Planographic printing plate precursor and a method for producing a planographic printing plate

A planographig printing plate precursor which can be written by heat mode exposure of low energy, has excellent strength in image portions and blemishing resistance, can be developed with water, or can be installed in a printing machine as it is for conducting printing without requiring specific treatment such as wet developing treatment, rubbing and the like after writing of an image, and a method for producing the same, are provided. The planographic printing plate precursor of the present invention is obtained by laminating on a substrate having a hydrophilic surface a layer composed of a hydrophobic polymer which is made hydrophilic by heating and either a layer composed of a hydrophilic polymer compound having in the side chain at least one of alkylene oxide groups or functional groups selected from --COOR, --COOM, --SOR, --SO.sub.2 R, --SO.sub.3 R, --SOM, --SO.sub.2 M, --SO.sub.3 M, --OH, --NR.sup.22 R.sup.23 (wherein, R represent a hydrogen atom, alkyl group or aryl group, M represents a metal atom, R.sup.22 and R.sup.23 each independently represent a hydrogen atom, alkyl group or aryl group) or a layer of which exposed portions can be removed by heat mode exposure.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a planographic printing plate precursor 
and a method for producing a planographic printing plate. More 
particularly, the present invention relates to a planographic printing 
plate precursor which can be produced by scanning exposure based on 
digital signals, and a simple method for producing a planographic printing 
plate using the same. 
2. Description of Related Art 
A conventional planographic printing plate has been produced by exposing a 
planographic printing plate precursor to a light through a lith film, then 
removing non-image portions by dissolving them in a developing solution. 
Recently, digitalizing technologies have been spread widely in which image 
information is electronically processed, stored, and output using a 
computer, and various new image output methods making use of such 
digitizing technologies have been put into actual use. As a result, a 
computer-to-plate technology in which active radioactive light having a 
high directivity such as a laser light is scanned according to image 
information in the form of digitized data and printing plate is directly 
produced not via a lith film is eagerly desired, and it is an important 
technological problem to obtain a printing plate precursor suitable for 
this. On the other hand, in conventional production processes for a 
planographic printing plate, a process wherein removing non-image portions 
by dissolving them after exposure is indispensable. However, since the 
developing waste solution thereof is alkaline, a method for producing a 
printing plate which does not require such a wet treatment is eagerly 
awaited in today's industrial world where great importance is attached to 
protecting the environment. Thus, because of the already developed 
technologies for digitalizing image information and the necessity of 
environmental protection, planographic printing plate precursors which do 
not require wet treatment and can be produced in dry mode are keenly 
sought. 
Japanese Patent Application Laid-Open (JP-A) Nos. 5-77574, 4-125189, U.S. 
Pat. No. 5,187,047 and JP-A No. 62-195646 and the like disclose that after 
image formation, a film produced by sulfonation of polyolefins is used as 
a planographic printing plate precursor which does not require wet 
developing treatment, and hydrophilicity of the surface thereof is 
modified by thermal writing to create a plate precursor material which 
does not require developing treatment. In this system, an image is formed 
by de-sulfonating sulfone groups existing on the surface of photosensitive 
materials by thermal writing, therefore, developing treatment is not 
necessary, however, there is the drawback that noxious gas is generated in 
the writing. 
U.S. Pat. Nos. 5,102,771 and 5,225,316 suggest a sensitive material 
obtained by combining a polymer having an acid-sensitive group in the side 
chain and a photo acid generator, and propose a non-developing system. 
This plate precursor has the drawbacks that the hydrophilicity thereof is 
low, it is easily contaminated, and the durability of the plate precursor 
and clearness of the printed image are inferior, since the acid generated 
is a carboxylic acid. 
As image forming materials having radiation sensitivity suitable for the 
production of positive non-treated planographic printing plates, those 
described in JP-A No. 7-186562 are known using specific carboxylates or 
sulfonates as image forming materials. By using the image forming 
materials described in this publication, there can be obtained a 
planographic printing plate which can be developed with water giving a 
satisfactory print, however, if the energy in exposure is low, there is a 
tendency that the image forming material near the substrate does not 
become completely hydrophilic and the image forming material can not be 
removed completely, and accordingly, the resulting print is blemished. 
Further, as a method for producing a printing plate by scanning exposure, a 
method has been suggested utilizing active radioactive light having a high 
power density. In general, the recording mode by high power density 
exposure is called heat mode recording. The reason for this is that in a 
high power density exposure system, it is believed that photo energy 
absorbed by a sensitive material is often converted into heat, and the 
desired phenomenon is caused by the heat generated. A large part of the 
merit in the heat mode recording method resides in the potential 
possibility of simple treatment, dry treatment, and no-treatment. This is 
based on the fact that the phenomenon utilized for image recording of a 
heat mode sensitive material does not substantially occur by exposure to a 
light of normal strength or under normal environmental temperatures 
thereby negating the necessity for image fixing after exposure. 
As one preferable method of producing a planographic printing plate based 
on the heat mode recording, there is a method in which a hydrophobic image 
forming layer is provided on a hydrophilic substrate, the layer is 
subjected to image-wise heat mode exposure to alter the solubility and 
dispersibility of the hydrophobic layer, and where necessary, non-image 
portions are removed by wet development. As an example thereof, Japanese 
Patent Application Publication (JP-B) No. 46-27919 discloses a method in 
which a plate precursor comprising a hydrophilic substrate carrying 
thereon a recording layer which manifests improved solubility (a so-called 
positive), action by the effect of heat, and specifically a recording 
layer having a specific composition of saccharides, melamine-formaldehyde 
resin and the like, is subjected to heat mode recording to obtain a 
printing plate. However, heat mode scanning exposure sensitivity has been 
insufficient since none of the disclosed recording layers has satisfactory 
heat sensitivity. Further, it has been a practical problem that 
discrimination of hydrophobicity/hydrophilicity before and after exposure, 
namely a change in solubility is small. For example, for securing 
hydrophilicity after exposure, a recording layer is forced to become 
hydrophilic to a certain extent before exposure, and as a result, the ink 
receiving property of image portions of the resulting printing plate and 
strength in printing become insufficient. 
On the other hand, as another heat mode positive type plate precursor, U.S. 
Pat. No. 3,574,657 and JP-A No. 50-113307 suggest a plate precursor having 
a constitution in which a hydrophobic recording layer which can be removed 
by heat mode exposure is provided on a hydrophilic substrate. The 
principle of image recording of this plate precursor is based on the fact 
that the layer structure of a recording layer is destroyed by exposure, 
and as a result, the recording layer is removed in the exposure or 
printing processes, unlike the above-described plate production based on a 
change in the solubility and dispersibility of a recording layer in a heat 
mode solution type positive plate precursor. However, in a heat mode 
exposure removal type positive plate precursor, complete removal of a 
hydrophobic recording layer is difficult, and manifestation of sufficient 
hydrophilicity of non-image portions is difficult. On the other hand, 
there is the dilemma that when the thickness of a recording layer is 
decreased to enhance the removability thereof, a deterioration is caused 
in the strength of the image portions, and a printing plate having only a 
low printing resistance is obtained. 
SUMMARY OF THE INVENTION 
The present invention has been achieved in consideration of the 
above-described problems, and an object thereof is to provide a 
planographic printing plate precursor wherein after scanning exposure for 
a short period of time, exposed portions (non-image portions) have a high 
level of hydrophilicity and non-exposed portions (image portions) have a 
high level of hydrophobicity and strength. Namely, the object thereof is 
to provide a planographic printing plate precursor with which a 
planographic printing plate can be produced having excellent printing 
properties such as resistance to blemishes, printing durability and the 
like by scanning exposure for a short period of time. Another object 
thereof is to provide a planographic printing plate precursor with which a 
planographic printing plate can be produced also having excellent storage 
stability. Still another object thereof is to provide a method for 
producing a planographic printing plate which can be developed with water, 
or does not require additional wet treatment after exposure such as wet 
developing treatment, rubbing and the like after image writing. 
The present inventors have studied intensively to solve the above-described 
problems, and as a result, found that an excellent planographic printing 
plate precursor for heat mode exposure is obtained by using a recording 
layer comprising a polymer compound having in the side chain a functional 
group which generates a hydrophilic group by heating, and an infrared 
absorbing agent. As a result of studies, it has been found that a plate 
precursor is obtained which can provide a planographic printing plate of 
which image portions have extremely excellent strength and resistance to 
blemishes, by providing on a substrate a heat sensitive layer composed of 
the above-described polymer which can be made hydrophilic by heating and a 
layer having specific functions, thereby achieving the present invention. 
Namely, the planographic printing plate precursor of the present invention 
is obtained by laminating a layer composed of a hydrophobic polymer which 
can be made hydrophilic by heating (hereinafter, referred to as layer (b)) 
and either a layer composed of a hydrophilic polymer compound having at 
least one of alkylene oxide groups or having at least one functional 
groups selected from --COOR, --COOM, --SOR, --SO.sub.2 R, --SO.sub.3 R, 
--SOM, --SO.sub.2 M, --SO.sub.3 M, --OH, --NR.sup.22 R.sup.23 (wherein, R 
represents a hydrogen atom, alkyl group, or aryl group, M represents a 
metal atom, R.sup.22 and R.sup.23 each independently represent a hydrogen 
atom, alkyl group, or aryl group) (hereinafter, referred to as a layer 
(a)) or a layer of which exposed portions can be removed by heat mode 
exposure (hereinafter, referred to as layer (c)). 
In particular, the above-described problems are solved by (1) A 
planographic printing plate precursor obtained by laminating layer (a) and 
layer (b) in sequence on a substrate having a hydrophilic surface, 
(2) A planographic printing plate precursor obtained by laminating layer 
(b) and layer (c) in sequence on a substrate having a hydrophilic surface, 
or 
(3) A planographic printing plate precursor obtained by laminating layer 
(c) and layer (b) in sequence on a substrate having a hydrophilic surface. 
In the above-described planographic printing plate precursor (1), when 
layer (b) composed of a hydrophobic polymer compound which has a specific 
functional group and is made hydrophilic by heating (hereinafter, referred 
to where appropriate as a heat sensitive polymer compound) is made 
hydrophilic image-wise by a specific heating means, because of the 
existence of a layer composed of a hydrophilic polymer compound which has 
a specific functional group (referred to as layer (a) including a layer 
containing only (a-1) described below, a layer containing only (a-2) 
described below and a layer containing one or more of these) between the 
substrate and layer (b), exposed portions of layer (b) can be made 
hydrophilic with high heat efficiency without scattering to the substrate 
of heat due to the exposure, as a result, sensitivity is improved, and in 
addition, layer (b) hydrophilizated in non-image portions is solubilized 
with wetting water and does not remain on the substrate, therefore, the 
level of blemishing of the resulting print is extremely improved. 
The above-described planographic printing plate precursor (2) of the 
present invention can provide a planographic printing plate which has very 
high sensitivity and is excellent in strength and blemish resistance of 
image portions by providing an intermediate layer having a specific 
function (layer (b)) below layer (c) in a planographic printing plate 
precursor comprising a substrate of which at least the surface is 
hydrophilic carrying thereon a lipophilic recording layer which can be 
removed by irradiation with active radioactive light having high energy 
density. 
In the above-described planographic printing plate (3) light absorption and 
heat generation in heat mode exposure occur mainly in the intermediate 
layer (layer (c)) below heat sensitive layer (layer (b)), and the heat 
sensitive layer is made hydrophilic mainly from the substrate side. It is 
hypothesized that by this, hydrophilization of the heat sensitive layer 
becomes more complete. Further, the above-described planographic printing 
plate (3) manifests sufficient hydrophilicity even in the exposing energy 
range where hydrophilicity in non-image portions is insufficient on a 
conventional planographic printing plate precursor (a planographic 
printing plate precursor comprising a substrate carrying thereon only the 
intermediate layer of the present invention). Although the mechanism of 
this hydrophilicity manifestation is not clear, it is considered that 
providing a heat sensitive layer as an upper layer contributes to making 
the exposed portions hydrophilic. For example, it is considered that 
components in the intermediate layer and components in the heat sensitive 
layer may cause a certain chemical reaction and contribute to making the 
exposed portions hydrophilic. 
DETAILED DESCRIPTION OF THE INVENTION 
The above-described layer (a), layer (b) and layer (c) used in the 
planographic printing plate precursor of the present invention will be 
described below in detail. 
Layer (a) 
Layer (a) of the planographic printing plate precursor of the present 
invention is a layer mainly composed of a hydrophilic polymer compound 
(a-1) having in the side chain at least one functional group selected from 
--COOR, --COOM, --SOR, --SO.sub.2 R, --SO.sub.3 R, --SOM, --SO.sub.2 M, 
--SO.sub.3 M, --OH, --NR.sup.22 R.sup.23 (wherein, R represents a hydrogen 
atom, alkyl group or aryl group, M represents a metal atom, R.sup.22 and 
R.sup.23 each independently represents a hydrogen atom, alkyl group or 
aryl group) or a hydrophilic polymer compound (a-2) having at least one 
alkylene oxide group. 
The hydrophilicity of the hydrophilic polymer compound used in the present 
invention also includes the properties of water-solubility (meaning 
complete dissolving in water), pseudo water-solubility (meaning amphipatic 
properties, i.e. where the compound is water-soluble at a macroscopic 
level but contains non-soluble portions at a microscopic level), and water 
swelling (meaning the property where the compound swells with water but is 
not soluble in water). Namely, the compound contains a polymer which 
adsorbs or absorbs water under conditions of normal use or a polymer which 
is swollen with or dissolved in water. As compounds which lie within the 
above-described definition, a hydrophilic polymer compound (a-1) having at 
least one functional group selected from --COOR, --COOM, --SOR, --SO.sub.2 
R, --SO.sub.3 R, --SOM, --SO.sub.2 M, --SO.sub.3 M, --OH, --NR.sup.22 
R.sup.23 (wherein, R represents a hydrogen atom, alkyl group or aryl 
group, M represents a metal atom, R.sup.22 and R.sup.23 each independently 
represent a hydrogen atom, alkyl group, or aryl group) and a hydrophilic 
polymer compound (a-2) having in the molecule an alkylene oxide group are 
listed, and known natural polymer compounds or synthetic polymer compounds 
containing these functional groups can be used. 
Examples of synthetic polymer compounds as the hydrophilic polymer compound 
(a-1) having at least one functional group selected from --COOR, --COOM, 
--SOR, --SO.sub.2 R, --SO.sub.3 R, --SOM, --SO.sub.2 M, --SO.sub.3 M, 
--OH, --NR.sup.22 R.sup.23 (wherein, R represents a hydrogen atom, alkyl 
group or aryl group, M represents a metal atom, R.sup.22 and R.sup.23 each 
independently represent a hydrogen atom, alkyl group or aryl group) 
include the following compounds: carboxylate salt-based copolymers, 
N-vinylcarboxylic amide-based copolymers, sulfonate salt-based copolymers, 
vinylpyrrolidone-based copolymers, polyvinyl alcohol, aqueous urethane 
resins, water-soluble polyesters, hydroxyethyl(meth)acrylate-based 
polymers, poly(vinylmethyl ether-co-maleic anhydride), polyethylene glycol 
di(meth)acrylate-based cross-linked polymers, polypropylene glycol di 
(meth)acrylate-based cross-linked polymers, and the like. 
As the carboxylate salt-based copolymer having --COOR or --COOM in the side 
chain, there are listed saponification reaction products of carboxylic 
acid-based copolymers containing as a monomer component an 
.alpha.,.beta.-unsaturated compound having in the molecule one or two 
carboxyl groups or functional groups which can be converted to carboxyl 
groups such as a carboxyl group, carboxylate salt, carboxylic amide, 
carboxylic imide, carboxylic anhydride and the like. 
Specific examples of the .alpha.,.beta.-unsaturated compound include 
acrylic acid, methacrylic acid, acrylates, methacrylates, acrylic amides, 
methacrylic amides, maleic anhydride, maleic acid, maleic amides, maleic 
imides, itaconic acid, crotonic acid, fumaric acid, mesaconic acid and the 
like. 
Specific examples of the acrylates include methyl acrylate, ethyl acrylate, 
(n- or i-)propyl acrylate, (n-, i-, sec- or t-)butyl acrylate, amyl 
acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, chloroethyl acrylate, 
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 5-hydroxypentyl 
acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane 
monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl 
acrylate, chlorobenzyl acrylate, hydroxybenzyl acrylate, hydroxyphenetyl 
acrylate, dihydroxyphenetyl acrylate, furfuryl acrylate, 
tetrahydrofurfuryl acrylate, phenyl acrylate, hydroxyphenyl acrylate, 
chlorophenyl acrylate, sulfamoylphenyl acrylate, 
2-(hydroxyphenylcarbonyloxy)ethyl acrylate, and the like. 
Specific examples of the methacrylates include methyl methacrylate, ethyl 
methacrylate, (n- or i-)propyl methacrylate, (n-, i-, sec- or t-)butyl 
methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate, 
dodecylmethacrylate, chloroethyl methacrylate, 2-hydroxyethyl 
methacrylate, 2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, 
cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane 
monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, 
benzyl methacrylate, methoxybenzyl methacrylate, chlorobenzyl 
methacrylate, hydroxybenzyl methacrylate, hydroxyphenetyl methacrylate, 
dihydroxyphenetyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl 
methacrylate, phenyl methacrylate, hydroxyphenyl methacrylate, 
chlorophenyl methacrylate, sulfamoylphenyl methacrylate, 
2-(hydroxyphenylcarbonyloxy)ethyl methacrylate, and the like. 
Specific examples of the acrylamides include acrylamide, 
N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, 
N-butylacrylamide, N-benzylacrylamide, N-hydroxyethylacrylamide, 
N-phenylacrylamide, N-tolylacrylamide, N-(hydroxyphenyl)acrylamide, 
N-(sulfamoylphenyl)acrylamide, N-(phenylsulfonyl)acrylamide, 
N-(tolylsulfonyl)acrylamide, N,N-dimethylacrylamide, 
N-methyl-N-phenylacrylamide, N-hydroxyethyl-N-methylacrylamide, and the 
like. 
Specific examples of the maleic amides include maleic amide, N-methylmaleic 
amide, N-ethylmaleic amide, N-propylmaleic amide, N-butylmaleicamide, 
N-benzylmaleic amide, N-hydroxyethylmaleic amide, N-phenylmaleic amide, 
N-tolylmaleic amide, N-(hydroxyphenyl)maleic amide, 
N-(sulfamoylphenyl)maleic amide, N-(phenylsulfonyl)maleic amide, 
N-(tolylsulfonyl)maleic amide, N,N-dimethylmaleic amide, 
N-methyl-N-phenylmaleic amide, N-hydroxyethyl-N-methylmaleic amide, and 
the like. 
Specific examples of the maleic imides include maleic imide, N-methylmaleic 
imide, N-ethylmaleic imide, N-propylmaleic imide, N-butylmaleic imide, 
N-benzylmaleic imide, N-hydroxyethylmaleic imide, N-phenylmaleic imide, 
N-tolylmaleic imide, N-(hydroxyphenyl)maleic imide, 
N-(sulfamoylphenyl)maleic imide, N-(phenylsulfonyl)maleic imide, 
N-(tolylsulfonyl)maleic imide, and the like. 
The carboxylate salt-based copolymers used in the present invention may be 
a homopolymer of the above-described .alpha.,.beta.-unsaturated compound, 
or a copolymer with another copolymerizable monomer providing it has 
hydrophilicity necessary to the present invention. Examples of the other 
copolymerizable monomer include known monomers such as ethylene, 
propylene, isobutylene, 1-butylene, diisobutylene, methyl vinyl ether, 
acrylonitrile, vinyl esters, styrenes and the like. 
Specific examples of the vinyl esters include vinyl acetate, vinyl 
butyrate, vinyl benzoate, and the like. 
Specific examples of the styrenes include styrene, methylstyrene, 
dimethylstyrene, trimethylstyrene, ethylstyrene, propylstyrene, 
cyclohexylstyrene, chloromethylstyrene, trifluoromethylstyrene, 
ethoxymethylstyrene, acetoxymethylstyrene, methoxystyrene, 
dimethoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, 
iodostyrene, fluorostyrene, carboxystyrene, and the like. 
When combined with another monomer, the content of an 
.alpha.,.beta.-unsaturated compound containing a carboxyl group or a group 
which can be converted into a carboxyl group is usually 10 mol % or more, 
and preferably 40 mol % or more in the whole monomer components. 
A polymer contained as the .alpha.,.beta.-unsaturated compound containing a 
carboxyl group or a group which can be converted to a carboxyl group can 
be produced using known methods (see, e.g., POLYMER CHEMISTRY, vol. 7, p. 
142 (1950)). Namely, these carboxylate salt copolymers may be any of 
random polymers, block polymers, graft polymers and the like, however, 
random polymers, appropriately selected depending on the polymerization 
method, are preferable. For example, they are synthesized by radical 
polymerization using polymerization initiators such as peroxides such as 
di-t-butyl peroxide, benzoyl peroxide and the like, persulfate salts such 
as ammoniumpersulfate and the like, azo compounds such as 
azobisisobutyronitrile and the like, as well as other compounds. As the 
polymerization method, solution polymerization, emulsion polymerization, 
suspension polymerization and the like are adopted. 
Examples of suitable solvents used in synthesizing these carboxylate 
salt-based copolymers include tetrahydrofuran, ethylene dichloride, 
cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene 
glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl 
acetate, diethylene glycol dimethyl ether, 1-methoxy-2-propanol, 
1-methoxy- 2-propyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, 
toluene, ethyl acetate, methyl lactate, ethyl lactate, dimethylsulfoxide, 
water and the like. These solvents are used alone or in combinations of 
two or more. 
The degree of polymerization of these carboxylate salt-based copolymers is 
not particularly restricted. 
The polymers or copolymers as explained above are preferably saponified in 
the presence of an alkaline catalyst. As the solvent used in the 
saponification, water, alcohol and aqueous alcohol solution are 
preferable. As the catalyst used for the saponification reaction, known 
alkaline catalysts are used, and particularly, alkaline metal hydroxides 
such as sodium hydroxide, potassium hydroxide and the like are suitable. 
The saponification reaction is accomplished by dissolving or dispersing 
the above-described polymer or copolymer in the above-described solvent, 
adding to this an alkaline catalyst and stirring the mixture for 1 to 10 
hours at 20 to 80.degree. C. 
In the saponification reaction product in the present invention, the salt 
type thereof can be varied at will according to known methods. As 
salt-forming substances usually used, there are listed sodium hydroxide, 
potassium hydroxide, ammonium hydroxide, monomethylamine, dimethylamine, 
trimethylamine, monoethylamine, diethylamine, triethylamine, 
monoisopropylamine, diisopropylamine, triisopropylamine, monoethanolamine, 
diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, 
triisopropanolamine, N,N-dimethylethanolamine, 
N,N-dimethylisopropanolamine, cyclohexylamine, benzylamine, aniline, 
pyridine and the like. 
Further, polyvalent metal salts of alkaline earth metal salts such as 
magnesium, potassium and the like can also be added in the form of a mixed 
salt with the above-described salts. 
Specific examples of the carboxylate salt-based copolymers include 
compounds such as saponification reaction products of acrylic acid 
polymers, methacrylic acid polymers or methyl acrylate polymers, 
saponification reaction products of methacrylic amide copolymers, 
saponification reaction products of acrylic acid/methacrylic acid 
copolymers, maleic acid/styrene copolymers or methyl acrylate/vinyl 
acetate copolymers, and the like. 
The term N-vinylcarboxylic amide-based copolymer means a copolymer 
containing as an essential repeating unit N-vinylcarboxylic amide 
(hereinafter, abbreviated as NVA) represented by the following general 
formula (6) (hereinafter, abbreviated as an NVA-based copolymer). 
##STR1## 
wherein, R.sup.24 represents a hydrogen atom or an alkyl group having 1 to 
4 carbon atoms, R.sup.25 represents a hydrogen atom, a methyl group, or 
phenyl group, and R.sup.26 represents a hydrogen atom or a straight chain 
or branched chain alkyl group. 
Specific examples of the NVA include, but are not limited to, 
N-vinylformamide, N-vinylpropionic amide, N-vinylbenzoic amide, 
N-methyl-N-vinylbenzoic amide, N-phenyl-N-vinylacetamide, 
N-phenyl-N-vinylbenzoic amide, and the like. 
The N-vinylcarboxylic amide-based copolymer preferably used in the present 
invention preferably contains as a copolymer unit an 
.alpha.,.beta.-unsaturated compound having in the molecule one or two 
carboxyl groups or functional groups which can be derived into a carboxyl 
group such as a carboxyl group, carboxylate salt, carboxylic amide, 
carboxylic imide, carboxylic anhydride and the like. 
Specific examples of the .alpha.,.beta.-unsaturated compound include 
acrylic acid, methacrylic acid, acrylates, methacrylates, acrylic amides, 
methacrylic amides, maleic anhydride, maleic acid, maleic amides, maleic 
imides, itaconic acid, crotonic acid, fumaric acid, mesaconic acid, and 
the like. 
As the specific examples of the acrylates, methacrylates, acrylic amides, 
methacrylic amides, maleic amides and maleic imides, the compounds 
described above are listed. 
The NVA-based copolymer preferably used in the present invention can 
contain another copolymerizable monomer providing it has the 
hydrophilicity necessary to the present invention. Examples of another 
copolymerizable monomer include known monomers such as ethylene, 
propylene, isobutylene, 1-butylene, diisobutylene, methyl vinyl ether, 
acrylonitrile, vinyl esters, styrenes and the like. 
As specific examples of the vinyl esters and styrenes, the compounds 
described above are listed. 
The NVA-based copolymer is usually prepared by radical polymerization. 
These NVA-based copolymers may be any polymer such as random polymers, 
block polymers, graft polymers and the like, and a random polymer which 
can be produced by known methods is preferable (see, e.g., POLYMER 
CHEMISTRY, vol. 7, p. 142 (1950)). Namely, these carboxylate salt-based 
copolymers may be any of random polymers, block polymers, graft polymers 
and the like, however, random polymers which are appropriately selected 
depending on the polymerization method are preferable. For example, they 
are synthesized by radical polymerization using polymerization initiators 
such as peroxides such as di-t-butyl peroxide, benzoyl peroxide and the 
like, persulfate salts such as ammonium persulfate and the like, azo 
compounds such as azobisisobutyronitrile and the like, as well as other 
compounds. As the polymerization method, solution polymerization, emulsion 
polymerization, suspension polymerization and the like are adopted. 
Examples of suitable solvents used in synthesizing these NVA-based 
copolymers include tetrahydrofuran, ethylene dichloride, cyclohexanone, 
methyl ethyl ketone, acetone, methanol, ethanol, ethylene glycol 
monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, 
diethylene glycol dimethyl ether, 1-methoxy-2-propanol, 1-methoxy-2-propyl 
acetate, N,N-dimethylformamide, N,N-dimethylacetamide, toluene, ethyl 
acetate, methyl lactate, ethyl lactate, dimethylsulfoxide, water and the 
like. These solvents are used alone or in combination of two or more. 
The degree of polymerization of these NVA-based copolymers is not 
particularly restricted. 
Specific examples of the NVA-based copolymer include the following 
polymers: 
Poly(N-vinylacetamide), N-vinylacetamide/(meth) acrylic acid copolymer and 
partially or completely neutralized compound thereof (partially or 
completely neutralized compound means a copolymer in which a portion of 
all the hydrogen ions in a polymerizable functional group such as 
carboxylic acid, sulfonic acid, phosphoric acid and the like in the 
copolymer are substituted by an alkaline metal salt such as sodium, 
potassium and the like or an alkaline metal earth salt such as calcium, 
barium and the like), N-vinylacetamide/crotonic acid copolymer and 
partially or completely neutralized compounds thereof, 
N-vinylacetamide/maleic acid copolymer and partially or completely 
neutralized compounds thereof, N-vinylacetamide/fumaric acid copolymer and 
partially or completely neutralized compounds thereof, 
N-vinylacetamide/citraconic acid copolymer and partially or completely 
neutralized compounds thereof, N-vinylacetamide/cinnamic acid copolymer 
and partially or completely neutralized compounds thereof, 
N-vinylacetamide/vinylsulfonic acid copolymer and partially or completely 
neutralized compounds thereof, N-vinylacetamide/maleic anhydride copolymer 
and partially or completely neutralized compounds thereof, 
N-vinylacetamide/itaconic acid copolymer and partially or completely 
neutralized compounds thereof, N-vinylacetamide/aconitic acid copolymer 
and partially or completely neutralized compounds thereof, 
N-vinylacetamide/3-butenoic acid copolymer and partially or completely 
neutralized compounds thereof, N-vinylacetamide/4-pentenoic acid copolymer 
and partially or completely neutralized compounds thereof, 
N-vinylacetamide/arylsulfonic acid copolymer and partially or completely 
neutralized compounds thereof, N-vinylacetamide/methallylsulfonic acid 
copolymer and partially or completely neutralized compounds thereof, 
N-vinylacetamide/allylphosphoric acid copolymer and partially or 
completely neutralized compounds thereof, N-vinylacetamide/carboxyethyl 
acrylate copolymer and partially or completely neutralized compounds 
thereof, N-vinylacetamide/2-acryloylethylphosphoric acid copolymer and 
partially or completely neutralized compounds thereof, 
N-vinylacetamide/3-acryloylpropylphosphoric acid copolymer and partially 
or completely neutralized compounds thereof, 
N-vinylacetamide/8-methacryloyloctylphosphoric acid copolymer and 
partially or completely neutralized compounds thereof, 
N-vinylacetamide/2-acrylamide-n-propanesulfonic acid copolymer and 
partially or completely neutralized compounds thereof, 
N-vinylacetamide/2-acrylamide-n-octanesulfonic acid copolymer and 
partially or completely neutralized compounds thereof, 
N-vinylacetamide/2-acrylamide-2-methylpropanesulfonic acid copolymer and 
partially or completely neutralized compounds thereof, and the like. 
As the sulfonate salt-based copolymer having in the side chain --SO.sub.3 R 
or --SO.sub.3 M, there are listed copolymers containing as the monomer 
component an unsaturated compound having in the molecule a sulfonate salt 
or a functional group which can be derived into a sulfonate salt such as a 
sulfonic amide, sulfonate and the like, or saponification reaction 
products of the copolymers. As specific examples of such unsaturated 
compounds, the following compounds are listed. 
##STR2## 
Homopolymers obtained by using only one of these monomers may be used, 
however, copolymers obtained by using two or more of them and copolymers 
of these monomers with other monomers may also be used providing they 
manifest the hydrophilicity necessary to the present invention. 
Examples of the copolymerizable other monomer include known monomers such 
as ethylene, propylene, isobutylene, 1-butylene, diisobutylene, methyl 
vinyl ether, acrylonitrile, acrylates, methacrylates, acrylamides, 
methacrylamides, vinyl esters, styrenes and the like. 
Specific examples of the acrylates, methacrylates, acrylamides, 
methacrylamides, vinyl esters and styrenes include are as described above. 
The polymer containing as a monomer an unsaturated compound containing a 
sulfonate salt or a group which can be converted to this is usually 
prepared by radical polymerization. These sulfonate salt-based copolymers 
may be any polymer such as random polymers, block polymers, graft polymers 
and the like, and a random polymer is preferable. They can be produced by 
known methods (see, e.g., POLYMER CHEMISTRY, vol. 7, p. 142 (1950)). 
Namely, these carboxylate salt copolymers may be any of random polymers, 
block polymers, graft polymers and the like, however, preferably, they are 
random polymers, and are appropriately selected depending on the 
polymerization method. For example, they are synthesized by radical 
polymerization using polymerization initiators such as peroxides such as 
di-t-butyl peroxide, benzoyl peroxide and the like, persulfate salts such 
as ammonium persulfate and the like, azo compounds such as 
azobisisobutyronitrile and the like, as well as other compounds. As the 
polymerization method, solution polymerization, emulsion polymerization, 
suspension polymerization and the like are adopted. 
Examples of suitable solvents used in synthesizing these sulfonate 
salt-based copolymers include tetrahydrofuran, ethylene dichloride, 
cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene 
glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl 
acetate, diethylene glycol dimethyl ether, 1-methoxy-2-propanol, 
1-methoxy-2-propyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, 
toluene, ethyl acetate, methyl lactate, ethyl lactate, dimethylsulfoxide, 
water and the like. These solvents are used alone or in combinations of 
two or more. 
The degree of polymerization of these sulfonate salt-based copolymers is 
not particularly restricted. 
The copolymers as explained above are preferably saponified in the presence 
of an alkaline catalyst. As the solvent used in the saponification, water, 
alcohol and aqueous alcohol solution are preferable. As the catalyst used 
for the saponification reaction, known alkaline catalysts are used, and 
particularly, alkaline metal hydroxides such as sodium hydroxide, 
potassium hydroxide and the like are suitable. The saponification reaction 
is accomplished by dissolving or dispersing the above-described polymer or 
copolymer in the above-described solvent, adding to this an alkaline 
catalyst and stirring the mixture for 1 to 24 hours at 20 to 80.degree. C. 
In the saponification reaction product in the present invention, the type 
of salt can be varied at will according to known methods. As salt-forming 
substances usually used, there are listed sodium hydroxide, potassium 
hydroxide, ammonium hydroxide, monomethylamine, dimethylamine, 
trimethylamine, monoethylamine, diethylamine, triethylamine, 
monoisopropylamine, diisopropylamine, triisopropylamine, monoethanolamine, 
diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, 
triisopropanolamine, N,N-dimethylethanolamine, 
N,N-dimethylisopropanolamine, cyclohexylamine, benzylamine, aniline, 
pyridine and the like. 
Further, polyvalent metal salts of alkaline earth metal salts such as 
magnesium, potassium and the like can also be added in the form of a mixed 
salt with the above-described salts. 
Specific examples of the sulfonate salt-based copolymers include the 
following polymers: 
##STR3## 
Examples of polymers having preferable hydrophilicity for sufficiently 
manifesting the effect of the present invention in the above-described 
hydrophilic polymer compound include carboxylate salt-based copolymers, 
NVA-based copolymers, sulfonate salt-based copolymers and polyvinyl 
alcohol, and more preferably carboxylate salt-based copolymers, NVA-based 
copolymers and sulfonate salt-based copolymers. 
Among the carboxylate salt-based copolymers, preferable are polymers or 
copolymers with acrylic acid and methacrylic acid, and copolymers of an 
a-olefin or vinyl compound with maleic anhydride, and more preferable are 
saponification reaction products of a vinyl ester with a (meth)acrylate 
copolymer (in the following explanation, (meth)acrylic acid is the 
abbreviation of acrylic acid and/or methacrylic acid). In this copolymer, 
it is preferable that the (meth)acrylate component occupies 20 to 80 mol % 
of the copolymer, and it is more preferable that the component occupies 30 
to 70 mol % of the copolymer for satisfying simultaneously water 
absorption and mechanical strength requirements of the layer (a). 
Among the NVA-based copolymers, preferable are copolymers of NVA with a 
carboxylic acid such as acrylic acid, methacrylic acid, maleic anhydride 
and the like, and from the viewpoints of water absorption and durability, 
the NVA unit occupies preferably 10 mol % or more, and more preferably 40 
mol % or more of the whole monomer. 
Further, preferable as the sulfonate salt-based copolymer are polymers and 
copolymers of styrenesulfonate salts and styrenesulfonates, copolymers of 
styrenesulfonate salts or styrenesulfonates with (meth)acrylic acid, 
(meth)acrylate, vinyl ester and/or maleic anhydride, or saponification 
reaction products of these polymers and copolymers. From the viewpoints of 
water absorption and durability, the styrenesulfonate salt or 
styrenesulfonate occupies preferably 20 mol % or more, and more preferably 
50 mol % or more of the whole monomers. 
Examples of natural polymer compounds as the hydrophilic polymer compounds 
having in the side chain a functional group selected from --COOR, --COOM, 
--SOR, --SO.sub.2 R, --SO.sub.3 R, --SOM, --SO.sub.2 M, --SO.sub.3 M, 
--OH, --NR.sup.22 R.sup.23 include starch-styrenesulfonic acid-based graft 
polymers, starch-vinylsulfonic acid-based graft polymers, 
starch-acrylamide-based graft polymers, carboxylated methylcellulose, 
cellulose-styrenesulfonic acid-based graft polymers, 
carboxymethylcellulose-based cross-linked compounds, and the like. 
The hydrophilic polymer compound having an alkylene oxide group in the 
molecule (a-2) used in the present invention is not particularly 
restricted providing it has an alkylene oxide group in the main chain or 
side chain, specific examples thereof include polyethylene oxide, 
poly(ethylene oxide-co-propylene oxide) and the like, and examples of the 
natural polymer compound include starch-acrylonitrile-based graft polymer 
hydrolyzate, starch-acrylic acid-based graft polymers, methylcellulose, 
hydroxypropylmethylcellulose, hydroxyethylcellulose, xanthic acid 
cellulose, cellulose-acrylonitrile-based graft copolymers, hyarulonic 
acid, agarose, collagen, milk casein, acid casein, rennet casein, ammonia 
casein, potassium casein, borax casein, glue, gelatin, gluten, soy bean 
protein, alginate, ammonium alginate, potassium alginate, sodium alginate, 
gum arabic, tragacanth gum, karaya gum, guar gum, locustbean gum, Irish 
moss, soy bean lecithin, pectinic acid, starch, carboxylated starch, agar, 
dextrin, mannan, and the like. The layer (a-1), (a-2) or (a) in the 
present invention may optionally contain compounds described below as 
constituent components in addition to the above-described hydrophilic 
polymer compounds within a range wherein the effect of the present 
invention is not lost. 
Into the layer (a) of the planographic printing plate of the present 
invention, there can be added, for enhancing stability in the printing 
conditions, nonionic surfactants as described in JP-A Nos. 62-251740 and 
3-208514, and ampholytic surfactants as described in JP-A Nos. 59-121044 
and 4-13149. 
Specific examples of the nonionic surfactant include sorbitantristearate, 
sorbitanmonopalmitate, sorbitantrioleate, stearic acid monoglyceride, 
polyoxyethylenenonyl phenyl ether, and the like. 
Specific examples of the ampholytic surfactant include 
alkyldi(aminoethyl)glycine, alkylpolyaminoethylglycine hydrochloride, 
2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, 
N-tetradecyl-N,N-betaine type (for example, trade name: AMOGEN K, 
manufactured by Dai-itchi Kogyo Siyaku. Co., Ltd.), and the like. 
The proportion of the above-described nonionic surfactant and ampholytic 
surfactant based on the total weight of solid components of this 
hydrophilic layer is preferably from 0.05 to 15% by weight, and more 
preferably from 0.1 to 5% by weight. 
A photo-thermal conversion material is preferably added to layer (a). 
Various infrared ray absorbing dyes can be preferably used as the 
photo-sensitive conversion material. The dye I represented by the 
following formula is especially preferable. 
##STR4## 
The layer (a) of the planographic printing plate of the present invention 
can be produced usually by dissolving the above-described components in a 
solvent and coating the mixture on a suitable substrate. 
Examples of the solvent herein used include, but are not limited to, 
ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, 
ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 
2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, 
methyl lactate, ethyl lactate, N,N-dimethylacetamide, 
N,N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, 
dimethylsulfoxide, sulfolane, Y-butyrolactone, toluene, water, and the 
like. 
These solvents are used alone or in a mixture. The concentration of the 
above-described components (whole solid components) in the solvent is 
preferably from 1 to 50% by weight. 
Various methods can be used for the coating, and examples thereof include 
bar coater coating, rotation coating, spray coating, curtain coating, dip 
coating, air knife coating, blade coating, roll coating and the like. 
Into the layer (a) of the planographic printing plate of the present 
invention, there can be added surfactants for enhancing coatability, for 
example, fluorine-based surfactants as described in JP-A No. 62-170950. 
The preferable amount added is from 0.01 to 1% by weight, and more 
preferably from 0.05 to 0.5% by weight based on the total weight of solid 
components in the layer (a). 
Layer (a) manifests functions of securing a hydrophilic surface in exposed 
portions and improving heat efficiency, and therefore, the amount coated 
(solid component) on the substrate obtained after coating and drying is, 
in general, preferably from 0.5 mg/m.sup.2 to 1.0 g/m.sup.2, more 
preferably from 1 mg/m.sup.2 to 500 g/m.sup.2, and most preferably from 2 
mg/m.sup.2 to 300 g/m.sup.2. 
When the amount coated is less than 0.5 g/m.sup.2, the effect for improving 
heat efficiency becomes insufficient, and even if the mixture is coated at 
an amount over 1.0 g/m.sup.2, improvement in the effect is not recognized, 
on the contrary, printing durability unpreferably deteriorates. 
Layer (b) 
Layer (b) of the planographic printing plate precursor of the present 
invention changes to hydrophilic from hydrophobic and the solubility and 
dispersibility thereof the water increase by the action of heat. The 
change in hydrophobicity/hydrophilicity can be confirmed by for example 
solubility, dispersibility and wetting property (contact angle) in water. 
For example, a heat sensitive layer of which the contact angle against a 
water drop in air decreases by 10.degree. or more by heating is 
preferable, and 40.degree. or more is more preferable. Particularly 
preferably, the heat sensitive layer is essentially insoluble in water 
before heating, and becomes soluble or dispersible in water by heating. 
As preferable examples of the layer (b) having this property, there are 
listed polymers which can generate a sulfonic acid in the side chain by 
heating (hereinafter, referred to as "sulfonic acid generating polymers") 
and polymers which can generate a carboxylic acid in the side chain by 
heating (hereinafter, referred to as "carboxylic acid generating 
polymers"). These polymers, before heating, have a hydrophobic sulfonate 
or carboxylate structure and carry in the side chain a group which is 
converted to a hydrophilic sulfonic acid structure or carboxylic acid 
structure by heating. Though carboxylates turn to carboxylic acids even by 
simply heating, it is preferable to use the carboxylates together with a 
compound which generates an acid by heating (hereinafter, referred to as 
"heat acid generator") since the reaction is accelerated in the presence 
of an acid. In addition, if the sulfonates are combined with a heat acid 
generator the reaction, may, in some cases, be accelerated. 
The hydrophobic polymer compound is a polymer carrying in the side chain at 
least one of the groups represented by the above-described formulae (1) to 
(5). Sulfonic acid generating polymers having a group represented by the 
formulae (1) to (3) are preferable in that discrimination of 
hydrophobicity to hydrophilicity before and after recording by irradiation 
with a light is excellent. 
##STR5## 
Polymers which can generate a sulfonic acid in the side chain represented 
by the above-described formulae (1) to (3) by heating are described in 
detail below. 
In the formulae (1) to (3), L represents an organic group composed of a 
polyvalent non-metal atom necessary for connecting a substituent to a 
polymer main chain. The substituent herein referred to is a sulfonate 
group. R.sup.1 represents a substituted or unsubstituted alkyl group, a 
substituted or unsubstituted aryl group, or a cyclic imide group, R.sup.2 
and R.sup.3 represent a substituted or unsubstituted alkyl group or a 
substituted or unsubstituted aryl group, R.sup.4 represents a substituted 
or unsubstituted alkyl group, a substituted or unsubstituted aryl group, 
or --SO.sub.2 --R.sup.5. R.sup.5 represents a substituted or unsubstituted 
alkyl group or a substituted or unsubstituted aryl group. 
Preferable examples of R.sup.1 to R.sup.5 will be specifically described 
below. As the preferable example of the unsubstituted alkyl group R.sup.1, 
straight chain, branched chain and cyclic alkyl groups having 1 to 20 
carbon atoms are listed, and specific examples thereof include a methyl 
group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, 
heptyl group, octyl group, nonyl group, decyl group, undecyl group, 
dodecyl group, tridecyl group, hexadecyl group, octadecyl group, eicosyl 
group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, 
isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 
2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl 
group, and 2-norbornyl group. Among these, straight-chain alkyl groups 
having 1 to 12 carbon atoms, branched-chain alkyl groups having 3 to 12 
carbon atoms, and cyclic alkyl groups having 5 to 10 carbon atoms are 
preferable. 
When R.sup.1 represents a substituted alkyl group, as the substituent of 
the substituted alkyl group, monovalent non-metal atom groups other than 
hydrogen are used, and preferable examples thereof include halogen atoms 
(--F, --Br, --Cl, --I), a hydroxyl group, alkoxy group, aryloxy group, 
mercapto group, alkylthio group, arylthio group, alkyldithio group, 
aryldithio group, amino group, N-alkylamino group, N,N-dialkylamino group, 
N-arylamino group, N,N-diarylamino group, N-alkyl-N-arylamino group, 
acylamino group, carbamoyloxy group, N-alkylcarbamoyloxy group, 
N-arylcarbamoyloxy group, N,N-dialkylcarbamoyloxy group, 
N,N-diarylcarbamoyloxyl group, N-alkyl-N-arylcarbamoyloxy group, 
alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, 
N-alkylacylamino group, N-arylacylamino group, ureido group, 
N'-alkylureido group, N',N'-dialkylureido group, N'-arylureido group, 
N',N'-diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido 
group, N-arylureido group, N-alkyl-N-alkylureido group, 
N-alkyl-N-arylureido group, N',N'-dialkyl-N-alkylureido group, 
N',N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, 
N'-aryl-N-arylureido group, N',N'-diaryl-N-alkylureido group, 
N',N'-diaryl-N-arylureido group, N-alkyl-N'-aryl-N-alkylureido group, 
N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, 
aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, 
N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, 
N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl 
group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, 
N-alkylcarbamoyl group, N,N-dialkylcarbamoyl group, N-arylcarbamoyl group, 
N,N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, alkylsulfinyl 
group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo 
(--SO.sub.3 H) and conjugated basic groups thereof (hereinafter, 
abbreviated as a sulfonato group), alkoxysulfonyl group, aryloxysulfonyl 
group, sulfinamoyl group, N-alkyl sulfinamoyl group, N,N-dialkyl 
sulfinamoyl group, N-arylsulfinamoyl group, N,N-diarylsulfinamoyl group, 
N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, 
N,N-dialkylsulfamoyl group, N-arylsulfamoyl group, N,N-diarylsulfamoyl 
group, N-alkyl-N-arylsulfamoyl group, phosphono group (--PO.sub.3 H.sub.2) 
and conjugated basic groups thereof (hereinafter, abbreviated as a 
phosphonato group), dialkylphosphono group (--PO.sub.3 (alkyl).sub.2), 
diarylphosphono group (--PO.sub.3 (aryl).sub.2), alkylarylphosphono group 
(--PO.sub.3 (alkyl) (aryl)), monoalkylphosphono group (--PO.sub.3 (alkyl)) 
monoarylphosphono group (--PO.sub.3 (aryl)) and conjugated basic groups 
thereof (hereinafter, abbreviated as an arylphosphonato group), 
phosphonooxy group (--PO.sub.3 H.sub.2) and conjugated basic groups 
thereof (hereinafter, abbreviated as a phosphonatooxy group), 
dialkylphosphonooxy group (--OPO.sub.3 (alkyl).sub.2), diarylphosphonooxy 
group (--OPO.sub.3 (aryl).sub.2), alkylarylphosphonooxy group (--OPO.sub.3 
(alkyl) (aryl)), monoalkylphosphonooxy group (--OPO.sub.3 H(alkyl)) and 
conjugated basic groups thereof (hereinafter, abbreviated as an 
alkylphosphonatooxy group), monoarylphosphonooxy group (--OPO.sub.3 
H(aryl)) and conjugated basic group thereof (hereinafter, abbreviated as 
an arylphosphonatooxy group), cyano group, nitro group, aryl group, 
alkenyl group, and alkynyl group. 
In the substituent of the substituted alkyl group, specific examples of the 
alkyl group include the alkyl groups as described above, and specific 
examples of the aryl group include a phenyl group, biphenyl group, 
naphthyl group, tolyl group, xylyl group, mesityl group, cumenyl group, 
chlorophenyl group, bromophenyl group, chloromethylphenyl group, 
hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, 
phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, 
methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, 
dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, 
methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, 
phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group, 
cyanophenyl group, sulfophenyl group, sulfonatophenyl group, 
phosphonophenyl group, phosphonatophenyl group, and the like. Examples of 
an alkenyl group include a vinyl group, 1-propenyl group, 1-butenyl group, 
cinnamyl group, 2-chloro-1-ethenyl group, and the like. Examples of the 
alkenyl group include an ethynyl group, 1-propenyl group, 1-butynyl group, 
trimethylsilylethynyl group, and the like. As G.sup.1 in the acyl group 
(G.sup.1 CO--), hydrogen, and the above-described alkyl groups and aryl 
groups are listed. Among these substituents, more preferable examples 
include halogen atoms (--F, --Br, --Cl, --I), an alkoxy group, aryloxy 
group, alkylthio group, arylthio group, N-alkylamino group, 
N,N-dialkylamino group, acyloxy group, N-alkylcarbamoyloxy group, 
N-arylcarbamoyloxy group, acylamino group, formyl group, acyl group, 
carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl 
group, N-akylcarbamoyl group, N,N-dialkylcarbamoyl group, N-arylcarbamoyl 
group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonato group, 
sulfamoyl group, N-alkylsulfamoyl group, N,N-dialkylsulfamoyl group, 
N-arylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group, 
phosphonato group, dialkylphosphono group, diarylphosphono group, 
monoalkylphosphono group, alkylphosphonato group, monoarylphosphono group, 
arylphosphonato group, phosphonooxy group, phosphonatooxy group, aryl 
group, and alkenyl group. 
When R.sup.1 is a substituted alkyl group, as the alkylene group in the 
substituted alkyl group, there are listed divalent organic residual groups 
obtained by removing any one hydrogen atom from the above-described alkyl 
groups having 1 to 20 carbon atoms, and straight-chain alkylene groups 
having 1 to 12 carbon atoms, branched-chain alkylene groups having 3 to 12 
carbon atoms and cyclic alkylene groups having 5 to 10 carbon atoms are 
preferable. Preferable specific examples of the substituted alkyl groups 
obtained by combining the above-described substituents with alkylene 
groups include a chloromethyl group, bromomethyl group, 2-chloroethyl 
group, trifluoromethyl group, methoxymethyl group, methoxyethoxyethyl 
group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, 
tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, 
morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, 
N-cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, 
acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl 
group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, 
allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, 
carbamoylmethyl group, N-methylcarbamoylethyl group, 
N,N-dipropylcarbamoylmethyl group, N-(methoxyphenyl)carbamoylethyl group, 
N-methyl-N-(sulfophenyl)carbamoylmethyl group, sulfobutyl group, 
sulfonatobutyl group, sulfamoylpropyl group, N-tolylsulfamoylpropyl group, 
N-methyl-N-(phosphonophenyl)sulfamoyloctyl group, phosphonobutyl group, 
phosphonatohexyl group, diethylphosphonobutyl group, 
diphenylphosphonopropyl group, methylphosphonobutyl group, 
methylphosphonatobutyl group, tolylphosphonohexyl group, 
tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonatooxybutyl 
group, benzyl group, phenetyl gtoup, .alpha.-methylbenzyl group, 
1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl 
group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 
2-methylpropenylmethyl group, 2-propenyl group, 2-butynyl group, 3-butynyl 
group, and the like. 
When R.sup.1 is a unsubstituted aryl group, as preferable examples of the 
unsubstituted aryl group, condensed ring groups formed with 1 to 3 benzene 
rings, and condensed ring groups formed from a benzene ring and a 
5-membered unsaturated ring, are listed, and specific examples thereof 
include a phenyl group, naphthyl group, anthryl group, phenanthryl group, 
indenyl group, acenaphthenyl group and fluorenyl group. Among these, a 
phenyl group and naphthyl group are more preferable. The aryl group 
includes, in addition to the above-described carbon cyclic aryl groups, 
heterocyclic aryl groups. As the heterocyclic aryl group, there are used 
those having 3 to 20 carbon atoms and 1 to 5 hetero atoms such as a 
pyridyl group, furyl group, and quinolyl group obtained by 
ring-condensation of a benzene group, benzofuryl group, thioxanthone 
group, carbazol groups and the like. 
When R.sup.1 is a substituted aryl group, as examples of the substituted 
aryl group, the above-described type aryl groups carrying a monovalent 
non-metal atom group except hydrogen may be used as the substituent on 
ring-forming carbon atoms. As examples of preferable substituents, the 
above-described substituted or unsubstituted alkyl groups, and those 
previously exemplified as substituents on the substituted alkyl groups, 
are listed. Preferable specific examples of the substituted aryl group 
include a biphenyl group, tolyl group, xylyl group, mesityl group, cumenyl 
group, chlorophenyl group, bromophenyl group, fluorophenyl group, 
chloromethylphenyl group, trifluoromethylphenyl group, hydroxyphenyl 
group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl 
group, phenoxyphenyl group, methylthiophenyl group, tolylthiophenyl group, 
ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, 
acetyloxyphenyl group, benzoyloxyphenyl group, 
N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group, 
acetylaminophenyl group, N-methylbenzoylaminophenyl group, carboxyphenyl 
group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, 
chlorophenoxycarbonylphenyl group, carbamoylphenyl group, 
N-methylcarbamoylphenyl group, N,N-dipropylcarbamoylphenyl group, 
N-(methoxyphenyl)carbamoylphenyl group, 
N-methyl-N-(sulfophenyl)carbamoylphenyl group, sulfophenyl group, 
sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoylphenyl 
group, N,N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, 
N-methyl-N-(phosphonophenyl)sulfamoylphenyl group, phosphonophenyl group, 
phophonatophenyl group, diethylphosphonophenyl group, 
diphenylphosphonophenyl group, methylphosphonophenyl group, 
methylphosphonatophenyl group, tolylphosphonophenyl group, 
tolylphosphonatophenyl group, allyl group, 1-propenylmethyl group, 
2-butenyl group, 2-methylallylphenyl group, 2-methylpropenylphenyl group, 
2-propenylphenyl group, 2-butynylphenyl group, 3-butynylphenyl group and 
the like. 
When R.sup.1 is a cyclic imide group, as preferable examples of the cyclic 
imide group, those having 4 to 20 carbon atoms such as succinic imide, 
phthalic imide, cyclohexanedicarboxylic imide, norbornenedicarboxylic 
imide and the like are listed. 
Among other, it is particularly preferable from the view points of 
storability and heat decomposability when R.sup.1 is a primary or 
secondary alkyl which may have a substituent. 
When R.sup.2 and R.sup.3 represent a substituted or unsubstituted alkyl 
group, or substituted or unsubstituted aryl group, preferable examples 
thereof are the same as the preferable examples of the substituted or 
unsubstituted alkyl group, or substituted or unsubstituted aryl group of 
R.sup.1. 
When R.sup.4 represents a substituted or unsubstituted alkyl group, or 
substituted or unsubstituted aryl group, preferable examples thereof are 
the same as the preferable examples of the substituted or unsubstituted 
alkyl group, or substituted or unsubstituted aryl group of R.sup.1. When 
R.sup.4 is --SO.sub.2 --R.sup.5, R.sup.5 represents a substituted or 
unsubstituted alkyl group, or substituted or unsubstituted aryl group. 
When R.sup.5 represents a substituted or unsubstituted alkyl group, or 
substituted or unsubstituted aryl group, preferable examples thereof are 
the same as the preferable examples of the substituted or unsubstituted 
alkyl group, or substituted or unsubstituted aryl group of R.sup.1. 
L connects a polymer main chain with a sulfonate group which is a 
substituent thereof, in a sulfonic acid generating polymer. The organic 
group composed of a polyvalent non-metal atom represented by L is an 
organic group composed of 1 to 60 carbon atoms, 0 to 10 nitrogen atoms, 0 
to 50 oxygen atoms, 1 to 100 hydrogen atoms and 0 to 20 sulfur atoms. As 
more specific organic groups, those constituted of combinations of the 
following structural units are listed. 
##STR6## 
When L has a substituent, as the substituent, there can be used alkyl 
groups having 1 to 20 carbon atoms such as a methyl group, ethyl group and 
the like, aryl groups having 6 to 16 carbon atoms such as a phenyl group, 
naphthyl group, and the like, acyloxy groups having 1 to 6 carbon atoms 
such as a hydroxyl group, carboxyl group, sulfonamide group, 
N-sulfonylamide group and acetoxy group, alkoxy groups having 1 to 6 
carbon atoms such as a methoxy group and ethoxy group, halogen atoms such 
as chlorine and bromine, alkoxycarbonyl groups having 2 to 7 carbon atoms 
such as a methoxycarbonyl group, ethoxycarbonyl group and 
cyclohexyloxycarbonyl group, a cyano group, carbonates such as t-butyl 
carbonate, and the like. 
The sulfonic acid generating polymers in the present invention can be 
produced by conventionally known various polymerization methods such as 
radical polymerization, ion polymerization, polycondensation and the like. 
For example, the sulfonic acid generating polymers are obtained by radical 
polymerization using the radical polymerizable monomers shown below. 
##STR7## 
For obtaining the sulfonic acid generating polymer, only one of the 
monomers having the partial structures represented by the formulae (1) to 
(3) described above may be homo-polymerized or two or more of the monomers 
may be copolymerized. Further, there may be used a copolymer obtained by 
copolymerizing a monomer having a partial structure represented by the 
formulae (1) to (3) with another monomer. As examples of such a copolymer, 
there are listed those obtained by radical-copolymerization of exemplified 
radical-polymerizable monomers with other radical-polymerizable monomers. 
Examples of the other monomers used include known monomers such as 
acrylates, methacrylates, acrylamides, methacrylamides, vinyl esters, 
styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, 
maleic imide and the like. By copolymerizing such monomers, various 
physical properties such as film formability, film strength, 
hydrophilicity, hydrophobicity, solubility, reactivity, stability and the 
like can be improved. 
Specific examples of the acrylates include methyl acrylate, ethyl acrylate, 
(n- or i-)propyl acrylate, (n-, i-, sec- or t-)butyl acylate, amyl 
acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, chloroethyl acrylate, 
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 5-hydroxypentyl 
acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane 
monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl 
acrylate, chlorobenzyl acrylate, hydroxybenzyl acrylate, hydroxyphenethyl 
acrylate, dihydroxyphenethyl acrylate, furfuryl acrylate, 
tetrahydrofurfuryl acrylate, phenyl acrylate, hydroxyphenyl acrylate, 
chlorophenyl acrylate, sulfamoylphenyl acrylate, 
2-(hydroxyphenylcarbonyloxy)ethyl acrylate, and the like. 
Specific examples of the methacrylates include methyl methacrylate, ethyl 
methacrylate, (n- or i-)propyl methacrylate, (n-, i-, sec- or t-)butyl 
methacylate, amyl methacrylate, 2-ethylhexyl methacrylate, dodecyl 
methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 
2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, cyclohexyl 
methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, 
pentaerythritol monomethacrylate, glycidyl methacrylate, benzyl 
methacrylate, methoxybenzyl methacrylate, chlorobenzyl methacrylate, 
-hydroxybenzyl methacrylate, hydroxyphenethyl methacrylate, 
dihydroxyphenethyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl 
methacrylate, phenyl methacrylate, hydroxyphenyl methacrylate, 
chlorophenyl methacrylate, sulfamoylphenyl methacrylate, 
2-(hydroxyphenylcarbonyloxy)ethyl methacrylate, and the like. 
Specific examples of the acrylamides include acrylamide, 
N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, 
N-butylacrylamide, N-benzylacrylamide, N-hydroxyethylacrylamide, 
N-phenylacrylamide, N-tolylacrylamide, N-(hydroxyphenyl)acrylamide, 
N-(sulfamoylphenyl)acrylamide, N-(phenylsulfonyl)acrylamide, 
N-(tolylsulfonyl)acrylamide, N,N-dimethylacrylamide, 
N-methyl-N-phenylacrylamide, N-hydroxyethyl-N-methylacrylamide, and the 
like. 
Specific examples of the methacrylamides include methacrylamide, 
N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, 
N-butylmethacrylamide, N-benzylmethacrylamide, 
N-hydroxyethylmethacrylamide, N-phenylmethacrylamide, 
N-tolylmethacrylamide, N-(hydroxyphenyl)methacrylamide, 
N-(sulfamoylphenyl)methacrylamide, N-(phenylsulfonyl)methacrylamide, 
N-(tolylsulfonyl)methacrylamide, N,N-dimethylmethacrylamide, 
N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide, 
and the like. 
Specific examples of the vinyl esters include vinyl acetate, vinyl 
butyrate, vinyl benzoate, and the like. 
Specific examples of the styrenes include styrene, methylstyrene, 
dimethylstyrene, trimethylstyrene, ethylstyrene, propylstyrene, 
cyclohexylstyrene, chloromethylstyrene, trifluoromethylstyrene, 
ethoxymethylstyrene, acetoxymethylstyrene, methoxystyrene, 
dimethoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, 
iodostyrene, fluorostyrene, carboxystyrene, and the like. 
As the other monomers, there may be used where necessary monomers having 
cross-liking reactivity such as glycidyl methacrylate, 
N-methylolmethacrylamide, .omega.-(trimethoxysilyl)propyl methacrylate, 
2-isocyanate ethyl acrylate and the like. 
Among these other monomers, particularly suitably used are acrylates, 
methacrylates, acrylamides, methacrylamides, vinyl esters, styrenes 
acrylic acid, methacrylic acid, and acrylonitrile having not more than 20 
carbon atoms. 
The proportion of these other monomers used for synthesizing a copolymer is 
required to be an amount sufficient for improving the various physical 
properties, however, when the proportion is too high, the function of the 
partial structure of the general formula (1) is insufficient. Therefore, 
the total proportion of preferable other monomers is preferably 80% by 
weight or less, and more preferably 50% by weight or less. 
Specific examples of the sulfonic acid generating polymer in the present 
invention will be described below. 
##STR8## 
The numbers in the formulae represent molar composition of the polymer 
compound. 
Examples of solvents used in synthesizing the sulfonic acid generating 
polymer used in the present invention include tetrahydrofuran, ethylene 
dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, 
ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl 
ether, 2-methoxyethyl acetate, diethylene glycol dimethyl ether, 
1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, N,N-dimethylformamide, 
N,N-dimethylacetamide, toluene, ethyl acetate, methyl lactate, ethyl 
lactate, dimethylsulfoxide, water, and the like. These solvents are used 
alone or in combination of two or more. 
As the polymerization initiator used in synthesizing the sulfonic acid 
generating polymer used in the present invention by radical 
polymerization, known compounds such as azo-based initiators, peroxide 
initiators and the like can be used. 
The sulfonic acid generating polymer used in the present invention can be 
easily synthesized by methods known to those skilled in the art as 
described above. The polymerizable monomer is synthesized, for example, by 
de-hydrochlorination condensation of sulfonyl chloride with alcohol. 
Synthesis of the polymer can be carried out by the general procedure 
described above. A more specific synthesis method for the sulfonic acid 
generating polymer in the present invention is disclosed, for example, in 
Japanese Patent Application No. 9-026878. 
Next, the polymer which generates a carboxylic acid in the side chain by 
heating, which is another example of the components of the layer (b) used 
in the present invention, will be described in detail below. As such a 
carboxylate polymer, for example, those described in JP-B No. 2-27660, 
JP-A Nos. 5-181279, 6-83059, 6-282073, European Patent Application No. 
366590 and the like are listed. 
As specific examples of the preferable carboxylic acid generating polymer, 
polymers are listed having in the side chain a group represented by the 
following general formulae (4) and (5). 
##STR9## 
In the formulae (4) and (5), L represents an organic group composed of a 
polyvalent non-metal atom necessary for connecting a substituent to a 
polymer main chain. The substituent herein referred to is a carboxylate. 
R.sup.6 to R.sup.10 may be the same or different, and represent a hydrogen 
atom, or an alkyl group, alkenyl group, acyl group or alkoxycarbonyl group 
which may have a substituent, and R.sup.11 represents an alkyl group or 
alkenyl group which may have a substituent. Further, two of R.sup.6 to 
R.sup.8 or two of R.sup.9 to R.sup.11 may be connected to form a ring 
structure composed of 3 to 8 carbon atoms or hetero atoms. 
Preferable examples of the alkyl group in which R.sup.6 to R.sup.10 may 
have a substituent include those having 1 to 8 carbon atoms which may have 
a substituent, such as a methyl group, ethyl group, propyl group, n-butyl 
group, sec-butyl group, hexyl group, 2-ethylhexyl group, and octyl group. 
Preferable examples when the alkyl group is a cycloalkyl group include 
those having 3 to 8 carbon atoms which may have a substituent, such as a 
cyclopropyl group, cyclopentyl group and cyclohexyl group. Preferable 
examples of the alkenyl group which may have a substituent include those 
having 2 to 6 carbon atoms which may have a substituent, such as a vinyl 
group, propenyl group, allyl group, butenyl group, pentenyl group, hexenyl 
group and cyclohexenyl group. Preferable examples of the acyl group which 
may have a substituent include those having 1 to 10 carbon atoms which may 
have a substituent, such as a formyl group, acetyl group, propanoyl group, 
butanoyl group, octanoyl group and the like. Preferable examples of the 
alkoxycarbonyl group which may have a substituent include those having 2 
to 8 carbon atoms which may have a substituent, such as a methoxycarbonyl 
group, butoxycarbonyl group and the like. 
Preferable examples when R.sup.11 is an alkyl group and preferable examples 
when R.sup.11 is an alkenyl group are the same as those for R.sup.6 to 
R.sup.10. 
When R.sup.6 to R.sup.10 and R.sup.11 further have a substituent, 
preferable examples of the substituent include a hydroxyl group, halogen 
atoms (--F, --Cl, --Br, --I), a nitro group, cyano group, amide group, 
sulfonamide group, and further, alkoxy groups having 1 to 8 carbon atoms 
such as a methoxy group, ethoxy group, propoxy group, butoxy group and the 
like, and the alkyl groups, alkoxycarbonyl groups, acyl groups and 
cycloalkyl groups exemplified for R.sup.6 to R.sup.10. When any two of 
R.sup.6 to R.sup.10 and R.sup.11 on the same carbon atom are connected 
each other to form a ring, there are listed 3 to 8-membered rings which 
may have a hetero atom such as a cyclopropyl group, cyclopentyl group, 
cyclohexyl group, cycloheptyl group, tetrahydrofuranyl group, 
tetrahydropyranyl group and the like as the preferable ring. These may 
further have the above-described substituent. 
L connects a polymer main chain with a carboxylate in a carboxylic acid 
generating polymer. Other conditions thereof are the same as those for L 
in the general formulae (1) to (3). 
Among the polymers having a group represented by the general formulae (4) 
to (5), particularly preferable are polymers having at least one of the 
repeating units represented by the following formulae (7) to (12). 
##STR10## 
In the formulae (7) to (12), R.sup.12 and R.sup.13 may be the same or 
different and represent a hydrogen atom, cyano group, alkyl group or 
haloalkyl group, R.sup.14 represents a cyano group, --CO--OR.sup.15 or 
--CONR.sup.16 R.sup.17. R.sup.15 to R.sup.17 may be the same or different 
and represent a hydrogen atom, and an alkyl group, cycloalkyl group or 
alkenyl group which may have a substituent. R.sup.16 and R.sup.17 may be 
connected to each other to form a ring. X.sup.0 to X.sup.2 may be the same 
or different, and represent a single bond, or an alkylene group, 
alkenylene group or cycloalkenylene group which may have a substituent, 
--O--, --SO.sub.2 --, --O--CO--R.sup.18 --, --CO--O--R.sup.19 -- or 
--CO--NR.sup.20 --R.sup.21 --. R.sup.18, R.sup.19 and R.sup.21 may be the 
same or different, and represent a single bond, or a divalent alkylene 
group, alkenylene group or cycloalkylene group, and these groups may 
further form a divalent group together with an ether group, ester group, 
amide group, urethane group or ureide group. R.sup.20 may represent a 
hydrogen, or an alkyl group, cycloalkyl group or alkenyl group which may 
have a substituent. R.sup.6 to R.sup.11 have the same definitions as for 
the above-described general formulae (4) and (5). 
As the alkyl groups R.sup.12 and R.sup.13, there are listed those having 1 
to 4 carbon atoms which may have a substituent such as a methyl group, 
ethyl group, propyl group, n-butyl group and sec-butyl group. As the 
haloalkyl groups, there are preferably listed alkyl groups having 1 to 4 
carbon atoms and substituted by a fluorine atom, chlorine atom or bromine 
atom, for example, a fluoromethyl group, chloromethyl group, bromomethyl 
group, fluoroethyl group, chloroethyl group, bromoethyl group and the 
like. 
R.sup.14 represents a cyano group, --CO--OR.sup.15 or --CONR.sup.16 
R.sup.17. As the alkyl groups R.sup.15 to R.sup.17, there are listed those 
having 1 to 4 carbon atoms which may have a substituent, such as a methyl 
group, ethyl group, propyl group, n-butyl group and sec-butyl group. As 
the cycloalkyl group, there are preferably listed those having 3 to 8 
carbon atoms which may have a substituent, such as a cyclopropyl group, 
cyclopentyl group and cyclohexyl group. As the alkenyl group, there are 
listed those having 2 to 6 carbon atoms which may have a substituent, such 
as a vinyl group, propenyl group, allyl group, butenyl group, pentenyl 
group, hexenyl group and cyclohexenyl group. 
X.sup.0 to X.sup.2 may be the same or different, and represent a single 
bond, or an alkylene group, alkenylene group or cycloalkenylene group 
which may have a substituent, --O--, --SO.sub.2 --, --O--CO--R.sup.18 --, 
--CO--O--R.sup.19 or --CO--NR.sup.20 --R.sup.21 --. The alkylene groups 
X.sup.0 to X.sup.2 may preferably have a substituent. For example, those 
having 1 to 8 carbon atoms are listed, such as a methylene group, ethylene 
group, propylene group, butylene group, hexylene group, octylene group and 
the like. As the alkenylene group, there are preferably listed those 
having 2 to 6 carbon atoms which may have a substituent, such as an 
ethenylene group, propenylene group, butenylene group and the like. As the 
cycloalkylene group, there are preferably listed those having 5 to 8 
carbon atoms which may have a substituent, such as a cyclopentylene group, 
cyclohexylene group and the like. As the alkyl group R.sup.20, there are 
listed those having 1 to 4 carbon atoms which may have a substituent, such 
as a methyl, ethyl group, propyl group, n-butyl group and sec-butyl group. 
As the cycloalkyl group, there are listed those having 3 to 8 carbon atoms 
which may have a substituent, such as a cyclopropyl group, cyclopentyl 
group and cyclohexyl group. As the alkenyl group, there are preferably 
listed those having 2 to 6 carbon atoms which may have a substituent, such 
as a vinyl group, propenyl group, allyl group, butenyl group, pentenyl 
group, hexenyl group and cyclohexenyl group. The alkylene groups, alkenyl 
groups and cycloalkylene groups R.sup.18, R.sup.19 and R.sup.21 include 
those exemplified above, and further, divalent groups formed by connecting 
those groups with at least one of ether groups, ester groups, amide 
groups, urethane groups and ureide groups. 
When R.sup.12 to R.sup.21 and X.sup.0 to X.sup.2 have a substituent, the 
substituent preferably is an alkyl group having 1 to 4 carbon atoms such 
as a methyl group, ethyl group, propyl group and the like, hydroxyl group, 
nitro group, further, an alkoxy group having 1 to 8 carbon atoms such as a 
methoxy group, ethoxy group, propoxy group, butoxy group or the like. 
The carboxylic acid generating polymer can be produced by conventionally 
known various polymerization methods such as radical polymerization, ion 
polymerization, polycondensation and the like, in the same manner as the 
sulfonic acid generating polymer. Monomers having a group represented by 
the formulae (4) to (5) may be polymerized alone or two or more of them 
may be copolymerized. Further, monomers having a group represented by the 
formulae (4) to (5) may be copolymerized with the other monomer 
exemplified for the sulfonic acid generating polymer. 
Specific examples of repeating structural units represented by the general 
formulae (7) to (12) include, but are not limited to, the following units 
(a1) to (a30). 
##STR11## 
Among above-described carboxylate polymers, those of an alkoxymethyl ester 
type represented by the structural unit (5) are particularly suitable due 
to their extremely excellent heat sensitivity. 
The polymer having at least one of groups represented by the 
above-described formulae (1) to (5) used in the present invention has a 
weight average molecular weight of preferably 2.0.times.10.sup.3 or more, 
and more preferably in the range from 5.0.times.10.sup.3 to 
3.0.times.10.sup.5. The number-average molecular weight is preferably 
8.0.times.10.sup.2 or more, and further preferably in the range from 
1.0.times.10.sup.3 to 2.5.times.10.sup.5. The polydispersibility 
(weight-average molecular weight/number-average molecular weight) is 
preferably 1 or more, and more preferably in the range from 1.1 to 10. 
These polymer compounds may be in the form of a random polymer, block 
polymer, graft polymer and the like, and preferably random polymers. 
The sulfonic acid generating polymer or carboxylic acid generating polymer 
used in the present invention may be used alone or in combination. The 
sulfonic acid generating polymer or carboxylic acid generating polymer can 
be used in a proportion from 20 to 100% by weight, and preferably from 50 
to 100% by weight based on the total weight of solid components in the 
heat sensitive layer. If the amount added is less than 20% by weight, 
sufficient high sensitization may not sometimes be attained. 
The layer (b) in the present invention may contain other additives added 
optionally. For example, the addition of a heat acid generator is 
preferable in that heat sensitivity is enhanced since decomposition into a 
sulfonic acid or carboxylic acid is promoted. In the present invention, 
the heat source which makes layer (b) hydrophilic is layer (c) which can 
be removed by heat mode, however, depending on occasions, it is possible 
to add also to a heat sensitive layer a light absorbing agent to act as a 
supplement for converting irradiated light to heat, for example, an 
infrared ray absorbing agent may be added when the light source is 
infrared laser. However, if the amount added thereof is too large, 
efficient hydrophilization near the substrate which is the effect of the 
present invention is lost. When an absorbing agent is added, it is 
preferable that absorbance in relation to the exposure light source is 
about 0.5 or less. 
The heat acid generator added to the layer (b) is one which becomes, after 
being decomposed by heat, a strong acid which can promote the 
above-described conversion of a carboxylate to a carboxylic acid or 
conversion of a sulfonate to a sulfonic acid. An agent which generates by 
heat decomposition a strong acid manifesting a pKa in water preferably of 
4 or less, and more preferably of 2.5 or less is advantageous. For 
example, any of the groups of compounds usually used as a light acid 
generator can be used, and in addition, there can be used alkyl esters of 
organic oxy acids having a pKa of 4 or less, and preferably 3 or less, 
such as sulfonic acid, phosphoric acid, phosphorous acid, phosphonic acid, 
boric acid and the like. Use of a heat acid generator having a weight loss 
temperature (decomposition temperature) calculated by TG/DTA is from 80 to 
300.degree. C. is preferable from the viewpoint of storagability and heat 
decomposability, and more preferably, the weight loss temperature is from 
110 to 200.degree. C. 
Examples of the compound which generate an acid by heating include, but are 
not limited to, the following groups of compound. Diazonium salts 
described in S. I. Schlesinger, Photogr. Sci. Eng., 18, 387 (1974), T. S. 
Bal et al., Polymer, 21, 423 (1980) and the like, ammonium salts described 
in U.S. Pat. Nos. 4,069,055, 4,069,056, JP-A No. 3-140,140 and the like, 
phosphonium salts described in D. C. Necker et al., Macromolecules, 17, 
2468 (1984), C. S. wen et al. , Tech, Proc. Conf. Rad. Curing ASIA, p478, 
Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055, 4,069,056 and the like, 
iodonium salts described in J. V. Crivello et al. , Macromolecules, 10 
(6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent 
Application No. 104,143, U.S. Pat. No. 4,837,124, JP-A Nos. 2-150,848, 
2-296,514 and the like, sulfonium salts described in J. V. Crivello et 
al., Polymer J. 17, 73 (1985), J. V. Crivello et al., J. Org. Chem., 43, 
3055 (1978), W. R. Watt et al., J. Polymer Sci. , Polymer Chem. Ed., 22, 
1789 (1984), J. V. Crivello et al. , Polymer Bull., 14, 279 (1985), J. V. 
Crivello et al., Macromorecules, 14 (5), 1141 (1981), J. V. Crivello et 
al. , J. Polymer Sci., Polymer Chem. Ed., 17, 2877 (1979), European Patent 
Application No. 370, 693, U.S. Pat. No. 3,902,114, European Patent 
Application Nos. 233,567, 297,443, 297,442, 422,570, 279,210, U.S. Pat. 
Nos. 4,933,377, 4,760,013, 4,734,444, 2,833,827, DE Patent Nos. 2,904,626, 
3,604,580, 3,604,581 and the like, selenonium salts described in J. V. 
Crivello et al., Macromolecules, 10 (6), 1307 (1977), J. V. Crivello et 
al., J. Polymer Sci., Polymer Chem. Ed., 17, 1047 (1979) and the like, 
onium salts such as an arsonium salt and the like described in C. S. Wen 
et al., Tech, Proc. Conf. Rad. Curing ASIA, p478, Tokyo, Oct (1988) and 
the like, organic halogen compounds described in U.S. Pat. No. 3,905,815, 
JP-B No. 46-4,605, JP-A Nos. 48-36,281, 55-32,070, 60-239,736, 61-169,835, 
61-169,837, 62-58,241, 62-212,401, 63-70,243, 63-298,339 and the like, 
organometal/organic halogen compounds described in K. Meier et al. , J. 
Rad. Curing, 13 (4), 26 (1986), T. P. Gill et al., Inorg. Chem., 19, 3007 
(1980), D. Astruc, Acc. Chem. Res., 19 (12), 377 (1896), JP-A No. 
2-161,445 and the like, photo acid-generating agents having an 
0-nitrobenzyl type protecting group described in S. Hayase et al., J. 
Polymer Sci., 25,753 (1987), E. Reichmanis et al., J. Polymer Sci., 
Polymer Chem. Ed., 23, 1 (1985), Q. Q. Zhu et al., J. Photochem., 36, 85, 
39, 317 (1987), B. Amit et al. , Tetrahedron Lett. , (24) 2205 (1973), D. 
H. R. Barton et al. , J. Chem. Soc., 3571 (1965), P. M. Collins et al., J. 
Chem. Soc., Perkin I, 1965 (1975), M. Rudinstein et al., Tetrahedron 
Lett., (17), 1445 (1975), J. W. Walker et al. , J. Am. Chem. Soc., 110, 
7170 (1988), S. C. Busman et al., J. Imaging Technol., 11 (4), 191 (1985), 
H. M. Houlihan et al., Macromolecules, 21, 2001 (1988), P. M. Collins et 
al., J. Chem. Soc., Chem. Commun., 532 (1972), S. Hayase et al., 
Macromolecules, 18, 1799 (1985), E. Reichmanis et al., J. Electrochem. 
Soc., Solid State Sci. Technol., 130 (6), F. M. Houlihan et al., 
Macromolecules, 21, 2001 (1988), European Patent Application Nos. 
0,290,750, 046,083, 156,535, 271,851, 0,388,343, U.S. Pat. Nos. 3,901,710, 
4,181,531, JP-A Nos. 60-198,538, 53-133,022 and the like, compounds which 
are photo-decomposed to generate sulfonic acid represented by 
iminosulfonate and the like described in M. TUNOOKA et al., Polymer 
Preprints Japan, 35 (8), G. Berner et al. , J. Rad. Curing, 13 (4), W. J. 
Mijs et al ., Coating Technol., 55 (697), 45 (1983), Akzo, H. Adachi et 
al., Polymer Preprints, Japan, 37 (3), European Patent Application Nos. 
0,199,672, 84,515, 199,672, 044,115, 0,101,122, U.S. Pat. Nos. 4,618,564, 
4,371,605, 4,431,774, JP-A Nos. 64-18,143, 2-245,756, 4-365,048 and the 
like, disulfone compounds described in JP-A No. 61-166,544, 
o-naphthoquinone diazide-4-sulfonic halides described in JP-A No. 
50-36,209 (U.S. Pat. No. 3,969,118), o-naphthoquinone diazide compounds 
described in JP-A No. 55-62,444 (U.K. Patent No. 2,038,801) and JP-B No. 
1-11,935. 
In addition to these additives, sulfonates which generate an acid by heat 
described in Japanese Patent Application Nos. 9-26878, 9-89451, and 
9-85328 can be used. 
When infrared ray absorbing agents are added to layer (b) the infrared ray 
absorbing agents are a dye or pigment effectively absorbing an infrared 
ray having a wavelength of 760 nm to 1,200 nm. It is preferable that the 
dye or pigment has an absorption maximum between the wavelengths of 760 nm 
and 1,200 nm. 
As dyes, known dyes commercially available or those disclosed in the 
literature (such as "Senryo Binran (Dye Handbook)" edited by Yuki Gosei 
Kagaku Kyokai (Organic Synthetic Chemistry Association), published in 
1970), can be used. Specifically, examples may include azo dyes, metal 
complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine 
dyes, carbonium dyes, quinoneimine dyes, methyne dyes, cyanine dyes, and 
metal thiolate complexes. 
Examples of preferable dyes may include cyanine dyes disclosed in JP-A Nos. 
58-125,246, 59-84,356, 59-202,829, and 60-78,787; methyne dyes disclosed 
in JP-A Nos. 58-173,696, 58-181,690, and 58-194,595; naphthoquinone dyes 
disclosed in JP-A Nos. 58-112,793, 58-224,793, 59-48,187, 59-73,996, 
60-52,940, and 60-63,744; squarylium dyes disclosed in JP-A No. 
58-112,792; and cyanine dyes disclosed in U.K. Patent No. 434,875. 
Furthermore, near infrared absorption sensitizing agents disclosed in U.S. 
Pat. No. 5,156,938 can be preferably used. Moreover, substituted aryl 
benzo(thio)pyrylium salts disclosed in U.S. Pat. No. 3,881,924; trimethyne 
thiapyrylium salts disclosed in JP-A No. 57-142,645 (U.S. Pat. No. 
4,327,169); pyrylium-containing compounds disclosed in JP-A Nos. 
58-181,051, 58-220,143, 59-41,363, 59-84,248, 59-84,249, 59-146,063, and 
59-146,061; cyanine dyes disclosed in JP-A No. 59-216,146; pentamethyne 
thiopyrylium salts disclosed in U.S. Pat. No. 4,283,475; and pyrylium 
compounds disclosed in JP-B Nos. 5-13,514 and 5-19,702 can be preferably 
used as well. 
As other examples of preferable dyes, near infrared absorption dyes 
disclosed in U.S. Pat. No. 4,756,993 represented by formulas (I) and (II) 
can be presented. 
Among these dyes, particularly preferable are cyanine dyes, squarylium 
dyes, pyrylium salts, and nickel thiolate complexes. 
Pigments usable in the present invention may include commercially available 
pigments and those disclosed in the Color Index (C. I.) Manual, "Saishin 
Ganryo Binran (Modern Pigment Manual)" edited by Nippon Ganryo Gijutsu 
Kyokai (Japan Pigment Technology Association), published in 1977; "Saishin 
Ganryo Oyo Gijutsu (Modern Pigment Application Technology)" by CMC Press, 
published in 1986; and "Insatsu Ink Gijutsu (Printing Ink Technology)" by 
CMC Press, published in 1984. 
Examples of pigments may include black pigments, yellow pigments, orange 
pigments, brown pigments, red pigments, purple pigments, blue pigments, 
green pigments, fluorescent pigments, metal powder pigments, and polymer 
bond pigments. Specifically, insoluble azo pigments, azo lake pigments, 
condensation azo pigments, chelate azo pigment, phthalocyanine pigments, 
anthraquinone pigments, perylene and perynone pigments, thioindigo 
pigments, quinacridone pigments, dioxazine pigments, isoindolinone 
pigments, quinophthalone pigments, colored lake pigments, azine pigments, 
nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, 
inorganic pigments, and carbon black can be used. Among these examples, 
carbon black is preferable. 
These pigments can be used without surface treatment, or can be used after 
the application of a surface treatment. Examples of surface treatment 
methods may include a method of surface coating with a resin or a wax, a 
method of adhering a surfactant thereto, and a method of bonding a 
reactive substance (such as a silane coupling agent, an epoxy compound, or 
a polyisocyanate) with the pigment surface. The above-mentioned surface 
treatment methods are disclosed in "Kinzokusekken no Seishitsu to Oyo 
(Natures and Applications of Metal Soaps)" by Sachi Press; "Insatsu Ink 
Gijutsu (Printing Ink Technology)" by CMC Press; published in 1984; and 
"Saishin Ganryo Oyo Gijutsu (Modern Pigment Application Technology)" by 
CMC Press, published in 1986. 
A pigment particle size of 0.01 .mu.m to 10 .mu.m is preferable, 0.05 .mu.m 
to 1 .mu.m is more preferable, and 0.1 .mu.m to 1 .mu.m is the most 
preferable. A pigment particle size smaller than 0.01 .mu.m is not 
preferable in terms of the stability of the pigment dispersion in a 
photosensitive layer coating solution. On the other hand, a pigment 
particle size larger than 10 .mu.m is not preferable in terms of the 
uniformity of the image recording layer. 
As methods of dispersing a pigment, known dispersing methods employed in 
ink production or toner production can be used. Examples of the dispersing 
machine include ultrasonic dispersing machines, sand mills, attritors, 
pearl mills, super mills, ball mills, impellers, dispersers, KD mills, 
colloid mills, dynatrons, triple roll mills, and pressure kneaders. 
Details thereof are described in "Saishin Ganryo Oyo Gijutsu (Modern 
Pigment Application Technology)" by CMC Press, published in 1986. 
These dyes or pigments can be added to an image recording material in an 
amount of 0.01 to 50% by weight based on the weight of the total solid 
component of the image recording material, preferably in an amount of 0.1 
to 10% by weight, and more preferably in an amount of 0.5 to 10% by weight 
in the case of a dye, and more preferably in an amount of 3.1 to 10% by 
weight in the case of a pigment. An amount of a pigment or dye less than 
0,01% by weight causes low sensitivity. On the other hand, an amount more 
than 50% by weight produces stains in nonimage portions at the time of 
printing. 
In the present invention, other additives may further be added to layer (b) 
according to necessity. For example, a dye having a large absorption in 
the visible light region can be added as a coloring agent. Specifically, 
examples may include Oil Yellow #101, Oil Yellow #103, Oil Pink #312, Oil 
Green BG, Oil Blue BOS, Oil Blue #603, Oil Black BY, Oil Black BS, Oil 
Black T-505 (manufactured by Orient Chemical Industry, Co., Ltd.), 
Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), 
Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), 
Methylene Blue (CI52015), and dyes disclosed in JP-A No.62-293,247. 
In order to guarantee stable treatment regardless of fluctuations in the 
printing conditions, a nonionic surfactant disclosed in JP-A Nos. 
62-251,740 and 3-208,514 and an ampholytic surfactant disclosed in JP-A 
Nos. 59-121,044 and 4-13,149 can be added to layer (b) of the present 
invention. 
Examples of nonionic surfactants may include sorbitan tristearate, sorbitan 
monopalmitate, sorbitan triolate, mono glyceride stearate, and 
polyoxyethylene nonylphenyl ether. 
Examples of ampholytic surfactants may include alkyl di(aminoethyl)glycine, 
alkyl polyaminoethylglycine hydrochloride, 
2-alkyl-N-carboxyethyl-N-hydroxyethyl imidazolinium betaine, and 
N-tetradecyl-N,N-substituted betaine (for example, Amorgen K manufactured 
by Dai-Ichi Kogyo Co., Ltd.). 
The amount of the above-described nonionic surfactants and ampholytic 
surfactants is preferably from 0.05 to 15% by weight, and more preferably 
from 0.1 to 5% by weight in an image recording material. 
In order to provide flexibility to the film, etc., a plasticizer can be 
added as needed to layer (b) of the present invention. Examples of a 
plasticizer may include polyethylene glycol, tributyl citrate, diethyl 
phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, 
tricresyl phosphate, tributyl phosphate, trioctyl phosphate, 
tetrahydrofurfuryl oleate, an oligomer and a polymer of acrylic acid or 
methacrylic acid. 
In addition to these examples, epoxy compounds, vinyl ethers, phenol 
compounds having an alkoxy methyl group and phenol compounds having a 
hydroxymethyl group disclosed in Japanese Patent Application No. 7-18,120, 
can also be added. Other polymer compounds can be added in order to 
increase the strength of the film. 
The planographic printing plate of the present invention can be produced, 
in general, by dissolving the above-described component in a solvent and 
applying the resultant solution to an appropriate support. Solvents used 
herein may include, but are not limited to, ethylene dichloride, 
cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene 
glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxy ethyl acetate, 
1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl 
lactate, N,N-dimethyl acetamide, N,N-dimethyl formamide, tetramethyl urea, 
N-methyl pyrrolidone, dimethyl sulfoxide, sulfolane, 
.gamma.-butyrolactone, toluene and water. 
These solvents are used alone or in combinations thereof. The concentration 
of the above-described components (total solid component including 
additives) is preferably from 1 to 50% by weight in the solution. 
A surfactant for improving the applicability, such as a fluorine-containing 
surfactant disclosed in JP-A No. 62-170,950 can be added to layer (b) of 
the present invention. The amount added is preferably from 0.01 to 1% by 
weight based on the total solid component of the image recording material, 
and more preferably from 0.05 to 0.5% by weight. 
The amount coated of layer (b) obtained after coating and drying (solid 
component) differs depending on use, and in the case of the printing plate 
precursor (1), 0.5 to 5.0 g/m.sup.2 is preferable and 0.5 to 1.5 g/m.sup.2 
is more preferable. In the present invention since layer (b) is coated 
after the formation of layer (a) and both of them are partially 
compatibilized at the interface, adhesion between hydrophilic layer (a) 
and hydrophobic layer (b) becomes excellent and releasing between the 
layers is effectively prevented. 
The amount coated of layer (b) (solid component) in the printing plate 
precursors (2) and (3) differs depending on the overall structure of the 
printing plate precursor, and in general, is preferably 2.0 g/m.sup.2 or 
less, and more preferably 1.0 g/m.sup.2 or less. For conducting coating, 
various methods can be used, and for example, bar coater coating, rotation 
coating, spray coating, curtain coating, dip coating, air knife coating, 
blade coating, roll coating, and the like are listed. 
Layer (c) 
In the present invention, the phrase "removal by heat mode exposure" 
neither means that all recording layer components disappear in the stage 
of irradiation in the irradiation range nor means that substantial 
reduction in weight necessarily accompanies the irradiation stage. The 
phenomenon caused by the irradiation is characterized in that form change 
in the form of the recording layer solid follows, and it means that the 
structure of the layer is substantially decomposed. Scientifically, 
phenomena such as ablation, evaporation, melting and the like are 
included, and these are not necessarily accompanied by a reduction in 
weight. However, such a form change in the present invention is required 
to cause at least partial removal of irradiation portions in the 
intermediate layer, in some cases in the irradiation stage, and in other 
cases in post treatment or printing process. Such form change can be 
recognized by various microscopic means, and the recording layer in the 
present invention is required to be able to cause at least such a form 
change. 
Any hydrophilic solid thin layer or organic thin layer which can absorb 
irradiated light can be suitably used in layer (c) in the planographic 
printing plate precursor of the present invention, and any known materials 
in this field, and the fields of metal processing, laser processing and 
the like can be used. The preferable layer (c) is generally one whose 
absorbance is as high as possible and whose thickness is as thin as 
possible, in view of the printing ability and image forming speed 
(sensitivity). When absorbance of irradiated light is low, the sensitivity 
decreases since the amount of heat generation due to light-to-heat 
conversion is low. When the film thickness is high, the sensitivity 
decreases because of the large amount of heat required for the removal or 
the removal becomes completely impossible, thereby causing blemishes in 
printing. The preferable absorbance is 0.1 or more, more preferably 0.5 or 
more, and most preferably 1.0 or more. The preferable thickness largely 
depends on the components of the layer (c) and when the layer (c) is an 
inorganic solid thin film (metal film and the like) described below, it is 
preferably 5000 .ANG. or less, and more preferably 1000 .ANG. or less, and 
in the case of an organic thin film, it is preferable that the amount 
coated is 500 mg/m.sup.2 or less, and more preferably 100 mg/m.sup.2 or 
less. The lower limit of the film thickness depends on absorbance, and the 
preferable thickness may advantageously be determined so that absorbance 
is 0.1 or more. 
As the solid thin film, various inorganic solid thin films can be used 
described for example in JP-A Nos. 55-113307 and 52-37104. Specifically, 
for example, Mg, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, 
Ni, Ru, Rh, Pd, Ir, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Si, Ge, Pb, Sn, 
As, Sb, Bi, Se, Te, and the like are listed, and among these, Mg, Ti, Cr, 
Cu, Ag, Zn, Al, In, Sn, Bi, and Te are particularly advantageous in view 
of their sensitivity. In addition, there can be also used thin alloy films 
composed of compounds obtained by optionally changing the oxidation 
condition of the above-described metals (oxygen compounds, nitrogen 
compounds, and the like), stainless steel, brass and the like, chalcogen 
materials (S, Se simple substances, and the like), binary chalcogen 
materials (As--S system, As--Se system, As--Te system, S--Se system, 
Sb--Se system, Sb--Te system, Bi--S system, Bi--Se system, Bi--Te system, 
Ge--S system, Sn--S system, and the like), ternary chalcogen materials 
(As--S--Te system, As--Se--Te system, Ge--Sn--S system, and the like), 
graphite and the like, and further, inorganic thin films prepared by 
modifying these materials by oxidation, doping, and the like according to 
necessity can also be used. These thin films can be formed by usual 
methods such as dry methods such as vapor deposition (resistance heating, 
electron beam and the like), sputtering and ion plating on a substrate, 
and wet coating methods such as a method using electrochemical depositing, 
a sol gel method and the like, and in addition, the thin film can be 
formed for example, by a silver halide emulsion layer diffusion transfer 
developing method, however, the effect of the present invention is not 
limited by these film forming methods. 
When an organic thin film is used as layer (c), the organic thin layer 
contains a suitable light absorbing agent. The organic thin film is 
usually constituted of a binder resin having film forming ability and a 
light absorbing agent, and optionally, a compound obtained by chemically 
binding these two components may also be used. 
As the binder resin used in the organic thin film, those widely and 
generally known can be used without particular restriction. Specifically, 
novolak reins (phenol-formaldehyde resin, cresol-formaldehyde resin and 
the like), urea-formaldehyde resins, melamine-formaldehyde resins, alkyd 
resins, (meth)acrylic resins (polymethyl methacrylate, polyethyl acrylate 
and the like), styrene-based resins (polystyrene, 
.alpha.-methylpolystyrene and the like), polyamide-based resins (nylons), 
polyester resins, polyurethane-based resins, polyurea-based resins, 
polycarbonate resins, silicone-based resins, esters of polyvinylacetal 
(polyvinyl acetate and the like), acetals of polyvinyl alcohol 
(polyvinylburyral and the like), vinyl-based resin (polyvinyl chloride and 
the like), polyalkenes (polyethylene and the like) styrene-butadiene 
resins, polyvinylidene chlorides, fluorine-based resins, 
polyorganosiloxanes (polydimethylsiloxane and the like), organism polymer 
modified materials (polysaccharide, oligosaccharide, polypeptide and the 
like) and modified materials thereof (cellulose acetate, cellulose acetate 
butyrate and the like). 
As the light absorbing agent used in the organic thin film, compounds which 
can absorb light energy radiation used for recording can be used without 
limitation. In the production of a printing plate using infrared laser 
which is a preferable embodiment of the present invention, it is desirable 
that the above-described light absorbing agent is an infrared absorbing 
agent. As examples of preferable infrared ray absorbing agents, those 
previously exemplified for the additive to layer (b) may be listed. 
For producing the layer (c) when layer (c) is an organic thin film, the 
same methods used for the above-described layer (b) are listed. In 
general, layer (c) can be produced by dissolving components in a solvent 
and coating the mixture on a suitable substrate. Examples of the solvent 
herein used include, but are not limited to, ethylene dichloride, 
cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene 
glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 
1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl 
lactate, N,N-dimethylacetamide, N,N-dimethylformamide, tetramethylurea, 
N-methylpyrrolidone, dimethylsulfoxide, sulfolane, Y-butyrolactone, 
toluene, water and the like. 
These solvents are used alone or in combination. The concentration of the 
above-described components (total solid components in layer (c) including 
additives) in the solvent is preferably from 1 to 50% by weight. The 
amount coated (solid components) on a substrate obtained after coating and 
drying is not particularly restricted, and in general, is preferably from 
0.2 to 3.0 g/m.sup.2. For conducting coating, various methods can be used, 
and for example, bar coater coating, rotation coating, spray coating, 
curtain coating, dip coating, air knife coating, blade coating, roll 
coating and the like are listed. 
To the intermediate layer in the present invention, a surfactant for 
improving coatability, for example, fluorine-based surfactants as 
described in JP-A No. 62-170950 can be added. The amount added thereof is 
preferably from 0.01 to 1% by weight, and more preferably from 0.05 to 
0.5% by weight based on the total weight of the solid components in the 
image recording material. 
It is known that among the above-described general structures which cause 
form change by heat mode exposure and become substantially removable, use 
of specific materials and structure is advantageous from the viewpoint of 
recording sensitivity. Such known technology can be utilized also in the 
present invention without exception. For example, use or addition of a 
self-oxidizing resin such as nitrocellulose and the like described in JP-A 
No. 49-117102 (U.S. Pat. No. A86656) and U.S. Pat. No. 3,962,513 is 
suitable in that recording sensitivity is enhanced. Acrylic cross-linked 
polymers described in U.S. Pat. No. 3,574,657 have high sensitivity and 
are thus suitable. Further, the sensitivity is relatively improved also by 
the use of heat-decomposable resins of polyesters, polymethyl 
methacrylates, and polyoxymethylenes described in U.S. Pat. No. 4,054,094. 
WO90-01635 and 94-01280 describe a group of polymers excellent in 
heat-decomposability, and any of these are suitable from the viewpoint of 
sensitivity. The sensitivity can be improved by the addition of halogen, 
Ge, Si and the like to a chalcogen-based recording layer, or by the 
addition, as a constituting component, of an alkaline metal such as Na, K 
and the like, an alkaline earth metal such as Ca, Sr, and the like, a IVb 
group element such as Si, Ge, Sn, Pb, and the like, a IIIb group element 
such as Tl, Al, In, and the like, a IIb group element such as Zn and the 
like, a lanthanum-based rare earth element such as Eu, Sm, and the like, 
an actinide rare earth element such as U and the like, as well as other 
elements, as described in JP-A No. 50-11307. As described in JP-A No. 
52-37140, used of an aluminum substrate having an anodized coating of 0.5 
.mu.m or more is advantageous from the viewpoint of heat scattering. 
Addition of compounds (CrS, Cr.sub.2 S, Cr.sub.2 S.sub.3, MoS.sub.2, MnS, 
FeS, FeS.sub.2, CoS, Co.sub.2 S.sub.3, NiS, Ni.sub.2 S, PbS, Cu.sub.2 S, 
Ag.sub.2 S, ZnS, In.sub.2 S.sub.3, GeSx (wherein, x represents a positive 
integer), SnS, SnS.sub.2, PbS, As.sub.2 S.sub.3, Sb.sub.2 S.sub.3, 
Bi.sub.2 S.sub.2, MgF.sub.2, CaF.sub.2, RhF.sub.3, MoO, InO, In.sub.2 O, 
In.sub.2 O.sub.3, GeO, PbO) to a metal recording layer which is deformed 
by heating, or making the metal recording layer into a multi-layer 
structure as described in JP-A No. 53-33702 is effective for high 
sensitization. When a light absorbing agent is combined with a 
halogen-containing polymer as disclosed in JP-A No. 62-9993, sensitivity 
preferably increases. Further, a recording layer mainly composed of a 
light absorbing agent, thermoplastic resin and a lower molecular weight 
compound soluble in an organic solvent as disclosed in JP-A No. 5-138848 
is advantageous from the viewpoints of recording sensitivity and 
blemishability of a print. When cyanoacrylate polymers 
(poly(methyl-2-cyanoacrylate), 
poly(methyl-2-cyanoacrylate-co-ethyl-2-cyanoacrylate), 
poly(methoxyethyl-2-cyanoacrylate), and the like) are used as a binder as 
described in U.S. Pat. No. 5,605,780, a planographic plate precursor 
excellent in printability having relatively high sensitivity is obtained 
since the binder is excellent in heat decompability. 
An additive for improving the various properties thereof as a printing 
plate precursor may be added to layer (c). As preferable examples of the 
additive, the above-described heat acid generators, coloring agents, 
surfactants, plasticizers and the like exemplified for layer (b) are 
listed. 
The substrate will now be described. 
The substrate used in the planographic printing plate precursor of the 
present invention has at least a surface which is hydrophilic. As such a 
substrate, conventionally known hydrophilic substrates used for 
planographic printing plates can be used without limitation. The substrate 
used is preferably a dimensionally stable plate material, and examples 
thereof include paper, paper laminated with a plastic (for example, 
polyethylene, polypropylene, polystyrene or the like) metal plates (for 
example, aluminum, zinc, copper and the like) plastic films (for example, 
cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose 
butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene 
terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, 
polyvinylacetal and the like), paper and plastic films laminated or 
deposited with the above-described metals, and the like, and suitable 
known physical or chemical treatments may be optionally performed on the 
surface of these substrates for the purpose of imparting hydrophilicity, 
increasing strength and the like. 
In particular, as preferable substrates, paper, polyester films or aluminum 
plates are listed, and among these, particularly preferable is an aluminum 
plate which has excellent dimensional stability, is relatively cheap, and 
can provide a surface excellent in hydrophilicity and strength through 
surface treatment according to demands. Further, a complex sheet prepared 
by bonding an aluminum sheet on a polyethylene terephthalate film is also 
preferable as described in JP-B No. 48-18327. As the aluminum plate, a 
pure aluminum sheet, and alloy plates mainly composed of aluminum and 
containing a small amount of hetero atoms are suitably used, and further, 
plastic films on which aluminum is laminated or deposited are permissible. 
Examples of the hetero atoms contained in the aluminum alloy include 
silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, 
nickel, titanium and the like. The content of hetero elements in the alloy 
is at most 10% by weight. In the present invention, particularly 
preferable aluminum is pure aluminum, however, it is difficult to produce 
completely pure aluminum due to refining technology, therefore, aluminum 
containing a slight amount of hetero elements may also be allowable. Thus, 
the composition of the aluminum plate used in the present invention is not 
specified, and an aluminum plate composed of conventionally known and used 
materials can be appropriately utilized. The thickness of the aluminum 
plate used in the present invention is from about 0.1 mm to 0.6 mm, 
preferably from 0.15 mm to 0.4 mm, and particularly preferably from 0.2 mm 
to 0.3 mm. 
In the case of a substrate having a metal surface, in particular an 
aluminum surface, it is preferable that a surface treatment such as a 
roughening (graining) treatment, immersion treatment in an aqueous 
solution of sodium silicate, potassium fluorinated zirconate, phosphate 
salt and the like, or an anodizing treatment is performed. 
The roughening treatment of the surface of an aluminum plate is conducted 
by various methods, for example, a mechanical roughening method, a method 
for electrochemically dissolving and roughening the surface, and a method 
for selectively dissolving the surface chemically. As mechanical methods, 
known methods can be used such as a ball grinding method, brush grinding 
method, blast grinding method, buffing grinding method and the like. As 
electrochemical roughening methods, there are methods using alternating 
current or direct current in an electrolyte solution such as hydrochloric 
acid, nitric acid and the like. Also, a method combining both means can be 
used as disclosed in JP-A No. 54-63902. Prior to the roughening of an 
aluminum plate, if desired, there maybe conducted, for example, a 
degreasing treatment using a surfactant, organic solvent or alkaline 
aqueous solution for removing rolling oil on the surface. 
Further, there is preferably used an aluminum plate which is, after 
roughening treatment, subjected to immersion treatment in an aqueous 
sodium silicate solution. As described in JP-B No. 47-5125, an aluminum 
plate is suitably used which is subjected to anodizing treatment, then, 
immersed into an aqueous solution of an alkaline metal silicate. The 
anodizing treatment is carried out by applying current using aluminum as 
an anode in an electrolyte solution composed solely of, for example, an 
aqueous solution or non-aqueous solution of an inorganic acid such as 
phosphoric acid, chromic acid, sulfuric acid, boric acid and the like, or 
an inorganic acid such as oxalic acid, sulfamic acid and the like, or 
salts thereof, or composed of a combination of two or more of these. 
Further, silicate electric deposition as described in U.S. Pat. No. 
3,658,662 is also effective. 
Further, surface treatment combining a substrate on which an electrolytic 
grain is applied, the above-described anodizing treatment and sodium 
silicate treatment is also useful as disclosed in JP-B No. 46-27481 and 
JP-A Nos. 52-58602 and 52-30503. 
As disclosed in JP-A No. 56-28893, a substrate which is subjected to 
mechanical roughening, chemical etching, electrolytic grain, anodizing 
treatment and sodium silicate treatment in sequence is also suitable. 
Further, a substrate on which a water-soluble resin, for example, a polymer 
and copolymer containing as the side chain a polyvinylphosphonate group or 
sulfonate group, polyacrylic acid, water-soluble metal salt (for example, 
zinc borate) or yellow dye, amine salt and the like is applied as a 
primer, after the above-described treatments, is also suitable. 
As disclosed in Japanese Patent Application No. 5-304358, there is also 
suitably used a sol-gel treated substrate on which a functional group 
which may cause addition reaction by radical is bonded by covalent 
linkage. 
As other preferable examples, there are also listed those prepared by 
providing a water resistant hydrophilic layer as the surface layer on any 
substrate. As such a surface layer, there are listed, for example, layers 
composed of an inorganic pigment and a bonding agent described in U.S. 
Pat. No. 305,295 and JP-A No. 56-13168, a hydrophilic swelling layer 
described in JP-A No. 9-80744, and a sol-gel film composed of titanium 
oxide, polyvinyl alcohol and silicic acids described in Japanese Patent 
Application National Publication (Laid-Open) No. 8-507727. 
The planographic printing plate precursor of the present invention is 
produced in the manner described above. In particular, a method is 
preferable in which an image is exposed by a solid laser or semiconductor 
laser which emits an infrared ray having a wavelength of 700 nm to 1200 nm 
to produce a plate. In the present invention, the printing plate may be 
installed in a printing machine immediately after image exposure and 
printing may be conducted, however, if necessary, it is also possible that 
the printing plate precursor is previously installed in a printing machine 
and image exposure is conducted on the printing machine and printing is 
conducted in such a condition. Production of a printing plate in this way 
is preferable since the production process can be simplified. However, 
between the image exposure process and the printing process, there may be 
conducted post treatment processes such as washing of the surface of a 
recording layer and post heating, if necessary. By these processes, it 
becomes possible to further improve the resistance to blemishing of 
non-image portions, strengthen image portions, improve printing durability 
and scratch resistance, and decrease the exposure time necessary for image 
exposure, or maintain desirable surface properties of a planographic 
printing plate after image exposure for a longer period of time. 
The planographic printing plate precursor (1) having undergone image 
exposure can be developed with water after the exposure, subjected to gum 
coating if necessary, then, installed in a printing machine for conducting 
printing, and further, can also be installed in a printing machine 
immediately after exposure (without a developing process) to conduct 
printing. Namely, in the plate production method using the planographic 
printing plate precursor of the present invention, a planographic printing 
plate can be produced without a particular developing treatment. The water 
development in the present invention indicates development using a 
developing solution having a pH of 2 or more composed of water or mainly 
composed of water. 
The planographic printing plate obtained by such treatment is applied to an 
offset printing machine, and used for printing for providing a large 
number of prints.

EXAMPLES 
The following examples further illustrate the present invention in detail 
below, but do not limit the scope thereof. 
Preparation of Substrate 
An aluminum plate (material 1050) having a thickness of 0.30 mm was 
degreased by washing with trichloroethylene. A roughening treatment was 
applied to the aluminum plate by graining the surface with a nylon brush 
and a suspension in which a 400 mesh powder of pumice stone was suspended 
in water. The plate was then washed with water. The plate was etched by 
being immersed in a 25% aqueous solution of sodium hydroxide at 45.degree. 
C. for 9 seconds and washed with water. The plate was further immersed in 
a 2% HNO.sub.3 for 20 seconds and washed with water. The etching amount of 
the grained surface was about 3 g/m.sup.2. Then, the plate was provided 
with a direct current anodic oxidization film of about 3 g/m.sup.2 with 7% 
H.sub.2 SO.sub.4 as the electrolyte and a current density of 15 
A/dm.sup.2, washed with water, and dried. The resulting substrate was 
named S-1. The contact angle against a water drop in air of S-1 was 100 or 
less. 
Example of planographic printing plate (1) 
Synthesis of hydrophilic polymer compound 
0.5 g of benzoyl peroxide was added as a polymerization initiator to 60 g 
of vinyl acetate and 40 g of methyl acrylate, and the resulting mixture 
was dispersed in 300 ml of water containing 3 g of a partially saponified 
polyvinyl alcohol and 10 g of NaCl as dispersing stabilizers. 
The dispersion was stirred for 6 hours at 65.degree. C. to conduct 
suspension polymerization. The content of the methyl acrylate component in 
the resulting copolymer was identified by NMR spectrum at 48 mol % . The 
intrinsic viscosity in a benzene solution at 30.degree. C. was 2.10. 
Then 8.6 g of this copolymer was added to a saponification reaction 
solution composed of 200 g of methanol, 10 g of water and 40 ml of 5N NaOH 
and the mixture was stirred in suspension, saponification reaction was 
conducted at 25.degree. C. for 1 hour, then, the temperature was increased 
to 65.degree. C. and further saponification reaction was conducted for 5 
hours. 
The resulting saponification reaction product was washed fully with 
methanol, and freeze-dried. The degree of saponification was 98.3 mol %, 
and it was verified as a result of infrared spectrum measurement that 
strong absorption derived from --COO-- group was 1570 cm.sup.-1. 
Synthesis of heat sensitive polymer compound 
Synthesis of monomer (4) 
200 ml of acetonitrile, 11 g of cyclohexyl alcohol and 8.8 g of pyridine 
were charged into a 500 ml three-necked flask, and stirred. To this was 
added 20.2 g of vinylbenzenesulfonyl chloride dropwise while being cooled 
with ice. After completion of the addition, the mixture was stirred for 2 
hours, then, poured into 1 liter of water and extracted with ethyl 
acetate. The product was dried over magnesium sulfate, then the solvent 
was distilled under reduced pressure, and the residue was purified by 
column chromatography on silica gel to obtain a monomer (4). Element 
Analysis: the calculated values were; C: 63.13%, H: 6.81%, the actual 
values were; C: 63.01%, H: 6.85% 
Synthesis of monomer (5) 
A monomer (5) was synthesized in the same manner as for the monomer (4) 
except that 2,2,2-trifluoroethyl alcohol was used instead of cyclohexyl 
alcohol. 
Synthesis of monomer (10) 
A monomer (10) was synthesized in the same manner as for the monomer (4) 
except that the alcohol described below was used instead of cyclohexyl 
alcohol. 
##STR12## 
Synthesis of monomer (49) 
1.06 g of 2,4-dinitrotoluene, then 500 g of methacrylic acid and 488 g of 
dihydropyran were charged into a 500 ml three-necked flask. To this 
mixture was added concentrated hydrochloric acid while being cooled with 
ice. After completion of the addition, the reaction mixture was warmed to 
about 60.degree. C. and stirring was continued for 2 hours and 30 minutes 
at the same temperature. The reaction mixture was cooled to room 
temperature, and the reaction mixture was changed to alkaline with an 
aqueous sodium hydroxide solution. From this mixture, product was 
extracted with ethyl acetate, and the organic layer was dried over 
magnesium sulfate then concentrated under reduced pressure. The resulting 
solution was verified by identification by NMR that: monomer (49): 88.1% 
by weight, ethyl acetate: 12.9% by weight. 
Synthesis of heat sensitive polymer compound (1) 
20 g of the monomer (4) and 40 g of methyl ethyl ketone were charged into a 
200 ml three-necked flask, and to this was added 0.25 g of 
azobisdimethylvaleronitrile at 65.degree. C. under nitrogen flow. This 
temperature was maintained for 5 hours while being stirred, then the 
solvent was distilled off under reduced pressure, to obtain a solid 
material. By GPC, it was verified as a polymer having a weight-average 
molecular weight of 15200. 
Synthesis of heat sensitive polymer compounds (2) to (4) 
Heat sensitive polymer compounds (2) to (4) were synthesized in the same 
manner as for the heat sensitive polymer compound (1) except the raw 
material monomer (4) was changed for the monomers shown in the following 
Table 1. The average molecular weights of the resulting polymers are shown 
in the following Table 1. 
TABLE 1 
______________________________________ 
Weight-average 
Monomer used molecular weight 
______________________________________ 
Heat sensitive polymer 
Monomer (5) 20 g 16000 
compound (2) 
Heat sensitive polymer Monomer (10) 20 g 18000 
compound (3) 
Heat sensitive polymer Monomer (49) 20 g 20000 
compound (4) 
______________________________________ 
Synthesis of heat sensitive polymer compound (5) 
7.18 g of the monomer (4), 0.31 g of ethyl acrylate and 15 g of methyl 
ethyl ketone were charged into a 100 ml three-necked flask, and to this 
was added 0.1 g of azobisdimethylvaleronitrile at 65.degree. C. under 
nitrogen flow. The mixture was stirred for 5 hours at the same 
temperature, then, the methyl ethyl ketone was distilled off under reduced 
pressure, to obtain a solid material. By GPC (polystyrene standard), it 
was recognized as a polymer having a weight-average molecular weight of 
18000. 
Synthesis of heat sensitive polymer compounds (6) to (8) 
Heat sensitive polymer compounds (6) to (8) were synthesized in the same 
manner as for the heat sensitive polymer compound (5) except the raw 
material monomer (4) was replaced by the monomers shown in the following 
Table 2. The average molecular weights of the resulting polymers are shown 
in the following Table 2. 
TABLE 2 
______________________________________ 
Weight-average 
Monomer used molecular weight 
______________________________________ 
Heat sensitive polymer 
Monomer (5) 7.18 g 16000 
compound (6) 
Heat sensitive polymer Monomer (10) 9.05 g 18000 
compound (7) 
Heat sensitive polymer Monomer (49) 4.59 g 25000 
compound (8) 
______________________________________ 
Examples 1 to 9 
The following solution [A] was coated on the above-described substrate S-1, 
and dried for 2 minutes at 100.degree. C. to obtain an aluminum plate 
coated with a layer (a). The weight after drying was 1.1 g/m.sup.2. 
______________________________________ 
Solution [A] 
______________________________________ 
Hydrophilic polymer compound 
1.0 g 
Fluorine-based surfactant 0.06 g 
(trade name: Megafack F-177, manufactured by 
Dainippon Ink & Chemicals, Inc.) 
Methyl alcohol 5.0 g 
Purified water 5.0 g 
(Only to [B-9],) dye 1 0.08 g 
______________________________________ 
Nine solutions [B-1] to [B-9] were prepared by changing the type of heat 
sensitive polymer compound in the following solution [B] as is shown in 
Table 3. The resulting solutions were respectively coated on the 
above-described aluminum plate coated with layer (a), and dried at 
80.degree. C. for 3 minutes to obtain planographic printing plate 
precursors [B-1] to [B-9]. The weight after drying was 1.2 g/m.sup.2. 
______________________________________ 
Solution [B] 
______________________________________ 
Heat sensitive polymer compound (Table 3) 
4.0 g 
Infrared ray absorbing agent 0.15 g 
(IR-125, manufactured by Wako Pure Chemical 
Industries Ltd.) 
Acid generator: Salt of 0.15 g 
diphenyliodoniumanthraquinonesulfonic acid 
Dye in which counter ion in Victoria Pure 0.05 g 
Blue BOH is changed to 1-naphthalenesulfonic acid 
Fluorine-based surfactant 0.06 g 
(Megafack F-177, manufactured by Dainippon Ink 
& Chemicals, Inc.) 
Methyl ethyl ketone 20 g 
.gamma.- Butyrolactone 10 g 
1-Mehoxy-2-propanol 8 g 
Water 2 g 
______________________________________ 
TABLE 3 
______________________________________ 
Planographic printing 
Heat sensitive polymer 
plate precursor compound 
______________________________________ 
Example 1 [B-1] (1) 
Example 2 [B-2] (2) 
Example 3 [B-3] (3) 
Example 4 [B-4] (4) 
Example 5 [B-5] (5) 
Example 6 [B-6] (6) 
Example 7 [B-7] (7) 
Example 8 [B-8] (8) 
Example 9 [B-9] (1) 
______________________________________ 
The resulting planographic printing plate precursors [B-1] to [B-9] were 
exposed by YAG laser emitting an infrared ray having a wavelength of 1064 
nm at laser power: 360 mW and scanning speed: 3.0 m/s. After the exposure, 
they were heated at 110.degree. C. for 1 minute, then printed using a 
Hydel KOR-D Machine. In this procedure, it was observed whether blemishes 
occured on non- image portions of the print or not. The results are shown 
in Table 4. 
TABLE 4 
______________________________________ 
Blemishes on non- 
Planographic printing image portions in 
plate precursor printing 
______________________________________ 
Example 1 [B-1] None 
Example 2 [B-2] None 
Example 3 [B-3] None 
Example 4 [B-4] None 
Example 5 [B-5] None 
Example 6 [B-6] None 
Example 7 [B-7] None 
Example 8 [B-8] None 
Example 9 [B-9] None 
______________________________________ 
As is apparent from the results of Table 4, according to the planographic 
printing plate of the present invention, excellent prints having no 
blemishes on non-image portions were obtained even at the low energy 
exposure of a 3.0 m/s scanning speed. 
Comparative Examples 1 to 8 
Eight solutions [C-1] to [C-8] were prepared by changing the type of heat 
sensitive polymer compound in the following solution [C]. The resulting 
solutions were respectively coated on the above-described aluminum plate 
S-1 treated as described above, and dried at 100.degree. C. for 2 minutes 
to obtain planographic printing plate precursors [C-1] to [C-8]. The 
weight after drying was 1.2 g/m.sup.2. 
______________________________________ 
Solution [C] 
______________________________________ 
Heat sensitive polymer compound (Table 5) 
4.0 g 
Infrared ray absorbing agent 0.15 g 
(IR-125, manufactured by Wako Pure Chemical 
Industries Ltd.) 
Acid genertor: Salt of 0.15 g 
diphenyliodoniumanthraquinonesulfonic acid 
Dye in which counter ion in Victoria Pure 0.05 g 
Blue BOH is changed to 1-naphthalenesulfonic acid 
Fluorine-based surfactant 0.06 g 
(Megafack F-177, manufactured by Dainippon Ink 
& Chemicals, Inc.) 
Methyl ethyl ketone 20 g 
.gamma.-Butyrolactone 10 g 
1-Methoxy-2-propanol 8 g 
Water 2 g 
______________________________________ 
TABLE 5 
______________________________________ 
Planographic printing 
Heat sensitive polymer 
plate precursor compound 
______________________________________ 
Comparative example 1 
[C-1] (1) 
Comparative example 2 [C-2] (2) 
Comparative example 3 [C-3] (3) 
Comparative example 4 [C-4] (4) 
Comparative example 5 [C-5] (5) 
Comparative example 6 [C-6] (6) 
Comparative example 7 [C-7] (7) 
Comparative example 8 [C-8] (8) 
______________________________________ 
One of the two planographic printing plate precursors obtained for each of 
[C-1] to [C-8] was exposed by YAG laser emitting an infrared ray having a 
wavelength of 1064 nm at laser power: 360 mW and scanning speed: 2.0 m/s 
and the other of each of the plates was exposed by the YAG laser at laser 
power: 360 mW and scanning speed: 3.0 m/s. After the exposure, both plates 
were heated at 110.degree. C. for 1 minute, then printed using a Hydel 
KOR-D Machine. In this procedure, it was observed whether blemishes 
occured on non-image portions of the print or not. The results are shown 
in Table 6. 
TABLE 6 
______________________________________ 
Blemished on non-image 
Planographic portions in printing 
printing plate Scanning Speed: 
Scanning Speed: 
precursor 2.0 m/s 3.0 m/s 
______________________________________ 
Comparative 
[C-1] None slightly 
example 1 
Comparative [C-2] None slightly 
example 2 
Comparative [C-3] None 
example 3 
Comparative [C-4] None slightly 
example 4 
Comparative [C-5] None 
example 5 
Comparative [C-6] None 
example 6 
Comparative [C-7] None 
example 7 
Comparative [C-8] None slightly 
example 8 
______________________________________ 
As apparent from the results of Table 6, it was found that in the 
planographic printing plates of the comparative examples obtained by 
forming only a recording layer corresponding to layer (b) in the present 
invention, when exposed at a scanning speed of 2.0 m/s, there was no 
problem, however, when exposed at a scanning speed of 3.0 m/s, all of the 
resulting prints had blemishes on non-image portions, and there were 
problems with developability when exposed at low energy. 
Examples of planographic printing plate (2) 
S-2 
A coating solution having the composition described below was prepared 
using a sulfonic acid generating polymer (1p-7, GPC weight-average 
molecular weight: 20000, heat decomposition temperature by TGA: 
155.degree. C.). The resulting solution was coated on the hydrophilic 
treated surface of S-1 by a spin coater so that the amount coated after 
drying at 100.degree. C. for 2 minutes was 0.3 g/m.sup.2. The substrate 
having the intermediate layer (layer (b)) thus provided was called S-2. 
The surface had a contact angle against a water drop in air of 80.degree.. 
______________________________________ 
(Intermediate layer coating solution) 
______________________________________ 
Sulfonic acid generating polymer 
5 g 
Methyl ethyl ketone 80 g 
Dimethylacetamide 20 g 
______________________________________ 
S-3 
A substrate S-3 was obtained in the same manner as for S-2 except that a 
sulfonic acid generating polymer (1p-2, GPC weight-average molecular 
weight: 10000, heat decomposition temperature by TGA: 120.degree. C.) was 
used and the amount coated was 0.2 g/m.sup.2. The surface had a contact 
angle against a water drop in air of 100.degree.. 
S-4 
A substrate S-4 was obtained in the same manner as for S-2 except that a 
sulfonic acid generating polymer (1p-8, GPC weight-average molecular 
weight: 50000, heat decomposition temperature by TGA: 134.degree. C.) was 
used and the amount coated was 0.5 g/m.sup.2. The surface had a contact 
angle against a water drop in air of 90.degree.. 
S-5 
A substrate S-5 was obtained in the same manner as for S-2 except that a 
sulfonic acid generating polymer (1p-26, GPC weight-average molecular 
weight: 30000, heat decomposition temperature by TGA: 160.degree. C.) was 
used and the amount coated was 1.0 g/m.sup.2. The surface had a contact 
angle against a water drop in air of 80.degree.. 
S-6 
A substrate S-6 was obtained in the same manner as for S-2 except that a 
sulfonic acid generating polymer (1p-25, GPC weight-average molecular 
weight: 30000, heat decomposition temperature by TGA: 155.degree. C.) was 
used and the amount coated was 0.2 g/m.sup.2. The surface had a contact 
angle against a water drop in air of 80.degree.. 
S-7 
A substrate S-7 was obtained in the same manner as for S-2 except that a 
sulfonic acid generating polymer (1p-21, GPC weight-average molecular 
weight: 30000, heat decomposition temperature by TGA: 145.degree. C.) was 
used and the amount coated was 0.2 g/m.sup.2. The surface had a contact 
angle against a water drop in air of 75.degree.. 
S-8 
A substrate S-8 was obtained in the same manner as for S-2 except that a 
carboxylic acid generating polymer (homopolymer having structure a-15, GPC 
weight-average molecular weight: 100,000) was used instead of the sulfonic 
acid generating polymer and the amount coated was 0.2 g/m.sup.2. 
S-9 
A substrate S-9 was obtained by heating the substrate S-3 in an oven at 
150.degree. C. for 1 minute. Infrared absorption spectra of the surfaces 
of S-3 and S-9 were measured by the FT-IR diffusion reflection method. 
Absorptions at 1359 cm.sup.-1 and 1099 cm derived from sulfonates observed 
in s-3 disappeared in S-9, and instead, absorptions at 1041 cm.sup.-1 and 
1012 cm.sup.-1 derived from sulfonates were observed. Namely, it was found 
that the sulfonic acid generating ability of the sulfonic acid generating 
polymer contained in the intermediate layer coated on the substrate S-9 
was lost. The surface of the substrate S-9 had a contact angle against a 
water drop in air of 10.degree. or less. 
Examples 10 to 14, Comparative Examples 9, 10 
Copper metal was deposited by vacuum deposition on the surfaces of the 
substrates S-2, S-3, S-4, S-7, S-8 and the hydrophilic substrate S-1 
having the intermediate layer of the present invention obtained as 
described above, and the substrate S-9 having the intermediate layer 
containing no functional group represented by the general formulae (1) to 
(5) so as to form copper films having a thickness of 100 .ANG., to obtain 
the planographic printing plate precursors of Examples 10 to 14, and 
Comparative Examples 9 and 10, respectively. These were exposed image-wise 
by a YAG laser having an oscillation wavelength of 1064 nm, an output of 1 
W, and a beam diameter of 20 mm, and offset printing was conducted using a 
Hydel KOR-D Machine. The resistance to blemishing of the resulting prints 
were evaluated visually according to the following standard. 
Evaluation of blemish resistance 
No blemishing over a wide range of water/ink balance 
.smallcircle.: Slight blemishing depending on water/ink balance 
The results of the printing and the evaluation of blemish resistance are 
shown in the following Table 7. 
Examples 15 to 19, Comparative Examples 11, 12 
The printing plate precursors obtained in the above-described Examples 10 
to 14, Comparative Examples 9 and 10 were stored for 3 days under 
conditions of a temperature of 60.degree. C. and a humidity of 45% RH, 
then were exposed image-wise under the same conditions as in Example 1 and 
printing was conducted. The results are shown in Table 7 below. 
TABLE 7 
______________________________________ 
Polymer used in 
intermediate layer Printing evaluation result 
______________________________________ 
Example 10 
1 p-7 *.sup.1 
10000 or more excellent prints 
were obtained. Blemishing resistance: .circleincircle. 
Example 11 1 p-2 *.sup.1 10000 or more excellent prints 
were obtained. Blemishing resistance: .circleincircle. 
Example 12 1 p-8 *.sup.1 10000 or more excellent prints 
were obtained. Blemishing resistance: .circleincircle. 
Example 13 1 p-21 *.sup.1 10000 or more excellent prints 
were obtained. Blemishing resistance: .circleincircle. 
Example 14 a-15 *.sup.2 10000 or more excellent prints 
were obtained. Blemishing resistance: .smallcircle. 
Comparative No intermediate Whole surface was blemished 
example 9 layer significantly, and no image-wise 
print was obtained. 
Comparative Containing sul- Image portions became faint after 
example 10 fonate group fewer than 100 prints. 
Example 15 1 p-7 *.sup.1 10000 or more excellent prints 
were obtained. 
Example 16 1 p-2 *.sup.1 About 5000 excellent prints were 
obtained. 
Example 17 1 p-8 *.sup.1 10000 or more excellent prints 
were obtained. 
Example 18 1 p-21 *.sup.1 10000 or more excellent prints 
were obtained. 
Example 19 a-15 *.sup.2 About 4000 excellent prints were 
obtained. 
Comparative No intermediate Whole surface was blemished 
example 11 layer significantly, and no image-wise 
print was obtained. 
Comparative Sulfonate Image portions became faint after 
example 12 group *.sup.3 fewer than 100 prints. 
______________________________________ 
*.sup.1 : Sulfonic acid generated polymer 
*.sup.2 : Carboxylic acid generated polymer 
*.sup.3 : 1 p8 heated product, containing sulfonate group 
When the planographic printing plates of the examples having the layer (b) 
and the layer (c) of the present invention were applied directly to a 
printing machine after exposure and printing was conducted, a large number 
of excellent prints were obtained, as is apparent from Table 7. Further, 
it was found from comparison between Example 10 and Example 14 that the 
print using a sulfonic acid generating polymer is more excellent than the 
print using a carboxylic acid generating polymer. This tendency did not 
change after storage of the planographic printing plate precursors at a 
high temperature and a high humidity, and it was found that the 
planographic printing plate precursors of the present invention have 
excellent storability at a high temperature and a high humidity. 
Examples 20, 21, Comparative Examples 13 
A coating solution having the composition described below was coated at a 
coating weight of 1 g/cm.sup.2 as a recording layer (layer (c)) on the 
substrates S-5, S-6 and S-1 to obtain the planographic printing plate 
precursors of Examples 20 and 21 and Comparative Example 13, respectively. 
These plates were exposed using a YAG laser having an oscillation 
wavelength of 1064 nm, an output of 1 W and a beam diameter of 30 mm while 
the scanning speed was continuously changed. Printing was conducted using 
the resulting printing plates, and the line width at which it became 
impossible for ink to adhere by exposure was determined using a 
microscope, and exposing energy at the plate surface at which the line 
width was 30 mm was measured as a sensitivity value. The results are shown 
in Table 8 below. 
______________________________________ 
Coating solution for recording layer 
______________________________________ 
poly (.alpha.-methylstyrene) 
1.0 g 
Infrared ray absorbing agent 0.15 g 
(NK-3508, manufactured by Nippon Kanko Shikiso 
Kenkyusho K.K.) 
Dye in which counter ion in Victoria Pure 0.05 g 
Blue BOH is changed to 1-naphthalenesulfonic acid 
Fluorine-based surfactant 0.06 g 
(Megafack F-177, manufactured by Dainippon Ink 
& Chemicals, Inc.) 
Methyl ethyl ketone 20 g 
Methyl alcohol 7 g 
______________________________________ 
##STR13## 
TABLE 8 
______________________________________ 
Polymer used in 
intermediate layer Sensitivity 
______________________________________ 
Example 20 1 p-25 *.sup.1 
200 mJ/cm.sup.2 
Example 21 1 p-21 *.sup.1 200 mJ/cm.sup.2 
Comparative example 13 No intermediate 500 mJ/cm.sup.2 
layer 
______________________________________ 
*.sup.1 : Sulfonic acid generated polymer 
As is apparent from Table 8, the planographic printing plates of the 
present invention have excellent sensitivity, and can provide excellent 
writing even by exposure at low energy. 
Example 22 
A planographic printing plate precursor was made in the same manner as in 
Example 20 except that the infrared ray absorbing agent in the recording 
layer was substituted by IR-125 (manufactured by Wako Pure Chemical 
Industries Ltd.). This plate precursor was exposed image-wise using a 
semiconductor laser having an oscillation wavelength of 840 nm and an 
output of 500 mW, then printing was conducted to obtain 10000 or more 
excellent prints having no faintness in image portions and no 
contamination on non-image portions at all. 
Examples of planographic printing plate (3) 
A thin film of Ti was made by vacuum deposition so that the thickness 
thereof was 300 .ANG. as the layer (c), on the substrate S-1. The 
resulting sample was called M-1. Then, a coating solution having the 
composition described below was prepared. The resulting coating solution 
was coated on M-1 by a spin coater so that the amount coated after drying 
at 100.degree. C. for 2 minutes was 1.0 g/m.sup.2. Thus, a printing plate 
precursor P-1 was obtained as Example 23. The surface of P-1 had a contact 
angle against a water drop in air of 80.degree.. 
______________________________________ 
Sulfonic acid generating polymer 
15 g 
(1p-7, GPC weight-average molecular weight: 20,000, 
heat decomposition temperature by TGA: 155.degree. C.) 
Methyl ethyl ketone 80 g 
Dimethylacetamide 20 g 
______________________________________ 
The resulting P-1 was exposed image-wise with scanning using a 
semiconductor laser optical system having an oscillation wavelength of 840 
nm, a beam diameter of 30 .mu.m and an energy at the plate surface of 20 
mW under conditions where the energy concentration was 200 mJ/cm.sup.2. 
The obtained plate could be immediately subjected to offset printing using 
a Hydel KOR-D Machine to obtain 10000 or more excellent positive prints. 
Comparative Example 14 
Plate C-1 for comparison was obtained in the same manner as for the 
production of P-1 except that the layer (c) was not provided on the 
substrate S-1. The contact angle against a water drop in air of the 
surface of C-1 was 80.degree.. Then, C-1 was heated in an oven at 
150.degree. C. for 1 minute, and the infrared absorption spectrum was 
measured before and after the heating. As a result, absorptions at 1359 
cm.sup.-1 and 1099 cm.sup.-1 derived from sulfonates observed before the 
heating disappeared completely, and instead, absorptions at 1041 cm.sup.-1 
and 1012 cm.sup.-1 derived from sulfonates were recognized. The surface 
after the heating had a contact angle against a water drop in air of 
10.degree. or less. 
The substrate C-1 was used, and the whole surface was exposed with scanning 
using the same semiconductor laser optical system as in Example 23 under 
conditions where the energy concentration was 200 mJ/cm . The contact 
angle against a water drop in air of the surface after exposure was 
80.degree., and also regarding FT-IR, no change was recognized before and 
after the exposure. Further, scanning exposure was conducted image-wise 
using the same semiconductor laser optical system as in Example 1 under 
conditions where the energy concentration was 200 mJ/cm.sup.2, then 
immediately offset printing was conducted under the same conditions as for 
Example 23. As a result, ink adhered to the whole surface and no image was 
obtained at all. 
Comparative Example 15 
Further, M-1 on which the layer (b) was not provided in Example 23 was 
subjected to image-wise scanning exposure using the same semiconductor 
laser optical system as in Example 23 under conditions where the energy 
concentration was 200 mJ/cm.sup.2, then immediately offset printing was 
conducted under the same conditions as for Example 23. As a result, ink 
adhered to the whole surface and no image was obtained at all. When the 
exposure energy concentration was changed to 100 mJ/cm.sup.2 and printing 
was conducted, prints were obtained, however, scratch-like adhesion was 
observed in image portions and printing durability of only 1000 sheets or 
less could be obtained. 
The printing plate precursor P-1 in Example 23 has sufficient sensitivity 
for scanning exposure, and provides excellent printing plates even without 
post treatment after exposure. Since the sulfonic acid generating polymer 
Ip-7 in layer (b) is excellent in heat sensitivity, as a result, P-1 has 
excellent discrimination of hydrophobicity/hydrophilicity before and after 
exposure. Further, P-1 has high sensitivity, and has excellent scratch 
resistance and printing durability as compared with the conventional 
printing plate precursor M-l for heat mode exposure. 
Examples 24 to 27 
A printing plate precursor P-2 was produced as Example 24 in the same 
manner as in Example 23 except that the amount coated of a sulfonic acid 
generating polymer in layer (b) was changed to 2.0 g/m.sup.2. A printing 
plate precursor P-3 was produced as Example 25 in the same manner as in 
Example 23 except that the sulfonic acid generating polymer in the heat 
sensitive layer was changed to Ip-2 from Ip-7 and the amount coated was 
changed to 1.5 g/m.sup.2. A printing plate precursor P-4 was produced as 
Example 26 in the same manner as in Example 23 except that the sulfonic 
acid generating polymer in layer (b) was changed to Ip-8 from Ip-7 and the 
amount coated was changed to 1.2 g/m.sup.2. A printing plate precursor P-5 
was produced as Example 27 in the same manner as in Example 23 except that 
the sulfonic acid generating polymer in layer (b) was changed to a-15 from 
Ip-7 and the amount coated was changed to 1.5 g/m.sup.2. The 
weight-average molecular weights and weight reduction temperatures in TGA 
of the polymers used in layer (b) are shown below. 
Ip-7: GPC weight-average molecular weight: 50000 
TGA weight reduction temperature: 155.degree. C. 
Ip-2: GPC weight-average molecular weight: 10000 
TGA weight reduction temperature: 120.degree. C. 
Ip-8: GPC weight-average molecular weight: 25000 
TGA weight reduction temperature: 134.degree. C. 
a-15: GPC weight-average molecular weight: 30000 
10% by weight of cyclohexyl benzenesulfonate was added. 
Comparative Examples 16 to 17 
A printing plate precursor C-2 was produced as Comparative Example 16 in 
the same manner as in Comparative Example 14 except that the sulfonic acid 
generating polymer in layer (b) was changed to Ip-2 from Ip-7 and the 
amount coated was changed to 1.5 g/m.sup.2. A printing plate precursor C-3 
was produced as Comparative Example 17 in the same manner as in 
Comparative Example 15 except that the intermediate layer of the Ti thin 
film having a thickness of 300 .ANG. to a layer (c) of a Sn thin film 
having a thickness of 100 .ANG.. 
In Examples 24 to 27 and Comparative Examples 16 to 17, image-wise laser 
exposure was conducted in the same manner as in Example 23 and Comparative 
Examples 14 to 15, and printing was conducted using the prepared printing 
plates without further treatment. The printing durability, scratch 
resistance and blemishing resistance thereof were evaluated according to 
the following standards. 
Printing durability: Faintness in the printed images was observed visually, 
and printing was continued until prints which could not be used in 
practice were obtained, and the printing number before that was counted. 
Scratch resistance: Scratch-like ink adhesion on solid portions was 
observed visually, and evaluated according to the following standard. 
.smallcircle.: No practical problem 
.times.: Unusable in practice 
Blemishing resistance: The blemishing in non-image portions was observed 
visually while changing the water-ink balance in printing, and evaluated 
according to the following standard. 
No blemishing over a very wide range of water-ink balance 
.smallcircle.: No blemishing over a wide range of water-ink balance 
.DELTA.: Some blemishing depending on the water-ink balance 
Evaluation results are shown in Table 9. 
TABLE 9 
__________________________________________________________________________ 
Structure of printing plate precursor 
Heat 
Intermediate sensitive 
layer layer 
component polymer Exposure Printing result 
(film (amount 
energy Printing 
Scratch 
Blemishing 
Form plate No. thickness) coated) concentration durability resistance 
resistance 
__________________________________________________________________________ 
P-2 Ti 1p-7 175 mJ/cm.sup.2 
10000 or 
.smallcircle. 
.circleincircle. 
(Example 24) (150 .ANG.) (2 g/m.sup.2) more 
P-3 Al 1p-2 250 mJ/cm.sup.2 10000 or .smallcircle. .circleincircle. 
(Example 25) (100 .ANG.) (1.5 more 
g/m.sup.2) 
P-4 Sn 1p-8 300 mJ/cm.sup.2 10000 or .smallcircle. .circleincircle. 
(Example 26) (50 .ANG.) (1.2 more 
g/m.sup.2) 
P-5 Ti a-15 300 mJ/cm.sup.2 10000 or .smallcircle. .smallcircle. 
(Example 27) (700 .ANG.) (1.5 more 
g/m.sup.2) 
C-2 None 1p-2 1000 mJ/cm.sup.2 
Whole surface is blemished and no 
(Comparative (1.5 image is obtained. 
example 16) g/m.sup.2) 
C-3 Sn None 600 mJ/cm.sup.2 
1000 x .DELTA. 
(Comparative (100 .ANG.) 
example 17) 
__________________________________________________________________________ 
Example 28 
A coating solution having the composition described below was coated as 
layer (c) on a substrate so that the weight coated was 0.3 g/m.sup.2, 
then, the same layer (b) as in Example 23 was provided. A plate precursor 
P-6 was obtained as Example 28. Then, P-6 was exposed image-wise with 
scanning using a YAG laser optical system having an oscillation wavelength 
of 1064 nm, a beam diameter of 20 .mu.m and an energy at the plate surface 
of 500 mW under conditions where the energy concentration was 350 
mJ/cm.sup.2. The obtained plate could be immediately subjected to offset 
printing to obtain 10000 or more sheets of excellent positive prints. 
______________________________________ 
Carbon black water dispersion 
1.5 g 
(solid content: 34.4% by weight) 
Polyvinylpyrrolidone 1.5 g 
(GPC weight-average molecular weight: 10000) 
Water 100 g 
Dimethylacetamide 20 g 
______________________________________ 
It was recognized that the printing plate precursors of Examples 24 to 28 
having layers (b) and (c) have a high sensitivity to IR laser exposure, 
and provide a printing plate having excellent printability without post 
treatment after exposure, as is apparent from Table 9 and Example 28. 
Example 29 
The above-described printing plate precursors P-1 to P-6 were produced and 
(A): some of them were exposed to a fluorescent light for 6 hours, (B): 
some of them were kept at a temperature of 45.degree. C. and a humidity of 
75% for 3 days, and (C) some of them were kept at a temperature of 
60.degree. C. and a humidity of 25%. All of them were exposed by laser, 
and printing evaluation was conducted. In the printing plate precursors 
exposed to conditions (A) to (C), no change was recognized in both drawing 
line width (sensitivity) and printability as compared with those directly 
after production and before exposure. 
The planographic printing plate precursor of the present invention has 
sufficient scanning exposure sensitivity for practical use, and can 
provide a planographic printing plate having excellent printing 
durability, scratch resistance, and blemish resistance, without post 
treatment after exposure. Further, the planographic printing plate 
precursor of the present invention is a planographic printing plate 
precursor excellent in storage stability. The method for producing a 
planographic printing plate of the present invention is simple and 
excellent in environmental aspects since it requires no post treatment, as 
compared with conventional production methods.