JPH11327156A - Method and agent for treating photosensitive planographic printing plate and photosensitive planographic printing plate treated with the agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent micro-dotted soil (stop soil) from occurring on a non-image portion at the time of restarting printing operation after a certain time of suspension of a printing machine because of a discussion, intermission and the like during the printing operation using a planographic printing plate fabricated from a photosensitive planographic printing plate. SOLUTION: (1) In or after development, the printing plate is treated with a solution containing a polymer having a side chain of a polyoxyethylene group of two or more repeating units, and a polymer having a side chain of a polyoxypropylene group of two or more repeating units. (2) In or after development of a photosensitive planographic printing plate, the printing plate is treated with a solution containing the poplymers described in (1). (3) A developing solution for a photosensitive planographic printing plate containing the polymers described in (1), and a correcting solution and a plate surface protecting agent for a planographic printing plate obtained from the photosensitive planographic printing plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a photosensitive lithographic printing plate and a processing agent used in the processing method. The present invention relates to a technique for improving fine spot-like stains (stop stains) generated in a non-image portion when a printing press is stopped during printing and printing is restarted.

[0002]

2. Description of the Related Art A lithographic printing method is a printing method that utilizes the fact that water and oil are not essentially mixed. An image area receiving the oily ink repulsively is formed, and printing is performed by supplying water and the oily ink from the printing machine and transferring only the oily ink received in the image area to paper. The printing press used for such lithographic printing is generally an offset printing method in which the oil-based ink received in the image portion of the printing plate surface is once transferred to a rubber blanket, and then transferred to paper. In general, a photosensitive lithographic printing plate is used for the preparation.

Conventionally, as a support used for a photosensitive lithographic printing plate, a support excellent in hydrophilicity, water retention and adhesion to a photosensitive layer has been required from the viewpoint of printability. Therefore, an aluminum plate that has been subjected to a surface roughening process, which is generally called graining, is used. A surface roughening method and an electrochemical surface roughening method in which the surface of a support is electrolytically treated with an alternating current or a direct current in an acidic electrolyte such as hydrochloric acid or nitric acid are known. Since the aluminum plate grained by such a method is relatively soft and easily worn as it is, it is subjected to anodizing treatment after graining to form an oxide film. The surface of the aluminum plate treated in this manner is hard and has excellent wear resistance.

[0004] The photosensitive lithographic printing plate is conventionally provided with a photosensitive layer containing an o-quinonediazide compound as a photosensitive component on an aluminum plate treated in this manner, for example, in a positive photosensitive lithographic printing plate. Widely known. It is known that an o-quinonediazide compound is converted into a carboxylic acid by exposure to ultraviolet light. When the compound is developed with an aqueous alkali solution, only the exposed portion of the photosensitive layer is removed and the surface of the support is exposed. Since the surface of the aluminum support is hydrophilic, a portion (non-image portion) where the surface of the support is exposed by development receives water and repels oil-based ink. On the other hand, the portion (image portion) from which the photosensitive layer has not been removed by development is lipophilic and repels water to receive oil-based ink.

When printing is performed using a lithographic printing plate prepared from such a photosensitive lithographic printing plate, after the printing press has been stopped for a while due to consideration during printing work, breaks, and the like, the non-image area is returned when printing is resumed. (Hereinafter referred to as "stop stain"), and in order to prevent such stains, a method of maintaining the hydrophilicity of the plate surface of the non-image area is desired.

Conventionally, aqueous solutions of alkali metal silicates have been widely used for the development of photosensitive lithographic printing plates, and the hydrophilicity of the support surface is increased by the reaction between aluminum on the support surface and silicic acid in the developer. The preferred range of silicate concentration is disclosed in JP-A-55-22759, JP-A-5-22759.
No. 2,273, and the like. However,
With this method alone, the hydrophilicity was not sufficiently maintained, and stop stains could not be completely suppressed.

[0007] In the lithographic printing plate, an unnecessary image which is inevitably generated or an image portion which needs to be deleted and corrected may occur.
It needs to be fixed. For example, overexposure and underexposure occur on the printing plate surface due to, for example, stains, scratches, cuts, and the like on the original film, which results in unnecessary image portions, which need to be corrected. Japanese Patent Laid-Open Publication No. Sho 54-1979 discloses a correcting agent for removing unnecessary image portions of a lithographic printing plate.
No. 89806 and Japanese Patent Publication No. 5-2231.

However, since the correction solution slightly dissolves the aluminum support plate surface, the hydrophilicity of the correction mark is reduced, and the stop stain cannot be completely suppressed.

When a lithographic printing plate is made, a plate surface protective agent is applied in the final step. The purpose of applying the plate surface protective agent is to not only protect the hydrophilicity of the non-image area,
Image correction such as retouching or erasing of image area, preservation until printing after plate making or preservation until reuse, prevention of dirt caused by adhesion of fingerprints, oils, dusts, etc. when attaching to a printing press or during handling This is to protect against the occurrence of scratches and the like, and also to suppress the occurrence of oxidized stains.

Heretofore, as a plate surface protective agent for a lithographic printing plate, gum arabic, cellulose gum or an aqueous solution of a water-soluble polymer having a carboxyl group in a molecule has been generally used. In addition, a plate surface protective agent containing a phosphoric acid-modified starch is described in JP-A-62-11693 and the like, and a plate surface protective agent containing a carboxyalkylated starch is described in JP-A-62-7595 and the like. Also,
Many plate surface protective agents containing a water-soluble polymer compound have been proposed. However, with these methods alone,
The hydrophilicity of the non-image area plate surface was not sufficiently maintained, and stop stains could not be completely suppressed.

[0011]

The problem to be solved by the present invention is that when printing using a lithographic printing plate prepared from a photosensitive lithographic printing plate, the printing press is stopped for a while, such as during a study or a break. An object of the present invention is to provide a technique for preventing minute spot-like stains (stop stains) generated in a non-image portion when printing is restarted.

[0012]

Means for Solving the Problems The inventors of the present invention have found that a lithographic printing plate which is less likely to cause stop stains can be obtained by applying a solution containing a specific polymer described later to the plate surface of the lithographic printing plate. It has been found that the present invention has been reached.

The present invention that achieves the above object has the following (1) to
(5).

(1) A polymer having a polyoxyethylene group having 2 or more repeating units in the side chain or a polymer having a polyoxypropylene group having 2 or more repeating units in the side chain during or after the development treatment. A photosensitive lithographic printing plate which has been treated with a solution containing the same.

(2) A polymer having a polyoxyethylene group having two or more repeating units in the side chain or a polyoxypropylene having two or more repeating units in the side chain during or after the development of the photosensitive lithographic printing plate. A method for treating a photosensitive lithographic printing plate, comprising treating with a solution containing a polymer having a group.

(3) Photosensitivity characterized by containing a polymer having a polyoxyethylene group having two or more repeating units in a side chain or a polymer having a polyoxypropylene group having two or more repeating units in a side chain. Lithographic printing plate developer.

(4) Photosensitivity comprising a polymer having a polyoxyethylene group having two or more repeating units in a side chain or a polymer having a polyoxypropylene group having two or more repeating units in a side chain. Correction liquid for lithographic printing plates.

(5) a polymer having a polyoxyethylene group having two or more repeating units in a side chain or a polymer having a polyoxypropylene group having two or more repeating units in a side chain;
A plate surface protective agent for a photosensitive lithographic printing plate, comprising:

Hereinafter, the present invention will be described in detail.

In the present invention, a polymer having a polyoxyethylene group having two or more repeating units in the side chain or a polymer having a polyoxypropylene group having two or more repeating units in the side chain (hereinafter referred to as "polymer of the present invention") ), The repeating unit of the oxyethylene group in the polyoxyethylene group and the repeating unit of the oxypropylene group in the polyoxypropylene group are each preferably 2 to 10. If the repetition is small, a sufficient effect on the stop stain cannot be obtained, and if the repetition is too large, the effect on the stop stain is exerted, but the sensitivity is reduced due to the effect of suppressing the development of the oxyethylene group or the oxypropylene group. Problems can arise. In the main chain of the polymer compound, the proportion of the repeating unit having a polyoxyethylene group or a polyoxypropylene group in the side chain is 10 to 80.
mol% is preferred.

The main chain structure includes acrylic resin, vinyl resin, silicone resin, polyamide, polysiloxane, polycarbonate, epoxy resin, phenol novolak resin, polyurethane, pyrogallol acetone resin, condensation of phenols with aldehydes or ketones. Resins, acetal resins and the like. A particularly preferred structure of the main chain is a structure comprising a copolymer of an acrylic monomer or a vinyl monomer.

Specific examples of the monomer which gives a polyoxyethylene group or a polyoxypropylene group in a side chain by forming a copolymer include the following.

[0023]

Embedded image

[0024]

Embedded image

The polymer of the present invention preferably contains 0.001 to 10%, more preferably 0.001 to 2%, in a solution for processing a photosensitive lithographic printing plate.
If the amount is less than 0.001%, the effect of the present invention cannot be obtained, and 1
If it is more than 0%, not only no further effect can be obtained but also it becomes insoluble in the solution.

The solution containing the polymer of the present invention includes:
Examples include a processing solution (developer) for developing the photosensitive lithographic printing plate subjected to image exposure, and a processing solution (for example, a correction solution, a plate surface protection solution, etc.) applied to the plate surface of the lithographic printing plate obtained by development. In the treatment method of the present invention, at least one of these treatment solutions may contain the polymer of the present invention.

The developer containing the polymer of the present invention is not particularly limited, and may be any processing solution used for imagewise eluting and removing the photosensitive layer of a photosensitive lithographic printing plate that has been image-exposed. Examples of such a developer include a developer containing a generally used alkali metal silicate. The alkali metal of the alkali metal silicate includes lithium, sodium and potassium.

Preferred developers (including development replenishers)
[SiO ₂ ] / [M] (where [SiO ₂ ] is S
indicates the molar concentration of iO _2, [M] represents the molar concentration of the alkali metal) is 0.15 to 1.0, with 0.5 to 5.0 wt% SiO ₂ concentration of the total weight An aqueous solution of a certain alkali metal silicate is used. In addition, [S
iO _2] / [M] is 0.25~0.75, SiO ₂
When the concentration is 1.0 to 4.0% by weight,
O _2] / [M] is 0.15 to 0.5, SiO ₂ concentration include developer is 1.0 to 3.0 wt%. If the SiO ₂ concentration is too low than the above range, the buffering property of the solution is weak and the development stability is deteriorated, and when the plate support is aluminum, aluminum is eluted. Conversely, if the SiO ₂ concentration is too high, it will not dissolve in the developing solution or scum is likely to occur during running processing. [SiO ₂ ] /
If [M] is too low, the alkali is too strong and film burrs tend to occur in the image portion of the plate. Conversely, if [M] is too high, the alkali is too weak and poor development occurs.

The developer can contain a water-soluble or alkali-soluble organic or inorganic reducing agent. Examples of the organic reducing agent include phenol compounds such as hydroquinone, methol and methoxyquinone, and amine compounds such as phenylenediamine and phenylhydrazine.Examples of the inorganic reducing agent include sodium sulfite and potassium sulfite. Sulfites such as ammonium sulfite, sodium bisulfite, potassium bisulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, potassium hydrogen phosphite, sodium dihydrogen phosphite, potassium dihydrogen phosphite And the like, hydrazine, sodium thiosulfate, sodium dithionite and the like. These water-soluble or alkali-soluble reducing agents can be contained in the developer at 0.05 to 10% by weight.

The developer may contain an organic acid carboxylic acid. The organic acid carboxylic acid includes an aliphatic carboxylic acid having 6 to 20 carbon atoms and an aromatic carboxylic acid having a benzene ring or a naphthalene ring substituted with a carboxyl group.

The aliphatic carboxylic acids include those having 6 to 2 carbon atoms.
The alkanoic acid of 0 is preferable, and specific examples thereof include caproic acid, enantiic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mystyric acid, palmitic acid,
Stearic acid and the like are particularly preferable.
~ 12 alkanoic acids. Further, the aliphatic carboxylic acid may be a fatty acid having a double bond in a carbon chain or a fatty acid having a branched carbon chain. The aliphatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

Specific compounds of aromatic carboxylic acids include benzoic acid, o-chlorobenzoic acid, p-chlorobenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, p-tert-butylbenzoic acid, o-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5
-Dihydroxybenzoic acid, gallic acid, 1-hydroxy-
2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2
-Hydroxy-1-naphthoic acid, 1-naphthoic acid, 2-
Naphthoic acid and the like. The aromatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

The aliphatic carboxylic acid and the aromatic carboxylic acid can be usually contained in an amount of 0.1 to 30% by weight.

The developer may contain various anionic, nonionic or cationic surfactants and an organic solvent, and may contain other known additives.

The correction liquid containing the polymer of the present invention is a liquid substantially consisting of a solvent that dissolves or swells the image area. Preferred solvents for dissolving or swelling the image area include lactones, ethers, ketones, alcohols, and hydrocarbon solvents. Lactones include butyrolactone, valerolactone and hexanolactone, and ethers include glycol ethers. For example, 2-methoxyethanol, 2
-Glycol monoalkyl ethers such as ethoxyethanol, 2-isopropoxyethanol and 2-butyl glycol, for example, glycol monoaryl ethers such as 2-phenylethanol, for example, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether , Diethylene glycol monobutyl ether,
Diethylene glycol monoalkyl ethers such as diethylene glycol monoisobutyl ether; for example, triethylene glycol monoalkyl ethers such as triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and triethylene glycol monobutyl ether; ethylene such as ethylene glycol dimethyl ether; Glycol dialkyl ethers such as diethylene glycol dialkyl ethers such as diethylene glycol diethyl ether such as diethylene glycol dimethyl ether and diethylene glycol diethyl ether are included. Ketones include, for example, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl butyl ketone, methyl isobutyl ketone, ethyl butyl ketone, butyrone, methyl amyl ketone, methyl hexyl ketone, valerone, mesityl oxide, diacetone alcohol, cyclohexanone, methyl Cyclohexanone, acetophenone, isophorone, acetylacetone, acetonylacetone and the like are included. As alcohols, for example, methanol, ethanol,
Butanol, octyl alcohol, benzyl alcohol and the like. Examples of the hydrocarbon-based solvent include hydrocarbon solvents having a boiling point of about 120 to 250 ° C in petroleum fractions such as toluene, xylene, turpentine, n-heptane, and solvent naphtha, for example, kerosene and mineral spirits. Besides these, N, N-dimethylformamide, tetrahydrofuran, dioxane, N-methylpyrrolidone, dimethylsulfoxide and the like can also be mentioned.

The above various image solvents and swelling agents can be used alone or in combination of two or more. The solvent is suitably contained in the range of 20 to 90% by weight, more preferably 30 to 85% by weight based on the total weight of the correction liquid.

The correction liquid of the present invention may contain modified polyvinyl alcohol. The modified polyvinyl alcohol may be at least one selected from polyvinyl alcohol modified with a carboxyl group, a sulfo group, a phosphono group, a silanol group, or a derivative thereof, and a quaternary ammonium salt of polyvinyl alcohol. The modified polyvinyl alcohol is a hydroxyl group of polyvinyl alcohol or a hydrogen atom of the group or a hydrogen atom bonded to a carbon atom of polyvinyl alcohol, a carboxyl group, a sulfo group, a phosphono group or a silanol group or a derivative of these groups, Or fourth
It is a compound substituted with an ammonium salt residue.

Specific examples of such modified polyvinyl alcohol include the following compounds.

(1) Carboxyl group (-COONa) -modified polyvinyl alcohol, commercially available as Gohsenal T-330 (trade name, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) (2) Sulfo group (-SO ₃ Na) -modified polyvinyl alcohol Alcohol, as a commercial product, Gohselan L-3266 (trade name, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) (3) phosphono group-modified polyvinyl alcohol, for example, polyvinylphosphonic acid (4) quaternary ammonium salt residue-modified polyvinyl alcohol, As a commercially available product, Gosefimer K-210 (trade name, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) (5) Silanol group-modified polyvinyl alcohol, and as a commercially available product, R-2105 (trade name, manufactured by Kuraray Co., Ltd.) The content of polyvinyl alcohol is preferably 0.05 to 25% by weight based on the total weight of the correction fluid. Preferably from 1 to 15 wt%.

The correction fluid can contain a surfactant, if necessary. The surfactant promotes better penetration of the components contained in the correction solution into the image area of the lithographic printing plate, and furthermore, the components contained in the erasing solution mix well to form a stable solution. It is effective to get it.
Examples of such surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ether, polyoxyethylene 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, oxyethyleneoxypropylene block copolymer, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester , Polyglycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene glycol Nonionic surfactants such as phosphorus fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides, and fatty acids Salts, avicenates, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, straight-chain alkylbenzenesulfonates, branched-chain alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropyl Sulfonates, polyoxyethylene alkylsulfophenyl ether salts, N-methyl-N-oleyltaurine sodium, N-alkylsulfosuccinic acid monoamide disodium , Petroleum sulfonates, sulfated castor oil, sulfated cowfoot oil, sulfates of fatty acid alkyl esters, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl Ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates,
Anions such as polyoxyethylene alkylphenyl ether phosphate salts, partially saponified styrene-maleic anhydride copolymers, partially saponified olefin-maleic anhydride copolymers, and naphthalene sulfonate formalin condensates Surfactants, alkylamine salts,
Cationic surfactants such as quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives; amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. No. Among the surfactants mentioned above, the term "polyoxyethylene" can be read as a polyoxyalkylene such as polyoxymethylene, polyoxypropylene, or polyoxybutylene.

Among these, a nonionic surfactant and an anionic surfactant are preferable, and a surfactant having an HLB of 9 or more is more preferable because each component contained in the erasing solution is mixed well. Further, polyoxyethylene alkyl phenyl ethers, oxyethylene oxypropylene block copolymer, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyerythylene glycol fatty acid ester, polyglycerin fatty acid partial ester, This is preferable because the effect of eliminating the image portion of the erasing liquid is improved.

Most preferred are oxyethylene oxypropylene block copolymers. These surfactants may be used alone or as a mixture of two or more kinds, and are contained preferably in the range of 1 to 40% by weight, more preferably 3 to 25% by weight, based on the total weight of the correction fluid of the present invention. .

The correction liquid of the present invention can contain a coloring agent, an acidic substance, water, a viscosity modifier and the like in addition to the above-mentioned components.

The colorant can be contained when visual contrast is desired. Specific examples include dyes such as crystal violet, safranin, brilliant blue, malachite green, and acid rhodamine B, as well as inorganic pigments and organic pigments. There are pigments and the like. These coloring agents are used in an amount of 0.0001 to 0.0 based on the total weight of the correction fluid of the present invention.
It is used in an amount of 5% by weight, preferably 0.001 to 0.01% by weight.

Examples of the acidic substance include hydrofluoric acid, hydrochloric acid,
Inorganic acids such as sulfuric acid, persulfuric acid, nitric acid, permanganic acid, phosphoric acid, borofluoric acid, hydrofluoric acid, acetic acid, citric acid, malic acid, lactic acid, oxalic acid, trichloroacetic acid, tannic acid, phytic acid Organic acids such as p-toluenesulfonic acid and phosphonic acid and salts thereof and the like. Of these acidic substances, hydrofluoric acid, phosphoric acid, borofluoric acid or salts thereof are preferred for improving the correcting effect. These acidic substances can be used alone or in combination of two or more, and 0.1 to 15% by weight based on the total weight of the correction fluid,
Preferably, it is contained in the range of 0.3 to 8.0% by weight.

In the correction fluid of the present invention, water is contained in various components such as acid and is added inevitably.
It may be added separately. A preferred water content is 1 to 30% by weight, more preferably 3 to 20% by weight based on the total weight of the correction fluid.
% By weight.

Examples of the viscosity modifier include inorganic thickeners such as fine silica powder, modified cellulose such as methylcellulose, hydroxypropylmethylcellulose and carboxymethylcellulose / Na salt, gum arabic, polyvinylpyrrolidone, polyvinylmethylether and polyethylene glycol. And high molecular compounds such as polypropylene glycol, vinyl methyl ether-maleic anhydride copolymer, and vinyl acetate-maleic anhydride copolymer.
Among them, modified cellulose, polyvinylpyrrolidone and the above-mentioned two kinds of maleic anhydride copolymers are preferred, and modified cellulose such as hydroxypropylmethylcellulose and polyvinylpyrrolidone are most preferred. These viscosity modifiers can be used alone or as a mixture of two or more kinds, and the amount of addition can be changed so as to obtain a desired viscosity.
%, More preferably in the range of 1 to 15% by weight.

As the plate surface protective agent of the present invention, a liquid having a composition in which the polymer of the present invention is added to a known plate surface protective agent can be used.

The plate surface protective agent of the present invention contains a hydrophilic polymer compound having a function as a protective agent for preventing scratches and stains on the plate after development, and an acid or a buffer for removing an alkali component of the developer. And a chelating agent, a lubricant, a preservative, a solubilizing agent, and the like.

As the hydrophilic polymer compound, any compounds which can be used in known gum solutions can be suitably used. For example, gum arabic, cellulose derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and their modified products, polyvinyl alcohol and its derivatives, polyvinylpyrrolidone, polyacrylamide and its copolymers, vinyl methyl ether / maleic anhydride copolymer Examples include a polymer, a vinyl acetate / maleic anhydride copolymer, and a styrene / maleic anhydride copolymer.

A surfactant can be contained in the plate surface protective agent of the present invention. Examples of the surfactant include an anionic surfactant and / or a nonionic surfactant. For example, as anionic surfactants, fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts,
Alkane sulfonates, dialkyl sulfosuccinates, linear alkylbenzene sulfonates, branched alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N -Methyl-N-oleyltaurine sodium, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonate, nitrated castor oil, sulfated tallow oil, sulfate of fatty acid alkyl ester, alkyl nitrate ester, polyoxyethylene Alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene starch Phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, partially saponified styrene-maleic anhydride copolymers, olefin-maleic anhydride Examples thereof include partially saponified copolymers and naphthalene sulfonate formalin condensates.
Of these, dialkyl sulfosuccinates, alkyl sulfates and alkyl naphthalene sulfonates are particularly preferably used. As nonionic surfactants, polyoxyethylene alkyl ethers,
Polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyrylphenyl ether, polyoxyethylene polyoxypropylene alkyl ether,
Glycerin fatty acid partial ester, sorbitan fatty acid partial ester, pentaerythritol fatty acid partial ester, 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 esters, polyglycerin fatty acid partial esters,
Polyoxyethylated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamine, triethanolamine fatty acid ester, trialkylamine oxide And the like. Among them, polyoxyethylene alkyl phenyl ethers, polyoxyethylene-polyoxypropylene block polymers and the like are preferably used. In addition, fluorine-based or silicon-based anionic or nonionic surfactants can be used in the same manner. Two or more of these surfactants can be used in combination. For example, two or more different types can be used in combination. For example, a combination of two or more different anionic surfactants or a combination of an anionic surfactant and a nonionic surfactant is preferable. The amount of the surfactant used is not particularly limited, but is preferably 0.01 to 20% by weight.

The plate surface protective agent solution of the present invention may contain a polyhydric alcohol, alcohol and aliphatic hydrocarbon as a lubricant, if necessary, in addition to the above components. Preferred specific examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol,
Propylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, sorbitol and the like, as the alcohol, propyl alcohol,
Examples thereof include alkyl alcohols such as butyl alcohol, pentanol, hexanol, heptanol and octanol, and alcohols having an aromatic ring such as penzyl 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, heptadecanol, 2-ethyl-1,3-hexanediol, 1,6-
Hexanediol, 2,5-hexanediol, 2,4
-Hexanediol, 1,8-octanediol, 1,
Examples thereof include 9-nonanediol and 1,10-decanediol. The content of these lubricants is 0.1% in the composition.
1 to 50% by weight, more preferably 0.5 to 3.0% by weight
Is appropriate.

The plate surface protective agent of the present invention may further comprise, if necessary, a lubricant such as ethylene glycol, propylene glycol, triethylene glycol, butylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane or dimethylol. Glycerin and the like are preferably used. These wetting agents may be used alone or in combination of two or more. Generally, it is preferred that the wetting agent be used in an amount of 1 to 25% by weight.

In general, it is more advantageous to use the plate surface protective agent of the present invention in the acidic range of pH 3 to 6. In order to adjust the pH to 3 to 6, it is generally adjusted by adding a mineral acid, an organic acid or an inorganic salt to the post-treatment liquid. The addition amount is preferably 0.01 to 2% by weight. For example, mineral acids include nitric acid, sulfuric acid, phosphoric acid, and metaphosphoric acid. or,
Organic acids include citric acid, acetic acid, oxalic acid, malonic acid, p
-Toluenesulfonic acid, tartaric acid, malic acid, lactic acid, levulinic acid, phytic acid and organic phosphonic acids. Further, as inorganic salts, magnesium nitrate, monobasic sodium phosphate, dibasic sodium phosphate, nickel sulfate,
Sodium hexamethane, sodium tripolyphosphate, and the like. At least one kind or two or more kinds of mineral acids, organic acids or inorganic salts may be used in combination.

Preservatives, antifoaming agents, and the like can be added to the plate surface protective agent of the present invention. For example, as a preservative, phenol or a derivative thereof, formalin, an imidazole derivative, sodium dehydroacetate, 4-isothiazoline-3
-One derivatives, benzoisothiazolin-3-one, benzotriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, derivatives such as pyridine, quinoline, guanidine, etc., diazines, triazole derivatives, oxazoles, oxazine derivatives and the like. A preferable addition amount is an amount stably exerting an effect on bacteria, molds, yeasts and the like, and varies depending on the kind of bacteria, molds and yeasts. It is preferably in the range of 4 to 4% by weight, and it is preferable to use two or more preservatives in combination so as to be effective against various molds and sterilization. Further, as the defoaming agent, a silicone defoaming agent is preferable. Among them, any of emulsification dispersion type and solubilization can be used. The optimum range is 0.01 to 1.0% by weight based on the plate surface protective agent during use.

The plate surface protective agent of the present invention may further contain a chelate compound. Preferred chelating compounds include, for example, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt; diethylenetriaminepentaacetic acid, its potassium salt, its sodium salt; triethylenetetraminehexaacetic acid, its sodium salt; triethylenetetraminehexaacetic acid, its potassium Salt, its sodium salt, hydroxyethylethylenediaminetriacetic acid, its potassium salt, its sodium salt: nitrilotriacetic acid, its sodium salt; 1-hydroxyethane-1,
Organic phosphonic acids or phosphonoalkanetricarboxylic acids such as 1-diphosphonic acid, its potassium salt, its sodium salt; aminotri (methylenephosphonic acid), its potassium salt, its sodium salt and the like can be mentioned. Organic amine salts are also effective in place of the sodium and potassium salts of the above chelating agents. These chelating agents are selected from those which are stably present in the gum solution composition and do not inhibit printability. 0.001 to 1.0% by weight
Is appropriate.

The plate surface protective agent of the present invention includes, in addition to the above components,
If necessary, a sensitizer may be contained. For example, hydrocarbons such as turpentine oil, xylene, toluene, loheptane, solvent naphtha, kerosene, mineral spirit, and a petroleum fraction having a boiling point of about 120 ° C. to about 250 ° C., for example, dibutyl phthalate, dihebutyl phthalate, di-n
Phthalic acid diesters such as octyl phthalate, di (2-ethylhexyl) phthalate, dinonyl phthalate, didecyl phthalate, dilauryl phthalate, butyl benzyl phthalate and the like, for example, dioctyl adipate, butyl glycol adipate, dioctyl azelate, dibutyl sebacate, Aliphatic dibasic acid esters such as di (2-ethylhexyl) sebacate and dioctyl sebacate, for example, epoxidized triglycerides such as epoxidized soybean oil, for example, tricresyl phosphate, trioctyl phosphate, trischlorethyl phosphate And the like. For example, a plasticizer having a freezing point of 15 ° C. or less and a boiling point of 300 ° C. or more at 1 atm.

Further, caproic acid, enanthic acid, caprylic acid, helargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid,
Saturated fatty acids such as palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachiic acid, behenic acid, lignoceric acid, cerotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, isovaleric acid, and acrylic acid, crotonic acid, Such as isocrotonic acid, undecylenic acid, oleic acid, elaidic acid, setreic acid, nilucic acid, butesidic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, propiolic acid, stearolic acid, succinic acid, tallic acid, and licanoic acid Also included are unsaturated fatty acids. More preferably a fatty acid that is liquid at 50 ° C.,
More preferably, it has 5 to 25 carbon atoms, and most preferably, it has 8 to 21 carbon atoms. These sensitizers can be used alone or in combination of two or more. The preferred range is 0.01 to 10% by weight, and the more preferred range is 0.05 to 5% by weight.

The plate surface protective agent as described above may be emulsified and dispersed and may be contained as its oil phase, or may be solubilized with the aid of a solubilizing agent.

The solid concentration of the plate surface protective agent of the present invention is 5 to 3
0 g / l is preferred. The thickness of the plate surface protective agent can be controlled by the conditions of the squeezing means of the automatic developing machine. The coating amount of the plate surface protective agent is preferably from 1 to 10 g / m ² . If the coating amount exceeds 10 g / m ² , the plate surface needs to be extremely high in temperature in order to dry in a short time, which is disadvantageous in cost and safety, and the effect of the present invention can be sufficiently obtained. Absent. If the amount is less than 1 g / m ² , uniform coating becomes difficult, and stable processability cannot be obtained.

In the treatment with the plate surface protective agent of the present invention,
The time from the end of the application of the plate surface protective agent to the start of drying is preferably 3 seconds or less. More preferably, it is 2 seconds or less, and the shorter this time is, the better the ink deposition property is. As a drying method, a known drying method such as a warm air heater or a far infrared heater can be used. In the drying step, the solvent in the plate surface protective agent needs to be dried. Therefore, it is necessary to secure a sufficient drying temperature and heater capacity.
The temperature required for drying depends on the components of the plate surface protective agent, but when the solvent is water, the drying temperature is usually preferably 55 ° C. or higher. The heater capacity is often more important than the drying temperature, and the capacity is preferably 2.6 kW or more in the case of the hot air drying method. The larger the capacity, the better,
2.6 to 7 kW is preferable in consideration of cost.

Next, the photosensitive lithographic printing plate to which the solution containing the polymer of the present invention is applied and the lithographic printing plate obtained therefrom will be described.

The support used for the photosensitive lithographic printing plate to which the solution containing the polymer of the present invention is applied includes a support made of pure aluminum and an aluminum alloy. Various aluminum alloys can be used,
For example, an alloy of aluminum with a metal such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, titanium, sodium, or iron can be used.

The aluminum support is preferably subjected to a degreasing treatment prior to roughening to remove oils, fats, rust, dust and the like on the aluminum surface. Examples of the degreasing treatment include solvent degreasing using trichlene, thinner, or the like, and emulsion degreasing treatment using an emulsion such as kerosene, triethanol, or the like. In addition, an alkaline aqueous solution such as caustic soda can be used to remove stains and natural oxide films that cannot be removed only by the above degreasing treatment.

When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, smut is formed on the surface of the support.
Alternatively, it is preferable to perform a desmut treatment by immersing in a mixed acid thereof.

The surface roughening method includes a method of mechanically roughening the surface, a method of electrochemically roughening the surface, and a method of roughening the surface with an etching agent comprising an alkali, an acid, or a mixture thereof. A roughening method can be used, and a method combining these methods can also be used.

The mechanical surface roughening method includes, for example, ball polishing,
Methods such as brush polishing, blast polishing, buff polishing, and honing polishing can be used. Among these, brush polishing and honing polishing are preferable. Further, the sheet can be roughened by pasting a previously roughened sheet to the surface of the support and applying a pressure to transfer the rough surface pattern.

As the electrochemical surface roughening method, there is a method in which the surface is electrolytically treated by alternating current or direct current in an acidic electrolytic solution containing, for example, hydrochloric acid or nitric acid.
One or two or more methods can be used together to roughen the support.

The electrolytic surface roughening treatment is described, for example, in JP-B-48-28123 and British Patent No. 896,563.
And in the specification of Japanese Patent Application Laid-Open No. 53-67507, these methods can be used in the present invention.

The voltage applied in the electrochemical graining is preferably 1 to 50 volts, more preferably 5 to 30 volts. The current density is preferably from 10 to 200 A / dm ^2, more preferably 20 to 150 A / dm ^2. The quantity of electricity is 100 to 2000 coulomb / dm ² , preferably 2
00 to 1500 coulomb / dm ² , more preferably 20
0 to 1000 is the Coulomb / dm ^2. The temperature is between 10 and
50 ° C is preferable, and 15 to 45 ° C is more preferable. The concentration of hydrochloric acid or nitric acid is preferably 0.1 to 5% by weight.

To the electrolytic solution, if necessary, nitrates, chlorides, amines, aldehydes, phosphoric acid, chromic acid, boric acid, acetic acid, oxalic acid and the like can be added.

When two or more roughening treatments are combined, it is preferable to perform a chemical etching treatment immersed in an aqueous acid or alkali solution between each treatment. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like, and examples of the base include sodium hydroxide, potassium hydroxide, and the like. Among these, it is preferable to use an aqueous alkali solution. 40 to 100 ° C. using a 0.05 to 40% by weight aqueous solution of these acids or alkalis
A method of treating at a liquid temperature of 5 to 300 seconds can be applied.

When the above treatment is carried out by immersion treatment with an aqueous alkali solution, smut is formed on the surface of the support. It is preferable to immerse in a mixed acid and perform desmut treatment.

The roughened aluminum support can then be subjected to an anodic oxidation treatment. As the electrolyte used for the anodic oxidation treatment, any electrolyte can be used as long as it forms a porous oxide film. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, sulfamic acid, benzenesulfonic acid, and the like, or two or more kinds thereof, are used. Is used. Anodizing treatment conditions vary depending on the electrolytic solution used, and thus cannot be specified unconditionally. However, in general, the concentration of the electrolytic solution is 1 to 80% by weight, the temperature is 5 to 70 ° C,
Appropriate current density is 1 to 60 A / dm ² , voltage is 1 to 100 V, and electrolysis time is 10 seconds to 5 minutes. Preferred is a sulfuric acid method, which is usually treated with a direct current, but an alternating current can also be used. The concentration of sulfuric acid is 10 to 50% by weight, the temperature is 20 to 50 ° C, and the current density is 20 to ² at a current density of 1 to 20 A / dm ² .
Preferably, the electrolytic treatment is performed for 50 seconds. Preferably, the electrolyte contains aluminum ions.

The anodized aluminum support is then subjected to a sealing treatment. The sealing treatment can be performed using a known method such as hot water treatment, boiling water treatment, steam treatment, sodium silicate treatment, dichromate aqueous solution treatment, nitrite treatment, and ammonium acetate treatment.

The aluminum support having been subjected to the sealing treatment includes:
Next, a hydrophilic layer may be provided. To form the hydrophilic layer,
The alkali metal silicate described in U.S. Pat. No. 3,181,461, the hydrophilic cellulose described in U.S. Pat. No. 1,860,426, Japanese Patent Publication No. 6-94234, and Japanese Patent Publication No. 6-2436. Amino acids and salts thereof described in JP-A-60-232998, amines having a hydroxyl group and salts thereof described in JP-A-60-232998, JP-A-62-194
No. 94, a phosphate described in JP-A-59-101651.
For example, a polymer compound containing a monomer unit having a sulfo group described in Japanese Patent Application Laid-Open No. H10-260, etc. can be used.

Further, in order to prevent scratches on the photosensitive layer when the photosensitive lithographic printing plates are stacked, and to prevent elution of the aluminum component into the developing solution during development, Japanese Patent Application Laid-Open No.
JP-A-151136, JP-A-57-63293, JP-A-60-73538, JP-A-61-67863, JP-A-6-35174, etc., in which a protective layer is provided on the back surface of the support. It can be performed.

The photosensitive composition used in the photosensitive layer of the photosensitive lithographic printing plate to be treated with the solution containing the polymer of the present invention is not particularly limited as long as it is used as the photosensitive layer of the photosensitive lithographic printing plate. Good. Examples of such a photosensitive composition include the following various compositions.

Photosensitive composition containing o-quinonediazide compound as photosensitive component The photosensitive composition containing o-quinonediazide compound as photosensitive component uses both o-quinonediazide compound and alkali-soluble resin. The o-quinonediazide compound is a compound having an o-quinonediazide group in a molecule, and is not particularly limited. For example, a polycondensation resin having an o-quinonediazide group (o-naphthoquinonediazidesulfonic acid and phenols and aldehydes) Or an ester compound with a polycondensation resin with a ketone). Examples of the phenol in the polycondensation resin with the phenol and aldehyde or ketone include, for example, phenol, o
Monohydric phenols such as-, m-, p-cresol, 3,5-xylenol, carvacrol and thymol; dihydric phenols such as catechol, resorcin and hydroquinone; and trihydric phenols such as pyrogallol and phloroglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde furfural and the like. Preferred among these are formaldehyde and benzaldehyde. Examples of the ketone include acetone, methyl ethyl ketone and the like. Specific examples of polycondensation resins with phenols and aldehydes or ketones include phenol-formaldehyde resin, m-cresol-formaldehyde resin, m- and p-mixed cresol-formaldehyde resin, resorcinol-benzaldehyde resin, pyrogallol-acetone Resins.

In the above-mentioned o-naphthoquinonediazide compound, the condensation rate of o-naphthoquinonediazidosulfonic acid to OH groups of phenols (reaction rate per OH group) is preferably 15 to 80%, more preferably 20 to 80%.
45%. Examples of the o-quinonediazide compound used in the present invention include the following compounds described in JP-A-58-43451. Known 1,2-quinonediazide compounds such as 1,2-benzoquinonediazidesulfonic acid ester, 1,2-naphthoquinonediazidosulfonic acid ester, 1,2-benzoquinonediazidosulfonic acid amide, and 1,2-naphthoquinonediazidosulfonic acid amide; More specifically, J.I. "Light by Kosar"
t-Sensitive Systems "(1965)
Years) pp. 339-352, John Willey &
Sons (New York) and W.S. S. De F
Orest, "Photoresist," Vol. 50 (1
975), McGraw Hill (New Yo)
rk), 1,2-benzoquinonediazido-4-sulfonic acid phenyl ester, 1,2,1 ',
2'-di- (benzoquinonediazide-4-sulfonyl)
-Dihydroxybiphenyl, 1,2-benzoquinonediazide-4- (N-ethyl-N-β-naphthyl) -sulfonamide, 1,2-naphthoquinonediazide-5-sulfonic acid cyclohexyl ester, 1- (1,2-naphthoquinonediazide- 5-sulfonyl) -3,5-dimethylpyrazole, 1,2-naphthoquinonediazide-5-sulfonic acid-4'-hydroxydiphenyl-4'-azo-β-
Naphthol ester, N, N-di- (1,2-naphthoquinonediazide-5-sulfonyl) -aniline, 2'-
(1,2-naphthoquinonediazide-5-sulfonyloxy) -1-hydroxyanthraquinone, 1,2-naphthoquinonediazide-5-sulfonic acid-2,4-dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-sulfonic acid Condensate of 2,2,3,4-trihydroxybenzophenone ester, 2 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mol of 4,4'-diaminobenzophenone, 1,2-naphthoquinonediazide-5 2 mol of sulfonic acid chloride and 4,4 '
Condensate with 1 mol of dihydroxy-1,1'-diphenylsulfonic acid, condensate of 1 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride with 1 mol of purprogalin, 1,2-naphthoquinonediazide-5 1,2-naphthoquinonediazide compounds such as (N-dihydroabiethyl) sulfonamide can be exemplified. Also,
JP-B-37-1953, JP-B-37-3627, JP-B-37
No. -13109, No. 40-26126, No. 40-38
No. 01, No. 45-5604, No. 45-27345,
1,2-quinonediazide compounds described in JP-A-51-13013, JP-A-48-96575, JP-A-48-63802, and JP-A-48-63803 can also be used. Among the o-quinonediazide compounds, 1,2-benzoquinonediazide sulfonyl chloride or 1,2-
An o-quinonediazide ester compound obtained by reacting naphthoquinonediazidosulfonyl chloride with a pyrogallol-acetone condensation resin or 2,3,4-trihydroxybenzophenone is particularly preferred. The above compounds may be used alone or in combination of two or more. The proportion in the photosensitive composition is preferably from 5 to 60% by weight, and particularly preferably from 10 to 50% by weight.

Photosensitive composition containing diazo compound as photosensitive component The diazo compound used in the photosensitive composition containing the diazo compound as a photosensitive component is, for example, preferably a condensate of an aromatic diazonium salt with formaldehyde or acetaldehyde. Is a diazo resin represented by Particularly preferably, a salt of a condensate of p-diazophenylamine with formaldehyde or acetaldehyde, for example, the reaction product of the above condensate with hexafluoroborate, tetrafluoroborate, perchlorate or periodate And diazo resin organic salts which are reaction products of the condensate and sulfonic acids as described in US Pat. No. 3,300,309. Furthermore, diazo resins are preferably used with binders. As the binder, various polymer compounds can be used.
Monomers having an aromatic hydroxyl group as described in No. 13, such as N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide, o-, m-, or p- Hydroxystyrene,
Copolymers of o-, m- or p-hydroxyphenyl methacrylate and the like with other monomers, U.S. Pat.
Polymers containing a hydroxyethyl acrylate unit or a hydroxyethyl methacrylate unit as a main repeating unit, natural resins such as shellac and rosin, polyvinyl alcohol as described in US Pat. No. 3,276,
Cellulol derivatives such as linear polyurethane resins, phthalated resins of polyvinyl alcohol, epoxy resins condensed from bisphenol A and epichlorohydrin, cellulose acetate and cellulose acetate phthalate as described in US Pat. No. 3,751,257. Is included.

Photo-Crosslinking Photosensitive Composition The photosensitive component in the photocrosslinking photosensitive composition comprises a photosensitive resin having an unsaturated double bond in the molecule. For example, US Pat. No. 3,030,208 No. 3,435,23
No. 7, No. 3,622,320, etc., as a photosensitive group in the polymer main chain, -CH = CH-CO
And a polyvinyl cinnamate having a photosensitive group in a side chain of the polymer.

Photopolymerizable Photosensitive Composition The photopolymerizable photosensitive composition is a photopolymerizable composition containing an addition polymerizable unsaturated compound, and is a monomer having a double bond or a double bond. Representative examples of such a composition include, for example, U.S. Pat. Nos. 2,760,863 and 2,795.
No. 1,504 and the like.

For example, a composition containing methyl methacrylate, a composition containing methyl methacrylate and polymethyl methacrylate, a composition containing methyl methacrylate, polymethyl methacrylate and a polyethylene glycol methacrylate monomer, methyl methacrylate, alkyd resin And a photopolymerizable composition such as a composition containing polyethylene glycol dimethacrylate monomer.

The photopolymerizable photosensitive composition contains a photopolymerization initiator generally known in the art (for example, a benzoin derivative such as benzoin methyl ether, a benzophenone derivative such as benzophenone, a thioxanthone derivative,
Anthraquinone derivatives, acridone derivatives, etc.).

Each of the photosensitive compositions may contain an alkali-soluble resin as a binder. The alkali-soluble resin is not particularly restricted but includes, for example, a novolak resin, a vinyl polymer having a phenolic hydroxyl group, and a condensation resin of a polyhydric phenol and an aldehyde or ketone described in JP-A-55-57841. be able to. Novolak resins that can be used include, for example, phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolymer resin described in JP-A-55-57841, and p-substituted phenol described in JP-A-55-127553. And phenol or cresol and formaldehyde. The molecular weight (polystyrene standard) of the novolak resin is preferably such that the number average molecular weight Mn is 3.00 × 10 ^{2 to} 7.50 × 10 ³ and the weight average molecular weight Mw is 1.00 × 10 ^{3 to} 3.00 × 10 ⁴ . Preferably, Mn is 5.00 × 10 ^{2 to} 4.00 × 10 ³ , M
w is 3.00 × 10 ^{3 to} 2.00 × 10 ⁴ . The above novolak resins may be used alone or in combination of two or more. The novolak resin is preferably contained in the photosensitive composition in an amount of 5 to 95% by weight. The vinyl polymer having a phenolic hydroxyl group is a copolymer having a unit having the phenolic hydroxyl group in a molecular structure, and a structural unit represented by the following general formulas [1] to [5]: Polymers containing at least one are preferred.

[0087]

Embedded image

In the general formulas [1] to [5], R ₁ and R ₂ each represent a hydrogen atom, an alkyl group or a carboxyl group, preferably a hydrogen atom. R ₃ represents a hydrogen atom, a halogen atom or an alkyl group, preferably a hydrogen atom, an alkyl group such as a methyl group or an ethyl group. R ₄ represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and is preferably a hydrogen atom. A connects a nitrogen atom or an oxygen atom with an aromatic carbon atom,
Represents an alkylene group which may have a substituent, and m represents 0 to 1
Represents an integer of 0, and B represents a phenylene group which may have a substituent or a naphthylene group which may have a substituent. The vinyl polymer having a phenolic hydroxyl group used in the present invention preferably has a copolymer type structure having the structural units represented by the general formulas [1] to [5],
As monomers to be copolymerized, for example, ethylene, propylene, isobutylene, butadiene, ethylenically unsaturated olefins such as isoprene, for example, styrene, α-methylstyrene, p-methylstyrene, styrenes such as p-chlorostyrene, Acrylic acids such as methacrylic acid and the like; unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid and maleic anhydride; for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic acid Esters of α-methylene aliphatic monocarboxylic acids such as dodecyl, 2-chloroethyl acrylate, phenyl acrylate, benzyl methacrylate, α-methyl methacrylate, methyl methacrylate, ethyl methacrylate, ethyl ethacrylate, etc. Acryloni Nitriles such as ril and methacrylonitrile, for example, amides such as acrylamide and methacrylamide, for example, anilides such as acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide m-methoxyacrylanilide, for example, vinyl acetate and propionic acid Vinyl esters such as vinyl, vinyl butyrate and vinyl benzoate, for example, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether and β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, for example, 1-methyl-1 -Methoxyethylene, 1,
Ethylene derivatives such as 1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, 1-methyl-1-nitroethylene, for example, N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, There are N-vinyl monomers such as N-vinylpyrrolidene and N-vinylpyrrolidone. These monomers are present in the polymer compound in a structure in which the unsaturated double bond is cleaved. Of the above monomers, esters and nitriles of aliphatic monocarboxylic acids exhibit excellent performance and are preferred.

These monomers may be bonded to the polymer used in the present invention in either a block or random state. The vinyl polymer having a phenolic hydroxyl group is preferably contained in the photosensitive composition in an amount of 0.5 to 70% by weight. As the vinyl polymer having a phenolic hydroxyl group, the above polymers may be used alone or in combination of two or more. Further, it can be used in combination with another polymer compound or the like.

The photosensitive composition may contain the following additives in addition to the above.

(1) Acid: For example, JP-A-60-88942
And Japanese Patent Application No. 63-293107, and inorganic acids described in Chemical Society Handbook, New Edition, edited by The Chemical Society of Japan (Maruzen Publishing), pp. 92-158. Examples of organic acids include sulfonic acids such as p-toluenesulfonic acid, dodecylbenzenesensulfonic acid, mesitylenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, m-benzenedisulfonic acid, p-toluenesphinic acid, benzyl Sulfinic acids such as sulfinic acid and methanesulfinic acid, and phosphonic acids such as phenylphosphonic acid, methylphosphonic acid and chloromethylphosphonic acid, and aliphatic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, pentanoic acid, hexanoic acid, and heptanoic acid Alicyclic monocarboxylic acids such as monocarboxylic acid and cyclohexanecarboxylic acid, benzoic acid, o-,
m-, p-hydroxybenzoic acid, o-, m-, p-methoxybenzoic acid, o-, m-, p-methylbenzoic acid, 3,
Examples thereof include aromatic monocarboxylic acids such as 5-dihydroxybenzoic acid, phloroglysin carboxylic acid, gallic acid, and 3,5-dimethylbenzoic acid. Also, saturated or unsaturated aliphatic dicarboxylic acids such as malonic acid, methylmalonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, itaconic acid, and malic acid; Phthalic acid, 1,1-cyclobutanedicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,
1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid, phthalic acid, isophthalic acid,
Examples thereof include aromatic dicarboxylic acids such as terephthalic acid. More preferred among the organic acids are p-toluenesulfonic acid, dodecylbenzenesulfonic acid, mesitylenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, m-benzenedisulfonic acid,
1,2-cyclohexanedicarboxylic acid and syringic acid.

Examples of the inorganic acid include nitric acid, sulfuric acid, hydrochloric acid, silicic acid, phosphoric acid and the like, more preferably sulfuric acid and phosphoric acid.

When the acid anhydride is used, the type of the acid anhydride is also arbitrary, and those derived from aliphatic / aromatic monocarboxylic acids such as acetic anhydride, propionic anhydride and benzoic anhydride, succinic anhydride, Examples thereof include those derived from aliphatic / aromatic dicarboxylic acids such as maleic anhydride, glutaric anhydride, and phthalic anhydride. Preferred are glutaric anhydride and phthalic anhydride. The content of these acids is generally from 0.05 to 5% by weight, preferably from 0.1 to 3% by weight, based on the total solid content of the entire photosensitive composition. These compounds may be used alone or in combination of two or more.

(2) Surfactant: Surfactants include:
Examples include amphoteric surfactants, anionic surfactants, cationic surfactants, nonionic surfactants, and fluorinated surfactants. Examples of the amphoteric surfactant include lauryl dimethylamine oxide, lauryl carboxymethyl hydroxyethyl, imidazolinium betaine and the like. Examples of anionic surfactants include fatty acid salts, alkyl sulfate salts, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether disulfonates, alkyl phosphates, and polyoxyethylene alkyl sulfates. , Polyoxyethylene alkyl allyl sulfate, naphthalene sulfonic acid formalin condensate,
And polyoxyethylene alkyl phosphates.
Examples of the cationic surfactant include an alkylamine salt and a quaternary surfactant.
Secondary ammonium salts, alkyl betaines and the like. As nonionic surfactants, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether,
Polyoxyethylene derivative, oxyethylene / oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester,
There are polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, alkylalkanolamide and the like. Examples of the fluorinated surfactant include acrylates, methacrylates and copolymers of (polyoxyalkylene) acrylate or (polyoxyalkylene) methacrylate containing a fluoroaliphatic group, JP-A-62-170950, JP-A-62-226.
No. 143 and U.S. Pat. No. 3,787,351. For example, Mega Fuck F-17
1,173,177, Defenser MCF300,31
2,313 (manufactured by Dainippon Ink and Chemicals, Inc.) and Modiper F-100, 102, 110 (manufactured by NOF Corporation). These compounds can be used alone or in combination of two or more. The proportion occupying in these photosensitive compositions is preferably from 0.01 to 10% by weight, more preferably from 0.01 to 5% by weight.

(3) Visible paint: Examples of the compound that generates an acid or a free radical upon exposure include a halomethyloxadiazole compound and a halomethyl-s-triazine compound. A halomethyloxadiazole compound is a compound having a halomethyl group, preferably a trichloromethyl group, on the oxadiazole ring. These compounds are known, for example, JP-B-57-6096 and JP-B-57-6096.
JP-A-1-51788, JP-B-1-28369, JP-A-6
No. 0-138439, No. 60-177340, No. 60
-24049. Further, a halomethyl-s-triazine compound is a compound having one or more halomethyl groups, preferably a trichloromethyl group, in an s-triazine ring. These compounds can be used alone or in combination of two or more. The proportion in these photosensitive compositions is preferably 0.01 to 30% by weight, more preferably 0.1 to 10% by weight, and particularly preferably 0.2 to 3% by weight.

(4) Dye: As the dye, those which react with free radicals or acids to change the color tone can be preferably used. Here, the term “color tone changes” includes any of a change from colorless to colored and a change from colored to colorless or different colored tones. Preferred dyes are those that form a salt with an acid to change the color tone. For example, Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue # 603 (manufactured by Orient Chemical Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Sangoku Chemical Co., Ltd.), crystal violet, brilliant green, ethyl violet, methyl violet, methyl green , Erythrosin B,
Basic fuchsin, malachite green, oil red, m-cresol purple, rhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, triphenylmethane series, diphenylmethane series, oxazine series represented by cyano-p-diethylaminophenylacetanilide, etc. , Xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes are examples of color changing agents that change from colored to colorless or different colored tones. On the other hand, as a color changing agent that changes from colorless to colored, leuco dye, and, for example, triphenylamine, diphenylamine, o-chloroaniline,
1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p′-bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p, p ′, p ″ -tris-dimethylaminotriphenylmethane, p, p'-bis-dimethylaminodiphenylmethylimine, p, p ', p "-triamino-o-
Methyltriphenylmethane, p, p'-bis-dimethylaminodiphenyl-4-anilinonaphthylmethane, p,
Primary or secondary arylamine dyes represented by p ', p "-triaminotriphenylmethane. These compounds can be used alone or in combination of two or more. The proportion in the photosensitive composition is preferably from 0.01 to 10% by weight, more preferably from 0.02 to 5% by weight, among which Victoria Pure Blue BOH or Oil Blue # 603 is particularly preferred. is there.

(5) Oil Sensitizers: Examples of those which improve the oil sensitivity of image areas include half-esterified products of styrene-maleic anhydride copolymers with alcohols described in JP-A-55-527, p- Novolak resins such as t-butylphenol-formaldehyde resin or partial esters of these resins with o-quinonediazide compounds, fluorine-based surfactants, p-hydroxystyrene 5
0% fatty acid ester and the like. These addition amounts are 0.01 to 30% by weight of the total solid content of the photosensitive composition.

(6) Matting agent: The purpose of the matting layer is to improve the vacuum adhesion between the image film and the photosensitive lithographic printing plate in contact exposure, thereby shortening the evacuation time and further reducing the exposure time due to poor adhesion. The purpose is to prevent the collapse of minute dots. Japanese Patent Application Laid-Open No.
A method of heat fusing powdered solid powder described in JP-A-12974; a method of spraying and drying polymer-containing water described in JP-A-58-182636;
There is a method of adding the compound described in JP-A-9739 into the photosensitive layer and simultaneously coating the same, and any method may be used. However, it is preferable that the mat layer itself is dissolved in the alkali developer or can be removed by this.

(7) Inclusion compound: JP-A-5-17333
An inclusion compound described in JP-A No. 3

The photosensitive lithographic printing plate is provided on the surface of the photosensitive layer with:
A mat layer can be provided in order to reduce the time for evacuation during contact exposure using a vacuum baking frame and prevent baking. Specifically, JP-A-50-125805,
A method of providing a mat layer as described in JP-B-57-6581 and JP-B-61-28986.
No. 62337, for example, a method of thermally fusing a solid powder.

The polymer of the present invention can be synthesized by various generally known methods. Examples of the synthesis using the acrylic monomer include the following methods.

Synthesis Example 1 In a 200-ml three-necked flask equipped with a stirrer, a condenser, and a dropping funnel, 5.3 g of the acrylic monomer C (n = 6), 3.9 g of methacrylic acid, and hydroxyethyl methacrylate were added. 2.0 g and 50 ml of N, N-dimethylformamide were added, and the mixture was stirred while being heated to 64 ° C. in a hot water bath. 0.25 g of α, α-azobisisobutyronitrile was added to the mixture, and the mixture was stirred for 5 hours under a nitrogen stream while maintaining the temperature at 64 ° C. After the completion of the reaction, this reaction product was added dropwise to 1 liter of hexane with stirring, stirred for 30 minutes, and then filtered and dried to obtain a white solid. The weight average molecular weight (based on polystyrene) of the polymer compound was measured by gel permeation chromatography and found to be 23,000. (Polymer A of the Present Invention) Synthesis Example 2 The monomer to be charged was an acrylic monomer G (n = 4)
4.9 g, 3.3 g of acrylic acid, and 1.5 g of N-methylolacrylamide were synthesized in the same manner as in Synthesis Example 1. The weight average molecular weight was 20,000. (Polymer B of the Present Invention) Synthesis Example 3 The monomer to be charged was an acrylic monomer I (n = 8)
10.5 g, 3.3 g of acrylic acid, and 2.0 g of hydroxyethyl methacrylate were synthesized in the same manner as in Synthesis Example 1. The weight average molecular weight was 35,000. (Polymer C of the Present Invention) Comparative Polymer Synthesis Example Synthesis was performed in the same manner as in Synthesis Example 1 except that the monomers to be charged were 3.8 g of acrylic acid and 3.0 g of hydroxyethyl methacrylate. The weight average molecular weight was 15,000.
(Comparative polymer A)

[0103]

EXAMPLE 1 An aluminum plate (material 1050, tempered H16) having a thickness of 0.3 mm was immersed in a 10% aqueous sodium hydroxide solution maintained at 85 ° C., and subjected to a degreasing treatment for 30 seconds. Washed with water. The degreased aluminum plate was immersed in a 10% sulfuric acid aqueous solution maintained at 25 ° C. for 1 minute, subjected to desmut treatment, and washed with water. Then, the aluminum plate was added 1.0%
In hydrochloric acid aqueous solution at a temperature of 30 ° C. and a current density of 60 A
/ Dm ² and 50 Hz sine wave AC current
Electrolytic surface roughening was performed for seconds. Then, 10% kept at 60 ° C
Immerse in sodium hydroxide aqueous solution for 10 seconds, then
Immersed in a 10% sulfuric acid aqueous solution maintained at 5 ° C. for 20 seconds,
After the desmut treatment, it was washed with water. Subsequently, in a 20% sulfuric acid aqueous solution at a temperature of 35 ° C. and a current density of 3 A / dm ² ,
Anodizing treatment was performed for 0 seconds. After that, concentration 0.05w
t. %, 15% in aqueous solution of sodium oxalate at 95 ° C
It was immersed for 2 seconds to perform a first hydrophilic treatment. After washing with water for 10 seconds running water, the concentration the molar ratio of SiO ₂ / Na ₂ O with sodium silicate 3.7 0.2 wt. %, Temperature 30 ℃
For 30 seconds to perform a second hydrophilic treatment. After washing with water for 10 seconds, it was dried at 80 ° C. for 5 minutes to obtain an aluminum support 1.

Next, a photosensitive composition coating solution having the following composition was applied using a wire bar and dried at 80 ° C. for 2 minutes to obtain a photosensitive lithographic printing plate. At this time, the photosensitive composition coating solution was adjusted to have a dry weight of 2.0 g / m ² .

Photosensitive Composition Novolak resin (Mole ratio of phenol / m-cresol / p-cresol: 10/54/36 and Mw: 4000) 6.70 g Pyrogallol acetone resin (Mw: 3000) and o-naphthoquinonediazide Condensate of 5-sulfonyl chloride (esterification rate 30%) 1.50 g Hydroxypropyl-β-cyclodextrin (Japan Food Processing Co., Ltd.) 0.15 g Polyethylene glycol # 2000 0.20 g Victoria Pure Blue BOH (Hodogaya Chemical ( 0.08 g 2,4-bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Co., Ltd.) 0.03 g cis-1, 2-cyclohexanedicarboxylic acid 0.02 g Methyl cellosolve 100 m Exposure, respectively developing the resulting photosensitive lithographic printing plate, a light source 4
Using a kW metal halide lamp and exposure with a Kodak Step Tablet at an exposure equivalent to 4-step clear, the following developing solution was charged into an automatic developing machine PSZ-910II manufactured by Konica Corporation, and the following printing plate was placed in the finishing tank. A protective agent was charged and development was performed at a development temperature of 30 ° C. Evaluation method of stop dirt The obtained lithographic printing plate was used as a printing machine (DAI manufactured by Mitsubishi Heavy Industries, Ltd.).
YA1F-1) and coated with dampening solution (etch solution SG-51 concentration 1.5%, manufactured by Tokyo Ink Co., Ltd.) and ink (High Plus M Red manufactured by Toyo Ink Mfg. Co., Ltd.). The printing press was stopped once after 5,000 sheets were printed, left for 1 hour, and printing was started, and the generated fine spot-like stains were evaluated by the number within 100 cm ² .

Developer (Invention) Potassium A silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 parts by weight Potassium hydroxide 86 parts by weight Salicylic acid 18 parts by weight Polymer A of the present invention 1 part by weight betaoxy Naphthoic acid 18 parts by weight Water 1513 parts by weight Plate surface protective agent Modified dextrin (Penone JE-66, manufactured by Nisseki Chemical Co., Ltd.) 10.0 parts by weight Carboxymethyl cellulose sodium salt 0.45 parts by weight Phosphoric acid (85%) 0.25 Parts by weight sodium di (2-ethylhexyl) sulfosuccinate 0.14 parts by weight polyoxyethylene nonyl phenyl ether 0.1 parts by weight p-hydroxyethyl benzoate 0.05 parts by weight water 90.0 parts by weight Example 2 The same experiment as in Example 1 was performed except that the developing solution was changed.

Example 3 The same experiment as in Example 1 was carried out except that the developing solution was changed to the following developing solution.

Comparative Example 1 The same experiment as in Example 1 was performed except that the developing solution was changed to the following developing solution.

Comparative Example 2 The same experiment as in Example 1 was performed except that the developing solution was changed to the following developing solution.

Comparative Example 3 The same experiment as in Example 1 was performed except that the developing solution was changed to the following developing solution.

Developer (Invention) Potassium A silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 parts by weight Potassium hydroxide 78 parts by weight Beta-oxynaphthoic acid 17 parts by weight Polymer B of the present invention 1 part by weight Part Perex NB-L (manufactured by Kao Corporation) 17 parts by weight Water 1521 parts by weight Developing solution (the present invention) Potassium A silicate (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 parts by weight Potassium hydroxide 92 parts by weight Parts Polymer C of the present invention 1 part by weight pt-benzoic acid 17 parts by weight EDTA 17 parts by weight Water 1506 parts by weight Developer A Potassium silicate (SiO ₂ : 26% by weight, K ₂ O: 13% by weight) 100 parts by weight Water Potassium oxide 86 parts by weight Comparative polymer A 1 part by weight Salicylic acid 18 parts by weight Beta-oxynaphthoic acid 18 parts by weight Water 1513 parts by weight Developer A potassium silicate Arm _{(SiO 2: 26wt%, K} 2 O: 13wt%) 100 parts by weight of potassium hydroxide 78 parts by weight of polyoxyethylene alkyl ether (Emulgen 147; manufactured by Kao Corp.) 1 part by weight of beta-oxy naphthoic acid 17 parts by weight Pelex NB-L (manufactured by Kao Corporation) 17 parts by weight Water 1521 parts by weight Developer A Potassium silicate A (SiO ₂ : 26 wt%, K ₂ O: 13 wt%) 100 parts by weight Potassium hydroxide 92 parts by weight pt-benzoic acid 17 Parts by weight EDTA 17 parts by weight Water 1506 parts by weight Example 4 The same experiment as in Example 1 was carried out except that the developing solution was changed to the above developing solution, and the plate surface protecting agent was changed to the following plate surface protecting agent.

Example 5 The same experiment as in Example 1 was carried out except that the developing solution was changed to the above-mentioned developing solution, and the plate surface protecting agent was changed to the following plate surface protecting agent.

Comparative Example 4 The same experiment as in Example 1 was carried out except that the developing solution was changed to the above-mentioned developing solution and the plate surface protecting agent was changed to the following plate surface protecting agent.

Comparative Example 5 The same experiment as in Example 1 was carried out except that the developing solution was changed to the above-mentioned developing solution and the plate surface protecting agent was changed to the following plate surface protecting agent.

Plate surface protective agent (the present invention) Modified dextrin (Penone JE-66, manufactured by Nisse Chemical Corporation) 10.0 parts by weight Carboxymethyl cellulose sodium salt 0.45 parts by weight Phosphoric acid (85%) 0.25 parts by weight Polymer C of the present invention 0.3 parts by weight Sodium di (2-ethylhexyl) sulfosuccinate 0.14 parts by weight 0.1 parts by weight sodium dodecylbenzenesulfonate 0.05 parts by weight p-hydroxyethylbenzoate 0.05 parts by weight Water 90.0 parts by weight Part Plate surface protective agent (this invention) White dextrin 5.0 parts by weight Hydroxypropyl etherified starch 10.0 parts by weight Gum arabic 1.0 parts by weight Polymer B of the present invention 0.4 parts by weight First ammonium phosphate 0.1 Parts by weight sodium dilauryl succinate 0.15 parts by weight sodium dodecylbenzenesulfonate 0.5 parts by weight Parts Ethylene glycol 1.0 part by weight EDTA 0.005 part by weight Dehydroacetic acid 0.005 part by weight Water 100.0 parts by weight Plate surface protective agent 5.0 parts by weight White dextrin 5.0 parts by weight Hydroxypropyl etherified starch 10.0 parts by weight Gum arabic 1 0.0 part by weight Comparative polymer A 0.4 part by weight Ammonium phosphate 0.1 part by weight Sodium dilauryl succinate 0.15 part by weight Sodium dodecylbenzenesulfonate 0.5 part by weight Ethylene glycol 1.0 part by weight EDTA 0.005 parts by weight Dehydroacetic acid 0.005 parts by weight Water 100.0 parts by weight Example 6 A photosensitive lithographic printing plate prepared in the same manner as in Example 1 was not exposed to light but was subjected to an automatic developing machine manufactured by Konica Corporation. PSZ-910II
And the finishing solution was charged into the finishing tank, and the plate surface protective agent was charged into the finishing tank. The lithographic printing plate thus obtained as an entire image portion was prepared by using a correction solution having the following composition, and was adjusted to 20 cm × 2.
The image area was removed with a size of 0 cm and washed with water. Thereafter, SGQ-3 manufactured by Konica Corporation was applied to the plate surface, and the stop stain was evaluated in the same manner as in Example 1.

Correction Solution (Invention) γ-butyrolactone 71.0 parts by weight Pure water 10.0 parts by weight Acid rhodamine B 0.02 parts by weight Polymer A of the present invention 0.3 parts by weight Polyoxyethylene polyoxypropylene ether 7.0 parts by weight Hydroxypropyl methylcellulose 2.0 parts by weight Powdered silicon dioxide 9.0 parts by weight Example 7 The same experiment as in Example 6 was performed except that the correction liquid was changed to the following correction liquid.

Example 8 The same experiment as in Example 6 was performed, except that the correction liquid was changed to the following correction liquid.

Comparative Example 6 The same experiment as in Example 6 was performed, except that the correction liquid was changed to the following correction liquid.

Comparative Example 7 The same experiment as in Example 6 was performed except that the correction liquid was changed to the following correction liquid.

Comparative Example 8 The same experiment as in Example 6 was performed, except that the correction liquid was changed to the following correction liquid.

Correction liquid (the present invention) γ-butyrolactone 40.0 parts by weight Cyclohexanone 21.0 parts by weight Xylene 10.0 parts by weight Pure water 10.0 parts by weight Polymer B of the present invention 0.5 parts by weight Crystal violet 0 0.02 parts by weight Polyoxyethylene polyoxypropylene ether 7.0 parts by weight Hydroxypropyl methylcellulose 2.0 parts by weight Powdered silicon dioxide 9.0 parts by weight Correction solution (the present invention) Benzyl alcohol 13.0 parts by weight Cyclohexanone 36.0 parts by weight Part Polymer C of the present invention 0.4 part by weight Dimethylformamide 14.0 parts by weight Xylene 6.0 parts by weight Pure water 10.0 parts by weight Phosphoric acid (85%) 1.0 part by weight Acid rhodamine B 0.002 parts by weight Parts polyoxyethylene polyoxypropylene ether 7.0 parts by weight hydroxypropyl 6.0 parts by weight of tilcellulose 6.0 parts by weight of powdered silicon dioxide Correction liquid 71.0 parts by weight of γ-butyrolactone 10.0 parts by weight of pure water 0.02 parts by weight of acid rhodamine B Polyoxyethylene polyoxypropylene ether 8.0 Parts by weight Hydroxypropyl methylcellulose 2.0 parts by weight Powdered silicon dioxide 9.0 parts by weight Correction liquid γ-butyrolactone 40.0 parts by weight Cyclohexanone 21.0 parts by weight Xylene 10.0 parts by weight Comparative polymer A 0.5 parts by weight Pure Water 10.0 parts by weight Crystal violet 0.02 parts by weight Polyoxyethylene polyoxypropylene ether 7.0 parts by weight Hydroxypropyl methyl cellulose 2.0 parts by weight Powdered silicon dioxide 9.0 parts by weight Correction liquid Benzyl alcohol 13.0 parts by weight Cyclohexanone 36.0 parts by weight Tilformamide 14.0 parts by weight Xylene 6.0 parts by weight Pure water 10.0 parts by weight Phosphoric acid (85%) 1.0 part by weight Acid rhodamine B 0.002 parts by weight Polyoxyethylene polyoxypropylene ether 8.0 parts by weight Part Hydroxypropyl methylcellulose 6.0 parts by weight Powdered silicon dioxide 6.0 parts by weight The above evaluation results are shown in Table 1 below.

[0122]

[Table 1]

[0123]

According to the present invention, when printing is performed using a lithographic printing plate prepared from a photosensitive lithographic printing plate, after the printing press has been stopped for a while due to consideration, break, etc., it occurs in the non-image area when printing is resumed. There is provided a technique for preventing minute spot-like stains (stop stains).

Claims (5)

[Claims] 1. A polymer having a polyoxyethylene group having 2 or more repeating units in a side chain or a polymer having a polyoxypropylene group having 2 or more repeating units in a side chain during or after development processing. A photosensitive lithographic printing plate, characterized in that the lithographic printing plate has been treated with a solution. 2. A polymer having a polyoxyethylene group having a repeating unit of 2 or more in a side chain or a polyoxypropylene group having a repeating unit of 2 or more in a side chain during or after development of a photosensitive lithographic printing plate. A method for treating a photosensitive lithographic printing plate, comprising treating with a solution containing a polymer having the formula: 3. A photosensitive lithographic plate comprising a polymer having a polyoxyethylene group having two or more repeating units in a side chain or a polymer having a polyoxypropylene group having two or more repeating units in a side chain. Printing plate developer. 4. A photosensitive lithographic plate comprising a polymer having a polyoxyethylene group having two or more repeating units in a side chain or a polymer having a polyoxypropylene group having two or more repeating units in a side chain. Correction solution for printing plates. 5. A photosensitive composition comprising a polymer having a polyoxyethylene group having two or more repeating units in a side chain or a polymer having a polyoxypropylene group having two or more repeating units in a side chain. Plate surface protective agent for lithographic printing plates.