JP2003307846A - Positive photosensitive composition and positive photosensitive planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive photosensitive composition capable of obtaining a coating film having high sensitivity, excellent visible image quality at the time of exposure, and excellent solvent resistance and abrasion resistance, and a sensitivity. , High visible image quality at the time of exposure, and solvent resistance, especially UV
Provided is a positive photosensitive lithographic printing plate having excellent resistance to UV ink washing oil used during ink printing and excellent printing durability. SOLUTION: A positive photosensitive composition containing an acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group as an alkali-soluble resin and a 1,2-naphthoquinonediazide-6-sulfonic acid ester compound as a photosensitive agent. A positive photosensitive lithographic printing plate comprising a support and a photosensitive layer comprising the positive photosensitive composition of the present invention provided on the surface of the support.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a positive photosensitive composition and a positive photosensitive lithographic printing plate.

[0002]

2. Description of the Related Art Conventionally, a lithographic printing plate used in the field of offset printing has a photosensitive lithographic printing plate provided with a photosensitive layer on a substrate, and after a silver salt mask film having an image formed thereon is brought into close contact with it, The entire surface is exposed to actinic rays to transfer the image onto the photosensitive lithographic printing plate, and then the wet development, the post-treatment and the drying are performed to produce the image. Examples of the actinic ray used at this time include a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, and a carbon arc lamp. The photosensitive layer of the photosensitive lithographic printing plate is designed to be sensitive to light of 300 to 450 nm corresponding to the output wavelength of these light sources.

As such a photosensitive lithographic printing plate, there can be mentioned a positive type photosensitive lithographic printing plate which can be developed with a developing solution (hereinafter referred to as an alkaline developing solution) containing an alkaline aqueous solution. As a positive type photosensitive composition used for the photosensitive layer of such a positive type photosensitive lithographic printing plate, a photosensitive composition containing an alkali-soluble resin and a quinonediazide compound is known.

[0004]

As a specific example of such a combination of an alkali-soluble resin and a quinonediazide compound, a combination of a novolak resin and a 1,2-naphthoquinonediazide-5-sulfonic acid ester compound is the most well known. There is. However, both the novolak resin and the 1,2-naphthoquinonediazide-5-sulfonic acid ester compound have insufficient solvent resistance, and the photosensitive layer containing them is various printing chemicals (washing oil, fountain solution, gum solution, There is a problem that the solvent resistance to the solvent contained in the plate surface protection liquid and the plate cleaner) is insufficient. In particular, there is a problem that the resistance to the UV ink washing oil used at the time of UV ink printing is insufficient and the image area is corroded by the organic solvent. Further, as a result, there is a problem that the printing durability becomes insufficient.

Further, although the solvent resistance of the photosensitive layer is slightly improved by increasing the content of the 1,2-naphthoquinonediazide-5-sulfonic acid ester compound, which is a photosensitizer, with the increase of the photosensitizer. There was a problem that the sensitivity was lowered. When an acrylic copolymer is used instead of the novolac resin, the color difference between the exposed portion and the unexposed portion of the photosensitive layer decreases, making it difficult to visually recognize the exposed image (decrease in visible image property during exposure). There was a problem.

As a sensitizer, 1,2-naphthoquinonediazide-6, which has relatively good solvent resistance, is used instead of 1,2-naphthoquinonediazide-5-sulfonate compound.
-The use of sulfonate compounds has also been investigated. However, 1,2-naphthoquinonediazide-
The absorption wavelength of the 6-sulfonate compound overlaps the wavelength of the fluorescent lamp, and the photosensitive layer is exposed to the light of the fluorescent lamp (fog).
Had a problem. Therefore, so far 1,2
The naphthoquinonediazide-6-sulfonic acid ester compound has rarely been used as a photosensitizer for positive-working photosensitive lithographic printing plates.

As one of the few examples of using a 1,2-naphthoquinonediazide-6-sulfonic acid ester compound as a photosensitizer for a positive-working photosensitive lithographic printing plate, 1,2-naphthoquinonediazide-5-sulfonyl is used as a hydroxyl compound. Halide and 1,2-naphthoquinonediazide-6-
A positive photosensitive lithographic printing plate having a photosensitive layer containing a novolak resin and an ester compound obtained by condensing both sulfonyl halides is disclosed in JP-A-62-279325. However, this positive photosensitive lithographic printing plate also contains novolac resin in the photosensitive layer, and the solvent resistance of the photosensitizer was not sufficiently improved, so that the solvent resistance was not satisfactory. .

Therefore, an object of the present invention is to provide a positive photosensitive composition capable of obtaining a coating film having high sensitivity, excellent visible image property during exposure, and excellent solvent resistance and abrasion resistance. Positive photosensitive lithographic printing with high sensitivity, excellent visible image property during exposure, solvent resistance, especially resistance to UV ink washing oil used in UV ink printing, and excellent printing durability. To provide a version.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that an acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group as an alkali-soluble resin. By combining it with a 1,2-naphthoquinonediazide-6-sulfonic acid ester compound, the sensitivity, the visible image property at the time of exposure, the solvent resistance and the printing durability are improved while suppressing the occurrence of fog. They have found what they can do and have completed the present invention.

That is, the positive photosensitive composition of the present invention contains an acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group and a 1,2-naphthoquinonediazide-6-sulfonic acid ester compound. Is characterized by.

Further, 1,2-naphthoquinonediazide-6
The sulfonic acid ester compound desirably has a urea bond. Further, the acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group preferably has a urea bond.

The positive-working photosensitive lithographic printing plate of the present invention is characterized in that a photosensitive layer comprising the positive-working photosensitive composition of the present invention is provided on the surface of a support.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. <Acrylic Copolymer Having Phenolic Hydroxyl Group and / or Sulfonamide Group> The acrylic copolymer in the present invention includes any of an acrylic acid ester unit, a methacrylic acid ester unit, an acrylamide unit or a methacrylamide unit. A copolymer (hereinafter, acrylic acid ester and methacrylic acid ester are collectively referred to as (meth) acrylic acid ester, and acrylamide and methacrylamide are collectively referred to as (meth) acrylamide). The term "alkali-soluble" as used in the invention means a property of being soluble or swellable in an alkaline aqueous solution, particularly an alkaline developer.

The acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group in the present invention is a copolymer containing a (meth) acrylic acid ester unit and / or a (meth) acrylamide unit and is alkali-soluble. Phenolic hydroxyl group and /
Alternatively, it is not particularly limited as long as it has a sulfonamide group (—SO ₂ —NH ₂ ). Examples of the acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group in the present invention include (meth) acrylic acid ester compounds or (meth) acrylamide compounds having a phenolic hydroxyl group or a sulfonamide group, and Examples thereof include copolymers obtained by copolymerizing with other copolymerizable monomers.

Examples of the (meth) acrylic acid ester compound or the (meth) acrylamide compound having a phenolic hydroxyl group include those represented by the following formulas (1) and (2), which have a sulfonamide group ( Examples of the (meth) acrylic acid ester compound or the (meth) acrylamide compound include those represented by the following formula (3) (wherein A represents an -O- bond or an -NH- bond, and R represents hydrogen. Represents an atom or a methyl group).

[0016]

[Chemical 1]

Further, the acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group in the present invention has a further urea bond (-NH-CO-NH-) because it is more excellent in solvent resistance. Preferably. As such an acrylic copolymer, for example, a (meth) acrylic acid ester compound represented by the following formula (4) and / or formula (5) is copolymerized with another monomer copolymerizable therewith. And a copolymer obtained by the reaction (wherein R represents a hydrogen atom or a methyl group, and X represents 2
Represents a valent linking group, and Y represents a divalent aromatic group which may have a substituent).

[0018]

[Chemical 2]

Specific examples of the (meth) acrylic acid ester compound represented by the formula (4) include 1- (N '-(4-hydroxyphenyl) ureido) methyl acrylate and 1-
(N '-(3-hydroxyphenyl) ureido) methyl acrylate, 1- (N'-(2-hydroxyphenyl) ureido) methyl acrylate, 1- (N '-(3
-Hydroxy-4-methylphenyl) ureido) methyl acrylate, 1- (N '-(2-hydroxy-5-methylphenyl) ureido) methyl acrylate, 1-
(N '-(5-hydroxynaphthyl) ureido) methyl acrylate, 1- (N'-(2-hydroxy-5-phenylphenyl) ureido) methyl acrylate, 2-
(N '-(4-hydroxyphenyl) ureido) ethyl acrylate, 2- (N'-(3-hydroxyphenyl) ureido) ethyl acrylate, 2- (N '-(2
-Hydroxyphenyl) ureido) ethyl acrylate, 2- (N '-(3-hydroxy-4-methylphenyl) ureido) ethyl acrylate, 2- (N'-(2
-Hydroxy-5-methylphenyl) ureido) ethyl acrylate, 2- (N '-(5-hydroxynaphthyl) ureido) ethyl acrylate, 2- (N'-(2
-Hydroxy-5-phenylphenyl) ureido) ethyl acrylate, 4- (N '-(4-hydroxyphenyl) ureido) butyl acrylate, 4- (N'-(3
-Hydroxyphenyl) ureido) butyl acrylate, 4- (N '-(2-hydroxyphenyl) ureido) butyl acrylate, 4- (N'-(3-hydroxy-4-methylphenyl) ureido) butyl acrylate, 4- ( N '-(2-hydroxy-5-methylphenyl) ureido) butyl acrylate, 4- (N'-(5
An acrylate derivative such as -hydroxynaphthyl) ureido) butyl acrylate, 4- (N '-(2-hydroxy-5-phenylphenyl) ureido) butyl acrylate;

1- (N '-(4-hydroxyphenyl)
Ureido) methyl methacrylate, 1- (N '-(3-
Hydroxyphenyl) ureido) methyl methacrylate, 1- (N '-(2-hydroxyphenyl) ureido) methyl methacrylate, 1- (N'-(3-hydroxy-4-methylphenyl) ureido) methyl methacrylate, 1- (N '-(2-hydroxy-5-methylphenyl) ureido) methyl methacrylate, 1- (N'
-(5-hydroxynaphthyl) ureido) methyl methacrylate, 1- (N '-(2-hydroxy-5-phenylphenyl) ureido) methyl methacrylate, 2-
(N '-(4-hydroxyphenyl) ureido) ethyl methacrylate, 2- (N'-(3-hydroxyphenyl) ureido) ethyl methacrylate, 2- (N'-
(2-Hydroxyphenyl) ureido) ethyl methacrylate, 2- (N '-(3-hydroxy-4-methylphenyl) ureido) ethyl methacrylate, 2- (N'
-(2-hydroxy-5-methylphenyl) ureido)
Ethyl methacrylate, 2- (N '-(5-hydroxynaphthyl) ureido) ethyl methacrylate, 2-
(N '-(2-hydroxy-5-phenylphenyl) ureido) ethyl methacrylate, 4- (N'-(4-hydroxyphenyl) ureido) butyl methacrylate,
4- (N '-(3-hydroxyphenyl) ureido) butyl methacrylate, 4- (N'-(2-hydroxyphenyl) ureido) butyl methacrylate, 4- (N '
-(3-hydroxy-4-methylphenyl) ureido)
Butyl methacrylate, 4- (N '-(2-hydroxy-5-methylphenyl) ureido) butyl methacrylate, 4- (N'-(5-hydroxynaphthyl) ureido) butyl methacrylate, 4- (N '-(2- Examples thereof include methacrylate derivatives such as hydroxy-5-phenylphenyl) ureido) butyl methacrylate.
By the way, 2- (N ′-(4-hydroxyphenyl) ureido) ethyl methacrylate has a melting point of 131 to 133.
C., which can be identified from the absorption of the IR spectrum due to the hydroxyl groups and the urea bond.

Specific examples of the (meth) acrylic acid ester compound represented by the formula (5) include 2- (N '-(4-sulfamoylphenyl) ureido) ethyl acrylate and 2
-(N '-(4-sulfamoylphenyl) ureido)
Examples thereof include ethyl methacrylate and 2- (N ′-(2-hydroxy-5-sulfamoylphenyl) ureido) ethyl methacrylate.

Here, the (meth) acrylic acid ester compounds represented by the formulas (4) and (5) include, for example, an isocyanate compound represented by the following formula (6) and an amine compound represented by the following formula (7). It can be obtained by reacting (in the formula, R represents a hydrogen atom or a methyl group,
R'represents a hydrogen atom or an alkyl group which may have a substituent, X represents a divalent linking group, and Y represents a divalent aromatic group which may have a substituent. , Z represents a hydroxyl group or a sulfonamide group).

[0023]

[Chemical 3]

Examples of the isocyanate compound represented by the formula (6) include methacryloyloxyethyl isocyanate and acryloyloxyethyl isocyanate, and examples of the amine compound represented by the formula (7) include 4-aminophenol and 3-amino. Phenol, 2-aminophenol, 4-aminosalicylic acid, 2-aminophenol-4-sulfonamide, 4-aminobenzenesulfonamide, 4-amino-6-chloro-1,3-benzenedisulfonamide and the like can be mentioned.

Specific examples of the other monomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, ethylhexyl acrylate, octyl acrylate, acrylic acid-
t-octyl, chloroethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate,
Acrylic esters such as methoxybenzyl acrylate and tetrahydroacrylate; aryl acrylates such as phenyl acrylate and furfuryl acrylate; methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-
Methacrylic acid esters such as 3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, furfuryl methacrylate and tetrahydrofurfuryl methacrylate; aryl methacrylates such as phenyl methacrylate, cresyl methacrylate and naphthyl methacrylate;

As acrylamide or its derivative, N-methyl acrylamide, N-ethyl acrylamide, N-propyl acrylamide, N-butyl acrylamide, Nt-butyl acrylamide, N-heptyl acrylamide, N-octyl acrylamide, N-cyclohexyl acrylamide. N-alkyl acrylamides such as N-benzyl acrylamide; N-phenyl acrylamide, N-tolyl acrylamide, N-nitrophenyl acrylamide, N-naphthyl acrylamide, N-hydroxy phenyl acrylamide and the like.
-Aryl acrylamides; N, N-dimethyl acrylamide, N, N-diethyl acrylamide, N, N-
Dibutyl acrylamide, N, N-dibutyl acrylamide, N, N-diisobutyl acrylamide, N, N-
N, N-dialkyl acrylamides such as diethylhexyl acrylamide, N, N-dicyclohexyl acrylamide; N-methyl-N-phenyl acrylamide, N-hydroxyethyl-N-methyl acrylamide, N-2-acetamidoethyl-N-acetyl acrylamide Methacrylamides or derivatives thereof are N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-butylmethacrylamide, Nt-butylmethacrylamide, N. -N-alkylmethacrylamides such as -ethylhexylmethacrylamide, N-hydroxyethylmethacrylamide, N-cyclohexylmethacrylamide; N-phenylmethacrylamide, N-naphthyl Such as methacrylamide N-
Aryl methacrylamides; N, N-diethyl methacrylamide, N, N-dipropyl methacrylamide,
N, N-dialkylmethacrylamides such as N, N-dibutylmethacrylamide; N, N-diarylmethacrylamides such as N, N-diphenylmethacrylamide; N-hydroxyethyl-N-methylmethacrylamide, N-methyl -N-phenylmethacrylamide, N-
Methacrylamide derivatives such as ethyl-N-phenylmethacrylamide;

Allyl compounds such as allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, allyloxyethanol; hexyl vinyl ether, octyl. Vinyl ether, dodecyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether,
1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, vinyl phenyl ether Vinyl ethers such as vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthranyl ether: vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl barrate, Vinyl caproate, vinyl chloroacetate, Methoxy acetate, vinyl butoxy acetate, vinyl phenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl -β-
Vinyl esters such as phenyl butyrate, vinyl cyclohexyl carboxylate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate;

Styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, dodecylstyrene, benzylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene. ,
Acetoxymethylstyrene, methoxystyrene, 4-methoxy-3-methylstyrene, dimethoxystyrene, chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, 2- Styrenes such as bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene; crotonic acid esters such as butyl crotonic acid, hexyl crotonic acid, crotonic acid, glycerin monocrotonate; dimethyl itaconate, Dialkyl itaconates such as diethyl itaconate and dibutyl itaconate; Dialkyls of maleic acid or fumaric acid such as dimethyl maleate and dibutyl fumarate;
Maleimide, N-phenylmaleimide, N-2-methylphenylmaleimide, N-2,6-diethylphenylmaleimide, N-2-chlorophenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, N
Maleimides such as hydroxyphenyl maleimide;
In addition, N-vinylpyrrolidone, N-vinylpyridine,
Examples thereof include acrylonitrile and methacrylonitrile. Of these other monomers, the one that is preferably used is
For example, (meth) acrylic acid esters, (meth) acrylamides, maleimides, and (meth) acrylonitriles.

The acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group in the present invention comprises a (meth) acrylic acid ester compound or a (meth) acrylamide compound unit represented by the formulas (1) to (5). It is preferable to contain 10 to 80% by weight. Formula (1)
~ If the (meth) acrylic acid ester compound unit represented by the formula (5) is less than 10% by weight, solvent resistance and alkali solubility may be insufficient, and if it exceeds 80% by weight, the solvent used during coating may be insufficient. There is a risk that it will not dissolve and that the image lines will be eroded during development.

The acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group according to the present invention has a weight average molecular weight of 2,000 or more,
The number average molecular weight is preferably 1,000 or more.
More preferably, the weight average molecular weight is 3,000 to 50.
The number average molecular weight is 2,000-
It is in the range of 400,000.

The blending amount of the acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group in the present invention is based on the total solid content of the positive photosensitive composition.
A range of 5 to 95% by weight is preferable, and a range of 15 to 85% by weight is particularly preferable. Acrylic copolymer content is 5
If it is less than wt%, the developability of the coating film composed of the photosensitive composition,
There is a possibility that the solvent resistance and the abrasion resistance may be insufficient, and if the blending amount exceeds 95% by weight, the developer resistance of the coating film tends to decrease.

<1,2-naphthoquinonediazide-6-sulfonic acid ester compound> The 1,2-naphthoquinonediazide-6-sulfonic acid ester compound is an ester of 1,2-naphthoquinonediazide-6-sulfonic acid and a hydroxyl compound. Is. Preferred are esters of 1,2-naphthoquinone-2-diazide-6-sulfonic acid and phenols.

Examples of such a 1,2-naphthoquinonediazide-6-sulfonic acid ester compound include:
Esters of 1,2-naphthoquinone-2-diazide-6-sulfonyl chloride and polyhydroxybenzophenones; Esters of 1,2-naphthoquinone-2-diazide-6-sulfonyl chloride and phenol-formaldehyde resin or cresol-formaldehyde resin ;
1,2-naphthoquinone-2-diazide-6-sulfonyl chloride ester with pyrogallol-acetone resin; 1,2-naphthoquinone-2-diazide-6-sulfonyl chloride ester with resorcin-benzaldehyde resin; 1,2- Naphthoquinone-2-diazide-6
-Sulfonyl chloride and resorcin-pyrogallol
Ester with acetone co-condensation resin; 1,2-naphthoquinone-2-on polyester having hydroxyl group at the end
Esterified diazido-6-sulfonyl chloride; 1,2-naphthoquinone-2-diazide-in homopolymer of N- (4-hydroxyphenyl) methacrylamide or copolymer with other copolymerizable monomer 6
-Esterified sulfonyl chloride; 1,
An ester of 2-naphthoquinone-2-diazide-6-sulfonyl chloride and a bisphenol-formaldehyde resin; 1,2-naphthoquinone-2- in a copolymer of p-hydroxystyrene homopolymer or other copolymerizable monomer. Examples thereof include those obtained by esterifying diazido-6-sulfonyl chloride.

Among them, as shown in the following formula (8),
An ester of 3,4-trihydroxybenzophenone and 1,2-naphthoquinone-2-diazide-6-sulfonyl chloride, a cresol, represented by the following formula (9):
An ester of formaldehyde resin and 1,2-naphthoquinone-2-diazide-6-sulfonyl chloride is preferably used in a positive photosensitive composition for forming a photosensitive layer of a positive photosensitive lithographic printing plate (formula). In the above, D represents a hydrogen atom or a 1,2-naphthoquinone-2-diazide-6-sulfonyl group, and n represents the number of repeating units).

[0035]

[Chemical 4]

The 1,2-naphthoquinonediazide-6-sulfonic acid ester compound in the present invention preferably has a urea bond, because it is more excellent in solvent resistance. Such a 1,2-naphthoquinonediazide-6-sulfonic acid ester compound is obtained by, for example, reacting an isocyanate compound with an aminophenol to form a urea bond composed of an isocyanate group and an amino group, and then converting the aminophenol to an aminophenol. It can be obtained by reacting the derived phenolic hydroxyl group with 1,2-naphthoquinone-2-diazide-6-sulfonyl halide.

Here, as the isocyanate compound,
Those having a plurality of isocyanate groups in one molecule are preferable. Specifically, diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and xylylene diisocyanate; triisocyanates such as triphenylmethane triisocyanate, lysine triisocyanate and hexamethylene triisocyanate; Vernock DN- 955, Burnock D
N-921S, Burnock DN-950, Burnock Y
6-571, Barnock Y6-572S (all manufactured by Dainippon Ink and Chemicals, Inc.), Takenate D110N,
Takenate D120N, Takenate D160N (above,
Takeda Pharmaceutical Co., Ltd.), Sumidule HT, Sumidule L, Sumidule L1357, Sumidule L1
Adduct type polyisocyanates such as 365 (above, manufactured by Sumitomo Bayer Urethane Co., Ltd.); Barnock DN-
980S, Burnock DN-992S, Burnock DN
-990S, Burnock DN-991S (above, manufactured by Dainippon Ink and Chemicals, Inc.), Takenate D170N and the like (above, manufactured by Takeda Pharmaceutical Co., Ltd.), isocyanurate polyisocyanates; Sumidule N-75,
Sumidur N3200, Sumidur N3200-M
Examples include biuret type polyisocyanates such as X and Sumidur N3200-90E (all manufactured by Sumitomo Bayer Urethane Co., Ltd.). When synthesizing a photosensitizer from these compounds, the higher the content of the isocyanate group, the higher the content of the 1,2-naphthoquinonediazide-6-sulfonyl group of the photosensitizer, the above triisocyanates are It can be used particularly preferably in the invention.

As a specific example of the 1,2-naphthoquinonediazide-6-sulfonic acid ester compound having a urea bond, a polyisocyanate compound represented by the following formula (10) is reacted with 4-aminophenol to give an isocyanate group and an amino group. After forming a urea bond consisting of a group and a phenolic hydroxyl group derived from 4-aminophenol,
-Naphthoquinone-2-diazide-6-sulfonyl chloride is reacted (wherein R '' is
Represents an alkylene group having 2 to 8 carbon atoms).

[0039]

[Chemical 5]

Examples of the polyisocyanate compound represented by the formula (10) include lysine triisocyanate.
The content of the 1,2-naphthoquinonediazide-6-sulfonic acid ester compound is usually 5 to 90% by weight, and more preferably 10 to 10% by weight based on the total solid content of the photosensitive composition.
It is 80% by weight.

<Other Components> The positive photosensitive composition of the present invention may contain a known alkali-soluble resin in addition to the acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group. You can For example,
Phenol-formaldehyde resin, m-cresol-
Formaldehyde resin, p-cresol-formaldehyde resin, m- / p-mixed cresol-formaldehyde resin, phenol / cresol (either m-, p-, or m- / p-mixed) -formaldehyde resin, phenol- Examples thereof include novolak resins such as formaldehyde resins and resorcin-formaldehyde resins, resole resins, polyhydroxystyrene, urethane resins containing acidic groups, and the like. The positive photosensitive composition of the present invention has a feature that the development latitude is further widened by using these known resins in combination, and in combination with a 1,2-naphthoquinonediazide-6-sulfonic acid ester compound, The novolac resin is particularly preferably used. The number average molecular weight of these alkali-soluble resins is preferably 200 to 20,000, and the weight average molecular weight thereof is preferably 300 to 60,000.

In the present invention, it is essential to contain a compound having a 1,2-naphthoquinonediazide-6-sulfonyl group as a photosensitizer, but its isomer, 1,2-naphthoquinonediazide-4. A compound having a -sulfonyl group or a 1,2-naphthoquinonediazide-5-sulfonyl group may be mixed and used. Further, a compound containing two or more kinds of 1,2-naphthoquinonediazidesulfonyl groups having different sulfonyl group substitution positions in one molecule may be used.

In the positive photosensitive composition, if necessary, a cyclic acid anhydride for enhancing sensitivity, a printout agent for obtaining a visible image immediately after exposure, and a dye as an image colorant. , Other fillers can be added. Examples of cyclic acid anhydrides include succinic anhydride, glutaric anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, chloromaleic anhydride, pyromellitic dianhydride, etc. Can be mentioned. These cyclic acid anhydrides can be contained in an amount of 1 to 15% by weight based on the total solid content of the photosensitive composition.

Examples of the printing-out agent for obtaining a visible image immediately after exposure include a combination of a photosensitive compound which releases an acid upon exposure and an organic dye which forms a salt with an acid to change the color tone. it can. Examples of the photosensitive compound which releases an acid upon exposure include 1,2-naphthoquinonediazide-4-sulfonyl halide and trihalomethyl-
2-pyrones, trihalomethyl-s-triazines, various o-naphthoquinonediazide compounds, 2-trihalomethyl-5-aryl-1,3,4-oxadiazole compounds, diazonium salts and the like can be mentioned. These compounds can be used alone or in combination,
The amount added is 0.3 with respect to the total solid content of the photosensitive composition.
The range of 15 wt% is preferred.

Examples of organic dyes capable of forming salts include triphenylmethane dyes, cyanine dyes, diazo dyes and styryl dyes. Specific examples thereof include:
Crystal Violet, Ethyl Violet, Methyl Violet, Methylene Blue, Victoria Blue B
H, Victoria Pure Blue BOH, Malachite Green, Oil Blue # 603, Oil Green BG,
Brilliant green, fuchsin, eosin, rhodamine B, oil pink # 312, oil red 5B, oil black BS, oil yellow # 101, phenolphthalein, cresol red, auramine, leuco crystal violet, leucomalachite green and the like can be mentioned. . The addition amount thereof is preferably in the range of 0.3 to 15% by weight based on the total solid content of the photosensitive composition.

In addition, in the positive photosensitive composition, various resins having a hydrophobic group for improving the ink receptivity of an image, such as octylphenol / formaldehyde resin, t-butylphenol / formaldehyde resin, t- Butylphenol / benzaldehyde resin, rosin-modified novolac resin, and o-naphthoquinonediazide sulfonic acid ester of these modified novolac resins; plasticizers for improving the flexibility of the coating film, for example, dibutyl phthalate, dioctyl phthalate, butyl. Glycolate, tricresyl phosphate, dioctyl adipate, etc.,
Various additives can be added according to various purposes.
The addition amount of these is preferably in the range of 0.01 to 30% by weight based on the total solid content of the photosensitive composition.

<Photosensitive lithographic printing plate> The positive photosensitive lithographic printing plate of the present invention comprises a support and a support provided on the support.
A photosensitive layer made of the above-mentioned positive-type photosensitive composition is used for the general construction.

As the support, for example, aluminum,
Metal plate of zinc, copper, stainless steel, iron, etc .; plastic film of polyethylene terephthalate, polycarbonate, polyvinyl acetal, polyethylene, etc .; paper on which synthetic resin is melt-coated or coated with synthetic resin solution, metal layer is vacuum-deposited and laminated on plastic film And other materials used as a support for the printing plate. Of these, the use of aluminum and a composite support coated with aluminum is particularly preferable.

The surface of the aluminum support is preferably surface-treated for the purpose of enhancing water retention and improving adhesion to the photosensitive layer. As such surface treatment,
For example, a brush polishing method, a ball polishing method, electrolytic etching, chemical etching, liquid honing, surface roughening treatment such as sandblasting, and a combination thereof can be used. Of these, the roughening treatment including the use of electrolytic etching is particularly preferable. As an electrolytic bath used for electrolytic etching, an aqueous solution containing an acid, an alkali or a salt thereof or an aqueous solution containing an organic solvent is used. Among these, an electrolytic solution containing hydrochloric acid, nitric acid, or a salt thereof is particularly preferable.

Further, the surface-roughened aluminum support is optionally desmutted with an acid or alkali aqueous solution. The aluminum support thus obtained is preferably anodized. In particular, anodizing treatment by treatment with a bath containing sulfuric acid or phosphoric acid is desirable.

If necessary, the aluminum support may be treated with silicate (sodium silicate, potassium silicate), potassium fluorozirconate, phosphomolybdate, alkyl titanate, polyacrylic acid, Polyvinyl sulfonic acid treatment, phosphonic acid treatment,
Phytic acid treatment, treatment with a salt of a hydrophilic organic polymer compound and a divalent metal described in JP-A-58-16839 and JP-A-58-18291, JP-A-5-
Hydrophilic treatment by undercoating of a water-soluble polymer having a sulfonic acid group described in JP-A-9-101651, coloring treatment with an acid dye described in JP-A-60-64352, US Pat. No. 3,658,662. Processing such as silicate electrodeposition described in the manual can be performed.

Also preferred is an aluminum support which has been subjected to a sealing treatment after roughening treatment (graining treatment) and anodizing treatment. The sealing treatment is performed by immersing the aluminum support in hot water and a hot aqueous solution containing an inorganic salt or an organic salt,
Alternatively, a steam bath or the like is used.

In the positive photosensitive lithographic printing plate of the present invention, a coating solution prepared by dissolving or dispersing a positive photosensitive composition in an organic solvent is applied on the surface of a support and dried to form a photosensitive layer on the support. Is manufactured by forming. As the organic solvent for dissolving or dispersing the photosensitive composition, any known and commonly used organic solvent can be used. Among them, the boiling point is 40 ° C to 200
C., in particular in the range 60.degree. C. to 160.degree. C., are selected for their advantages in drying.

Examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, n- or iso-propyl alcohol, n- or iso-butyl alcohol and diacetone alcohol; acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl. Ketone, methyl amyl ketone, methyl hexyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone,
Ketones such as methylcyclohexanone and acetylacetone; hexane, cyclohexane, heptane, octane,
Hydrocarbons such as nonane, decane, benzene, toluene, xylene, methoxybenzene; ethyl acetate, n-
Or acetic acid esters such as iso-propyl acetate, n- or iso-butyl acetate, ethyl butyl acetate, hexyl acetate; methylene dichloride,
Halides such as ethylene dichloride and monochlorobenzene; isopropyl ether, n-butyl ether,
Ethers such as dioxane, dimethyldioxane, tetrahydrofuran; ethylene glycol, methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve,
Diethyl cellosolve, cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, methoxymethoxyethanol, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether , Propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol and other polyhydric alcohols and their derivatives; dimethyl sulfoxide, N, N-dimethylformamide, , N- dimethylacetamide, methyl lactate, and the like special solvents such as ethyl lactate.
These may be used alone or as a mixture. And, the concentration of the solid content in the coating liquid is suitably 2 to 50% by weight.

An additive for improving the coating property may be added to the coating liquid. Examples of the additive for improving the coating property include cellulose alkyl ethers, ethylene oxide-based surfactants, fluorine-based surfactants, silicone-based surfactants and the like. Specific examples of the fluorine-based surfactant include anionic fluorine such as perfluoroalkyl group-containing carboxylate salt, perfluoroalkyl group-containing sulfonate salt, perfluoroalkyl group-containing sulfate ester salt, perfluoroalkyl group-containing phosphate salt and the like. -Based surfactants; cationic fluorosurfactants such as perfluoroalkyl group-containing amine salts and perfluoroalkyl group-containing quaternary ammonium salts; perfluoroalkyl group-containing carboxybetaines, perfluoroalkyl group-containing aminocarboxylic acid salts, etc. And amphoteric fluorine-based surfactants; and other perfluoroalkyl group-containing oligomers, perfluoroalkyl group-containing polymers, perfluoroalkyl group-containing sulfonamide polyethylene glycol adducts, and the like.

As the method of applying the coating liquid, for example, roll coating, dip coating, air knife coating, gravure coating, gravure offset coating, hopper coating, blade coating, wire doctor coating, spray coating and the like can be used. The coating amount of coating liquid is 1
A range of 0 ml / m ^{2 to} 100 ml / m ² is suitable.

Drying of the positive-working photosensitive composition coated on the support is usually carried out by heated air. Heating is preferably in the range of 30 ° C to 200 ° C, particularly 40 ° C to 140 ° C. Not only a method of keeping the temperature of drying constant during the drying but also a method of gradually increasing the temperature can be carried out. In some cases, dehumidifying the dry air may give preferable results. The heated air is 0.
It is preferable to supply at a rate of 1 m / sec to 30 m / sec, particularly 0.5 m / sec to 20 m / sec. The coating amount of the positive photosensitive composition is usually about 0.5 to about 5 g / m ^{2 as} a dry weight.
Is the range.

A positive-working photosensitive lithographic printing plate having a photosensitive layer composed of a positive-working photosensitive composition is exposed to the photosensitive layer in a state where a silver salt mask film is in close contact with it, and then developed with a developing solution to give a non-image. By dissolving and removing the part, an image corresponding to the silver salt mask film is formed into a lithographic printing plate on the support. As a suitable light source used for exposure,
Examples include carbon arc lamps, mercury lamps, metal halide lamps, xenon lamps, chemical lamps, lasers, and the like.

As the alkaline agent used in the developing solution,
For example, sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium, potassium or ammonium salt of di- or tri-phosphate, sodium metasilicate, sodium carbonate, inorganic alkali such as ammonia. Compounds: monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, n-butylamine, di-
Examples thereof include organic alkaline compounds such as n-butylamine, monoethanolamine, diethanolamine, triethanolamine, ethyleneimine, and ethylenediamine.

The content of the alkaline agent in the developer is 0.0
The range of 05 to 30% by weight is preferable, and the range of 0.05 to 15% by weight is particularly preferable. When the content of the alkaline agent in the developing solution is less than 0.005% by weight, the development tends to be poor, and when it is more than 30% by weight, it tends to adversely affect the image area during development. It is not preferable because it is in.

An organic solvent may be added to the developing solution. As the organic solvent that can be added to the developer,
For example, ethyl acetate, butyl acetate, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate, butyl levulinate, methyl ethyl ketone, ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone, ethylene glycol monobutyl ether, ethylene glycol monobenzyl ether, Examples thereof include ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbitol, n-amyl alcohol, methyl amyl alcohol, xylene, methylene dichloride, ethylene dichloride and monochlorobenzene. When the organic solvent is added to the developer, the amount of the organic solvent added is preferably 20% by weight or less, and particularly preferably 10% by weight or less.

Further, if necessary, in the above developing solution, water-soluble sulfites such as lithium sulfite, sodium sulfite, potassium sulfite and magnesium sulfite; an alkali-soluble pyrazolone compound, an alkali-soluble thiol compound, and a hydroxy group such as methylresorcin Aromatic compounds; Water softeners such as polyphosphates and aminopolycarboxylic acids;
Sodium isopropyl naphthalene sulfonate, sodium n-butyl naphthalene sulfonate, N-methyl-N
-Various kinds of surfactants such as anionic surfactants such as sodium pentadecylaminoacetate and sodium lauryl sulfate, nonionic surfactants, cationic surfactants, amphoteric surfactants, fluorochemical surfactants and various surfactants and various surfactants. A foaming agent can be used.

As the developing solution, a commercially available developing solution for a positive PS plate can be used in practice. Specifically, a commercially available concentrated PS developer for positive PS plate diluted 1 to 200 times can be used as the developer in the invention.

The temperature of the developing solution is preferably in the range of 15 to 40 ° C., and the immersion time is preferably in the range of 1 second to 5 minutes. If necessary, the surface can be lightly rubbed during development. The developed lithographic printing plate is washed with water and / or treated with a water-based desensitizing agent (finishing gum).
Examples of the water-based desensitizing agent include aqueous solutions of water-soluble natural polymers such as gum arabic, dextrin and carboxymethyl cellulose; water-soluble synthetic polymers such as polyvinyl alcohol, polyvinylpyrrolidone and polyacrylic acid. If necessary, an acid, a surfactant or the like is added to these water-based desensitizing agents. After the treatment with the desensitizing agent, the lithographic printing plate is dried and used as a printing plate for printing.

In such a positive type photosensitive lithographic printing plate, the photosensitive composition forming the photosensitive layer has an acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group as an alkali-soluble resin. Containing a polymer,
1,2-naphthoquinonediazide-6 was used as a photosensitizer.
-Since it is a combination of sulfonic acid ester compounds, improvement in sensitivity, visible image property at the time of exposure, solvent resistance and printing durability can be achieved. In addition to the lithographic printing plate, the photosensitive composition of the present invention can be used in various applications such as photoresist.

[0066]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

<Acrylic Copolymer Having Phenolic Hydroxyl Group and / or Sulfonamide Group> [Acrylic Copolymer A] A flask equipped with a cooling tube, a nitrogen introducing tube, a thermometer, a dropping funnel, and a stirrer was charged with N. , N-
132 parts by weight of dimethylacetamide was poured, and N, N-dimethylacetamide was heated to 80 ° C. with stirring while introducing nitrogen gas into the flask. 2- [N '-(4-
Hydroxyphenyl) ureido] ethyl methacrylate 40 parts by weight, acrylonitrile 45 parts by weight, N-phenylmaleimide 5 parts by weight, methacrylamide 10 parts by weight,
A monomer solution prepared by dissolving 2.4 parts by weight of azobisisobutyronitrile in 132 parts by weight of N, N-dimethylacetamide was added dropwise to the N, N-dimethylacetamide in the flask with stirring over 1 hour. Stirring was continued at 80 ° C. for 3 hours. This solution was poured into water, and the deposited precipitate was collected by filtration and dried under reduced pressure to obtain an acrylic copolymer A having a phenolic hydroxyl group and a urea bond.

[Acrylic Copolymer B] 132 parts by weight of N, N-dimethylacetamide was poured into a flask equipped with a cooling tube, a nitrogen introducing tube, a thermometer, a dropping funnel, and a stirrer, and nitrogen gas was introduced into the flask. While stirring,
The N, N-dimethylacetamide was heated to 80 ° C. Two
-[N '-(4-sulfamoylphenyl) ureido]
40 parts by weight of ethyl methacrylate, acrylonitrile 4
5 parts by weight, N-phenylmaleimide 5 parts by weight, methacrylamide 10 parts by weight, azobisisobutyronitrile 2.
A monomer solution prepared by dissolving 4 parts by weight of 132 parts by weight of N, N-dimethylacetamide was added dropwise to the N, N-dimethylacetamide in the flask over 1 hour with stirring.
Further, stirring was continued at 80 ° C. for 3 hours. This solution was poured into water, and the deposited precipitate was collected by filtration and dried under reduced pressure to obtain an acrylic copolymer B having a sulfonamide group and a urea bond.

<Novolak resin> [Novolak resin C] m-cresol 1 was added in a reactor.
00 parts by weight, p-cresol 66.8 parts by weight, 37% by weight formaldehyde aqueous solution 105 parts by weight and oxalic acid 2.
5 parts by weight of the mixture were heated and stirred at 105 ° C. for 3 hours. Then, the temperature of the reaction product was raised to 175 ° C. to distill off water,
The residual monomer was distilled off from the reaction product under the conditions of 200 ° C. and 100 mmHg. The weight average molecular weight of the novolak resin C thus obtained was 4000.

<1,2-naphthoquinonediazide-6-sulfonic acid ester compound> [Photosensitizer A-6] To 50 g of acetone in the reactor, 2,
3,4-trihydroxybenzophenone 3 g and 1,
10.48 g of 2-naphthoquinonediazide-6-sulfonyl chloride was added while stirring in the reactor. The mixed solution in the reactor was water-cooled, and 4.14 g of triethylamine was appropriately added to the reactor while controlling the reaction temperature at 40 ° C or lower. After completion of the reaction, the reaction mixture was stirred at room temperature for 2 hours. The reaction mixture was poured into 500 g of water, and the formed precipitate was collected by filtration and dried under reduced pressure to obtain 11.4 g of a yellow powder (photosensitive agent A-6).

[Photosensitizer B-6] To 25 g of N, N-dimethylacetamide in the reactor, 4-aminophenol 3.
06 g was added with stirring in the reactor. While cooling the mixed solution in the reactor with water, 2.50 g of lysine triisocyanate (manufactured by Kyowa Hakko Kogyo Co., Ltd.) was slowly put into the reactor, and stirring was continued for 2 hours. Then, 7.54 g of 1,2-naphthoquinonediazide-6-sulfonyl chloride
And 10 g of N, N-dimethylacetamide were added while stirring in the reactor. The mixed solution in the reactor was cooled with water, and 2.98 g of triethylamine was appropriately added to the reactor while controlling the reaction temperature at 40 ° C or lower. After completion of the reaction, the reaction mixture was stirred at room temperature for 2 hours. The reaction mixture is treated with water 5
The resulting precipitate was collected by filtration and dried under reduced pressure to obtain 12.1 g of a yellow powder (photosensitive agent B-6).

[Photosensitizer C-6] Acetone 10 in reactor
0 g of the above novolac resin C 10.0 g and 1,
25.0 g of 2-naphthoquinonediazide-6-sulfonyl chloride was added while stirring the inside of the reactor. The mixed solution in the reactor was cooled with water, and 9.87 g of triethylamine was appropriately added to the reactor while controlling the reaction temperature at 40 ° C or lower. After completion of the reaction, the reaction mixture was stirred at room temperature for 2 hours.
The reaction mixture was poured into 700 g of water, and the formed precipitate was collected by filtration and dried under reduced pressure to obtain 31.0 g of a yellow powder (photosensitive agent C-6).

<1,2-naphthoquinonediazide-5-sulfonic acid ester compound> [Photosensitizer A-5] To 50 g of acetone in the reactor, 2,
3,4-trihydroxybenzophenone 3 g and 1,
10.48 g of 2-naphthoquinonediazide-5-sulfonyl chloride was added while stirring in the reactor. The mixed solution in the reactor was water-cooled, and 4.14 g of triethylamine was appropriately added to the reactor while controlling the reaction temperature at 40 ° C or lower. After completion of the reaction, the reaction mixture was stirred at room temperature for 2 hours. The reaction mixture was poured into 500 g of water, and the formed precipitate was collected by filtration and dried under reduced pressure to obtain 12.0 g of a yellow powder (photosensitive agent A-5).

[Photosensitizer B-5] To 25 g of N, N-dimethylacetamide in the reactor, 4-aminophenol 3.
06 g was added with stirring in the reactor. While cooling the mixed solution in the reactor with water, 2.50 g of lysine triisocyanate (manufactured by Kyowa Hakko Kogyo Co., Ltd.) was slowly put into the reactor, and stirring was continued for 2 hours. Then, 7.54 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride
And 10 g of N, N-dimethylacetamide were added while stirring in the reactor. The mixed solution in the reactor was cooled with water, and 2.98 g of triethylamine was appropriately added to the reactor while controlling the reaction temperature at 40 ° C or lower. After completion of the reaction, the reaction mixture was stirred at room temperature for 2 hours. The reaction mixture is treated with water 5
The resulting precipitate was collected by filtration and dried under reduced pressure to obtain 12.0 g of a yellow powder (photosensitive agent B-5).

[Photosensitizer C-5] Acetone 10 in reactor
0 g of the above novolac resin C 10.0 g and 1,
25.0 g of 2-naphthoquinonediazide-6-sulfonyl chloride was added while stirring the inside of the reactor. The mixed solution in the reactor was cooled with water, and 9.87 g of triethylamine was appropriately added to the reactor while controlling the reaction temperature at 40 ° C or lower. After completion of the reaction, the reaction mixture was stirred at room temperature for 2 hours.
The reaction mixture was poured into 700 g of water, and the formed precipitate was collected by filtration and dried under reduced pressure to obtain 31.0 g of a yellow powder (photosensitive agent C-6).

<Aluminum Support> Thickness 0.24 mm
The aluminum plate of 1 was degreased with an aqueous sodium hydroxide solution, and this was electrolytically polished in a 20% hydrochloric acid bath to obtain a grained plate having a center line average roughness (Ra) of 0.5 μm. Then,
This grained board was subjected to a current density of 2 A / dm ² in a 20% sulfuric acid bath.
Anodizing treatment was performed to form an oxide film of 2.7 g / m ² , then washed with water and dried to obtain an aluminum support.

<Positive-type photosensitive lithographic printing plate> [Example 1] Acrylic copolymer A was used as the acrylic copolymer, and Photosensitizer A-6 was used as the photosensitizer, and the composition A shown in Table 1 was used. Of the coating liquid was prepared, and the coating liquid was coated on an aluminum support with a bar coater.
After drying for a minute, a positive photosensitive lithographic printing plate was obtained. At this time, the dry coating film amount was 1.6 g / m ² .

[0078]

[Table 1]

(Printout) A silver salt mask film was brought into close contact with the obtained photosensitive lithographic printing plate. An exposure amount of 29 unit was used by using an exposure machine P-824-GX (manufactured by Dainippon Screen Mfg. Co., Ltd.) provided with a metal halide lamp with an output of 3 kW at a position 1 m away from the photosensitive lithographic printing plate.
The photosensitive lithographic printing plate was exposed under the conditions of (light amount 50 mJ / cm ² ). The optical density (a) of the unexposed portion and the optical density (b) of the exposed portion were measured using an optical densitometer RD-917 (manufactured by Macbeth) and calculated as ΔOD = (a)-(b). The results are shown in Table 4.

(Sensitivity) A step wedge (manufactured by Ugra Corporation) was brought into close contact with the obtained photosensitive lithographic printing plate. An exposure amount of 29 unit was used by using an exposure machine P-824-GX (manufactured by Dainippon Screen Mfg. Co., Ltd.) provided with a metal halide lamp with an output of 3 kW at a position 1 m away from the photosensitive lithographic printing plate.
The photosensitive lithographic printing plate was exposed under the conditions of (light amount 50 mJ / cm ² ). After that, an automatic developing machine PD-912 (manufactured by Dainippon Screen Co., Ltd.) and a positive plate developing solution PD-1 (manufactured by Kodak Polychrome Graphics Co., Ltd.) were diluted 7 times with water. The exposed photosensitive lithographic printing plate was developed at 30 ° C. for 12 seconds, and the number of clear steps / solid steps of gray scale was read. The results are shown in Table 4.

(Solvent resistance) A test piece was cut out from a photosensitive lithographic printing plate and was placed in a die-cure roller washing oil (manufactured by Dainippon Ink and Chemicals, Inc.) containing 10% by weight of water at room temperature,
Immersion was carried out for 30 minutes and the wash oil resistance was evaluated. The results are shown in Table 4. In the table, ○ means that there was no change in the drawing area,
Δ indicates that the image area was slightly eroded by the wash oil, and x indicates that the erosion was clearly progressed.

(Printing durability) A solid and halftone positive image film and a step wedge were brought into close contact with a photosensitive lithographic printing plate. Output at a position 1 m away from the photosensitive lithographic printing plate 3
Exposure machine P-8 equipped with a kW metal halide lamp
Using 24-GX (manufactured by Dainippon Screen Mfg. Co., Ltd.),
The photosensitive lithographic printing plate was exposed for an exposure time of 4 steps clear. After that, an automatic developing machine PD-912 (manufactured by Dainippon Screen Co., Ltd.) and a positive plate developing solution PD-1 (manufactured by Kodak Polychrome Graphics Co., Ltd.) were diluted 7 times with water. The exposed photosensitive lithographic printing plate is at 30 ° C.
Development for 12 seconds, and finishing gum PF-2 (manufactured by Kodak Polychrome Graphics Co., Ltd.) with water
The liquid diluted twice was applied to the plate surface. Printing was performed using the obtained lithographic printing plate, and the printing durability was judged from the final number of sheets from which an appropriate printed matter was obtained. The results are shown in Table 4. Here, as a printing machine, R-700 (manufactured by Man Roland), U
As V ink, "Dicure Scepter Black" (manufactured by Dainippon Ink and Chemicals, Inc.) and as fountain solution, "NA-1"
08W "(Dainippon Ink and Chemicals, Inc.) 100-fold dilution was used.

[Comparative Example 1] Photosensitizer A-6 was replaced with photosensitizer A-5.
A positive type photosensitive lithographic printing plate was obtained and evaluated in the same manner as in Example 1 except that the above was changed to. The results are shown in Table 4.

Example 2 The procedure of Example 1 was repeated except that the acrylic copolymer A was changed to the acrylic copolymer B and the composition of the coating liquid was changed to the composition B shown in Table 2. A positive photosensitive lithographic printing plate was obtained and evaluated. The results are shown in Table 4.

[0085]

[Table 2]

[Comparative Example 2] Photosensitizer A-6 was replaced with photosensitizer A-5.
A positive type photosensitive lithographic printing plate was obtained and evaluated in the same manner as in Example 2 except that the above was changed to. The results are shown in Table 4.

Example 3 Photosensitizer A-6 was replaced with photosensitizer B-6.
A positive type photosensitive lithographic printing plate was obtained and evaluated in the same manner as in Example 1 except that the above was changed to. The results are shown in Table 4.

[Comparative Example 3] Photosensitizer A-6 was replaced with photosensitizer B-5.
A positive type photosensitive lithographic printing plate was obtained and evaluated in the same manner as in Example 1 except that the above was changed to. The results are shown in Table 4.

Example 4 Photosensitizer A-6 was replaced with photosensitizer C-6.
A positive type photosensitive lithographic printing plate was obtained and evaluated in the same manner as in Example 1 except that the above was changed to. The results are shown in Table 4.

[Comparative Example 4] Photosensitizer A-6 was replaced with photosensitizer C-5.
A positive type photosensitive lithographic printing plate was obtained and evaluated in the same manner as in Example 1 except that the above was changed to. The results are shown in Table 4.

[Comparative Example 5] With Example 1 except that the photosensitizer A-5 was used as the photosensitizer and only the novolac resin C was used as the binder resin, the coating liquid having the composition C shown in Table 4 was used. In the same manner, a positive photosensitive lithographic printing plate was obtained and evaluated. The results are shown in Table 4.

[Comparative Example 6] Comparative Example 6 was the same as Example 1 except that the photosensitizer A-6 was used as the photosensitizer and only the novolac resin C was used as the binder resin. In the same manner, a positive photosensitive lithographic printing plate was obtained and evaluated. The results are shown in Table 4.

[0093]

[Table 3]

[0094]

[Table 4]

From the results shown in Table 4, when 1,2-naphthoquinonediazide-6-sulfonic acid ester compounds were used as photosensitizers (Examples 1 to 4), 1,2-naphthoquinonediazide-5-sulfonic acid esters were used. It can be seen that the printout value is larger than that when the compound is used as a photosensitizer (Comparative Examples 1 to 4), the visible image property during exposure is excellent, and the sensitivity is high. Further, although the number of clear stages in Examples 1 to 4 was larger than that in Comparative Examples 1 to 4, the microline reproducibility was not deteriorated and the fine line reproducibility was excellent. When the 1,2-naphthoquinonediazide-6-sulfonic acid ester compound was used as the photosensitizer (Examples 1 to 4), the 1,2-naphthoquinonediazide-5-sulfonic acid ester compound was used as the photosensitizer. The printing durability was superior to the cases (Comparative Examples 1 to 4).

On the other hand, the combination of the acrylic copolymer and the 1,2-naphthoquinonediazide-5-sulfonate compound is inferior in solvent resistance (Comparative Examples 3 and 4).
was there. Further, in Comparative Examples 5 and 6 in which only the novolac resin was used as the binder resin, the printout was slightly improved, but the solvent resistance and printing durability were remarkably inferior.

[0097]

As described above, the positive photosensitive composition of the present invention comprises the acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group and
Since it contains a 2-naphthoquinonediazide-6-sulfonic acid ester compound, it is possible to obtain a coating film having high sensitivity, excellent visible image property during exposure, and excellent solvent resistance and abrasion resistance. it can.

Also, 1,2-naphthoquinonediazide-6
-If the sulfonic acid ester compound has a urea bond, the solvent resistance of the resulting coating film can be further improved. If the acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group has a urea bond, the solvent resistance of the resulting coating film can be further improved.

The positive-working photosensitive lithographic printing plate of the present invention has a high sensitivity because it has a photosensitive layer comprising the positive-working photosensitive composition of the present invention on the surface of a support. Excellent in visible image quality during exposure, solvent resistance,
Particularly, it has excellent resistance to UV ink washing oil used during UV ink printing, and excellent printing durability.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasuhiro Asawa             Gunma Prefecture Ora-gun, Chiyoda-cho             Duck Polychrome Graphics Stock Association             Inside the Gunma Factory F-term (reference) 2H025 AA01 AA06 AA13 AB03 AC01                       AD03 BE01 CB14 CB15 CB42                       FA17                 2H096 AA06 BA10 EA02

Claims (4)

[Claims] 1. An acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group and 1, 2
-A positive-type photosensitive composition comprising a naphthoquinonediazide-6-sulfonate compound. 2. The positive photosensitive composition according to claim 1, wherein the 1,2-naphthoquinonediazide-6-sulfonic acid ester compound has a urea bond. 3. The positive photosensitive composition according to claim 1, wherein the acrylic copolymer having a phenolic hydroxyl group and / or a sulfonamide group has a urea bond. . 4. A positive-working photosensitive lithographic printing plate comprising a support and a photosensitive layer comprising the positive-working photosensitive composition according to claim 1 provided on the surface of the support.