JP3004378B2 - Lithographic printing plate manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a lithographic printing plate from a photosensitive lithographic printing plate, and more particularly, to developing a negative-type photosensitive lithographic printing plate with an alkali developing solution containing no organic solvent, followed by a water-soluble lithographic printing plate. And a method for producing a lithographic printing plate by desensitizing with a desensitizing liquid.

[0002]

2. Description of the Related Art A photosensitive lithographic printing plate includes a negative type and a positive type photosensitive lithographic printing plate. When developing each printing plate, it is common to use a dedicated developer. It is a target. Therefore, when processing these two types of photosensitive lithographic printing plates, two types of developing solutions were required. Further, when a large number of two types of photosensitive lithographic printing plates are subjected to development processing, two automatic developing machines and the like are required, and there is a problem in terms of installation cost, installation area, and the like, and economic efficiency.

[0003] When one of these two types of photosensitive lithographic printing plates is to be processed in common by one automatic developing machine, a developing solution is required each time according to the type of the photosensitive lithographic printing plate to be processed. Since the replacement has to be performed, there is much waste in terms of work efficiency and economy. In order to solve such a problem, a method of developing two types of photosensitive lithographic printing plates with the same developer has been proposed, but no satisfactory results have yet been obtained. The following can be considered as a reason for this. That is, generally, a developer for a positive type lithographic printing plate having a photosensitive layer composed of an o-quinonediazide compound and an alkali-soluble resin or the like is mainly composed of alkaline water having a pH of 12 or more mainly composed of silicate. When developing an unexposed portion of a negative-type lithographic printing plate comprising a water-insoluble diazo resin and an alkali-soluble resin using this developer, no development can be performed, or undeveloped portions are liable to occur, and printing is not performed. However, there is a problem that dirt is easily generated at the time of cleaning. Conversely, when developing the exposed part of the positive type lithographic printing plate with the developing solution of the negative type lithographic printing plate, similarly, the development cannot be carried out well, the residual film remains, and the printing becomes dirty, In the negative type developer, the photosensitive layer of the positive type lithographic printing plate is easily attacked by a solvent or the like contained in the negative type developer, so that the development tolerance is reduced, and the oil sensitivity and the printing durability are reduced. And had a problem.

[0004] JP-A-2-220062, JP-A-2-2-2
19060, JP-A-2-217859, JP-A-2-
189544 discloses a method of developing a negative photosensitive lithographic printing plate comprising a diazo resin and a binder with an alkaline aqueous solution having a pH of 12 or more. However, photosensitive lithographic printing plates composed of diazo resin and binder
When developing with an aqueous solution, there are many problems such as a decrease in printing durability, and a deterioration in the inking property due to the developer penetrating into the image area.

JP-A-64-56442 discloses a negative photosensitive lithographic printing plate having a photopolymerizable photosensitive layer comprising an alkali-soluble polymer, a monomer and a photopolymerization initiator. A method of developing with a developing solution is disclosed. However, the alkali-soluble polymer used in the photosensitive layer is liable to swell due to high-pH alkaline water in a developer, and has a problem of poor inking property. Furthermore, when gum arabic is used for the desensitizing solution used after the development, there is a problem that the inking property is remarkably deteriorated.

As a photocrosslinkable polymer, Japanese Patent Application Laid-Open No.
No. 2-988 (JP-B-60-37123) discloses a polymer having a dimethylmaleimide group.
No. 78544 describes a photosensitive composition comprising the above polymer and a diazo resin. However, development of a photosensitive lithographic printing plate using such a photosensitive composition is almost always performed using a developer containing an organic solvent. The reason is that when developing with a developer containing a high pH silicate containing no organic solvent, the developability is significantly reduced, or development residue tends to occur, and conversely, if the developability of the polymer is increased, , The performance as a lithographic printing plate,
This may cause a reduction in printing durability and a deterioration in the inking property.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a negative photosensitive lithographic printing plate provided with a photocrosslinkable or photopolymerizable photosensitive layer with a developer substantially free of an organic solvent. It is an object of the present invention to provide a method for producing a lithographic printing plate which is subjected to a desensitization treatment, does not generate printing stains, and has excellent inking property.

Further, the present invention provides a method for producing a negative photosensitive lithographic printing plate which can be developed with a developer for a positive photosensitive lithographic printing plate, has no stain, and has good inking property. The purpose is to:

[0009]

SUMMARY OF THE INVENTION The present invention provides a method for manufacturing a semiconductor device comprising the steps of:
After image exposure of a negative photosensitive lithographic printing plate provided with a photocrosslinkable photosensitive layer containing a photocrosslinkable polymer having a photodimerizable unsaturated bond and a sensitizer, or a photopolymerizable photosensitive layer,
After developing with an aqueous solution containing a silicate substantially free of an organic solvent having a pH of 12 or more and removing the unexposed portion of the photosensitive layer,
In the method for producing a lithographic printing plate including a step of desensitizing, a treating solution used for the desensitizing treatment comprises: (a) 5 to 30% by weight of starch phosphate and / or hydroxyalkyl starch; (b) gum arabic 0 to 3% by weight, (c) surfactant 0.01 to
2% by weight, (d) 0.01 to 2% by weight of a water-soluble salt, and (e) solvent 0.05
A method for producing a lithographic printing plate, characterized by containing 平 2% by weight.

Hereinafter, the present invention will be described in detail. The photocrosslinkable photosensitive layer used in the present invention contains a photocrosslinkable polymer having a photodimerizable unsaturated bond and a sensitizer as essential components. Examples of the photocrosslinkable polymer having a photodimerizable unsaturated bond include a maleimide group, a cinnamyl group, a cinnamoyl group, a cinnamylidene group, a cinnamylideneacetyl group, a photosensitive group having a functional group such as a chalcone group in a side chain or a main chain. Polymers.

In particular, polymers having a maleimide group in the side chain and polyester resins having a cinnamic acid skeleton in the molecular chain have relatively high sensitivity. Examples of such a polymer capable of photodimerization having a maleimide group in a side chain include:
JP-A-52-988 (corresponding US Pat. No. 4,079,041)
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:

[0012]

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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 Or a polymer having a maleimide group in the side chain represented by the following formula:
Nos. 49-128992 and 49-128993
No. 50-5376, No. 50-5377, No. 50
No.-5379, No.50-5378, No.50-5380
Nos. 53-5298, 53-5299, 53
No.-5300, No.50-50107, No.51-479
No. 40, No. 52-13907, No. 50-45076
No. 52-121700, No. 50-10884,
No. 50-45087, German Patent No. 2,349,948,
The following general formula (II) described in the specifications of JP-A-2,616,276:

[0014]

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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). I can do it. The average molecular weight of these polymers is 1000 or more, preferably 10,000 to 100,000.
These polymers have an average of two or more maleimide groups per molecule in the side chain. Solubilization of these polymers having a maleimide group in the side chain in alkaline water can be achieved by including an acid group in the polymer.

Specific examples of the acid group include carboxylic acid, sulfonic acid, phosphoric acid, phosphonic acid, alkali metal salts and ammonium salts thereof, and pK which dissociates in alkaline water.
a is an acid group of 6 to 12, specifically, -SO ₂ NHCO-, -CON
HCO -, - SO ₂ NHCOO-, include p- hydroxyphenyl group. These monomers having an acid group and a monomer having a maleimide group are, for example, 10/90 to 50/5
The photocrosslinkable polymer of the present invention can be easily obtained by copolymerization at a ratio of 0, preferably 20/80 to 40/60 (molar ratio).

The acid value of the maleimide polymer having an acid group is preferably in the range of 30 to 300, more preferably 50 to 300.
２５０250. Preferred examples of the copolymerizable monomer having an acid group include vinyl monomers having a carboxyl group such as allylic acid and methacrylic acid, maleic anhydride, and itaconic anhydride.

[0018] 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.

Of the other photocrosslinkable polymers used in 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, -CH which is sensitive to the main chain is used. Examples of those having a .dbd.CH--CO-- group include photosensitive polyesters described in U.S. Pat. No. 3,030,208, U.S. Pat. No. 3,453,237 and U.S. Pat. No. 3,622,320. There is. The above polyester is prepared by condensing a suitable polycarboxylic acid, or a lower alkyl ester of a suitable polycarboxylic acid, or a chloride with a suitable polyhydric alcohol in the presence of an esterification catalyst.

The following are examples of the products obtained by solubilizing these photocrosslinkable polymers with alkaline water. That is, the main chain as described in JP-A-60-191244 has a photodimerizable unsaturated double bond adjacent to an aromatic nucleus, a carboxyl group on a side chain and a hydroxyl group on a terminal. A chain extender having two or more functional groups capable of reacting with a hydroxyl group in the molecule, such as diisocyanate compound, diphenyl terephthalate, diphenyl carbonate and terephthaloyl bis (N
-Caprolactam) or a polyester prepolymer or polyurethane prepolymer having a main chain having a photodimerizable unsaturated double bond adjacent to an aromatic nucleus and a hydroxyl group at a terminal. And a photopolymer obtained by reacting pyromellitic dianhydride or cyclopentanetetracarboxylic dianhydride as a chain extender 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-63-25543, 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 addition amount of the photocrosslinkable polymer to the photosensitive layer is 10 to 99% by weight, preferably 50 to 99% by weight.

As the sensitizer used in the photo-crosslinkable photosensitive layer of the present invention, a triplet sensitizer having a maximum absorption that can actually sufficiently absorb light in a range of 300 nm or more is preferable. Such sensitizers include benzophenone derivatives, benzuanthrone derivatives, quinones, anthraquinones, aromatic nitro compounds, naphthothiazoline derivatives,
Benzothiazoline derivatives, xanthones, naphthothiazole derivatives, ketocoumarin compounds, benzothiazole derivatives, naphthofuranone compounds, benzoin compounds, acetophenone compounds, fluorenone compounds, pyrylium salts,
Thiapyrylium salts and the like can be mentioned. Specifically, Michler's ketone, N, N'-diethylaminobenzophenone, benzanthrone, (3-methyl-1,3-diaza-1,9-benz) anthronepiclamide, 5-nitroacenaphthene, 2-nitrofluorene, -Dibenzoylmethylene-3-methylnaphthothiazoline, 3,3-
Carbonyl-bis (7-diethylaminocoumarin),
2,4,6-triphenylthiapyrylium perchlorate, 2- (p-chlorobenzoyl) naphthothiazole,
Benzoin, benzoin methyl ether, benzoin ethyl ether, 2,2-dimethoxy-2-phenylacetophenone, 9-fluorenone, 2-chloro-9-fluorenone, 2-methyl-9-fluorenone, 9,10-
Anthraquinone, 2-ethyl-9,10-anthraquinone, 2-t-butyl-9,10-anthraquinone, 2,
6-dichloro-9,10-anthraquinone, xanthone, 2-methylxanthone, 2-methoxyxanthone,
Dibenzalacetone, p- (dimethylamino) phenylstyryl ketone, p- (dimethylamino) phenyl-p
-Methylstyryl ketone and the like.

Further, thioxanthone derivatives such as 2-
Chlorothioxanthone, 2-isopropylthioxanthone, dimethylthioxanthone, etc., and German Patent No. 301
Substituted thioxanthones such as those described in US Pat. Nos. 8891 and 3117568, and European Patent No. 33720 and British Patent No. 2075506 may be used.

Further, merocyanine dyes such as 2-
(Heterocyclylcarbonylmethylene) benzo (or naphtho) thiazoline, 2- (diheterocyclecarbonylmethylene) benzo (or naphtho) thiazonin, 2-dibenzoylmethylenebenzo (or naphtho) thiazoline, and specifically, 2- [bis (2-furoyl) methylene] -3- disclosed in JP-B-52-129791
Methylbenzothiazoline, 2- [bis (2-thenoyl)
Methylene] -3-methylbunzothiazonin, 2- [bis (2-furoyl) methylene] -3-methylnaphthothiazoline, 2- [bis (2-furoyl) methylene] -3-methylnaphthothiazoline, 2- (2-furoyl) methylene-3-methylbenzothiazoline, 2-benzoylmethylene-3-methylbenzothiazoline, 2-bis (benzoylmethylene) benzothiazoline, 2-bis (benzoylmethylene) naphthothiazoline, and JP-B-45-8832
Thiazole, benzothiazole, naphthothiazole, and benzoselenazole sensitizing dyes having a thiobarbituric acid ring disclosed in Japanese Patent Application Laid-Open No. Hei.
The sensitizer disclosed in the specification of JP-A No. 3 is useful.

In addition, a binder, a plasticizer and the like can be contained in the photosensitive layer if necessary. Specific examples of the binder include chlorinated polyethylene, chlorinated polypropylene, polyacrylic acid alkyl ester, acrylic acid alkyl ester, acrylonitrile vinyl chloride, styrene, a copolymer with at least one kind of monomer such as butadiene, polyamide, methyl cellulose. , Polyvinyl formal, polyvinyl butyral, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer and the like.

Examples of the plasticizer include dialkyl phthalates such as dibutyl phthalate and dihexyl phthalate;
Oligoethylene glycol alkyl esters, phosphate plasticizers and the like can be used. In some cases, for the purpose of coloring the photosensitive layer, a pH indicator or the like may be added as a dye or pigment or a printing-out agent.

Further, the photosensitive layer preferably contains a thermal polymerization inhibitor and an antioxidant, such as hydroquinone, p-methoxyphenol, di-tert-butyl-p-cresol, pyrogallol, and t-butylcatechol. , Benzoquinone, 4,4'-thiobis (3-methyl-6-t-
Butylphenol), 2,2'-methylenebis (4-methyl-t-butylphenol), 2-mercaptobenzimidazole, and the like.

Further, in order to enhance the adhesion to the support, or
A diazo resin can also be used to increase the crosslinking of the image area. Examples of such a diazo resin include a condensate of p-diazodiphenylamine and formaldehyde;
JP-A-48001, diazo resin co-condensed with an aromatic compound, diazo resin described in JP-A-62-283330, JP-A-1-102456, JP-A-1-102457, 1-254948,
JP-A-1-254949, JP-A-2-66, JP-A-2-29650, JP-A-2-111948, diazo resin solubilized in an alkaline aqueous solution as disclosed in each publication,
For example, a diazo resin condensed with an aldehyde having a carboxylic acid disclosed in JP-A-3-2868 can be used.

Further, malic acid, phosphorous acid, tartaric acid, citric acid, phosphoric acid, dipicolinic acid, polynuclear aromatic sulfonic acids and salts thereof, sulfosalicylic acid, and the like can be added as necessary as stabilizers for the diazo resin. . Next, the photopolymerizable photosensitive layer used in the present invention will be described. Attempts to use the photopolymerizable composition as a photosensitive layer for a lithographic printing plate are well known.

For example, a basic composition comprising a polymer as a binder, a polymerizable compound having an ethylenically unsaturated bond and a photopolymerization initiator as disclosed in JP-B-46-32714, JP-B-49-34041. JP-B-48-38403 and JP-B-53-2760, in which unsaturated double bonds are introduced into a polymer as a binder as disclosed in JP-B-58-38, and curing efficiency is improved.
Compositions using a novel photopolymerization initiator, such as those disclosed in JP-A No. 5 and UK Patent No. 1388492, are known. Various methods are used to solubilize or disperse these photopolymerizable compositions in alkaline water.

The polymer used as a binder in the present invention is soluble in alkaline water or swellable, and is benzyl (meth) acrylate / (meth) acrylic acid / need as described in JP-B-59-44615. Other addition polymerizable vinyl monomer copolymers; methacrylic acid / methyl methacrylate or ester / alkyl methacrylate copolymers as described in JP-B-54-34327; other JP-B-58-12577;
(Meth) acrylic acid copolymers as described in JP-B-54-25957 and JP-A-54-92723;
Allyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomer copolymers as described in JP-A-59-53836, described in JP-A-59-71048. In a polymer such as maleic anhydride copolymer to be added with pentaerythritol triacrylate by half-esterification or vinyl methacrylate / methacrylic acid / other addition-polymerizable vinyl monomer copolymer if necessary. COOH, -PO ₃ H ₂ , -SO
₃ H, -SO ₂ NH _2, have a -SO ₂ NHCO- group, acid value of 50 to 200
And acidic vinyl copolymers of the above.

In particular, among these, benzyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomer copolymers and allyl (meth) acrylate / (meth) acrylic acid / optional Other addition-polymerizable vinyl monomer copolymers are preferred. These polymers can be used alone or as a mixture of two or more. The molecular weight of a high-molecular polymer can take a wide range of values depending on the type of the polymer, but in general,
5,000 to 1,000,000, preferably 10,000 to 500,000 are suitable. The amount of the polymer used is 10% to 90%, preferably 30 to 85%, based on the entire photopolymerizable composition.
It is.

[0034] Included in the photopolymerizable composition. A polymerizable compound having an ethylenically unsaturated bond is a compound having at least one ethylenically unsaturated bond in its chemical structure, and is a monomer, a prepolymer, that is, a dimer,
Those having a chemical form such as trimers and other oligomers, mixtures thereof, and copolymers thereof. Examples thereof include unsaturated carboxylic acids and salts thereof, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds,
Examples include amides of unsaturated carboxylic acids and aliphatic polyamine compounds.

Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid and maleic acid. Salts of unsaturated carboxylic acids include the alkali metal salts of the aforementioned acids, for example, sodium and potassium salts. Specific examples of the ester of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include acrylates such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, Propylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate,
1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate,
Examples include dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, and polyester acrylate oligomer. As methacrylic acid esters, tetramethylene glycol dimethacrylate, trimethylene glycol dimethacrylate,
Trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol dimethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, Screw-
[P- (3-methacryloxy-2-hydroxypropoxy) phenyl] dimethylmethane, bis [p- (methacryloxyethoxy) phenyl] dimethylmethane and the like. Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate, and the like. Examples of the crotonic acid ester include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, sorbitol tetracrotonate and the like. As isocrotonic acid esters, ethylene glycol diisocrotonate, pentaerythritol diisocrotonate,
And sorbitol tetraisocrotonate.
Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate. Furthermore, a mixture of the above-mentioned esters can also be mentioned.

Specific examples of the amide of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-
Hexamethylenebis-acrylamide, 1,6-hexamethylenebis-methacrylamide, diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide and the like.

As another example, see JP-B-48-417.
JP-A-08-0832, a polyisocyanate compound having two or more isocyanate groups in one molecule and a hydroxyl-containing vinyl monomer represented by the following general formula (III) added to one molecule, Vinyl urethane compounds containing the above polymerizable vinyl groups are exemplified. CH ₂ CC (R ⁵ ) C00CH ₂ CH (R ⁶ ) OH (III) (where R ⁵ and R ^{6 each} represent a hydrogen atom or a methyl group.) The photopolymerization initiator used in the present invention includes: Bicinal polyketaldonyl compounds disclosed in U.S. Pat. No. 2,367,660, U.S. Pat. No. 2,367,66
Α and No. 2,367,670.
Carbonyl compounds, the acyloin ethers disclosed in U.S. Pat. No. 2,448,828, U.S. Pat.
No. 2,722,512 discloses an aromatic acyloin compound in which the α-position is substituted with a hydrocarbon, US Pat.
Polynuclear quinone compounds disclosed in 3,046,127 and 2,951,758, U.S. Pat. No. 3,549,36
7, a combination of a triarylimidazole dimer / p-aminophenyl ketone disclosed in U.S. Pat. No. 3,870,524, a benzothial compound disclosed in U.S. Pat. No. 3,870,524, and U.S. Pat. No. 4,239,850. Compounds / Trihalomethyl-s-triazine Compounds and U.S. Pat.
Acridine and phenazine compounds disclosed in U.S. Pat. No. 1,259, and oxadiazole compounds disclosed in U.S. Pat. No. 4,212,970, and the like. About 0.5% by weight to about 15% by weight of
Preferably, it is in the range of 2 to 10% by weight.

In addition to the above, it is preferable to further add a thermal polymerization inhibitor to the photosensitive layer.
-Methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4- Methyl-
6-t-butylphenol), 2-mercaptobenzimidazole and the like are useful, and in some cases, a dye or pigment for coloring the photosensitive layer and a pH as a printing agent.
An indicator or the like can be added.

Further, it is desirable to add the above-mentioned diazo resin in order to enhance the adhesion to the support. Further, as a stabilizer of diazo resin, malic acid, phosphorous acid, tartaric acid,
If necessary, citric acid, phosphoric acid, dipicolinic acid, polynuclear aromatic sulfonic acid and salts thereof, sulfosalicylic acid, and the like can be added. Further, a wax agent can be added in order to prevent the polymerization inhibition effect due to the influence of oxygen in the air. What is used as a waxing agent is a material which is solid at room temperature but is dissolved in a coating solution and precipitates on the surface during a coating and drying process. Examples include higher fatty acids such as stearic acid and behenic acid, higher fatty acid amides such as stearic acid amide and behenic acid amide, and other higher alcohols.

In order to completely prevent the polymerization inhibition effect due to oxygen in the air, a protective layer made of a polymer having excellent oxygen barrier properties such as polyvinyl alcohol and acidic celluloses may be provided. For a method of applying such a protective layer, see, for example, US Pat. No. 3,458,311.
And Japanese Patent Publication No. 55-49729.

The photocrosslinkable or photodimerized photosensitive layer is obtained by adding the above-mentioned photosensitive composition to, for example, 2-methoxyethanol, 2-methoxyethanol,
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, ethanol, methyl cellosolve acetate, etc. It is formed by dissolving in a solvent alone or a mixed solvent in which these are appropriately combined, and coating the solution on a support. The coating weight of about 0.1 g / m ² ~ about 10g in weight after drying / m ²
Is appropriate, and preferably 0.5 to 5 g / m ² .

In the present invention, an intermediate layer may be formed, if necessary, for the purpose of enhancing the adhesion between the support and the photosensitive layer, preventing the photosensitive layer from remaining after development, or preventing halation. It may be provided. In order to improve the adhesion, the intermediate layer is generally made of a diazo resin, a phosphate compound adsorbed on aluminum, a silane coupling agent, or the like. The intermediate layer made of a substance having high solubility so that the photosensitive layer does not remain in the developer is generally made of a polymer having good solubility or a water-soluble polymer. Furthermore, for antihalation, the intermediate layer generally contains dyes and UV absorbers. The thickness of the intermediate layer is arbitrary, and must be a thickness capable of performing a uniform bond-forming reaction with the upper photosensitive layer upon exposure. Usually about 1 to 1 in dry solid
Applying a rate of 200 mg / m ² good, 5 to 40 mg / m ² is particularly favorable.

The surface of the photosensitive layer of the present invention may be further subjected to a matting process to enhance the adhesion to the film.
For these, the compounds and methods described in JP-A-55-12974 and JP-A-58-182636 can be used. The support used in the present invention is desirably a dimensionally stable plate. Such dimensionally stable plate-like materials include those conventionally used as a support for a printing plate, 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, and triacetic acid. Cellulose, cellulose propionate, cellulose acetate, cellulose acetate butyrate,
Examples include a plastic film such as cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, and the like, and a paper or plastic film on which a metal is laminated or vapor-deposited as described above.
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 to 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 a graining treatment and an anodizing treatment is performed. In order to enhance the hydrophilicity of the surface, it is preferable to perform immersion 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, an aluminum plate as described in JP-B-47-5125. After anodic oxidation, an immersion treatment in an aqueous solution of an alkali metal silicate is also preferably used.

Electrodeposition of a silicate as described in US Pat. No. 3,658,662 is also effective.
Further, Japanese Patent Publication No. 46-27481, Japanese Patent Application Laid-Open No.
Japanese Patent Application Laid-Open No. 58602 and JP-A-52-30503 also provide a surface treatment using a support provided with electrolytic grains and a combination of the anodic oxidation treatment and the sodium silicate treatment.

Further, as disclosed in JP-A-56-28893, brush grains, electrolytic grains,
It is also preferable to perform anodizing treatment and then sodium silicate treatment in this order. Further, after these treatments have been performed, a water-soluble resin such as polyvinylphosphonic acid, a polymer and a copolymer having a sulfonic acid group in the side chain, and an undercoat of polyacrylic acid are also suitable. Further, Japanese Patent Laid-Open No. 2-23
No. 348 and Japanese Patent Application No. 2-151858 are also suitable.

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. The aqueous solution containing a silicate having a pH of 12 or more, which is substantially free of an organic solvent and is a phenomenon liquid used in the present invention, contains sodium silicate, potassium silicate, lithium silicate, ammonium silicate, and the like, and is preferably It is an aqueous solution containing potassium silicate.
Also, inorganic alkalis such as sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium phosphate tribasic, sodium phosphate dibasic, ammonium phosphate tribasic, ammonium phosphate dibasic, sodium metasilicate, sodium bicarbonate, etc. The agent and an organic amine compound such as monoethanolamine, diethanolamine and triethanolamine may be used alone or in combination. these,
The concentration of the alkaline agent is 0.1 to 10% by weight, preferably 0.1 to 10% by weight.
It is added so as to be 5 to 5% by weight.

Further, a surfactant, an organic solvent and the like can be added to this aqueous solution as needed. In the present invention, "contains substantially no organic solvent" means that the organic solvent content is 1% or less in the working solution. Examples of the anionic surfactant include higher alcohol sulfates having 8 to 22 carbon atoms, such as sodium salts of lauryl alcohol sulfate, sodium salts of octyl alcohol sulfate, ammonium salts of lauryl alcohol sulfate, and sodium sulphate, such as cetyl. Aliphatic alcohol sulfates such as alcohol sulfates, such as sodium salts of alkyl alcohol sulfonates such as sodium salts of dodecylbenzenesulfonic acid, isopropylnaphthalenesulfonic acid, and sodium salts of metanitrobenzenesulfonic acid. For example, C ₁₇ H ₃₃ CON (CH ₃ ) CH ₂ CH ₂ SO ₂
Examples include sulfonates of alkylamides such as Na and the like, and sulfonates of dibasic fatty acid esters such as dioctyl sodium sulfosuccinate and dihexyl sodium sulfosuccinate.

Examples of the amphoteric surfactant include an alkylcarboxybetaine type alkylaminocarboxylic acid type, an alkylimidazoline type compound and Japanese Patent Publication No. 1-578.
No. 95, and the like. Further, Japanese Patent Application Laid-Open Nos.
Non-ionic surfactants disclosed in JP-A-175758, and cationic surfactants disclosed in JP-A-62-17557.

The surfactant is suitably contained in the range of 0 to 3% by weight based on the total weight of the developing solution at the time of use. As the organic solvent, those having a solubility in water of about 10% by weight or less are suitable, and preferably selected from those having a solubility of 2% by weight or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenylpropanol-1, 4-phenylbutanol-1, 4-phenylbutanol-2, 2-phenylbutanol-1, 2-phenoxyethanol, 2-benzyloxyethanol, o
-Methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 4-methylcyclohexanol and 3-
Methylcyclohexanol and the like can be mentioned.

Further, if necessary, alkali-soluble
Mercapto compounds and / or thioether compounds,
Additives such as water-soluble reducing agents, defoamers and water softeners,
A coloring agent and the like can be contained. As water softener
Is, for example, Na_TwoP_TwoO₇, Na_FiveP_ThreeO_Three, Na_ThreeP_ThreeO₉, Na_TwoO_FourP (NaO_Three
P) PO _ThreeNa_Two, Calgon (poly sodium metaphosphate)
Polyphosphates, such as ethylenediaminetetraacetic acid,
Potassium salt and its sodium salt; diethylenetriamine
Pentaacetic acid, its potassium and sodium salts; triethyl
Lentramine hexaacetic acid, its potassium salt, its nato
Lithium salt; hydroxyethyl ethylenediamine trivinegar
Acid, its potassium salt, its sodium salt; nitrilotri
Acetic acid, its potassium salt, its sodium salt; 1,2-di
Aminocyclohexanetetraacetic acid, its potassium salt,
Sodium salt of 1,3-diamino-2-propanol
Tetraacetic acid, its potassium salt, its sodium salt, etc.
Such aminopolycarboxylic acids can be mentioned.

The optimum amount of such a water softener varies depending on the hardness of the hard water used and the amount used. 5
%, More preferably 0.01 to 0.5% by weight. Examples of the water-soluble reducing agent include hydroquinone, phenolic compounds such as methoxyquinone, phenylenediamine, amine compounds such as phenylhydrazine,
Alternatively, sulfites such as sodium sulfite, potassium sulfite, and sodium hydrogen sulfite; phosphites such as potassium phosphite and potassium hydrogen phosphite; sodium thiosulfate; sodium dithionite;
The content is preferably 0.01 to 10% by weight based on the total weight of the developer.

An alkali-soluble mercapto compound and / or
Alternatively, the thioether compound is preferably a compound having one or more mercapto groups and / or thioether groups in the molecule and having at least one acid group, and more preferably one or more mercapto groups in one molecule. And a compound having a carboxyl group. For example, mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 4-mercaptobutanoic acid, 2,4-dimercaptobutanoic acid, 2-mercaptotetradecanoic acid,
-Mercaptomyristic acid, mercaptosuccinic acid, 2,
3-dimercaptosuccinic acid, cysteine, N-acetylcysteine, N- (2-mercaptopropionyl) glycine, N- (2-mercapto-2-methylpropionyl) glycine, N- (3-mercaptopropionyl) glycine, N- ( 2-mercapto-2-methylpropionyl) cysteine, penicillamine, N-acetylpenicillamine, glycine / cysteine / glutamine condensate, N-
(2,3-dimercaptopropio-1,3,4-thiadiazole, 4-mercaptobenzenesulfonic acid, N-
(2-Mercapto-2-methylpropionyl) cysteine, cysteine and the like are preferable. The content in the developer composition is 0.001% to 10% by weight, preferably 0.01% by weight.
~ 5% by weight is suitable.

As a method of 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 through a developing tank or a method of spraying a developing solution in a developing tank;
Applying an amount of developing solution necessary to develop one photosensitive lithographic printing plate to the plate surface as disclosed in US Pat.
After development using only the applied developer, various methods such as a disposable developing method in which the developer is discarded and not reused are possible.In the present invention, a method in which the developer is repeatedly used is used. Preferably, in this case, it is preferable to add the developing replenisher continuously or intermittently. 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 and JP-A-55-62004.
No. 22759, No. 55-115039, No. 56-12
Nos. 645, 58-95349, 64-21451
And JP-A-1-180548 and JP-A-2-3065, which can be suitably used in the developing method of the present invention.

The desensitizing agent used in the present invention removes the alkali developing solution component adhering to the developed lithographic printing plate, and changes the non-image portion of the plate to a property that is easily compatible with water. Also, it has an effect of preventing the image portion and the non-image portion from being scratched or stained. The desensitizing solution used in the present invention comprises (a) 5 to 30% by weight of modified starch,
(b) 0-3% by weight of gum arabic, (c) 0.01 of surfactant
To 2% by weight, (d) 0.01 to 2% by weight of water-soluble salt, (e) solvent
It contains 0.05 to 2% by weight and water.

The modified starch contained in the desensitizing solution used in the present invention includes roasted starch such as white dextrin, yellow dextrin and pretish gum, enzyme-modified dextrin such as enzyme dextrin and Shardinger dextrin, and solubilized starch. Acid-degraded starch shown in the above, oxidized starch shown in dialdehyde starch, pregelatinized starch such as modified pregelatinized starch and non-denatured pregelatinized starch, phosphate starch, fat starch, sulfate starch, nitrate starch, xanthate starch and carbamine Esterified starch such as acid starch, carboxyalkyl starch, hydroxyalkyl starch, sulfoalkyl starch,
Etherified starch such as cyanoethyl starch, allyl starch, benzyl starch, carbamylethyl starch and dialkylamialkyl starch, crosslinked starch such as methylol crosslinked starch, hydroxyalkyl crosslinked starch, phosphate crosslinked starch and dicarboxylic acid crosslinked starch, starch polyacrylamide Copolymer, starch polyacrylic acid copolymer, starch polyvinyl acetate copolymer, starch polyacrylonitrile copolymer,
Cationic starch polyacrylate copolymer,
Starch graft copolymers such as cationic acid starch vinyl polymer copolymer, starch polystyrene maleic acid copolymer and starch polyethylene oxide copolymer.

Of these modified starches, roasted starch, enzyme dextrin, enzyme-modified dextrin, starch phosphate, and etherified starch are preferred because they do not reduce the oil sensitivity of the image area. These may be used alone or in combination of two or more. The weight in the desensitizing solution is 5 to 30% by weight, more preferably 7% by weight.
-20% by weight.

In the present invention, gum arabic used as necessary in the desensitizing solution is used to enhance the coverability of the plate surface and the desensitizing property. However, when used in excess, the oil sensitivity of the image area is lost. In particular, as in the present invention, the photosensitive layer in the image area, which has been developed with a high pH alkaline silicate, has a hydrophilic property. Causes a decline. Therefore, it is preferably 0 to 3% by weight, more preferably 0 to 2% by weight.

In the present invention, as the surfactant contained in the desensitizing solution, an anionic surfactant and a nonionic surfactant are suitably used. Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyrene phenyl ether, polyoxyethylyl polyoxypropylene alkyl ether, glycerin fatty acid partial esters, sorbitan fatty acid partial esters Pentaerythritol fatty acid partial esters, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester, Polyoxyethylated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanol Bromide include, N, N-bis-2-hydroxyalkylamines,
Examples include polyoxyethylene alkylamine, triethanolamine fatty acid ester, and trialkylamine oxide.

Examples of the anionic surfactant include fatty acid salts, abithiates, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, straight-chain alkylbenzenesulfonates, branched-chain alkylbenzenesulfonates, and alkylnaphthalenes. Sulfonates, alkylphenyloxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-
Oleyltaurine sodium, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonate, sulfate castor oil, sulfated cowfoot oil, sulfate of fatty acid alkyl ester, alkyl sulfate salt,
Polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates , Polyoxyethylene alkyl phenyl ether phosphate salts, partially saponified styrene-maleic anhydride copolymers, partially saponified olefin-maleic anhydride copolymers, naphthalene sulfonate formalin condensates, etc. I can list them.

In addition, if necessary, cationic surfactants such as alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, polyethylene polyamine derivatives, carboxybetaines, aminocarboxylic acids, sulfobetaines, Amphoteric surfactants such as aminosulfates and imidazolines may be added.

Of these, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acids Partial esters, pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene glycerin fatty acid partial esters, polyethylene glycol fatty acid esters, polyoxyethylated castor oil, dialkyl sulfo Succinates, alkylbenzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfates, polyoxy Tylenealkylamine salts are preferred because they also have a function of suppressing the decrease in oil sensitivity of the image area of the lithographic printing plate. Among them, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyrene phenyl ethers, glycerin fatty acid partial esters, and sorbitan Particularly preferred are fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, polyethylene glycol fatty acid esters, dialkyl sulfosuccinates, and alkyl sulfates. Among the nonionic surfactants, those having an HLB of 14 or less are preferred because they have a high effect of stabilizing the emulsion, and the HLB is preferably 11 or less. These surfactants can be used alone or in combination of two or more. Particularly, alkylphenyl-type nonionic surfactants represented by polyoxyethylene alkylphenyl ethers and polyoxypropylene dialkylphenyl ethers and dialkyl sulfo Combination of succinates, combination of fatty acid ester type surfactants and dialkyl sulfosuccinates, and combination use of alkylphenyl nonionic surfactants, fatty acid ester type surfactants and dialkyl sulfosuccinates are insensitive. It is preferable because not only the emulsification is easy at the time of the production of the fat, but also the effect of suppressing the decrease in the oil sensitivity of the image area appears in a redundant manner.

The surfactant is used in an amount of about 0.01 to about 2% by weight, more preferably 0.05, based on the total weight of the desensitizing solution.
It can be used in the range of ２2% by weight. The desensitizing solution used in the present invention preferably contains a water-soluble salt. Thereby, when the plate surface protective agent of the present invention is applied to a lithographic printing plate, the non-image portion becomes more hydrophilic. Suitable water-soluble salts include the alkali metal and ammonium salts, and those which provide particularly good results include the water-soluble alkali metal salts of acids such as acetic acid, molybdic acid, boric acid, nitric acid, sulfuric acid, phosphoric acid and polyphosphoric acid. Salts and ammonium salts. Specifically, ammonium acetate, sodium acetate, potassium acetate, sodium molybdate, potassium molybdate, sodium borate, ammonium borate, lithium nitrate, sodium nitrate, potassium nitrate, sodium phosphate monobasic, sodium phosphate dibasic, sodium phosphate tertiary, Potassium monophosphate, potassium diphosphate, potassium tertiary phosphate,
Examples include ammonium tertiary phosphate and sodium polyphosphate. Of the above, particularly preferred are potassium acetate, sodium borate, ammonium borate, potassium nitrate, sodium molybdate, potassium molybdate,
Potassium sulfate.

These water-soluble salts can be used alone or in combination of two or more, and are preferably about 0.01 to about 2% by weight, more preferably about 0.01 to about 2% by weight, based on the total weight of the plate surface protective agent of the present invention.
It is used in the range of 0.1 to 1% by weight. The desensitizing solution of the present invention contains a solvent as a lipophilic substance in order to improve the inking property of the image area. These include polyhydric alcohols, alcohols and aliphatic hydrocarbons.

Among the polyhydric alcohols, preferred specific examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, and sorbitol. Examples of the alcohol include propyl alcohol and butyl Examples thereof include alkyl alcohols such as alcohol, pentanol, hexanol, heptanol, and octanol, and alcohols having an aromatic ring such as benzyl alcohol, phenoxyethanol, and phenylaminoethyl alcohol.

Examples of the aliphatic hydrocarbon include n-hexanol, methyl amyl alcohol, 2-ethylbutanol, n-heptanol, 3-heptanol, 2-octanol, 2-ethylhexanol, nonanol,
3,5,5-trimethylhexanol, n-decanol, undecanol, n-dodecanol, trimethylnonyl alcohol, tetradecanol, peptadecanol, 2-ethyl-1,3-hexanediol, 1,6-
Hexanediol, 2,5-hexanediol, 3,4
-Hexanediol, 1,8-octanediol, 1,
Examples thereof include 9-nonanediol and 1,10-decanediol.

In addition, a plasticizer, a fatty acid, a fatty oil, a wax, and a lipophilic resin may be added to the desensitizing agent as required. Preferred plasticizers include phthalic acid diesters such as dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di- (2-ethylhexyl) phthalate, dinonyl phthalate, didecyl phthalate, dilauryl phthalate, butyl benzyl phthalate and the like. For example, dioctyl azelate, dioctyl adipate, dibutyl glycol adipate, dibutyl sebacate, di- (2-ethylhexyl) sebacate,
Aliphatic dibasic acid esters such as dioctyl sebacate, for example, epoxidized triglycerides such as epoxidized soybean oil, for example, tricresyl phosphate, trioctyl phosphate, phosphate esters such as trischlorethyl phosphate, for example, Benzoic acid esters such as benzyl benzoate are included. Of these, particularly preferred are dioctyl adipate, dibutyl sebacate and dioctyl azelate, which are highly safe without odor.

Preferred fatty acids include caproic acid, enanthic acid, cabrilic acid, helargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, Arachiic acid, behenic acid, lignoselenic acid, cerotic acid, heptacosanoic acid, montanic acid,
Saturated fatty acids such as melisic acid, lacceric acid, isovaleric acid and acrylic acid, crotonic acid, isocrotonic acid, undecylenic acid, oleic acid, elaidic acid, setreic acid, erucic acid, brassic acid, sorbitan acid, linoleic acid, linolenic acid, There are unsaturated fatty acids such as arachidonic acid, propiolic acid, stearic acid, succinic acid, tallic acid, ricanoic acid and the like. Preferred waxes include carnauba wax, beeswax, whale wax, insect white wax, wool wax, shellac wax and the like.

Specific examples of preferred lipophilic resins include novolak type phenol resins such as phenol formaldehyde resin, cresol formaldehyde resin, t-butylphenol formaldehyde resin, xylene resin obtained by condensing phenol and xylene with formaldehyde, and phenol and mesitylene. Resin, polyhydroxystyrene, brominated polyhydroxystyrene, cashew resin, partially esterified copolymer of styrene and maleic anhydride, melamine resin, alkyd resin, polyester resin, epoxy resin,
Rosin, modified rosin such as hydrogenated rosin and rosin ester, petroleum resins such as Gilsonite,
Of these, novolak-type phenol resins, rosins and modified rosins are preferred.

In addition to the above-mentioned modified starch, natural polymers, semi-natural (semi-synthetic) polymers,
You may add a cellulose derivative etc. Natural polymers include starches such as potato starch, potato starch, tapioca starch, wheat starch and corn starch,
Carrageenan, Laminaran, Sea Soumannan, Nobori,
Irish moss, those obtained from algae such as agar and sodium alginate, microbial mucilage such as homopolysaccharides such as trolloay, mannan, quince seed, pectyl, dextran, glucan and levan, and heteropolysaccharides such as succinoglucan and xanthan gum; Examples include glue gelatin, casein and collagen sugar proteins. Semi-natural products (semi-synthetic products) include, in addition to propylene glycol alginate, viscose, methylcellulose, ethylcellulose, methylethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxypropylethylcellulose and hydroxypropylmethylcellulose phthalate. And the like.

In addition, pH adjustment,
An acid may be added for the purpose of hydrophilicity. For example, phosphoric acid,
Mineral acids such as sulfuric acid and nitric acid, for example, citric acid, phosphonic acid,
Phenylphosphonic acid, tannic acid, malic acid, glacial acetic acid,
Organic acids such as lactic acid, silicic acid and p-toluenesulfonic acid are preferred. Of these, phosphoric acid is particularly excellent because it not only functions as a pH adjuster, but also has an action of preventing contamination of non-image areas, and is 0.1 to 8% by weight based on the total weight of the aqueous phase. Preferably, it is contained in the range of 0.5 to 5% by weight.

In addition to the above, a preservative, an antifoaming agent and the like can be added to the plate surface protective agent of the present invention. As a preservative, for example, benzoic acid and its derivatives, phenol formalin, sodium dehydroacetate and the like can be added in the range of 0.005 to 2.0% by weight. As the defoaming agent, various defoaming agents such as silicone resin type, lower alcohol type, organic polar compound type and mineral oil type are used.

The desensitizing agent used in the present invention can be produced in any type of emulsion type, non-emulsion type or suspension type by appropriately selecting a surfactant, a lipophilic substance, a water-soluble polymer and the like to be contained. In Although,
When the content of gum arabic is reduced as in the present invention, the emulsion is inferior in stability. Therefore, the non-emulsion type is preferred.

Various methods can be used for the treatment with the fat-insensitive agent, such as a dipping method, a method of applying with a roller, and a method of spraying from a number of nozzles and spraying the PS plate or roller. By repeatedly using or using a small amount of an unused desensitizing agent each time the processing is performed, it is possible to greatly reduce the amount of the desensitizing agent used per PS plate subjected to plate making. The amount used in the treatment method in which the desensitizing agent is repeatedly supplied and used on a lithographic printing plate is preferably from 1 liter / minute to 40 liter / minute. More preferably, it is 3 to 20 liters / minute. In addition, in the method of supplying an unused desensitizer little by little to the lithographic printing plate for each treatment and treating the lithographic printing plate, it is necessary to uniformly supply the desensitizer to the lithographic printing plate and use it. The amount of the desensitizing agent is preferably 1 liter or less per plate, more preferably 300 ml or less. Also,
Such a desensitizing treatment tank may be single or plural, and in the case of two or more, each treatment liquid may be different.

The lithographic printing plate treated with the desensitizing agent is desirably squeegeeed so that the applied amount of the desensitizing agent and the amount of the coated film are as uniform and appropriate as possible. Desirable coating amount is high in performance of preventing fingerprint adhesion on the plate surface.
ml / m ² or more, a is 20 ml / m ² or less can be easily removed only a small amount of water the desensitizing agent before printing.
More preferably, the coating amount is 3 ml / m ² or more at which the performance of preventing scratches on the plate surface appears, and 10 ml / m ² or less at which coating unevenness is reduced including the edges (commonly referred to as ears) of the lithographic printing plate. is there. As a method of squeegeeing the plate surface of a lithographic printing plate, for example, a method of scraping out a liquid with an air knife, or coating an elastic material such as rubber on the roller surface, passing the lithographic printing plate between a pair of elastic rollers, and applying a nip pressure to the plate surface It is possible to adopt a method of removing liquid, or a method of arranging an elastic material with a smooth surface along the transport of the lithographic printing plate and scraping the liquid on the plate surface by sliding the plate surface. It is. A more effective squeegee method is a method in which a lithographic printing plate is passed between a pair of elastic rollers and a load is applied between the pair of rollers. More preferably, a third load roller is further placed on the roller pair. Examples of the elastic material include natural rubber, cis-polyisoprene rubber, styrene butadiene rubber, cis-polybutadiene, chloroprene, butyl rubber, nitrile butadiene rubber, ethylene propylene rubber, hyvalon (chlorosulfonated polyethylene), acrylic rubber, urethane rubber, silicone rubber, Examples include fluoro rubber, neoprene rubber, polysulfide rubber, and plastics. Butyl rubber, nitrile butadiene rubber, ethylene propylene rubber, acrylic rubber, silicone rubber, fluorine rubber, and polysulfide rubber have excellent oil resistance and are therefore suitable for the roller in the desensitization treatment section.

In a method of squeegeeing a lithographic printing plate through a pair of elastic rollers, more preferably in a method of performing desensitization processing by ejecting from a number of nozzles, the lithographic printing plate is subjected to desensitization processing after completion of the desensitization processing. After passing, the processing apparatus is preferably designed so that at least one of the conveyance by the pair of rollers and the ejection by the nozzle is stopped (hereinafter simply referred to as a stop) in order to save unnecessary power. However, it is not rare that the plate surface desensitizing agent accumulates in the contact portion of the roller pair during this rest period and is dried and solidified. In this case, when the processing of the next planographic printing plate is restarted, the applied film thickness of the desensitizing agent tends to be uneven. As a method of avoiding this situation, a method in which the roller pair is rotated while the desensitizing agent treatment is stopped, and a number of nozzles are used to rotate the roller pair during the treatment and / or while the treatment is stopped. It is preferable to take at least one method such as a method of spraying a desensitizing agent to the roller to delay the drying of the roller pair.

It is preferable that the lithographic printing plate treated with the desensitizing agent is dried so as not to attach dust or the like, or to facilitate handling. Preferred drying temperatures are between 20C and 120C. The lithographic printing plate obtained in this way can be subjected to processes such as developing ink filling, brushing, erasing-washing, erasing-water-washing and desensitization before printing, if necessary.

The image exposure is performed on the photosensitive lithographic printing plate using 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-mentioned developer to remove unexposed portions of the photosensitive layer. If necessary, after washing with water or as it is, a desensitizing treatment is performed to obtain a printing plate.

[0079]

According to the present invention, a negative-working photosensitive lithographic printing plate is developed with an alkali silicate aqueous solution substantially free of an organic solvent, and then the lithographic printing plate is excellent in inking property and stain resistance. Is obtained. That is, a lithographic printing plate without a decrease in printing performance can be obtained even when the lithographic printing plate is processed with a conventional developer for a positive photosensitive lithographic printing plate.

[0080]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. "%" Indicates% by weight unless otherwise specified. Example 1 An aluminum plate of 1S material having a thickness of 0.30 mm was grained with a nylon brush and an aqueous suspension of pumicestone of 400 mesh, and washed thoroughly with water. After etching by immersion in a 10% aqueous sodium hydroxide solution at 70 ° C. for 60 seconds, the substrate was washed with running water, neutralized with 20% HNO ₃ , and washed with water. This was converted to 160 coulombs / cm 2 in a 1% aqueous nitric acid solution using a sinusoidal alternating current under the condition of V _A = 12.7 V.
Electrolytic surface-roughening treatment was performed with an anode charge of dm ² . When the surface roughness was measured, it was 0.6 μ (Ra indication). Subsequently, it was immersed in a 30% H ₂ SO ₄ aqueous solution,
After desmutting at 2 ° C. for 2 minutes, it was anodized in a 20% H ₂ SO ₄ aqueous solution at a current density of 2 A / dm ² for a thickness of 2.7 g / m ² for 2 minutes. The obtained aluminum support was immersed in a 2.5% aqueous solution of sodium silicate at 70 ° C. for 1 minute, washed with water and dried.

Next, the following photopolymerizable photosensitive composition (1) was used:
Using a spin coater, 2.0 g / m2 as dry weight^TwoWill be
And dried at 80 ° C for 2 minutes to form a photosensitive layer.
Was. Photosensitive composition (1) Poly (allyl methacrylate / 5.0 g methacrylic acid) copolymerization molar ratio 70/30 Pentaerythritol tetraacrylate 1.5 g The following photopolymerization initiator 0.3 g

[0082]

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3-methoxy-4-diazo-diphenylamine- 0.2 g Hexafluorophosphate-formaldehyde resin p-methoxyphenol 0.01 g Oil Blue # 603 (manufactured by Orient Chemical Industries) 0.15 g Megafax F-177 0.05 g (a fluorosurfactant manufactured by Dainippon Ink and Chemicals, Inc.) ethylene glycol monomethyl ether 100 g methyl ethyl ketone 50 g methanol 50 g Finally, polyvinyl alcohol for the overcoat layer (saponification degree: 86.5 to 89.0 mol%, A 3% by weight aqueous solution having a degree of polymerization of 1000 or less) was applied to the surface of the photosensitive layer so as to have a dry weight of 1.5 g / m ² to produce a photosensitive lithographic printing plate [A].

The obtained photosensitive lithographic printing plate was applied to a negative film and a step wedge (density difference 0.15, density step number 15).
And exposure was carried out through contact. Then, [SiO ₂ ] /
A developing solution of an aqueous solution (pH = about 13) of 1.5% by weight of potassium silicate having a molar ratio of [K] of 0.5 and a desensitizing solution described below were prepared. -Desensitizing solution-o White dextrin 50g o Hydroxypropyl etherified starch 100g o Gum arabic (adjusted by dissolving in 14 ° Be) 10g o Ammonium phosphate 1.0g o Sodium dilauryl succinate 1.5g o Poly Oxyethylene nonyl phenyl ether 5 g o Ethylene glycol 10 g o EDTA 0.05 g o Dehydroacetic acid 0.05 g o Water 1000 g Put these processing solutions into PS plate automatic developing machine PS-900 manufactured by Fuji Photo Film Co., Ltd. At a temperature of 30 ° C. and a development immersion time of 12 seconds, development, rinsing, and desensitization drying were performed to obtain a lithographic printing plate. This printing plate was attached to a KOR-D printing machine manufactured by Heidelberg to perform printing. Table 1 shows the results. Example 2 Using the same AL support as in Example 1, the following photocrosslinkable photosensitive composition was prepared.

O Methyl methacrylate / N- [6- (methacrylic 5 g royloxy) hexyl] -2,3-dimethylmaleimide / methacrylic acid = 10/60/30 (molar ratio) copolymer o Increased compound represented by the following structural formula Sensitizer 0.25g

[0086]

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O Benzoic acid-3-methoxy-4-diazo-di 0.15 g Dibutylnaphthalene sulfonate of formaldehyde cocondensate of phenylamine o Megafax F-177 (Dai Nippon Ink 0.03 g Chemical Industry Co., Ltd.) Fluorine nonionic surfactant) o Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.13 g o 4-diazodiphenylamine hexafluorophosphate 0.10 g o Propylene glycol monomethyl ether 50 g o Methyl ethyl ketone 50 g The photosensitive composition was applied on the aluminum support using a spin coater to a weight after drying of 1.2 g / m ^2, and dried at 80 ° C. for 2 minutes to obtain a photosensitive composition. A lithographic printing plate [B] was obtained.

The obtained photosensitive lithographic printing plate [B] was exposed, developed and desensitized in the same manner as in Example 1 to obtain a lithographic printing plate. This was attached to a printing machine for printing. Table 1 shows the results. Example 3 Using the same AL support as in Example 1, the following photocrosslinkable photosensitive composition was prepared. -Photosensitive composition- o N- [6- (methacryloyloxy) hexyl] -5 g 2,3-dimethylmaleimide / methacrylic acid = 65/35 (molar ratio) copolymer o 0.3 g of the following sensitizer

[0089]

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O 4-diazodiphenylamine and phenoxy 0.10 g dodecyl benzenesulfonate of formaldehyde copolymer of acetic acid (weight average molecular weight 2500) o phenylphosphonic acid 0.02 g o dipicolinic acid 0.02 g o 3-methoxy-4 0.05 g of diazodiphenylamine hexafluorophosphate o Victoria Pia Blue BOH 0.12 g o Megafax F-177 (0.30 g from Dainippon Ink and Chemicals, Inc.) o 40 g propylene glycol monomethyl ether o 40 g methyl ethyl ketone o Methanol 20 g This photosensitive composition was applied on the aluminum support using a spin coater to a weight after drying of 1.0 g / m ² and dried at 80 ° C. for 2 minutes. did. Thereafter, the surface was matted according to the method described in Example 1 of JP-A-58-182636 to obtain a photosensitive lithographic printing plate [C].

The following developer and desensitizing solution were prepared. - developer - o [SiO _2] / sodium silicate mole ratio 0.4 1.5 wt% aqueous solution o following organic boron compound of (Na) 0.01 wt%

[0092]

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O Sodium ethylenediaminetetraacetate 0.1 wt%-Desensitizing solution-o Starch phosphate 10 g o Cream dextrin 50 g o Hydroxypropyl etherified starch 70 g o Ammonium phosphate 1.0 g o Phosphoric acid 0.5 g o Benzyl alcohol 10 g o Ethylene glycol 10 g o Sodium dilauryl succinate 2 g o Polyoxyethylene nonyl phenyl ether 5 g o EDTA 0.3 g o Preservative (benzoic acid) 0.3 g o Silicone-based defoamer KS502 0.5 g (Shin-Etsu Chemical Industry (manufactured by) o Water 800 g These processing solutions were put into a PS-plate automatic developing machine PS-800EII manufactured by Fuji Photo Film Co., Ltd., and exposed to light in the same manner as in Example 1 to develop a photosensitive lithographic printing plate. And a lithographic printing plate was obtained. The printing plate thus obtained was attached to a printing press in the same manner as in Example 1 and printing was performed.

Table 1 shows the results. Example 4 Using the same aluminum support as in Example 1, the following photosensitive composition was prepared. -Photosensitive composition-o β-cinnamyloxyethyl methacrylate / 5.0 g Methacrylic acid = 70/30 (molar ratio) copolymer o 0.3 g of the following sensitizer

[0095]

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O 0.15 g of a diazo resin represented by the following structural formula

[0097]

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O F-177 (Dainippon Ink Co., Ltd.) 0.2 g o Copper phthalocyanine pigment (CI Pigment Blue 15) 1.0 g plasticizer 10% dispersion o diethyl phthalate 0.5 g o methyl ethyl ketone 20 g o propylene glycol monomethyl Ether 30 g This photosensitive composition was applied using a spin coater so that the weight after drying was 1.0 g / m ² and dried at 80 ° C. for 2 minutes. The surface was matted according to the method of Example 1 to obtain a photosensitive lithographic printing plate [D].

In the same manner as in Example 3, development, desensitization treatment and printing were performed. Table 1 shows the results. Comparative Example Printing was carried out in the same manner as in Examples 1 to 4, except that the desensitizing solution was replaced with a 5% by weight aqueous solution of gum arabic instead of the desensitizing solution used in Examples 1 to 4. Table 1 shows the results.

Table 1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Lithographic printing plate 〃 〃 〃 [A] [B] [C] [D] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Actual printing start 7 sheets 6 sheets 5 sheets 5 sheets Same as left Same as left Same as left ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Ratio 50 sheets at the start of printing 30 sheets 30 sheets 30 sheets Comparison of the number of inlaid sheets Example 1 Non-image area stains Same as left Same as left Same as left ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━ as described above, the printing plate according to the present invention, excellent inking property at the time of printing, also, stains in the non-image area without any, are superior to printability.

Claims (1)

(57) [Claims] 1. A photo-dimerizable unsaturated bond on a support.
Crosslinking Containing Photo-Crosslinkable Polymer Having Sensitizer
After imagewise exposing a negative photosensitive lithographic printing plate provided with a photosensitive photosensitive layer, or a photopolymerizable photosensitive layer, developing treatment with an aqueous solution containing a silicate substantially free of an organic solvent having a pH of 12 or more and an unexposed portion In the method for producing a lithographic printing plate comprising a step of desensitizing after removing the photosensitive layer of (a), the processing solution used for the desensitizing treatment comprises (a) starch phosphate and / or hydroxyalkyl starch 5 to 30. Wt%, (b) 0-3 wt% gum arabic, (c) 0.01-2 wt% surfactant, (d) 0.01 water-soluble salt
A method for producing a lithographic printing plate, characterized in that the lithographic printing plate further comprises: