JP3142185B2 - Manufacturing method of photosensitive lithographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method for producing a photosensitive lithographic printing plate. More specifically, the present invention relates to a method for producing a photosensitive lithographic printing plate excellent in inking property and printing durability.

[0002]

2. Description of the Related Art The majority of those used as photosensitive materials in photosensitive lithographic printing plates to which photosensitivity has been given in advance are diazonium compounds. Among them, the most commonly used one is formaldehyde condensation of p-diazodiphenylamine. There is a diazo resin represented by a product. The composition of the photosensitive layer of a photosensitive lithographic printing plate using a diazo resin is, for example, as described in U.S. Pat.No. 2,714,066, a diazo resin alone, that is, one without a binder,
For example, as described in JP-A-50-30604, it can be classified into a mixture of a binder and a diazo resin. In particular, in recent years, many photosensitive lithographic printing plates using a diazonium compound have a photosensitive layer composed of a binder and a diazo resin in order to impart high printing durability. As such a photosensitive layer, as described in JP-A-50-30604, a so-called alkali developing type in which unexposed portions are removed (developed) by an aqueous alkali developing solution, and an organic solvent-based developing solution A so-called solvent development type which is removed is known. In recent years, alkali development type has attracted attention for occupational safety and health, and this is mainly determined by the properties of the binder. Examples of a method for imparting alkali developability to a binder include a method of copolymerizing a carboxyl group-containing monomer as described in JP-A-50-30604, and U.S. Pat. No. 2,861,058. As described above, there is a method of introducing a carboxyl group into a binder by reacting a hydroxyl group of polyvinyl alcohol with a cyclic acid anhydride such as phthalic anhydride. However, the obtained photosensitive layer was insufficient in the inking property and printing durability, which are important properties of the lithographic printing plate. Therefore, in order to improve the inking property, a method of adding a polymer compound having a higher oil sensitivity than a binder as described in JP-A-55-527 has been proposed. It was insufficient and further improvement was desired. On the other hand, printing durability is determined by the adhesion between the support and the photosensitive layer, the wear resistance of the photosensitive layer, and the oil sensitivity of the photosensitive layer. JP-A-63-259558 describes a method for improving the printing durability of a photosensitive lithographic printing plate obtained by applying a diazo resin and a binder to a support using a coating solvent containing 1-methoxy-2-propanol and drying. As described in Japanese Patent Application Laid-Open Publication No. H11-209, a method of adding 2% by weight or more of methyl lactate to the total solvent has been proposed, but it is still insufficient and further improvement has been desired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a photosensitive lithographic printing plate which is alkali developable and has further improved in-coating and printing durability.

[0004]

The present inventor has conducted various studies to achieve the above object. As a result, the diazo resin a whose counter anion is an inorganic acid anion or an aliphatic organic acid anion having 3 or less carbon atoms was obtained. A negative photosensitive composition containing a diazo resin b whose counter anion is an aliphatic or aromatic organic acid anion having 6 or more carbon atoms and a binder is prepared by adding 1-methoxy-2-propanol to 10 to 100% by weight. It has been found that a photosensitive lithographic printing plate satisfying the above objects can be produced by dissolving in a coating solvent containing the solution, applying the solution on a support having a hydrophilic surface, and drying. The diazo resin used in the present invention is a diazo resin represented by a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound, for example, formaldehyde, or a carboxyl group, a sulfonic acid group, a sulfinic acid group, an oxygen acid of phosphorus. Diazo resin containing an aromatic compound having at least one of a group and a hydroxyl group and an aromatic diazonium compound as constituent units, or an aromatic amine, phenol, phenol ether, aromatic thioether, aromatic hydrocarbon, aromatic Heterocyclic compounds,
A co-condensed diazo resin containing, as constituent units, an aromatic compound having an organic acid amide and an aromatic diazonium compound. Examples of the inorganic acid or an aliphatic organic acid having 3 or less carbon atoms that form a counter anion of the diazo resin a include hexafluorophosphoric acid, tetrafluoroboric acid, phosphoric acid, phosphotungstic acid, thiocyanic acid, methanesulfonic acid, and ethanesulfonic acid. Acids, propanesulfonic acid, trifluoromethanesulfonic acid or mixtures thereof. Particularly preferred among these are hexafluorophosphoric acid and tetrafluoroboric acid.

On the other hand, aliphatic or aromatic organic acids having 6 or more carbon atoms forming a counter anion of diazo resin b include:
2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 5-sulfosalicylic acid, paratoluenesulfonic acid, laurylsulfonic acid, dioctylsulfosuccinic acid, dicyclohexylsulfosuccinic acid, camphorsulfonic acid, tolyloxy-3-propanesulfonic acid, nonylphenoxy -3-propanesulfonic acid, nonylphenoxy-4-butanesulfonic acid, dibutylphenoxy-3
-Propanesulfonic acid, diamylphenoxy-3-propanesulfonic acid, dinonylphenoxy-3-propanesulfonic acid, dibutylphenoxy-4-butanesulfonic acid, dinonylphenoxy-4-butanesulfonic acid, benzenesulfonic acid, mesitylenesulfone Acid, p-chlorobenzenesulfonic acid, 2,5-dichlorobenzenesulfonic acid, 2,5-dimethylbenzenesulfonic 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, octylbenzenesulfonic 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- -Sulfonic acid, 1,8-dinitronaphthalene-3,6-disulfonic acid, 4,4'-diazido-stilbene-3,3'-disulfonic acid, 1,2-naphthoquinone-2-diazido-4-sulfonic acid, 1,2-naphthoquinone-2-diazide-5-sulfonic acid, 1,2-
Naphthoquinone-1-diazide-4-sulfonic acid or a mixture thereof. Among them, particularly preferred are dodecylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, and octylnaphthalenesulfonic acid.

In the present invention, a diazo resin a in which a counter anion is an inorganic acid anion or an aliphatic organic acid anion having 3 or less carbon atoms, and a diazo resin a in which the counter anion is an aliphatic or aromatic organic acid anion having 6 or more carbon atoms. The weight ratio with a certain diazo resin b is preferably in the range of 0.1: 0.9 to 0.9: 0.1, more preferably 0.2: 0.8 to 0.8: 0.2. Range. When the ratio of the diazo resin a is smaller than 0.1 (when the ratio of the diazo resin b is larger than 0.9), the adhesion to the support is poor and the printing durability is reduced. On the other hand, when the ratio of the diazo resin a is larger than 0.9 (when the ratio of the diazo resin b is smaller than 0.1), the inking property is reduced, the abrasion resistance of the photosensitive layer is poor, and the printing durability is poor. descend.

The binder used in the present invention includes the following:
Normally, the monomer represented by (1) to (15) has a structural unit of 1
Copolymers having a molecular weight of ２０200,000 are exemplified. (1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, such as N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide, o-, m-, p-hydroxystyrene, o-, m-, p-hydroxyphenyl-acrylate or methacrylate and o-, m-, p
-Hydroxystyrene, (2) acrylates and methacrylates having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, (3) acrylic acid, methacrylic acid, maleic anhydride, itaconic acid , Unsaturated carboxylic acids such as muconic acid, (4) methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate,
(Substituted) alkyl acrylates such as 2-chloroethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate, (5) methyl methacrylate, ethyl methacrylate, propyl methacrylate,
(Substituted) alkyl methacrylates such as butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 4-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-N- Acrylamide and methacrylamides such as phenylacrylamide, (7) vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether; (8) vinyl acetate, vinyl chloro Vinyl esters such as acetate, vinyl butyrate and vinyl benzoate, (9) styrene, α-methylstyrene, Rusuchiren, styrenes such as chloromethylstyrene, (10) methyl vinyl ketone,
Vinyl ketones such as ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone; (11) olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene; (12) N-vinylpyrrolidone, N-vinylcarbazole, and 4-vinylpyridine , Acrylonitrile,
Methacrylonitrile and the like, (13) maleimide, N-acryloylacrylamide, N-acetylmethacrylamide,
Unsaturated imides such as N-propionyl methacrylamide, N- (p-chlorobenzoyl) methacrylamide,

(14) N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-amino) sulfonylphenylmethacrylamide, N- (1- (3- Aminosulfonyl) naphthyl) methacrylamide, N- (2
Methacrylamides such as -aminosulfonylethyl) methacrylamide, acrylamides having the same substituents as described above, and o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate,
Unsaturated sulfonamides such as methacrylic esters such as-(3-aminosulfonylnaphthyl) methacrylate, and acrylic esters having the same substituents as described above; (15) N- [2- (methacryloyloxy) -ethyl]-
Unsaturated monomers having a crosslinkable group in the side chain, such as 2,3-dimethylmaleimide and vinyl cinnamate. Further, a monomer copolymerizable with the above monomer may be copolymerized. In addition, a copolymer obtained by copolymerization of the above-mentioned monomers, for example, modified with glycidyl methacrylate, glycidyl acrylate, or the like is also included, but is not limited thereto. The above copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the preferable carboxylic acid value of the copolymer is 0.1 to 3.0 meq / g.
(Milli-equivalent of acid component per 1 g of binder), more preferably 0.5 to 2.5 meq / g. Carboxylic acid value is
If it is less than 0.1 meq / g, development is difficult, and 3.0 meq / g.
If the ratio exceeds, the image intensity at the time of development becomes extremely weak.

Further, among the monomers (1) to (15), the following monomers are particularly preferable. That is,
(1), a monomer having an aromatic hydroxyl group or a sulfonamide group listed in (14), (2), a monomer listed in (12), particularly 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate or acrylonitrile, Further, copolymers containing the monomers listed in the above (4) and (5), especially ethyl acrylate, butyl acrylate, benzyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate or benzyl methacrylate are preferred. 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. In addition, JP-B-54-19773, JP-A-57-94747 and JP-A-57-94747, in which polyvinyl acetal and polyurethane are solubilized with alkali.
Nos. 0-182437, 62-58242 and 62-
The binder described in 123453 is also useful. Further, a binder obtained by alkali-solubilizing a polyvinyl alcohol derivative, a polyvinylpyrrolidone derivative, or a cellulose derivative is also useful.

The total amount of these diazo resins and the content of the binder in the photosensitive layer of the photosensitive lithographic printing plate are 3 to 30% by weight of the diazo resin and 97 to 70% by weight of the binder based on the total amount of both. Is appropriate. When the content of the diazo resin is small, the sensitivity is high, but when the content is lower than 3% by weight, it is insufficient for photocuring the binder, and the photocured film swells with the developing solution during development, and the film becomes weak. Conversely, if the content of the diazo resin is more than 30% by weight, the sensitivity is lowered and practical difficulties arise. Therefore, a more preferable range is 5 to 25% by weight of the diazo resin and 95 to 75% by weight of the binder. A diazo resin in which the counter anion used in the present invention is an inorganic acid anion or an aliphatic organic acid anion having 3 or less carbon atoms, and a diazo resin in which the counter anion is an aliphatic or aromatic organic acid anion having 6 or more carbon atoms. It is surprising that the photosensitive composition containing the resin b and the binder is dissolved in a coating solvent containing 10 to 100% by weight of 1-methoxy-2-propanol, applied to a hydrophilic support, and dried. In particular, they have found that the inking property and printing durability are significantly improved. The optimum amount of 1-methoxy-2-propanol varies depending on the drying conditions and the type of the binder, and the type and amount of the other solvent, but more preferably 15 to 80% by weight, particularly preferably 20 to 60% by weight. It is. When the content of 1-methoxy-2-propanol is less than 10% by weight, the inking property and printing durability are reduced.

Various other solvents can be mixed with the coating solvent in the present invention. It is preferable to mix a low-boiling-point solvent in order to dry with a small drying energy and to unevenly disperse the high oil-sensitive polymer compound on the surface of the photosensitive layer.
Specific examples of the low boiling point solvent include 1,2-dichloroethane, 1,1-dichloroethane, 1,1,1-trichloroethane, cis-1,2-dichloroethane, 1,2-dichloropropane, butyl chloride, and chlorobromomethane. Halogenated hydrocarbons such as methanol, ethanol, n-propanol, isopropanol, aliphatic alcohols such as secondary butyl alcohol and tertiary butyl alcohol, and ether or ketone compounds such as tetrahydrofuran, tetrahydropyran, ethylene glycol dimethyl ether, acetone and methyl ethyl ketone , Ethyl formate, propyl formate, isobutyl formate, methyl acetate, ethyl acetate,
Ester compounds such as isopropyl acetate, methyl propionate, and ethyl propionate are exemplified. The content of the low boiling solvent is preferably from 40 to 80% by weight. A small amount of water can be further added to the coating solvent in the present invention.
The amount of water added is 10% by weight or less of the total solvent. Preferably it is 1 to 7% by weight. To the coating solvent in the present invention, a trace amount of a high boiling point solvent can be further added for the purpose of increasing the solubility of the photosensitive diazo resin or improving the compatibility between the photosensitive diazo resin and the binder. Specific examples of such a high boiling point solvent include dimethyl sulfoxide, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol, triethylene glycol monomethyl ether, triethylene glycol, ethylene glycol monophenyl ether, and phosphoric acid. Trimethyl,
Triethyl phosphate, ethylene carbonate, trioxane, γ-
Butyrolactone, γ-valerolactone, diacetone alcohol, methyl acetoacetate, tetrahydrofurfuryl alcohol, dimethylformamide, acetylacetone,
Examples include cyclohexanone, methyl lactate, ethyl lactate, diethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, and 2-methyl-2-methoxy-4-pentanone. The amount of these high-boiling solvents added is up to 20% by weight of the total solvent. Preferably 1
It is 5.0 to 0.5% by weight.

The photosensitive composition of the present invention may further contain a dye. The dye 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 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-diethylaminophenyliminaphthoquinone, triphenylmethane series, diphenylmethane series, oxazine series represented by cyano-p-diethylaminophenylacetanilide, etc. , Xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes that change from colored to colorless or different colored tones.

On the other hand, dyes that change 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, p, Primary or secondary arylamine dyes represented by p ', p "-triaminotriphenylmethane are exemplified. Particularly preferably, triphenylmethane-based and diphenylmethane-based dyes are effectively used, more preferably triphenylmethane-based dyes, and particularly Victoria Pure Blue BOH. The above dye is usually contained in the solid content of the photosensitive composition in an amount of about 0.5.
The content is preferably 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), a fluorine-based or nonionic surfactant (particularly preferred is a fluorine-based surfactant), a plasticizer for imparting flexibility and abrasion resistance of a coating film (for example, butylphthalyl, polyethylene glycol, tributyl citrate, Diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate,
Oligomers and polymers of tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid, of which tricresyl phosphate is particularly preferred), and a sensitizing agent for improving the lipophilicity of the image area ( For example, a half-esterified product of a styrene-maleic anhydride copolymer with an alcohol described in JP-A-55-527, a novolak resin, a 50% fatty acid ester of p-hydroxystyrene, etc.), a stabilizer [for example,
Phosphoric acid, phosphorous acid, organic acids (citric acid, oxalic acid, malic acid, dipicolinic acid, benzenesulfonic acid, naphthalenesulfonic acid, sulfosalicylic acid, 4-methoxy-2-hydroxybenzophenone-5-sulfonic acid, tartaric acid, etc.) And a development accelerator (eg, higher alcohol, acid anhydride, etc.). The amount of these additives varies depending on the object and purpose of use, but is generally 0.01 to 30% by weight based on the solid content of the photosensitive composition.

The solid concentration of the photosensitive composition at the time of coating is preferably in the range of 1 to 50% by weight. In this case, the coating amount of the photosensitive composition is generally 0.2 to 10 g /
m ² (dry weight).
0.5 to 3 g / m ² . The coating solution is applied on a support by a known coating technique. Examples of the coating technique include a spin coating method, a wire bar coating method, a dip coating method, an air knife coating method, a roll coating method, a blade coating method, a curtain coating method, and a spray coating method. As a support, paper, plastic (for example,
Polyethylene, polypropylene, polystyrene, etc.) laminated paper, aluminum (including aluminum alloy),
Plates of metals such as zinc, copper, etc., plastic films such as cellulose diacetate, cellulose triacetate, cellulose propionate, polyethylene terephthalate, polyethylene-polypropylene, polycarbonate, polyvinyl acetal, etc., and the above-mentioned metals are laminated or vapor-deposited Paper or plastic film, aluminum or chrome-plated copper plate, etc., of which aluminum and aluminum-coated composite support are particularly preferable.

The surface of the aluminum material is desirably surface-treated for the purpose of increasing water retention and improving adhesion to the photosensitive layer. For example, as a roughening method,
Commonly known brush polishing methods, ball polishing methods, electrolytic etching, chemical etching, liquid honing, methods such as sand blasting and combinations thereof, preferably include brush polishing methods, electrolytic etching, chemical etching and liquid honing. Among them, a surface roughening method including the use of electrolytic etching is particularly preferable.
Further, as described in JP-A-54-63902, a method of performing brush polishing followed by electrolytic etching is also preferable. Further, as the electrolytic bath used in the case of electrolytic etching, an aqueous solution containing an acid, an alkali or a salt thereof or an aqueous solution containing an organic solvent is used, and among these, particularly, hydrochloric acid, nitric acid or a salt thereof is included. Electrolytes are preferred. Further, the roughened aluminum plate is desmutted with an acid or alkali aqueous solution as required.

The aluminum plate thus obtained is desirably subjected to anodic oxidation treatment, particularly preferably a method of treating it with a bath containing sulfuric acid or phosphoric acid. Further, if necessary, silicates described in U.S. Pat. No. 2,714,066 and U.S. Pat.
(Sodium silicate, sodium silicate) treatment, potassium fluoride zirconate treatment described in U.S. Pat.No. 2,946,638, phosphomolybdate treatment described in U.S. Pat.No. 3,201,247, UK patent 1,
Alkyl titanate treatment described in No. 108,559,
Polyacrylic acid treatment described in German Patent No. 1,091,433, polyvinyl phosphonic acid treatment described in German Patent No. 1,134,093 and British Patent No. 1,230,447, JP-B-44-6409. JP-A-58-168, a phosphonic acid treatment described in JP-A-58-168, a phytic acid treatment described in U.S. Pat. No. 3,307,951.
No. 93 and JP-A-58-18291, treatment with a salt of a hydrophilic organic polymer compound with a divalent metal, and sulfonic acid described in JP-A-59-101651. Particularly preferred are those subjected to a hydrophilic treatment by undercoating a water-soluble polymer having a group, and those colored by an acid dye described in JP-A-60-64352. Other hydrophilic treatment methods include silicate electrodeposition described in U.S. Pat. No. 3,658,662. Further, after graining treatment and anodic oxidation, sealing treatment is preferable. Such a sealing treatment is performed by immersion in hot water and a hot aqueous solution containing an inorganic salt or an organic salt, a steam bath, or the like.

More specifically about the support suitable for use in the present invention, 0.1-0.5% iron and silicon
A 1S aluminum plate containing 0.03% to 0.3%, 0.001% to 0.03% of copper, and 0.002% to 0.1% of titanium is alkali-preferably 1% to 30% of sodium hydroxide. And immersion in an aqueous solution of potassium hydroxide, sodium carbonate, sodium silicate or the like at a temperature of 20 to 80 ° C. for 5 seconds to 250 seconds for etching. Aluminum ions may be added to the etching bath in an amount of about one-fifth of alkali. Then
It is immersed in a 10 to 30% nitric acid or sulfuric acid aqueous solution at a temperature of 20 to 70 ° C. for 5 to 250 seconds to neutralize and remove smut after alkali etching. After the surface of the aluminum alloy plate is cleaned, a surface roughening process is performed. As the roughening treatment, brush polishing and / or electrolytic etching treatment is suitable. For brush polishing, it is preferable to use a pumistone-water suspension and a nylon brush, and it is preferable to set the average surface roughness to 0.25 to 0.9 μ. The electrolytic solution used for the electrolytic etching treatment is an aqueous solution of hydrochloric acid or nitric acid, and the concentration is preferably used in the range of 0.01 to 3% by weight, and more preferably 0.05 to 2.5% by weight. preferable. The electrolyte may contain a corrosion inhibitor (or stabilizer) such as nitrate, chloride, monoamines, diamines, aldehydes, phosphoric acid, chromic acid, boric acid, and ammonium oxalate, as necessary. A graining agent and the like can be added. Also, an appropriate amount (1 to 1)
0 g / liter) of aluminum ions.

The electrolytic etching process is usually performed at 10 to 60 ° C.
At the temperature of the electrolyte. If the alternating current used at this time is one in which the positive and negative polarities are alternately exchanged,
Any of a rectangular wave, a trapezoidal wave, and a sine wave can be used, and normal commercial AC single-phase and three-phase AC currents can be used. The current density is 5 to 100 A / dm ² ,
It is desirable to process for 10 to 300 seconds. The surface roughness of the aluminum alloy support in the present invention is adjusted by the quantity of electricity, and is set to 0.2 to 0.8 μm. The grained aluminum alloy is removed and etched (preferably 0.1%) of the smut attached to the surface with 10 to 50% hot sulfuric acid (40 to 60 ° C.) or a dilute alkali (such as sodium hydroxide). (In the range of from 0.01 to 2.0 g / m ² ). If the smut has been removed and etched with an alkali, it is subsequently neutralized by immersion in an acid (nitric acid or sulfuric acid) for cleaning. After de-smutting the surface, an anodic oxide coating is provided. As the anodic oxidation method, a conventionally well-known method can be used, but sulfuric acid is used as the most useful electrolytic solution. Subsequently, phosphoric acid is also a useful electrolyte. Furthermore, Japanese Unexamined Patent Publication No.
The mixed acid of sulfuric acid and phosphoric acid disclosed in JP-A-5-28400 is also useful.

In the sulfuric acid method, the treatment is usually performed with a direct current, but an alternating current can also be used. Sulfuric acid concentration 5-3
It is electrolyzed in a temperature range of 0%, 20 to 60 ° C for 5 to 250 seconds, and an oxide film of 1 to 10 g / m ² is provided on the surface. The electrolyte preferably contains aluminum ions. Further, the current density at this time is 1 to
20 A / dm ² is preferred. 5-5 in case of phosphoric acid method
0% phosphoric acid concentration, 30-60 ° C, 10-30
The treatment is performed at a current density of 1 to 15 A / dm ² for 0 second. The aluminum support thus treated is preferably further subjected to a surface treatment with silicates as described in U.S. Pat. No. 2,714,066. Further, the aluminum support may be subbed.

Examples of the compound used for the undercoat include phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, phenylphosphonic acid which may have a substituent, and naphthylphosphonic acid. Organic phosphonic acids such as alkylphosphonic acid glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, phenylphosphoric acid which may have a substituent, naphthylphosphoric acid, organic phosphoric acid such as alkylphosphoric acid and glycerophosphoric acid, Organic phosphinic acids such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent, amino acids such as glycine and β-alanine, and hydroxyl such as triethanolamine hydrochloride Water-soluble polymer having a hydrochloride salt, a sulfonic acid group as described in JP-A-59-101651 amine with, and JP 60-64352
The acid dyes described in JP-A No. 2000-163, etc. are preferably used. This undercoat layer can be provided by dissolving the above compound in water, methanol, ethanol, methyl ethyl ketone, or the like, or a mixed solvent thereof, coating the support on a support, and drying. Further, a yellow dye may be added for improving the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the undercoat layer after drying is suitably from ² to 200 mg / m ² , and preferably from 5 to 100 mg / m ² .

It is preferable to provide a mat layer composed of protrusions provided independently of each other on the photosensitive layer. 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, thereby shortening the vacuuming time and preventing the collapse of minute dots during exposure due to poor adhesion. That is. As a method for applying the mat layer, a method of thermally fusing powdered solid powder described in JP-A-55-12974, and a method of spraying polymer-containing water described in JP-A-58-182636, are used. And drying methods,
Either method can be used. The mat layer is desirably composed of a substance which is dissolved in an aqueous developer substantially free of an organic solvent or which can be removed thereby.

A photosensitive lithographic printing plate having a photosensitive composition layer applied and dried on a roughened aluminum plate is exposed to an image and then developed with an aqueous alkali solution-based developer to produce a negative image with respect to the original image. A relief image is obtained. Light sources suitable for exposure include a carbon arc lamp, a mercury lamp, a xenon lamp, a metal halide lamp, a strobe, an ultraviolet laser beam, and the like. Examples of the alkaline aqueous solution developer used for developing the photosensitive lithographic printing plate include:
JP-A-51-77401, JP-A-51-80228, JP-A-53-44202 and JP-A-55-52054, which have a developer having a pH of 8 to 13,
It is preferable that water contains 75% by weight or more. If necessary, an organic solvent (benzyl alcohol, ethylene glycol monophenyl ether) having a solubility in water of 10% by weight or less at room temperature, an alkali agent (triethanolamine, diethanolamine, monoethanolamine, sodium phosphate, sodium carbonate), anionic surface activity Agents (aromatic sulfonate, dialkyl sulfosuccinate, alkyl naphthalene sulfonate, fatty acid salt, alkyl sulfate ester salt), nonionic surfactant (polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene poly) Oxypropylene block polymer), antifouling agent (sodium sulfite,
Sulfopyrazolone sodium salt) and water softeners (ethylenediaminetetraacetic acid tetrasodium salt, nitrilotriacetic acid trisodium salt) can be added.

[0025]

The photosensitive lithographic printing plate of the present invention can be alkali-developed and has high inking property and printing durability.

Next, the present invention will be described with reference to examples.

【Example】

Example 1 An aluminum plate was immersed in an aqueous sodium phosphate solution and degreased.
After polishing with a brush, electrolytic etching, 0.1 g / m ² etching with an aqueous sodium hydroxide solution, and neutralization with sulfuric acid. Then, it was anodized in sulfuric acid, and was further immersed in an aqueous solution of sodium silicate for hydrophilization. After dissolving the following photosensitive composition in the following solvent on this hydrophilized aluminum plate and applying it with a Wheeler coater, it is dried in an oven at 100 ° C. for 80 seconds and air-coated with a water-soluble resin matting agent. And dried naturally to obtain a photosensitive lithographic printing plate. The coated amount of the photosensitive layer after drying was 1.5 g / m ² . Photosensitive composition Diazo resin-1 0.35 g Diazo resin-2 0.15 g Binder-1 5.00 g Stylite HS-2 0.10 g Victoria Pure Blue BOH 0.15 g Tricresyl Phosphate 0.50 g Dipicolinic acid 0.20 g FC-430 (surfactant manufactured by 3M) 0.05 g Solvent 1-methoxy-2-propanol 25.00 g Methyl lactate 12.00 g Methanol 30.00 g Methyl ethyl ketone 30.00 g Water 3. 00g

Diazo resin-1 is disclosed in JP-A-59-7834.
It is a hexafluorophosphate of a condensate of p-diazodiphenylamine and paraformaldehyde described in Synthesis Example 1 of JP-A No. 0. Diazo resin-2 is a dodecylbenzenesulfonate of a condensate of p-diazophenylamine and paraformaldehyde. Binder-1 is 2-hydroxyethyl methacrylate / acrylonitrile / methyl methacrylate / methacrylic acid copolymer (weight ratio 5
0/20/26/4, average molecular weight 75,000, acid value 0.4
meq / g) is a water-insoluble, alkaline water-soluble film-forming polymer. Stylite HS-2 (manufactured by Daido Industry Co., Ltd.)
Is a polymer compound having higher oil sensitivity than the binder, and is a copolymer of styrene / mono-4-methyl-2-pentyl maleate = 50/50 (molar ratio), and has an average molecular weight of about 100. , 000. The photosensitive lithographic printing plate is image-exposed, and DN-3C (alkaline aqueous solution developer manufactured by Fuji Photo Film Co., Ltd.) is made 1: 1 with water by 800H (automatic developing machine manufactured by Fuji Photo Film Co., Ltd.). The diluted solution was developed, and a solution prepared by diluting FN-2 (a gum solution manufactured by Fuji Photo Film Co., Ltd.) 1: 1 with water was applied and dried.
The next day, this printing plate was mounted on a Harris Aurelia printing machine (manufactured by Harris Corporation) and printed at a speed of 6,000 sheets / hour.
A printed matter having a sufficient ink density was obtained on the first sheet. (In the following Examples and Comparative Examples, this is referred to as the sixth inking property.) Further, 100,000 sheets of printed matter having a sufficient ink density were obtained. (In the following Examples and Comparative Examples, this was
Described as 10,000 sheets. )

Examples 2 to 13 Using the solvent of Example 1 and various diazo resins and binders, printing plates were prepared in the same manner as in Example 1, and the inking property and printing durability were examined. . Table 1 shows the results.

[Table 1] <Example 1> Example Diazo resin a Diazo resin b Binder Bonding property Printing durability Type Amount (g) Type Amount (g) Type Amount (g) (Sheet number) (Million sheets) 2-1 0.05 -2 0.45 -1 5.00 693 -1 0.25 -2 0.25 -1 5.00 610 4 -1 0.35 -2 0.15 -1 5.00 6 10 5 -1 0.45 -2 0.05 -1 5.00 69 6 -1 0.35- 3 0.15 -1 5.00 6 10 7 -1 0.35 -4 0.15 -1 5.00 6 10 8 -5 0.35 -4 0.15 -1 5.00 6 10 9 -1 0.35 -2 0.15 -2 5.00 6 10 10 -1 0.35 -6 0.15 −2 5.00 6 10 11 −7 0.35 −6 0.15 −2 5.00 6 10 12 −1 0.35 −8 0.15 −2 5.00 6 10 13 −9 0.35 −8 0.15 −2 5.00 610

The diazo resin-3 is a dibutylnaphthalenesulfonic acid salt of a condensate of p-diazodiphenylamine and formaldehyde. Diazo resin-4 is an octylnaphthalene sulfonate of a condensate of p-diazodiphenylamine and formaldehyde. Diazo resin-5
Is a tetrafluoroborate salt of a condensate of p-diazodiphenylamine and formaldehyde. Diazo resin-6 is a dodecylbenzene sulfonate of a condensate of phenoxyacetic acid / p-diazodiphenylamine (cocondensation ratio 50/50) and formaldehyde. Diazo resin-
7 is a hexafluorophosphate salt of a condensate of phenoxyacetic acid / p-diazodiphenylamine (cocondensation ratio 50/50) and formaldehyde. Diazo resin-8 is
4,4'-bis (methoxy) diphenyl ether / 3-
It is a mesitylene sulfonic acid salt of methoxydiphenylamine-4-diazonium (cocondensation ratio 50/50). The diazo resin-9 is a sulfate of 4,4'-bis (methoxy) diphenyl ether / 3-methoxydiphenylamine-4-diazonium (cocondensation ratio 50/50). Binder-2 was 2-hydroxyethyl methacrylate / acrylonitrile / ethyl methacrylate / methacrylic acid copolymer (weight ratio 45/15/36/4, average molecular weight 120
000, acid content 0.4 meq / g).

Examples 14 to 22 Printing plates were prepared in the same manner as in Example 1 using the diazo resin and the binder of Example 1 and various solvents, and the inking property and printing durability were examined. Table 2 shows the results.

<Table 2> 1-Methoxy-2-propanol Ink- coating Printing durability Examples (g) Other solvents (g) (the first sheet) (ten thousand sheets) 14 10 Methyl lactate 12 8 10 Methanol 30 Methyl ethyl ketone 45 Water 3 15 40 Methyl lactate 12 6 10 Methanol 20 Methyl ethyl ketone 25 Water 3 16 70 Methanol 10 6 10 Methyl ethyl ketone 17 Water 3 17 25 Methyl lactate 12 6 10 Methanol 30 Ethylene chloride 30 Water 3 18 25 Methyl lactate 12 6 10 Methanol 30 Tetrahydrofuran 30 water 3 1925 methanol 30 610 methyl ethyl ketone 40 diethylene glycol monomethyl ether 2 water 3 20 25 methanol 30 610 methyl ethyl ketone 40 γ-butyrolactone 2 water 3 2125 methanol 30 610 methyl ethyl With ketone 40 dimethyl sulfoxide 2 water 3 22 25 methanol 30 6 10 Methyl ethyl ketone 40 dimethylformamide 2 binding agent of water 3 Comparative Examples 1-8 Example 1, as in Example 1 by using a diazo resin and a solvent composition other than the present invention Similarly, a printing plate was prepared, and its inking property and printing durability were examined. Table 3 shows the results.

<Table 3> Comparative Example Diazo resin Solvent composition Ink-coating Printing durability (g) (g) (sheets) (10,000 sheets) 1-10.5 1-methoxy-2-fluorophenol 25 406 Lactic acid Methyl 12 methanol 30 methyl ethyl ketone 30 water 32-2 0.5 1-methoxy-2-fluoroethanol 25 209 methyl lactate 12 methanol 30 methyl ethyl ketone 30 water 33-3 0.5 1-methoxy-2-fluoroethanol 25 226 methyl methyl lactate 12 methanol 30 Methyl ethyl ketone 30 water 34 -1 0.35 methyl cellosolve 37 358 -2 0.15 methanol 30 methyl ethyl ketone 30 water 35 -1 0.35 methyl lactate 12 308 -2 0.15 methyl cellosolve 25 methanol 30 methyl ethyl ketone 30 water 3 6 -1 0.35 1-methoxy -2-Fluorophenol 3 57-7-2 0.15 Methyl lactate 12 Methanol 40 Methyl ethyl ketone 42 Water 37 -1 0.35 Methyl lactate 12 257 -2 0.15 Methanol 43 Methyl ethyl ketone 42 Water 38 -10.35 γ-butyrolactone 12 257 -2 0.15 Methanol 43 Methyl ethyl ketone 42 Water 3. As is clear from the above examples, it can be understood that the photosensitive lithographic printing plate manufactured according to the present invention has excellent inking property and printing durability.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03F 7/00 503 G03F 7/004 G03F 7/021 G03F 7/033

Claims (1)

(57) [Claims] 1. A diazo resin a whose counter anion is an inorganic acid anion or an aliphatic organic acid anion having 3 or less carbon atoms.
And a negative photosensitive composition containing a diazo resin b having a counter anion of an aliphatic or aromatic organic acid anion having 6 or more carbon atoms and a binder, 1-methoxy-2-propanol in an amount of 10 to 100% by weight. %. A method for producing a photosensitive lithographic printing plate, comprising dissolving in a coating solvent containing 0.1% by weight, applying to a support having a hydrophilic surface, and drying.