a carboxyl group of a carboxylic acid 
containing a polymerizable double bond or a halide thereof to a functional 
group represented by the general formula (F-I) by the method as described 
in the literature references cited above and then subjecting the 
functional group-containing monomer to a polymerization reaction. 
Also, a resin containing an oxazolone ring represented by the general 
formula (F-II) as a carboxyl group-forming functional group may be 
obtained by conducting a polymerization reaction of at least one monomer 
containing the oxazolone ring, if desired, in combination with other 
copolymerizable monomer(s). The monomer containing the oxazolone ring can 
be prepared by a dehydrating cyclization reaction of an 
N-acyloyl-.alpha.-amino acid containing a polymerizable unsaturated bond. 
More specifically, it can be prepared according to the method described in 
the literature references cited in Yoshio Iwakura and Keisuke Kurita, 
Han-nosei Kobunshi, Ch. 3, Kodansha. 
The resin (A) preferably contains other polymer component(s) in addition to 
the above-described specific polymer components (a) and/or (b) in order to 
maintain its thermoplasticity. As such polymer components, those which 
form a homopolymer having a glass transition point of not more than 
130.degree. C. are preferred. More specifically, examples of such other 
polymer components include those corresponding to the repeating unit 
represented by the following general formula (U): 
##STR29## 
wherein V represents -COO-, -OCO-, -O-, -CO-, -C.sub.6 H.sub.4 -, .paren 
open-st.CH.sub.2 .paren close-st..sub.n COO- or .paren open-st.CH.sub.2 
.paren close-st..sub.n OCO-; n represents an integer of from 1 to 4; 
R.sup.60 represents a hydrocarbon group having from 1 to 22 carbon atoms; 
and b.sup.1 and b.sup.2, which may be the same or different, each 
represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine 
atom, a cyano group, a trifluoromethyl group, a hydrocarbon group having 
from 1 to 7 carbon atoms (e.g., methyl, ethyl, propyl, butyl, pentyl, 
hexyl, phenyl and benzyl) or -COOZ.sup.11 (wherein Z.sup.11 represents a 
hydrocarbon group having from 1 to 7 carbon atoms). 
Preferred examples of the hydrocarbon group represented by R.sup.60 include 
an alkyl group having from 1 to 18 carbon atoms which may be substituted 
(e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, 
tridecyl, tetradecyl, 2-chloroethyl, 2-bromoethyl, 2-cyanoethyl, 
2-hydroxyethyl, 2-methoxyethyl, 2-ethoxyethyl, and 2-hydroxypropyl), an 
alkenyl group having from 2 to 18 carbon atoms which may be substituted 
(e.g., vinyl, allyl, isopropenyl, butenyl, hexenyl, heptenyl, and 
octenyl), an aralkyl group having from 7 to 12 carbon atoms which may be 
substituted (e.g., benzyl, phenethyl, naphthylmethyl, 2-naphthylethyl, 
methoxybenzyl, ethoxybenzyl, and methylbenzyl), a cycloalkyl group having 
from 5 to 8 carbon atoms which may be substituted (e.g., cyclopentyl, 
cyclohexyl, and cycloheptyl), and an aromatic group having from 6 to 12 
carbon atoms which may be substituted (e.g., phenyl, tolyl, xylyl, 
mesityl, naphthyl, methoxyphenyl, ethoxyphenyl, fluorophenyl, 
methylfluorophenyl, difluorophenyl, bromophenyl, chlorophenyl, 
dichlorophenyl, methoxycarbonylphenyl, ethoxycarbonylphenyl, 
methanesulfonylphenyl, and cyanophenyl). 
The content of one or more polymer components represented by the general 
formula (U) are preferably from 30 to 97% by weight based on the total 
polymer component in the resin (A). 
The resin (A) may contain, in addition to the polymer components (a) and/or 
(b), a polymer component (f) containing a moiety having at least one of a 
fluorine atom and a silicon atom in order to increase the releasability of 
the resin (A) itself. Using such a resin, releasability of the transfer 
layer from a primary receptor is increased and as a result, the 
transferability is improved. 
The moiety having a fluorine atom and/or a silicon atom contained in the 
resin (A) includes that incorporated into the main chain of the polymer 
and that contained as a substituent in the side chain of the polymer. 
The polymer component (f) is same as the polymer component containing a 
moiety having a fluorine atom and/or a silicon atom which is included in 
the resin (P) described in detail hereinbefore. 
The polymer components (f) are preferably present as a block in the resin 
(A). Embodiments of polymerization patterns of copolymer containing 
polymer components (f) as a block and methods for the preparation of the 
copolymer are the same as those described for the resin (P) comprising the 
fluorine atom and/or silicon atom-containing polymer components as a block 
described hereinbefore. 
The content of polymer component (f) is preferably from 1 to 20% by weight 
based on the total polymer component in the resin (A). If the content of 
polymer component (f) is less than 1% by weight, the effect for improving 
the releasability of the resin (A) is small and on the other hand, if the 
content is more than 20% by weight, wettability of the resin (A) with a 
processing solution may tend to decrease, resulting in some difficulties 
for complete removal of the transfer layer. 
Moreover, the resin (A) may further contain other copolymerizable polymer 
components than the above described specific polymer components. Examples 
of monomers corresponding to such other polymer components include, in 
addition to methacrylic acid esters, acrylic acid esters and crotonic acid 
esters containing substituents other than those described for the general 
formula (U), .alpha.-olefins, vinyl or allyl esters of carboxylic acids ( 
including, e.g. , acetic acid, propionic acid, butyric acid, valeric acid, 
benzoic acid, naphthalenecarboxylic acid, as examples of the carboxylic 
acids), acrylonitrile, methacrylonitrile, vinyl ethers, itaconic acid 
esters (e.g., dimethyl ester, and diethyl ester), acrylamides, 
methacrylamides, styrenes (e.g., styrene, vinyltoluene, chlorostyrene, 
N,N-dimethylaminomethylstyrene, methoxycarbonylstyrene, 
methanesulfonyloxystyrene, and vinylnaphthalene), vinyl sulfone compounds, 
vinyl ketone compounds, and heterocyclic vinyl compounds (e.g. , 
vinylpyrrolidone, vinylpyridine, vinylimidazole, vinylthiophene, 
vinylimidazoline, vinylpyrazoles, vinyldioxane, vinylquinoline, 
vinyltetrazole, and vinyloxazine). Such other polymer components may be 
employed in an appropriate range wherein the transferability of the resin 
(A) is not damaged. Specifically, it is preferred that the content of such 
other polymer components does not exceed 30% by weight based on the total 
polymer component of the resin (A). 
The resin (A) may be employed individually or as a combination of two or 
more thereof. 
According to a preferred embodiment of the present invention, the transfer 
layer is composed of at least two resins (A) having a glass transition 
point or a softening point different from each other. By using such a 
combination of the resins (A), transferability of the transfer layer is 
further improved. 
Specifically, the transfer layer mainly contains a resin having a glass 
transition point of from 10.degree. C. to 140.degree. C. or a softening 
point of from 35.degree. C. to 180.degree. C. (hereinafter referred to as 
resin (AH) sometimes) and a resin having a glass transition point of not 
more than 45.degree. C. or a softening point of not more than 60.degree. 
C. (hereinafter referred to as resin (AL) sometimes) in which a difference 
in the glass transition point or softening point between the resin (AH) 
and the resin (AL) is at least 2.degree. C. 
Further, the resin (AH) has a glass transition point of preferably from 
30.degree. C. to 120.degree. C., and more preferably from 35.degree. C. to 
90.degree. C., or a softening point of preferably from 38.degree. C. to 
160.degree. C., and more preferably from 40.degree. C. to 120.degree. C., 
and on the other hand, the thermoplastic resin (AL) has a glass transition 
point of preferably from -50.degree. C. to 40.degree. C., and more 
preferably from -20.degree. C. to 33.degree. C., or a softening point of 
preferably from -30.degree. C. to 45.degree. C., and more preferably from 
0.degree. C. to 40.degree. C. The difference in the glass transition point 
or softening point between the resin (AH) and the resin (AL) used is 
preferably at least 5.degree. C., and more preferably at least 10.degree. 
C. The difference in the glass transition point or softening point between 
the resin (AH) and the resin (AL) means a difference between the lowest 
glass transition point or softening point of those of the resins (AH) and 
the highest glass transition point or softening point of those of the 
resins (AL) when two or more of the resins (AH) and/or resins (AL) are 
employed. 
The resin (AH) and/or resin (AL) may contain the polymer component (f) 
described above, if desired. 
A weight ratio of the resin (AH)/the resin (AL) used in the transfer layer 
is preferably from 5/95 to 90/10, more preferably from 10/90 to 70/30. 
If desired, the transfer layer may further contain other conventional 
resins in addition to the resin (A). It should be noted, however, that 
such other resins be used in a range that the easy removal of the transfer 
layer is not deteriorated. 
Specifically, the polymer components (a) and/or (b) are preferably present 
at least 3% by weight based on the total resin used in the transfer layer. 
Examples of other resins which may be used in combination with the resin 
(A) include vinyl chloride resins, polyolefin resins, acrylic ester 
polymers or copolymers, methacrylic ester polymers or copolymers, 
styrene-acrylic ester copolymers, styrene-methacrylic ester copolymers, 
itaconic diester polymers or copolymers, maleic anhydride copolymers, 
acrylamide copolymers, methacrylamide copolymers, hydroxy group-modified 
silicone resins, polycarbonate resins, ketone resins, polyester resins, 
silicone resins, amide resins, hydroxy group- or carboxy group-modified 
polyester resins, butyral resins, polyvinyl acetal resins, cyclized 
rubber-methacrylic ester copolymers, cyclized rubber-acrylic ester 
copolymers, copolymers containing a heterocyclic ring (the heterocyclic 
ring including furan, tetrahydrofuran, thiophene, dioxane, dioxofuran, 
lactone, benzofuran, benzothiophene and 1,3-dioxethane rings), cellulose 
resins, fatty acid-modified cellulose resins, and epoxy resins. 
Further, specific examples of usable resins are described, e.g., in Plastic 
Zairyo Koza Series, Vols. 1 to 18, Nikkan Kogyo Shinbunsha (1981), Kinki 
Kagaku Kyokai Vinyl Bukai (ed.), Polyenka Vinyl, Nikkan Kogyo Shinbunsha 
(1988), Eizo Omori, Kinosei Acryl Jushi, Techno System (1985), Ei-ichiro 
Takiyama, Polyester Jushi Handbook, Nikkan Kogyo Shinbunsha (1988), Kazuo 
Yuki, Howa Polyester Jushi Handbook, Nikkan Kogyo Shinbunsha (1989), 
Kobunshi Gakkai (ed.), Kobunshi Data Handbook (Oyo-hen), Ch. 1, Baifukan 
(1986) , Yuji Harasaki (ed.), Saishin Binder Gijutsu Binran, Ch. 2, Sogo 
Gijutsu Center (1985), Taira Okuda (ed.), Kobunshi Kako, Vol. 20, 
Supplement "Nenchaku", Kobunshi Kankokai (1976), Keizi Fukuzawa, Nenchaku 
Gijutsu, Kobunshi Kankokai (1987), Mamoru Nishiguchi, Secchaku Binran, 
14th Ed., Kobunshi Kankokai (1985 ), and Nippon Secchaku Kokai (ed.), 
Secchaku Handbook, 2nd Ed., Nikkan Kogyo Shinbunsha (1980). 
These resins may be used either individually or in combination of two or 
more thereof. 
If desired, the transfer layer may contain various additives for improving 
physical characteristics, such as adhesion, film-forming property, and 
film strength. For example, rosin, petroleum resin, or silicone oil may be 
added for controlling adhesion; polybutene, DOP, DBP, low-molecular weight 
styrene resins, low molecular weight polyethylene wax, microcrystalline 
wax, or paraffin wax, as a plasticizer or a softening agent for improving 
wetting property to the light-sensitive element or decreasing melting 
viscosity; and a polymeric hindered polyvalent phenol, or a triazine 
derivative, as an antioxidant. For the details, reference can be made to 
Hiroshi Fukada, Hot-melt Secchaku no Jissai, pp. 29 to 107, Kobunshi 
Kankokai (1983). 
The transfer layer may be composed of two or more layers, if desired. In 
accordance with a preferred embodiment, the transfer layer is composed of 
a first layer which is positioned on the light-sensitive element bearing 
the toner image and which comprises a resin having a relatively high glass 
transition point or softening point, for example, one of the resins (AH) 
described above, and a second layer provided thereon comprising a resin 
having a relatively low glass transition point or softening point, for 
example, one of the resins (AL) described above, and in which the 
difference in the glass transition point or softening point therebetween 
is at least 2.degree. C. By introducing such a configuration of the 
transfer layer, transferability of the transfer layer to a primary 
receptor is remarkably improved and a further enlarged latitude of 
transfer conditions (e.g., heating temperature, pressure, and 
transportation speed) can be achieved while maintaining easy transfer to a 
final receiving material irrespective of the kind of receiving material 
which is to be converted to a printing plate. 
The transfer layer suitably has a thickness of from 0.1 to 10 .mu.m, and 
preferably from 0.5 to 7 .mu.m. When the thickness of transfer layer is at 
least 0.1 .mu.m, the transfer is sufficiently performed. In order to save 
the amount of resin to be used, the upper limit thereof is usually 10 
.mu.m. When the transfer layer is composed of a plurality of layers, a 
thickness of a single layer is at least 0.1 .mu.m while the thickness of 
the total layers is usually at most 10 .mu.m. 
According to the method of the present invention, the transfer layer is 
provided on the light-sensitive element after the formation of toner image 
on the light-sensitive element. It is preferred that the transfer layer is 
provided on the light-sensitive element bearing the toner image in an 
apparatus for performing the electrophotographic process. By the 
installation of a device of providing the transfer layer in the apparatus 
for performing the electrophotographic process, the light-sensitive 
element can be repeatedly employed after the transfer layer is released 
therefrom. Therefore, it is advantageous in that the formation and release 
of transfer layer can be performed in sequence with the 
electrophotographic process in the electrophotographic apparatus. As a 
result, a cost for the preparation of printing plate can be remarkably 
reduced. 
In order to provide the transfer layer on the light-sensitive element in 
the present invention, conventional layer-forming methods can be employed. 
For instance, a solution or dispersion containing the composition for 
transfer layer is applied onto the surface of light-sensitive element in a 
known manner. In particular, for the formation of transfer layer on the 
surface of light-sensitive element, a hot-melt coating method, an 
electrodeposition coating method or a transfer method from a releasable 
support is preferably used. These methods are preferred in view of easy 
formation of the transfer layer on the surface of light-sensitive element 
in an electrophotographic apparatus. Each of these methods will be 
described in greater detail below. 
The hot-melt coating method comprises hot-melt coating of the composition 
for the transfer layer by a known method. For such a purpose, a mechanism 
of a non-solvent type coating machine, for example, a hot-melt coating 
apparatus for a hot-melt adhesive (hot-melt coater) as described in the 
above-mentioned Hot-melt Secchaku no Jissai, pp. 197 to 215 can be 
utilized with modification to suit with coating onto the light-sensitive 
element. Suitable examples of coating machines include a direct roll 
coater, an offset gravure roll coater, a rod coater, an extrusion coater, 
a slot orifice coater, and a curtain coater. 
A melting temperature of the resin (A) at coating is usually in a range of 
from 50.degree. to 180.degree. C., while the optimum temperature is 
determined depending on the composition of the resin to be used. It is 
preferred that the resin is first molten using a closed pre-heating device 
having an automatic temperature controlling means and then heated in a 
short time to the desired temperature in a position to be coated on the 
light-sensitive element. To do so can prevent from degradation of the 
resin upon thermal oxidation and unevenness in coating. 
A coating speed may be varied depending on flowability of the resin at the 
time of being molten by heating, a kind of coater, and a coating amount, 
etc., but is suitably in a range of from 1 to 100 mm/sec, preferably from 
5 to 40 mm/sec. 
Now, the electrodeposition coating method will be described below. 
According to this method, the resin (A) is electrostatically adhered or 
electrodeposited (hereinafter simply referred to as electrodeposition 
sometimes) on the surface of light-sensitive element in the form of resin 
grains and then transformed into a uniform thin film, for example, by 
heating, thereby the transfer layer being formed. Grains of the resins (A) 
are sometimes referred to as-resin grains (AR) hereinafter. 
The resin grains must have either a positive charge or a negative charge. 
The electroscopicity of the resin grains is appropriately determined 
depending on a charging property of the light-sensitive element to be used 
in combination. 
The resin grains may contain two or more resins, if desired. For instance, 
when a combination of resins, for example, those selected from the resins 
(AH) and (AL), whose glass transition points or softening points are 
different at least 2.degree. C. from each other is used, improvement in 
transferability of the transfer layer formed therefrom to a receiving 
material and an enlarged latitude of transfer conditions can be achieved. 
The resin grains containing at least two kinds of resins therein are 
sometimes referred to as resin grains (ARW) hereinafter. In such a case, 
these resins may be present as a mixture in the grains or may form a 
layered structure such as a core/shell structure wherein a core part and, 
a shell part are composed of different resins respectively. 
An average grain diameter of the resin grains having the physical property 
described above is generally in a range of from 0.01 to 15 .mu.m, 
preferably from 0.05 to 5 .mu.m and more preferably from 0.1 to 1 .mu.m. 
The resin grains may be employed as powder grains (in case of dry type 
electrodeposition), grains dispersed in a non-aqueous system (in case of 
wet type electrodeposition), or grains dispersed in an electrically 
insulating organic substance which is solid at normal temperature but 
becomes liquid by heating (in case of pseudo-wet type electrodeposition). 
The resin grains dispersed in a non-aqueous system are preferred since 
they can easily prepare a thin layer of uniform thickness. 
The resin grains used in the present invention can be produced by a 
conventionally known mechanical powdering method or polymerization 
granulation method. These methods can be applied to the production of 
resin grains for both of dry type electrodeposition and wet type 
electrodeposition. 
The mechanical powdering method for producing powder grains used in the dry 
type electrodeposition method includes a method wherein the resin is 
directly powdered by a conventionally known pulverizer to form fine grains 
(for example, a method using a ball mill, a paint shaker or a jet mill). 
If desired, mixing, melting and kneading of the materials for resin grains 
before the powdering and classification for a purpose of controlling a 
grain diameter and after-treatment for treating the surface of grain after 
the powdering may be performed in an appropriate combination. A spray dry 
method is also employed. 
Specifically, the powder grains can be easily produced by appropriately 
using a method as described in detail, for example, in Shadanhojin Nippon 
Funtai Kogyo Gijutsu Kyokai (ed.), Zoryu Handbook, II ed., Ohm Sha (1991), 
Kanagawa Keiei Kaihatsu Center, Saishin Zoryu Gijutsu no Jissai, Kanagawa 
Keiei Kaihatsu Center Shuppan-bu (1984), and Masafumi Arakawa et al (ed.), 
Saishin Funtai no Sekkei Gijutsu, Techno System (1988). 
The polymerization granulation methods include conventionally known methods 
using an emulsion polymerization reaction, a seed polymerization reaction 
or a suspension polymerization reaction each conducted in an aqueous 
system, or using a dispersion polymerization reaction conducted in a 
non-aqueous solvent system. 
More specifically, grains are formed according to the methods as described, 
for example, in Soichi Muroi, Kobunshi Latex no Kagaku, Kobunshi Kankokai 
(1970), Taira Okuda and Hiroshi Inagaki, Gosei Jushi Emulsion, Kobunshi 
Kankokai (1978), Soichi Muroi, Kobunshi Latex Nyumon, Kobunsha (1983), I. 
Purma and P. C. Wang, Emulsion Polymerization, I. Purma and J. L. Gaudon, 
ACS Symp. Sev., 24, p. 34 (1974), Fumio Kitahara et al, Bunsan Nyukakei no 
Kagaku, Kogaku Tosho (1979), and Soichi Muroi (supervised), Chobiryushi 
Polymer no Saisentan Gijutsu, C.M.C. (1991), and then collected and 
pulverized in such a manner as described in the reference literatures 
cited with respect to the mechanical method above, thereby the resin 
grains being obtained. 
In order to conduct dry type electrodeposition of the fine powder grains 
thus-obtained, a conventionally known method, for example, a coating 
method of electrostatic powder and a developing method with a dry type 
electrostatic developing agent can be employed. More specifically, a 
method for electrodeposition of fine grains charged by a method utilizing, 
for example, corona charge, triboelectrification, induction charge, ion 
flow charge, and inverse ionization phenomenon, as described, for example, 
in J. F. Hughes, Seiden Funtai Toso, translated by Hideo Nagasaka and 
Machiko Midorikawa, or a developing method, for example, a cascade method, 
a magnetic brush method, a fur brush method, an electrostatic method, an 
induction method, a touchdown method and a powder cloud method, as 
described, for example, in Koich Nakamura (ed.), Saikin no Denshishashin 
Genzo System to Toner Zairyo no Kaihatsu.multidot.Jitsuyoka, Ch. 1, Nippon 
Kogaku Joho (1985) is appropriately employed. 
The production of resin grains dispersed in a non-aqueous system which are 
used in the wet type electrodeposition method can also be performed by any 
of the mechanical powdering method and polymerization granulation method 
as described above. 
The mechanical powdering method includes a method wherein the thermoplastic 
resin is dispersed together with a dispersion polymer in a wet type 
dispersion machine (for example, a ball mill, a paint shaker, Keddy mill, 
and Dyno-mill), and a method wherein the materials for resin grains and a 
dispersion assistant polymer (or a covering polymer) have been previously 
kneaded, the resulting mixture is pulverized and then is dispersed 
together with a dispersion polymer. Specifically, a method of producing 
paints or electrostatic developing agents can be utilized as described, 
for example, in Kenji Ueki (translated), Toryo no Ryudo to Ganryo Bunsan, 
Kyoritsu Shuppan (1971), D. H. Solomon, The Chemistry of Organic Film 
Formers, John Wiley & Sons (1967), Paint and Surface Coating Theory and 
Practice, Yuji Harasaki, Coating Kogaku, Asakura Shoten (1971), and Yuji 
Harasaki, Coating no Kiso Kagaku, Maki Shoten (1977). 
The polymerization granulation method includes a dispersion polymerization 
method in a non-aqueous system conventionally known and is specifically 
described, for example, in Chobiryushi Polymer no Saisentan Gijutsu, Ch. 
2, mentioned above, Saikin no Denshishashin Genzo System to Toner Zairyo 
no Kaihatsu.multidot.Jitsuyoka, Ch. 3, mentioned above, and K. E. J. 
Barrett, Dispersion Polymerization in Organic Media, John Wiley & Sons 
(1975). 
The resin grains (ARW) containing at least two kinds of resins having 
different glass transition points or softening points from each other 
therein described above can also be prepared easily using the seed 
polymerization method. Specifically, fine grains composed of the first 
resin are prepared by a conventionally known dispersion polymerization 
method in a non-aqueous system and then using these fine grains as seeds, 
a monomer corresponding to the second resin is supplied to conduct 
polymerization in the same manner as above. 
The resin grains (AR) composed of a random copolymer containing the polymer 
component (f) to increase the peelability of the resin (A) can be easily 
obtained by performing a polymerization reaction using one or more 
monomers forming the resin (A) which are soluble in an organic solvent but 
becomes insoluble therein by being polymerized together with a monomer 
corresponding to the polymer component (f) according to the polymerization 
granulation method described above. 
The resin grains (AR) containing the polymer component (f) as a block can 
be prepared by conducting a polymerization reaction using, as a dispersion 
stabilizing resins, a block copolymer containing the polymer component (f) 
as a block, or conducting polymerization reaction using a monofunctional 
macromonomer having a weight average molecular weight of from 
1.times.10.sup.3 to 2.times.10.sup.4, preferably from 3.times.10.sup.3 to 
1.5.times.10.sup.4 and containing the polymer component (f) as the main 
repeating unit together with one or more monomers forming the resin (A). 
Alternatively, the resin grains composed of block copolymer can be 
obtained by conducting a polymerization reaction using a polymer initiator 
(for example, azobis polymer initiator or peroxide polymer initiator) 
containing the polymer component (f) as the main repeating unit. 
As the non-aqueous solvent used in the dispersion polymerization method in 
a non-aqueous system, there can be used any of organic solvents having a 
boiling point of at most 200.degree. C., individually or in a combination 
of two or more thereof. Specific examples of the organic solvent include 
alcohols such as methanol, ethanol, propanol, butanol, fluorinated 
alcohols and benzyl alcohol, ketones such as acetone, methyl ethyl ketone, 
cyclohexanone and diethyl ketone, ethers such as diethyl ether, 
tetrahydrofuran and dioxane, carboxylic acid esters such as methyl 
acetate, ethyl acetate, butyl acetate and methyl propionate, aliphatic 
hydrocarbons containing from 6 to 14 carbon atoms such as hexane, octane, 
decane, dodecane, tridecane, cyclohexane and cyclooctane, aromatic 
hydrocarbons such as benzene, toluene, xylene and chlorobenzene, and 
halogenated hydrocarbons such as methylene chloride, dichloroethane, 
tetrachloroethane, chloroform, methylchloroform, dichloropropane and 
trichloroethane. However, the present invention should not be construed as 
being limited thereto. 
When the dispersed resin grains are synthesized by the dispersion 
polymerization method in a non-aqueous solvent system, the average grain 
diameter of the dispersed resin grains can readily be adjusted to at most 
1 .mu.m while simultaneously obtaining grains of monodisperse system with 
a very narrow distribution of grain diameters. 
A dispersive medium used for the resin grains dispersed in a non-aqueous 
system is preferably a non-aqueous solvent having an electric resistance 
of not less than 10.sup.8 .OMEGA..multidot.cm and a dielectric constant of 
not more than 3.5, since the dispersion is employed in a method wherein 
the resin grains are electrodeposited utilizing a wet type electrostatic 
photographic developing process or electrophoresis in electric fields. 
The insulating solvents which can be used include straight chain or 
branched chain aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic 
hydrocarbons, and halogen-substituted derivatives thereof. Specific 
examples of the solvent include octane, isooctane, decane, isodecane, 
decalin, nonane, dodecane, isododecane, cyclohexane, cyclooctane, 
cyclodecane, benzene, toluene, xylene, mesitylene, Isopar E, Isopar G, 
Isopar H, Isopar L (Isopar: trade name of Exxon Co.), Shellsol 70, 
Shellsol 71 (Shellsol: trade name of Shell Oil Co.), Amsco OMS and Amsco 
460 Solvent (Amsco: trade name of Americal Mineral Spirits Co.). They may 
be used singly or as a combination thereof. 
The insulating organic solvent described above is preferably employed as a 
non-aqueous solvent from the beginning of polymerization granulation of 
resin grains dispersed in the non-aqueous system. However, it is also 
possible that the granulation is performed in a solvent other than the 
above-described insulating solvent and then the dispersive medium is 
substituted with the insulating solvent to prepare the desired dispersion. 
Another method for the preparation of a dispersion of resin grains in 
non-aqueous system is that a block copolymer comprising a polymer portion 
which is soluble in the above-described non-aqueous solvent having an 
electric resistance of not less than 10.sup.8 .OMEGA..multidot.cm and a 
dielectric constant of not more than 3.5 and a polymer portion which is 
insoluble in the non-aqueous solvent, is dispersed in the non-aqueous 
solvent by a wet type dispersion method. Specifically, the block copolymer 
is first synthesized in an organic solvent which dissolves the resulting 
block copolymer according to the synthesis method of block copolymer as 
described above and then dispersed in the non-aqueous solvent described 
above. 
In order to electrodeposit dispersed grains in a dispersive medium upon 
electrophoresis, the grains must be electroscopic grains of positive 
charge or negative charge. The impartation of electroscopicity to the 
grains can be performed by appropriately utilizing techniques on 
developing agents for wet type electrostatic photography. More 
specifically, it can be carried out using electroscopic materials and 
other additives as described, for example, in Saikin no Denshishashin 
Genzo System to Toner Zairyo no Kaihatsu.multidot.Jitsuyoka, pp. 139 to 
148, mentioned above, Denshishashin Gakkai (ed.), Denshishashin Gijutsu no 
Kiso to Oyo, pp. 497 to 505, corona Sha (1988), and Yuji Harasaki, 
Denshishashin, Vol. 16, No. 2, p. 44 (1977). Further, compounds as 
described, for example, in British Patents 893,429 and 934,038, U.S. Pat. 
Nos. 1,122,397, 3,900,412 and 4,606,989, JP-A-60-179751, JP-A-60-185963 
and JP-A-2-13965 are also employed. 
The dispersion of resin grains in a non-aqueous system (latex) which can be 
employed for electrodeposition usually comprises from 0.1 to 20 g of 
grains mainly containing the resin (A), from 0.01 to 50 g of a dispersion 
stabilizing resin and if desired, from 0.0001 to 10 g of a charge control 
agent per one liter of an electrically insulating dispersive medium. 
Furthermore, if desired, other additives may be added to the dispersion of 
resin grains in order to maintain dispersion stability and charging 
stability of grains. Suitable examples of such additives include rosin, 
petroleum resins, higher alcohols, polyethers, silicone oil, paraffin wax 
and triazine derivatives. The total amount of these additives is 
restricted by the electric resistance of the dispersion. Specifically, if 
the electric resistance of the dispersion in a state of excluding the 
grains therefrom becomes lower than 10.sup.8 .OMEGA..multidot.cm, a 
sufficient amount of the resin grains deposited is reluctant to obtain 
and, hence, it is necessary to control the amounts of these additives in 
the range of not lowering the electric resistance than 10.sup.8 
.OMEGA..multidot.cm. 
The resin grains which are prepared, provided with an electrostatic charge 
and dispersed in an electrically insulting liquid behave in the same 
manner as an electrophotographic wet type developing agent. For instance, 
the resin grains can be subjected to electrophoresis on the surface of 
light-sensitive element using a developing device, for example, a slit 
development electrode device as described in Denshishashin Gijutsu no Kiso 
to Oyo, pp. 275 to 285, mentioned above. Specifically, the grains 
comprising the resin (A) are supplied between the light-sensitive element 
and an electrode placed in face of the light-sensitive element, and 
migrated by electrophoresis according to a potential gradient applied from 
an external power source to cause the grains to adhere to or 
electrodeposit on the light-sensitive element, thereby a film being 
formed. 
In general, if the charge of grains is positive, an electric voltage was 
applied between an electro-conductive support of the light-sensitive 
element and a development electrode of a developing device from an 
external power source so that the light-sensitive element is negatively 
charged, thereby the grains being electrostatically electrodeposited on 
the surface of light-sensitive element. 
Electrodeposition of grains can also be performed by wet type toner 
development in a conventional electrophotographic process. Specifically, 
the light-sensitive element is uniformly charged and then subjected to a 
conventional wet type toner development as described in Denshishashin 
Gijutsu no Kiso to Oyo, pp. 46 to 79, mentioned above. 
The medium for the resin grains dispersed therein which becomes liquid by 
heating is an electrically insulating organic compound which is solid at 
normal temperature and becomes liquid by heating at temperature of from 
30.degree. C. to 80.degree. C., preferably from 40.degree. C. to 
70.degree. C. Suitable compounds include paraffins having a solidifying 
point of from 30.degree. C. to 80.degree. C., waxes, low molecular weight 
polypropylene having a solidifying point of from 20.degree. C. to 
80.degree. C., beef tallow having a solidifying point of from 20.degree. 
C. to 50.degree. C. and hardened oils having a solidifying point of from 
30.degree. C. to 80.degree. C. They may be employed individually or as a 
combination of two or more thereof. 
Other characteristics required are same as those for the dispersion of 
resin grains used in the wet type developing method. 
The resin grains used in the pseudo-wet type electrodeposition according to 
the present invention can stably maintain their state of dispersion 
without the occurrence of heat adhesion of dispersed resin grains by 
forming a core/shell structure wherein the core portion is composed of a 
resin having a lower glass transition point or softening point and the 
shell portion is composed of a resin having a higher glass transition 
point or softening point which is not softened at the temperature at which 
the medium used becomes liquid. 
The amount of resin grain adhered to the light-sensitive element can be 
appropriately controlled, for example, by modifying an external bias 
voltage applied, a potential of the light-sensitive element charged and a 
processing time. 
After the electrodeposition of grains, the liquid is wiped off upon squeeze 
using a rubber roller, a gap roller or a reverse roller. Other known 
methods, for example, corona squeeze and air squeeze can also be employed. 
Then, the deposit is dried with cool air or warm air or by a infrared lamp 
preferably to be rendered the resin grains in the form of a film, thereby 
the transfer layer being formed. 
The electrodeposition coating method is particularly preferred since a 
device used therefor is simple and compact and a uniform layer of a small 
thickness can be stably and easily prepared. 
Now, the formation of transfer layer by the transfer method from a 
releasable support will be described below. According to this method, the 
transfer layer provided on a releasable support typically represented by 
release paper (hereinafter simply referred to as release paper) is 
transferred onto the surface of light-sensitive element. 
The release paper having the transfer layer thereon is simply supplied to a 
transfer device in the form of a roll or sheet. 
The release paper which can be employed in the present invention include 
those conventionally known as described, for example, in Nenchaku 
(Nensecchaku) no Shin Gijutsu to Sono Yoto-Kakushu Oyoseihin no Kaihatsu 
Siryo, published by Keiei Kaihatsu Center Shuppan-bu (May 20, 1978), and 
All Paper Guide Shi no Shohin Jiten, Jo Kan, Bunka Sangyo Hen, published 
by Shigyo Times Sha (Dec. 1, 1983). 
Specifically, the release paper comprises a substrate such as nature Clupak 
paper laminated with a polyethylene resin, high quality paper pre-coated 
with a solvent-resistant resin, kraft paper, a PET film having an 
under-coating or glassine having coated thereon a release agent mainly 
composed of silicone. 
A solvent type of silicone is usually employed and a solution thereof 
having a concentration of from 3 to 7% by weight is coated on the 
substrate, for example, by a gravure roll, a reverse roll or a wire bar, 
dried and then subjected to heat treatment at not less than 150.degree. C. 
to be cured. The coating amount is usually about 1 g/m.sup.2. 
Release paper for tapes, labels, formation industry use and cast coat 
industry use each manufactured by a paper making company and put on sale 
are also generally employed. Specific examples thereof include Separate 
Shi (manufactured by Oji Paper Co., Ltd.), King Rease (manufactured by 
Shikoku Seishi K.K.), San Release (manufactured by Sanyo Kokusaku Pulp 
K.K.) and NK High Release (manufactured by Nippon Kako Seishi K.K.). 
In order to form the transfer layer on release paper, a composition for the 
transfer layer mainly composed of the resin (A) is applied to releasing 
paper in a conventional manner, for example, by bar coating, spin coating 
or spray coating to form a film. The transfer layer may also be formed on 
release paper by a hot-melt coating method or an electrodeposition coating 
method. 
For a purpose of heat transfer of the transfer layer on release paper to 
the light-sensitive element having the toner image, conventional heat 
transfer methods are utilized. Specifically, release paper having the 
transfer layer thereon is pressed on the light-sensitive element bearing 
the toner image to heat transfer the transfer layer. For instance, a 
device shown in FIG. 4 is employed for such a purpose. 
The conditions for transfer of the transfer layer from release paper to the 
surface of light-sensitive element bearing the toner image are preferably 
as follows. A nip pressure of the roller is from 0.1 to 10 kgf/cm.sup.2 
and more preferably from 0.2 to 8 kgf/cm.sup.2. A temperature at the 
transfer is from 25.degree. to 100.degree. C. and more preferably from 
40.degree. to 80.degree. C. A speed of the transportation is from 0.5 to 
300 mm/sec and more preferably from 3 to 200 mm/sec. The speed of 
transportation may differ from that of the electrophotographic step, or 
that of the heat transfer step of the transfer layer to a primary 
receptor. 
According to the method of the present invention, after the formation of 
transfer layer on the light-sensitive element bearing the toner image, the 
transfer layer is heat-transferred onto a primary receptor. 
The heat-transfer of the toner image together with the transfer layer onto 
a primary receptor can be performed using known methods and devices. For 
instance, the light-sensitive element having the toner image and the 
transfer layer provided thereon is brought into intimate contact with a 
primary receptor and they are passed between rollers under pressure and 
the toner image is transferred together with the transfer layer onto a 
primary receptor. 
The surface temperature of transfer layer at the time of heat transfer is 
preferably in a range of from 30.degree. to 150.degree. C., and more 
preferably from 35.degree. to 90.degree. C. A non-contact type heater such 
as an infrared line heater or a flash heater is employed in order to heat 
the transfer layer into the desired temperature range, if desired. 
The nip pressure of rollers is preferably in a range of from 0.2 to 20 
kgf/cm.sup.2 and more preferably from 0.5 to 15 kgf/cm.sup.2. The rollers 
may be pressed by springs provided on opposite ends of the roller shaft or 
by an air cylinder using compressed air. A speed of the transportation is 
preferably in a range of from 0.1 to 300 mm/sec and more preferably in a 
range of from 1 to 200 mm/sec. The speed of transportation may differ 
between the electrophotographic process and the heat transfer step. 
Now, the primary receptor which can be used in the present invention will 
be described in detail below. It is important that releasability of the 
surface of primary receptor is less than releasability of the surface of 
light-sensitive element but is sufficient for peeling and transferring 
onto a receiving material. Specifically, the surface of primary receptor 
has the adhesive strength larger, preferably 10 g.multidot.f larger, more 
preferably 30 g.multidot.f larger, than the adhesive strength of the 
surface of light-sensitive element. On the other hand, the adhesive 
strength of the surface of primary receptor is preferably at most 250 
g.multidot.f, more preferably at most 180 g.multidot.f. 
Any type of primary receptor can be employed as far as the above described 
conditions are fulfilled. For example, primary receptors of a drum type 
and an endless belt type which are repeatedly usable are preferred in the 
present invention. Also, any material can be employed for the primary 
receptor as far as the conditions described above are fulfilled. In the 
primary receptor of drum type or endless belt type, an elastic material 
layer or a stratified structure of an elastic material layer and a 
reinforcing layer is preferably provided on the surface thereof 
stationarily or removably so as to be replaced. 
Any of conventionally known natural resins and synthetic reins can be used 
as the elastic material. These resins may be used either individually or 
as a combination of two or more thereof in a single or plural layer. 
Specifically, various resins described, for example, in A. D. Roberts, 
Natural Rubber Science and Technology, Oxford Science Publications (1988), 
W. Hofmann, Rubber Technology Handbook, Hanser Publisher (1989) and 
Plastic Zairyo Koza, Vols. 1 to 18, Nikkan Kogyo Shinbunsha can be 
employed. 
Specific examples of the elastic material include styrene-butadiene rubber, 
butadiene rubber, acrylonitrile-butadiene rubber, cyclized rubber, 
chloroprene rubber, ethylene-propylene rubber, butyl rubber, 
chloro-sulfonated polyethylene rubber, silicone rubber, fluoro-rubber, 
polysulfide rubber, natural rubber, isoprene rubber and -urethane rubber. 
The desired elastic material can be appropriately selected by taking 
releasability from the transfer layer, durability, etc. into 
consideration. The thickness of elastic material layer is preferably from 
0.01 to 10 mm. 
Examples of materials used in the reinforcing layer for the elastic 
material layer include cloth, glass fiber, resin-impregnated specialty 
paper, aluminum and stainless steel. A spongy rubber layer may be provided 
between the surface elastic material layer and the reinforcing layer. 
Conventionally known materials can be used as materials for the primary 
receptor of endless belt type. For example, those described in U.S. Pat. 
Nos. 3,893,761, 4,684,238 and 4,690,539 are employed. Further, a layer 
serving as a heating medium may be provided in the belt as described in 
JP-W-4-503265 (the term "JP-W" as used herein means an "unexamined 
published international patent application"). 
The adhesive strength of the surface of primary receptor can be easily 
adjusted by applying the method as described with respect to the 
releasability of the surface of light-sensitive element hereinbefore, 
including the application of the compound (S). The surface of primary 
receptor has preferably an average roughness of 0.01 mm or below. 
The transfer layer bearing the toner image on the primary receptor is then 
heat-transferred onto a receiving material. 
The receiving material used in the present invention is any of material 
which provide a hydrophilic surface suitable for lithographic printing. 
Supports conventionally used for offset printing plates (lithographic 
printing plates) can be preferably employed. Specific examples of support 
include a substrate having a hydrophilic surface, for example, a plastic 
sheet, paper having been rendered durable to printing, an aluminum plate, 
a Zinc plate, a bimetal plate, e.g., a copper-aluminum plate, a 
copper-stainless steel plate, or a chromium-copper plate, a trimetal 
plate, e.g., a chromium-copper-aluminum plate, a chromium-lead-iron plate, 
or a chromium-copper-stainless steel plate. The support preferably has a 
thickness of from 0.1 to 3 mm, and particularly from 0.1 to 1 mm. 
A support with an aluminum surface is preferably subjected to a surface 
treatment, for example, surface graining, immersion in an aqueous solution 
of sodium silicate, potassium fluorozirconate or a phosphate, or 
anodizing. Also, an aluminum plate subjected to surface graining and then 
immersion in a sodium silicate aqueous solution as described in U.S. Pat. 
No. 2,714,066, or an aluminum plate subjected to anodizing and then 
immersion in an alkali silicate aqueous solution as described in 
JP-B-47-5125 is preferably employed. 
Anodizing of an aluminum surface can be carried out by electrolysis of an 
electrolytic solution comprising at least one aqueous or nonaqueous 
solution of an inorganic acid (e.g., phosphoric acid, chromic acid, 
sulfuric acid or boric acid) or an organic acid (e.g., oxalic acid or 
sulfamic acid) or a salt thereof to oxidize the aluminum surface as an 
anode. 
Silicate electrodeposition as described in U.S. Pat. No. 3,658,662 or a 
treatment with polyvinylsulfonic acid described in West German Patent 
Application (OLS) 1,621,478 is also effective. 
The surface treatment is conducted not only for rendering the surface of a 
support hydrophilic, but also for improving adhesion of the support to the 
transferred toner image. 
Further, in order to control an adhesion property between the support and 
the transfer layer having provided thereon the toner image, a surface 
layer may be provided on the surface of the support. 
A plastic sheet or paper as the support should have a hydrophilic surface 
layer, as a matter of course, since its areas other than those 
corresponding to the toner images must be hydrophilic. Specifically, a 
receiving material having the same performance as a known direct writing 
type lithographic printing plate precursor or an image-receptive layer 
thereof may be employed. 
The heat-transfer of the toner image together with the transfer layer onto 
a receiving material can be performed using known methods and apparatus. 
Preferred ranges of temperature, nip pressure and transportation speed for 
the heat-transfer of transfer layer bearing the toner image from the 
primary receptor onto the receiving material are same as those described 
for the heat transfer step of toner image to the primary receptor 
respectively. Further, the specific conditions of transfer onto the 
receiving material may be the same as or different from those of transfer 
of toner image to the primary receptor. 
The heat-transfer behavior of transfer layer onto the receiving material is 
considered as follows. Specifically, when the transfer layer softened to a 
certain extent, for example, by a pre-heating means is further heated, for 
example, a heating roller, the tackiness of the transfer layer increases 
and the transfer layer is closely adhered to the receiving material. 
After the transfer layer is passed under a roller for release, for example, 
a cooling roller, the temperature of the transfer layer is decreased to 
reduce the flowability and the tackiness and thus the transfer layer is 
peeled as a film from the surface of the primary receptor together with 
the toner thereon. Accordingly, the transfer conditions should be set so 
as to realize such a situation. 
The cooling roller comprises a metal roller which has a good thermal 
conductivity such as aluminum, copper or the like and is covered with 
silicone rubber. It is preferred that the cooling roller is provided with 
a cooling means therein or on a portion of the outer surface which is not 
brought into contact with the receiving material in order to radiate heat. 
The cooling means includes a cooling fan, a coolant circulation or a 
thermoelectric cooling element, and it is preferred that the cooling means 
is coupled with a temperature controller so that the temperature of the 
cooling roller is maintained within a predetermined range. 
In the method of the present invention, the transfer of toner image 
together with the transfer layer from the light-sensitive element to the 
primary receptor and the transfer of toner image together with the 
transfer layer from the primary receptor to the receiving material may be 
simultaneously performed within one sheet. Alternatively, after the 
transfer of all of one sheet from the light-sensitive element to the 
primary receptor is completed, the image is transferred to the receiving 
material. 
It is needless to say that the above-described conditions for the transfer 
of toner image and transfer layer should be optimized depending on the 
physical properties of the light-sensitive element (i.e., the 
light-sensitive layer and the support), the transfer layer, the primary 
receptor, and the receiving material. Especially it is important to 
determine the conditions of temperature, in the heat transfer step taking 
into account the factors such as glass transition point, softening 
temperature, flowability, tackiness, film properties and film thickness of 
the transfer layer. 
Now, the step of subjecting the receiving material having the transfer 
layer transferred thereon (printing plate precursor) with a chemical 
reaction treatment to remove the transfer layer, thereby providing a 
printing plate will be described below. In order to remove the transfer 
layer, an appropriate means can be selected in consideration of a chemical 
reaction treatment upon which a resin used in the transfer layer is 
removed. For instance, treatment with a processing solution, treatment 
with irradiation of actinic ray or a combination thereof can be employed 
for removal of the transfer layer. 
In order to effect the removal by a chemical reaction with a processing 
solution, an aqueous solution which is adjusted to the prescribed pH is 
used. Known pH control agents can be employed to adjust the pH of 
solution. While the pH of the processing solution used may be any of 
acidic, neutral and alkaline region, the processing solution is preferably 
employed in an alkaline region having a pH of 8 or higher taking account 
of an anticorrosive property and a property of dissolving the transfer 
layer. The alkaline processing solution can be prepared by using any of 
conventionally known organic or inorganic compounds, such as carbonates, 
sodium hydroxide, potassium hydroxide, potassium silicate, sodium 
silicate, and organic amine compounds, either individually or in 
combination thereof. 
The processing solution may contain a hydrophilic compound which contains a 
substituent having a Pearson's nucleophilic constant n (refer to R. G. 
Pearson and H. Sobel, J. Amer. Chem. Soc., Vol. 90, p. 319 (1968)) of not 
less than 5.5 and has a solubility of at least 1 part by weight in 100 
parts by weight of distilled water, in order to accelerate the reaction 
for rendering hydrophilic. 
Suitable examples of such hydrophilic compounds include hydrazines, 
hydroxylamines, sulfites (e.g., ammonium sulfite, sodium sulfite, 
potassium sulfite or zinc sulfite), thiosulfates, and mercapto compounds, 
hydrazide compounds, sulfinic acid compounds and primary or secondary 
amine compounds each containing at least one polar group selected from a 
hydroxyl group, a carboxyl group, a sulfo group, a phosphono group and an 
amino group in the molecule thereof. 
Specific examples of the polar group-containing mercapto compounds include 
2-mercaptoethanol, 2-mercaptoethylamine, N-methyl-2-mercaptoethylamine, 
N-(2-hydroxyethyl)-2-mercaptoethylamine, thioglycolic acid, thiomalic 
acid, thiosalicylic acid, mercaptobenzenecarboxylic acid, 
2-mercaptotoluensulfonic acid, 2-mercaptoethylphosphonic acid, 
mercaptobenzenesulfonic acid, 2-mercaptopropionylaminoacetic acid, 
2-mercapto-1-aminoacetic acid, 1-mercaptopropionylaminoacetic acid, 
1,2-dimercaptopropionylaminoacetic acid, 2,3-dihydroxypropylmercaptan, and 
2-methyl-2-mercapto-1-aminoacetic acid. Specific examples of the polar 
group-containing sulfinic acid compounds include 2-hydroxyethylsulfinic 
acid, 3-hydroxypropanesulfinic acid, 4-hydroxybutanesulfinic acid, 
carboxybenzenesulfinic acid, and dicarboxybenzenesulfinic acid. Specific 
examples of the polar group-containing hydrazide compounds include 
2-hydrazinoethanolsulfonic acid, 4-hydrazinobutanesulfonic acid, 
hydrazinobenzenesulfonic acid, hydrazinobenzenesulfonic acid, 
hydrazinobenzoic acid, and hydrazinobenzenecarboxylic acid. Specific 
examples of the polar group-containing primary or secondary amine 
compounds include N-(2-hydroxyethyl)amine, N,N-di(2-hydroxyethyl)amine, 
N,N-di(2-hydroxyethyl)ethylenediamine, 
tri-(2-hydroxyethyl)ethylenediamine, N-(2,3-dihydroxypropyl)amine, 
N,N-di(2,3-dihydroxypropyl)amine, 2-aminopropionic acid, aminobenzoic 
acid, aminopyridine, aminobenzenedicarboxylic acid, 
2-hydroxyethylmorpholine, 2-carboxyethylmorpholine, and 
3-carboxypiperazine. 
The amount of the nucleophilic compound present in the processing solution 
is preferably from 0.05 to 10 mol/l, and more preferably from 0.1 to 5 
mol/l. The pH of the processing solution is preferably not less than 8. 
The processing solution may contain other compounds in addition to the pH 
control agent and nucleophilic compound described above. For example, an 
organic solvent soluble in water may be used in a range of from about 1 to 
about 50 parts by weight per 100 parts by weight of water. Suitable 
examples of the water-soluble organic solvent include alcohols (e.g., 
methanol, ethanol, propanol, propargyl alcohol, benzyl alcohol, and 
phenethyl alcohol), ketones (e.g., acetone, methyl ethyl ketone, 
cyclohexanone and acetophenone), ethers (e.g., dioxane, trioxane, 
tetrahydrofuran, ethylene glycol dimethyl ether, propylene glycol diethyl 
ether, ethylene glycol monomethyl ether, propylene glycol monomethyl 
ether, and tetrahydropyran), amides (e.g., dimethylformamide, pyrrolidone, 
N-methylpyrrolidone, and dimethylacetamide), esters (e.g., methyl acetate, 
ethyl acetate, and ethyl formate), sulforan and tetramethylurea. These 
organic solvents may be used either individually or in combination of two 
or more thereof. 
The processing solution may contain a surface active agent in an amount 
ranging from about 0.1 to about 20 parts by weight per 100 parts by weight 
of water. Suitable examples of the surface active agent include 
conventionally known anionic, cationic or nonionic surface active agents, 
such as the compounds as described, for example, in Hiroshi Horiguchi, 
Shin Kaimen Kasseizai, Sankyo Shuppan (1975) and Ryohei Oda and Kazuhiro 
Teramura, Kaimen Kasseizai no Gosei to Sono Oyo, Maki Shoten (1980). 
Moreover, conventionally known antiseptic compounds and antimoldy 
compounds are employed in appropriate amounts in order to improve the 
antiseptic property and antimoldy property of the processing solution 
during preservation. 
With respect to the conditions of the treatment, a temperature of from 
about 15.degree. to about 60.degree. C., and an immersion time of from 
about 10 seconds to about 5 minutes are preferred. 
The treatment with the processing solution may be combined with a physical 
operation, for example, application of ultrasonic wave or mechanical 
movement (such as rubbing with a brush). 
Actinic ray which can be used for decomposition to render the transfer 
layer hydrophilic upon the irradiation treatment includes any of visible 
light, ultraviolet light, far ultraviolet light, electron beam, X-ray, 
.gamma.-ray, and .alpha.-ray, with ultraviolet light being preferred. More 
preferably rays having a wavelength range of from 310 to 500 nm are used. 
As a light source, a high-pressure or ultrahigh-pressure mercury lamp is 
ordinarily utilized. Usually, the irradiation treatment can be 
sufficiently carried out from a distance of from 5 to 50 cm for a period 
of from 10 seconds to 10 minutes. The thus irradiated transfer layer is 
then soaked in an aqueous solution whereby the transfer layer is easily 
removed. 
Now, the method for preparation of a printing plate using an 
electrophotographic process according to the present invention will be 
described in more detail with reference to the accompanying drawings 
hereinbelow. 
FIG. 2 is a schematic view of an apparatus for preparation of a printing 
plate precursor by an electrophotographic process suitable for conducting 
the method according to the present invention wherein a primary receptor 
20 of a drum type is employed. 
As described above, when electrophotographic light-sensitive element 11 
whose surface has been modified to have releasability, a toner image is 
formed on light-sensitive element 11 by a conventional electrophotographic 
process. On the other hand, when releasability of the surface of 
light-sensitive element 11 is insufficient, the compound (S) is applied to 
the surface of light-sensitive element before the start of 
electrophotographic process thereby the desired releasability being 
imparted to the surface of light-sensitive element 11. Specifically, the 
compound (S) is supplied from a device for applying compound (S) 10 which 
utilizes any one of the embodiments as described above onto the surface of 
light-sensitive element 11. The device for applying compound (S) 10 may be 
stationary or movable. 
The light-sensitive element whose surface has the releasability is then 
subjected to the electrophotographic process. While a dry developer can be 
utilized in the development step according to the present invention as 
described above, a wet type developing method is employed in the following 
embodiment since duplicated image having high definition can be obtained. 
The light-sensitive element is uniformly charged to, for instance, a 
positive polarity by a corona charger 18 and then is exposed imagewise by 
an exposure device (e.g., a semi-conductor laser) 19 on the basis of image 
information, whereby the potential is lowered in the exposed regions and 
thus, a contrast in potential is formed between the exposed regions and 
the unexposed regions. A liquid developing unit 14L containing a liquid 
developer comprising resin grains having a positive electrostatic charge 
dispersed in an electrically insulating liquid is brought near the surface 
of a light-sensitive element 11 from a liquid developing unit set 14 and 
is kept stationary with a gap of 1 mm therebetween. 
The light-sensitive element 11 is first prebathed by a pre-bathing means 
provided in the liquid developing unit, and then the liquid developer is 
supplied on the surface of the light-sensitive element while applying a 
developing bias voltage between the light-sensitive element and a 
development electrode by a bias voltage source and wiring (not shown). The 
bias voltage is applied so that it is slightly lower than the surface 
potential of the unexposed regions, while the development electrode is 
charged to positive and the light-sensitive element is charged to 
negative. When the bias voltage applied is too low, a sufficient density 
of the toner image cannot be obtained. 
The liquid developer adhering to the surface of light-sensitive element is 
subsequently washed off by a rinsing means 14R provided in the liquid 
developing unit set 14 and the rinse solution adhering to the surface of 
light-sensitive element is removed by a squeeze means. Then, the 
light-sensitive element is dried by passing under a suction/exhaust unit 
15. Meanwhile a primary receptor 20 is kept away from the surface of 
light-sensitive element. 
On the light-sensitive element 11 bearing the toner image thus-formed is 
now provided a transfer layer by a device for providing transfer layer 13. 
In this embodiment, the transfer layer is formed by the electrodeposition 
coating method. An electrodeposition unit containing a dispersion of resin 
grains is first brought near the surface of light-sensitive element and is 
kept stationary with a gap of 1 mm between the surface thereof and a 
development electrode of the electrodeposition unit. The light-sensitive 
element is rotated while supplying the dispersion of resin grains into the 
gap and applying an electric voltage across the gap from an external power 
source (not shown), whereby the grains are deposited over the entire areas 
of the surface of the light-sensitive element bearing the toner image. 
The dispersion of resin grains adhering to the surface of the 
light-sensitive element is removed by a squeezing device built in the 
electrodeposition unit 13. Then the resin grains are fused by a heating 
means and thus a transfer layer in the form of resin film is obtained. 
In order to conduct the exhaustion of solvent in the dispersion, the 
suction/exhaust unit 15 provided for an electrophotographic process of the 
electrophotographic light-sensitive element may be employed. As the 
pre-bathing solution and the rinse solution, a carrier liquid for the 
liquid developer is ordinarily used. While the electrodeposition unit is 
provided independently as the device for providing transfer layer as shown 
in FIG. 2, it may be built in the liquid developing unit set 14 as 14T 
shown in FIG. 3. 
After the transfer layer is formed on the light-sensitive element, the 
transfer layer is pre-heated in the desired range of temperature by a 
pre-heating means 16, if desired, the primary receptor 20 is also 
pre-heated in the desired range of temperature, and then the transfer 
layer is brought into close contact with the primary receptor, whereby the 
toner image is heat-transferred together with the transfer layer onto the 
primary receptor 20. 
The toner image transferred together with the transfer layer 12 on the 
primary receptor 20 is then heat-transferred onto a receiving material 30 
together with the transfer layer 20. Specifically, the primary receptor 20 
is pre-heated in the desired range of temperature by a pre-heating means 
16, a receiving material 30 is also pre-heated in the desired range of 
temperature by a back-up roller for transfer 31, the primary receptor 20 
bearing the toner image is brought into close contact with the receiving 
material 30 and then the receiving material 30 is cooled by a back-up 
roller for release 32, thereby heat-transferring the toner image to the 
receiving material together with the transfer layer. Thus a cycle of steps 
is terminated. 
In the event of imparting the desired releasability onto the surface of 
light-sensitive element, by stopping the apparatus in the stage where the 
compound (S) has been applied thereon by the device for applying compound 
(S) 10, the next operation can start with the electrophotographic process. 
FIG. 3 is a schematic view of another example of apparatus for preparation 
of a printing plate precursor according to the present invention wherein a 
primary receptor 20 of an endless belt type is employed. In the apparatus 
of FIG. 3, its construction is essentially similar to that of the 
apparatus shown in FIG. 2. 
Further, in order to provide the transfer layer on the light-sensitive 
element bearing the toner image, a device utilizing the hot-melt coating 
method or a device utilizing the transfer method from a release support 
can be used in place of the device utilizing the electrodeposition coating 
method described above as the device for providing transfer layer 13. 
In case of using the hot-melt coating method, the resin (A) is coated on 
the surface of light-sensitive element provided on the peripheral surface 
of a drum by a hot-melt coater and is caused to pass under a 
suction/exhaust unit to be cooled to a predetermined temperature to form 
the transfer layer. Thereafter, the hot-melt coater is moved to a stand-by 
position. 
A device for forming a transfer layer on the light-sensitive element using 
release paper is schematically shown in FIG. 4. In FIG. 4, release paper 
24 having thereon the transfer layer 12 is heat-pressed on the 
light-sensitive element 11 bearing the toner image by a heating roller 
25b, thereby the transfer layer 12 being transferred on the surface of 
light-sensitive element 11. The release paper 24 is cooled by a cooling 
roller 25c and recovered. The light-sensitive element is heated by a 
pre-heating means 25a to improve transferability of the transfer layer 12 
upon heat-press, if desired. 
A providing part of transfer layer 120 in FIG. 4 is first employed to 
transfer a transfer layer 12 from release paper 24 to a light-sensitive 
element 11 and then used for transfer of the transfer layer to a receiving 
material as a transferring part to receiving material 130 shown in FIG. 2 
or 3. Alternatively, both the providing part of transfer layer 120 for 
transfer the transfer layer 12 from release paper 24 to the 
light-sensitive element 11 and the transferring part to receiving material 
130 for transfer the toner image together with the transfer layer to the 
receiving material are installed in the apparatus according to the present 
invention. 
When the transfer layer of integrated layered type is employed in the 
present invention, it can be formed using two or more transfer 
layer-forming devices which may be the same or different from each other. 
In accordance with the present invention, a printing plate which provides 
images of high accuracy and high quality can be obtained in a simple 
manner by conducting electrophotographic development to form a toner image 
on an electrophotographic light-sensitive element having the surface of 
releasability, providing a transfer layer on the light-sensitive element 
bearing the toner image, transferring the toner image together with the 
transfer layer onto a primary receptor and then onto a receiving material, 
and being subjected to oil-desensitization to remove the transfer layer. 
Further, an enlarged latitude of the heat-transfer (for example, decrease 
in pressure and/or temperature for the transfer, and increase in a 
transfer speed) and moderation of the condition of oil-desensitizing 
treatment can be achieved. 
Moreover, a conventional electrophotographic light-sensitive element can be 
employed in the method of the present invention by imparting the desired 
releasability on the surface thereof using the compound (s). 
The present invention is illustrated in greater detail with reference to 
the following examples, but the present invention is not to be construed 
as being limited thereto. 
Synthesis Examples of Resin Grain (AR): 
SYNTHESIS EXAMPLE 1 OF RESIN GRAIN (AR): (AR-1) 
A mixed solution of 16 g of Dispersion Stabilizing Resin (Q-1) having the 
structure shown below and 550 g of Isopar H was heated to a temperature of 
50.degree. C. under nitrogen gas stream while stirring. 
##STR30## 
To the solution was dropwise added a mixed solution of 85.0 g of benzyl 
methacrylate, 15.0 g of acrylic acid, 2.0 g of methyl 
3-mercaptopropionate, 1.2 g of 2,2'-azobis(2-cyclopropylpropionitrile) 
(abbreviated as ACPP) and 200 g of Isopar H over a period of one hour, 
followed by stirring for one hour. To the reaction mixture was added 0.8 g 
of ACPP, followed by reacting for 2 hours. Further, 0.5 g of 
2,2'-azobis(isobutyronitrile) (abbreviated as AIBN) was added thereto, the 
reaction temperature was adjusted to 80.degree. C., and the reaction was 
continued for 3 hours. After cooling, the reaction mixture was passed 
through a nylon cloth of 200 mesh to obtain a white dispersion which was a 
latex of good monodispersity with a polymerization ratio of 97% and an 
average grain diameter of 0.17 .mu.m. The grain diameter was measured by 
CAPA-500 manufactured by Horiba Ltd. (hereinafter the same). 
A part of the white dispersion was centrifuged at a rotation of 
1.times.10.sup.4 r.p.m. for one hour and the resin grains precipitated 
were collected and dried. A weight average molecular weight (Mw) of the 
resin grain measured by a GPC method and calculated in terms of 
polystyrene (hereinafter the same) was 9.8.times.10.sup.4. A glass 
transition point (Tg) thereof was 65.degree. C. 
SYNTHESIS EXAMPLE 2 OF RESIN GRAIN (AR): (AR-2) 
A mixed solution of 14 g of Dispersion Stabilizing Resin (Q-2) having the 
structure shown below, 10 g of Macromonomer (M-1) having the structure 
shown below, and 553 g of Isopar H was heated to a temperature of 
55.degree. C. under nitrogen gas stream while stirring. 
##STR31## 
To the solution was added dropwise a mixed solution of 51.2 g of methyl 
methacrylate, 30 g of methyl acrylate, 12.5 g of acrylic acid, 1.3 g of 
methyl 3-mercaptopropionate, 1.2 g of ACPP and 200 g of Isopar H over a 
period of one hour, followed by reacting for one hour. Then, 0.8 g of 
2,2'-azobis(isovaleronitrile) (abbreviated as AIVN) was added thereto and 
the temperature was immediately adjusted to 75.degree. C., and the 
reaction was continued for 2 hours. To the reaction mixture was further 
added 0.5 g of AIVN, followed by reacting for 2 hours. After cooling, the 
reaction mixture was passed through a nylon cloth of 200 mesh to obtain a 
white dispersion which was a latex of good monodispersity with a 
polymerization ratio of 98% and an average grain diameter of 0.18 .mu.m. 
An Mw of the resin grain was 2.times.10.sup.4 and a Tg thereof was 
50.degree. C. 
SYNTHESIS EXAMPLES 3 TO 11 OF RESIN GRAIN (AR): (AR-3) TO (AR-11) 
A mixed solution of 20 g of Dispersion Stabilizing Resin (Q-3) having the 
structure shown below and 480 g of Isopar G was heated to a temperature of 
50.degree. C. under nitrogen gas stream while stirring. 
##STR32## 
To the solution was added dropwise a mixed solution of each of the monomers 
shown in Table A below, 2.6 g of methyl 3-mercaptopropionate, 1.5 g of 
AIVN and 60 g of tetrahydrofuran over a period of one hour, followed by 
reacting for one hour. Then, 1.0 g of AIVN was added thereto and the 
temperature was adjusted to 70.degree. C., and the reaction was continued 
for 2 hours. To the reaction mixture was further added 0.8 g of AIVN, 
followed by reacting for 3 hours. To the reaction mixture was added 60 g 
of Isopar H, the tetrahydrofuran was distilled off under a reduced 
pressure of an aspirator at a temperature of 50.degree. C. After cooling, 
the reaction mixture was passed through a nylon cloth of 200 mesh to 
obtain a white dispersion which was a latex of good monodispersity. An 
average grain diameter of each of the resin grains was in a range of from 
0.15 to 0.30 .mu.m. An Mw thereof was in a range of from 9.times.10.sup.3 
to 1.5.times.10.sup.4 and a Tg thereof was in a range of from 35.degree. 
C. to 80.degree. C. 
TABLE A 
__________________________________________________________________________ 
Synthesis 
Example 
Resin 
Monomer Monomer 
of Resin 
Grain 
Corresponding to Corresponding to 
Grain (AR) 
(AR) Polymer Component (a) 
Polymer Component (b) 
Other Monomer 
__________________________________________________________________________ 
3 AR-3 2-Carboxyethyl acrylate 
-- Methyl methacrylate 
18 g 60 g 
Ethyl methacrylate 
22 g 
4 AR-4 Methacrylic acid 5 g 
##STR33## Phenethyl methacrylate 70 
g 
R': O(C.sub.2).sub.2 COC.sub.4 H.sub.9 
25 g 
5 AR-5 -- 
##STR34## Benzyl methacrylate 60 g 
40 g 
6 AR-6 -- 
##STR35## Ethyl methacrylate 30 g 
70 g 
7 AR-7 4-Vinylbenzene-sulfonic acid 7 g 
##STR36## Styrene 23 g Vinyltoluene 
30 g 
40 g 
8 AR-8 Itaconic anhydride 5 g 
##STR37## Methyl methacrylate 50 g 
Ethyl methacrylate 20 g 
25 g 
9 AR-9 Acrylic acid 8 g 
##STR38## 2-Methylphenyl methacrylate 
2 g 
20 g 
10 AR-10 
##STR39## 
##STR40## Methyl methacrylate 30 g 
5 g 30 g 
##STR41## 
35 g 
11 AR-11 
Acrylic acid -- Methyl methacrylate 
13 g 52 g 
2-(Butoxy carbonyl)ethyl 
methacrylate 
35 g 
__________________________________________________________________________ 
SYNTHESIS EXAMPLES 12 TO 17 OF RESIN GRAIN (AR): (AR-12) TO (AR-17) 
Each of the resin grains was synthesized in the same manner as in Synthesis 
Example 2 of Resin Grain (AR) except for using 10 g of each of the 
macromonomers (Mw thereof being in a range of from 8.times.10.sup.3 to 
1.times.10.sup.4) shown in Table B below in place of 10 g of Macromonomer 
(M-1). A polymerization ratio of each of the resin grains was in a range 
of from 98 to 99% and an average grain diameter thereof was in a range of 
from 0.15 to 0.25 .mu.m with good monodispersity. An Mw of each of the 
resin grains was in a range of from 9.times.10.sup.3 to 2.times.10.sup.4 
and a Tg thereof was in a range of from 40.degree. C. to 70.degree. C. 
TABLE B 
__________________________________________________________________________ 
Synthesis 
Example 
Resin 
of Resin 
Grain 
Grain (AR) 
(AR) 
Macromonomer 
__________________________________________________________________________ 
12 AR-12 
##STR42## 
13 AR-13 
##STR43## 
14 AR-14 
##STR44## 
15 AR-15 
##STR45## 
16 AR-16 
##STR46## 
17 AR-17 
##STR47## 
__________________________________________________________________________ 
SYNTHESIS EXAMPLE 18 OF RESIN GRAIN (AR): (AR-18) 
A mixed solution of 18 g of Dispersion Stabilizing Resin (Q-4) having the 
structure shown below and 560 g of Isopar H was heated to a temperature of 
55.degree. C. under nitrogen gas stream while stirring. 
##STR48## 
To the solution was dropwise added a mixed solution of 40 g of methyl 
methacrylate, 45 g of 2-propoxyethyl methacrylate, 15 g of acrylic acid, 
1.3 g of methyl 3-mercaptopropionate, 0.8 g of AIVN and 200 g of Isoper H 
over a period of one hour, followed by stirring for one hour. Then, 0.8 g 
of AIVN was added to the reaction mixture, the reaction was carried out 
for 2 hours and 0.5 g of AIBN was further added thereto and the reaction 
temperature was adjusted to 80.degree. C., followed by reacting for 3 
hours. After cooling, the reaction mixture was passed through a nylon 
cloth of 200 mesh to obtain a white dispersion which was a latex of good 
monodispersity having a polymerization ratio of 97% and an average grain 
diameter of 0.17 .mu.m. An Mw of the resin grain was 6.times.10.sup.3 and 
a Tg thereof was 25.degree. C. 
SYNTHESIS EXAMPLE 19 OF RESIN GRAIN (AR): (AR-19) 
A mixed solution of 15 g of Dispersion Stabilizing Resin (Q-1) described 
above, 62 g of vinyl acetate, 30 g of vinyl valerate, 8 g of crotonic acid 
and 275 g of Isopar H was heated to a temperature of 80.degree. C. under 
nitrogen gas stream with stirring. To the solution was added 1.6 g of 
AIVN, followed by reacting for 1.5 hours, 0.8 g of AIVN was added thereto, 
followed by reacting for 2 hours, and 0.5 g of AIBN was further added 
thereto, followed by reacting for 4 hours. Then, the temperature of the 
reaction mixture was raised to 100.degree. C. and stirred for 2 hours to 
distil off the unreacted monomers. After cooling, the reaction mixture was 
passed through a nylon cloth of 200 mesh to obtain a white dispersion 
which was a monodispersed latex with a polymerization ratio of 93% and an 
average grain diameter of 0.25 .mu.m. An Mw of the resin grain was 
8.times.10.sup.4 and a Tg thereof was 26.degree. C. 
SYNTHESIS EXAMPLE 20 OF RESIN GRAIN (AR): (AR-20) 
A mixed solution of 20 g of Dispersion Stabilizing Resin (Q-5) having the 
structure shown below, 60 g of methyl methacrylate, 30 g of ethyl 
acrylate, 10 g of acrylic acid, 3 g of thioglycolic acid and 546 g of 
Isopar H was heated to a temperature of 60.degree. C. under nitrogen gas 
stream while stirring. 
##STR49## 
To the solution was added 1.0 g of AIVN, followed by reacting for 2 hours, 
0.8 g of AIVN was added thereto, followed by reacting for 2 hours, and 0.5 
g of AIBN was further added thereto, the temperature was adjusted to 
80.degree. C., followed by reacting for 3 hours. After cooling, the 
reaction mixture was passed through a nylon cloth of 200 mesh to obtain a 
white dispersion which was a monodispersed latex with a polymerization 
ratio of 99% and an average grain diameter of 0.22 .mu.m. An Mw of the 
resin grain was 9.times.10.sup.3 and a Tg thereof was 23.degree. C. 
SYNTHESIS EXAMPLE 21 OF RESIN GRAIN (AR): (AR-21) 
A mixed solution of 18 g of Dispersion Stabilizing Resin (Q-6) having the 
structure shown below and 500 g of Isopar H was heated to a temperature of 
50.degree. C. under nitrogen gas stream with stirring. 
##STR50## 
To the solution was added dropwise a mixed solution of 35 g of methyl 
methacrylate, 40 g of 2,3-dipropoxycarbonylpropyl methacrylate, 25 g of 
2-sulfoethyl methacrylate, 5.2 g of methyl 3-mercaptopropionate, 1.5 g of 
AIVN and 120 g of tetrahydrofuran over a period of one hour, followed by 
further reacting for one hour. Then 1.0 g of AIVN was added to the 
reaction mixture, the temperature thereof was adjusted to 70.degree. C., 
and the reaction was conducted for 2 hours. Further, 1.0 g of AIVN was 
added thereto, followed by reacting for 3 hours. To the reaction mixture 
was added 120 g of Isopar H, the tetrahydrofuran was distilled off under a 
reduced pressure of an aspirator at a temperature of 50.degree. C. After 
cooling, the reaction mixture was passed through a nylon cloth of 200 mesh 
to obtain a white dispersion which was a latex of good monodispersity 
having a polymerization ratio of 98% and an average grain diameter of 0.18 
.mu.m. An Mw of the resin grain was 6.times.10.sup.3 and a Tg thereof was 
28.degree. C. 
SYNTHESIS EXAMPLE 22 OF RESIN GRAIN (AR): (AR-22) 
A mixed solution of 20 g of Dispersion Stabilizing Resin (Q-7) having the 
structure shown below, 15 g of a dimethylsiloxane monofunctional 
macromonomer (FM-0721 manufactured by Chisso Corp.; Mw: 6.times.10.sup.3), 
50 g of methyl methacrylate, 35 g of 2-pentyloxyethyl methacrylate, 15 g 
of acrylic acid, 6 g of methyl 3-mercaptopropionate, and 547 g of Isopar G 
was heated to a temperature of 60.degree. C. under nitrogen gas stream 
while stirring. 
##STR51## 
To the solution was added 2.0 g of AIVN, followed by reacting for 2 hours, 
1.0 g of AIVN was added to the reaction mixture, and the reaction was 
carried out for 2 hours. Then, 1.0 g of AIVN was further added thereto, 
the temperature was immediately adjusted to 75.degree. C., followed by 
reacting for 2 hours, and 0.8 g of AIVN was further added thereto, 
followed by reacting for 2 hours. After cooling, the reaction mixture was 
passed through a nylon cloth of 200 mesh to obtain a white dispersion 
which was a latex of good monodispersity having a polymerization ratio of 
98% and an average grain diameter of 0.20 .mu.m. An Mw of the resin grain 
was 6.5.times.10.sup.3 and a Tg thereof was 20.degree. C. 
SYNTHESIS EXAMPLES 23 TO 32 OF RESIN GRAIN (AR): (AR-23) TO (AR-32) 
A mixed solution of 25 g of Dispersion Stabilizing Resin (Q-8) having the 
structure shown below and 392 g of Isopar H was heated to a temperature of 
50.degree. C. under nitrogen gas stream while stirring. 
##STR52## 
To the solution was dropwise added a mixed solution of each of the monomers 
shown in Table C below, 3.1 g of methyl 3-mercaptopropionate, 3 g of ACPP 
and 150 g of methyl ethyl ketone over a period of one hour, followed by 
reacting for one hour. To the reaction mixture was further added 1.0 g of 
ACPP, followed by reacting for 2 hours. Then, 1.0 g of AIVN was added 
thereto and the temperature was immediately adjusted to 75.degree. C., and 
the reaction was continued for 2 hours. To the reaction mixture was 
further added 0.8 g of AIVN, followed by reacting for 2 hours. After 
cooling, the reaction mixture was passed through a nylon cloth of 200 mesh 
to obtain a white dispersion. A polymerization ratio of each of the white 
dispersions obtained was in a range of from 93 to 99% and an average grain 
diameter thereof was in a range of from 0.15 to 0.25 .mu.m with narrow 
size distribution. An Mw of each of the resin grains was in a range of 
from 8.times.10.sup.3 to 1.times.10.sup.4 and a Tg thereof was in a range 
of from 10.degree. C. to 35.degree. C. 
3 TABLE C 
- Synthesis 
Example Resin Monomer Monomer 
of Resin Grain Corresponding to Corresponding to 
Grain (AR) (AR) Polymer Component (a) Polymer Component (b) Other 
Monomer 
23 AR-23 Acryl 12.5 g -- Benzyl methacrylate 55 g 
2-Methoxyethyl 32.5 g 
24 AR-24 2-phosphonoethylmethacrylate 18 g 
##STR53## 
12.5 g Methyl methacrylateEthyl methacrylate 35.534 gg 
25 AR-25 
##STR54## 
8 g 
##STR55## 
30 g Methyl methacrylateMethyl acrylate 3527 gg 
26 AR-26 Acrylic acid 15 g -- Benzyl methacrylate 55 g 
##STR56## 
30 g 
27 AR-27 Acrylic acid 8 g -- 3-Phenylpropyl 64 g 
2-Sulfopropyl 8 g methacrylate 
methacrylate Diethylene glycol 20 g 
monomethyl ether 
monomethacrylate 
28 AR-28 Acrolein 10 g 
##STR57## 
15 g Methyl methacrylatePropyl acrylate 5025 gg 
29 AR-29 -- 
##STR58## 
28 g 
##STR59## 
72 g 
30 AR-30 -- 
##STR60## 
30 g Phenyl methacrylateMethyl acrylate 4030 gg 
31 AR-31 
##STR61## 
15 g 
##STR62## 
20 g Methyl methacrylate2,3-Dibutoxy-carbonylpropylmethacrylate 3530 gg 
32 AR-32 4-Vinylbenzene- 15 g -- Vinyl acetate 65 g 
carboxylic acid 4-Vinyltoluene 20 g 
SYNTHESIS EXAMPLE 1 OF RESIN GRAIN (ARW): (ARW-1) 
A mixed solution of the whole amount of dispersion of Resin Grain (AR-18) 
obtained by Synthesis Example 18 of Resin Grain (AR) (as seed) and 10 g of 
Dispersion Stabilizing Resin (Q-1) described above was heated to a 
temperature of 60.degree. C. under nitrogen gas stream with stirring. To 
the mixture was added dropwise a mixture of 85 g of benzyl methacrylate, 
15 g of acrylic acid, 2.0 g of methyl 3-mercaptopropionate, 0.8 g of AIVN 
and 200 g of Isopar H over a period of 2 hours, followed by further 
reacting for 2 hours. Then 0.8 g of AIVN was added to the reaction 
mixture, the temperature thereof was raised to 70.degree. C., and the 
reaction was conducted for 2 hours. Further, 0.6 g of AIVN was added 
thereto, followed by reacting for 3 hours. After cooling, the reaction 
mixture was passed through a nylon cloth of 200 mesh to obtain a white 
dispersion which was a latex of good monodispersity having a 
polymerization ratio of 98% and an average grain diameter of 0.24 .mu.m. 
In order to investigate that the resin grain thus-obtained was composed of 
the two kinds of resins, the state of resin grain was observed using a 
scanning electron microscope. 
Specifically, the dispersion of Resin Grain (ARW-1) was applied to a 
polyethylene terephthalate film so that the resin grains were present in a 
dispersive state on the film, followed by heating at a temperature of 
50.degree. C. or 80.degree. C. for 5 minutes to prepare a sample. Each 
sample was observed using a scanning electron microscope (JSL-T330 Type 
manufactured by JEOL Co., Ltd.) of 20,000 magnifications. As a result, the 
resin grains were observed with the sample heated at 50.degree. C. On the 
contrary, with the sample heated at 80.degree. C. the resin grains had 
been melted by heating and were not observed. 
The state of resin grain was observed in the same manner as described above 
with respect to resin grains formed from respective two kinds of resins 
(copolymers) constituting Resin Grain (ARW-1), i.e., Resin Grain (AR-18) 
and Resin Grain (AR-1) described above and a mixture of Resin Grains 
(AR-18) and (AR-1) in a weight ratio of 1:1. As a result, it was found 
that with Resin Grain (AR-18), the resin grains were not observed in the 
sample heated at 50.degree. C., although the resin grains were observed in 
the sample before heating. On the other hand, with Resin Grain (AR-1), the 
resin grains were not observed in the sample heated at 80.degree. C. 
Further, with the mixture of two kind of resin grains, disappearance of 
the resin grains was observed in the sample heated at 50.degree. C. in 
comparison with the sample before heating. 
From these results it was confirmed that Resin Grain (ARW-1) described 
above was not a mixture of two kinds of resin grains but contained two 
kinds of resins therein, and had a core/shell structure wherein the resin 
having a relatively high Tg formed shell portion and the resin having a 
relatively low Tg formed core portion. 
SYNTHESIS EXAMPLES 2 TO 14 OF RESIN GRAIN (ARW): (ARW-2) TO (ARW-14) 
Each of the resin grains (ARW-2) to (ARW-14) was synthesized in the same 
manner as in Synthesis Examples 1 of Resin Grain (ARW) except for using 
each of the monomers shown in Table D below in place of the monomers 
employed in Synthesis Example 1 of Resin Grain (ARW). A polymerization 
ratio of each of the resin grains was in a range of from 95 to 99% and an 
average grain diameter thereof was in a range of from 0.20 to 0.30 .mu.m 
with good monodispersity. 
TABLE D 
__________________________________________________________________________ 
Synthesis Resin 
Example of 
Grain Weight Weight 
Resin Grain (ARW) 
(ARW) Monomers for Seed Grain Ratio 
Monomers for Shell 
Ratioon 
__________________________________________________________________________ 
2 ARW-2 Methyl methacrylate 54 Methyl methacrylate 
47 
Ethyl acrylate 30 2-Propoxyethyl 
40thacrylate 
2-Sulfoethyl methacrylate 
16 Acrylic acid 13 
3 ARW-3 Methyl methacrylate 37 Vinyl acetate 80 
Methyl acrylate 45 Acrolein 20 
2-Carboxyethyl acrylate 18 
4 ARW-4 Benzyl methacrylate 86 Methyl methacrylate 
52 
Acrylic acid 14 2-(2-butoxyethoxy)ethyl 
30 
methacrylate 
3-Sulfopropyl 
18rylate 
5 ARW-5 Vinyl acetate 65 Methyl methacrylate 
40 
Vinyl butyrate 25 Methyl acrylate 
30 
2-Vinyl acetic acid 10 Monomer (b-1) 30 
6 ARW-6 Methyl methacrylate 52 3-Phenylpropyl 
84thacrylate 
2,3-Diacetyloxypropyl 35 Acrylic acid 16 
methacrylate 
Acrylic acid 13 
7 ARW-7 Methyl methacrylate 50 2-Phenoxyethyl 
80thacrylate 
2-Butoxycarbonylethyl 30 2-Carboxyethyl 
20thacrylate 
methacrylate 
2-Phosphonoethyl 20 
methacrylate 
8 ARW-8 Ethyl methacrylate 80 Methyl methacrylate 
64 
##STR63## 20 2-Methoxyethyl acrylate 
Acrylic acid 25 11 
9 ARW-9 Vinyl acetate 90 Benzyl methacrylate 
70 
Itaconic anhydride 10 Monomer (b-9) 25 
Acrylic acid 5 
10 ARW-10 
Methyl methacrylate 45 Benzyl methacrylate 
50 
Ethyl methacrylate 40 Monomer (b-8) 50 
Acrylic acid 15 
11 ARW-11 
Methyl methacrylate 50 Methyl methacrylate 
47 
Ethyl acrylate 20 2-Methoxycarbonylethyl 
40 
Monomer (b-1) 30 methacrylate 
Acrylic acid 13 
12 ARW-12 
Methyl methacrylate 52 Methyl methacrylate 
40 
Monomer (b-11) 40 Monomer (b-12) 60 
2-Hydroxyethyl 8 
methacrylate 
13 ARW-13 
Vinyl acetate 85 Ethyl methacrylate 
77 
##STR64## 15 Acrylic acid Macromonomer 
(M-3) 15 8 
14 ARW-14 
Phenethyl methacrylate 55 Benzyl methacrylate 
75 
methyl methacrylate 25 Macromonomer 
5-7) 
3-Sulfopropyl 20 Monomer (b-10) 20 
methacrylate 
__________________________________________________________________________ 
Synthesis Examples of Resin (P): 
SYNTHESIS EXAMPLE 1 OF RESIN (P): (P-1) 
A mixed solution of 80 g of methyl methacrylate, 20 g of a dimethylsiloxane 
macromonomer (FM-0725 manufactured by Chisso Corp.; Mw: 1.times.10.sup.4), 
and 200 g of toluene was heated to a temperature of 75.degree. C. under 
nitrogen gas stream. To the solution was added 1.0 g of AIBN, followed by 
reacting for 4 hours. To the mixture was further added 0.7 g of AIBN, and 
the reaction was continued for 4 hours. An Mw of the copolymer 
thus-obtained was 5.8.times.10.sup.4. 
##STR65## 
SYNTHESIS EXAMPLES 2 TO 9 OF RESIN (P): (P-2) TO (P-9) 
Each of copolymers was synthesized in the same manner as in Synthesis 
Example 1 of Resin (P), except for replacing methyl methacrylate and the 
macromonomer (FM-0725) with each monomer corresponding to the polymer 
component shown in Table E below. An Mw of each of the resulting polymers 
was in a range of from 4.5.times.10.sup.4 to 6.times.10.sup.4. 
3 TABLE E 
- 
##STR66## 
S 
ynthesis x/y/z 
Example of Resin (weight 
Resin (P) (P) R Y 
b W Z ratio) 
2 P-2 C.sub.2 
H.sub.5 
##STR67## 
CH.sub.3 COO(CH.sub.2).sub.2 
S 
##STR68## 
65/15/20 
3 P-3 CH.sub.3 
##STR69## 
H 
##STR70## 
##STR71## 
60/10/30 
4 P-4 CH.sub.3 
##STR72## 
CH.sub.3 
##STR73## 
##STR74## 
65/10/25 
5 P-5 C.sub.3 
H.sub.7 
##STR75## 
CH.sub.3 
##STR76## 
##STR77## 
65/15/20 
6 P-6 CH.sub.3 
##STR78## 
CH.sub.3 
##STR79## 
##STR80## 
50/20/30 
7 P-7 C.sub.2 
H.sub.5 
##STR81## 
H CONH(CH.sub.2).sub.2 
S 
##STR82## 
57/8/35 
8 P-8 CH.sub.3 
##STR83## 
H 
##STR84## 
##STR85## 
70/15/15 
9 P-9 C.sub.2 
H.sub.5 
##STR86## 
CH.sub.3 
##STR87## 
##STR88## 
70/10/20 
SYNTHESIS EXAMPLE 10 OF RESIN (P): (P-10) 
A mixed solution of 60 g of 2,2,3,4,4,4-hexafluorobutyl methacrylate, 40 g 
of a methyl methacrylate macromonomer (AA-6 manufactured by Toagosei 
Chemical Industry Co., Ltd.; Mw: 1.times.10.sup.4), and 200 g of 
benzotrifluoride was heated to a temperature of 75.degree. C. under 
nitrogen gas stream. To the solution was added 1.0 g of AIBN, followed by 
reacting for 4 hours. To the mixture was further added 0.5 g of AIBN, and 
the reaction was continued for 4 hours. An Mw of the copolymer 
thus-obtained was 6.5.times.10.sup.4. 
##STR89## 
SYNTHESIS EXAMPLES 11 TO 15 OF RESIN (P): (P-11) TO (P-15) 
Each of copolymers was synthesized in the same manner as in Synthesis 
Example 10 of Resin (P), except for replacing the monomer and the 
macromonomer used in Synthesis Example 10 of Resin (P) with each monomer 
and each macromonomer both corresponding to the polymer components shown 
in Table F below. An Mw of each of the resulting copolymers was in a range 
of from 4.5.times.10.sup.4 to 6.5.times.10.sup.4. 
TABLE F 
__________________________________________________________________________ 
##STR90## 
__________________________________________________________________________ 
Synthesis 
Example of 
Resin 
Resin (P) 
(P) 
a R Y 
__________________________________________________________________________ 
11 P-11 
CH.sub.3 
(CH.sub.2).sub.2 C.sub.n F.sub.2n+1 n = 8.about.10 
-- CH.sub.3 
12 P-12 
CH.sub.3 
(CH.sub.2).sub.2 CF.sub.2 CFHCF.sub.3 
-- H 
13 P-13 
CH.sub.3 
CH.sub.2 CF.sub.2 CF.sub.2 H 
##STR91## CH.sub.3 
14 P-14 
H CH.sub.2 CF.sub.2 CFHCF.sub.3 
##STR92## CH.sub.3 
15 P-15 
CH.sub.3 
##STR93## -- CH.sub.3 
__________________________________________________________________________ 
Synthesis 
Example of x/y/z p/g 
Resin (P) 
R' Z' (weight ratio) 
(weight ratio) 
__________________________________________________________________________ 
11 CH.sub.3 
##STR94## 70/0/30 
70/30 
12 CH.sub.3 
##STR95## 60/0/40 
70/30 
13 -- 
##STR96## 40/30/30 
90/10 
14 C.sub.2 H.sub.5 
##STR97## 30/45/25 
60/40 
15 C.sub.2 H.sub.5 
##STR98## 80/0/20 
90/10 
__________________________________________________________________________ 
SYNTHESIS EXAMPLE 16 OF RESIN (P): (P-16) 
A mixed solution of 67 g of methyl methacrylate, 22 g of methyl acrylate, 1 
g of methacrylic acid, and 200 g of toluene was heated to a temperature of 
80.degree. C. under nitrogen gas stream. To the solution was added 10 g of 
Polymer Azobis Initiator (PI-1) having the structure shown below, followed 
by reacting for 8 hours. After completion of the reaction, the reaction 
mixture was poured into 1.5 l of methanol, and the precipitate 
thus-deposited was collected and dried to obtain 75 g of a copolymer 
having an Mw of 3.times.10.sup.4. 
##STR99## 
SYNTHESIS EXAMPLE 17 OF RESIN (P): (P-17) 
A mixed solution of 70 g of methyl methacrylate and 200 g of 
tetrahydrofuran was thoroughly degassed under nitrogen gas stream and 
cooled to -20.degree. C. To the solution was added 0.8 g of 
1,1-diphenylbutyl lithium, followed by reacting for 12 hours. To the 
reaction mixture was then added a mixed solution of 30 g of Monomer (m-1) 
shown below and 60 g of tetrahydrofuran which had been thoroughly degassed 
under nitrogen gas stream, followed by reacting for 8 hours. 
After rendering the mixture to 0.degree. C., 10 ml of methanol was added 
thereto to conduct a reaction for 30 minutes to stop the polymerization. 
The resulting polymer solution was heated to a temperature of 30.degree. 
C. with stirring, and 3 ml of a 30% ethanol solution of hydrogen chloride 
was added thereto, followed by stirring for 1 hour. The reaction mixture 
was distilled under reduced pressure to remove the solvent until the 
volume was reduced to half and the residue was reprecipitated in 1 l of 
petroleum ether. The precipitate was collected and dried under reduced 
pressure to obtain 76 g of a polymer having an Mw of 6.8.times.10.sup.4. 
##STR100## 
SYNTHESIS EXAMPLE 18 OF RESIN (P): (P-18) 
A mixed solution of 52.5 g of methyl methacrylate, 22.5 g of methyl 
acrylate, 0.5 g of methylaluminum tetraphenylporphynate, and 200 g of 
methylene chloride was heated to a temperature of 30.degree. C. under 
nitrogen gas stream. The solution was irradiated with light from a xenon 
lamp of 300 W at a distance of 25 cm through a glass filter for 20 hours. 
To the mixture was added 25 g of Monomer (m-2) shown below, and the 
resulting mixture was further irradiated with light under the same 
conditions as above for 12 hours. To the reaction mixture was added 3 g of 
methanol, followed by stirring for 30 minutes to stop the reaction. The 
reaction mixture was reprecipitated in 1.5 l of methanol, and the 
precipitate was collected and dried to obtain 78 g of a polymer having an 
Mw of 7.times.10.sup.4. 
##STR101## 
SYNTHESIS EXAMPLE 19 OF RESIN (P): (P-19) 
A mixture of 50 g of ethyl methacrylate, 10 g of glycidyl methacrylate, and 
4.8 g of benzyl N,N-diethyldithiocarbamate was sealed into a container 
under nitrogen gas stream and heated to a temperature of 50.degree. C. The 
mixture was irradiated with light from a high-pressure mercury lamp of 400 
W at a distance of 10 cm through a glass filter for 6 hours to conduct 
photopolymerization. The reaction mixture was dissolved in 100 g of 
tetrahydrofuran, and 40 g of Monomer (m-3) shown below was added thereto. 
After displacing the atmosphere with nitrogen, the mixture was again 
irradiated with light for 10 hours. The reaction mixture obtained was 
reprecipitated in 1 l of methanol, and the precipitate was collected and 
dried to obtain 73 g of a polymer having an Mw of 4.8.times.10.sup.4. 
##STR102## 
SYNTHESIS EXAMPLE 20 OF RESIN (P): (P-20), 
A mixture of 50 g of methyl methacrylate, 25 g of ethyl methacrylate, and 
1.0 g of benzyl isopropylxanthate was sealed into a container under 
nitrogen gas stream and heated to a temperature of 50.degree. C. The 
mixture was irradiated with light from a high-pressure mercury lamp of 400 
W at a distance of 10 cm through a glass filter for 6 hours to conduct 
photopolymerization. To the mixture was added 25 g of Monomer (m-1) 
described above. After displacing the atmosphere with nitrogen, the 
mixture was again irradiated with light for 10 hours. The reaction mixture 
obtained was reprecipitated in 2 l of methanol, and the precipitate was 
collected and dried to obtain 63 g of a polymer having an Mw of 
6.times.10.sup.4. 
##STR103## 
SYNTHESIS EXAMPLES 21 TO 27 OF RESIN (P): (P-21) TO (P-27) 
Each of copolymers shown in Table G below was prepared in the same manner 
as in Synthesis Example 19 of Resin (P). An Mw of each of the resulting 
polymers was in a range of from 3.5.times.10.sup.4 to 6.times.10.sup.4. 
TABLE G 
__________________________________________________________________________ 
Synthesis 
Example of 
Resin 
Resin (P) 
(P) AB Type Block Copolymer (weight ratio) 
__________________________________________________________________________ 
21 P-21 
##STR104## 
22 P-22 
##STR105## 
23 P-23 
##STR106## 
24 P-24 
##STR107## 
25 P-25 
##STR108## 
26 P-26 
##STR109## 
27 P-27 
##STR110## 
__________________________________________________________________________ 
SYNTHESIS EXAMPLE 28 OF RESIN (P): (P-28) 
A copolymer having an Mw of 4.5.times.10.sup.4 was prepared in the same 
manner as in Synthesis Example 19 of Resin (P), except for replacing 
benzyl N,N-diethyldithiocarbamate with 18 g of Initiator (I-1) having the 
structure shown below. 
##STR111## 
SYNTHESIS EXAMPLE 29 OF RESIN (P): (P-29) 
A copolymer having an Mw of 2.5.times.10.sup.4 was prepared in the same 
manner as in Synthesis Example 20 of Resin (P), except for replacing 
benzyl isopropylxanthate with 0.8 g of Initiator (I-2) having the 
structure shown below. 
##STR112## 
SYNTHESIS EXAMPLE 30 OF RESIN (P): (P-30) 
A mixed solution of 68 g of methyl methacrylate, 22 g of methyl acrylate, 
10 g of glycidyl methacrylate, 17.5 g of Initiator (I-3) having the 
structure shown below, and 150 g of tetrahydrofuran was heated to a 
temperature of 50.degree. C. under nitrogen gas stream. The solution was 
irradiated with light from a high-pressure mercury lamp of 400 W at a 
distance of 10 cm through a glass filter for 10 hours to conduct 
photopolymerization. The reaction mixture obtained was reprecipitated in 1 
l of methanol, and the precipitate was collected and dried to obtain 72 g 
of a polymer having an Mw of 4.0.times.10.sup.4. 
A mixed solution of 70 g of the resulting polymer, 30 g of Monomer (m-2) 
described above, and 100 g of tetrahydrofuran was heated to a temperature 
of 50.degree. C. under nitrogen gas stream and irradiated with light under 
the same conditions as above for 13 hours. The reaction mixture was 
reprecipitated in 1.5 l of methanol, and the precipitate was collected and 
dried to obtain 78 g of a copolymer having an Mw of 6.times.10.sup.4. 
##STR113## 
SYNTHESIS EXAMPLES 31 TO 38 OF RESIN (P): (P-31) TO (P-38) 
In the same manner as in Synthesis Example 30 of Resin (P), except for 
replacing 17.5 g of Initiator (I-3) with 0.031 mol of each of the 
initiators shown in Table H below, each of the copolymers shown in Table H 
was obtained. A yield thereof was in a range of from 70 to 80 g and an Mw 
thereof was in a range of from 4.times.10.sup.4 to 6.times.10.sup.4. 
3 TABLE H 
- 
##STR114## 
##STR115## 
##STR116## 
##STR117## 
##STR118## 
##STR119## 
31 P-31 
##STR120## 
##STR121## 
##STR122## 
32 P-32 
##STR123## 
##STR124## 
##STR125## 
33 P-33 
##STR126## 
##STR127## 
##STR128## 
34 P-34 
##STR129## 
##STR130## 
##STR131## 
35 P-35 
##STR132## 
##STR133## 
##STR134## 
36 P-36 
##STR135## 
##STR136## 
##STR137## 
37 P-37 
##STR138## 
##STR139## 
##STR140## 
38 P-38 
##STR141## 
##STR142## 
##STR143## 
Synthesis Examples of Resin Grain (PL): 
SYNTHESIS EXAMPLE 1 OF RESIN GRAIN (PL): (PL-1) 
A mixed solution of 40 g of Monomer (LM-1) having the structure shown 
below, 2 g of ethylene glycol dimethacrylate, 4.0 g of Dispersion 
Stabilizing Resin (LP-1) having the structure shown below, and 180 g of 
methyl ethyl ketone was heated to a temperature of 60.degree. C. with 
stirring under nitrogen gas stream. To the solution was added 0.3 g of 
AIVN, followed by reacting for 3 hours. To the reaction mixture was 
further added 0.1 g of AIVN, and the reaction was continued for 4 hours. 
After cooling, the reaction mixture was passed through a nylon cloth of 
200 mesh to obtain a white dispersion. The average grain diameter of the 
latex was 0.25 .mu.m. 
##STR144## 
SYNTHESIS EXAMPLE 2 OF RESIN GRAIN (PL): (PL-2) 
A mixed solution of 5 g of AB-6 (monofunctional macromonomer comprising 
butyl acrylate unit, manufactured by Toagosei Chemical Industry Co., Ltd.) 
as a dispersion stabilizing resin and 140 g of methyl ethyl ketone was 
heated to a temperature of 60.degree. C. under nitrogen gas stream while 
stirring. To the solution was added dropwise a mixed solution of 40 g of 
Monomer (LM-2) having the structure shown below, 1.5 g of ethylene glycol 
diacrylate, 0.2 g of AIVN, and 40 g of methyl ethyl ketone over a period 
of one hour. After the addition, the reaction was continued for 2 hours. 
To the reaction mixture was further added 0.1 g of AIVN, followed by 
reacting for 3 hours to obtain a white dispersion. After cooling, the 
dispersion was passed through a nylon cloth of 200 mesh. The average grain 
diameter of the dispersed resin grains was 0.35 .mu.m. 
##STR145## 
SYNTHESIS EXAMPLES 3 TO 11 OF RESIN GRAIN (PL): (PL-3) TO (PL-11) 
Each of resin grains was synthesized in the same manner as in Synthesis 
Example 1 of Resin Grain (PL), except for replacing Monomer (LM-1), 
ethylene glycol dimethacrylate and methyl ethyl ketone with each of the 
compounds shown in Table I below, respectively. An average grain diameter 
of each of the resulting resin grains was in a range of from 0.15 to 0.30 
.mu.m. 
TABLE I 
__________________________________________________________________________ 
Synthesis 
Resin 
Example of 
Grain Crosslinking Poly- 
Reaction 
Resin Grain (PL) 
(PL) 
Monomer (LM) functional Monomer 
Amount 
Solvent 
__________________________________________________________________________ 
3 PL-3 
##STR146## Ethylene glycol dimethacrylate 
2.5 g 
Methyl ethyl ketone 
4 PL-4 
##STR147## Divinylbenzene 
3 g 
Methyl ethyl ketone 
5 PL-5 
##STR148## -- Methyl ethyl ketone 
6 PL-6 
##STR149## Diethylene glycol diacrylate 
5 g 
n-Hexane 
7 PL-7 
##STR150## Ethylene glycol dimethacrylate 
3.5 g 
n-Hexane 
8 PL-8 
##STR151## Trimethylolpropane trimethacrylate 
2.5 g 
Methyl ethyl ketone 
9 PL-9 
##STR152## Trivinylbenzene 
3.3 g 
Ethyl acetate/ 
n-Hexane (4/1 by 
weight) 
10 PL-10 
##STR153## Divinyl glutaconate 
4 g 
Ethyl acetate/ 
n-Hexane (2/1 by 
weight) 
11 PL-11 
##STR154## Propylene glycol diacrylate 
3 g 
Methyl ethyl 
__________________________________________________________________________ 
ketone 
SYNTHESIS EXAMPLES 12 TO 15 OF RESIN GRAIN (PL): (PL-12) TO (PL-15) 
Each of resin grains was synthesized in the same manner as in Synthesis 
Example 2 of Resin Grain (PL), except for replacing 40 g of Monomer (LM-2) 
with each of the monomers shown in Table J below and replacing 5 g of AB-6 
(dispersion stabilizing resin) with 6 g of Dispersion Stabilizing Resin 
(LP-8) having the structure shown below. An average grain diameter of each 
of the resulting resin grains was in a range of from 0.05 to 0.20 .mu.m. 
##STR155## 
TABLE J 
__________________________________________________________________________ 
Synthesis 
Resin 
Example of 
Grain 
Resin Grain (PL) 
(PL) 
Monomer (LM) Amount 
Other Monomer Amount 
__________________________________________________________________________ 
12 PL-12 
30 g 
##STR156## 10 g 
13 PL-13 
##STR157## 25 g Glycidyl methacrylate 
15 g 
14 PL-14 
##STR158## 25 g 
##STR159## 15 g 
15 PL-15 
##STR160## 20 g Vinyl acetate 20 
__________________________________________________________________________ 
g 
EXAMPLE 1 
A mixture of 2 g of X-form metal-free phthalocyanine (manufactured by 
Dainippon Ink and Chemicals, Inc.), 8 g of Binder Resin (B-1) having the 
structure shown below, 2 g of Resin (P-1), 0.15 g of Compound (A) having 
the structure shown below, and 80 g of tetrahydrofuran was put into a 500 
ml-volume glass container together with glass beads and dispersed in a 
paint shaker (manufactured by Toyo Seiki Seisakusho Co.) for 60 minutes. 
To the dispersion were added 0.1 g of phthalic anhydride and 0.02 g of 
o-chlorophenol, followed by further dispersing for 5 minutes. The glass 
beads were separated by filtration to prepare a dispersion for a 
light-sensitive layer. 
##STR161## 
The resulting dispersion was coated on base paper for a paper master having 
a thickness of 0.2 mm, which had been subjected to electrically conductive 
treatment and solvent-resistant treatment, by a wire bar, set to touch, 
and heated in a circulating oven at 110.degree. C. for 20 seconds to form 
a light-sensitive layer having a thickness of 8 .mu.m. The adhesion 
strength of the surface of the resulting electrophotographic 
light-sensitive element measured according to JIS Z 0237-1980 "Testing 
methods of pressure sensitive adhesive tapes and sheets" was 2 gram.force 
(g.f). 
For comparison, an electrophotographic light-sensitive element was prepared 
in the same manner as described above except for eliminating 2 g of Resin 
(P-1) according to the present invention. The adhesive strength of the 
surface thereof was more than 450 g.f and did not exhibit releasability at 
all. 
The light-sensitive element having the surface of releasability was 
installed in an apparatus as shown in FIG. 2 as a light-sensitive element 
11. On the other hand, a drum wound with a blanket for offset printing 
(9600-A manufactured by Meiji Rubber & Co., Ltd.) having the adhesive 
strength of 80 g.f/10 mm width and a thickness of 1.6 mm was installed as 
primary receptor 20. A device for providing transfer layer 13 was omitted 
and instead, an electrodeposition unit 14T was installed in a liquid 
developing unit set 14 as shown in FIG. 3. 
A toner image was first formed on the light-sensitive element by an 
electrophotographic process. Specifically, the light-sensitive element 11 
was charged to +450 V with a corona charger 18 in dark and image-exposed 
to light using a semiconductor laser having an oscillation wavelength of 
788 nm as an exposure device 19 at an irradiation dose on the surface of 
the light-sensitive element of 30 erg/cm.sup.2 based on digital image data 
of an information which had been obtained by reading an original by a 
color scanner, conducting several corrections relating to color 
reproduction peculiar to color separation system and stored in a hard 
disc. 
Thereafter, the exposed light-sensitive element was subjected to reversal 
development using Liquid Developer (LD-1) prepared in the manner as 
described below in a developing machine while applying a bias voltage of 
+400 V to a development electrode to thereby electrodeposit toner 
particles on the exposed areas. The light-sensitive element was then 
rinsed in a bath of Isopar H alone to remove stains on the non-image 
areas. 
Preparation of Liquid Developer (LD-1) 
1) Synthesis of Toner Particles: 
A mixed solution of 65 g of methyl methacrylate, 35 g of methyl acrylate, 
20 g of a dispersion polymer having the structure shown below, and 680 g 
of Isopar H was heated to 65.degree. C. under nitrogen gas stream with 
stirring. To the solution was added 1.2 g of 2,2'-azobis(isovaleronitrile) 
(AIVN), followed by reacting for 2 hours. To the reaction mixture was 
further added 0.5 g of AIVN, and the reaction was continued for 2 hours. 
To the reaction mixture was further added 0.5 g of AIVN, and the reaction 
was continued for 2 hours. The temperature was raised up to 90.degree. C., 
and the mixture was stirred under a reduced pressure of 30 mm Hg for 1 
hour to remove any unreacted monomers. After cooling to room temperature, 
the reaction mixture was filtered through a nylon cloth of 200 mesh to 
obtain a white dispersion. The reaction rate of the monomers was 95%, and 
the resulting dispersion had an average grain diameter of resin grain of 
0.25 .mu.m (grain diameter being measured by CAPA-500 manufactured by 
Horiba, Ltd.) and good monodispersity. 
##STR162## 
2) Preparation of Colored Particles: 
Ten grams of a tetradecyl methacrylate/methacrylic acid copolymer (95/5 
ratio by weight), 10 g of nigrosine, and 30 g of Isopar G were put in a 
paint shaker (manufactured by Toyo Seiki Seisakusho Co.) together with 
glass beads and dispersed for 4 hours to prepare a fine dispersion of 
nigrosine. 
3) Preparation of Liquid Developer: 
A mixture of 45 g of the above-prepared toner particle dispersion, 25 g of 
the above-prepared nigrosine dispersion, 0.2 g of a hexadecene/maleic acid 
monooctadecylamide copolymer (1/1 ratio by mole), and 15 g of branched 
octadecyl alcohol (FOC-1800 manufactured by Nissan Chemical Industries, 
Ltd.) was diluted with 1 l of Isopar G to prepare Liquid Developer (LD-1) 
for electrophotography. 
The light-sensitive element was then subjected to fixing by means of a heat 
roll whereby the toner image thus-formed was fixed. 
On the light-sensitive element bearing the toner image was provided a 
transfer layer by the electrodeposition coating method using the 
electrodeposition unit 14T. 
Specifically, on the surface of light-sensitive element 11 bearing the 
toner image which was rotated at a circumferential speed of 10 mm/sec, 
Dispersion of Resin (A) (L-1) shown below was supplied using a slit 
electrodeposition device, while putting the light-sensitive element to 
earth and applying an electric voltage of 250 V to an electrode of the 
slit electrodeposition device, whereby the resin grains were 
electrodeposited. The dispersion medium was removed by air-squeezing using 
a suction/exhaust unit, and the resin grains were fused by an infrared 
line heater as a pre-heating means at temperature of 80.degree. C. to form 
a film, whereby the transfer layer composed of a thermoplastic resin was 
prepared on the light-sensitive element. A thickness of the transfer layer 
was 5 .mu.m. 
______________________________________ 
Dispersion of Resin (A) (L-1) 
______________________________________ 
Resin Grain (AR-4) 5 g 
(solid basis) 
Resin Grain (AR-18) 5 g 
(solid basis) 
Charge Control Agent (D-1) 
0.03 g 
(octadecyl vinyl ether/N-tert-octyl 
maleic monoamide copolymer 
(1:1 by molar ratio)) 
Silicone oil 5 g 
(KF-69 manufactured by Shin-Etsu 
Silicone K.K.) 
Isopar H up to make 1 
liter 
______________________________________ 
The drum of light-sensitive element 11, the surface temperature of which 
had been adjusted at 80.degree. C., and the drum of primary receptor 20 
whose surface temperature had been adjusted at 120.degree. C. by 
temperature controller 17 were brought into contact with each other under 
the condition of a nip pressure of 5 kgf/cm.sup.2 and a drum 
circumferential speed of 5 mm/sec, whereby the toner image was wholly 
transferred together with the transfer layer onto the primary receptor. 
Then, an aluminium substrate used for the production of FUJI PS-Plate FPD 
(manufactured by Fuji Photo Film Co., Ltd.) was introduced as a receiving 
material 30 on back-up roller for transfer 31 adjusted at 130.degree. C. 
and back-up roller for release 32 adjusted at 10.degree. C. and the 
aluminum substrate was brought into contact with the primary receptor of 
drum type, the surface temperature of which had been adjusted at 
90.degree. C. by the temperature controller 17, under a nip pressure of 10 
kgf/cm.sup.2 and at a drum circumferential speed of 10 mm/sec. The toner 
images were wholly transferred onto the aluminum substrate and thus clear 
images of good image quality were obtained. 
For comparison, the same procedure as above was performed except that the 
transfer layer was not formed on the light-sensitive element to form a 
toner image on an aluminum substrate. In the resulting image on aluminum 
substrate, cuttings of toner image and unevenness in image density were 
observed. Further, as a result of visual evaluation of the toner image 
using a magnifying glass of 20 magnifications, cuttings of fine image, for 
example, fine lines and fine letters were recognized. Also, the residue of 
toner image was found on the surface of light-sensitive element. 
From these results, it can be seen that the method according to the present 
invention comprising providing a transfer layer on a light-sensitive 
element bearing a toner image and transferring the toner image together 
with the transfer layer onto a primary receptor and then onto a final 
receiving material is extremely good as a method for transferring toner 
image from a light-sensitive element to a receiving material. 
Further, a method of transferring a toner image directly onto an aluminum 
substrate without the intermediation of primary receptor was conducted. 
Specifically, an aluminum substrate was set between the drum of 
light-sensitive element 11 and the drum of primary receptor 20 and the 
toner image was transferred together with the transfer layer from the 
light-sensitive element onto the aluminum substrate under the same 
transfer condition as described above. As a result of visual evaluation of 
the toner image on the aluminum substrate, cuttings of fine image was 
observed. Also, the residue of toner image and transfer layer was 
recognized on the surface of light-sensitive element. 
Then, the plate of aluminum substrate having thereon the transfer layer was 
subjected to an oil-desensitizing treatment (i.e., removal of the transfer 
layer) to prepare a printing plate and its printing performance was 
evaluated. Specifically, the plate was immersed in Oil-Desensitizing 
Solution (E-1) having the composition shown below at 35.degree. C. for one 
minute with mild rubbing with a fur brush to remove the transfer layer, 
thoroughly washed with water, and gummed to prepare an offset printing 
plate. 
Oil-Desensitizing Solution (E-1) 
A solution prepared by diluting PS plate processing solution (DP-4 
manufactured by Fuji Photo Film Co., Ltd.) 50-fold with distilled water 
(pH: 12.5) 
The printing plate thus obtained was observed visually using an optical 
microscope of 200 magnifications. It was found that the non-image areas 
had no residual transfer layer, and the image areas suffered no defects in 
high definition regions (i.e., cutting of fine lines and fine letters). 
The printing plate was subjected to printing on neutral paper with various 
offset printing color inks using an offset printing machine (Oliver 94 
Model manufactured by Sakurai Seisakusho K. K.), and an aqueous solution 
(pH: 7.0) prepared by diluting dampening water for PS plate (SG-23 
manufactured by Tokyo Ink K. K.) 130-fold with distilled water, as 
dampening water. As a result, more than 60,000 prints with clear images 
free from background stains were obtained irrespective of the kind of 
color ink. 
Moreover, when the printing plate according to the present invention was 
exchanged for an ordinary PS plate and printing was continued under 
ordinary conditions, no trouble arose. It was thus confirmed that the 
printing plate according to the present invention can share a printing 
machine with other offset printing plates such as PS plates. 
As described above, the offset printing plate according to the present 
invention exhibits excellent performance in that an image formed by a 
scanning exposure system using semiconductor laser beam has excellent 
image reproducibility and the image of the plate can be reproduced on 
prints with satisfactory quality, in that the plate exhibits sufficient 
color ink receptivity without substantial ink-dependency to enable to 
perform full color printing with high printing durability, and in that it 
can share a printing machine in printing with other offset printing plates 
without any trouble. 
EXAMPLE 2 
An amorphous silicon electrophotographic light-sensitive element 
(manufactured by Kyocera Corp.) was immersed in a solution containing 1 g 
of Compound (S-1) for imparting releasability shown below dissolved in one 
liter of Isopar G for 10 seconds, rinsed with Isopar G and dried. By this 
treatment, the surface of amorphous silicon light-sensitive element was 
modified so as to exhibit the desired releasability and its adhesive 
strength was decreased from 200 gf to 3 gf. 
Compound (S-1) 
Silicone surface active agent (SILWet FZ-2171 manufactured by Nippon Unicar 
Co., Ltd.) 
##STR163## 
The resulting electrophotographic light-sensitive element was installed in 
an apparatus as shown in FIG. 2. The amorphous silicon electrophotographic 
light-sensitive element having the releasability was charged to +700 V 
with a corona discharge in a dark place and exposed to light using a 
semiconductor laser having an oscillation wavelength of 780 nm on the 
basis of digital image data of an information which had been obtained by 
reading an original by a color scanner, conducting several corrections 
relating to color reproduction peculiar to color separation system and 
stored in a hard disc. The potential in the exposed area was +220 V while 
it was +600 V in the unexposed area. 
The exposed light-sensitive element was pre-bathed with Isopar H 
(manufactured by Esso Standard Oil Co.) by a pre-bathing means installed 
in a developing unit and then subjected to reversal development by 
supplying Liquid Developer (LD-1) described above from the developing unit 
to the surface of light-sensitive element while applying a bias voltage of 
+500 V to the developing unit side to thereby electrodeposite toner 
particles on the exposed areas. The light-sensitive element was then 
rinsed in a bath of Isopar H alone to remove stains in the non-image areas 
and dried by a suction/exhaust unit. 
The light-sensitive element having the toner images was passed under an 
infrared line heater to maintain a surface temperature thereof measured by 
a radiation thermometer at about 80.degree. C. Resin (A-1) shown below was 
coated as a resin for transfer layer on the surface of light-sensitive 
element bearing the toner image at a rate of 20 mm/sec by a hot-melt 
coater adjusted at 80.degree. C. as a device for providing transfer layer 
13 and cooled by blowing cool air from a suction/exhaust unit to form a 
transfer layer. A thickness of the transfer layer was 2.5 .mu.m. 
##STR164## 
On the other hand, a primary receptor was prepared by applying a mixture of 
100 g of isoprene rubber, 7 g of Resin (P-2) and 0.001 g of phthalic 
anhydride to the surface of blanket for offset printing (9600-A) described 
in Example 1 and heated at 140.degree. C. for 2 hours to form a cured 
layer having a thickness of 10 .mu.m. The adhesive strength of the surface 
of the resulting primary receptor was 80 g.f. 
After heating the primary receptor 20 at its surface temperature of 
100.degree. C., the light-sensitive element 11 bearing the toner image and 
the transfer layer thereon was brought into contact with the primary 
receptor drum under the condition of a nip pressure of 4 kgf/cm.sup.2 and 
a drum circumferential speed of 5 mm/sec, whereby the toner images were 
wholly transferred together with the transfer layer onto the primary 
receptor 20. 
Then, an aluminum substrate for FPD plate was introduced as a receiving 
material 30 on back-up roller for transfer 31 adjusted at 130.degree. C. 
and back-up roller for release 32 adjusted at 10.degree. C. and the 
aluminum substrate was brought into contact with the primary receptor of 
drum type, the surface temperature of which had been adjusted at 
60.degree. C. by temperature controller 17, under a nip pressure of 5 
kgf/cm.sup.2 and at a drum circumferential speed of 10 mm/sec. The toner 
image was wholly transferred onto the aluminum substrate and thus clear 
images of good image quality were obtained. 
For comparison, the same procedure as above was performed except that the 
transfer layer was not formed on the toner image. In the resulting image 
on aluminum substrate, cuttings of toner image and unevenness in image 
density were observed. Further, as a result of visual evaluation of the 
image using a magnifying glass of 20 magnifications, cuttings of fine 
image, for example, fine lines and fine letters were recognized. Also, the 
residue of toner image was found on the surface of light-sensitive 
element. 
These results indicate that cleaning of the surface of light-sensitive 
element is necessary for removing the residual toner when the 
light-sensitive element is repeatedly employed. Consequently, a device for 
the cleaning must be provided and a problem in that the surface of 
light-sensitive element is damaged due to the cleaning arises. 
On the contrary, the method according to the present invention has 
advantages in that the release of toner image from the light-sensitive 
element is sufficiently performed and in that the toner image is easily 
and sufficiently transferred from the primary receptor to the receiving 
material and thus, it does not cause the problems as described above. 
Moreover, the excellent printing performance similar to that of Example 1 
was obtained as a result of the evaluation of the resulting printing plate 
in the same manner as in Example 1. 
EXAMPLE 3 
The formation of transfer layer on light-sensitive element bearing toner 
image was performed by the transfer method from release paper using a 
device as shown in FIG. 4 instead of the electrodeposition coating method 
as described in Example 1. Specifically, on Separate Shi (manufactured by 
Oji Paper Co., Ltd.) as release paper 24, was coated a mixture of Resin 
(A-2) described below and Resin (A-3) described below in a weight ratio of 
1:1 to prepare a transfer layer having a thickness of 4 .mu.m. The 
resulting paper was brought into contact with the light-sensitive element 
bearing the toner image same as described in Example 1 under the condition 
of a pressure between rollers of 3 kgf/cm.sup.2, a surface temperature of 
60.degree. C. and a transportation speed of 10 mm/sec, whereby the 
transfer layer 12 having a thickness of 4 .mu.m was formed on the 
light-sensitive element 11. 
##STR165## 
Using the light-sensitive element having the transfer layer thus prepared, 
a printing plate was formed, followed by conducting printing in the same 
manner as in Example 1. The image quality of prints obtained and printing 
durability were good as those in Example 1. 
EXAMPLE 4 
A mixture of 2 g of X-form metal-free phthalocyanine (manufactured by 
Dainippon Ink and Chemicals, Inc.), 8 g of Binder Resin (B-2) having the 
structure shown below, 2 g of Binder Resin (B-3) having the structure 
shown below, 0.15 g of Compound (B) having the structure shown below, and 
80 g of tetrahydrofuran was put into a 500 ml-volume glass container 
together with glass beads and dispersed in a paint shaker (manufactured by 
Toyo Seiki Seisakusho Co.) for 60 minutes. The glass beads were separated 
by filtration to prepare a dispersion for a light-sensitive layer. 
##STR166## 
The resulting dispersion was coated on base paper for a paper master having 
a thickness of 0.2 mm, which had been subjected to electrically conductive 
treatment and solvent-resistant treatment, by a wire bar, set to touch, 
and heated in a circulating oven at 110.degree. C. for 20 seconds to form 
a light-sensitive layer having a thickness of 8 .mu.m. 
On the light-sensitive layer was formed a surface layer for imparting 
releasability. Specifically, a coating composition comprising 10 g of 
silicone resin having the structure shown below, 1 g of cross-linking 
agent having the structure shown below, 0.1 g of platinum as a catalyst 
for crosslinking and 100 g of n-hexane was coated by a wire round rod, set 
to touch, and heated at 120.degree. C. for 10 minutes to form the surface 
layer having a thickness of 1.5 .mu.m. The adhesive strength of the 
surface of the resulting light-sensitive element was not more than 1 g.f. 
##STR167## 
Using the resulting light-sensitive element, a printing plate was prepared 
in the same manner as in Example 1. Printing was conducted using the 
printing plate thus-obtained in the same manner as in Example 1 and good 
results similar to those in Example 1 were obtained. 
EXAMPLE 5 
An amorphous silicon electrophotographic light-sensitive element was 
installed in an apparatus as shown in FIG. 2. The adhesive strength of the 
surface of the light-sensitive element was 200 gf. 
Impartation of releasability to the surface of light-sensitive element was 
conducted by dipping the light-sensitive element in a solution of the 
compound (S) according to the present invention (dip method) in the 
apparatus. Specifically, the light-sensitive element rotated at a 
circumferential speed of 10 mm/sec was brought into contact with a bath 
containing a solution prepared by dissolving 1.0 g of Compound (S-3) shown 
below in one liter of Isopar G for 7 seconds and dried using 
air-squeezing. The adhesive strength of the surface of the light-sensitive 
element thus-treated was 3 gf and the light-sensitive element exhibited 
good releasability. 
##STR168## 
The resulting light-sensitive element was charged to 700 V with a corona 
charge and exposed to light using a semiconductor laser having an 
oscillation wavelength of 780 nm at an irradiation dose on the surface of 
light-sensitive element of 25 erg/cm.sup.2 based on digital image data. 
The residual potential of the exposed areas was 120 V. The light-sensitive 
element was then developed with Liquid Developer (LD-2) having the 
composition shown below, while applying a bias voltage of 300 V to a 
development electrode to thereby electrodeposit the toner particles on the 
non-exposed areas. The light-sensitive element was then rinsed in a bath 
of Isopar H alone to remove stains on the non-image areas. The toner image 
was fixed by heating. 
Liquid Developer (LD-2) 
A copolymer of octadecyl methacrylate and methyl methacrylate (9:1 ratio by 
mole) as a coating resin and carbon black (#40 manufactured by Mitsubishi 
Kasei Corp.) were thoroughly mixed in a weight ratio of 2:1 and kneaded by 
a three-roll mill heated at 140.degree. C. A mixture of 12 g of the 
resulting kneading product, 4 g of a copolymer of styrene and butadiene 
(Sorprene 1205 manufactured by Asahi Kasei Kogyo K. K.) and 76 g of Isopar 
G was dispersed in a Dyno-mill. The toner concentrate obtained was diluted 
with Isopar G so that the concentration of solid material was 6 g per 
liter, and 1.times.10.sup.4 mol per liter of sodium dioctylsulfosuccinate 
was added thereto to prepare Liquid Developer (LD-2). 
On the surface of light-sensitive element bearing the toner image thereon 
installed on a drum, whose surface temperature was adjusted to 50.degree. 
C. and which was rotated at a circumferential speed of 10 mm/sec, 
Dispersion of Resin (A) (L-2) containing positively charged resin grains 
shown below was supplied using a slit electrodeposition device, while 
putting the light-sensitive element to earth and applying an electric 
voltage of 130 V to an electrode of the slit electrodeposition device to 
cause the resin grains to electrodeposite and fix, whereby a transfer 
layer having a thickness of 2.0 .mu.m was formed. 
______________________________________ 
Dispersion of Resin (A) (L-2) 
______________________________________ 
Resin Grain (ARW-1) 10 g 
(solid basis) 
Charge Control Agent (D-1) 
0.020 g 
Branched hexadecyl alcohol 
10 g 
(FOC-1600 manufactured by 
Nissan Chemical Industries, Ltd.) 
Isopar G up to make 1.0 
liter 
______________________________________ 
After heating the primary receptor same as in Example 2 at its surface 
temperature of 120.degree. C. the light-sensitive element 11 bearing the 
toner image and the transfer layer thereon, the surface temperature of 
which had been adjusted at 85.degree. C., was brought into contact with 
the primary receptor drum under the condition of a nip pressure of 3 
kgf/cm.sup.2 and a drum circumferential speed of 80 mm/sec, whereby the 
toner images were wholly transferred together with the transfer layer onto 
the primary receptor 20. 
Then, an aluminum substrate for FPD plate was introduced as a receiving 
material 30 on back-up roller for transfer 31 adjusted at 130.degree. C. 
and back-up roller for release 32 adjusted at 10.degree. C. and the 
aluminum substrate was brought into contact with the primary receptor of 
drum type, the surface temperature of which had been adjusted at 
85.degree. C. by temperature controller 17, under a nip pressure of 3 
kgf/cm.sup.2 and at a drum circumferential speed of 80 mm/sec whereby the 
toner image was transferred together with the transfer layer to the 
aluminum substrate. 
The printing plate precursor thus-obtained was further heated using a 
device (RICOH FUSER Model 592 manufactured by Ricoh Co., Ltd.) to fix the 
toner image portion. The printing plate precursor was observed visually 
using an optical microscope of 200 magnifications. It was found that the 
non-image areas had no stain and the image areas suffered no defects in 
high definition regions (i.e., cutting of fine lines and fine letters). 
Specifically, the toner image was easily transferred together with the 
transfer layer onto a receiving material by the heat-transfer process as 
described above and the toner image was not adversely affected by the heat 
treatment after the transfer. 
The printing plate precursor was immersed in Oil-Desensitizing Solution 
(E-2) having the composition shown below at 35.degree. C. for 30 seconds 
with moderate rubbing of the surface of precursor with a brush to remove 
the transfer layer, thoroughly washed with water and gummed to obtain a 
lithographic printing plate. 
______________________________________ 
Oil-Desensitizing Solution (E-2) 
______________________________________ 
PS plate processing solution 
143 g 
(DP-4 manufactured by Fuji Photo 
Film Co., Ltd.) 
N,N-Dimethylethanolamine 
100 g 
Distilled water up to make 1 
l 
(pH: 13.1) 
______________________________________ 
The printing plate was subjected to printing on neutral paper with various 
offset printing color inks using an offset printing machine (Oliver 94 
Model manufactured by Sakurai Seisakusho K. K.), and an aqueous solution 
(pH: 7.0) prepared by diluting dampening water for PS plate (SG-23 
manufactured by Tokyo Ink K. K.) 130-fold with distilled water, as 
dampening water. As a result, more than 60,000 prints with clear images 
free from background stains were obtained irrespective of the kind of 
color ink. 
As described above, for the purpose of maintaining sufficient adhesion of 
the toner image portion to a receiving material and increasing mechanical 
strength of toner image at the time of printing, a means for improving 
adhesion of toner image portion to a receiving material can be performed 
after the heat-transfer of toner image together with the transfer layer 
depending on the kind of liquid developer used for the formation of toner 
image. 
Good results similar to the above were also obtained using a flash fixing 
method or a heat roll fixing method as the means for improving adhesion of 
toner image portion. 
EXAMPLE 6 
A printing plate was prepared in the same manner as in Example 5, except 
for replacing the means for imparting releasability to the surface of 
light-sensitive element with the following method. Specifically, a 
metering roll having a silicone rubber layer on the surface thereof was 
brought into contact with a bath containing an oil of Compound (S-4) shown 
below on one side and with the light-sensitive element one the other side 
and they were rotated at a circumferential speed of 15 mm/sec for 20 
seconds. The adhesive strength of the surface of resulting light-sensitive 
element was 5 gf. 
##STR169## 
Further, a transfer roll having a styrenebutadiene layer on the surface 
thereof was placed between the metering roll dipped in the silicone oil 
bath of Compound (S-4) and the light-sensitive element, and the treatment 
was conducted in the same manner as above. Good releasability of the 
surface of light-sensitive element similar to the above was obtained. 
Moreover, Compound (S-4) 113 was supplied between the metering roll 112 and 
the transfer roll 111 as shown in FIG. 5 and the treatment was conducted 
in the same manner as above. Again, good result similar to the above was 
obtained. 
As a result of printing in the same manner as in Example 5, each printing 
plate exhibited the good performance similar to that in Example 5. 
EXAMPLE 7 
A printing plate was prepared and offset printing was conducted using the 
resulting printing plate in the same manner as in Example 5, except for 
replacing the means for imparting releasability to the surface of 
light-sensitive element with the following method. Specifically, an 
AW-treated felt (material: wool having a thickness of 15 mm and a width of 
20 mm) impregnated uniformly with 2 g of Compound (S-5), i.e., dimethyl 
silicone oil KF-96L-2.0 (manufactured by Shin-Etsu Silicone Co., Ltd.) was 
pressed under a pressure of 200 g on the surface of light-sensitive 
element and the light-sensitive element was rotated at a circumferential 
speed of 20 mm/sec for 30 seconds. The adhesive strength of the surface of 
light-sensitive element thus-treated was 6 gf. The results of printing 
were good similar to those in Example 5. 
EXAMPLE 8 
A printing plate was prepared and offset printing was conducted using the 
resulting printing plate in the same manner as in Example 5, except for 
replacing the means for imparting releasability to the surface of 
light-sensitive element with the following method. Specifically, a roller 
having a heating means integrated therein and covered with cloth 
impregnated with Compound (S-6), i.e., fluorine-containing surface active 
agent (Sarflon S-141 manufactured by Asahi Glass Co., Ltd.) was heated to 
a surface temperature of 60.degree. C., then brought into contact with the 
light-sensitive element and they were rotated at a circumferential speed 
of 20 mm/sec for 30 seconds. The adhesive strength of the surface of 
light-sensitive element thus-treated was 6 gf. The results of printing was 
good similar to those in Example 5. 
EXAMPLE 9 
A printing plate was prepared and offset printing was conducted using the 
resulting printing plate in the same manner as in Example 5, except for 
replacing the means for imparting releasability to the surface of 
light-sensitive element with the following method. Specifically, a 
silicone rubber roller comprising a metal axis covered with silicone 
rubber (manufactured by Kinyosha K. K.) was pressed on the light-sensitive 
element at a nip pressure of 600 gf/cm.sup.2 and rotated at a 
circumferential speed of 15 mm/sec for 10 seconds. The adhesive strength 
of the surface of light-sensitive element thus-treated was 18 gf/cm.sup.2. 
The results of printing was good similar to those in Example 5. 
EXAMPLES 10 TO 29 
Each printing plate was prepared and offset printing was conducted using 
each of the resulting printing plates in the same manner as in Example 1, 
except for using each of the resins (P) and/or resin grains (PL) shown in 
Table K below for a light-sensitive layer in place of 2 g of Resin (P-1) 
employed in Example 1. 
The image quality of prints obtained and printing durability of each 
printing plate were good similar to those in Example 1. 
TABLE K 
______________________________________ 
Resin (P) and/or 
Example Resin Grain (PL) 
Amount 
______________________________________ 
10 P-2 0.2 g 
11 PL-14 0.5 g 
12 P-6 0.3 g 
13 P-11 0.3 g 
14 PL-12 1.3 g 
15 P-19 0.2 g 
PL-3 1 g 
16 P-13 0.8 g 
17 P-16 1 g 
18 P-32 0.5 g 
19 P-17 0.4 g 
20 P-22 0.2 g 
PL-9 0.8 g 
21 P-28 0.4 g 
22 P-30 0.3 g 
23 PL-2 1.2 g 
24 P-34 0.3 g 
25 P-36 0.25 g 
26 P-31 0.1 g 
PL-15 0.8 g 
27 P-35 0.3 g 
28 PL-10 1.3 g 
29 P-38 0.25 g 
______________________________________ 
EXAMPLES 30 TO 40 
Each printing plate was prepared and offset printing was conducted using 
each of the resulting printing plates in the same manner as in Example 1 
except for using each of the compounds shown in Table L below in place of 
Resin (P-1), phthalic anhydride and o-chlorophenol employed in Example 1. 
The image quality of prints obtained and printing durability of each 
printing plate were good as those in Example 1. 
TABLE L 
______________________________________ 
Resin (P) 
Ex- or Resin Compound 
ample Grain (PL) 
Amount for Crosslinking 
Amount 
______________________________________ 
30 P-30 0.5 g Phthalic 0.2 g 
anhydride 
Zirconium 0.01 g 
acetylacetone 
31 P-22 0.6 g Gluconic acid 
0.008 g 
32 P-25 0.5 g N-Methylaminopro- 
0.25 g 
panol 
Dibutyltin 0.001 g 
dilaurate 
33 P-9 0.8 g N,N'-Dimethylpro- 
0.3 g 
panediamine 
34 P-7 0.6 g Propylene glycol 
0.2 g 
Tetrakis(2-ethylhex- 
0.008 g 
anediolato)titanium 
35 PL-3 2 g -- 
36 PL-15 0.9 g N,N-Dimethylpro- 
0.25 g 
panediamine 
37 P-13 0.7 g Divinyl adipate 
0.3 g 
2,2'-Azobis(isobuty- 
0.001 g 
ronitrile) 
38 P-14 0.8 g Propyltriethoxysilane 
0.01 g 
39 PL-1 1 g N,N-Diethylbutanedi- 
0.3 g 
amine 
40 P-5 1 g Ethylene diglycidyl 
0.2 g 
ether 
o-Chlorophenol 
0.001 g 
______________________________________ 
EXAMPLES 41 TO 58 
Each printing plate was prepared and offset printing was conducted using 
each of the resulting printing plates in the same manner as in Example 1 
except for using a total of 10 g of the resin grains shown in Table M 
below in place of a total of 10 g of Resin Grains (AR-4) and (AR-18) in a 
weight ratio of 1:1 employed in the electrodeposition coating method for 
the formation of transfer layer of Example 1. 
TABLE M 
______________________________________ 
Thickness of 
Resin Grain for 
Weight Transfer Layer 
Example Transfer Layer Ratio (um) 
______________________________________ 
41 AR-1/AR-19 2/3 4.5 
42 AR-2/AR-20 1/1 4.0 
43 AR-4/AR-21 1/1 4.0 
44 AR-5/AR-22 1/1 4.0 
45 AR-6/AR-23 7/3 5.0 
46 AR-7/AR-26 1/1 4.0 
47 AR-8/AR-32 3/7 4.0 
48 AR-9/AR-25 1/4 4.0 
49 AR-12/AR-24 1/1 4.0 
50 AR-13/AR-15 2/3 4.0 
51 AR-17/AR-18 1/1 4.0 
52 AR-11/AR-19 2/3 4.0 
53 ARW-2 3.0 
54 ARW-3/ARW-5 1/1 2.5 
55 ARW-4 2.0 
56 ARW-7 2.0 
57 ARW-8 2.0 
58 ARW-12/ARW-14 2/3 2.0 
______________________________________ 
The image quality of prints obtained and printing durability of each 
printing plate were good as those in Example 1. 
EXAMPLES 59 TO 61 
Each printing plate was prepared and offset printing was conducted using 
each of the resulting printing plates in the same manner as in Example 2 
except for using each of the resins (A) shown in Table N below in place of 
Resin (A-1) employed in the hot-melt coating method for the formation of 
transfer layer of Example 2. 
Good results similar to those in Example 2 were obtained. 
TABLE N 
__________________________________________________________________________ 
Example 
Resin (A) Constituting Transfer Layer 
__________________________________________________________________________ 
59 
##STR170## 
(A-4) Mw 8 .times. 10.sup.3, Tg 45.degree. C. 
60 A mixture of Resin (A-5) and Resin (A-6) in weight ratio of 1:1 
##STR171## 
(A-5) Mw 5 .times. 10.sup.3, Tg 25.degree. C. 
##STR172## 
(A-6) Mw 2 .times. 10.sup.4, Tg 40.degree. C. 
61 
##STR173## 
(A-7) Mw 2.5 .times. 10.sup.4 (Mw of dimethylsiloxane macromonomer 
portion 5 .times. 10.sup.3), Tg 40.degree. C. 
__________________________________________________________________________ 
EXAMPLES 62 TO 67 
Each printing plate was prepared and offset printing was conducted using 
each of the resulting printing plates in the same manner as in Example 3 
except for using paper prepared by coating each of the resins (A) shown in 
Table O below on release paper (San Release manufactured by Sanyo Kokusaku 
Pulp Co., Ltd.) to form a transfer layer having a thickness of 4 .mu.m in 
place of the paper having the transfer layer on Separate Shi employed in 
Example 3. 
With each printing plate, more than 60,000 prints with clear images free 
from background stains were obtained irrespective of the kind of color 
ink. 
TABLE O 
__________________________________________________________________________ 
Example 
Resin (A) Constituting Transfer Layer 
__________________________________________________________________________ 
62 A mixture of Resin (A-8) and Resin (A-9) in weight ratio of 3:2 
##STR174## 
(A-8) Mw 7 .times. 10.sup.4, Tg 20.degree. C. 
##STR175## 
(A-9) Mw 7 .times. 10.sup.3, Tg 55.degree. C. 
63 A mixture of Resin (A-10) and Resin (A-11) in weight ratio of 3:7 
##STR176## 
(A-10) Mw 6 .times. 10.sup.3, Tg 15.degree. C. 
##STR177## 
(A-11) Mw 1.5 .times. 10.sup.4, Tg 35.degree. C. 
64 A mixture of Resin (A-12) and Resin (A-13) in weight ratio of 1:1 
##STR178## 
(A-12) Mw 6 .times. 10.sup.3, Tg 15.degree. C. 
##STR179## 
(A-13) Mw 1 .times. 10.sup.4, Tg 55.degree. C. 
65 A double-layered structure of first layer adjacent to 
light-sensitive 
element composed of Resin (A-14) and second layer composed of 
Resin (A-5) in thickness ratio of 1:2 
##STR180## 
(A-14) Mw 2 .times. 10.sup.4 (Mw of macromonomer portion 8 .times. 
10.sup.3), Tg 60.degree. C. 
66 A double-layered structure of first layer adjacent to 
light-sensitive 
element composed of Resin (A-15) and second layer composed of 
Resin (A-12) in thickness ratio of 1:3 
##STR181## 
(A-15) Mw 1 .times. 10.sup.4 (Mw of macromonomer portion 5 .times. 
10.sup.3), Tg 65.degree. C. 
67 A double-layered structure of first layer adjacent to 
light-sensitive 
element composed of Resin (A-16) and second layer composed of 
Resin (A-17) in thickness ratio of 1:1 
##STR182## 
(A-16) Mw 8 .times. 10.sup.3, Tg 65.degree. C. 
##STR183## 
(A-17) Mw 9 .times. 10.sup.3, Tg 15.degree. C. 
__________________________________________________________________________ 
EXAMPLE 68 
A mixture of 100 g of photoconductive zinc oxide, 17 g of Binder Resin 
(B-4) having the structure shown below, 3 g of Binder Resin (B-5) having 
the structure shown below, 3 g of Resin (P-35), 0.01 g of uranine, 0.02 g 
of Rose Bengal, 0.01 g of bromophenol blue, 0.15 g of maleic anhydride and 
150 g of toluene was dispersed by a homogenizer (manufactured by Nippon 
Seiki K. K.) at a rotation of 9.times.10.sup.3 r.p.m. for 10 minutes. To 
the dispersion were added 0.02 g of phthalic anhydride and 0.001 g of 
o-chlorophenol, and the mixture was dispersed by a homogenizer at a 
rotation of 1.times.10.sup.3 r.p.m. for 1 minute. 
##STR184## 
The resulting dispersion was coated on base paper for a paper master having 
a thickness of 0.2 mm, which had been subjected to electrically conductive 
treatment and solvent-resistant treatment, by a wire bar at a coverage of 
25 g/m.sup.2, set to touch and heated in a circulating oven at 120.degree. 
C. for one hour. The adhesive strength of the surface of the thus-obtained 
electrophotographic light-sensitive element was 4 gf. 
The resulting light-sensitive element was charged to a surface potential of 
600 V in dark, exposed imagewise using a halogen lamp of 400 W for 7 
seconds, and subjected to development using Liquid Developer (LD-1) while 
applying a bias voltage of 100 V to a developing unit. Then, the element 
was rinsed in a bath of Isopar G, and the toner image was fixed by a heat 
roll. 
On the light-sensitive element bearing the toner image was provided a 
transfer layer of double-layered structure using the electrodeposition 
coating method in the following manner. 
Using Dispersion of Resin (A) (L-3) shown below, resin grains were 
electrodeposited while applying an electric voltage of 150 V to the 
light-sensitive element to form a first layer having a thickness of 2 
.mu.m. 
______________________________________ 
Dispersion of Resin (A) (L-3) 
Resin Grain (AR-1) 10 g 
(solid basis) 
Charge Control Agent (D-2) 
0.02 g 
shown below 
Banched Tetradecyl Alcohol 
8 g 
(FOC-1400 manfactured by 
Nissan Chemical Industries, Ltd.) 
Isopar G up to make 1 liter 
Charge Control Agent (D-2) 
##STR185## 
______________________________________ 
Then, using Dispersion of Resin (A) (L-4) shown below, resin grains were 
electrodeposited while applying an electric voltage of 200 V to the 
light-sensitive element to from a second layer having a thickness of 3 
.mu.m on the first layer. 
Dispersion of Resin (A) (L-4) 
Same as in Dispersion of Resin (A) (L-3) except for using 10 g of Resin 
Grain (AR-24) in place of 10 g of Resin Grain (AR-1). 
On the other hand, a heat roller which was a hollow roller having an 
infrared line heater integrated therein and being covered with silicone 
rubber having a thickness of 100 .mu.m adjusted its surface adhesive 
strength to 60 gf was used as a primary receptor, an the toner image was 
transferred together with the transfer layer from the light-sensitive 
element onto the primary receptor. 
The primary receptor having the transfer layer was then brought into 
contact with a sheet of Straight Master (manufactured by Mitsubishi Paper 
Mills, Ltd.) as a receiving material and they were passed between a pair 
of hollow rollers covered with silicone rubber each having an infrared 
lamp heater integrated therein. A surface temperature of each of the 
rollers was 90.degree. C., a nip pressure between the rollers was 3 
Kgf/cm.sup.2, and a transportation speed was 50 mm/sec. 
After cooling to room temperature, the Straight Master was separated from 
the primary receptor whereby the toner image was transferred together with 
the transfer layer to the Straight Master. 
As a result of visual evaluation of the image transferred on the Straight 
Master, it was found that the transferred image was almost same as the 
duplicated image on the light-sensitive element before transfer and 
degradation of image was not observed. Also, on the surface of the primary 
receptor after transfer, the residue of the transfer layer was not 
observed at all. These results indicated that the transfer had been 
completely performed. 
For comparison, an electrophotographic light-sensitive element was prepared 
in the same manner as described above except for eliminating 3 g of Resin 
(P-35). The adhesive strength of the surface thereof was more than 400 gf. 
Using the electrophotographic light-sensitive element for comparison, the 
electrophotographic process, formation of transfer layer and heat-transfer 
of transfer layer were conducted in the same manner as described above. It 
was found, however, that release at the interface between the surface of 
light-sensitive element and the transfer layer was not recognized at all. 
Then, the sheet of Straight Master having thereon the transfer layer was 
subjected to an oil-desensitizing treatment to prepare a printing plate 
and its printing performance was evaluated. Specifically, the sheet was 
immersed in Oil-Desensitizing Solution (E-3) having the composition shown 
below at 25.degree. C. for 30 seconds with moderate rubbing of the surface 
of sheet with a brush to remove the transfer layer and thoroughly washed 
with water to obtain a printing plate. 
______________________________________ 
Oil-Desensitizing Solution (E-3) 
______________________________________ 
Mercaptoethanesulfonic acid 
10 g 
Neosoap 5 g 
(manufactured by Matsumoto Yushi 
K.K.) 
N,N-Dimethylacetamide 
10 g 
Distilled water up to make 1 l 
Sodium hydroxide to adjust to pH 12.0 
______________________________________ 
The printing plate thus prepared was observed visually using an optical 
microscope of 200 magnifications. It was found that the non-image areas 
had no residual transfer layer, and the image areas suffered no defects in 
high definition regions (i.e., cutting of fine lines and fine letters). 
The printing plate was subjected to printing on neutral paper with various 
offset printing color inks using an offset printing machine (Ryobi 3200 
MCD Model manufactured by Ryobi Ltd.), and an aqueous solution (pH: 7.0) 
prepared by diluting dampening water for PS plate (SG-23 manufactured by 
Tokyo Ink K. K.) 130-fold with distilled water, as dampening water. As a 
result, more than 1,000 prints with clear images free from background 
stains were obtained irrespective of the kind of color ink. 
In a conventional system wherein an electrophotographic light-sensitive 
element utilizing zinc oxide is oil-desensitized with an oil-desensitizing 
solution containing a chelating agent as the main component under an 
acidic condition to prepare a lithographic printing plate, printing 
durability of the plate is in a range of several hundred prints without 
the occurrence of background stain in the non-image areas when neutral 
paper are used for printing or when offset printing color inks other than 
black ink are employed. Contrary to the conventional system, the method 
for preparation of a printing plate by an electrophotographic process 
according to the present invention can provide a printing plate having 
excellent printing performance in spite of using a zinc oxide-containing 
light-sensitive element. 
EXAMPLE 69 
5 g of 4,4'-bis(diethylamino)-2,2'-dimethyltriphenylmethane as an organic 
photoconductive substance, 4 g of Binder Resin (B-6) having the structure 
shown below, 0.4 g of Resin (P-27), 40 mg of Dye (D-1) having the 
structure shown below, and 0.2 g of Anilide Compound (C) having the 
structure shown below as a chemical sensitizer were dissolved in a mixed 
solvent of 30 ml of methylene chloride and 30 ml of ethylene chloride to 
prepare a solution for light-sensitive layer. 
##STR186## 
The resulting solution for light-sensitive layer was coated on a conductive 
transparent substrate composed of a 100 .mu.m thick polyethylene 
terephthalate film having a deposited layer of indium oxide thereon 
(surface resistivity: 10.sup.3 .OMEGA.) by a wire round rod to prepare a 
light-sensitive element having an organic light-sensitive layer having a 
thickness of about 4 .mu.m. The adhesive strength of the surface of 
light-sensitive element was 8 gf. 
The procedure same as in Example 1 was repeated except for using the 
resulting light-sensitive element in place of the light-sensitive element 
employed in Example 1 to prepare a printing plate. Using the printing 
plate, printing was conducted in the same manner as in Example 1. The 
prints obtained had clear images without the formation of background stain 
and printing durability of the printing plate was good similar to Example 
1. 
EXAMPLE 70 
A mixture of 5 g of a bisazo pigment having the structure shown below, 95 g 
of tetrahydrofuran and 5 g of a polyester resin (Vylon 200 manufactured by 
Toyobo Co., Ltd.) was thoroughly pulverized in a ball mill. The mixture 
was added to 520 g of tetrahydrofuran with stirring. The resulting 
dispersion was coated on a conductive transparent substrate used in 
Example 69 by a wire round rod to prepare a charge generating layer having 
a thickness of about 0.7 .mu.m. 
##STR187## 
A mixed solution of 20 g of a hydrazone compound having the structure shown 
below, 20 g of a polycarbonate resin (Lexan 121 manufactured by General 
Electric Co., Ltd.) and 160 g of tetrahydrofuran was coated on the 
above-described charge generating layer by a wire round rod, dried at 
60.degree. C. for 30 seconds and then heated at 100.degree. C. for 20 
seconds to form a charge transporting layer having a thickness of about 18 
.mu.m whereby an electrophotographic light-sensitive layer of a 
double-layered structure was prepared. 
##STR188## 
A mixed solution of 13 g of Resin (P-39) having the structure shown below, 
0.2 g of phthalic anhydride, 0.002 g of o-chlorophenol and 100 g of 
toluene was coated on the light-sensitive layer by a wire round rod, set 
to touch and heated at 120.degree. C. for one hour to prepare a surface 
layer for imparting releasability having a thickness of 1 .mu.m. The 
adhesive strength of the surface of the resulting light-sensitive element 
was 5 gf. 
##STR189## 
The resulting light-sensitive element was charged to a surface potential of 
500 V in dark and exposed imagewise using a helium-neon laser of 633 nm at 
an irradiation dose on the surface of the light-sensitive element of 30 
erg/cm.sup.2 followed by conducting the same procedure as in Example 1 to 
prepare a printing plate. As a result of offset printing using the 
resulting printing plate in the same manner as in Example 1, the printing 
plate exhibited the good performance similar to that in Example 1. 
EXAMPLES 71 TO 76 
Each printing plate was prepared and offset printing was conducted using 
the resulting printing plate in the same manner as in Example 5 except for 
employing each of the compounds (S) shown in Table P below in place of 1.0 
g/l of Compound (S-3) employed in Example 5. 
The results obtained were the same as those in Example 5. Specifically, the 
releasability was effectively imparted on the surface of light-sensitive 
element using each of the compounds (S). 
TABLE P 
__________________________________________________________________________ 
Example 
Compound (S) containing Fluorine Atom and/or Silicon 
(g/l) 
__________________________________________________________________________ 
71 (S-7) Polyether-modified silicone (TSF 4446 manufactured by Toshiba 
Silicone Co., Ltd.) 0.5 
##STR190## 
POA portion: polyoxyalkylene comprising ethylene oxide (EO) 
and propylene ocide (PO) (EP/PO: 100/0 by mole) 
72 (S-8) Carboxy-modified silicone (X-22-3701E manufactured by 
Shin-Etsu Silicone Co., Ltd.) 0.5 
##STR191## 
73 (S-9) Carbinol-modified silicone (X-22-176B manufactured by 
Shin-Etsu Silicone Co., Ltd.) 1 
##STR192## 
74 (S-10) Mercapto-modified silicone (X-22-167B manufactured by 
Shin-Etsu Silicone Co., Ltd.) 2 
##STR193## 
75 (S-11) 1.5 
##STR194## 
Mw 6 .times. 10.sup.3 
76 (S-12) 2 
##STR195## 
Mw 8 .times. 10.sup.3 (Mw of graft portion 3 .times. 10.sup.3) 
__________________________________________________________________________ 
EXAMPLES 77 TO 88 
An offset printing plate was prepared by subjecting some of the image 
receiving materials bearing the toner images together with the transfer 
layers (i.e., printing plate precursors) prepared in Examples 1 to 76 to 
the following oil-desensitizing treatment. Specifically, to 0.2 moles of 
each of the nucleophilic compounds shown in Table Q below, 100 g of each 
of the organic solvents shown in Table Q below, and 2 g of Newcol B4SN 
(manufactured by Nippon Nyukazai K. K.) was added distilled water to make 
one liter, and the solution was adjusted to a pH of 12.5. Each printing 
plate precursor was immersed in the resulting treating solution at a 
temperature of 35.degree. C. for one minute with moderate rubbing to 
remove the transfer layer. 
Printing was carried out using the resulting printing plate under the same 
conditions as in Example 1. Each plate exhibited good characteristics 
similar to those in Example 1. 
TABLE Q 
__________________________________________________________________________ 
Basis Example for 
Example 
Printing Plate Precursor 
Nucleophilic Compound 
Organic Solvent 
__________________________________________________________________________ 
77 Example 43 Sodium sulfite N,N-Dimethylformamide 
78 Example 44 Monoethanolamine 
Sulfolane 
79 Example 45 Diethanolamine Tetrahydrofuran 
80 Example 46 Thiomalic acid Ethylene glycol dimethyl 
ether 
81 Example 47 Thiosalicylic acid 
Benzyl alcohol 
82 Example 49 Taurine Ethylene glycol 
monomethyl ether 
83 Example 50 4-Sulfobenzenesulfinic acid 
Benzyl alcohol 
84 Example 51 Thioglycolic acid 
Tetramethylurea 
85 Example 54 2-Mercaptoethylphosphonic acid 
Dioxane 
86 Example 58 Cysteine N-Methylacetamide 
87 Example 61 Sodium thiosulfate 
Methyl ethyl ketone 
88 Example 66 Ammonium sulfite 
N,N-Dimethylacetamide 
__________________________________________________________________________ 
While the invention has been described in detail and with reference to 
specific embodiments thereof, it will be apparent to one skilled in the 
art that various changes and modifications can be made therein without 
departing from the spirit and scope thereof.