JPH0368946A - Damping-waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To obtain the damping-waterless planographic printing plate which has excellent plate wear and image reproducibility and can be developed with an aq. developing soln. by incorporating a specific high-polymer compd. into a photosensitive layer. CONSTITUTION:The high-polymer compd. having the polymer unit expressed by formula I is incorporated into the photosensitive layer of the damping- waterless planographic printing plate formed by successively laminating the photosensitive layer contg. a quinone diazide compd. and an ink repulsing layer on a substrate, such as aluminum plate. In the formula, R<1> denotes a hydrogen atom or alkyl group which may have 1 to 10C substituent. X denotes a hydroxyl group, amino group or carboxyl group; n denotes 1 to 5 integer. X may be the same or different group when n is >=2. The content of the high-polymer compd. expressed by formula I is preferably 50 to 85wt.%.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a photosensitive lithographic printing plate that does not require dampening water, and more specifically, has excellent printing durability, good image reproducibility, Moreover, the present invention relates to a photosensitive lithographic printing plate that does not require dampening water and can be developed with an aqueous developer.

[Background of the Invention] When printing using a lithographic printing plate, printing is usually performed using dampening water during use, but in the photosensitive lithographic printing plate C that does not require dampening water, on the substrate, A layer of silicone rubber or a fluorine-containing compound is sequentially provided as a photosensitive layer and an ink repellent layer, and the resulting lithographic printing plate is
Printing is performed without using dampening water.

Recently, various kinds of such photosensitive planographic printing plates have been developed. For example, as a positive photosensitive planographic printing plate, the
26923, etc., and as negative photosensitive lithographic printing plates, JP-A-55-59466 and JP-A-56-8
Publications such as No. 0046 are known to have excellent practical performance, and in particular, Japanese Patent Application Laid-open No. 56-80046 discloses naphthoquinone-1,2-diazide-5-sulfonic acid on a substrate. A photosensitive lithographic printing plate that does not require dampening water is disclosed, which has a photosensitive layer containing a reaction product of chloride and a phenol novolak resin crosslinked with a polyfunctional isocyanate, and a silicone rubber layer as an ink repellent layer.

However, these photosensitive lithographic printing plates have a relatively brittle and hard photosensitive layer, so they are easily damaged by the stress applied to the plate surface during printing, and as the number of sheets printed increases, the photosensitive layer under the silicone rubber layer in the non-image area Damage occurs to the silicone rubber layer, and this damage spreads to the silicone rubber layer, causing problems such as reduced image reproducibility. As a result, it appears as insufficient printing durability.

Furthermore, JP-A No. 63-213848 describes a photosensitive lithographic printing plate that does not require dampening water and is constructed by sequentially laminating a photosensitive layer containing a quinonediazide compound and an ink repellent layer on a substrate. A photosensitive lithographic printing plate containing an acid derivative copolymer has been described, and it has been shown that this photosensitive lithographic printing plate has excellent stiffness resistance. When the above acrylic acid derivative copolymers are contained, there is a problem that image reproducibility and adhesion with silicone rubber are impaired.
If it is less than 0% by weight, the printing durability will be insufficient and there is room for future improvement.

Further, as the developer used in the present invention, preferably a developer containing water as a main component is used.

This water-based developer is an organic solvent-based developer that has conventionally been used as a developer for photosensitive lithographic printing plates that do not require dampening and are made by sequentially laminating a photosensitive layer containing a quinone diazide compound and an ink repellent layer. Although it is known to be advantageous in terms of safety and toxicity compared to developing solutions containing quinonediazide compounds, it has been known that quinonediazide compounds can be developed well with developing solutions whose main component is water. No dampening-required photosensitive lithographic printing plates containing a photosensitive layer were known.

Therefore, as a result of various studies regarding the above-mentioned problems, the present inventors have developed a photosensitive layer that has flexibility and improved flexibility by selecting a polymer compound to be added to the photosensitive layer. It was discovered that the resulting lithographic printing plate had excellent rigidity and image reproducibility, and could be developed using an aqueous developer, and the present invention was completed based on this finding.

[Object of the Invention] Therefore, the object of the present invention is to provide a photosensitive material that does not require dampening water and can provide a lithographic printing plate that has excellent printing durability, good image reproducibility, and can be developed with an aqueous developer. It provides a lithographic printing plate.

[Structure of the Invention] The object of the present invention is to provide a photosensitive lithographic printing plate that does not require dampening water and is formed by sequentially laminating a photosensitive layer containing a quinonediazide compound and an ink repellent layer on a substrate, wherein the photosensitive layer is as follows: This was achieved by a photosensitive lithographic printing plate that does not require dampening water and is characterized by containing a polymer compound having a polymerized unit represented by the general formula.

General formula [wherein R' represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms. X represents a hydroxyl group, an amino group or a carboxyl group, and n represents an integer of 1 to 5. Moreover, when n is 2 or more, X may be the same or different. ] Below, regarding the configuration of the present invention,
This will be explained more specifically.

A feature of the present invention is that the polymer compound added to the photosensitive layer contains a polymerized unit represented by the above general formula.

In this formula, the optionally substituted alkyl group having 1 to 10 carbon atoms represented by R1 includes a methyl group,
Examples include ethyl group, butyl group, amyl group, octyl group, decyl group, etc., and preferably methyl group.

Examples of polymer units represented by the general formula used in the present invention are shown below.

1) 2) 9) 10) 3) 4) 11) 5) 6) 12) 13) 7) 8) 14) 15) 16) The polymerized units represented by these - pattern holes [I] are
is preferably a hydroxyl group;
) or 14) is most preferred.

Examples of monomer units that can be used in combination with the polymerized unit represented by the above general formula include ethylenically unsaturated olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene, such as styrene, α-methylstyrene, Styrenes such as p-methylstyrene and p-chlorostyrene, acrylic acids such as acrylic acid and methacrylic acid, unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid, and maleic anhydride, such as diethyl maleate, maleic acid, etc. Diesters of unsaturated dicarboxylic acids such as dibutyl acid, di-2-ethylhexyl maleate, butyl fumarate, di-2-ethylhexyl fumarate, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic α-methylene aliphatic monocarboxylic acid esters such as dodecyl acid, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, and ethyl ethacrylate; Nitriles such as acrylonitrile and methacrylonitrile; For example, amides such as acrylamide; anilides such as acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide; methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether,
Vinyl ethers such as β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as 1-methyl-1-methoxyethylene, 1.1-dimethoxyethylene, 1.2-dimethoxyethylene, 1.
1-dimethoxycarbonylethylene, 1-methyl-1-
Ethylene derivatives such as ditroethylene, such as N-vinylpyrol, N-vinylcarbazole,
Vinyl monomers such as N-vinyl compounds such as N-vinylindole, N-vinylpyrrolidone, and N-vinylpyrrolidone; monomers having alcoholic hydroxyl groups such as hydroxyethyl acrylate and hydroxyethyl methacrylate; There are acrylic monomers having a hydroxyl group described in No. 63-213848. These hydroxyl group-containing monomers are preferably used to improve adhesion to the silicone rubber layer. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

The polymerized unit represented by the general formula used in the present invention preferably contains 10 to 90 mol%, more preferably 20 to 60 mol%, in the polymer compound. As a result, the effects of the present invention become apparent.

In the present invention, the content of the polymer compound having the polymerized unit represented by the above-mentioned pattern [I] in the photosensitive layer is preferably 20 to 95% by weight, more preferably 50 to 85% by weight.

Next, the photosensitive layer used in the present invention contains an O-quinonediazide compound. Any 0-quinonediazide compound can be used as long as it can function as a photosensitizer.

Specifically, for example, 1,2-benzoquinonediazide-4
- Condensation of sulfonyl chloride, 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2-naphthoquinonediazide-6-sulfonyl chloride and a compound containing a hydroxyl group and/or an amino group. Compounds that have been used are preferably used.

Examples of hydroxyl group-containing compounds include dihydroxybenzophenone, tetrahydroxybenzophenone, trihydroxybenzophenone, dihydroxyanthraquinone,
Examples include bisphenol A1 phenol novolac resin, resorcin benzaldehyde condensation resin, and pyrogallol acetone condensation resin. In addition, examples of amino group-containing compounds include aniline, p-aryonodiphenylamine, p-
Examples include aminobenzophenone, 4,4°-diaminodiphenylamine, 4,4'-diaminobenzophenone, and the like. Preferred quinonediazide compounds among cholerano are esters of polyhydroxybenzophenone and benzoquinone-1,2-diazide-4 or 5-sulfonic acid.

For further information on quinonediazide compounds, including those described here, please refer to "Light Sensitive Systems J" by J.
sltIve 5ystea+) in New York City,
John Wiley and Sons, Inc., 1965) and Yonematsu and Inui, “Photosensitive Polymers” (Kodansha, 1977)
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The content of the quinonediazide compound in the photosensitive layer in the present invention is preferably 5% to 70% by weight, more preferably 10% to 40% by weight.

Furthermore, the photosensitive layer applicable to the present invention has a modified structure by crosslinking the mixture of the above-mentioned quinonediazide compound and the polymer compound used in the present invention with a polyfunctional compound or bonding it with a monofunctional compound. Also includes things.

Examples of the compound used to introduce the above-mentioned crosslinked structure include polyfunctional isocyanates such as para-phenylene diisocyanate, 4,4' diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, or adducts thereof; Functional epoxy compounds include, for example, polyethylene glycol diglycidyl ethers, polypropylene diglycidyl ethers, bisphenol A diglycidyl ether, trimethylolpropane triglycidyl ether, and the like.

These crosslinking reactions proceed by heating,
In order to prevent rapid thermal decomposition of the quinonediazide compound, the heating range is preferably 150° C. or lower, and a catalyst or the like is generally used. Examples of the modification method include esterification, amidation, and urethanization of the active group of the photosensitive compound. The compound reacted with the active group of the photosensitive compound may be a low-molecular compound or a relatively high-molecular compound, and a method such as graft polymerization of a monomer to the photosensitive compound may be used.

Further, the photosensitive layer used in the present invention may optionally contain polymeric compounds other than those mentioned above, such as novolak resin (phenol-formaldehyde resin, cresol-formaldehyde resin, p-tert-butylphenol-formaldehyde resin, etc.), p-tert-butylphenol-formaldehyde resin, etc. Additives such as a hydroxystyrene resin, a polymer compound such as an acrylic acid derivative copolymer described in JP-A-63-213848, a dye, a silane coupling agent, and a plasticizer can be added.

Among these polymer compounds, novolak resin is
It is preferable to add it in an amount of 5% by weight.

As the ink repellent layer used in the present invention, a silicone rubber layer is mainly used. As the silicone rubber, silicone rubber has a molecular weight of several thousand to several hundred thousand and has a repeating unit represented by the following general formula [I]. Preferably, the main component is a linear organic polydiorganocycloxane having a hydroxyl group in the chain or at the end of the main chain.

General formula [13% formula% where n is an integer of 2 or more, R is an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxyl group, a vinyl group, an aryl group, a silanol group (OH group), and % R
It is preferable that 60% or more of the methyl groups are methyl groups. The silanol group (OH group) may be located either in the main chain or at the end of the main chain, but is preferably located at the end.

The silane coupling agent (or silicone crosslinking agent) used in the present invention is R,5iX4-n (wherein, n is an integer of 1 to 3, and R is alkyl, aryl, alkenyl, or a combination thereof. It represents a monovalent group, and these groups may have a functional group such as halogen, amine, hydroxy, alkoxy, aryloxy, thiol, etc.

represents a substituent such as Here, R2 and R3 represent the same thing as R above, and R2 and R3 may be the same or different. It also represents an Acti acetyl group. ) is a silane compound represented by

The silicone rubber useful in the present invention has the formula -e [1F
It is obtained by a condensation reaction between the silicone base polymer represented by the formula and the silicone crosslinking agent.

Specific examples of the silane coupling agent used in the present invention include HN((CH2)3Si(OMe)s]z, vinyltriethoxysilane, Cj(inH2)sSi(OMe)
e) 3, CHsSl (OAC) 3, R5 (ctr
2) Examples include sSi (OMe) s, vinyltris(methylethylketoxime)silane, and the like.

The silicone rubber described above is also available as a commercial product, such as YE-3085 manufactured by Toshiba Silicone Co., Ltd. Other useful silicone rubbers can be produced by reacting the above-mentioned base polymer with a silicone oil having repeating units represented by the following general formula [II], or by reacting a silicone oil in which about 3% of R is a vinyl group. It can also be obtained by addition reaction of silicone with a base polymer or reaction of the silicone oils with each other.

(In the formula, R has the same meaning as R, which is a substituent of the polymer represented by general formula [I], m is an integer of 2 or more, and n is O or an integer of 1 or more.) Such a crosslinking reaction To obtain silicone rubber, the crosslinking reaction is carried out using a catalyst. This catalyst includes tin, zinc, cobalt, lead,
Organic carboxylates of metals such as calcium, manganese, etc.
For example, dibutyltin laurate, tin (I di-octoate, cobalt naphthenate, etc.), chloroauric acid, etc. are used.

Additionally, fillers can be mixed in to improve the strength of the silicone rubber and to obtain a silicone rubber that can withstand the frictional forces generated during printing operations. Silicone rubber mixed with filler in advance is commercially available as silicone rubber stock or silicone rubber dispersion, and when it is preferable to obtain a silicone rubber film by coating as in the present invention, RTV
Alternatively, dispersion of LTV silicone rubber is preferably used. An example of this is 53110ff 23.5RX-257,5H manufactured by Toray Silicone.
There are silicone rubber dispersions for vapor coating such as 237.

In the present invention, it is preferable to use condensation and crosslinking type silicone rubber.

The silicone rubber layer preferably contains a silane coupling agent having an amino group in order to further improve adhesiveness.

Examples of preferable silane coupling agents include the following.

(a) H2NCHzCHJH(CH2) sS i
(OCHs) 5(b) H2NCE2CI2NH(C
H2) 3si (OCH3) 2 (CL) (c))
12N(CHz)ssi(OEt)sThe silicone rubber layer used in the present invention may further contain a small amount of photosensitizer.

The silicone rubber layer used in the present invention is prepared by dissolving silicone rubber in a suitable solvent, applying the solution onto the photosensitive layer, and drying and curing.

The support used in the plate material of the present invention is preferably one that is flexible enough to be set in a normal lithographic printing machine and that can withstand the load applied during printing, such as metals such as aluminum, zinc, copper, and steel. plate, and chromium, zinc, copper,
Metal plates, paper, plastic films, and glass plates plated or vapor-deposited with nickel, aluminum, iron, etc.
Examples include resin-coated paper and paper covered with metal foil such as aluminum.

Among these, aluminum plates are preferred.

The treatment for the support itself to improve the adhesion is not particularly limited, and includes various surface roughening treatments.

In addition, before coating the photosensitive layer on the support, a primer layer may be provided on the support in order to obtain sufficient adhesion between the photosensitive layer and the support. -vinyl acetate copolymer, acrylic resin,
Examples include vinyl chloride resin, boria-based resin, polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, phenoxy resin, polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, etc. .

In addition, as the anchor agent constituting the primer layer,
For example, a silane coupling agent can be used, and organic titanates and the like are also effective.

The thickness of each layer constituting the plate material of the present invention is as follows. That is, the support has a thickness of 50 to 400 μm, preferably 100 μm.
~300μm, photosensitive layer 0.05~10μm, preferably 0.5~5μm, silicone rubber layer 0.1~20μm
The thickness is preferably 0.5 to 4 μm.

In the present invention, a protective layer may be provided on the upper surface of the ink repellent layer, if necessary.

The plate material of the present invention that does not require dampening water is manufactured, for example, as follows.

A composition solution to form a photosensitive layer is applied onto a support using a conventional coater such as a reverse roll coater, an air knife coater, a Mayer percoater, or a rotary coating device such as a Whaler, and then dried.

If necessary, a primer layer is provided between the support and the photosensitive layer in the same manner as for the photosensitive layer, and then a solution capable of forming a C ink repellent layer is applied on the photosensitive layer in the same manner, It is usually heat treated at a temperature of 100 to 120° C. for several minutes to fully cure and form an ink repellent layer. If necessary, a protective film can be provided on the ink repellent layer using a laminator.

Next, a method for manufacturing a printing plate that does not require dampening water using the plate material that does not require dampening water of the present invention will be explained.

The original negative film is vacuum-adhered to the plate surface and exposed. As a light source for this exposure, a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, etc., which generate abundant ultraviolet light, are used.

Next, the negative film is peeled off and developed using a developer. As the developer, an aqueous developer is preferably used, such as one described in JP-A No. 61-275759, which contains 30% by weight or more of water, an organic solvent, and a surfactant. I can do it. More preferably, it contains an alkaline agent.

Organic solvents containing water-based developers include:
For example, aliphatic hydrocarbons (hexane, heptane, 'Isoper E, H, G' (trade name of aliphatic hydrocarbons manufactured by Esso Chemical Co., Ltd.), gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, (xylene, etc.) or halogenated hydrocarbons (triclene, etc.) k: Those to which the following polar solvents are added are suitable.

Alcohols (methanol, ethanol, 3-methyl-
3-methoxybutanol, etc.), ethers (methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carpitol, ethyl carpitol, butyl carpitol, dioxane, etc.), ketones (acetone, methyl ethyl ketone, 4-methyl-1,3-dioxolane) -2-one, etc.), esters (ethyl acetate, methyl cellosolve acetate, cellosolve acetate, carpitol acetate, etc.) The surfactants added to the developer of the present invention include anionic surfactants, nonionic surfactants, Cationic surfactants and zwitterionic surfactants are used, and specific examples include the following.

Examples of anionic surfactants include (1) higher alcohol sulfate esters (e.g. sodium salt of lauryl alcohol sulfate, ammonium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, sulfur sodium alkyl sulfate, etc.) (2) Fat Group alcohol phosphate ester salts (e.g.
(3) Alkylaryl sulfonic acid salts (e.g., dodecylbenzenesulfonic acid sodium salt, isopropylnaphthalenesulfonic acid sodium salt, dinaphthalenesulfonic acid sodium salt, metanitrobenzenesulfonic acid sodium salt, etc.) ) (4) Alkyla acido sulfonates (5) Sulfonates of dibasic aliphatic esters (e.g. sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, etc.) (6) Formaldehyde condensates of alkylnaphthalene sulfonates ( For example, a formaldehyde condensate of sodium dibutylnaphthalene sulfonate, etc.) can be mentioned.

Examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, oxyethylene oxypropylene block polymer, etc. It will be done.

Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamines, and the like.

Examples of amphoteric surfactants include alkyl betaines, and among these, anionic surfactants are suitable.

These surfactants can be used alone or in combination of two or more.

The appropriate amount of the surfactant used in the present invention is 0.5% to 60% by weight, preferably 1% to 50% by weight.

Further, the surfactant used in the present invention is preferably used together with an alkaline agent, and the alkaline agents include (1) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, or inorganic alkaline agents such as trisodium or ammonium phosphate, sodium metasilicate, sodium carbonate, ammonia, (2) mono-, di- or trimethylamine, mono-, di- or trimethylamine, mono- or diisopropylamine; Examples include organic amine compounds such as n-butylamine, mono-, di-, or triethanolamine, mono-, di-, or triisopropanolamine, ethyleneimine, and ethylenediimine.

It is also possible to dye the image area simultaneously with development by adding a dye such as crystal violet or astrazonelet to the developer.

Development can be carried out, for example, by rubbing with a developing pad containing a developer as described above, or by pouring a developer onto the printing plate and then rubbing with a developing brush.

By the above development, a printing plate is obtained in which the ink repellent layer in the exposed areas is removed and the photosensitive layer, primer layer or support is exposed, and the ink repellent layer remains in the unexposed areas.

At this time, if the photosensitive layer is not crosslinked or modified, part or all of the photosensitive layer is removed, and the exposed surface of the support or primer layer becomes a receiving area, and the photosensitive layer is removed. In the case of a photosensitive layer that has been crosslinked or modified to be insolubilized in a developer, the photosensitive layer remains with substantially no reduction in its thickness, and the exposed surface of the photosensitive layer serves as an ink receiving area. Become. The photosensitive layer used in the present invention is preferably applied to a photosensitive layer in which the photosensitive layer is removed during development, and a photosensitive lithographic printing plate that does not require dampening water and is well developed with an aqueous developer is obtained. It will be done.

[Examples] The present invention will be described below with reference to Examples, but the present invention is not limited thereto.

Example 1 [Manufacture of aluminum plate a] An aluminum plate with a thickness of 0.2 mm was degreased by immersing it in a 3% aqueous sodium hydroxide solution, washed with water, and then soaked in hydrochloric acid with a concentration of 2%.
Electrolytic etching was carried out for 10 seconds in an aqueous solution of 70 A/dm' at a temperature of 25°C, immersed in a 1% sodium hydroxide aqueous solution at a temperature of 50°C for 10 seconds, and after washing with water, etched in a 35% sulfuric acid aqueous solution at a temperature of 30°C. 5A/d at °C
Anodic oxidation was performed for 20 seconds under the conditions of m', washed with water, further immersed in water at a temperature of 85° C. for 25 seconds, washed with water, and dried to obtain aluminum plate a.

A photosensitive composition having the composition shown below was applied to an aluminum plate a, and dried at 100° C. for 2 minutes to form a photosensitive layer having a thickness of 0.5 μm.

[Photosensitive composition] (a) 20 parts of ester of 1 mol of 2,3.4-trihydroxybenzophenone and 3 mol of naphthoquinone-1,2-diazide-5-sulfonic acid (b) N-(4-hydroxyphenyl ) Methacrylic acid, acrylonitrile, ethyl acrylate, methyl methacrylate copolymer (
Composition ratio: 3°/3015/35 (-[-r ratio>)
70 parts (C) Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd., dye) 1 part (
d) 10 parts of phenol, m-p-mixed cresol and Nermaldehyde copolycondensation resin (composition ratio of phenol and cresol 40/60 (molar ratio)) (e) 900 parts of methyl cellosolve,
The following silicone rubber composition was coated on the above photosensitive layer and cured by heating at 100° C. for 10 minutes to obtain a lithographic printing plate material having a silicone rubber layer with a thickness of 1.5 μm and requiring no dampening water. .

[Silicone rubber layer composition] (a) 100 parts of dimethylpolysiloxane (molecular weight 40,000) having hydroxyl groups at both ends (b) Vinyl tris(methyl ethyl ketoxime) silane
8 parts (C) 0.1 part of γ-Ayonopropyltriethoxysilane (d) 0.2 part of dibutyltin diacetate (e
) Isopar E (manufactured by Esso) 900 parts After a negative film was vacuum-adhered to the upper surface of the above plate material, it was exposed to light using a metal halide lamp as a light source and developed using the following developer. During development, by rubbing the surface of the plate material with a developing pad, the photosensitive layer and silicone rubber layer in exposed areas were easily removed, and a printing plate with excellent dot reproducibility and shadow area reproducibility was obtained.

[Developer composition] (a) Isopar H (manufactured by Esso) 0.5 part (b) 3-
Methyl-3-methoxybutanol 20 parts (c) Potassium carbonate 0.5 part (d
) Diethanolamine 0.5 part (e) Perex NBL (manufactured by Kao Corporation, anionic surfactant 35
% aqueous solution) 20 parts (f) water
60 parts [Comparative Example-1] In place of (b) in the photosensitive composition of Example 1, 2-hydroxyethyl methacrylate, 2-ethylhexyl methacrylate copolymer (composition ratio = 80/20 (molar ratio)) ) was used in the same manner as in Example 1 to obtain a lithographic printing plate that did not require dampening water. Next, an attempt was made to develop the plate with a developer, but a printing plate with sufficient image quality could not be obtained.

[Comparative Example-2] In place of (b) in the photosensitive composition of Example 1, N-phenyl methacrylate, acrylonitrile, ethyl acrylate, methyl methacrylate copolymer (composition ratio: 30
A lithographic printing plate that does not require dampening water was obtained in the same manner as in Example 1, except that the molar ratio of /3015/35 was used. Next, an attempt was made to develop the plate with a developer, but a printing plate with sufficient image quality could not be obtained.

[Effects of the Invention] By containing a specific polymer compound in the photosensitive layer, the present invention provides excellent stiffness resistance, excellent image reproducibility, and good planographic printing that can be developed with an aqueous developer and does not require dampening water. You can get the version.

Claims (1)

[Scope of Claims] A photosensitive lithographic printing plate that does not require a dampening solution and is formed by sequentially laminating a photosensitive layer containing a quinonediazide compound and an ink repellent layer on a substrate, wherein the photosensitive layer is a polymer compound represented by the following general formula: A photosensitive lithographic printing plate that does not require dampening water and is characterized by containing a polymer compound having units. General formula ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^1 represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms. X represents a hydroxyl group, an amino group or a carboxyl group, and n represents an integer of 1 to 5. Moreover, when n is 2 or more, X may be the same or different. ]