JPH0462555A - Photosensitive composition with excellent chemical resistance - Google Patents

Abstract

PURPOSE:To improve processing chemical resistance and UV ink characteristic by using a polymer having the constitutional unit derived from specific vinyl pyrrolidone as a binder. CONSTITUTION:The binder is formed of the polymer having the constitutional unit of formula I and the constitutional unit derived from the vinyl pyrrolidone and further, at least one constitutional units of formulas iI, III and IV. In the formula I1 R1, R2 denote a hydrogen atom, halogen atom, alkyl group, aryl group or carboxyl group or the salt thereof; R3 denotes a hydrogen atom, halogen atom, alkyl group or aryl group; R4 denotes a hydrogen atom, alkyl group, aryl group or aralkyl group. Y denotes an arom. group; X denotes a bivalent org. group and n is 0 to 5 integer. In the formula II, R5 denotes a hydrogen atom, halogen atom, alkyl group or aryl group; R6 denotes an alkylene group or arylene group; X1 denotes an electron withdrawing group. In the formula III, R7 denotes a hydrogen atom, halogen atom, alkyl group or aryl group; R8 denotes an alkylene group or arylene group; X2 denotes an electron withdrawing group. In the formula TV, R9 denotes a hydrogen atom, halogen atom, alkyl group or aryl group; X3 denotes an electron withdrawing group.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photosensitive composition suitable for positive-working photosensitive lithographic printing plates, and more specifically, a photosensitive composition that has excellent treatment chemical resistance and ink receptivity. The present invention relates to a photosensitive composition suitable for positive-working photosensitive lithographic printing plates.

[Background of the Invention and Prior Art] A positive-working photosensitive lithographic printing plate generally has an ink-receptive photosensitive layer formed on a hydrophilic support, which becomes solubilized by exposure to light. When this photosensitive layer is subjected to imagewise exposure and development, the non-image areas are removed while leaving the image areas, thereby forming an image. In printing, the difference in properties of image areas being lipophilic and non-image areas being hydrophilic is utilized.

Positive-working photosensitive lithographic printing plates have low resistance to various processing chemicals used during printing, such as isopropyl alcohol contained in fountain solution, ink, surface preparation liquid, plate cleaner, etc. However, it has the disadvantage that printing durability is reduced.

Japanese Patent Publication No. 4B-28403 describes that the treatment chemical resistance was improved by using 0-naphthoquinonediazide sulfonic acid ester of a polycondensation resin of pyrogallol and acetone as a photoreceptor. It showed some good performance against the processing chemicals used in printing with conventional oil-based inks. However, in recent years, printing using ultraviolet curable UV ink has been increasing.

The processing chemicals (especially washing oil, plate cleaners, etc.) used when printing with these UV inks include:
Since it is necessary to use a more powerful treatment chemical than the above-mentioned processing chemicals, the durability of the above-mentioned photoreceptor was insufficient when ordinary novolac resins such as m-cresol novolac resins were used as the binder.

Furthermore, Japanese Patent Publication No. 58-54821 discloses a photosensitive composition containing as a binder a resin obtained by copolycondensing phenol, m- and p-mixed cresol, and aldehyde to improve processing chemical resistance. However, this resin also has extremely insufficient resistance to processing chemicals used in UV ink printing. Special Public Service 1977-
The photosensitive composition disclosed in Japanese Patent No. 28401 is described as containing a photoreceptor made of an 0-naphthoquinonediazide acid derivative and a binder made of a polymer compound containing p-hydroxymethacrylanilide or the like as a repeating structural unit. ing. Using this binder improved resistance to processing chemicals used in UV ink printing. However, it has the disadvantage of poor ink receptivity. JP-A-62-279327 discloses that by using a polymer compound having a structural unit represented by the general formula [I] as a binder, resistance to processing chemicals used in UV ink printing is improved, and ink adhesion is improved. Although it has been described that it improves meat quality, further improvements have been desired.

[Object of the Invention] Therefore, the object of the present invention is to provide a photosensitive composition suitable for a photosensitive lithographic printing plate, which has excellent treatment chemical resistance and improved UV ink characteristics without reducing ink receptivity. It's about doing.

[Structure of the Invention] The above object of the present invention is to: (1) use a polymer having at least (a) a structural unit represented by the following general formula CI] and (b) a structural unit derived from vinylpyrrolidone as a binder; A photosensitive composition characterized in that it is used.

General formula [1] (wherein R□ and R2 each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a carboxyl group, or a salt thereof, and Rff represents a hydrogen atom, a halogen atom,
represents an alkyl group or an aryl group, R4 is a hydrogen atom,
Represents an alkyl group, aryl group or aralkyl group.

Y represents an aromatic group.

X represents a divalent organic group, and n represents an integer of 0 to 5. ) (2) The polymer further has the following general formula [■], general formula [m
The photosensitive composition according to item (1) above, which is a polymer having at least one structural unit selected from structural units represented by the general formula [IV] and general formula [IV].

General formula [■CO→CH2-C+ 0-COR6XI (wherein, R5 represents a hydrogen atom, a halogen atom, an alkyl group, or an aryl group, R6 represents an alkylene group or an arylene group, and Xl represents an electron-withdrawing group. ) General formula [ml R → CH2-C+ 0-C-R, -X2 (wherein, R7 represents a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and Ra represents an alkylene group or an arylene group, X2 represents an electron-withdrawing group.) General formula [■CO1←CH2-C+ (In the formula, R9 represents a hydrogen atom, a halogen atom, an alkyl group, or an aryl group, and X represents an electron-withdrawing group. ) achieved by.

The present invention will be explained in detail below.

First, the structural unit represented by the general formula [11] of the present invention will be explained.

In the above structural unit, R1 and R7 are preferably a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, or a carboxyl group, or a salt thereof (ammonium salt and alkali metal salt), and more preferably a hydrogen atom. R
3 is preferably a hydrogen atom, a halogen atom such as a bromine atom or a chlorine atom, or an alkyl group such as a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group.

Examples of R4 include a hydrogen atom, a halogen atom such as a bromine atom and a chlorine atom, and an alkyl group such as a methyl group and an ethyl group.

Y is preferably a phenylene group or a naphthylene group which may have a substituent, and examples of the substituent include an alkyl group such as a methyl group or an ethyl group, a halogen atom such as a bromine atom or a chlorine atom, a carboxyl group or its like. Examples include salts, alkoxy groups such as methoxy and ethoxy groups, hydroxyl groups, sulfo groups, cyano groups, nitro groups, and acyl groups. More preferably, Y is an unsubstituted phenylene group or a naphthylene group having a methyl group. X is a divalent organic group connecting a nitrogen atom and an aromatic carbon, preferably an alkylene group, and n is an integer of 0 to 5, preferably an integer of 0 to 3, more preferably 0, That is, this is a case where Y and the nitrogen atom are directly bonded.

Next, general formula [■], general formula [■] and general formula [IV
The structural unit represented by ] will be explained.

In the above structural unit, R5, R, and R9 are preferably a hydrogen atom, a halogen atom such as a bromine atom or a chlorine atom, or an alkyl group such as a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group. R6 and R8 are preferably a chain or cyclic alkylene group such as a methylene group, an ethylene group, or a cyclohexylene group, which may have a substituent, or a phenylene group or a naphthylene group, which may have a substituent. Examples of the substituent include alkyl groups such as methyl and ethyl groups, and electron-withdrawing groups.

X, , X, and X represent electron-withdrawing groups.

The electron-withdrawing group refers to a group having a Hammett's σp value of 0 or less. Preferred electron-withdrawing groups include halogen atoms such as chlorine atoms, cyano groups, nitro groups, and sulfo groups.

By using the groups represented by X□, X2, and .

Below, General formula [I] General formula [■C General formula [m]
Specific examples of the structural units represented by formula [IV] and General Formula [IV] will be listed below, but the present invention is not limited thereto.

The following is a specific example of the structural unit represented by the general formula [1] in the margin -a Hff -b Hi -k Hff -g H3 The following is a specific example of the structural unit represented by the general formula [■] -+ CH2-CH+ - 1-a -b I-c -d -e Hy If Specific example of structural unit represented by general formula [] -g -a CH3 ■ Ht →CH2-C+ ■ -C H2CJ →CH2-C+- ■ 0-C-CH,CN -c CH3 →cn2-C+- 11-d CH3 →CH, -C-)- -e -f →CH2-C1- →CH, -CH+- -h →C)l, -CIH- Space below -h Space below Specific examples of structural units represented by general formula [IV] IV-a IV-b →CH2-CH-)- N →CH, -C1- J IV-c IV-d -+CH2-CH+- O2 →CH2CH+- 3O, H IV e CHz →CH, -C-)- N IV-f CH3 → CH2-C+- O2 N C# The polymer of the present invention has the general formula [I] A structural unit derived from vinylpyrrolidone, a structural unit derived from vinylpyrrolidone, and one or more structural units in addition to the structural units represented by the general formula [II] and general formula [I] and general formula [IV]. may have structural units derived from other monomers (hereinafter referred to as copolymer component structural units).

Examples of the other monomers include ethylenically unsaturated olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene; styrenes such as styrene, α-methylstyrene, p-methylstyrene, and p-chlorostyrene; For example, acrylic acids such as acrylic acid and methacrylic acid, unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid, and maleic anhydride, such as methyl acrylate, ethyl acrylate, n-butyl acrylate,
Esters of α-methylene aliphatic monocarboxylic acids such as isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, and ethyl ethacrylate. , for example, amides such as acrylamide, anilides such as acrylanilide, p-chloroacrylanilide, m-ditriacrylanilide, m-methoxyacrylanilide, such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, etc. vinyl esters such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether,
Vinyl ethers such as β-chloroethyl vinyl ether, e.g. 1-methyl-1-methoxyethylene, 1.1-
dimethoxyethylene, 1,2-dimethoxyethylene, 1
Examples include vinyl monomers such as ethylene derivatives such as 1-dimethoxycarbonylethylene, N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Structural unit represented by general formula [I], structural unit derived from vinylpyrrolidone, structural unit represented by general formula [11], structural unit represented by general formula [m], general formula [IV
] The structural unit represented by and the structural unit derived from the above monomer may be bonded in either a block or random state in the polymer.

Next, typical examples of the polymer of the present invention (hereinafter referred to as "polymer of the present invention") will be given. In addition, in the compounds exemplified below, Mw is weight average molecular weight, Mn is number average molecular weight,
S Sk % I Sm and n represent the mole % of the respective structural units.

Below margin (b) m: n: 1-50:20:30 m: n: l: k-30:20:30:20
(H) H3 m: n: 1: k-30:20:15:85m
: n: 1-40:30:30 (d) H3 man: 1: ni-30:40:10:20 (e) H3 man: 1: ni = 20:30:30:20 (h) Him: n: 1-30:40:30 *→CH2CFI to m:n:1:ni:5-20:30:20:15:15m
an: 1: ni: 5-30: 10:30:10:20
man: 1:ni:5-20:15:30:15:20
The following margins The polymer of the present invention is produced by using a monomer having a carbon-carbon unsaturated double bond, which can form each structural unit by cleavage of the carbon-carbon unsaturated double bond, using a polymerization initiator. Alternatively, it can be obtained by polymerizing with or without using a solvent.

The proportion of each structural unit forming the polymer of the present invention can be varied widely, and there is no particular restriction on the molecular weight of the polymer of the present invention.
] 10 to 30 mol% of structural units derived from vinylpyrrolidone, 15 to 30 mol% of structural units derived from vinylpyrrolidone, general formula [■
It is preferable that the structural unit represented by V] is 0 to 30 mol%, preferably 10 to 30 mol%, and the copolymer component structural unit is 0 to 50 mol%, and the weight average molecular weight is 5.
OX 10' to 1.0×105, especially 5. OX
10'~4. Ox 10' is preferred.

In addition, the molecular weight of the polymer in this invention is measured by GPC (gel permeation chromatography method).

The proportion of the polymer of the present invention in the photosensitive composition is 30 to
95% by weight is preferred, and 50-85% by weight is particularly preferred.

The photosensitive composition of the present invention contains a photosensitive component. As the photosensitive component, an 0-quinonediazide compound can be used.

Examples of the 0-quinonediazide compound include ester compounds of 0-naphthoquinonediazide sulfonic acid and polycondensation resins of phenols and aldehydes or ketones.

Examples of the phenols include phenol, 0-
Cresol, m-cresol, p-cresol, 3.5
- Monohydric phenols such as xylenol, carvacrol, and thymol, dihydric phenols such as catechol, resorcinol, and hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred among these are formaldehyde and benzaldehyde. Further, examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol formaldehyde resin, m-cresol formaldehyde resin, m- and p-mixed cresol formaldehyde resin, resorcin benzaldehyde resin, pyrogallol acetone resin, and the like.

Said. - The condensation rate of 0-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol of the naphthoquinonediazide compound (reaction rate with respect to one OH group) is 15 to 80%.
is preferable, and more preferably 20 to 45%.

Further, as the O-quinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be used. That is, for example, known 1,2-benzoquinonediazide sulfonic acid ester, 1°2-naphthoquinonediazide sulfonic acid ester, 1,2-benzoquinonediazide sulfonic acid amide, 1.2-naphthoquinonediazide sulfonic acid amide, etc. Quinonediazide compounds, more specifically J. Kossar
``Light Sensitive System'' (L
1ght-Sensit1ve Systems)
No. 339-352 (1985) 'Photoresist J' by John Viley & Sons (=z-York) and W.S. DeForest ) Volume 50 (1
975), McGrav-Hill I
) 1,2-benzoquinonediazide-4-sulfonic acid phenyl ester, 1,
2-Benzoquinonediazide-5-sulfonic acid phenyl ester, 1.2.1', 2'-di(benzoquinonediazide-4-sulfonyl)-dihydroxybiphenyl, 1
,2-benzoquinonediazide-4-(N-ethyl-N-
β-naphthyl)-sulfonamide, 1,2-naphthoquinonediazide-4-sulfonic acid cyclohexyl ester,
1.2-naphthoquinonediazide-5-sulfonic acid cyclohexyl ester, 1-(1,2-naphthoquinonediazide-5-sulfonyl)-3,5-dimethylpyrazole, 1,2-naphthoquinonediazide-4-sulfonic acid-4
'-Hydroxydiphenyl-4'-azo-β-naphthol ester, N.

N-di(1,2-naphthoquinonediazide-5-sulfonyl)-aniline, 2'-(1,2-naphthoquinonediazide-4-sulfonyloxy)-1-hydroxy-anthraquinone, 1,2-naphthoquinonediazide-4- Sulfonic acid-2,4-dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-4-sulfonic acid-
2,3,4-trihydroxybenzophenone ester,
1゜Condensation product of 2 moles of 2-naphthoquinonediazide-4-sulfonic acid chloride and 1 mole of 4,4'-diaminobenzophenone, 2 moles of 1.2-naphthoquinonediazide-4-sulfonic acid chloride and 4,4'-dihydroxy- 1,1'
- condensate of 1 mole of diphenylsulfone, condensate of 1 mole of 1,2-naphthoquinone diazide 4-sulfonic acid chloride and 1 mole of purbrogalin, 1,2-naphthoquinone diazido-5-sulfonic acid-4'-hydroxydiphenyl- 4'-azo-β-naphthol ester, 2'(1,2
-naphthoquinonediazide-5-sulfonyloxy)-1
-Hydroxy-anthraquinone, 1,2-naphthoquinonediazide-5-sulfonic acid-2,4-dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-
5-sulfonic acid-2,3,4-trihydroxybenzophenone ester, 1,2-naphthoquinone diazide-5-
Condensate of 2 moles of sulfonic acid chloride and 1 mole of 4,4'-diaminobenzophenone, 2 moles of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mole of 4,4'-dihydroxy-1,1'-diphenylsulfone. A condensate of 1 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mol of purbrogalin, 1,2-
Examples include 1,2-quinonediazide compounds such as naphthoquinonediazide-5-(N-dihydroabiethyl)sulfonamide. In addition, the special public service 1953-1953
No. 37-3627, No. 37-13109, No. 4
No. 0-26126, No. 40-3801, No. 45-56
No. 04, No. 45-27345, No. 51-13013, JP-A No. 48-98575, No. 48-63802,
The 1,2-quinonediazide compounds described in each publication of No. 48-63802 can also be mentioned.

Among the above 0-quinonediazide compounds, 0- obtained by reacting 1,2-penzoquinonediazide sulfonyl chloride or 1,2-naphthoquinonediazide sulfonyl chloride with pyrogallol acetone condensation resin or 2,3°4-trihydroxybenzophenone Quinonediazide ester compounds are particularly preferred.

As the O-quinonediazide compound used in the present invention, each of the above compounds may be used alone, or two or more thereof may be used in combination.

The proportion of the 0-quinonediazide compound used in the present invention in the photosensitive composition is preferably 5 to 80% by weight,
Particularly preferably, it is 10 to 50% by weight.

The photosensitive composition of the present invention can contain a known alkali-soluble resin. Examples of alkali-soluble resins include novolac resins, such as phenol-formaldehyde resins, cresol-formaldehyde resins, phenol-modified xylene resins, and polyhydroxystyrene, but such alkali-soluble polymer compounds account for 40% by weight of the total composition. It is used in the following amounts.

In addition to the materials described above, the photosensitive composition of the present invention can contain other additives as necessary. Plasticizers include various low-molecular compounds such as phthalate esters, triphenyl phosphates, maleate esters, and coating properties improvers include surfactants such as fluorine surfactants and ethyl cellulose polyalkylene ether. Examples include nonionic activators and the like, as well as printout materials for forming visible images upon exposure to light. The printout material consists of a compound that generates acid or free radicals when exposed to light, and an organic dye that changes its color tone by interacting with it. 0-naphthoquinonediazide 4-sulfonic acid halide described in JP-A-50-36209, JP-A-53
-Trihalomethyl described in Publication No. 36223-
2-pyrone and trihalomethyl-triazine, JP-A-55
An ester compound of 0-naphthoquinonediazide-4-sulfonic acid chloride and a phenol or aniline having an electron-withdrawing substituent, which is described in Japanese Patent Application Laid-Open No. 55-77742. Examples include halomethyl-vinyl-oxadiazole compounds and diazonium salts.

Among these, halomethyl-vinyl-oxadiazole compounds are preferable, and in particular, halomethyl-vinyl-oxadiazole compounds are preferable, and in particular, the compounds described in JP-A No. 60-138539, which are formed by directly or via a vinyl group, are A 2-halomethyl-1,3,4-oxadiazole compound having the 5-position is more preferred.

Further, as the organic dye, for example, Victoria Pure Blue BOH [Hodogaya Chemical Co., Ltd.], Oil Blue #6
03 [Orient Chemical], Patent Pure Blue [
Made by Sumitomo Mikuni Chemical], crystal violet, brilliant green, ethyl violet, methyl green,
Triphenylmethane type, diphenylmethane type represented by erythrosin B1 basic tsuksin, malachite green, oil red, m-cresol purple, rhodamine B1 auramine, 4-p-diethylaminophenylimino naphthoquinone, cyano-p-diethylaminophenyl acetanilide, etc. Examples include oxazine-based, xanthine-based, iminonaphthoquinone-based, azomethine-based, and anthraquinone-based dyes. Among these, triphenylmethane dyes are preferred.

Further, a sensitizer for improving sensitivity can also be added to the photosensitive composition of the present invention. As the sensitizer, gallic acid derivatives described in JP-A No. 57-118237, 5-membered cyclic acid anhydrides such as those described in JP-A-52-80022, such as phthalic anhydride; , tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, anhydride co! Examples include monolic acid, pyrometic acid, itaconic acid, etc., and 6-membered cyclic acid anhydrides such as those described in JP-A-58-11932, such as glutaric anhydride and its derivatives. Of these,
Cyclic acid anhydrides are preferred, and 6-membered cyclic acid anhydrides are particularly preferred.

A positive-working photosensitive lithographic printing plate can be formed by dissolving the photosensitive composition of the present invention in a solvent that dissolves each of the above-mentioned components, and applying and drying the solution on the surface of a suitable support. Examples of solvents that can be used include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate, dimethyl formamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, and methyl ethyl ketone. These solvents may be used alone or in combination of two or more.

As the coating method, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, and curtain coating can be used.

Supports on which the photosensitive layer is provided using the photosensitive composition of the present invention include metal plates such as aluminum, zinc, copper, steel, etc., and metal plates plated or vapor-deposited with chromium, zinc, copper, nickel, aluminum, iron, etc. Examples include metal plates, paper, plastic films, paper coated with resin, paper covered with metal foil such as aluminum, and plastic films treated to make them hydrophilic. Among these, aluminum plates are preferred.

When an aluminum plate is used as a support, it is preferably subjected to surface treatments such as graining, anodizing, and, if necessary, sealing. Known methods can be applied to these treatments.

Examples of the graining treatment include a mechanical method and an electrolytic etching method. Examples of the mechanical method include a ball polishing method, a brush polishing method, a polishing method using liquid honing, and a buffing method.

``Depending on the composition of the aluminum material, the various methods described above can be used alone or in combination.The electrolytic etching method is preferred.

Electrolytic etching is carried out in a bath containing one or a mixture of two or more inorganic acids such as phosphoric acid, sulfuric acid, hydrochloric acid, and nitric acid. After the graining treatment, if necessary, desmut treatment is performed with an aqueous alkali or acid solution, neutralized, and washed with water.

The anodic oxidation treatment is performed by electrolyzing using an aluminum plate as an anode using a solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc. as an electrolytic solution. The amount of the anodic oxide film formed is suitably 1 to 50 .mu./dd, preferably 10 to 40 .mu./dd. The amount of anodized film can be determined by, for example, coating an aluminum plate with a phosphoric acid chromic acid solution (85% phosphoric acid solution: !35ml1 chromium oxide (V
I): Prepared by dissolving 20sr in 1g of water),
It is determined by dissolving the oxide film and measuring the weight change of the plate before and after the film is dissolved.

Specific examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition, the aluminum plate support may be subjected to subbing treatment with an aqueous solution of a water-soluble polymer compound or a metal salt such as fluorinated zirconate.

In addition, in general, when contact baking a film original onto a photosensitive lithographic printing plate, the printing frame is vacuumed, and a method for improving this vacuum adhesion is also a positive-working photosensitive lithographic printing plate using the photosensitive composition of the present invention. Can be applied to printing plates. Methods for improving vacuum adhesion include mechanically creating unevenness on the surface of the photosensitive layer, scattering solid powder on the surface of the photosensitive layer,
A method of providing a matte layer on the surface of a photosensitive layer as described in JP-A-50-125805, and JP-A-50-125805.
Examples include a method of heat-sealing a solid powder onto the surface of a photosensitive layer, as described in Japanese Patent No. 5-12974.

A positive-working photosensitive lithographic printing plate to which the photosensitive composition of the present invention is applied can be used in the same manner as those conventionally used. For example, an ultra-high pressure mercury lamp is passed through a transparent film,
It is exposed to light using a light source such as a metal halide lamp, a xenon lamp, or a tungsten lamp, and then developed with an alkaline developer, leaving only the unexposed portions on the surface of the support, creating a positive relief image.

Examples of alkaline developers include sodium hydroxide,
Examples include aqueous solutions of alkali metal salts such as potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, sodium diphosphate, and sodium triphosphate.

The concentration of the alkali metal salt is preferably 0.1 to 10% by weight. In addition, an anionic surfactant, if necessary, is added to the developer.
Amphoteric surfactants and organic solvents such as alcohols can be added.

[Examples] The present invention will be explained below using Examples, but the present invention is not limited thereto.

Example 1 An aluminum plate with a thickness of 0.24 m+s was heated in a 5% aqueous sodium hydroxide solution at a temperature of 25°C and a current density of 80 A/d.
Electrolytic etching treatment was performed under the conditions of r&, treatment time: 30 seconds. Next, a desmut treatment was performed with a 5% aqueous sodium hydroxide solution, and then an anodization treatment was performed in a sulfuric acid solution. When the amount of anodic oxide film was measured by the method described above, it was found to be 201 g/drrf.

Next, it was immersed in a hot aqueous solution at 90°C for pore sealing treatment.

Subsequently, a photosensitive coating solution having the composition shown below was coated on the aluminum support using a spin coater and dried at 100° C. for 4 minutes to obtain a photosensitive lithographic printing plate (Sample 1). The coating weight after drying was approximately 24 .mu./drrr.

[Photosensitive coating liquid]

2.3. Ester compound of 4-trihydroxybenzophenone and naphthoquinone-(1,2)-diazide-(2)-5-sulfonic acid chloride 3.6g Following binder resin (a) 7.4g Victoria Pure Blue B OH0 ,084g-2-Trichloromethyl-5-[β(2-benzofuryl)vinyl] 1.3.4-oxadiazole O,1213g methyl cellosolve 100ml Binder resin (a) p-hydroxyaniline 400g, hydroquinone monomethyl ether 4g 1 acetone 4g and pyridine 36
0g, cooled from the outside using a cryogen, and the internal temperature was -
1 (When the temperature drops to 1℃, methacrylic acid chloride 42
0 g was added dropwise while stirring. The dropping rate was adjusted so that the reaction temperature was 0°C or lower, and after the dropwise addition was completed, the mixture was stirred at 0 to 3°C for 2 hours.

Then, after stirring at 25°C for 2 hours, the reaction solution was concentrated to 1x3, poured into 10 g of dilute hydrochloric acid (pH about 1.0), and the resulting precipitate was suction-filtered to obtain a white solid. Ta. This white solid was dissolved in warm methanol 2I,
Furthermore, add 5% sodium carbonate aqueous solution 21 and raise the temperature to 40°C.
The mixture was stirred for 30 minutes. This dark red solution was then diluted with 5%
The mixture was poured into 8 g of an aqueous hydrochloric acid solution to form a large amount of precipitate, which was filtered with suction and dried to obtain a pale pink solid.

This was recrystallized from a mixed solvent of ethanol and water to produce N-(4-hydroxyphenyl) with a melting point of 155-156°C.
450 g of colorless needle-like crystals of methacrylamide were obtained.

Obtained N-(4-hydroxyphenyl) methacrylamide 10B, 4. , methyl methacrylate 23.9g
and vinylpyrrolidone 5G,5. was dissolved in 200 ml of methyl cellosolve, replaced with nitrogen gas, and heated to 80°C.
The mixture was heated for 4 hours to obtain a polymer solution.

This polymer solution was poured into 3fI of 5% hydrochloric acid, and the resulting white precipitate was collected by filtration and dried to yield 1144.6 g of binder resin (a) [polymer example (a) of the present invention].

(Weight average molecular weight Mw -1,2XIO') In Sample 1, the following binder resins (b), (e) and (d) were used in place of binder resin (a), and the rest
Samples 2.3 and 4 were obtained in exactly the same manner as above.

Binder resin (b) N-(4-hydroxyphenyl) methacrylamide 79
．． 8. , methyl methacrylate-1-54.8g, vinyl chloroacetate 18.1g and vinylpyrrolidone 58.9g
165 g of binder resin (b) [polymer example (c) of the present invention] was obtained in the same manner as binder resin (a).

(Weight average molecular weight Mw -3,5x 10') Binder resin (c) N-(4-hydroxyphenyl) methacrylamide 53
．． 2g, methyl methacrylate 45.1g, vinyl p-cyanobenzoate 51.9g, methacrylic acid 19.4g
1,151 g of binder resin (C) [polymer example (nu) of the present invention] was prepared in the same manner as binder resin (a) using 25 g of vinylpyrrolidone and 25 g of vinylpyrrolidone.

(Weight average molecular weight Mw-s, 4x 10') Binder resin (d) N-(4-hydroxyphenyl)acrylamide 106
．． 4 g of acrylonitrile, 82 g of acrylonitrile, 73.2 g of methyl methacrylate and 8.58 g of α,α'-azobisisobutyronitrile in acetone/methanol (1:1).
After dissolving in 800ml of mixed solvent and replacing with nitrogen gas,
The mixture was heated at 80° C. for 4 hours to obtain a polymer solution.

This polymer solution was poured into 3 g of 5% hydrochloric acid, and the resulting white precipitate was collected by filtration and dried to obtain 195 g of binder resin (d) (comparative polymer).

(Weight average molecular weight M w -3.5x 10') Step tablets for sensitivity measurement (NQ, manufactured by Eastman Kodak Company,
2. Gray scale in 21 steps with 0.15 densitometer)
and a 2kV metal halide lamp (manufactured by Iwasaki Electric Co., Ltd.) with a positive original film (idle fin 2000)
8. as a light source. (Exposure for 70 seconds under the conditions of IwW/c-, then develop for 45 seconds at 25°C using a 6-fold dilution of the positive PS plate developer "5DR-1" (manufactured by Konica Corporation). As a result, a lithographic printing plate in which the non-image areas were completely removed was obtained.

Sensitivity was evaluated by determining which stage of the above-mentioned gray scale having a density difference of 0.15.21 stages was completely developed (became clear).

In order to examine resistance to processing chemicals, durability against plate cleaner and washing oil, which are used as cleaning liquid to remove background stains that occur in non-image areas during printing, was investigated. The printing plate, on which an image with density differences on the above gray scale stages was formed, was immersed in stock solutions of FD plate cleaner (manufactured by Toyo Ink Co., Ltd.) and UV plate cleaner (manufactured by Morohoshi Ink Co., Ltd.) for 12 hours at room temperature, and in the same manner. The image area was immersed in the UV plate cleaning solution Best Cure (manufactured by Toka Shiki Kagaku) and the UV plate cleaning liquid Tsurfit (manufactured by Clarei Sobrene Chemical Co., Ltd.) for 10 minutes, washed with water, and compared with the image area before immersion. The degree of erosion against treatment chemicals was measured.

In addition, in order to examine ink receptivity, the number of waste sheets at the start of printing was measured. Plate Washinigum liquid 5G was applied to the lithographic printing plate obtained by exposing and developing the positive original film.
After applying W-1 (manufactured by Konica Corporation) with a sponge and drying it, apply it to a sheet-fed printing machine (Hamadustar 900CDI).
) to determine the gum removability immediately after printing started.

The results of sensitivity, processing chemical resistance, and ink receptivity are shown in Table 1.

Table 1 In Table 1, A: Slight erosion in the image area.

B: Erosion as above was observed, and the grains of the support under the photosensitive layer were slightly exposed.

C: Significant erosion was observed as above, and the grains of the support under the photosensitive layer were completely exposed.

It means that.

In addition, ink receptivity is judged by the number of pieces of waste paper required from the start of printing until the gum is completely removed, the ink is sufficiently attached to the image area, and a complete print is obtained. Ta. The smaller the number, the better the gum removability and the better the ink receptivity.

From the results in Table 1, samples 1 to 3 of the present invention, in which the binder resin is a polymer having a structural unit represented by general formula [I] and a structural unit derived from vinylpyrrolidone, are different from binder resin (d) (comparison). It can be seen that the resistance to the plate cleaner used when UV ink is used is better than that using UV ink. Furthermore, the sensitivity and ink receptivity were the same as those using binder resin (d), and there was no deterioration.

[Effects of the invention] The photosensitive composition of the present invention has excellent resistance to processing chemicals, and the lithographic printing plate using the photosensitive composition of the present invention can withstand processing chemicals used in UV ink printing and has high printing durability. increase Also,
The photosensitive composition of the present invention has sufficient sensitivity and excellent ink receptivity.

Applicant Co., Ltd. Agent Yoshio Iwama

Claims (2)

[Claims] (1) As a binder, at least (a) the following general formula [
A photosensitive composition characterized by using a polymer having a structural unit represented by [I] and (b) a structural unit derived from vinylpyrrolidone. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. Represents a halogen atom, alkyl group or aryl group, R_4 represents a hydrogen atom, alkyl group, aryl group or aralkyl group. Y represents an aromatic group. X represents a divalent organic group, n is 0 to 5 represents an integer.) (2) The polymer further has the following general formula [II], general formula [III]
The photosensitive composition according to claim 1, wherein the photosensitive composition is a polymer having at least one structural unit selected from the structural units represented by the general formula [IV]. General formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_5 represents a hydrogen atom, halogen atom, alkyl group, or aryl group, R_6 represents an alkylene group or arylene group, and ) General formula [III] ▲ Numerical formulas, chemical formulas, tables, etc. X_2 represents an electron-withdrawing group.) General formula [IV] ▲Mathematical formula, chemical formula, table, etc.▼ (In the formula, R_9 represents a hydrogen atom, a halogen atom, an alkyl group, or an aryl group, and (Represents a group.)