JPH08258440A - Support for lithographic printing plate and manufacture thereof and photosensitive lithographic printing plate - Google Patents

Abstract

PURPOSE: To obtain a support for a lithographic printing plate which has good blanket scumming and plate wear, can wring water during printing, has wide water allowance for good tone rendering by forming two kinds of average irregularities with different surface roughness overlappingly. CONSTITUTION: A support for a photosensitive lithographic printing plate is formed by overlapping average irregularities of 0.5-5μm and 50-300nm. The support is prepared by a process in which the surface of an aluminum plate is subjected to electrochemical surface roughening treatment in an aqueous solution mainly containing nitric acid, to chemical etching treatment in an aqueous solution of acid or alkali or to electrochemical etching treatment in an aqueous solution of neutral salt, and then to electrochemical surface roughening treatment in an aqueous solution mainly containing hydrochloric acid. A photosensitive layer containing a photosensitive composition is applied on the support for the lithographic printing plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support for a lithographic printing plate, a method for producing the same, and a photosensitive lithographic printing plate.
The present invention relates to a lithographic printing plate support having good printing durability, capable of suppressing blanket contamination, and having good dot gain, a method for producing the same, and a photosensitive lithographic printing plate.

[0002]

BACKGROUND OF THE INVENTION Conventionally, a support used for a photosensitive lithographic printing plate is required to have excellent hydrophilicity, water retention, adhesiveness to a photosensitive layer, etc. from the viewpoint of printability. Therefore, a support obtained by hydrophilically treating an aluminum plate that has been roughened and anodized is usually used.

[0003]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 6-171260 discloses a technique of performing an electrochemical graining treatment with an aqueous hydrochloric acid solution and an electrochemical graining treatment with an aqueous nitric acid solution in addition to the mechanical graining treatment. Japanese Unexamined Patent Publication No. 3-104694 discloses a technique for forming a rough surface having planographic unevenness of 0.1 μm or less by electrochemical roughening treatment with a nitric acid aqueous solution and chemical etching. Japanese Unexamined Patent Publication No. 57-16918 discloses a chemical etching treatment, and Japanese Unexamined Patent Publication No. 54-62132 discloses a technique of performing an electrochemical treatment with an aqueous neutral salt solution.

[0004]

It is an object of the present invention to provide a lithographic printing plate support having good blanket stains and excellent printing durability, water squeezed during printing, a wide water width, and good tone reproduction, and a method for producing the same. It is to provide a photosensitive lithographic printing plate by coating a photosensitive layer on the support.

[0005]

The above object of the present invention is 0.5 to 5 μm.
And the average unevenness of 50 to 300 nm are formed to overlap each other, the support for a lithographic printing plate and the surface of the aluminum plate are sequentially formed. A) Electrochemically in an aqueous solution containing nitric acid as a main component. Roughening treatment, b) chemical etching treatment with acid or alkali aqueous solution or electrochemical etching treatment in neutral salt aqueous solution, and c) electrochemical roughening treatment in aqueous solution mainly containing hydrochloric acid A method for producing a support for a lithographic printing plate, comprising: an average unevenness of 0.5 to 5 μm; and 50 to 300 nm.
The photosensitive lithographic printing plate is formed by coating a photosensitive layer containing a photosensitive composition on a support for a lithographic printing plate which is formed by overlapping the average irregularities.

[0006]

[Function] The electrochemical roughening with nitric acid aqueous solution had the advantage of good tone reproduction and printing durability, but the stains on the blanket were poor, and the electrochemical roughening with hydrochloric acid aqueous solution did not produce good results during printing. Although the water was squeezed and the blanket was dirty, the printing durability was poor.

Therefore, by combining the electrochemical surface roughening treatment with the nitric acid aqueous solution and the electrochemical surface roughening treatment with the hydrochloric acid aqueous solution, the above problems are solved and water is squeezed during printing, tone reproduction, printing durability, and blanket stains. It was possible to obtain a good lithographic printing plate support.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail below. The aluminum support used in the present invention 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, or nickel.

The aluminum support is preferably subjected to a degreasing treatment in order to remove rolling oil on the aluminum surface prior to roughening. As degreasing treatment, trichlene,
A degreasing treatment using a solvent such as thinner, an emulsion degreasing treatment using an emulsion such as kesilon and triethanol, and the like are used. In addition, an alkaline aqueous solution such as caustic soda can be used for the degreasing treatment. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, it is possible to remove stains and oxide films which cannot be removed only by the above degreasing treatment.

The graining treatment method performed to improve the adhesion to the photosensitive layer and to improve the water retention property is as follows.
There are a so-called mechanical surface-roughening method for mechanically roughening the surface and a so-called electrochemical surface-roughening method for electrochemically roughening the surface. Examples of the mechanical surface roughening method include ball polishing, brush polishing, blast polishing, and buff polishing. The electrochemical surface roughening method includes, for example, a method of electrolytically treating the support with an alternating current or a direct current in an electrolytic solution containing hydrochloric acid, nitric acid, or the like. One of these
One or a combination of two or more methods makes it possible to grain the support. (A) In the present invention, an aluminum plate is first electrochemically treated in an aqueous solution containing nitric acid as a main component. Electrochemical surface roughening treatment in an aqueous solution containing nitric acid means electrochemical surface roughening in an aqueous solution containing nitric acid by applying direct current or alternating current between the aluminum plate and the facing electrode. It means processing. The concentration of nitrate compounds is
0.01 to 10% by weight is preferable. Preferred compounds include aluminum nitrate, nitric acid, sodium nitrate, ammonium nitrate and the like, and these are used alone or in combination. Further, other compounds containing nitrate ions can be combined. Further, it is preferable to mix the nitric acid electrolytic solution with an aluminum salt in an amount of 20 to 150 g / l. The temperature of the electrolytic solution containing nitric acid is 1
0-50 degreeC is preferable and 15-45 degreeC is more preferable.

In the method of electrochemically roughening the surface in an aqueous solution containing nitric acid as an alternating current, the current density is preferably 10 to 150 A / dm ² , and 20 to 100 A / dm ^2.
A / dm ² is more preferable. Electricity is 10 to 20000
c / dm ^2, preferably 200~5000c / dm ^2. (B) Next, it is chemically etched in an acid or alkali aqueous solution or electrochemically etched in a neutral salt aqueous solution. For chemical etching treatment in the above-mentioned acid or alkali aqueous solution, JP-A-57-1691 is used.
As disclosed in JP-A-8, an aqueous acid solution such as hydrofluoric acid, fluorinated zirconic acid, phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, or sodium hydroxide, potassium hydroxide, sodium triphosphate,
An alkaline aqueous solution of sodium aluminate, sodium acidate, sodium carbonate or the like is used. These silicic acid or alkaline aqueous solutions may be used either individually or in combination of two or more. The etching amount is 0.
It is preferable to etch aluminum corresponding to ¹ to 20 g / m ² . In order to perform etching within the above etching amount, the concentration of acid or alkali is 0.05 to
40%, liquid temperature 40 ~ 100 ℃, processing time 5 ~ 300
Select from the range of seconds appropriately.

When the aluminum surface is chemically etched with an alkaline aqueous solution, insoluble matter, that is, smut, is formed on the surface. Phosphoric acid, sulfuric acid, nitric acid, chromic acid, etc. can be removed from this smut by washing with a mixture thereof. The electrochemically treated aluminum surface is preferably a clean surface without smut, but this can be omitted when the electrolytic solution is an acid and has a smut removing effect.

The electrochemical etching treatment in the neutral salt aqueous solution means that aluminum is added to an aqueous solution containing an alkali metal salt of an inorganic acid or an organic acid, as disclosed in JP-A-54-62132. This means immersing the plate for DC cathodic electrolysis. The neutral salt aqueous solution is preferably an aqueous solution mainly containing sodium chloride, sodium nitrate, sodium sulfate, etc., and the pH is preferably 4 to 11.
The concentration of these compounds can be adopted from 5 g / l to a saturated concentration, and the current density is 0.1 to 100 A / dm ^2.
Is preferred. The electrolytic treatment time is preferably in the range of 1 to 90 seconds, and the liquid temperature is preferably 40 to 70 ° C. (C) Further, it is electrochemically treated in an aqueous solution mainly containing hydrochloric acid. The electrochemical treatment in an aqueous solution containing hydrochloric acid as a main means that electrochemical roughening treatment is performed by applying an alternating current between an electrode facing an aluminum plate in an aqueous solution containing hydrochloric acid. . The concentration of hydrochloric acid compound is 0.0
1 to 10% by weight is preferable. Preferred compounds contain a chloride ion consisting of aluminum chloride, hydrochloric acid, sodium chloride, ammonium chloride or magnesium chloride, which may be used alone or in combination. In addition, it may be combined with other compounds containing a chloride ion. Further, add 20% aluminum salt to the hydrochloric acid electrolyte.
Mixing in amounts of up to 150 g / l is preferred. The temperature of the electrolytic solution containing hydrochloric acid as a main component is 10 to 50 ° C, preferably 15 to 45 ° C.

In the method of electrochemical surface roughening treatment using an alternating voltage in an aqueous solution containing hydrochloric acid as a main component, the current density is 10 to 150 A / dm ² , preferably 10 to 10 A / dm ² .
It is 0 A / dm ² . Electricity is 1 to 5000c / d
m ² , preferably 1-1000 c / dm ² .

The aluminum plate electrochemically surface-roughened in an aqueous solution containing hydrochloric acid is desmutted and / or mildly treated in an acid or alkali aqueous solution for the purpose of removing smut components formed on the surface of the aluminum plate. Etching treatment is performed. Specific examples of the acid or alkali include hydrofluoric acid, fluorozirconic acid, phosphoric acid, sulfuric acid, hydrochloric acid,
There are acids such as nitric acid and alkalis such as sodium hydroxide, potassium hydroxide, tribasic sodium phosphate, sodium aluminate, sodium silicate and sodium carbonate. These acid or alkali aqueous solutions can be used alone or in combination of two or more. Etching is 0.
It is preferable to etch aluminum corresponding to 01 to ² g / m ² . To perform such etching, the concentration of acid or alkali is 0.05
-40%, liquid temperature 40-100 ° C, treatment time 5-30
The time is appropriately selected from the range of 0 seconds.

As such a light etching process,
Electrochemical treatment can also be performed by applying a DC voltage to the aluminum plate as a cathode in a neutral salt aqueous solution.

When the aluminum surface is lightly etched, insoluble matter, that is, smut, is formed on the surface. Phosphoric acid, sulfuric acid, nitric acid, chromic acid, etc. can be removed from this smut by washing with a mixture thereof.

The support preferably used in the present invention may be subjected to a pore-sealing treatment after the anodizing treatment. Examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, dichromate aqueous solution treatment, nitrite treatment, and ammonium acetate treatment.

Further, the support preferably used in the present invention may be provided with a hydrophilic undercoat layer. Examples of the hydrophilic undercoat layer include alkali metal silicates described in U.S. Pat. No. 3,181,461, hydrophilic celluloses described in U.S. Pat. No. 1,860,426, JP-A-60- 1494
91 and 63-165183, amino acids and salts thereof, hydroxyl group-containing amines and salts thereof described in JP-A-60-232998, JP-A-62-
Phosphates described in Japanese Patent No. 19494, JP-A-59-101
Examples thereof include polymer compounds containing a monomer unit having a sulfo group described in Japanese Patent No. 651.

Next, a photosensitive layer containing the photosensitive composition is applied onto the surface-treated support to obtain a photosensitive lithographic printing plate preferably used in the present invention. The photosensitive substance used in this photosensitive layer is not particularly limited, and various substances usually used in photosensitive lithographic printing plates can be used. Hereinafter, this point will be described.

(Photosensitive Layer) The photosensitive lithographic printing plate of the present invention can be obtained by coating the surface-treated support of the present invention with a photosensitive layer of a photosensitive composition. The photosensitive substance used in this photosensitive layer is not particularly limited as long as it is an o-quinonediazide compound when a positive photosensitive lithographic printing plate is to be obtained, and usually, for example, various kinds of compounds such as those described below are used. Stuff used.

(Photosensitive composition containing o-quinonediazide compound) In the photosensitive composition containing an o-quinonediazide compound used, an o-quinonediazide compound and an alkali-soluble resin are used in combination. Examples of the o-quinonediazide compound include ester compounds of o-naphthoquinonediazidesulfonic acid and a polycondensation resin of phenols and aldehydes or ketones.

Examples of the phenols include monohydric phenols such as phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, carvacrol and thymol, and dihydric compounds such as catechol, resorcinol and hydroquinone. Examples include trihydric phenols such as phenol, pyrogallol, and phloroglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred of these are formaldehyde and benzaldehyde. Examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol / formaldehyde resin, m-cresol / formaldehyde resin, m- and p-mixed cresol / formaldehyde resin, resorcin / benzaldehyde resin, pyrogallol / acetone resin. To be OH of phenols of the o-naphthoquinonediazide compound
The condensation rate of o-naphthoquinonediazide sulfonic acid with respect to the group (reaction rate with respect to one OH group) is preferably 15 to 80%, and more preferably 20 to 45%.

Further, as the o-quinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be used. That is, for example, 1, 2
-Benzoquinone diazide sulfonate, 1,2-
Known 1,2-naphthoquinone diazide sulfonic acid ester, 1,2-benzoquinone diazide sulfonic acid amide, 1,2-naphthoquinone diazide sulfonic acid amide, etc.
Quinone diazide compounds, more specifically J. Kosar "Light-Sensitive Systems" (Light-Sensitive System)
ems) pp. 339-352 (1965), John.
Willie & Sons (John Willey &
Sons, Inc. (New York) and W. S. De Forest, "Photoresist", Volume 50 (1975), McGraw H
ill) (New York) 1,2-
Benzoquinonediazide-4-sulfonic acid phenyl ester, 1,2,1 ', 2'-di- (benzoquinonediazide-4-sulfonyl) -dihydroxybiphenyl, 1,2
-Benzoquinonediazide-4- (N-ethyl-M-β-
Naphthyl) -sulfonamide, 1,2-naphthoquinonediazide-5-sulfonic acid cyclohexyl ester, 1-
(1,2-naphthoquinonediazide-5-sulfonyl)-
3,5-Dimethylpyrazole, 1,2-naphthoquinonediazide-5-sulfone-4'-hydroxydiphenyl-
4'-azo-β-naphthol-ester, N, N-di-
(1,2-naphthoquinonediazide-5-sulfonyl)-
Aniline, 2 '-(1,2-naphthoquinonediazide-5
-Sulfonyloxy) -1-hydroxy-anthraquinone, 1,2-naphthoquinonediazide-5-sulfone-
2,4-dihydroxybenzophenone ester, 1,2
-Naphthoquinonodiazide-5-sulfonic acid-2,3,4
-Trihydroxybenzophenone ester, a condensate of 2 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mol of 4,4'-diaminobenzophenone,
Condensate of 2 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mol of 4,4′-dihydroxy-1,1′-diphenylsulfone, 1 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride Examples thereof include a 1,2-quinonediazide compound such as a condensate of 1 mol of purpurogallin and 1,2-naphthoquinonediazide-5- (N-dihydroabietyl) -sulfonamide. In addition, Japanese Examined Patent Publications No. 37-1953 and 37-3627
Nos. 37-13109, 40-26126, 40-3801, 45-5604, 45-27.
No. 345, No. 51-13013, JP-A-48-965.
The 1,2-quinonediazide compounds described in JP-A No. 75, 48-63802 and 48-63803 can also be mentioned.

Of the above o-quinonediazide compounds,
An o-quinone diazide ester compound obtained by reacting 1,2-benzoquinone diazide sulfonyl chloride or 1,2-naphthoquinone diazide sulfonyl chloride with pyrogallol-acetone condensation resin or 2,3,4-trihydroxybenzophenone is particularly preferable. As the o-quinonediazide compound used in the present invention, the above compounds may be used alone or in combination of two or more kinds. The proportion of the o-quinonediazide compound in the photosensitive composition is preferably 6 to 60% by weight, and particularly preferably 10 to 50% by weight.

(Diazo Compound) On the other hand, when a negative photosensitive lithographic printing plate is to be obtained, a known photosensitive composition containing a diazo compound may be used.

The diazo compound in the photosensitive composition is, for example, preferably a diazo resin represented by a condensation product of an aromatic diazonium salt and formaldehyde or acetaldehyde. Particularly preferably, the reaction product of a salt of a condensate of p-diazophenylamine with formaldehyde or acetaldehyde, such as hexafluoroborophosphate, tetrafluoroborate, perchlorate or periodate, and the condensate is formed. Examples thereof include diazo resin inorganic salt which is a product, and diazo resin organic salt which is a reaction product 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, but preferably, a monomer having an aromatic hydroxyl group as described in JP-A-54-98613, such as N- (4 -Hydroxyphenyl) acrylamide, N-
(4-hydroxyphenyl) methacrylamide, o-,
Copolymers of m- or p-hydroxystyrene, o-, m-, or p-hydroxyphenyl methacrylate with other monomers, described in U.S. Pat. No. 4,123,276. Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as main repeating units, such as shellac,
Natural resins such as rosin, polyvinyl alcohol, linear polyurethane resins as described in US Pat. No. 3,751,257, phthalated resins of polyvinyl alcohol, epoxy resins condensed from bisphenol A and epichlorohydrin , Cellulose acetate, cellulose acetate phthalate, and other cellulose derivatives.

In addition to the above, the following photosensitive composition may be used.

1) Photocrosslinking-type photosensitive resin composition The photosensitive component in the photocrosslinking-type photosensitive resin composition is composed of a photosensitive resin having an unsaturated double bond in the molecule. For example, US Pat. No. 030,208, No. 3,4
35,237 and 3,622,320, and JP-A-59-42684 and JP-B-6-76.
No. 442, JP-A-5-85562, etc.

[0031]

Embedded image

Examples thereof include a photosensitive resin containing, and a polyvinyl cinnamate having a photosensitive group on the side chain of the polymer.

2) Photopolymerizable Photosensitive Resin Composition A photopolymerizable composition containing an addition polymerizable unsaturated compound, which comprises a monomer having a double bond or a monomer having a double bond. A typical example of such a composition comprising a polymer binder is disclosed in, for example, US Pat. No. 2,760,8.
No. 63 and No. 2,791,504.

As an example, a composition containing methylmethacrylate, a composition containing methylmethacrylate and polymethylmethacrylate, a composition containing methylmethacrylate, polymethylmethacrylate and polyethyleneglycolmethacrylate monomers, methylmethacrylate, an alkyd resin. A photopolymerizable composition such as a composition containing a polyethylene glycol dimethacrylate monomer is used.
This photopolymerization type photosensitive resin composition includes a photopolymerization initiator usually known in this technical field (for example, benzoin derivative such as benzoin methyl ether, benzophenone derivative such as benzophenone, thioxanthone derivative, anthraquinone derivative, acridone derivative, etc. ) Is added.

(Alkali-Soluble Resin) As the alkali-soluble resin, a novolac resin, a vinyl polymer having a phenolic hydroxyl group, a condensation of a polyhydric phenol and an aldehyde or ketone described in JP-A-55-57841. Resin etc. are mentioned.

Examples of the novolac resin used in the present invention include phenol / formaldehyde resin, cresol / formaldehyde resin, JP-A-55-57841.
Phenol-cresol-formaldehyde copolymer resin as described in JP-A-55-127
Examples thereof include copolymer resins of p-substituted phenol and phenol or cresol and formaldehyde as described in Japanese Patent No. 553.

The novolak resin preferably has a number average molecular weight Mn of 3.00 × (polystyrene standard).
10 ^{2 to} 7.50 × 10 ³ , and the weight average molecular weight Mw is 1.
00 × 10 ^{3 to} 3.00 × 10 ⁴ , more preferably Mn
Is 5.00 × 10 ^{2 to} 4.00 × 10 ³ , and Mw is 3.0.
It is 0 × 10 ^{3 to} 2.00 × 10 ⁴ . The above novolak resins may be used alone or in combination of two or more.

The proportion of the novolak resin in the photosensitive composition is preferably 5 to 95% by weight. Further, the vinyl copolymer having a phenolic hydroxyl group preferably used in the present invention is a polymer having a unit having the phenolic hydroxyl group in its molecular structure, and has the following general formula [I]
Polymers containing at least one structural unit of [V] are preferred.

[0039]

Embedded image

[In the formula, 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 or 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, preferably a hydrogen atom. A represents an optionally substituted alkylene group connecting a nitrogen atom or an oxygen atom and an aromatic carbon atom, m represents an integer of 0 to 10, and B represents
Represents a phenylene group which may have a substituent or a naphthylene group which may have a substituent. ]

As the polymer used in the present invention, those having a copolymer type structure are preferable, and the above-mentioned general formula [I] is used.
~ Examples of the monomer unit that can be used in combination with the structural unit represented by the general formula [V] include ethylenically unsaturated offylenes such as ethylene, propylene, isobutylene, butadiene, and isoprene, for example, styrene and α-. Styrenes such as methylstyrene, p-methylstyrene and p-chlorostyrene, acrylic acids such as acrylic acid and methacrylic acid, and unsaturated aliphatic dicarboxylic acids such as itacone, maleic acid and maleic anhydride,
For example, methyl acrylate, ethyl acrylate, -n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, Α such as ethyl methacrylate
-Esters of methylene aliphatic monocarboxylic acid, for example, nitriles such as acrylonitrile, methacrylonitrile, etc., amides such as acrylamide, such as acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, etc. Anilides such as vinyl acetate, vinyl propionate,
Vinyl esters such as vinyl benzoate and vinyl acetate,
For example, methyl vinyl ether, ethyl vinyl ether,
Isobutyl vinyl ether, vinyl ethers such as β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as 1-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1 -Dimethoxycarbonylethylene, ethylene derivatives such as 1-methyl-1-nitroethylene, such as N-vinylpyrrole, N
There are N-vinyl type monomers such as -vinylcarbazole, N-vinylindole, N-vinylpyrrolidene and N-vinylpyrrolidone. These vinyl-based monomers are present in the polymer compound with a structure in which the unsaturated double bond is cleaved.

Of the above-mentioned monomers, aliphatic monocarboxylic acid esters and nitriles exhibit excellent performance for the purpose of the present invention and are preferred. These monomers may be bound to the polymer used in the present invention in either a block or random state.

The proportion of the vinyl polymer used in the present invention in the photosensitive composition is preferably 0.5 to 70% by weight. As the vinyl polymer, the above polymers may be used alone or in combination of two or more kinds.
It can also be used in combination with other polymer compounds.

(Organic Acid / Inorganic Acid / Anhydride) The photosensitive composition of the present invention may contain an organic acid / inorganic acid / anhydride. Examples of the acid used in the present invention include organic acids described in JP-A No. 60-88942 and Japanese Patent Application No. 63-293107, and "Chemical Handbook New Edition" edited by The Chemical Society of Japan, No. 92-158. The inorganic acids described on the page can be mentioned.
Examples of organic acids include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, mesitylenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, benzensulfonic acid,
Sulfonic acids such as m-benzenedisulfonic acid, sulfinic acids such as p-toluenesulfinic acid, benzylsulfinic acid and methanesulfinic acid, phosphonic acids such as phenylphosphonic acid, methylphosphonic acid and chloromethylphosphonic acid,
Aliphatic monocarboxylic 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 cyclohexanecarboxylic acid, benzoic acid, o-, m-, p -Hydroxybenzoic acid,
o-, m-, p-methoxybenzoic acid, o-, m-, p-
Aromatic monocarboxylic acids such as methylbenzoic acid, 3,5-dihydroxybenzoic acid, phloroglysin carboxylic acid, gallic acid and 3,5-dimethylbenzoic acid can be mentioned. 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, malic acid, tetrahydro Phthalic acid, 1,1-cyclobutanedicarboxylic acid,
1,1-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3
Examples thereof include alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid.

Among the above organic acids, more preferable one is p
-Toluenesulfonic acid, dodecylbenzenesulfonic acid,
Examples include sulfonic acid such as mesitylenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, benzensulfonic acid, and m-benzenedisulfonic acid, cis-1,2-cyclohexanedicarboxylic acid, and syringic acid.

Examples of inorganic acids include nitric acid, sulfuric acid, hydrochloric acid,
Examples thereof include silicic acid and phosphoric acid, with sulfuric acid and phosphoric acid being more preferable.

When an acid anhydride is used, the type of acid anhydride is also arbitrary, and those derived from aliphatic / aromatic monocarboxylic acids such as acetic anhydride, propionic anhydride, benzoic anhydride, and succinic anhydride. , Maleic anhydride, glutaric anhydride, phthalic anhydride, and the like, and the like derived from aliphatic / aromatic dicarboxylic acids. Preferred acid anhydrides are glutaric anhydride and phthalic anhydride. These compounds may be used alone or in combination of two or more.

The content of these acids is generally 0.05 to 5% by weight, preferably 0.1 to 3% by weight, based on the total solid content of the entire photosensitive composition. Is.

(Surfactant) The photosensitive composition of the present invention may contain a surfactant. As the surfactant, an amphoteric surfactant, an anionic surfactant, a cationic surfactant,
Nonionic surfactants, fluorine-based surfactants and the like can be mentioned.

Examples of the amphoteric surfactant include lauryl dimethylamine oxide, lauryl carboxymethyl hydroxyethyl, imidazolinium betaine and the like.

As the anionic surfactant, a fatty acid salt,
Alkyl sulfate ester salt, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl sulfosuccinate, alkyl diphenyl ether disulfonate, alkyl phosphate, polyoxyethylene alkyl sulfate ester salt, polyoxyethylene alkyl allyl sulfate salt, naphthalene Sulfonic acid formalin condensate,
Examples include polyoxyethylene alkyl phosphate ester.

Examples of the cationic surfactant include alkylamine salt, quaternary ammonium salt, alkylbetaine and the like.

As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene derivative, oxyethylene / oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene. There are sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, alkylalkanolamide and the like.

Examples of the fluorinated surfactants include copolymers of acrylates or methacrylates containing a fluoroaliphatic group and (polyoxyalkylene) acrylates or (polyoxyalkylene) methacrylates. These compounds may be used alone or in combination of two or more. Particularly preferably FC-430
(Sumitomo 3M Co., Ltd.) Fluorine-based polyethylene glycol # -2000 (Kanto Chemical Co., Inc.). The proportion in the photosensitive composition is preferably 0.01 to 10% by weight, more preferably 0.01 to 5% by weight.

(Printout Material) A printout material capable of forming a visible image upon exposure can be added to the photosensitive composition. The printout material comprises an organic dye which changes its color tone by interacting with a compound which forms an acid or a free radical upon exposure. Examples of the compound which forms an acid or a free radical upon exposure include, for example, JP-A-50- O described in Japanese Patent No. 36209
-Naphthoquinonediazide-4-sulfonic acid halogenide,
An ester compound or amide compound of o-naphthoquinonediazide-4-sulfonic acid chloride and an electron-withdrawing substituent phenol or aniline acid described in JP-A-53-36223, JP-A-55-
Examples thereof include halomethylvinyloxadiazole compounds and diazonium salts described in JP-A 77742, JP-A-57-148784 and the like.

(Compound which produces an acid or a free radical upon exposure to light) As a compound which can be used in the photosensitive composition of the present invention to produce an acid or a free radical upon exposure, for example, a halomethyloxadiazole compound, A halomethyl-s-triazine compound or the like is used.

The halomethyloxadiazole compound is
Oxadiazoles are compounds having a halomethyl group, preferably a trichloromethyl group.

These compounds are known, for example, Japanese Patent Publication Nos. 57-6096 and 61-51788,
Japanese Patent Publication No. 1-28369, JP-A-60-13853
No. 9, JP 60-177340, and JP 60-24.
It is described in Japanese Patent No. 1049.

The halomethyl-s-triazine compound is a compound having one or more halomethyl groups on the s-triazine ring, preferably a trichloromethyl group.

In the photosensitive composition of the present invention, the addition amount of the compound which forms an acid or a free radical upon exposure to light is 0.
01 to 10% by weight is preferable, and 0.1 is more preferable.
˜30 wt%, and particularly preferably 0.2 to 3 wt%.

These compounds can be used alone or in admixture of two or more.

(Dye) A dye may be further used in the photosensitive composition of the present invention. The dye is used for the purpose of obtaining a visible image by exposure (exposed 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, "the color tone changes" includes both a change from colorless to a color tone, and a change from a colored to a colorless or 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 (manufactured by Orient Chemical Industry Co., Ltd.), patent pure blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), crystal violet,
Brilliant Green, Ethyl Violet, Methyl Violet, Methyl Green, Erythrosin B, Pesic Fuchsin, Malachite Green, Oil Red, m
-Cresol purple, rhodamine B, auramine,
Triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based, or anthraquinone-based dyes such as 4-p-diethylaminophenyliminaquinoquine and cyano-p-diethylaminophenylacetanilide are colored to colorless. Alternatively, it may be mentioned as an example of a color changing agent that changes to a different color tone.

On the other hand, as the discoloring agent that changes from colorless to colored, there are 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, Examples thereof include primary or secondary arylamine dyes represented by p ′, p ″ -triaminotriphenylmethane.

The proportion of the above-mentioned discoloring agent in the photosensitive composition is preferably 0.01 to 10% by weight, more preferably 0.02 to 5% by weight. These compounds may be used alone or in combination of two or more. Particularly preferred dyes are Victoria Pure Blue BOH and Oil Blue # 603.

(Oil Sensitizer) An oil sensitizer for improving the oil sensitivity of the image area (for example, a half-esterified product of an alcohol of a styrene-maleic anhydride copolymer described in JP-A-55-527). , Pt-butylphenol-
Novolak resins such as formaldehyde resins, or partial esterification products of these with o-quinonediazide compounds, fluorine-based surfactants, p-hydroxystyrene 5
0% fatty acid ester, etc.) are preferably used. The amount of these additives added varies depending on the object of use and purpose, but is generally 0.01 to 30% by weight based on the total solid content.

(Inclusion Compound) The inclusion compound that can be used in the present invention is not particularly limited as long as it is a compound that can include water or an organic molecule, but it is soluble in the solvent used for preparing the composition. Organic compounds are preferred. Examples of such organic compounds include, for example, “Host Guest Chemistry” (Michio Hiraoka et al., Kodansha 1984).
Years, Tokyo) etc. and "Tetrahedron Report"
(No. 226 (1987) P5725A. Colle
t), "Chemical industry April issue" ((1991) P278 Shinkai et al.), "Chemical industry April issue ((1991) P288 Hiraoka et al.), and the like.

Inclusion compounds which can be preferably used in the present invention include, for example, cyclic D-glucans, cyclophanes, neutral polyligands, cyclic polyanions, cyclic polycations, cyclic peptides and SPHERANDS, CAVITAND
NDS) and their acyclic analogs. Among these, cyclic D-glucans and non-cyclic analogs thereof, cyclophanes, and neutral polyligands are more preferable.

Examples of the cyclic D-glucans and acyclic analogs thereof include compounds in which α-D-glucopyranose is linked by a glycolide bond.

Examples of the compound include sugars such as starch, amylose and amylopectone, which are composed of D-glucopyranose groups, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin and D-glucopyranose group. A cyclodextrin having a degree of 9 or more, and SO ₃ C ₆ H ₄ CH ₂ C and the like.
₆ H ₄ SO ₃ group, NHCH ₂ CH ₂ NH group, NHCH ₂
CH ₂ NHCH ₂ CH ₂ NH group, SC ₆ H ₅ group, N ₃
Group, NH ₂ group, NEt ₂ group, SC (NH ₂ ⁺ ) NH
_Two groups, SH group, SCH ₂ CH ₂ NH ₂ group, imidazole group, ethylenediamine group and the like are introduced the following formula

[0071]

Embedded image

Examples include modified D-glucans represented by: Further, the following general formula [VI] and general formula [VI
And a branched cyclodextrin, a cyclodextrin polymer, etc.

[0073]

[Chemical 4]

In the general formula [VI], R _{1 to} R ₃ are
They may be the same or different and each represents a hydrogen atom, an alkyl group or a substituted alkyl group. In particular, those in which R _{1 to} R ₃ are a hydrogen atom or a hydroxyethyl group or a hydroxypropyl group are preferable, and those in which the content of the substituted alkyl group in one molecule is 15% to 50% are more preferable. n ₂ represents a positive integer of 4 to 10.

[0075]

Embedded image

[0076] In the general formula [VII], R represents a hydrogen ^{_{atom, -R 2 -CO 2 H, -R}} 2 -SO 3 H, -R 2 -N
H ₂ or ^{_{-N- (R 3) 2 (R}} 2 represents a straight-chain or branched-chain alkylene group having 1 to 5 carbon atoms, ^{R 3} is linear or branched alkyl having 1 to 5 carbon atoms Represents a group.

An example of producing cyclodextrin is "J
ounal of the American Che
"Mical Society" Vol. 71, p. 354
1949, "Cheimish Berichte"
Vol. 90, page 2561 1949, vol. 90, second
Pp. 561, 1957, but is not of course limited to these.

The branched cyclodextrin used in the present invention is a known cyclodextrin in which a water-soluble substance such as glucose, maltose, cellobiose, lactose, sucrose, galactose or glucosamine, or a water-soluble substance such as disaccharide is branched or added. And preferably,
Maltosyl cyclodextrin in which maltose is bound to cyclodextrin (the number of bound molecules in maltose may be 1, 2, 3 or the like) or glucosyl cyclodextrin in which glucose is bound to cyclodextrin (number of bound molecules in glucose Is 1 molecule, 2 molecules,
3 molecules or the like may be used).

Specific methods for synthesizing these branched cyclodextrins include, for example, Starch Chemistry, Vol. 33, No. 2, 1
Pp. 19-126 (1986), pp. 127-132 (1)
986), Starch Chemistry, Volume 30, No. 2, 231-23.
9 (1983) and the like, and can be synthesized by referring to these known methods. For example, maltosyl cyclodextrin uses cyclodextrin and maltose as raw materials and uses enzymes such as isoamylase and pullulanase. Then, it can be produced by a method of binding maltose to cyclodextrin. Glucosylcyclodextrin can be produced in the same manner.

Although these clathrate compounds may be added as a simple substance, they improve the solubility of the clathrate compound itself or the clathrate compound incorporating the molecule in a solvent and the compatibility with other additives. For this reason, a polymer in which a substituent having an inclusion ability is suspended as a pendant substituent may be added together with the polymer.

Each of these components was dissolved in the following solvent,
By coating and drying the support surface according to the present invention,
By providing a photosensitive layer, the photosensitive lithographic printing plate of the present invention can be manufactured.

(Solvent) As a solvent which can be used when dissolving the photosensitive composition used in the present invention, methanol,
Ethanol, n-propanol, i-propanol, n
-Aliphatic alcohols such as butanol, n-pentanol and hexanol, allyl alcohol, benzyl alcohol, anisole, phenetole, n-hexane, cyclohexane, heptane, hydrocarbons such as octane, nonane and decane, diacetone alcohol, 3 -Methoxy-1
-Butanol, 4-methoxy-1-butanol, 3-ethoxy-1-butanol, 3-methoxy-3-methyl-
1-butanol, 3-methoxy-3-ethyl-1-1-pentanol-4-ethoxy-1-pentanol, 5-methoxy-1-hexanol, acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone, Methyl pentyl ketone, methyl hexyl ketone, ethyl butyl ketone, dibutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, γ-butyrolactone, 3-hydroxy-2-butanone, 4-hydroxy-2-butanone, 4-hydroxy-2- Pentanone, 5-hydroxy-2-pentanone, 4-hydroxy-3-pentanone, 6-hydroxy-2-hexanone, 3-methyl-3-hydroxy-2-
Pentanone, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, ethylene glycol monoacetate, ethylene glycol diacetate, propylene glycol monoacetate, propylene glycol diacetate, ethylene glycol alkyl ethers and their acetates (MC, EC , Butyl cellosolve,
Phenyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, MC acetate, EC acetate), diethylene glycol monoalkyl ethers and their acetates (diethylene glycol monomethyl ether, monoethyl ether, mono i-propyl ether, monobutyl ether, Diethylene glycol monomethyl ether acetate, etc.), diethylene glycol dialkyl ethers (DMDG, DEDG, D
BDG, MEDG), triethylene glycol alkyl ethers (monomethyl ether, monoethyl ether, dimethyl ether, diethyl ether, methyl ethyl ether, etc.), propylene glycol alkyl ethers and their acetates (monomethyl ether, monoethyl ether, n-propyl ether) , Monobutyl ether, dimethyl ether, diethyl ether, monomethyl ether acetate, monoethyl ether acetate, etc.), dipropylene glycol alkyl ethers (monomethyl ether, monoethyl ether, n-propyl ether, monobutyl ether, dimethyl ether, diethyl ether), ethyl formate , Propyl formate,
Carboxylic esters such as butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, dimethylformamide, dimethylsulfoxide, dioxane, tetrahydrofuran, methyl lactate ,
Examples thereof include ethyl lactate, methyl benzoate, ethyl benzoate, propylene carbonate and the like. These solvents can be used alone or in combination of two or more.

(Coating Layer) In the photosensitive lithographic printing plate according to the present invention, a coating layer made of a water-insoluble organic solvent-soluble polymer compound capable of forming a film can be formed on the photosensitive layer.

On the surface of the photosensitive layer provided as described above, a mat layer is provided in order to shorten the vacuuming time in contact exposure using a vacuum baking frame and prevent baking blur. preferable. Specifically, JP-A-50-1258
No. 05, Japanese Patent Publication No. 57-6582, No. 61-28986.
The method of providing a mat layer as described in each of the publications, the method of heat-bonding a solid powder as described in JP-B-62-62337 and the like can be mentioned.

(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 vacuuming time and, in addition, the fine network during exposure due to poor adhesion. It is to prevent the dots from collapsing. As a coating method of the matte layer, there is disclosed in Japanese Patent Laid-Open No. 55-
No. 12974 includes a method of heat-sealing powdered solid powder and a method of spraying polymer-containing water described in JP-A No. 58-182636 and drying, and any method may be used. It is desirable that the matte layer itself be soluble in an alkaline developer or be removable by this.

(Coating) The coating method used for coating the surface of the support with the photosensitive composition or the coating layer or the mat layer is a conventionally known method, for example, spin coating, wire bar coating, dip coating, air knife. Coating, roll coating,
Blade coating and curtain coating are used.

(Exposure) In using the photosensitive lithographic printing plate thus obtained, a conventionally used method can be applied. For example, a transparent original image having a line image, a halftone image or the like can be applied to the photosensitive surface. A relief image is obtained by exposing the film in close contact with it and then removing the photosensitive layer in the non-image area with a suitable developing solution. Suitable light sources for exposure include mercury lamps, metal halide lamps, xenon lamps,
Chemical lamps, carbon arc lamps, etc. are used.

(Processing) In the present invention, the developing solution and the developing replenishing solution used for processing (developing) the photosensitive lithographic printing plate both contain an alkali metal silicate. The alkali metal of the alkali metal silicate includes lithium, sodium and potassium, and potassium is the most preferable.

At the time of development, it is preferable that the development replenisher is appropriately replenished in accordance with the development processing amount of the photosensitive lithographic printing plate.

The preferred developing solution and developing replenishing solution are [SiO 2
₂ ] / [M] (wherein [SiO ₂ ] represents the molar concentration of SiO ₂ and [M] represents the molar concentration of alkali metal) 0.5-2.0, particularly 0.15-1 .0 and SiO
₂ An aqueous solution of an alkali metal silicate having a concentration of 0.5 to 5.0% by weight based on the total weight. Further, particularly preferably, the [SiO ₂ ] / [M] of the developer is 0.25 to 0.7.
5, the SiO ₂ concentration is 1.0 to 4.0% by weight, the development replenisher [SiO ₂ ] / [M] is 0.15 to 0.5, and the SiO ₂ concentration is 1.0 to 3 It is 0.0% by weight.

The above-mentioned developing solution and developing replenishing solution may contain water-soluble or alkali-soluble organic and inorganic reducing agents.

Examples of the organic reducing agent include phenol compounds such as hydroquinone, metol and methoxyquinone, amine compounds such as phenylenediamine and phenylhydrazine, and examples of the inorganic reducing agent include:
For example, sodium sulfite, potassium sulfite, ammonium sulfite, sodium hydrogen sulfite, sulfite salts such as potassium hydrogen sulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, potassium hydrogen phosphite,
Examples thereof include phosphites such as sodium dihydrogen phosphite and potassium dihydrogen phosphite, hydrazine, sodium thiosulfate, and sodium dithionite.

The water-soluble or alkali-soluble reducing agent can be contained in the developing solution and the developing replenishing solution in an amount of 0.05 to 10% by weight.

Further, the developing solution and the developing replenishing solution may contain an organic acid carboxylic acid.

These organic acid carboxylic acids include aliphatic carboxylic acids having 6 to 20 carbon atoms and aromatic carboxylic acids having a benzene ring or naphthalene ring substituted with a carboxyl group.

The aliphatic carboxylic acid has 6 to 2 carbon atoms.
Alkanoic acid of 0 is preferable, and specific examples thereof include caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mistyric acid, palmitic acid,
Stearic acid and the like can be mentioned, with carbon number 6 being particularly preferred.
~ 12 alkanoic acids. Further, the aliphatic carboxylic acid may be a fatty acid having a double bond in the 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 examples of the aromatic carboxylic acid 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 can be mentioned.

The above aromatic carboxylic acid may be used as sodium or potassium salt or ammonium salt.

The content of the aliphatic carboxylic acid and the aromatic carboxylic acid may be at least 0.1 to 30% by weight.

The developer and development replenisher may contain various anionic, nonionic and cationic surfactants and an organic solvent.

Further, known additives can be added to the developing solution and the developing replenishing solution.

[0102]

EXAMPLES The present invention will be described more specifically with reference to the following examples. (Production of grain) Five kinds of aluminum supports having different surface roughening conditions were produced. The manufacturing conditions and the shape of the obtained grain are shown in Table 1 below.

After graining, all the grains were immersed in a 5% aqueous solution of sulfuric acid at 60 ° C. for 10 seconds and then 40
% Sulfuric acid aqueous solution at 40 ° C. for 60 seconds at a current density of 15 A /
After anodizing treatment with dm ^2, it is dipped in a 1.0% ammonium acetate solution at 85 ° C. for 30 seconds, subsequently dipped in an aqueous solution of 0.1% carboxymethyl cellulose at 90 ° C. for 30 seconds, and at 80 ° C. for 5 minutes. A support was prepared by drying.

[0104]

[Table 1] (Note) In this case, the primary pit refers to unevenness obtained by electrochemically treating in an aqueous solution containing nitric acid as a main component.

The secondary pits are irregularities obtained by electrochemically treating in an aqueous solution containing hydrochloric acid as a main component.

[0106]

[Table 2]

A positive type photosensitive composition coating solution having the following composition was applied to the obtained support using a wire bar, and the temperature was adjusted to 80 ° C.
And dried for 2 minutes to obtain a photosensitive lithographic printing plate. At this time, the coating amount of the photosensitive composition coating liquid was 2.0 g as a dry weight.
/ M ² .

<Positive Photosensitive Composition Coating Liquid> Novolac resin (phenol / m-cresol / p-cresol molar ratio is 10/54/36 and Mw is 4000) 6.70 g Pyrogallolacetone resin (Mw: 3000) With o-naphthoquinonediazide-5-sulfonyl chloride (esterification rate 30%) 1.50 g polyethylene glycol # 2000 0.20 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4 -Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.15 g Fluorosurfactant FC-430 (Sumitomo 3M Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.02g Methyl cellosolve 100ml

A positive original film having halftone dots and fine lines was brought into close contact with the obtained photosensitive lithographic printing plate, and 2 kw was used as a light source.
60 at 8 mW / cm ² using a metal halide lamp
It was exposed by irradiation for 2 seconds. This exposed photosensitive lithographic printing plate was processed with a commercially available developer (SDR-I,
Konica Corporation, 6-fold dilution, development time 20 seconds, development temperature 27 ° C.). Printing was performed using the obtained lithographic printing plate, and water width, blanket stain, dot gain, and printing durability were evaluated by the following evaluation methods. The obtained results are shown in Table 2.

<Evaluation of Printing Durability> The lithographic printing plate thus obtained was set in a Heidelberg GTO printing machine, and coated paper printing ink (High Plus Red manufactured by Toyo Ink Mfg. Co., Ltd.) and fountain solution (SEU manufactured by Konica) -3: 2.5%), and printing is continued until defective solidification of the image part of the printed matter appears, or ink is non-imaged on the non-image part. The printing durability was evaluated.

<Evaluation of Dot Gain> The lithographic printing plate thus obtained was set on a DAIYA1F-1 printing machine manufactured by Mitsubishi Heavy Industries, Ltd., and coated paper, dampening water (Tokyo Ink Co., Ltd. etchant SG-51, 1) was used. 0.5%), an ink (High Plus Red manufactured by Toyo Ink Mfg. Co., Ltd.) was used to print with a screen line number of 150 line / inch on the printed matter when the density of the image area was set to 1.6. The area of 50% halftone dots was measured to evaluate the amount of gain. The area was measured with a Macbeth densitometer.

<Evaluation of Blanket Stain> After 10,000 sheets were printed under the same printing conditions as above, the stain on the non-image portion of the blanket was visually evaluated. ⊚: Almost no dirt ○: Slightly dirt but no problem level ×: Dirt

<Evaluation of Water Width> With the ink amount dial kept constant, the water amount dial is changed to set the water amount dial value at which the non-image area starts to become dirty and the water amount dial value at which the ink density of the image area decreases. The difference was defined as the water width. A: Difference is 18 or more in dial value O: Difference is 14 or more and less than 18 in dial value B: Difference is less than 14 in dial value

Example 4 The same experiment as in Example 1 was carried out except that the following negative type photosensitive composition coating liquid was used in place of the positive type photosensitive composition coating liquid in Example 1, and the same effect as in Example 1 was obtained. was gotten.

<Negative-type photosensitive composition coating liquid> Copolymer (p-hydroxyphenylmethacrylamide / acrylonitrile / ethyl acrylate / methacrylic acid = 10/25/57/8 Mw = 60,000) 5.0 g diazo resin (Shown below) 0.5g

[0116]

[Chemical 6] Julimer AC-10L (manufactured by Nippon Pure Chemical Industries, Ltd.) 0.05 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.1 g Methyl Cellosolve 100.0 ml

[0117]

INDUSTRIAL APPLICABILITY According to the present invention, a support for a lithographic printing plate having a wide water width which is a permissible amount of usable water, has printing durability, can suppress blanket stains, and has a good dot gain, and A method for producing the same and a photosensitive lithographic printing plate can be provided.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C25D 11/16 301 C25D 11/16 301 C25F 3/04 C25F 3/04 B G03F 7/00 503 G03F 7/00 503 (72) Inventor Shinichi Matsubara 1 Sakura-cho, Hino-shi, Tokyo Konica Stock Company

Claims (3)

[Claims] 1. An average unevenness of 0.5 to 5 μm, and 50 to 30.
A support for a lithographic printing plate, which is formed by overlapping with 0 nm average unevenness. 2. An aluminum plate surface is sequentially subjected to a) electrochemical surface roughening treatment with an aqueous solution containing nitric acid as a main component, and b) chemical etching treatment with an acid or alkali aqueous solution or electrochemistry in a neutral salt aqueous solution. Etching treatment, and c) electrochemical roughening treatment in an aqueous solution containing hydrochloric acid as a main component, the method for producing a lithographic printing plate support. 3. Average irregularities of 0.5 to 5 μm and 50 to 30
A photosensitive lithographic printing plate comprising a support for a lithographic printing plate, which is formed so as to overlap with 0 nm average unevenness, and a photosensitive layer containing a photosensitive composition is coated on the support.