JP2742837B2 - Photosensitive lithographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate, and more particularly to a photosensitive lithographic printing plate provided with a photosensitive layer containing a photocrosslinkable polymer which is crosslinked by a cycloaddition reaction.

[0002]

2. Description of the Related Art Photocrosslinkable materials which are crosslinked by a cycloaddition reaction are well known, and they are widely used as main components of photosensitive compositions used for producing photosensitive lithographic printing plates and the like. As such a photocrosslinkable polymer,
A polymer having a maleimide group in a side chain, a cinnamyl group having a photodimerizable unsaturated double bond adjacent to an aromatic nucleus, a cinnamoyl group, a cinnamylidene group, a cinnamylidene acetyl group or a chalcone group in a side chain or a main chain. These polymers are useful and some have been put to practical use. In particular, polymers having a maleimide group in the side chain and polyester resins having a cinnamic acid skeleton in the molecular chain produced by condensation of phenylenediacrylic acid or its alkyl ester with glycol have relatively high sensitivity. .

On the other hand, since the photosensitive layer containing the photo-crosslinkable polymer does not have a property of discoloring upon exposure (printing out property), it has been desired to provide a visually distinguishable performance. Many baked-out compositions are known [for example, "Light-Sensitiv" by J. KOSAR.
e Systems, J. Wily and Sons "(New York 1965) pp3
85-401], and combinations of various compounds are known in the fields of photosensitive lithographic printing plates, photoresists and the like (for example, Japanese Patent Publication No. 40-2203, Japanese Patent Application Laid-Open No.
No. 8128, JP-A-54-74728 and U.S. Pat. No. 4,139,390). Among such bakeout compositions, combinations of organic polyhalogen compounds or photooxidants with various leuco dyes are known as being particularly effective (for example, Photogr. Sci. Eng., 5 , 98).
-103, 1961 and U.S. Patent No. 3,042,515).

[0004] However, when the print-out property is imparted by a leuco dye, a large amount of leuco dye is added or separately added to facilitate plate inspection for distinguishing an image area from a non-image area after development. It is necessary to add a coloring agent. As described above, it is not preferable to include a large amount of an additive such as a photooxidant, a leuco dye, and a coloring agent in the photosensitive layer because the inherent properties of the photosensitive layer, for example, sensitivity and printing durability are reduced. .

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photosensitive layer containing a photocrosslinkable polymer which has excellent sensitivity and performance while improving the above-mentioned drawbacks and having good printability. Another object of the present invention is to provide a photosensitive lithographic printing plate which gives a printing plate having excellent printing performance.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that the use of a compound capable of generating a strong acid by a specific light and a dye capable of fading or discoloring by an acid is used. Have been achieved, leading to the present invention. That is, the present invention relates to a photosensitive lithographic printing plate provided with a photosensitive layer containing a photocrosslinkable polymer having a photodimerizable unsaturated bond, in the photosensitive layer, a compound which generates a strong acid upon exposure to light, or is subjected to acid fading or Disclosed is a photosensitive lithographic printing plate characterized by containing a discoloring dye (excluding a leuco dye) .

Hereinafter, the present invention will be described in detail. The photocrosslinkable polymer having an unsaturated bond capable of photodimerization used in the present invention has a maleimide group, a cinnamyl group, a cinnamoyl group, a cinnamylidene group, a cinnamylideneacetyl group, a chalcone group, or the like in a side chain or a main chain. Polymers.

As a polymer having a maleimide group in the side chain, Japanese Patent Application Laid-Open No. 52-988 (corresponding to US Pat. No. 4,079,041)
Gazette, German Patent No. 2,626,769, European Patent No. 21,019, European Patent No. 3,552, and Die Angewandte Makromolekulare Chemie 1
15 (1983), pages 163 to 181:

[0009]

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Wherein R ¹ and R ² each independently represent an alkyl group having up to 4 carbon atoms, or R ¹ and R ² together form a 5- or 6-membered carbon Or a polymer having a maleimide group in the side chain represented by the following formula:
No. -12992, No. 49-128993, No.50-5379, No.5
Nos. 0-5377, 50-5379, 50-5378, 50
No.-5380, No.53-5298, No.53-5299, No.53-
No. 5300, No. 50-50107, No. 51-47940, No. 52
Nos. -13907, 50-45076, 52-121700, 50-10884, 50-45087, German Patent 2,34
Nos. 9,948 and 2,616,276 each of the following general formula (II):

[0011]

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(Wherein, R ³ represents an aromatic group, and R ⁴ represents a hydrogen atom, a halogen atom, an alkyl group or a cyano group). . The average molecular weight of these polymers is 1000 or more, preferably 20,000 to 300,000. Further, these polymers have an average of two or more maleimide groups per molecule in the side chain.

In order to make these polymers having a maleimide group in the side chain soluble or swellable in alkaline water, they can be achieved by including an acid group in the polymer.
Specific examples of the acid group include a carboxylic acid, a sulfonic acid, a phosphoric acid, a phosphonic acid, an alkali metal salt or an ammonium salt thereof, and a pKa that is dissociated with alkaline water.
In the acid group _include, -SO 2 NHCO _-, - CON
HCO -, - SO ₂ NHCOO-, and a 4-hydroxyphenyl group. These monomers having an acid group and a monomer having a maleimide group are, for example, 10 /
90-50 / 50, preferably 20 / 80-40 / 6
The polymer of the present invention can be easily obtained by copolymerizing at a ratio of 0 (molar ratio). The acid value of the maleimide polymer having an acid group is preferably in the range of 30 to 300, and more preferably 50 to 250. Preferred examples of the copolymerizable monomer having an acid group include vinyl monomers having a carboxyl group such as acrylic acid and methacrylic acid, maleic anhydride, and itaconic anhydride.

[0014] Among these polymers having an acid value,
Dee Angebandute Macromolecule Kemi
ー (Die Angewandte Makromolekulare Chemie)128
(1984), pages 71-91.
N- [2-methacryloyloxy) ethyl] -2,3
-Dimethyl maleimide and methacrylic acid or acrylic
Copolymers with acids are useful. Further synthesis of this copolymer
When copolymerizing the third component vinyl monomer
Therefore, it is easy to synthesize a multi-component copolymer according to the purpose.
Can be. For example, as a vinyl monomer of the third component,
Alkyl whose homopolymer has a glass transition point below room temperature
Using methacrylates and alkyl acrylates
Therefore, flexibility can be given to the copolymer.

Among the other photocrosslinkable polymers of the present invention having a cinnamyl group, a cinnamoyl group, a cinnamylidene group, a cinnamylidene acetyl group, a chalcone group or the like in the side chain or the main chain, a photosensitive cinnamoylene group is used in the main chain. For example, U.S. Pat.No. 3,030,208, U.S. Pat.
There are photosensitive polyesters described in JP-A Nos. 96 and 828455. The above polyester is a suitable polycarboxylic acid,
Alternatively, it is prepared by condensing an appropriate lower alkyl ester of a polycarboxylic acid or chloride with an appropriate polyhydric alcohol in the presence of an esterification catalyst.

The following are examples of the solubilized alkaline water of these polymers. That is, an unsaturated double bond capable of photodimerization adjacent to an aromatic nucleus in a main chain as described in JP-A-60-191244,
Polyester prepolymers having a carboxyl group at the side chain and a hydroxyl group at the terminal have a chain extender having two or more functional groups capable of reacting with hydroxyl groups in the molecule, such as diisocyanate compounds, diphenyl terephthalate, diphenyl carbonate and terephthaloyl bis (N -Caprolactam) or a polyester prepolymer or a polyurethane prepolymer having a photodimerizable unsaturated double bond adjacent to an aromatic nucleus in the main chain and a hydroxyl group at a terminal in the main chain. Examples of the extender include a photosensitive polymer obtained by reacting pyromellitic dianhydride or cyclopentanetetracarboxylic dianhydride to introduce a carboxyl group into a side chain.

Further, a functional group capable of photodimerization is provided on a side chain,
Examples thereof include an alkali water-soluble or swellable photosensitive polymer having an acid value of 20 to 200 and having a carboxyl group in a side chain. These photosensitive polymers are disclosed in
No. 175729, JP-A-62-175730, JP-A-63-25443
And JP-A-63-218944 and JP-A-63-218945.

The photocrosslinkable polymer used in the present invention has a molecular weight of 1,000 or more, preferably 10,000 to 50.
It is desirable to use a material having a size of 20,000, particularly preferably 20,000 to 300,000. The amount of the photocrosslinkable polymer to be added to the entire photosensitive layer composition is 10 to 99% by weight, preferably 50 to 99% by weight.
% By weight.

In the present invention, it is desirable to use a sensitizer in the photosensitive layer. As such a sensitizer,
A photosensitizing polymer capable of sensitizing the above photocrosslinkable polymer,
It is preferable to use a triplet sensitizer having a maximum absorption in the range of 0 nm or more. Specific examples include benzophenone derivatives, benzuanthrone derivatives, quinones, aromatic nitro compounds, naphthothiazoline derivatives, benzothiazoline derivatives, thioxanthones, naphthothiazole derivatives, ketocoumarin compounds, benzothiazole derivatives, naphthofuranone compounds, pyrylium salts, thiapyrylium salts, and the like. Can be mentioned. Specifically, Michler Kane, N,
N'-diethylaminobenzophenone, benzuanthrone, (3-methyl-1,3-diaza-1,9-benzo)
Anthrone picramide, 5-nitroacenaphthene, 2-
Chlorothioxanthone, 2-isopropylthioxanthone, dimethylthioxanthone, methylthioxanthone
1-ethylcarboxylate, 2-nitrofluorene,
2-dibenzoylmethylene-3-methylnaphthothiazoline, 3,3-carbonyl-bis (7-diethylaminocoumarin), 2,4,6-triphenylthiapyrylium perchlorate, 2- (P-chlorobenzoyl) naphthothio Other than azole, JP-B-45-8832, JP-A-52-1297
No. 91, JP-A-62-294238, JP-A-2-173646, JP-A-2-131236, EP 368327, JP-A-2-2365
No. 52 and Japanese Patent Application No. 1-190963 are sensitizers. These sensitizers are added in an amount of about 1 to 20% by weight, more preferably 3 to 1% by weight of the photosensitive layer.
0% by weight.

In the present invention, the dyes that fade or discolor by the acid used include diphenylmethane, triphenylmethane, thiazine, oxazine, xanthine, anthraquinone, iminonaphthoquinone, and the like.
Azomethine-based and azo-based dyes are effectively used.
Examples of these are as follows. Brilliant Green, Eosin, Ethyl Violet, Erythrosin B, Methyl Green, Crystal Violet, Basic Fuchsin, Phenolphthalene, 1,3-Diphenyltriazine, Alizarin Red S, Thymolphthalein, Methyl Violet 2B, Quinaldin Red, Rose Bengal, Methanil yellow, thymol sulfophthalein, xylenol blue, methyl orange,
Orange IV, diphenylthiocarbazone, 2,7-dichlorofluorescein, paramethyl red, Congo red, benzopurpurine 4B, α-naphthyl red, Nile blue 2B, Nile blue A, phenacetaline, methyl violet, malachite green, parafuchsin,
Oil Blue # 603 [Orient Chemical Industry Co., Ltd.
Oil Pink # 312 (manufactured by Orient Chemical Industry Co., Ltd.), Oil Red 5B (manufactured by Orient Chemical Industry Co., Ltd.), Oil Scarlet # 308 (manufactured by Orient Chemical Industry Co., Ltd.), Oil Red OG (Orient Chemical Co., Ltd.) Industrial Co., Ltd.), Oil Red RR (Orient Chemical Co., Ltd.), Oil Green # 502 (Orient Chemical Co., Ltd.), Spiron Red BEH Special (Hodogaya Chemical Co., Ltd.), Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Industry Co., Ltd.], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, fast acid violet R, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2- Carboxanilino-4-
p-diethylaminophenyliminonaphthoquinone, 2-
Carbostearylamino-4-p-dihydrooxyethyl-amino-phenyliminonaphthoquinone, p-methoxybenzoyl-p'-diethylamino-o'-methylphenyliminoacetanilide, cyano-p-diethylaminophenyliminoacetanilide, 1-phenyl-3
-Methyl-4-p-diethylaminophenylimino-5
-Pyrazolone, 1-β-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone, methyl yellow, p-diethylaminoazobenzene, 2,4-dinitro-5-chloro-2'-acetoamino-4'-diethylamino-5 '-Methoxyazobenzene.

These may be used in combination of two or more.
The ratio between the dye and the compound that generates a strong acid upon exposure is from about 0.01 part by weight to about 100 parts by weight of the compound that generates a strong acid per 1 part by weight of the dye, more preferably,
It is in the range of 0.1 to 10 parts by weight, most preferably 0.5 to 5 parts by weight. Compounds that generate a strong acid upon exposure used in the photosensitive layer of the present invention include, for example, diazonium salts, sulfonium salts, iodonium salts, allene iron complex compounds, and the like. Acid, tetrafluoroboric acid, arsenic hexafluoride,
Strong acids such as antimony hexafluoride and trifluoromethanesulfonic acid are suitable. Specifically, 4-diazodiphenylamine hexafluorophosphate, 3-methoxy-4-diazodiphenylamine hexafluorophosphate, 4-diazodiphenylamine tetrafluoroborate, 4-diazo-2 −
Methoxydiphenyl sulfide hexafluorophosphate, 4
-Diazo-2,5-diethoxydiphenyl sulfide
Hexafluorophosphate, 4-diazo-2-methoxy-4'-
Dodecyl diphenyl sulfide hexafluorophosphate,
Zoic diazo N020 (CI. 37175)
Phosphate, azoic diazo N024 (CI.3)
7155) · hexafluorophosphate, triphenylsulfonium hexafluorophosphate arsenic salts, Application Benefits triphenylsulfonium trifluoromethanesulfonate, diphenyl ethyl sulfonium tetrafluoroborate, triphenyl sulfonium hexafluorophosphate, diphenyl Examples thereof include iodonium hexafluorophosphate, (1-6-7-cumene) (7-cyclopentadienyl) iron) (1+) hexafluorophosphoric acid (1-).

In addition, it is preferable to use a compound such as an organic halogen compound or orthoquinonediazidosulfonyl chloride in combination. The photosensitive layer of the present invention can contain a binder if necessary, and is usually selected appropriately from linear organic polymers. Specific examples of the binder include chlorinated polyethylene, chlorinated polypropylene, polyacrylate alkyl ester, acrylate alkyl ester, acrylonitrile, vinyl chloride, styrene, a copolymer with at least one kind of monomer such as butadiene, polyamide, Examples include methylcellulose, polyvinyl formal, polyvinyl butyral, methacrylic acid copolymer, acrylic acid copolymer, and itaconic acid copolymer. Further, if necessary, another dye pigment or the like can be contained in addition to the dye which is discolored by the acid.

Further, the photosensitive layer of the present invention may contain a plasticizer. As such a plasticizer, a dialkyl phthalate such as dibutyl phthalate or dihexyl phthalate, an oligoethylene glycol alkyl ester, or a phosphate plasticizer may be used.
In addition, it is also preferable to use a negative working diazo resin in the photosensitive layer. These diazo resins function as an adhesive for a support having a hydrophilic surface or as a crosslinking agent.

Examples of such a diazo resin include 4-diazo-diphenylamine, 1-diazo-4-N, N-dimethylaminobenzene, 1-diazo-4-N, N-diethylaminobenzene, 1-diazo-4-N -Ethyl-N-hydroxyethylaminobenzene, 1-diazo-4-N-
Methyl-N-hydroxyethylaminobenzene, 1-diazo-2,5-diethoxy-4-benzoylaminobenzene, 1-diazo-4-N-benzylaminobenzene,
1-diazo-4-N, N-dimethylaminobenzene, 1
-Diazo-4-morpholinobenzene, 1-diazo-
2,5-dimethoxy-4-p-trimercaptobenzene, 1-diazo-2-ethoxy-4-N, N-dimethylaminobenzene, p-diazo-dimethylaniline, 1-
Diazo-2,5-dibutoxy-4-morpholinobenzene, 1-diazo-2,5-diethoxy-4-morpholinobenzene, 1-diazo-2,5-dimethoxy-4-morpholinobenzene, 1-diazo- 2,5-diethoxy-4-morpholinobenzene, 1-diazo-2,5-diethoxy-4-p-trimercaptobenzene, 1-diazo-3-ethoxy-4-N-methyl-N-benzylaminobenzene, 1-diazo-3-chloro-4-N, N-diethylaminobenzene, 1-diazo-3-methyl-4-
Pyrrolidinobenzene, 1-diazo-2-chloro-4-
N, N-dimethylamino-5-methoxybenzene, 1-
Diazo-3-methoxy-4-pyrrolidinobenzene, 3-
Diazo monomers such as methoxy-4-diazodiphenylamine, 3-ethoxy-4-diazodiphenylamine, 3- (n-propoxy) -4-diazodiphenylamine, 3-isopropoxy-4-diazodiphenylamine, formaldehyde, acetaldehyde, propion Aldehyde, butylacetaldehyde, isobutyraldehyde, benzaldehyde or a condensing agent such as glyoxylic acid, aldehyde having a carboxyl group such as malonaldehyde acid, etc. in a molar ratio of 1:10 to 1: 0.05, respectively.
Preferably, a reaction product of an anion and a condensate obtained by condensing in a usual manner in an acidic medium at a ratio of 1: 2/1: 0.2 is used. Examples of such anions include tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitroortho-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4 , 6-Trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfonic acid, 2 −
Mention may be made of anions such as methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid and paratoluenesulfonic acid. Among them, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid and 2,5-
Anions of alkyl aromatic sulfonic acids, such as dimethylbenzene sulfonic acid, are preferred.

Further, a diazo resin having a carboxyl group or a hydroxy group is preferable for solubilization in an alkaline developer. Such a diazo resin can be obtained by co-condensing an aromatic compound having at least one carboxyl group with the above diazo monomer compound. Specific examples of the aromatic compound having a carboxyl group or a hydroxy group include salicylic acid, alkyl group-substituted salicylic acid, benzoic acid, hydroxybenzoic acid, gallic acid, hydroxyphthalic acid, phenylacetic acid, hydroxyphenylacetic acid, phenoxyacetic acid, and Compounds obtained by substituting these compounds with alkyl, alkoxy, carboxy, and the like. In addition, the diazo compounds described in JP-B-49-48001 are also suitable.

A co-condensed diazo resin containing, as constituent units, an aromatic compound having at least one carboxyl group or a hydroxy group and an aromatic diazonium compound can be prepared by a known method, for example, photographic science.
And Engineering (Photo. Sci., Eng.) No. 17
Vol. 33, p. 1973, U.S. Pat. No. 2,063,631,
According to the method described in the specification of each of the same 2,679,498, sulfuric acid, phosphoric acid, an aromatic diazonium compound in hydrochloric acid, an aromatic compound having a carboxyl group, and aldehydes,
For example, it can be obtained by polycondensing paraformaldehyde, acetaldehyde, benzaldehyde or ketones such as acetone and acetophenone.

The aromatic compound having a carboxyl group or a hydroxy group in the molecule, the aromatic diazonium compound and the aldehydes or ketones can be freely combined with each other. Is also possible. Furthermore, cocondensable phenols having no carboxyl group hydroxy group can be added for cocondensation.

At this time, the charged molar ratio of the aromatic compound having a carboxyl group to the aromatic diazonium compound is as follows:
1: 0.1-0.1: 1, preferably 1: 0.2-0.2-1,
More preferably, the ratio is 1: 0.5 to 0.2: 1. Further, in this case, the molar ratio of the total of the aromatic compound having a carboxyl group or a hydroxy group and the aromatic diazonium compound to the aldehydes or ketones is usually 1: 0.6 to 1.6.
2, preferably at a ratio of 0.7 to 1.5 and reacting at a low temperature for a short time, for example, about 3 hours, to obtain a co-condensed diazo resin.

In addition, diazo resins described in JP-A-3-2868, and Japanese Patent Application No. 2-37785,
A diazo resin having sulfonic acid or phosphoric acid in the molecule described in Japanese Patent Application No. 2-130856 is also preferable. The addition amount of these diazo resins to the entire photosensitive layer composition is 0.1 to 0.1.
15% by weight is preferred, more preferably 0.3-5% by weight
It is.

The above-mentioned photosensitive layer is prepared by adding a photosensitive composition comprising the above-mentioned components to, for example, 2-methoxyethanol, 2-methoxyethyl acetate, methyl cellosolve, propylene glycol monomethyl ether, 3-methoxypropanol, 3-methoxypropyl. Acetate, acetone,
Methyl ethyl ketone, ethylene dichloride, methyl lactate, ethyl lactate, methanol, dimethylformamide,
It is formed by dissolving in a suitable solvent such as ethanol or methyl cellosolve acetate alone or in a mixed solvent in which these are appropriately combined, and coating the solution on a support. The coating amount in the range of about 0.1 g / m ² ~ about 10 g / m ² in weight after drying are suitable, preferably from 0.5 to 5 g / m ^2.

The surface of the photosensitive layer of the present invention may be subjected to a matting process in order to further enhance the adhesion to the film.
These are described in JP-A-55-12974 and JP-A-58-12974.
Compounds and methods described in -182636 can be used. The support having a hydrophilic surface used in the present invention is preferably a dimensionally stable plate. Such dimensionally stable plate-like materials include those conventionally used as supports for printed matter, and they can be suitably used in the present invention. Examples of such a support include paper, paper laminated with plastics (eg, polyethylene, polypropylene, polystyrene, etc.),
Metal plates such as aluminum (including aluminum alloys), zinc, copper, etc., cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose acetate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, Examples include plastic films such as polycarbonate and polyvinyl acetal, and paper or plastic films on which the above-mentioned metals are laminated or vapor-deposited. Among these supports, the aluminum plate is preferable because it is extremely stable in dimension, is inexpensive, and has particularly good adhesion to the photosensitive layer of the present invention. Further, a composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in JP-B-48-18327 is also preferable.

In the case of a metal, particularly an aluminum support, it is preferable that a surface treatment such as graining treatment or anodic oxidation treatment is performed. Further, in order to enhance the hydrophilicity of the surface, it is preferable to perform a dipping treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like. As described in U.S. Pat. No. 2,714,066, an aluminum plate grained and then immersed in an aqueous solution of sodium silicate, and an anodized aluminum plate as described in JP-B-47-5125. After immersion, an immersion treatment in an aqueous solution of an alkali metal silicate is also preferably used.

Also, silicate electrodeposition as described in US Pat. No. 3,658,662 is effective. Also, a surface obtained by combining the electrolytic grain disclosed in JP-B-46-27481, JP-A-52-58602, and JP-A-52-30503 with the above anodic oxidation treatment and sodium silicate treatment. Processing is also useful.

It is also preferable to sequentially perform brush grain, electrolytic grain, anodic oxidation treatment, and sodium silicate treatment as disclosed in JP-A-56-28893. Further, after these treatments are performed, a water-soluble resin such as polyvinylphosphonic acid, a polymer or a copolymer having a sulfonic acid group in a side chain, or a primer coated with polyacrylic acid is also preferable.

These hydrophilic treatments are performed not only to make the surface of the support hydrophilic, but also to prevent harmful reaction with the photosensitive composition provided thereon, This is performed to improve the adhesion. As a developer for the photosensitive composition of the present invention, sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium phosphate tribasic, sodium phosphate dibasic, ammonium phosphate tribasic, An inorganic alkaline agent such as ammonium diphosphate, sodium metasilicate, sodium bicarbonate, aqueous ammonia, or an aqueous solution of an organic amine compound such as monoethanolamine or triethanolamine is suitable, and their concentration is 0.1. -10% by weight, preferably 0.5-5% by weight.

Further, an organic solvent such as a surfactant or alcohol can be added to the alkaline aqueous solution, if necessary. Preferred examples of the organic solvent include benzyl alcohol, 2-phenoxyethanol, 2-butoxyethanol, and n-propyl alcohol. In addition, it is also preferable to add a diazo solubilizer, for example, a reducing substance such as a sulfite, methylresorcin, or a pyrazolone compound. Further, there can be mentioned those described in U.S. Pat. Nos. 3,475,171 and 3,615,480. Further, JP-A-50-26601, JP-B-56-39
The developers described in JP-A Nos. 464 and 56-42860 are also excellent as developers for the photosensitive lithographic printing plate of the present invention.

As a method for developing a photosensitive lithographic printing plate image-exposed using the above-described developing solution, a developing solution is charged into a developing tank, and the photosensitive lithographic printing plate is immersed in the developing solution. A method of repeatedly using a developing solution such as a method of passing a developing solution or a method of spraying a developing solution in a developing tank, or methods described in JP-A-61-243455 and JP-A-62-2254.
As disclosed in Japanese Patent Application Laid-Open No. H10-260, an amount of a developing solution necessary for developing one photosensitive lithographic printing plate is applied to the plate surface, and the developing solution is developed only with the applied developing solution, and then the developing solution is discarded. Although various systems such as a disposable developing system that does not reuse the developing solution can be used, in the present invention, a system in which the developing solution is repeatedly used is preferable. In this case, the developing replenisher may be continuously or intermittently added. preferable. The composition of the developer and replenisher of the developing method for performing such replenishment and the replenishment method are described in JP-A-54-62004, JP-A-55-22759 and JP-A-55-22759.
Nos. 5-115039, 56-12645, 58-95349,
JP-A-64-21451, JP-A-1-180548, JP-A-2-30
No. 65, which can be suitably used in the developing method of the present invention.

Image exposure is performed by using a light-sensitive lithographic printing plate with a light source rich in ultraviolet rays such as a metal halide lamp and a high-pressure mercury lamp, and then treated with the above-described developer to remove unexposed portions of the photosensitive layer. If necessary, a desensitizing treatment after washing, a desensitizing treatment as it is, or a treatment with an aqueous solution containing an acid, followed by a desensitizing treatment to obtain a printing plate. If necessary, after development, post-exposure or burning treatment may be performed to increase the degree of crosslinking in the image area.

[0039]

The present invention will be described in more detail with reference to Synthesis Examples and Examples. "%" Indicates% by weight unless otherwise specified. Example 1 An aluminum plate having a thickness of 0.30 mm was grained with a nylon brush and an aqueous suspension of 400 mesh pumistone, and then washed thoroughly with water. 10
After immersion in 70% sodium hydroxide at 70 ° C. for 60 seconds, etching, washing with running water and neutralization washing with 20% HNO ₃ ,
Washed with water. This was subjected to electrolytic surface roughening treatment in a 1% aqueous nitric acid solution at an anode electricity of 160 coulomb / dm ² using a sinusoidal alternating waveform current under the condition of V _A = 12.7 V. When the surface roughness was measured, it was 0.6 μ (Ra display). Subsequently, it is immersed in a 30% H ₂ SO ₄ aqueous solution,
After desmutting at 55 ° C. for 2 minutes, the amount of anodic oxide film in a 20% H ₂ SO ₄ aqueous solution at a current density of 2 A / dm ² was reduced.
Anodizing was performed for 2 minutes so as to obtain 2.5 g / m ² . Then immersed in a 2.5% aqueous solution of sodium silicate at 70 ° C. for 1 minute,
Washed with water and dried.

Then, the following photosensitive composition I was applied to a weight after drying of 1.0 g / m ^2, and then coated.
After drying at 0 ° C. for 2 minutes, a negative photosensitive lithographic printing plate [A]
I got Photosensitive composition I. ○ Methyl methacrylate / N- [6- (methacryloyloxy) hexyl] -2,3-dimethylmalemit / methacrylic acid = 10/60/30 (molar ratio) Copolymer [Mw = 3.0 × 10 ⁴ (GPC)] 5 g ○ 0.30 g of sensitizer represented by the following structural formula

[0041]

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○ Dodecylbenzenesulfonate of formaldehyde human cocondensate of 4-siasophenylphenylamine and phenoxyacetic acid 0.20 g ○ 4-diazodiphenylamine hexafluorophosphate 0.15 g ○ Victoria Pure Blue BoH (Hodogaya Chemical) 0 .14 g ○ Phosphorous acid 0.03 g ○ Propylene glycol monomethyl ether 50 g ○ Methyl ethyl ketone 50 g ○ Methyl alcohol 30 g ○ Megafac F-177 (Dai Nippon Ink Chemical Industry Co., Ltd., fluorine-based nonionic surfactant) 0. 10 g of the obtained photosensitive lithographic printing plate was contact-exposed through a negative film. Exposure was performed by irradiating a 2 kw ultra-high pressure mercury lamp for 60 seconds. Then, potassium silicate 1.5
Development was carried out at 25 ° C. for 30 seconds in a weight% aqueous solution.

After washing with water, a gum solution was applied and
Printing was carried out using a KORD printing machine manufactured by the company. The results are shown in Table 1.
You. Embodiment 2. FIG. The support of Example 1 was subjected to electrolytic roughening.
Later, 30% of H_TwoSO _FourImmerse in an aqueous solution,
Desmut for 2 minutes at 55 ° C, then 20% H_ThreePO_Four
Current density 2A / dm in aqueous solution^TwoThe amount of anodic oxide film is 1.
2g / m^TwoFor 2 minutes. Incidentally
Immerse in a 2.5% aqueous solution of sodium silicate at 70 ° C for 1 minute.
Washed and dried.

Next, the following photosensitive composition II was applied and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate [B]. Photosensitive composition II. ○ N- [2- (methacryloyloxy) ethyl] -2,3-dimethylmaleimito / methacrylic acid = 65/35 (molar ratio) copolymer 5 g ○ The following sensitizer 0.6 g

[0045]

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○ (1-6-7-cumene) (7-cyclopentadienyl) iron (1+) hexafluorophosphoric acid (1-) 0.3 g ○ 2- (p-methoxyphenyl) -4, 6-bis (trichloromethyl) -S-triazine 0.15 g ○ 2,4-dinitro-5-chloro-2'-acetoamino-4'-diethylamino-5-methoxyazobenzene 0.12 g ○ propylene glycol monomethyl ether 50 g ○ Methyl ethyl ketone 50 g ○ Methyl alcohol 30 g ○ Megafac F-177 0.05 g The obtained photosensitive lithographic printing plate [B] was exposed, developed and printed in the same manner as in Example 1. Table 1 shows the results. Embodiment 3 FIG. The following photosensitive composition III was prepared on the support obtained in the same manner as in Example 1, and a photosensitive lithographic printing plate [C] was obtained in the same manner. Photosensitive composition III ○ β-cinnamyloxyethyl methacrylate / methacrylic acid = 70/30 (molar ratio) copolymer 5 g ○ Sensitizer of the following structural formula 0.4 g

[0047]

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○ Dibutylnaphthalene sulfonate of formaldehyde cocondensate of 3-methoxy-4-diazodiphenylamine and benzoic acid 0.20 g ○ Triphenylsulfonium tetrafluoroborate 0.15 g ○ Oil Blue # 603 (Oriental Chemical Co., Ltd.) 0.15 g ○ p-diethylaminoazobenzene 0.05 g ○ propylene glycol monomethyl ether 50 g ○ methyl ethyl ketone 50 g ○ Megafac F177 (Dainippon Ink Chemical Co., Ltd., fluorine-based nonionic surfactant) 0 .10 g of the resulting photosensitive lithographic printing plate [C] was prepared in the same manner as in Example 1.
Exposure, development and printing. Table 1 shows the results. Embodiment 4. FIG. 4-diazo- in the photosensitive composition I of Example 1
A photosensitive lithographic printing plate [D] was obtained in place of diphenylamine hexafluorophosphate and in place of diphenyliodonium hexafluorophosphate. This photosensitive lithographic printing plate [D] was exposed, developed and printed in the same manner as in Example 1. Table 1 shows the results
Shown in Comparative Example 1 2- (P-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine was used instead of 4-diazo-diphenylamine hexafluorophosphate in the photosensitive composition I of Example 1. Lithographic printing plate [E] was obtained in the same manner as in Example 1 except for using, and was exposed, developed and printed in the same manner as in Example 1. Table 1 shows the results. Comparative Example 2 In the photosensitive composition of Example 2, (1-6-7-cumene)
(7-cyclopentadienyl) iron (1+) hexafluorophosphoric acid (1-), 2,4-dinitro-5-chloro-2′-acetoamino-4′-diethylamino-5-methoxyazobenzene, Leuco Crystal Violet 0.1
2 g, copper phthalocyanine pigment (CI Pig. Blue 1)
Using 5), a photosensitive lithographic printing plate [F] was obtained in the same manner as in Example 2. Exposure, development, and printing were performed in the same manner as in Example 2.

Table 1 焼 き Printing out photosensitive lithographic plate ( ¹⁾ Printing plate ((D) Development Printing performance Printing power ───────────────────────────── [A] 0.12 Good Good No stain 500000 [ B] 0.14 Good Good No stain 40,000 [C] 0.13 Good Good No stain 350,000 [D] 0.08 Good Good No stain 500000 5. ──────────────────── [E] 0.03 Good Good No stain 50000 [F] -0.05 ²⁾ Pigment and crack No stain 3 150,000 residual color ants 1) Density of exposed and unexposed areas using a Macbeth densitometer Difference 2) Unlike in [A] to [E], the exposed portion develops color. The photosensitive lithographic printing plate according to the present invention has excellent printout properties. ,
Other performances were also good.

Claims (1)

(57) [Claims] 1. A photosensitive lithographic printing plate provided with a photosensitive layer containing a photocrosslinkable polymer having a maleimide group capable of photodimerization, wherein in the photosensitive layer, a compound which generates a strong acid upon exposure to light, and which is discolored by an acid. Discoloring dye (however,
Photosensitive lithographic printing plate, characterized in that it contained except equalizer dye).