JPH0798498A - Photosensitive lithographic printing plate - Google Patents

Abstract

PURPOSE:To obtain a photosensitive lithographic printing plate excellent in contrast without deteriorating its sensitivity by successively forming a first org. coating layer consisting of a specified photosensitive composition and a second org. coating layer consisting of surfactant on a substrate. CONSTITUTION:A first org. coating layer consisting of the photo-sensitive composition contg. an o-quinone diazide compd. and an alkali-soluble resin and a second org. coating layer consisting of surfactant are successively provided on a substrate to constitute the plate. The o-quinone diazide compd. is a compd. having an o-quinone diazide group in the molecule, and the ester compd. of the polycondensation resin of the o-naphthoquinone diazide such as o- naphthoquinone diazide sulfonate and phenols or aldehyde and ketone is exemplified. In this case, the substrate is preferably sanded and anodized which are usually conducted in the technical field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate, and more particularly to a photosensitive lithographic printing plate which maintains sensitivity and has excellent contrast.

[0002]

BACKGROUND OF THE INVENTION A photosensitive lithographic printing plate is one in which a photosensitive layer is provided on a hydrophilic support. For example, in a positive type photosensitive lithographic printing plate, an actinic ray such as ultraviolet rays is provided on the hydrophilic support. An ink-receptive photosensitive layer that is solubilized by exposure to is formed.

In such a positive-working photosensitive lithographic printing plate, when the photosensitive layer is imagewise exposed and then developed, the ink-receptive photosensitive layer in the exposed area is removed to expose the surface of the hydrophilic support. On the other hand, the non-exposed portion of the photosensitive layer which is ink-receptive remains on the support to form an ink-receptive layer. In lithographic printing, the difference in the property that the exposed portion is hydrophilic and the unexposed portion is lipophilic is used.

Usually, the photosensitive layer of a positive-working photosensitive lithographic printing plate contains a photosensitive composition containing an o-quinonediazide compound as a photosensitive component and an alkali-soluble resin as a component for enhancing film strength and alkali solubility. Things are used.

As the above-mentioned o-quinonediazide compound,
1,2-naphthoquinone-2-diazide-5-sulfonic acid ester compounds and 1,2-naphthoquinone-2-diazide-4-sulfonic acid ester compounds are generally used as useful compounds, and particularly, pyrogallol and aldehydes. Alternatively, an ester compound with a polycondensation resin with a ketone or the like is preferably used.

When an ester compound with a polycondensation resin or the like is used as the o-quinonediazide compound, a polycondensation resin having a molecular weight of 3000 or more is usually used in order to improve printing durability.

In lithographic printing, the exposed area is hydrophilic and
The photosensitive lithographic printing plate is required to have high contrast photosensitivity because the difference in the property that the unexposed portion is lipophilic is utilized.

Conventionally, in order to make the photosensitive lithographic printing plate have a high contrast, for example, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene higher alcohol. A method of adding a surfactant such as ether to the photosensitive composition has been used. However, if a surfactant is added to the photosensitive composition, the contrast can be increased, but the sensitivity is deteriorated.

Therefore, there has been a demand for a technique for increasing the contrast without degrading the sensitivity.

[0010]

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a photosensitive lithographic printing plate which is excellent in contrast and does not deteriorate sensitivity.

[0011]

The above objects of the present invention are: (1) A first organic coating layer comprising a photosensitive composition containing an o-quinonediazide compound and an alkali-soluble resin on a support, and a second organic coating layer comprising a surfactant. A photosensitive lithographic printing plate comprising an organic coating layer sequentially provided. (2) The photosensitivity according to (1) above, wherein the o-quinonediazide compound is a compound having a 1,2-naphthoquinonediazide-5-sulfonyl group or a 1,2-naphthoquinonediazide-4-sulfonyl group. Planographic printing plate. (3) The photosensitive lithographic printing plate as described in (1) or (2) above, wherein the support is a support that has been subjected to graining treatment and anodic oxidation treatment. Can be achieved by

The present invention will be described in detail below.

First, the support used for forming the photosensitive lithographic printing plate of the present invention will be described.

The support preferably has flexibility so that it can be set in an ordinary printing machine and can withstand a load applied during printing. For example, a metal plate of aluminum, magnesium, zinc, chromium, iron, copper, nickel or the like, Examples thereof include alloy plates of these metals, and metal plates coated with chromium, zinc, copper, nickel, aluminum, iron or the like by plating or vapor deposition can also be used. Of these, the support is preferably one using aluminum or its alloy.

The support is preferably subjected to graining treatment and anodic oxidation treatment which are commonly used in this technical field. The graining treatment and the anodizing treatment are preferably performed in the order of the graining treatment and the anodizing treatment. Usually, the degreasing treatment is performed before the graining treatment and the anodizing treatment.

The degreasing treatment is carried out to remove oil and fat components such as rolling oil adhering to the surface of the support made of aluminum or the like.

As the degreasing treatment, a degreasing treatment using a solvent such as trichlene and thinner, for example, an emulsion degreasing treatment using an emulsion of kerosene and triethanol is used. In addition, an alkaline aqueous solution such as caustic soda can be used for the degreasing treatment. When an aqueous alkali solution such as caustic soda is used for the degreasing treatment, it is possible to remove stains and oxide films that cannot be removed only by the above degreasing treatment.

The support is subjected to a graining treatment in order to improve the adhesion to the photosensitive layer and improve the water retention. The graining treatment mechanically roughens the surface,
There are a so-called mechanical surface-roughening method 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. Further, the electrochemical surface roughening method includes, for example, a method of electrolytically treating with an alternating current or a direct current in an electrolytic solution containing hydrochloric acid, nitric acid or the like. The support can be grained by using any one of these methods or a combination of two or more methods.

Since smut is formed on the surface of the support that has been grained, it is generally preferable to appropriately perform washing with water or alkali etching in order to remove the smut. As such processing, for example,
Treatment methods such as the alkali etching method described in JP-B-48-28123 and the sulfuric acid desmutting method described in JP-A-53-12739 can be mentioned.

The support usually has abrasion resistance, chemical resistance,
Furthermore, in order to improve water retention, it is preferable to form an oxide film by anodic oxidation. Anodizing is generally 10 to 50% of sulfuric acid and / or phosphoric acid, etc.
Current density of 1 to 10 A using an aqueous solution containing a concentration of
A method of electrolyzing at / dm ² is used, but US Pat.
US Pat. No. 3,511,661 and a method for electrolyzing in sulfuric acid at high current density described in US Pat.
It is also possible to use the method of electrolysis using phosphoric acid described in the specification.

The support may be further subjected to surface treatment such as sealing treatment.

Next, the positive photosensitive composition containing the o-quinonediazide compound and the alkali-soluble resin used in the first organic coating layer of the present invention will be described.

The o-quinonediazide compound is a compound having an o-quinonediazide group in the molecule, and is a polycondensation of an o-naphthoquinonediazide compound such as o-naphthoquinonediazide sulfonic acid with a phenol and an aldehyde or ketone. Examples thereof include ester compounds with resins.

Examples of the phenols in the polycondensation resin with the above-mentioned phenols and aldehydes or ketones include phenol, o-cresol, m-cresol,
Examples include monohydric phenols such as p-cresol, 3,5-xylenol, carvacrol, thymol, dihydric phenols such as catechol, resorcin, and hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin. Examples of the aldehyde include formaldehyde,
Examples thereof include benzaldehyde, acetaldehyde, crotonaldehyde and furfural. Of these, preferred are formaldehyde and benzaldehyde. Examples of ketones include acetone and methyl ethyl ketone.

Specific examples of polycondensation resins of phenols and aldehydes or ketones include phenol-formaldehyde resin, m-cresol-formaldehyde resin, m- and p-mixed cresol-formaldehyde resin, resorcin-benzaldehyde resin, pyrogallol. -Acetone resin etc. are mentioned.

The o-naphthoquinonediazide sulfonic acid is preferably 1,2-naphthoquinonediazide-5-sulfonic acid or 1,2-naphthoquinonediazide-4-sulfophonic acid.

In the o-naphthoquinonediazide compound, the condensation rate of o-naphthoquinonediazide sulfonic acid with respect to the OH group of phenols (reaction rate with respect to one OH group) is preferably 15 to 80%, more preferably 2
0 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 mentioned. That is, for example, 1,2-benzoquinone diazide sulfonic acid ester, 1,2-naphthoquinone diazide sulfonic acid ester, 1,2-benzoquinone diazide sulfonic acid amide,
Known 1,2-quinonediazide compounds such as 1,2-naphthoquinonediazide sulfonic acid amide, more specifically, J. Kosar "Light-Sensitive Systems" No. 33.
Pages 9-352 (1965), John Willey & Sons (New York)
And W S De Fores
t) 1,2-Benzoquinonediazide-4-sulfonic acid phenyl ester, 1, described in "Photoresist", Volume 50 (1975), McGraw Hill Company (New York).
2,1 ′, 2′-di- (benzoquinonediazide-4-sulfonyl) -dihydroxybiphenyl, 1,2-benzoquinonediazide-4- (N-ethyl-N-β-naphthyl) -sulfonamide, 1,2- Naphthoquinonediazide-5-sulfonic acid cyclohexyl ester, 1- (1,
2-naphthoquinonediazide-5-sulfonyl) -3,5
-Dimethylpyrazole, 1,2-naphthoquinonediazide-5-sulfonyl-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-sulfonyl-2,
4-dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-sulfonic acid-2,3,4-trihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-sulfonic acid chloride 2 mol and 4,
Condensate with 1 mol of 4'-diaminobenzophenone, 1,
2-naphthoquinonediazide-5-sulfonic acid chloride 2
, A condensate of 1,4'-dihydroxy-1,1'-diphenylsulfonic acid 1 mol, a condensate of 1,2-naphthoquinonediazide-5-sulfonic acid chloride 1 mol and purpurogallin 1 mol, 1,2 -Naphthoquinone diazide-
An example is a 1,2-quinonediazide compound such as 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-quinonediazide ester compound obtained by reacting 1,2-naphthoquinonediazidesulfonyl chloride with pyrogallol-acetone condensation resin or 2,3,4-trihydroxybenzophenone is particularly preferable.

In the present invention, as the o-quinonediazide compound, 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 5 to 60% by weight, particularly preferably 10 to 50% by weight.

The alkali-soluble resin used in the present invention is 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 include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensation resin as described in JP-A-55-57841, JP-A-55. Examples thereof include a copolycondensation resin of p-substituted phenol and phenol or cresol and formaldehyde as described in JP-A-127553.

The molecular weight (polystyrene standard) of the novolac resin is preferably 3.00 × 10 in terms of number average molecular weight Mn.
^{2 to} 7.50 × 10 ³ , weight average molecular weight Mw of 1.00 ×
10 ^{3 to} 3.00 × 10 ⁴ , more preferably Mn of 5,0
0 × 10 ^{2 to} 4.00 × 10 ³ , Mw of 3.00 × 10 ^3.
˜2.00 × 10 ⁴ .

The above novolak resins may be used alone or in combination of two or more kinds.

The proportion of the novolak resin in the photosensitive composition is preferably 5 to 95% by weight.

The above-mentioned vinyl polymer having a phenolic hydroxyl group used in the present invention is a polymer having a unit having a phenolic hydroxyl group in its molecular structure,
A polymer containing at least one structural unit represented by the following general formulas [I] to [V] is preferable.

[0038]

[Chemical 1]

In the general formulas [I] to [V], 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, and preferably a hydrogen atom.
A represents an alkylene group, which connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, and may have a substituent,
m represents an integer of 0 to 10, and B represents a phenylene group which may have a substituent or a naphthylene group which may have a substituent.

The vinyl polymer having a phenolic hydroxyl group used in the present invention preferably has a copolymer type structure, and is a structural unit represented by the above general formula [I] to general formula [V]. As the monomer to be copolymerized with, for example, ethylene, propylene, isobutylene, butadiene, isoprene and other ethylenically unsaturated olefins, for example, styrene, α-methylstyrene,
Styrenes such as p-methylstyrene and p-chlorostyrene, for example, acrylic acids such as acrylic acid and methacrylic acid, for example, unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid and maleic anhydride, for example acrylic acid Methyl, ethyl acrylate, -n-butyl acrylate,
Esters of α-methylene aliphatic monocarboxylic acids such as isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate and ethyl ethacrylate. For example, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide, and anilides such as acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, and m-methoxyacrylanilide, such as acetic acid. Vinyl esters such as vinyl, vinyl propionate, vinyl benzoate and vinyl acetate, for example, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether and β-chloroethyl vinyl ether. , Vinyl chloride, vinylidene chloride, vinylidene cyanide, for example, 1-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, 1-methyl-1 -Ethylene derivatives such as nitroethylene, for example N-vinylpyrrole,
N-vinylcarbazole, N-vinylindole, N-
There are N-vinyl monomers such as vinylpyrrolidene and N-vinylpyrrolidone. These monomers are present in the polymer compound in a structure in which the unsaturated double bond is cleaved.

Of the above-mentioned monomers, aliphatic monocarboxylic acid esters and nitriles are preferable because they exhibit excellent performance for the purpose of the present invention.

These monomers may be bonded to the polymer used in the present invention in either a block or random state.

The proportion of the vinyl polymer having a phenolic hydroxyl group in the photosensitive composition is preferably 0.5 to 70% by weight.

As the vinyl polymer having a phenolic hydroxyl group, the above polymers may be used alone or in combination of two or more kinds. It can also be used in combination with other polymer compounds.

The proportion of the quinonediazide compound in the photosensitive composition is preferably 5 to 60% by weight, particularly preferably 10 to 50% by weight.

The photosensitive composition of the present invention preferably contains a compound which forms an acid or a free radical upon exposure.

As such a compound, a trihaloalkyl compound represented by the following general formula [VI] and a diazonium salt compound represented by the general formula [VII] are preferably used.

[0048]

[Chemical 2] [In the formula, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, W represents each atom of N, S, Se, P, and C, Z represents O, N, S, Se, Represents each atom of P. Y
Represents a non-metal atom group having a chromophore group and necessary for cyclizing W and Z. However, the ring formed by the non-metal atom group may have the above Xa. ]

[0049]

[Chemical 3] [In the formula, Ar represents an aryl group, and X ⁻ represents a counter ion. More specifically, the trihaloalkyl compound of the general formula [VI] includes a compound represented by the following general formula [VIII], general formula [IX] or general formula [X].

[0050]

[Chemical 4] [In the formula, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, L represents a hydrogen atom or a methyl group, J represents a substituted or unsubstituted aryl group or a heterocyclic group, and n is 0, 1 or It is 2. ] Specific examples of the compound represented by the general formula [VIII] include:

[0051]

[Chemical 5]

Oxadiazole compounds having a benzofuran ring such as 2-trichloromethyl-5- (p-methoxystyryl) -1,3,4-oxadiazole described in JP-A-54-74728. Compound,

[0053]

[Chemical 6]

[0054]

[Chemical 7] Etc.

Specific examples of the compound represented by the general formula [IX] or the general formula [X] are disclosed in JP-A-53-3622.
4- (2,4-dimethoxy-
4-styryl) -6-trichloromethyl-2-pyrone,
2,4 described in JP-A-48-36281
Examples thereof include -bis- (trichloromethyl) -6-p-methoxystyryl-s-triazine and 2,4-bis- (trichloromethyl) -6-p-dimethylaminostyryl-s-triazine.

The diazonium salt compound is preferably a diazonium salt which generates a strong Lewis acid upon exposure, and the counterion of an inorganic compound is recommended as the counterion portion. As such a compound, the anion portion of the diazonium salt is phosphorus fluoride ion, arsenic fluoride ion,
An aromatic diazonium salt composed of at least one kind of antimony fluoride ion, antimony chloride ion, tin chloride ion, bismuth chloride ion and zinc chloride ion, preferably a paradiazophenylamine salt, can be mentioned.

The compound which produces an acid or a free radical upon exposure to light is 0.01 to 20% by weight in the total composition of the photosensitive layer.
It is preferably contained, and more preferably 0.1 to 20.
%, And particularly preferably 0.2 to 10% by weight.

In the photosensitive composition of the present invention, together with the above-mentioned compound which forms an acid or a free radical upon exposure,
It is preferable to include a color-changing agent that changes the color tone by interacting with the generated acid or free radical.

Such color-changing agents include those that develop color and those that fade or change color.

Examples of the discoloring agent that discolors or discolors include diphenylmethane, triphenylmethane type thiazine, oxazine type, xanthene type, anthraquinone type,
Various dyes such as iminonaphthoquinone type and azomethine type are effectively used.

Specific examples of these include brilliant green, eosin, ethyl violet, erythrosin B, methyl green, crystal violet,
Basic fuchsin, phenolphthalein, 1,3-
Diphenyltriazine, alizarin red S, thymolphthalein, methyl violet 2B, quinaldine red, rose bengal, methanyl yellow, thymol sulfophthalein, xylenol blue, methyl orange,
Orange IV, diphenylthiocarbazone, 2,7-dichlorofluorescein, paramethyl red, congo red, benzopurpurin 4B, α-naphthyl red, Nile blue 2B, Nile blue A, phenacetaline, methyl violet, malachite green, parafuchsin, Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue # 603 [manufactured by Orient Chemical Industry Co., Ltd.], Oil Pink # 312 [manufactured by Orient Chemical Industry Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd. )], Oil scarlet # 308 [manufactured by Orient Chemical Industry Co., Ltd.], oil red OG [manufactured by Orient Chemical Industry Co., Ltd.], oil red RR [manufactured by Orient Chemical Industry Co., Ltd.], oil green # 502 [Orient Chemical Industry Co., Ltd.], Pironreddo BEH Special [Hodogaya Chemical Co., Ltd.], m- cresol purple, cresol red, rhodamine B, rhodamine 6
G, first acid violet R, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p
-Diethylaminophenyliminonaphthoquinone, 2-carbostearylamino-4-p-dihydrooxyethylamino-phenyliminonaphthoquinone, p-methoxybenzoyl-p'-diethylamino-o'-methylphenyliminoacetanilide, cyano-p-diethylaminophenylimino Acetanilide, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone and the like can be mentioned.

Further, arylamines can be used as the color-changing agent for coloring. Suitable arylamines for this purpose include simple arylamines such as primary and secondary aromatic amines as well as so-called leuco dyes, examples of which include diphenylamine, dibenzylaniline, triphenyl. Amine, diethylaniline, diphenyl-p-phenylenediamine, p-toluidine, 4,4'-biphenyldiamine, o-chloroaniline, o-bromoaniline, 4-chloro-o-phenylenediamine, o-bromo-N, N. -Dimethylaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, aniline, 2,5-
Dichloroaniline, N-methyldiphenylamine, o-
Toluidine, p, p'-tetramethyldiaminodiphenylmethane, N, N-dimethyl-p-phenylenediamine, 1,2-dianilinoethylene, p, p ', p "-hexamethyltriaminotriphenylmethane, p, p ′-
Tetramethyldiaminotriphenylmethane, p, p'-
Tetramethyldiaminodiphenylmethylimine, p,
p ', p "-triamino-o-methyltriphenylmethane, p, p', p" -triaminotriphenylcarbinol, p, p'-tetramethylaminodiphenyl-4-
Examples thereof include anilinonaphthylmethane, p, p ′, p ″ -triaminotriphenylmethane, p, p ′, p ″ -hexapropyltriaminotriphenylmethane and the like.

In the present invention, among the above-mentioned color changing agents, dyes capable of changing color in the pH range of 1 to 5 are preferable.

The above color-changing agent is contained in the entire photosensitive layer composition in an amount of 0.0
The content is preferably 1 to 10% by weight, more preferably 0.02 to 5% by weight.

The photosensitive composition of the present invention preferably further contains various organic acids and acid anhydrides.

As the above-mentioned organic acid, various organic acids can be used and are not particularly limited.
Is preferably an organic acid having a pKa value of 2 or more,
An organic acid having a Ka value of 3.0 to 9.0 is more preferable,
Organic acids having a pKa value of 3.5 to 8.0 are particularly preferable.

Examples of such an organic acid include Chemical Handbook Basic Edition II (Maruzen Co., Ltd., 1966, Nos. 1054 to 1058).
Examples of the organic acid described in page) are compounds that can exhibit the pKa value of the present invention.

Examples of such organic acids include benzoic acid, adipic acid, azelaic acid, isophthalic acid and p-
Toluic acid, o-toluic acid, β-ethylglutaric acid,
m-oxybenzoic acid, p-oxybenzoic acid, 3,5-dimethylbenzoic acid, 3,4-dimethoxybenzoic acid, glyceric acid, glutaconic acid, glutaric acid, p-anisic acid, succinic acid, sebacic acid, β, β-diethylglutaric acid,
1,1-cyclobutanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, β, β-dimethylglutaric acid , Dimethylmalonic acid, α-tartaric acid, suberic acid, terephthalic acid, pimelic acid, phthalic acid, fumaric acid, β-propylglutaric acid, propylmalonic acid, mandelic acid, mesotartaric acid, β-methylglutaric acid, β, β- Methyl propyl glutaric acid, methyl malonic acid, malic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid and the like can be mentioned.

In addition to the above materials, a plasticizer, a surfactant and the like can be added to the photosensitive composition, if necessary.

In the first organic coating layer of the present invention, a coating solution prepared by dissolving a photosensitive composition comprising an o-quinonediazide compound, an alkali-soluble resin and other components used as necessary in a solvent is coated on a support. It can be formed by drying.

Examples of the solvent that can be used to dissolve the photosensitive composition include methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl. Ether, diethylene glycol diethyl ether, diethylene glycol monoisopropyl ether, propylene glycol, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, ethyl formate, propylic acid formate , Butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate,
Examples thereof include ethyl butyrate, dimethylformamide, dimethylsulfoxide, dioxane, acetone, methylethylketone, cyclohexanone, methylcyclohexanone, diacetone alcohol, acetylacetone and γ-butyrolactone. These solvents may be used alone or in admixture of two or more.

The coating method used for coating the photosensitive composition on the surface of the support is a conventionally known method, for example, spin coating, wire bar coating, dip coating, air knife coating, spray coating, air spray coating, Electrostatic air spray coating, roll coating, blade coating, curtain coating and the like can be used.

Next, the second organic coating layer made of a surfactant will be described.

Examples of the surfactant used in the second organic coating layer include amphoteric surfactants, anionic surfactants, cationic surfactants, nonionic surfactants, fluorine-based surfactants and the like.

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 ester salt, naphthalene sulfone Examples include acid formalin condensates and polyoxyethylene alkyl phosphates.

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 fluorine-based surfactant 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.

The second organic coating layer of the present invention can be formed by applying a coating solution prepared by dissolving a surfactant in a solvent onto a support and drying the coating solution.

The solvent used for dissolving the surfactant is methyl cellosolve, methyl cellosolve acetate,
Ethyl cellosolve, cellosolves such as ethyl cellosolve acetate, linear alcohols such as methanol and ethanol, iso-propyl alcohol, branched alcohols such as tert-butyl alcohol, water, dimethylformamide, dimethylsulfoxide, dioxane, acetone, cyclohexanone, Examples thereof include trichloroethylene and methyl ethyl ketone. These solvents may be used alone or in admixture of two or more.

The concentration of the surfactant in the coating solution is 0.01
It can be used in an amount of from 10 to 10%, particularly preferably from 0.5 to 5%.

As the coating method used for coating the surface of the support with the photosensitive composition, the coating methods mentioned above as the coating method of the first organic coating layer can be used.

The preferable coating amount of the second organic coating layer is from 1 to
It was 50 mg / dm ^2, more preferably 3 to 30 mg / dm ^2.

The photosensitive lithographic printing plate of the present invention can be exposed and developed by a conventionally used method.
For example, a transparent original image having a line image, a halftone dot image, etc. is brought into close contact with the photosensitive surface for exposure, and then the photosensitive layer in the non-image area is removed using an appropriate developing solution to obtain a relief image. . Suitable light sources for exposure include mercury lamps, metal halide lamps, xenon lamps, chemical lamps,
Carbon arc lamps and the like, and the developer used for development is preferably an alkaline aqueous solution, for example, sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, sodium triphosphate, diphosphoric acid. An aqueous solution of sodium, sodium carbonate, potassium carbonate, etc. may be mentioned. The concentration of the alkaline aqueous solution at this time varies depending on the type of the photosensitive composition and the alkali, but is generally in the range of 0.1 to 10% by weight. It is also possible to add an organic solvent such as alcohol or the like.

[0086]

【Example】

Example 1 [Preparation of support] A 0.3 mm thick aluminum plate (material 1050, tempered H16) was immersed in a 5% sodium hydroxide aqueous solution kept at 65 ° C, and degreasing treatment was performed for 1 minute. And washed with water. This degreased aluminum plate is placed at 25 ° C
It was immersed in a 10% aqueous solution of sulfuric acid kept for 1 minute for neutralization and then washed with water. Then, this aluminum plate was placed in a 1.0 wt% hydrochloric acid aqueous solution at a temperature of 25 ° C. and a current density of 1
After electrolytically roughening the surface for 60 seconds with an alternating current under the condition of 00 A / dm ² , desmutting treatment was carried out for 10 seconds in a 5% sodium hydroxide aqueous solution kept at 60 ° C. Then, in a 20% sulfuric acid solution, the temperature was 20 ° C. and the current density was 3 A /
Anodizing treatment was performed for 1 minute under the condition of dm ² . Then 8
It was immersed in a 1% sodium nitrite aqueous solution kept at 0 ° C for 30 seconds, washed with water, and dried at 80 ° C for 3 minutes. In addition, 85
After immersing in an aqueous solution of carboxymethylcellulose (concentration: 0.1% by weight) kept at 0 ° C for 30 seconds, it was dried at 80 ° C for 5 minutes to prepare a support.

[Preparation of Photosensitive Lithographic Printing Plate Sample] A coating solution for the following first organic coating layer was applied onto the above support using a wire bar, dried at 80 ° C. for 2 minutes, and further subjected to the following 2 The coating liquid for the organic coating layer was applied using a wire bar and dried at 80 ° C. for 2 minutes to obtain the photosensitive lithographic printing plate samples (Samples 1 to 5 and 8) of the invention.

(Sample 1) <Coating liquid for first organic coating layer> Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallol acetone Condensate of resin and o-naphthoquinonediazide-5-sulfonyl chloride 1.5 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4-bis (trichloromethyl) -6- (p-methoxystyryl) ) -S-Triazine 0.15 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g Methyl cellosolve 100 ml <Coating liquid for second organic coating layer> Lauryl dimethylamino oxide 0.6 g Water / methanol [5/5 ( V / V)] 25 ml

(Sample 2) <Coating liquid for first organic coating layer> (Same as sample 1) <Coating liquid for second organic coating layer> Sodium stearate 0.6 g Water / methanol [5/5 (V / V) )] 25 ml (Sample 3) <Coating liquid for first organic coating layer> (Same as Sample 1) <Coating liquid for second organic coating layer> n-octylamine chloride 0.6 g Water / methanol [5/5 ( V / V)] 25 ml

(Sample 4) <Coating liquid for first organic coating layer> (Same as sample 1) <Coating liquid for second organic coating layer> Polyethylene glycol # 2000 0.6 g Water / methanol [5/5 (V / V)] 25 ml (Sample 5) <Coating liquid for first organic coating layer> (Same as Sample 1) <Coating liquid for second organic coating layer> FC-430 (Sumitomo 3M Ltd.) 0.6 g Water / Methanol [5/5 (V / V)] 25 ml (Sample 8) <Coating liquid for first organic coating layer> (Same as sample 1) <Coating liquid for second organic coating layer> JURIMER SEK101 (Nippon Pure Chemical Co., Ltd.) 0.6 g Water / methanol [5/5 (V / V)] 25 ml

Further, the following coating liquid was applied onto the above support using a wire bar and dried at 80 ° C. for 2 minutes,
Comparative photosensitive lithographic printing plate samples (Samples 6 and 7) were obtained. (Sample 6) <Coating liquid> (Same as the coating liquid of the first organic coating layer of Sample 1) (Sample 7) <Coating liquid> Novolak resin (phenol / m-cresol / p-cresol molar ratio is 10 / 54/36, weight average molecular weight 4000) 6.7 g Condensation product of pyrogallol acetone resin and o-naphthoquinonediazide-5-sulfonyl chloride 1.5 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.08 g 2,4 -Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.15 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g polyethylene glycol # 2000 0.2 g methyl cellosolve 100 ml. For each of the lithographic printing plate samples 1 to 7, the sensitivity and the high contrast were evaluated by the following evaluation methods. The sex was evaluated. The results obtained are shown in Table 1.

[Evaluation Method] <Evaluation of Sensitivity> A step tablet for sensitivity measurement (No. 2 manufactured by Eastman Kodak Co., concentration difference 0.1)
2 steps of 5 steps each with 21 steps of gray scale)
w A metal halide lamp (Iwasaki Denki Idol Fin 2000) is used as a light source, and a distance of 90 cm is 4
It was exposed for 0 seconds. Next, this sample was treated with a developer obtained by diluting SDR-1 (manufactured by Konica Corporation) developer 6 times with water at 27 ° C.
Was developed for 20 seconds, and the number of clear stages that were completely developed was determined from the obtained gray scale developed image. The larger the number of clear steps, the higher the sensitivity.

<Evaluation of Hardness> A sample tablet for sensitivity measurement (Eastman Kodak No. 2,
2Kw metal halide lamp (manufactured by Iwasaki Electric Co., Ltd.) by closely adhering to 21 levels of gray scale with a density difference of 0.15 each
Idol fin 2000) is used as a light source, 90 cm
Was exposed for 40 seconds from the distance. Next, this sample is SDR-
1 (manufactured by Konica Corporation) developer was developed with a developer diluted 6 times with water at 27 ° C. for 20 seconds, and the obtained gray scale developed image was completely developed with the number of solid steps not completely developed. The number of clear steps is calculated, and the contrast is evaluated from the value of [solid step number-clear step number]. The smaller this value, the better the contrast. ◯: [solid stage number-clear stage number] is 7.0 or less Δ; [solid stage number-clear stage number] is 7.0 to 10.0 ×; [solid stage number-clear stage number] is larger than 10.0

[0094]

[Table 1]

[0095]

INDUSTRIAL APPLICABILITY The photosensitive lithographic printing plate of the present invention has no deterioration in sensitivity and is excellent in contrast.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Matsubara 1 Sakura-cho, Hino City, Tokyo Konica Co., Ltd. In-house (72) Inventor Katsuko Ota 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Co., Ltd. In the laboratory

Claims (3)

[Claims] 1. A first organic coating layer made of a photosensitive composition containing an o-quinonediazide compound and an alkali-soluble resin, and a second organic coating layer made of a surfactant are sequentially provided on a support. Characteristic photosensitive lithographic printing plate. 2. The o-quinonediazide compound is 1,2-
Naphthoquinonediazide-5-sulfonyl group or 1,2
A photosensitive lithographic printing plate according to claim 1, which is a compound having a naphthoquinonediazide-4-sulfonyl group. 3. The photosensitive lithographic printing plate according to claim 1, wherein the support is on a support subjected to a graining treatment and an anodic oxidation treatment.