JP2684249B2 - 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.

[0002]

2. Description of the Related Art In general, a photosensitive printing plate is prepared by coating a photosensitive composition on a support such as an aluminum plate and irradiating an actinic ray such as ultraviolet rays through a negative image or the like to polymerize the irradiated portion. Crosslink and insolubilize in the developing solution, elute the non-irradiated portion of the light into the developing solution, and separate each portion of the image portion that repels water to receive the oil-based ink and the non-image portion that receives water to repel the oil-based ink. It is obtained by forming an image part.

In this case, the photosensitive composition includes:
Diazo resins such as condensates of p-diazodiphenylamine and formaldehyde have been widely used. Further, the aluminum support is desirably subjected to an appropriate hydrophilic treatment, for example, after roughening by, for example, nitric acid or hydrochloric acid electrolytic graining, anodizing in an acid such as sulfuric acid or phosphoric acid to form an oxide film on the aluminum surface. Supports provided with have been widely used.

On the other hand, when developing a photosensitive lithographic printing plate using these diazo resins after exposure, examples of aqueous alkaline developer compositions used include, for example, JP-A-51-774.
No. 01, a developer composition comprising benzyl alcohol, an anionic surfactant, an alkali agent and water, benzyl alcohol, an anionic surfactant described in JP-A-53-44202, A developer composition comprising an aqueous solution containing a water-soluble sulfite;
155355, a developer composition containing an organic solvent having an solubility in water of 10% by weight or less at room temperature, an alkali agent and water, and the like.

All of these contain an organic substance such as an organic solvent and a surfactant in the developer composition. However, organic solvents are generally toxic and odorous, have a risk of fire, and have many disadvantages such as being subject to BOD regulations in waste liquids, and are expensive. Attempts to develop a photosensitive lithographic printing plate using a diazo resin with a developer composition substantially free of these organic solvents are described in JP-A-57-192952 and JP-A-58-27141. ing.

However, since the developing solutions described above are strong alkalis having a pH of 12 or more, they have a strong corrosive action, and particularly easily attack the anodic oxide film. That is, a part of the anodic oxide film on the aluminum surface is eluted as aluminate ions into these developers. Therefore, when a large amount of a lithographic printing plate is subjected to development processing with these developing solutions, the concentration of aluminate ions in the developing solutions increases. When such a developing solution becomes thick due to the evaporation of water, the undissolved aluminate is deposited on the bottom of the developing bath, and dust and sludge are generated. Dust and sludge gradually solidify and clog the spray or pump of the automatic developing machine, and dust that has floated in the developer reattaches to the non-image area of the lithographic printing plate and becomes dirty. Therefore, these developers have a drawback that a large amount of lithographic printing plates cannot be developed.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lithographic printing plate having a photosensitive layer containing a diazo resin, which is developed with an aqueous alkaline developer containing substantially no organic solvent. An object of the present invention is to provide a method capable of developing a large amount of a photosensitive lithographic printing plate in a method for producing a printing plate.

[0008]

Means for Solving the Problems As a result of intensive investigations by the present inventors in order to achieve the above-mentioned object, as a result, a hydrochloric acid electrolytic surface-roughened surface was subjected to direct current with a current density of 8 to 25 A / dm ² in a sulfuric acid bath. The inventors have found that these objects can be achieved by a photosensitive lithographic printing plate using an anodized aluminum plate as a support, and arrived at the present invention.

The reason why the photosensitive lithographic printing plate using the above aluminum support is not easily attacked by strong alkali is not clear, but the surface subjected to hydrochloric acid electrolytic surface roughening treatment is 8 to 25 A / dm.
^It is thought that anodizing at a current density of ² produces a dense film with few defects. That is, in the present invention, the surface subjected to the electrolytic surface roughening treatment with hydrochloric acid is 8 to 25 A /
Image a photosensitive lithographic printing plate obtained by coating a photosensitive layer containing a diazo resin and a lipophilic polymer on an aluminum support anodized in a sulfuric acid bath with a direct current of a current density of dm ^2. After the exposure, it is developed with an alkaline aqueous solution having a pH of 12 or more and substantially containing no organic solvent to produce a lithographic printing plate, which is a method for producing a lithographic printing plate.

Hereinafter, the present invention will be described in detail. The support used in the present invention is an aluminum plate, preferably 1S aluminum, and more preferably aluminum containing 0.015 to 0.03% of copper. The aluminum plate is preferably etched by first immersing the aluminum plate in an aqueous solution of 1 to 30% sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate or the like at a temperature of 20 to 80 ° C. for 5 to 250 seconds. .

Then, it is immersed in an aqueous solution of 10 to 30% nitric acid or sulfuric acid at a temperature of 20 to 70 ° C. for 5 to 250 seconds to carry out neutralization and smut removal after alkali etching. After cleaning the surface of the aluminum plate, electrolytic surface roughening treatment is performed. In the present invention, the concentration of hydrochloric acid in the electrolytic solution used for the electrolytic surface roughening treatment is preferably in the range of 0.01 to 3% by weight, more preferably 0.05 to 2.5% by weight.

If necessary, the electrolytic solution contains a corrosion inhibitor (or a stabilizer) such as nitrates, chlorides, monoamines, diamines, aldehydes, phosphoric acid, chromic acid, boric acid, oxalic acid, and ammonium salts. Agent), a grain leveling agent, etc. can be added. The electrolytic solution may contain an appropriate amount (1 to 10 g / liter) of aluminum ions.

The temperature of the electrolytic solution is usually 10 to 60 ° C. As the alternating current used at this time, any of a rectangular wave, a trapezoidal wave, and a sine wave can be used as long as the positive and negative polarities are alternately exchanged. Phase alternating current can be used. The current density is 5 to 100 A / dm ² . Electrolysis time is 5
Treatment for ~ 300 seconds is desirable.

The surface roughness of the aluminum plate in the present invention is 0.2 to 0.8 μm. The aluminum plate grained in this way is heated to 10 to 50% hot sulfuric acid (40 to 60%).
It is preferable that the smut adhering to the surface is removed by (.degree. C.) or a dilute alkali (sodium hydroxide, etc.). When removed with an alkali, it is subsequently neutralized by immersion in an acid (nitric acid or sulfuric acid) for washing.

After removing the surface smut, an anodic oxide film is provided. Sulfuric acid is used as an electrolyte for anodic oxidation. The sulfuric acid may contain phosphoric acid. The sulfuric acid method is processed by direct current. Current density is 8-25
A / dm ² . When the photosensitive lithographic printing plate is subjected to a large-scale development treatment with a current density higher or lower than this, a deposit is accumulated on the bottom of the developing bath. The sulfuric acid is used at a concentration of 5 to 30%, and is electrolytically treated in the temperature range of 20 to 60 ° C. for 5 to 250 seconds to form an oxide film of 1 to 10 g / m ^{2 on} the surface. This electrolyte preferably contains aluminum ions. Further, if necessary, surface treatment such as sealing treatment with alkali silicate or hot water, or immersion in a water-soluble polymer compound or an aqueous solution of potassium fluorozirconate can be performed.

As the diazo resin contained in the photosensitive layer, conventionally known ones can be appropriately used, and examples thereof include a diazo resin represented by a condensation product of an aromatic diazonium salt and an active carbonyl-containing compound, especially formaldehyde. Of these, organic solvent-soluble diazo resins are preferable. As the diazo resin, for example, a diazo resin inorganic salt which is an organic solvent-soluble reaction product of a condensate of p-diazodiphenylamine and formaldehyde or acetaldehyde, and hexafluorophosphate or tetrafluoroborate, and US Pat. No. 3,300,309, the condensate and a sulfonic acid such as paratoluenesulfonic acid or a salt thereof, a phosphinic acid such as benzenephosphinic acid or a salt thereof, a hydroxyl group-containing compound such as 2,2
4-dihydroxybenzophenone, 2-hydroxy-4
Organic solvent-soluble diazo resin organic acid salts which are reaction products such as -methoxybenzophenone-5-sulfonic acid or a salt thereof.

The diazo compound including those described below is preferably contained in the photosensitive layer in an amount of 1 to 70% by weight, particularly 3 to 60% by weight. In the present invention, other diazo resins that can be suitably used include a carboxyl group,
A cocondensate containing, as constituent units, an aromatic compound having at least one group selected from the group consisting of a hydroxyl group, a sulfonic acid group, a sulfonic acid group, a sulfinic acid group, and a sulfinic acid group, and an aromatic diazonium compound.

The aromatic compound has, for example, at least one substituent selected from the group consisting of a carboxyl group, a hydroxyl group, a sulfonate group, a sulfonate group, a sulfinate group, and a sulfinate group on the benzene ring or naphthalene ring.
And each substituent may be directly bonded to the aromatic ring or may be bonded via a linking group. Specific examples of the aromatic diazonium compound include 4-diazo-
4'-methoxydiphenylamine salt, 4-diazo-4 '
-Ethoxydiphenylamine salt, 4-diazo-3-methoxydiphenylamine salt, 4-diazo-diphenylamine salt.

Specific examples of the aromatic compound include benzenesulfonic acid, sodium benzenesulfonate, 2-sodium m-benzenedisulfonic acid, p-toluenesulfonic acid, p-
Sodium toluenesulfonic acid, p-toluenesulfinic acid, sodium p-toluenesulfinate, sodium benzenesulfinate, aniline-2-sulfonic acid, 4-amino-m-toluenesulfonic acid, sodium 4-amino-m-toluenesulfonic acid 2,5-diaminobenzenesulfonic acid, 1-naphthalenesulfonic acid, 1-amino-2-naphthalenesulfonic acid, 5-amino-2-naphthalenesulfonic acid, 7-amino-1,3-naphthalenedisulfonic acid,
2-amino-1,5-naphthalenedisulfonic acid, 4-amino-1-naphthalenesulfonic acid sodium salt, 5-amino-
Sodium 1-naphthalenesulfonate, sodium 6-amino-1-naphthalenesulfonate, sodium 5-sulfoisophthalate, 2-sulfobenzoic acid, p-chlorobenzenesulfonic acid, benzoic acid, o-chlorobenzoic acid, m-chlorobenzoic acid Acid, p-chlorobenzoic acid, phthalic acid, terephthalic acid,
Diphenylacetic acid, phenoxyacetic acid, p-methoxyphenylacetic acid, p-methoxybenzoic acid, 2,4-dimethoxybenzoic acid, 2,4-dimethylbenzoic acid, p-phenoxybenzoic acid, 4-anilinobenzoic acid, 4- (m -Methoxyanilino) benzoic acid, 4- (p-methoxybenzoyl) benzoic acid, 4- (p-methylanilino) benzoic acid, 4-phenylsulfonylbenzoic acid, phenol, (o, m,
p) -cresol, xylenol, resorcin, 2-methylresorcin, (o, m, p) -methoxyphenol, m-ethoxyphenol, catechol, phloroglucin, p-hydroxyethylphenol, naphthol,
Pyrogallol, hydroquinone, p-hydroxybenzyl alcohol, 4-chlororesorcin, biphenyl 4,4
Diols, 1,2,4-benzenetriol, bisphenol A, 2,4-dihydroxybenzophenone,
2,3,4-trihydroxybenzophenone, p-hydroxyacetophenone, 4,4-dihydroxydiphenyl ether, 4,4-dihydroxydiphenylamine,
4,4'-dihydroxydiphenyl sulfide, cumylphenol, (o, m, p) -chlorophenol,
(O, m, p) -bromophenol, salicylic acid, 4-
Methyl salicylic acid, 6-methyl salicylic acid, 4-ethyl salicylic acid, 6-propyl salicylic acid, 6-lauryl salicylic acid, 6-stearyl salicylic acid, 4,6-dimethyl salicylic acid, p-hydroxybenzoic acid, 2-methyl-
4-hydroxybenzoic acid, 6-methyl-4-hydroxybenzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,4-dihydroxy-6-methylbenzoic acid, 2, 6-dihydroxybenzoic acid, 2,6-dihydroxy-4-methylbenzoic acid, 4
-Chloro-2,6-dihydroxybenzoic acid, 4-methoxy-2,6-dioxybenzoic acid, gallic acid, phloroglucin carboxylic acid, 2,4,5-trihydroxybenzoic acid, m-galloyl gallic acid, tannin Acid, m-benzoyl gallic acid, m- (p-toluyl) gallic acid, protocatechu oil-gallic acid, 4,6-dihydroxyphthalic acid, (2,4-dihydroxyphenyl) acetic acid, (2,6
-Dihydroxyphenyl) acetic acid, (3,4,5-trihydroxyphenyl) acetic acid, p-hydroxymethylbenzoic acid, p-hydroxyethylbenzoic acid, 4- (p-hydroxyphenyl) methylbenzoic acid, 4- (o- (Hydroxybenzoyl) benzoic acid, 4- (2,4-dihydroxybenzoyl) benzoic acid, 4- (p-hydroxyphenoxy) benzoic acid, 4- (p-hydroxyanilino) benzoic acid, bis (3-carboxy-4-) Hydroxyphenyl)
Examples thereof include amine, 4- (p-hydroxyphenylsulfonyl) benzoic acid, and 4- (p-hydroxyphenylthio) benzoic acid. Of these, salicylic acid, p-hydroxybenzoic acid, and p-methoxybenzoic acid are particularly preferable. ,
Metachlorobenzoic acid, phenoxyacetic acid, benzenesulfonic acid, sodium benzenesulfonic acid, p-toluenesulfonic acid, sodium p-toluenesulfonic acid, p-toluenesulfinic acid, sodium p-toluenesulfinate, benzenesulfinic acid, 5-sulfoisophthal Acid soda, 2-
Sulfobenzoic acid, 4-amino-m-toluenesulfonic acid, 4-amino-m-toluenesulfonic acid sodium, 1-
Naphthalenesulfonic acid, 2-amino-1,5-naphthalenedisulfonic acid, sodium 5-amino-1-naphthalenesulfonic acid, and p-chlorobenzenesulfonic acid.

The photosensitive diazo resin according to the present invention can be prepared by a known method, for example, Photographic Science and Engineering (Photo. Sci. Eng.) Vol. 17,
Page 33 (1973), U.S. Pat. No. 2,063,631,
The aromatic compound, aromatic diazonium salt and aldehydes such as paraformaldehyde, acetaldehyde, benzaldehyde or ketones such as acetone and acetophenone in sulfuric acid, phosphoric acid or hydrochloric acid according to the method described in each specification of 2,679,498. It is obtained by polycondensation.

The charged molar ratio of the aromatic diazo compound to the aromatic compound is 1: 0.1 to 0.1: 1, preferably 0.1.
5: 1 to 1: 0.2, more preferably 1: 1 to 1: 0.2. In this case, the total of the aromatic diazo compound and the aromatic compound and the aldehydes or ketones are usually charged in a molar ratio of 0.6 to 1.5: 1, preferably 0.7 to 1.4: 1. A diazo resin is obtained by reacting at a low temperature for a short time, for example, for about 3 hours.

Next, the counter anion X ⁻ of the diazo resin will be described. X ^- is preferably an aliphatic or aromatic sulfonic acid anion, preferred examples among them, methanesulfonic acid, fluoroalkanesulfonic acids such as trifluoromethanesulfonic acid, lauryl sulfonic acid, dioctyl sulfosuccinic acid, dicyclohexyl sulfosuccinate, camphor Sulfonic acid, tolyloxy-3-propanesulfonic acid, nonylphenoxy-3-propanesulfonic acid, nonylphenoxy-4-butanesulfonic acid, dibutylphenoxy-3-propanesulfonic acid, diamylphenoxy-3-propanesulfonic acid, dinonyl Phenoxy-3-propanesulfonic acid, dibutylphenoxy-4
-Butanesulfonic acid, dinonylphenoxy-4-butanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, mesitylenesulfonic acid, p-chlorobenzenesulfonic acid, 2,5-dichlorobenzenesulfonic acid, sulfosalicylic acid, 2,5-dimethyl Benzenesulfonic acid, p-
Acetylbenzenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-chloro-5-nitrobenzenesulfonic acid, butylbenzenesulfonic acid, octyl Benzenesulfonic acid,
Decylbenzenesulfonic acid, dodecylbenzenesulfonic acid, butoxybenzenesulfonic acid, dodecyloxybenzenesulfonic acid, 2-methoxy-4-hydroxy-5-
Benzoylbenzenesulfonic acid, isopropylnaphthalenesulfonic acid, butylnaphthalenesulfonic acid, hexylnaphthalenesulfonic acid, octylnaphthalenesulfonic acid, butoxynaphthalenesulfonic acid, dodecyloxynaphthalenesulfonic acid, dibutylnaphthalenesulfonic acid,
Dioctylnaphthalenesulfonic acid, triisopropylnaphthalenesulfonic acid, tributylnaphthalenesulfonic acid, 1-naphthol-5-sulfonic acid, naphthalene-1
-Sulfonic acid, naphthalene-2-sulfonic acid, 1,8-
Dinitro-naphthalene-3,6-disulfonic acid, 4,
4'-diazido-stilbene-3,3'-disulfonic acid, 1,2-naphthoquinone-2-diazide-4-sulfonic acid, 1,2-naphthoquinone-2-diazide-5-sulfonic acid and 1,2-naphthoquinone -1-diazide-4-
Includes sulfonic acid anions or mixtures of these anions. Particularly preferred among these anions are anions of alkyl-substituted naphthalenesulfonic acids such as butylnaphthalenesulfonic acid, dibutylnaphthalenesulfonic acid, dioctylnaphthalenesulfonic acid, and tributylnaphthalenesulfonic acid.

The diazo resin used in the present invention can have any desired molecular weight by varying the molar ratio of each monomer and the condensation conditions, but it is effective for the intended purpose of the present invention. Molecular weight of about 400
~ 100,000, preferably about 800-5,000
Is appropriate. The above-mentioned photosensitive diazo resin is preferably used in combination with an alkali-soluble or swellable lipophilic polymer compound as a binder resin.

Examples of such lipophilic polymer compounds are:
Copolymers having a molecular weight of usually from 100,000 to 200,000, using the monomers shown in the following (1) to (14) as structural units, can be mentioned. (1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, such as N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide , O-, m-, p-
Hydroxystyrene, o-, m-, p-hydroxyphenyl-acrylate or methacrylate, (2) acrylic acid ester having an aliphatic hydroxyl group, and methacrylic acid ester such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, (3) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, and itaconic acid, (4) methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, acrylic Octyl acid, acrylic acid-2
-(Substituted) alkyl acrylates such as -chloroethyl, glycidyl acrylate, N-dimethylaminoethyl acrylate, (5) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 4-
(Substituted) alkyl methacrylates such as hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate, (6) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide,
N-ethylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-
Acrylamide or methacrylamide such as N-phenylacrylamide, (7) ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, or other vinyl ethers, (8) vinyl acetate, Vinyl chloroacetate, vinyl butyrate, vinyl benzoate and other vinyl esters, (9) styrene, α-methyl styrene, chloromethyl styrene and other styrenes, (10) methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, Vinyl ketones such as phenyl vinyl ketone, (11) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene, (12) N-vinylpyrrolidone, N-vinyl Carbazole, 4-vinyl pyridine, acrylonitrile, methacrylonitrile, etc., (13) maleimide, N- acryloyl acrylamide,
Unsaturated imides such as N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide, (14) N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonyl) Methacrylic acid amides such as phenyl) methacrylamide, N- (p-amino) sulfonylphenylmethacrylamide, N- (1- (3-aminosulfonyl) naphthyl) methacrylamide, and N- (2-aminosulfonylethyl) methacrylamide. , And acrylamides having the same substituents as above, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate,
p-aminosulfonylphenyl methacrylate, 1-
Methacrylic acid esters such as (3-aminosulfonylnaphthyl) methacrylate, and unsaturated sulfonamides such as acrylic acid esters having the same substituents as above.

Further, a monomer copolymerizable with the above monomer may be copolymerized. Examples include, but are not limited to, those obtained by modifying a copolymer obtained by copolymerization of the above monomers with, for example, glycidyl methacrylate, glycidyl acrylate, or the like. More specifically, the above (1), (2), containing a monomer or the like listed in (14), a copolymer having a hydroxyl group or a sulfonamide group is preferable, having an aromatic hydroxyl group or a sulfonamide group Copolymers are more preferred.

The above copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the preferable carboxylic acid value of the copolymer is 0 to 3 meq / g, and more preferably 0.5. ~ 2.5 meq / g. The preferred molecular weight of the copolymer is from 150,000 to 150,000. If necessary, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, an epoxy resin, a novolak resin, a natural resin, or the like may be added to the copolymer.

The lipophilic polymer compound used in the present invention is usually contained in the solid content of the photosensitive composition in an amount of 40 to 99% by weight, preferably 50 to 95% by weight. Further, the photosensitive diazo resin used in the present invention is generally contained in an amount of 1 to 60% by weight, preferably 3 to 40% by weight. The photosensitive composition of the present invention may further contain a dye. The dye is
It is used for the purpose of obtaining a visible image by exposure (exposure visible image) and a visible image after development.

As the dye, those which "change color tone" by reacting with free radicals or acids can be preferably used. Here, "change in color tone" includes both a change from colorless to a color tone and a change from color to colorless or a different color tone. Preferred dyes are those which form a salt with an acid to change the color tone. For example, Victoria Pure Blue BOH [Hodogaya Chemical Co., Ltd.], Oil Blue # 603 [Orient Chemical Co., Ltd.], Patent Pure Blue [Sumitomo Mikuni Chemical Co., Ltd.], Crystal Violet, Brilliant Green, Ethyl Violet, Methyl Violet, Methyl Green, erythrosine B, basic fuchsin, malachite green, oil red, m-cresol purple, rhodamine B, auramine, triphenylmethane series represented by 4-p-diethylaminophenyliminaphthoquinone, cyano-p-diethylaminophenylacetanilide, etc., Diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes that change from colored to colorless or different colored tones And the like as.

On the other hand, examples of the discoloring agent that changes from colorless to colored include leuco dyes 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, Primary or secondary arylamine dyes represented by p ', p "-triaminotriphenylmethane are exemplified.

Particularly preferably, triphenylmethane type and diphenylmethane type dyes are effectively used, more preferably triphenylmethane type dyes, and particularly Victoria Pure Blue BOH. The dye is preferably contained in the photosensitive composition in an amount of usually about 0.5 to about 10% by weight, more preferably about 1 to 5% by weight.

Various additives can be further added to the photosensitive composition of the present invention. For example, alkyl ethers (eg, ethyl cellulose,
Methylcellulose), fluorinated surfactants, nonionic surfactants (especially fluorinated surfactants are preferred), plasticizers for imparting flexibility and abrasion resistance to coating films (for example, butylphthalyl, polyethylene glycol, Tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers and polymers of acrylic acid or methacrylic acid, among which And tricresyl phosphate are particularly preferred), and a sensitizing agent for improving the sensitizing property of the image area (for example, JP-A-55-52).
No. 7, a half-esterified product of a styrene-maleic anhydride copolymer with an alcohol, a novolak resin such as pt-butylphenol-formaldehyde resin, a 50% fatty acid ester of p-hydroxystyrene, etc.), a stabilizer [for example, Phosphoric acid, phosphorous acid, organic acids (citric acid, oxalic acid, dipicolinic acid, benzenesulfonic acid, naphthalenesulfonic acid, sulfosalicylic acid, 4-methoxy-2-hydroxybenzophenone-5-sulfonic acid, tartaric acid, etc.), development Accelerators (eg, higher alcohols, acid anhydrides, etc.) are preferably used. The amount of these additives depends on the intended use and purpose,
Generally, it is 0.01 to 30% by weight based on the total solid content.

In order to provide the above-mentioned photosensitive composition on a support, a photosensitive diazo co-condensation resin, a lipophilic polymer compound and, if necessary, various additives are added in predetermined amounts in a suitable solvent (methyl cellosolve). , Ethyl cellosolve, dimethoxyethane, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, 1-methoxy-2-
Dissolved in propanol, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethylformamide, dimethylacetamide, cyclohexanone, dioxane, tetrahydrofuran, methyl lactate, ethyl lactate, ethylene dichloride, dimethyl sulfoxide, water, or a mixture thereof). What is necessary is just to prepare a coating liquid for the product, apply it to the support, and dry it. The solid content concentration of the photosensitive composition at the time of application is 1 to 50.
It is desirable to be in the range of weight%. In this case, the application amount of the photosensitive composition may be about 0.2 to 10 g / m ² (dry weight).

On the photosensitive layer, there is preferably a mat layer composed of protrusions provided independently of each other. The purpose of the mat layer is to improve the vacuum adhesion between the negative image film and the photosensitive lithographic printing plate in contact exposure,
It is an object of the present invention to shorten the evacuation time and to prevent the fine halftone dots from being crushed during exposure due to poor adhesion.

A method for coating the matte layer is described in JP-A-55 / 55.
No. 12974, a method of thermally fusing powdered solid powder, and a method of spraying and drying polymer-containing water described in JP-A-58-182636, and any method may be used. However, it is desirable that the mat layer itself be dissolved in an aqueous alkaline developer containing substantially no organic solvent or be removable by this.

As the solid powder in the method of heat-sealing the powdered solid powder, preferably, the first or second transition point of the substance or composition is higher than 40 ° C., and the substance is Alternatively, the first or second transition point of the composition is lower than the first transition point of the photosensitive layer. Specific examples include polyvinyl acetate, polyvinylidene chloride, polyethylene oxide, polyethylene glycol, polyacrylic acid, polyacrylamide,
Examples include polyacrylate, polystyrene, polystyrene derivatives, copolymers of these monomers, polyvinyl methyl ether, epoxy resin, phenol resin, polyamide, and polyvinyl butyral.

The diameter of the solid powder particles is appropriately in the range of about 0.5 to 40 μ, preferably in the range of 1 to 17 μ, and particularly preferably in the range of 1 to 8 μ. Powdering is performed in a known manner, such as JJ Sokol, RC Hendrickson, Plastic Engineering Handbook,
P.426, P.431 (1976) (JJ Sokol and R.
Fluidized bed as described in C. Hendrickson Plastic Eng. Handbook (1976))
A method using an air spray, a brush, a buff, or the like may be used in addition to an electrostatic spray, an electrostatic fluidized bed, or the like.

The amount of the solid powder adhered to the surface of the photosensitive lithographic printing plate is 1 to 1, solid powder per 1 mm ² of the photosensitive lithographic printing plate.
000 pieces are suitable, and 5 to 500 pieces are preferable. The solid powder that is powdered and adheres to the surface of the photosensitive lithographic printing plate is generally randomly distributed. In order to fix the solid powder to the surface of the photosensitive lithographic printing plate, the solid powder that has been powdered and adhered to the surface of the photosensitive lithographic printing plate is fixed to the surface by heat.

That is, heated air is blown onto the powdered surface, or the surface of the solid powder is melted by passing the photosensitive lithographic printing plate which has been powdered through a heated air chamber or a heated roll. Fix to the surface of the planographic printing plate. In the present invention, the aqueous alkaline developer containing substantially no organic solvent means that the organic solvent is not excessively contained from the viewpoints of hygiene, safety and the like, and is generally a developer composition. There is no problem if the content is 2% by weight or less. Preferred organic solvent content is 1% by weight
The following is a more preferred embodiment. As the alkali agent used in the developer according to the present invention, preferably potassium silicate, lithium silicate, sodium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, Potassium triphosphate, dibasic potassium phosphate, sodium carbonate, potassium carbonate and the like can be mentioned. Among these, a developer containing an alkali silicate such as potassium silicate, lithium silicate, and sodium silicate is most preferable because of good development gradation, and the composition of the alkali silicate is [SiO ₂ ] / molar ratio. [M] = 0.5-1.5 (where [SiO ₂ ],
[M] indicates the molar concentration of SiO _{2 and} the molar concentration of total alkali metal, respectively. ), And and a developer containing SiO ₂ 0.8 to 8 wt% is preferably used. The pH (25 ° C.) of the developer according to the present invention is 12 or more, and preferably 1
2.5-14.

Further, in the developer, there is disclosed in JP-A-50-5132.
4, anionic surfactants and amphoteric surfactants, and nonionic surfactants as described in JP-A-59-75255 and JP-A-60-111246. To the photosensitive composition by containing at least one of the above-mentioned agents, or by including a polymer electrolyte as described in JP-A-55-95946 and JP-A-56-142528. It is possible to enhance wettability and further enhance gradation. The amount of the surfactant added is not particularly limited,
The concentration is preferably 0.003 to 3% by weight, particularly preferably 0.006 to 1% by weight. Further, potassium is 20 mol% in the total alkali metal as the alkali metal of the alkali silicate.
It is preferable that the content is not less than 90 mol%, and more preferable that the content of potassium is 100 mol% or more.
Is the case.

Further, if necessary, additives such as a defoaming agent and a water softener can be contained. Examples of the water softener include polyphosphates and aminopolycarboxylic acids. The optimum amount of such a water softener varies depending on the hardness of the hard water used and the amount used. However, if a general amount is used, 0.01 to 5% by weight in the developer at the time of use is used. , More preferably 0.01 to 0.5.
It is contained in the range of weight%.

As such an aqueous alkaline developer containing substantially no organic solvent, for example, JP-A-59-8424 is used.
No. 1, JP-A-57-192952, etc., and a developer composition used for developing a positive type lithographic printing plate after image exposure and then developing. Furthermore, in the development process of this type of photosensitive lithographic printing plate, the alkali aqueous solution is consumed depending on the processing amount, and the alkali concentration is reduced, or the alkali concentration is reduced by air due to long-time operation of the automatic developing solution. Although the processing capacity is reduced, the processing capacity may be restored by using a replenisher as described in JP-A-54-62004.

If necessary, desensitizing treatment after development treatment, washing with water, desensitizing treatment as it is, or treatment with an aqueous solution containing an acid, or desensitizing treatment after treatment with an aqueous solution containing an acid. May be given.

[0043]

In the present invention, the pH of the aluminum electrolytically roughened surface anodized in a sulfuric acid bath at a direct current of 8 to 25 A / dm ^{2 in} a sulfuric acid bath is used.
Even if a strong alkaline water of 12 or more is used as a developing solution, a part of the anodized film on the aluminum surface is not eluted as aluminate ions in the developing solution, and dust and sludge are less likely to be generated. Therefore, a large number of photosensitive lithographic printing plates can be developed.

In the present invention, since an aqueous alkaline developer containing substantially no organic solvent is used at the time of development processing, there are problems in hygiene such as toxicity and odor during work, and safety problems such as fire and gas explosion. Moreover, there is no problem such as pollution caused by the waste liquid, and it can be implemented at low cost. In the present invention, a negative type lithographic printing plate can be developed using an aqueous alkaline developer known as a developing solution for a positive type lithographic printing plate. For this reason, when processing both the positive type lithographic printing plate and the negative type lithographic printing plate, to prepare a developer composition to suit each, or to replace the developer composition,
It is possible to omit the work of preparing two types of developer compositions and a development processing apparatus in advance, and the working efficiency, equipment cost, arrangement space, and the like are significantly improved.

Next, typical synthesis examples of the diazo resin according to the present invention will be shown. [Synthesis Example] Synthesis of diazo resin-1 3.5 g (0.025 mol) of p-hydroxybenzoic acid and 7.1 g (0.025 mol) of 4-diazodiphenylamine sulfate were dissolved in 90 g of concentrated sulfuric acid under water cooling. did. To this reaction was slowly added 2.7 g of paraformaldehyde (0.09 mol). At this time, the reaction was added so that the reaction temperature did not exceed 10 ° C. Thereafter, stirring was continued under ice cooling for 2 hours. The reaction mixture was poured into 1 liter of ethanol under ice cooling, and the resulting precipitate was filtered. After washing with ethanol, the precipitate was dissolved in 200 ml of pure water, and to this solution was added a cold concentrated aqueous solution in which 10.5 g of zinc chloride was dissolved.
The resulting precipitate was filtered and washed with ethanol.
It was dissolved in 00 ml of pure water. To this solution was added a cold concentrated aqueous solution in which 28.7 g of sodium dibutylnaphthalenesulfonate was dissolved. The resulting precipitate was filtered off and washed with water, and then 30 ° C, 1
It was dried day and night to obtain diazo resin-1.

When the molecular weight of this diazo resin-1 was measured by GPC (gel permeation chromatography), the weight average molecular weight was about 1600. Synthesis of diazo resin-2 Diazo resin-2 was obtained in the same manner as in the synthesis of diazo resin-1, except that p-hydroxybenzoic acid was changed to 4.5 g of sodium benzenesulfonate in the synthesis of diazo resin-1.

When the molecular weight was measured by GPC, the weight average molecular weight was 1650. Synthesis of diazo resin-3 Diazo resin-3 was obtained in the same manner as in the synthesis of diazo resin-1 except that sodium dibutylnaphthalenesulfonate was replaced with ammonium hexafluorophosphate in the synthesis of diazo resin-1.

Next, synthetic examples of lipophilic polymer compounds will be shown. Synthesis of lipophilic polymer compound-1 N- (4-hydroxyphenyl) methacrylamide 53
g, acrylonitrile 16 g, methyl methacrylate 30
g, 8 g of ethyl acrylate, 2 g of methacrylic acid and 3.3 g of azobisisobutyronitrile were dissolved in 220 ml of a 1: 1 mixed solvent of acetone-ethanol, and the mixture was purged with nitrogen and heated at 60 ° C. for 8 hours.

After completion of the reaction, the reaction solution was poured into 5 liters of water with stirring, and the resulting white precipitate was collected by filtration and dried to obtain 90 g of polymer compound-1. This lipophilic polymer compound-1 is represented by G
When the molecular weight was measured by PC, the weight average molecular weight was 29,000. Synthesis of lipophilic polymer compound-2 N- (p-aminosulfonylphenyl) methacrylamide 4.57 g (0.0192 mol), acrylonitrile 2.55
g (0.0480 mol), methacrylic acid 1.66 g (0.019 g)
2 mol), 18.40 g (0.1136 g) of benzyl acrylate
mol), 0.41 g of α, α'-azobisisobutyronitrile
And 25 g of N, N-dimethylformamide,
Put into a 100 ml three-necked flask equipped with a cooling tube,
While stirring for 5 hours. This reaction mixture was poured into 2 liters of water with stirring, stirred for 30 minutes, filtered and dried to obtain 19 g of polymer compound-2.
The weight average molecular weight (polystyrene standard) of this polymer compound-2 measured by GPC was 18,000. Example 1 A JIS A1050 aluminum plate containing 0.02% copper, 0.01% titanium, 0.30% iron and 0.1% silicon was etched with a 5% sodium hydroxide aqueous solution at 50 ° C. for 10 seconds. After that, it was neutralized in a 30% nitric acid bath at 25 ° C. for 30 seconds, then electrolytically surface-roughened in a 2% hydrochloric acid bath at 25 ° C. with an alternating current of 25 A / dm ² for 1 minute, and then Neutralize with 1% sodium hydroxide aqueous solution at 20 ° C for 30 seconds, then wash with water,
% Sulfuric acid bath at 30 ° C. and 10 A / dm ² for 20 seconds anodizing treatment. Next, a 1% aqueous solution of sodium metasilicate was sealed at 85 ° C. for 30 seconds, washed with water and dried to obtain an aluminum plate for lithographic printing.

Photosensitive solution 1 having the following composition was applied to this aluminum plate so that the film weight after drying would be 1.7 g / m ² . Photosensitive solution-1 Lipophilic polymer compound-1 5.0 g Diazo resin-1 0.6 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.1 g Julimer AC-10L (manufactured by Nippon Pure Chemical Co., Ltd.) 0.3 g Methyl cellosolve 100 ml On this photosensitive layer, a solid powder composed of the following resin, which was pulverized with a ball mill and classified with a classifier (Zigzag classifier manufactured by Albime Co., Ltd.), was powdered with a spray gun and heated at 150 ° C. For 5 seconds to fix. 1
The amount of powder per mm ² was 55. Solid powder resin: styrene / methyl acrylate / acrylic acid (2: 1: 1) copolymer powder having a particle size of 0.5 to 10 μm The obtained photosensitive lithographic printing plate is prepared using a negative transparent original and a step wedge (optical). (The density was increased stepwise by 0.150), and exposure was performed with a 5 KW metal halide lamp from a distance of 1 m for 30 seconds.

Further, development processing was performed under the following conditions.
In other words, Fuji Photo Film Co., Ltd.'s automatic machine Stublon 9
00D, the following developer 1 and finisher FN-2 manufactured by Fuji Photo Film Co., Ltd. were charged, and the developer temperature was 3
The treatment was performed at 0 ° C. to obtain a lithographic printing plate. Composition of developer-1 1K potassium silicate 60g potassium hydroxide 12g boron-based surfactant (Emalbon T-20) 0.1g chelating agent (EDTA) 0.1g silicon-based defoamer (TSA-731 manufactured by Toshiba) 1 g Cobalt acetate 0.3 g Water 600 g Developer-1 had a pH of 13.1.

The lithographic printing plate thus obtained was used to print on high-quality paper with a commercially available ink using an SOR printer manufactured by Heidelberg. Further, the above-mentioned photosensitive lithographic printing plate was subjected to a large amount of developing treatment under the above-mentioned developing conditions until it became equivalent to 50 m ² per liter of developing solution and then left for 3 days, and observed for deposits on the bottom of the developing machine developing bath. did. Table 1 shows the obtained results. Example 2 The procedure of Example 1 was repeated except that the diazo resin-1 was replaced by the diazo resin-2 in the photosensitive solution-1 of Example 1. Example 3 The procedure of Example 1 was repeated except that the diazo resin-1 was replaced with the diazo resin-3 in the photosensitive solution-1 of Example 1.

The procedure of Example 1 was repeated, except that the lipophilic polymer compound-1 was replaced with the lipophilic polymer compound-2 in the photosensitive solution-1 of Example 1. Comparative Example 1 The procedure of Example 1 was repeated, except that the current density for anodic oxidation in the support of Example 1 was changed to 2 A / dm ² . Comparative Example 2 The procedure of Example 1 was repeated, except that the anodizing current density in the support of Example 1 was changed to 40 A / dm ² .

[0054] Good printed matter was obtained in all of Examples 1 to 4 and Comparative Examples 1 and 2. As can be seen from Table 1, according to the present invention, dust and sludge are not generated on the bottom of the developing bath even when a large amount of processing is performed using a developing solution containing substantially no organic solvent, which is very excellent.

Claims (2)

(57) [Claims] 1. A surface treated with hydrochloric acid electrolytic surface roughening treatment for 8 to 25
At least one group selected from the group consisting of a carboxyl group, a hydroxyl group, a sulfonic acid group, a sulfinic acid group, and a sulfinic acid base on an aluminum support anodized in a sulfuric acid bath at a direct current with a current density of A / dm ^2. After an image exposure of a photosensitive lithographic printing plate obtained by coating a photosensitive layer containing a co-condensed diazo resin containing an aromatic compound having an aromatic diazonium compound as a constitutional unit and a lipophilic polymer compound, A method for producing a lithographic printing plate, which comprises developing the lithographic printing plate with an alkaline aqueous solution having a pH of 12 or more and substantially not containing an organic solvent. 2. The method for producing a lithographic printing plate according to claim 1, wherein the lipophilic polymer compound is a polymer compound containing a constitutional unit having an aromatic hydroxyl group.