Method for developing a waterless light-sensitive lithographic plate

A method of developing a waterless light-sensitive lithographic printing plate having a support and, provided thereon, a light-sensitive layer comprising a diazo resin and a silicone gum layer with a developer is disclosed. The developer comprises an organic carboxylic acid or salt thereof, water, and at least one of a sulfite and a surfactant.

FIELD OF THE INVENTION 
This invention relates to a method of developing a waterless 
light-sensitive lithographic plate and, more particularly, to a method of 
developing a waterless light-sensitive lithographic plate, which is high 
in development rate, low in environmental pollution, odor production and 
inflammability and excellent in safety. 
BACKGROUND OF THE INVENTION 
There have so far been well-known waterless light-sensitive lithographic 
plates including, for example, those comprising each a support coated 
thereon with a light-sensitive layer and an ink-repellent layer in order. 
This type of waterless light-sensitive lithographic plates are developed 
after they are exposed imagewise to light. The developers applicable 
thereto include, for example, the organic solvent type developers such as 
those detailed in Japanese Patent Examined Publication No. 54-26923/1979, 
with which waterless light-sensitive lithographic plates are developed. 
When using this type of the developer, the developments may be made at a 
satisfactory development rate on one hand, however, there raise the 
problems of inflammability, safety, or environmental pollution caused by 
the organic solvents on the other hand. 
In the meantime, as for the developers prepared by taking the 
inflammability, safety and hygiene into consideration, the well-known 
aqueous type developers including those described in, for example, 
Japanese Patent Publication Open to Public Inspection -hereinafter 
referred to as Japanese Patent 0.P.I. Publication- Nos. 60-140243/1985 and 
61-275759/1986. The techniques described therein are low in inflammability 
and excellent in safety because the developers contain water. However, 
these developers have the problem that the development efficiency is 
seriously deteriorated especially when processing a great number of plate 
materials with an automatic processor, because the development rate 
thereof is not high enough. 
The present inventors have seriously studied on the above-mentioned 
problems and, resultingly, they have discovered that the problems can be 
solved by containing an organic carboxylic acid and at least one of a 
sulfite and a surfactant. 
SUMMARY OF THE INVENTION 
It is, therefore, an object of the invention to provide a method of 
developing a waterless light-sensitive lithographic plate, which is high 
in development rate, low in environmental pollution, odor production and 
inflammability, and excellent in safety.

DETAILED DESCRIPTION OF THE INVENTION 
The above-mentioned object of the invention can be achieved in a method of 
developing a waterless light-sensitive lithographic printing plate having 
a support and, provided thereon, a light-sensitive layer comprising a 
diazo resin and a silicone gum layer with a developer, wherein said 
developer comprises an organic carboxylic acid or salt thereof, water, and 
at least one of a sulfite and a surfactant. 
The invention will now be detailed below. 
The components of the developers applicable to the invention for developing 
waterless light-sensitive lithographic plates include an organic 
carboxylic acid, a sulfite and/or a surfactant. The components thereof 
will be detailed. 
The organic carboxylic acid applicable to the invention includes, 
preferably an aliphatic or aromatic carboxylic acid having 6 to 20 carbon 
atoms. 
The typical examples of the aliphatic carboxylic acids each having 6 to 20 
carbon atoms include caproic acid, enanthylic acid, caprylic acid, 
pelargonic acid, capric acid, lauric acid, mistylic acid, palmitic acid, 
and stearic acid. Among them, the particularly preferable examples thereof 
include an alkane acid having 8 to 12 carbon atoms. Besides, either an 
aliphatic acid having a double bond in the carbon chain thereof or those 
having a branched carbon chain may also be used. 
The above-given aliphatic carboxylic acids should preferably be used in the 
form of the sodium, potassium or ammonium salts thereof so that the 
water-solubility of the aliphatic carboxylic acids may be enhanced. 
The aromatic carboxylic acids include the compounds having a benzene ring, 
a naphthalene ring or an anthracene ring substituted with an carboxyl 
group. The typical examples of the compounds include benzoic acid, 
o-chlorobenzoic acid, p-o-chlorobenzoic acid, o-hydroxybenzoic acid, p 
-hydroxybenzoic acid, o-aminobenzoic acid, p-aminobenzoic acid, 
2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic 
acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, 
1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 
2-hydroxy-1-naphthoic acid, 1-naphthoic acid and 2-naphthoic acid. Among 
them, an aromatic carboxylic acid is particularly useful. The abovegiven 
aromatic carboxylic acids should preferably be used in the form of the 
sodium, potassium or ammonium salts thereof so that the water-solubility 
thereof can be enhanced. 
The organic carboxylic acids or salts thereof should be added into the 
developers of the invention, in an amount within the range of, preferably, 
0.1 wt% to 10 wt% and, preferably, 0.5 wt% to 4 wt%. 
The sulfite usefully applicable to the invention includes, for example, 
sodium sulfite, potassium sulfite, lithium sulfite and ammonium sulfite. 
The sulfite is contained in the developer in an amount within the range of 
0.1 to 10% by weight. 
The surfactant preferably useful includes, for example, an anionic or 
nonionic surfactant. 
The anionic surfactant includes, for example; a higher alcohol having 
C.sub.8 to C.sub.22 ; sulfates such as sodium lauryl alcohol sulfate, 
sodium cetyl alcohol sulfate, ammonium lauryl alcohol sulfate, `T-Pole 
B-81`, a brand-name, manufactured by Shell Chemical Co., and secondary 
sodium alkylsulfate; aliphatic alcohol phosphates such as the sodium salts 
of cetyl alcohol phosphate; alkylaryl sulfonates such as sodium 
dodecylbenzene sulfonate, sodium isopropylnaphthalene sulfonate, sodium 
dinaphthalene sulfonate and sodium metanitrobenzene sulfonate; alkylamide 
sulfonates such as 
##STR1## 
and the sulfonic acid salts of dibasic aliphatic acid esters, such as 
sodium sulfosuccinic acid dioctyl ester and sodium sulfosuccinic acid 
dihexyl ester. Among them, the sulfonic acid salts should preferably be 
used in particular. 
The content of the anionic surfactant is within the range of 1 wt% to 30 
wt% and, preferably, 3 wt% to 15 wt%, each to the whole amount of a 
developer used. 
Various types of the nonionic surfactants may be used therein. 
In other words, the nonionic surfactants may roughly be classified into two 
types, namely, a polyethylene glycol and a polyhydric alcohol. In the 
invention, any one of these two types of them may be used. From the 
viewpoint of obtaining a greater effect, a polyethylene glycol is 
preferably used as a nonionic surfactant. 
Among them, it is preferable to use a nonionic surfactant having three or 
more ethylene oxide groups, i.e., --CH.sub.2 CH.sub.2 O--groups, and a 
value of hydrophilic lipophile balance, abbreviated to HLB, of 5 to 20 
and, preferably, 8 to 20. 
Among the nonionic surfactants, those having both of an ethyleneoxy group 
and a propylene oxide group are particularly preferable. Further, among 
them, those having an HLB value of 8 to 20 preferable. 
The preferable examples of the nonionic surfactants applicable to the 
invention include the compounds represented by the following formulas 1 
through 8. 
Formula 1 
EQU R--O--(CH.sub.2 CH.sub.2 O)n.sup.H 
Formula 2 
##STR2## 
Formula 3 
##STR3## 
Formula 4 
##STR4## 
Formula 5 
##STR5## 
Formula 6 
EQU HO(C.sub.2 H.sub.4 O).sub.a --(C.sub.3 H.sub.6 O).sub.b --(C.sub.2 H.sub.4 
O)c.sup.H 
Formula 7 
##STR6## 
Formula 8 
EQU HO--(CH.sub.2 CH.sub.2 O)n.sup.H 
In Formulas 1 through 8, R represents a hydrogen atom or a monovalent 
organic group. The organic groups include, for example; an alkyl group 
which may have a straight-chained or branched substituent having 1 to 30 
carbon atoms, such as an aryl group, e.g., a phenyl group; an 
alkylcarbonyl group comprising an alkyl component that is the 
above-mentioned alkyl group; and a phenyl group which may have a 
substituent such as a hydroxyl group or such an alkyl group as mentioned 
above. 
In the above-given formulas, a, b, c, m , n, x and y are each an integer of 
1 to 40. 
Now, the typical examples of the non-ion type surfactants applicable to the 
invention will be given below. 
Namely, polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene 
nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, 
polyoxyethylene behenyl ether, polyoxyethylene polyoxypropylene cetyl 
ether, polyoxyethylene polyoxypropylene behenyl ether, polyoxyethylene 
nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene 
stearyl amine, polyoxyethylene oleyl amine, polyoxyethylene stearic acid 
amide, polyoxyethylene oleic acid amide, polyoxyethylene castor oil, 
polyoxyethylene abietic ether, polyoxyethylene lanolin ether, 
polyoxyethylene monolaurate, polyoxy ethylene monostearate, polyoxy 
ethylene glyceryl monoaurate, polyoxyethylene glycermonostearate, 
polyoxyethylene propyleneglycol monostearate, oxyethyleneoxypropylene 
block polymer, distyrenophenol polyethylene oxide adduct, tribenzylphenol 
polyethylene oxide adduct, octylphenol polyoxyethylene polyoxypropylene 
adduct, glycerol monostearate, sorbitan monolaurate, and polyoxyethylene 
sorbitan monolaurate. 
The weight average molecular weight of the non-ion type surfactants 
applicable to the invention is within the range of, preferably, 300 to 
10000 and, particularly, 500 to 5000. The concentration of the non-ion 
type surfactants in a developer is within the range of 0.001 to 20 wt%. 
When it is less than 0.001 wt%, any noticeable effects can be obtained. 
The particularly preferable concentration of the non-ion type surfactants 
on as developer is within the range of 0.1 to 10 wt%. 
The non-ion type surfactants may be used independently or in combination. 
In the invention, sulfites and the surfactants may be used independently or 
in combination. 
The water-contents thereof is within the range of 20 wt% to 97 wt% and, 
preferably, 50 wt% to 95 wt%. 
As the developers applicable to the invention, an alkaline aqueous type 
developers may preferably be used. The pH values of the developers are not 
lower than 10 and, preferably, within the range of pH 11.5 to 13.0. 
For the purpose of making the developers alkaline to have a pH of not lower 
than 10, it is allowed to use, for example; silicates such as sodium 
silicate and potassium silicate; inorganic alkali agents such as potassium 
hydroxide, sodium hydroxide, lithium hydroxide, tertiary sodium phosphate, 
secondary sodium phosphate, tertiary potassium phosphate, secondary 
potassium phosphate, tertiary ammonium phosphate, secondary ammonium 
phosphate, sodium metasilicate, sodium bicarbonate, sodium carbonate, 
potassium carbonate, and ammonium carbonate; organic alkali agents such as 
a mono- or di-triethanolamine and tetraalkyl hydroxide; and organic 
ammonium silicate. Among them, silicates are preferably used. 
Silicates are contained in an amount within the range of 0.1 to 20% by 
weight in the developer of the invention. 
It is preferable that the developers of the invention further contain an 
organic solvent in a proportion within the range of 0.1 to 20 wt%. 
The preferable organic solvents include at least one selected from the 
group consisting of alcohols such as methanol, ethanol and benzyl alcohol; 
amines such as methylamine, ethylamine and diethanolamine; ethylene 
glycols such as diethylene glycol and triethylene glycol; and propylene 
glycols such as .alpha.-propylene glycol and .beta.-propylene glycol. 
Benzyl alcohol or propylene glycol is more preferable. 
To the developers applicable to the invention, the following additives may 
be added; namely, neutral salts such as NaCl, KCl and KBr each described 
in Japanese Patent 0.P.I. Publication No. 58-75152/1983; chelating agents 
such as EDTA and NTA each described in Japanese Patent 0.P.I. Publication 
No. 58-190952/1983; Complexes such as [CO(NH.sub.3).sub.6 ]Cl and 
COCl.sub.2 .multidot.6H.sub.2 O each described in Japanese Patent 0.P.I. 
Publication No. 59-121336/1984; anionic or amphoteric surfactants such as 
sodium alkylnaphthalene sulfonate and N-tetradecyl-N,N-dihydroxyethyl 
betaine each described in Japanese Patent 0.P.I. Publication No. 
50-51324/1975; non-ion type surfactants such as tetramethyl decynediol 
described in U.S. Pat. No. 4,374,920; cationic polymers such as quaternary 
methyl chloride compounds of p-dimethylaminomethyl polystyrene described 
in Japanese Patent 0.P.I. Publication No. 55-95946/1980; amphoteric high 
molecular electrolytes such as a copolymer of vinylbenzyltrimethyl 
ammonium chloride and sodium acrylate described in Japanese Patent 0.P.I. 
Publication No. 56-142528/1981; reducible inorganic salts such as sodium 
sulfite described in Japanese Patent 0.P.I. Publication No. 
57-192952/1982; Inorganic lithium compounds such as lithium chloride 
described in Japanese Patent 0.P.I. Publication No. 58-59444/1983; organic 
lithium compounds such as lithium benzoate described in Japanese Patent 
Examined Publication No. 50-34442/1975; organic metal surfactants each 
containing silica or titanium described in Japanese Patent 0.P.I. 
Publication No. 59-75255/1984; organic boron compounds described in 
Japanese Patent 0.P.I. Publication No. 59-84241/1984; and quaternary 
ammonium salts such as tetraalkyl ammonium oxide described in European 
Patent No. 101010. 
In the light-sensitive layers suitably treated with the developers of the 
invention, a diazo compound is used. 
In the invention, the following diazo compounds may be used. For example, 
they include, typically, diazo resins such as a condensate of an aromatic 
diazonium salt and formaldehyde and, particularly, the salts of the 
condensate of p -diazodiphenylamine and formaldehyde or acetaldehyde; such 
as the inorganic salts of diazo resin which are the reacted products of 
the above-mentioned condensates and a hexafluorophosphate, a 
tetrafluoroborate, a perchlorate or a periodate; and the organic salts of 
diazo resin which are the reacted products of the above-mentioned 
condensates and sulfonic acids, such as those described in U.S. Pat. No. 
3,300,309. It is preferable that the diazo resins are used together with a 
binder. As for the binders, various kinds of high molecular compounds may 
be used. They include, preferably, copolymers obtained by copolymerization 
of monomers having an aromatic hydroxyl group such as those described in 
Japanese Patent 0.P.I. Publication No. 54-98613/1979 with other monomers. 
The monomers having an aromatic hydroxyl group include, for example; 
N-(4-hydroxyphenyl)methacrylamide, N-(4-hydroxyphenyl)methacrylamide, o-, 
m- or p-hydroxystyrene, or o-, m- or p-hydroxyphenyl methacrylate; 
polymers each containing a hydroxyethyl acrylate unit or a hydroxyethyl 
methacrylate unit as the main repetition unit thereof, natural resins such 
as shellac and rosin, and polyvinyl alcohol, each described in U.S. Pat. 
No. 4,123,276; polyamide resins such as those described in U.S. Pat. No. 
3,751,257; linear polyurethane resins, phthalate resins of polyvinyl 
alcohol, epoxy resins condensed with Bisphenol A and epichlorohydrin, and 
cellulose such as cellulose acetate and cellulose acetatephthalate, each 
described in U.S. Pat. No. 3,660,097. 
The light-sensitive layers contain, besides the above, the following dyes 
and substances; namely, the dyes for visualizing an image after an 
exposure or development is made, including the triphenyl methane type or 
the diphenyl methane type dyes such as Victoria Pure Blue BOH manufactured 
by Hodogaya Chemical Industries Co. and Oil Blue #603 manufactured by 
Orient Chemical Industries Co.; and the substances capable of producing an 
acid upon making an exposure to light, i.e., the photochemical acid 
producers, including light-sensitive diazo compounds, o-naphthoquinone 
diazide compounds and the aromatic compounds each having a trihalomethyl 
group such as an oxadiazole compound having a trihalomethyl group and a 
s-triazine compound having a trihalomethyl group. For further details 
thereof, refer to Japanese Patent 0.P.I. Publication No. 62-112162/1987. 
The light-sensitive layers are further allowed to contain, for example; 
alkyl ether such as ethyl cellulose and methyl cellulose, fluorine type 
surfactants and ninionic type surfactants such as PLURONIC L64 
manufactured by Asahi Electrochemical Industries Co., each for improving 
the coatability of the layers; plasticizers such as polyethylene glycol, 
tricresyl phosphate and acrylic acid or methacrylic acid polymers; and 
stabilizers such as phosphoric acid. 
The silicone rubbers applicable to the invention include, preferably, those 
having each linear organic polysiloxane as the main component, a hydroxyl 
group in the principal chain having a molecular weight of tens of hundreds 
to hundreds of thousands and the repetition unit represented by the 
following formula I, or at the end of the principal chain. 
Formula I 
##STR7## 
wherein n is an integer of not less than 2; and R represents an alkyl 
group having 1 to 10 carbon atoms, a halogenoalkyl group, an alkoxyl 
group, a vinyl group, an aryl group or a silanol group, i.e., an OH group; 
provided, not less than 60% of R is preferable to be a methyl group. In 
the formula, the silanol group, i.e., the OH group, may be attached to 
either inside or the end of the principal chain, provided, it is 
preferable that the silanol group is attached to the end of the principal 
chain. 
The silane coupling agents or the silicone cross coupling agents applicable 
to the invention are the silane compounds represented by the following 
formula: 
EQU R.sub.n SiX.sub.4-n 
wherein n is an integer of 1 to 3; R represents an alkyl group, an aryl 
group, an alkenyl group, or the monovalent group combined thereof, 
provided, these groups may have a functional group such as those of 
halogen, amine, hydroxy, alkoxy, aryloxy and thiol; X represents a 
substituent such as those of --OH, --OR.sup.2, --OAc, 
##STR8## 
H each the same as the above-denoted R, and R.sup.2 and R.sup.3 may be the 
same with or the different from each other; and Ac represents an acetyl 
group. 
In other words, the silicone rubber useful in the invention can be obtained 
through the condensation reaction of the silicone base polymer with a 
silicone cross coupling agent such as those given above. 
The silane coupling agents applicable to the invention include, typically, 
HN (CH.sub.2).sub.3 Si(OMe).sub.3 ].sub.2, vinyltriethoxysilane, 
Cl(CH.sub.2).sub.3 Si(OMe).sub.3, CH.sub.3 Si(OAc).sub.3, 
HS(CH.sub.2).sub.3 Si(OMe).sub.3, and 
vinyltris(methylethylketooxime)silane. 
The above-mentioned silicone rubber are available on the market as 
commercial articles such as YE-3085 manufactured by Toshiba Silicone Co. 
The other useful silicone rubber may be obtained through the reaction of 
the foregoing base polymer with silicone oil having a repetition unit 
represented by the following formula II, the addition reaction thereof 
with a silicone base.polymer in which about 3% of R is a vinyl group, or 
the reaction of the silicone oil with each other. 
Formula II 
##STR9## 
wherein R is synonymous with R representing the substituent of the polymers 
in Formula I; m is an integer of not less than 2; and n is an integer of 0 
or not less than 1. 
For obtaining the silicone rubber through the cross coupling reaction such 
as mentioned above, the cross coupling reaction is carried out with a 
catalyst. The catalysts applicable thereto include, for example, the 
organic carboxylates of metals such as tin, zinc, cobalt, lead, calcium 
and manganese. To be more concrete, tin dibutyllaurate, tin(II) octate or 
cobalt naphthenate, or chloroauric acid. 
For the purpose of obtaining a silicone rubber having a resistance against 
friction produced in printing operations by improving the strength of the 
silicone rubber, a filler may be mixed in. Silicone rubber mixed in 
advance with a filler therein are available on the market in the forms of 
a silicone rubber stock and a silicone rubber dispersion. In the case 
where it is preferable that a silicone rubber layer is obtained by a 
coating operation as in the invention, an RTV or LTV silicone rubber 
dispersion is preferably used. The examples thereof include, for example, 
the silicone rubber dispersions for paper coating such as Syl Off 23, 
SRX-257 and SH237, manufactured by Toray Silicone Co. 
In the invention, it is preferable to use a condensation cross coupling 
type silicone rubber. 
For further improving the adhesive property, it is preferable to contain a 
silane coupling agent having an amino group into a silicone rubber layer. 
The preferable silane coupling agents include, for example; 
(a) H.sub.2 NCH.sub.2 CH.sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3, 
(b) H.sub.2 NCE.sub.2 CH.sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.2 
(CH.sub.3), and 
(c) H.sub.2 N(CH.sub.2).sub.3 Si(OEt).sub.3 
The silicone rubber layer applicable to the invention is further allowed to 
contain a small amount of a photosensitizer. 
The silicone rubber layer applicable to the invention is coated and then 
dried on a light-sensitive layer, after the silicone rubber is dissolved 
in a suitable solvent. 
The support of the invention should preferably have a flexibility suitable 
for setting it to an ordinary lithographic printer and a resistance 
against a load applied when carrying out a printing operation. The 
supports include, for example, a sheet of metal, paper, plastic film or 
glass, each plated or vacuum evaporated thereon with a metal such as 
chromium, zinc, copper, nickel, aluminium and iron; and a sheet of paper 
coated with a resin or pasted with a foil of a metal such as aluminium. 
Among them, one of the preferable supports is an aluminium plate. 
There is no special limitation to the treatments on the supports themselves 
for improving the above-mentioned adhesive property thereof, and the 
treatments include, for example, a variety of the surface roughening 
treatments. 
The supports are allowed each to have a primer layer. The primer layers 
include, for example, those of a polyester resin, a vinyl chloride-vinyl 
acetate copolymer, an acryl resin, a vinyl chloride resin, a polyamide 
resin, a polyvinyl butyral resin, an epoxy resin, an acrylate type 
copolymer, a vinyl acetate type copolymer, a phenoxy resin, a polyurethane 
resin, a polycarbonate resin, a polyacrylonitrile butadiene, and a 
polyvinyl acetate. The above-given primer layers may be added by a 
compound capable of producing an acid when the above-mentioned exposure is 
made, or a dye discolored or faded by an acid. 
The anchoring agents constituting the above-mentioned primer layer include, 
for example, the above-mentioned silane coupling agent and a silicone 
primer and, besides, an organic titanate is also useful for this purpose. 
The thicknesses of each layers constituting the lithographic plates of the 
invention are as follows: The thicknesses of the supports are within the 
range of 50 to 400 .mu.m and, preferably, 100 to 300 .mu.m; the 
thicknesses of the light-sensitive layers are within the range of 0.05 to 
10 .mu.m and, preferably, 0.5 to 5 .mu.m; and the thicknesses of the 
silicone rubber layers are within the range of 0.1 to 10 .mu.m and, 
preferably, 0.5 to 2 .mu.m. 
In the invention, if required, a protective layer may be provided onto the 
silicone rubber layer. 
As the methods in which the above-mentioned light-sensitive lithographic 
printing plates are developed with the developer of the invention, it is 
allowed to use the methods such as a shower development method and a 
dipping development method, each having been well-known in the 
developments of light-sensitive lithographic printing plates such as a PS 
plate; provided, however, it is preferable to rub the plate surface with a 
brush or a sponge either in the course of a development or in one of the 
post processing steps of the development, such as a dyeing or washing 
step. 
The developers are generally used with circulating them and replenishing a 
part of them when it is fatigued. On the other hand, there is also a 
method in which a substantially fresh developer is supplied onto a plate 
every time when processing light-sensitive lithographic plates to develop 
the plate and the developer is then throw it away. 
The developing temperatures are within the range of 15.C to 45.degree. C. 
and, preferably, 25.degree. C. to 35.degree. C. The developing time is 
within the range of 15 seconds to 150 seconds and, preferably, 20 seconds 
to 60 seconds. 
EXAMPLES 
Now, the invention will be detailed with reference to the following 
examples. It is, however, to be understood that the invention shall not be 
limited thereto. 
EXAMPLES 1 TO 6 AND COMATIVE EXAMPLES 1 TO 3 
The following primer layer was coated on a 0.3 .mu.m-thick aluminium plate 
and was then heat-treated at 200.degree. C. for 2 minutes, so that a 
primer layer having a dried thickness of 3 .mu.m could be prepared. 
______________________________________ 
Composition of the primer layer 
______________________________________ 
Polyurethane resin, Sanprene LQ-T 1331, 
100 wt. parts 
manufactured by Sanyo Kasei 
Industries Co. 
Block isocyanate, Takenate B 830, 
20 wt. parts 
manufactured by Takeda Phermaceutical 
Industrial Co. 
Epoxy.phenol.urea resin, ST 9372, 
8 wt. parts 
manufactured by Kansai Paint Co. 
Dimethylformamide 725 wt. parts 
______________________________________ 
On the resulting primer layer, the following light-sensitive layer was 
successively coated so that the light-sensitive layer could be 2 .mu.m in 
dry thickness. 
______________________________________ 
Composition of light-sensitive layer 
______________________________________ 
Hexafluorophosphate of the paraformaldehyde 
0.5 wt. parts 
condensate of p-diazodiphenyl amine 
A copolymer of N-(4-hydroxyphenyl)meth- 
5 wt. parts 
acrylamide: acrylonitrile: ethylacrylate: meth- 
acrylic acid = 27:33:41:6 in the ratio by weight; 
Acid value = 80 
Tartaric acid 0.05 wt. parts 
Victoria Pure Blue BOH, a dye, manufactured by 
0.1 wt. parts 
Hodogaya Chemical Industries Co. 
______________________________________ 
Next, a 10% n-hexane dilluted silicone solution having the following 
composition was coated on the light-sensitive layer so that the dry 
thickness of the coat could be 2 .mu.m. 
______________________________________ 
Silicone rubber layer 
______________________________________ 
Dimethyl polysiloxane, having a molecular weight 
100 wt. parts 
of about 80000 
Methyltriacetoxy silane 5 wt. parts 
Tin dibutylacetate 0.2 wt. parts 
______________________________________ 
An original document film was brought into close contact with the resulting 
plate, and it was exposed to a 2 KW high-pressure mercury vapour lamp for 
30 seconds. 
Next, the resulting printing plate was rubbing-developed with a sponge and 
with the developer shown in Table-1, until an image was reproduced. The 
results thereof are shown in Table -1. 
TABLE 1 
______________________________________ 
Part Developing 
Composition of 
by time 
Developer weight required 
______________________________________ 
Inven- 
Inventive Potassium sulfite 
2.5 4.8 
tion Example-1 Benzoic acid 3.0 minutes 
Potassium hydroxide 
1.5 
Water 93.0 
Inventive Sodium 2.5 4.5 
Example-2 dibutylnaphthalenesul- 
minutes 
fonate 
Benzoic acid 3.0 
Potassium hydroxide 
1.5 
Water 93.0 
Inven- 
Inventive Sodium 2.5 3.8 
tion Example-3 dibutylnaphthalenesul- 
minutes 
fonate 
p-tert-butylbenzoate 
3.0 
Potassium hydroxide 
1.5 
Water 93.0 
Inventive Sodium 2.5 5.5 
Example-4 dibutylnaphthalenesul- 
minutes 
fonate 
Caprylic acid 3.0 
Potassium hydroxide 
1.5 
Water 93.0 
Inventive Sodium laurylsulfate 
1.8 4.0 
Example-5 Sodium 2-hydroxy-3- 
3.0 minutes 
naphthoate 
Benzyl alchohol 
0.4 
Potassium hydroxide 
0.8 
Water 94.0 
Inventive Polyoxyethylene 
0.1 3.0 
Example-6 lauryl ether minutes 
p-tert-butylbenzoate 
1.4 
Potassium hydroxide 
1.0 
Potassium sulfite 
2.0 
Potassium 3.0 
metasilicate 
Water 92.5 
Com- Compara- p-tert-butylbenzoate 
3.0 7.0 
pari- tive Potassium hydroxide 
1.5 minutes 
son Example-1 Water 95.5 
Compara- Sodium 3.0 7.0 
tive dibutylnaphthalenesul- 
minutes 
Example-2 fonate 
Potassium hydroxide 
0.7 
Water 96.3 
Compara- Potassium sulfite 
3.0 7.5 
tive Potassium hydroxide 
0.3 minutes 
Example-3 Water 96.3 
______________________________________ 
As is obvious from Table-1, the developer No. 1 to 6 of the invention have 
almost no odor and are high in safety, because they do not contain any 
organic solvent. They are also high in development rate, although they are 
of the aqueous type. On the other hand, the developer No. 1 to No. 3 of 
the comparative examples are not satisfactory in development rate and not 
suitable for a mass and continuous processing treatment, though they have 
a cold odor and are good in safety. 
EXAMPLE 7 
An original document film was superposed on the same waterless printing 
plate as used in Example 1 and an exposure was then made for 50 seconds to 
a 3 KW metal halide lamp from a distance of 70 cm. Next, the exposed 
light-sensitive lithographic printing plate was processed at random for 50 
seconds with the following developer B. When trying a printing operation 
by putting the resulting light-sensitive lithographic printing plate on a 
printer, an excellent printed matter without having any stained background 
could be obtained. 
______________________________________ 
Developer B 
______________________________________ 
Propylene glycol 10 wt. parts 
.beta.-anilinoethanol 1 wt. part 
p-tert-butylbenzoate 3 wt. parts 
Emulgen 147, a nonionic surfactant, 
0.1 wt. parts 
manufactured by Kao Corporation 
Potassium sulfite 2 wt. parts 
An aqueous potassium silicate solution, 
2 wt. parts 
having a SiO.sub.2 content of 26 wt % and a K.sub.2 O 
content of 14 wt % 
Potassium hydroxide 2 wt. parts 
Water 80 wt. parts 
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