JPH02304568A - Photosensitive composition and photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To obtain the printing plate having good preservable stability, more particularly, good preservable developability by incorporating a diazo resin, alkaline soluble and swellable high-polymer compd. and radical capturing agent as the photosensitive compsn. into the printing plate. CONSTITUTION:The diazo resin, the alkaline soluble and swellable high-polymer compd. and the radical capturing agent are incorporated into the printing plate. The diazo resin is used as a photosensitive material in this case, for which a cocondensated diazo resin contg. an arom. compd. having 1 pieces of at least either of carboxyl groups or hydroxyl groups and an arom. diazonium compd. as constituting units is preferably usable. The alkaline soluble and swellable high-polymer compd. has the alkaline solubility or alkaline swellability or both the properties in combination and is exemplified by, for example, polyamide, polyether, etc. Radical capturing agents which are generally used as, for example, an antioxidant, etc., are usable as the radical capturing agent. The printing plate having the excellent preservable stability and more particularly the preservable developability is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive composition and a photosensitive lithographic printing plate.

[Background of the invention]

BACKGROUND OF THE INVENTION Various photosensitive compositions have heretofore been proposed, and these are used, for example, as photosensitive lithographic printing plates by being coated on a support.

Conventionally, compositions containing diazo resins or photosensitive planographic printing plates having such compositions as photosensitive layers have been proposed.

However, conventional photosensitive lithographic printing plates using diazo resins, such as conventional negative PS plates, have problems in storage stability. For example, the developability of a photosensitive lithographic printing plate after long-term storage may deteriorate, resulting in stains on printed matter obtained from the printing plate after development. Such deterioration in storage and developability is undesirable, and it is desirable to be able to stably obtain good printed matter even when exposed and developed after long-term storage.

[Purpose of the invention]

The object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a photosensitive composition having good storage stability and particularly good storage developability, which prevents deterioration of developability after storage, and The aim is to provide lithographic printing plates.

[Means and effects for solving the problem 3 The invention according to claim 1 of the present application is a photosensitive composition characterized by containing a diazo resin, an alkali-soluble/swellable polymer compound, and a radical scavenger. This structure achieves the above object.

The invention according to claim 2 of the present application is a photosensitive lithographic printing plate having a diazo resin, an alkali-soluble/swellable polymer compound, and a radical scavenger on a support, and with this structure, the above object is achieved. This has been achieved.

In the present invention, the alkali-soluble/swellable polymer compound refers to an alkali-soluble and/or swellable polymer compound, and includes an alkali-soluble polymer compound, an alkali-swellable polymer compound, and an alkali-soluble and alkali-swellable polymer compound. This is a general term for the concept that includes chemical polymer compounds.

Further, in the present invention, a radical scavenger refers to an agent capable of scavenging radicals generated as a component of a photosensitive composition etc. changes over time, for example, as a diazo resin changes over time.

The inventors of the present invention have conducted various studies and experiments from among a huge group of substances, and have found a substance that meets the purpose of the present invention, resulting in the present invention.The above structure has achieved the purpose of the present invention. What happened was unexpected even for the inventors.

The present invention will be further explained below.

First, the diazo resin contained in the photosensitive composition of the present invention and included in the photosensitive lithographic printing plate of the present invention will be described.

The above diazo resin is used as a photosensitive substance.

Any diazo resin can be used in the present invention.

In the present invention, as the diazo resin, a co-condensed diazo resin containing an aromatic compound having one or more of at least one of a carboxyl group or a hydroxyl group and an aromatic diazonium compound as a constituent unit can be preferably used.

Such an aromatic compound having a carboxyl group and/or a hydroxyl group is one that contains an aromatic ring substituted with at least one carboxyl group and/or an aromatic ring substituted with at least one hydroxyl group in the molecule. In this case, the carboxyl group and hydroxyl group may be substituted on the same aromatic ring, or may be substituted on different aromatic rings. It may be bonded directly to the ring (or may be bonded via a bonding group).

Preferred examples of the aromatic group include aryl groups such as phenyl and naphthyl groups.

In the co-condensed diazo resin that can be used in the present invention, the number of carboxyl groups bonded to one aromatic ring is preferably 1 or 2, and the number of hydroxyl groups bonded to one aromatic ring is 1 to 3. When a carboxyl group or a hydroxyl group is preferably bonded to an aromatic ring via a bonding group, examples of the bonding group include an alkylene group having 1 to 4 carbon atoms.

Specific examples of the aromatic compound containing a carboxyl group and/or hydroxyl group as a constitutional unit of the co-condensed diazo resin include benzoic acid, O-chlorobenzoic acid, m-
Chlorobenzoic acid, p-chlorobenzoic acid, phthalic acid, terephthalic acid, diphenylacetic acid, phenoxyacetic acid, p-methoxyphenylacetic acid, p-methoxybenzoic acid, 2.4-dimethoxybenzoic acid, 2.4-dimethylbenzoic acid, p-phenoxybenzoic acid, 4-anilinobenzoic acid, 4-(m-
methoxyanilino)benzoic acid, 4-(p-methylbenzoyl)benzoic acid, 4-(p-methylanilino)benzoic acid, 4-phenylsulfonylbenzoic acid, phenol, (o
, m, p)-cresol, xylenol, resorcinol,
2-Methylresorcin, (o,m,p)-methoxyphenol, m-ethoxyphenol, catechol, phloroglycin, p-hydroxyethylphenol, naphthol, pyrogallol, hydroquinone, p-hydroxybenzyl alcohol, 4-chlororesorcin, biphenyl −
4,4°-diol, l, 2°4-benzenetriol, bisphenol A12°4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, p
-Hydroxyacetophenone, 4.4-dihydroxydiphenyl ether, 4.4'-dihydroxydiphenylamine, 4.4°-dihydroxydiphenyl sulfide, cumylphenol, (o, m, p) -chlorophenol, (o, m, p) -bromophenol, salicylic acid, 4-methylsalicylic acid, 6-methylsalicylic acid, 4-ethylsalicylic acid, 6-propylsalicylic acid, 6
-Laurylsalicylic acid, 6-styarylsalicylic acid, 4
, 6-dimethylsalicylic acid, p-hydroxybenzoic acid,
2-methyl-4-hydroxybenzoic acid, 6-methyl-4
-Hydroxybenzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 2.4-dihydroxybenzoic acid, 2.4
-dihydroxy-6-methylbenzoic acid, 2゜6-dihydroxybenzoic acid, 2,6-cyhydroxy-4-benzoic acid, 4-chloro-2,6-dihydroxybenzoic acid, 4-methoxy-2,6-dioxybenzoic acid , gallic acid, phloroglucincarboxylic acid, 2.4.5-) dihydroxybenzoic acid, m-galloyl gallic acid, tannic acid, m-benzoyl gallic acid, m-(1)-tolyl) gallic acid, protocatechuoi Ru-gallic acid, 4,6-dihydroxyphthalic acid, (2,4-dihydroxyphenyl) vinegar 9, (2,
6-dihydroxyphenyl)acetic acid, (3,4,5-trihydroxyphenyl)acetic acid, p-hydroxymethylbenzoic acid, p-hydroxyethylbenzoic acid, 4-(p-hydroxyphenyl)methylbenzoic acid, 4-(0 -hydroxybenzoyl)benzoic acid, 4-(2,4-dihydroxybenzoyl)benzoic acid, 4-(p-hydroxyphenoxy)benzoic acid, 4-(p-hydroxyanilino)benzoic acid, bis(3-carboxy-4 -hydroxyphenyl)amine, 4-(p-hydroxyphenylsulfony),
)benzoic acid, 4-(p-hydroxyphenylthio)
Examples include benzoic acid. Among these, particularly preferred are salicylic acid, p-hydroxybenzoic acid, p-
Methoxybenzoic acid and metachlorobenzoic acid.

As the aromatic diazonium compound used as the structural unit of the co-condensed diazo resin, diazonium salts such as those listed in Japanese Patent Publication No. 49-48001 can be used, but diphenylamine-4-diazonium salts are particularly preferred. Diphenylamine-4-diazonium salts are
Although derived from 4-amino-diphenylamines, such 4-amino-diphenylamines include 4-amino-diphenylamines.
-Amino-diphenylamine, 4-amino-3-methoxy-diphenylamine, 4-amino-2-methoxy-diphenylamine, 4'-amino-2-methoxy-diphenylamine, 4'-amino-4-methoxydiphenylamine, 4-amino- 3-methyldiphenylamine,
4-amino-3-ethoxy-diphenylamine, 4-amino-3-β-hydroxy-ethoxydiphenylamine, 4-amino-diphenylamine-2-sulfonic acid, 4
Examples include -amino-diphenylamine-2-carboxylic acid and 4-amino-diphenylamine-2'-carboxylic acid. Particularly preferred are 3-methoxy-4-amino-diphenylamine, 4-amino-1, "A, -
/ The co-condensed diazo resin that can be used in the present invention is preferably one represented by the following general formula (1).

In the general formula (1), A is a group derived from an aromatic compound having at least one of a carboxyl group and a hydroxyl group, and examples of such aromatic compounds include those exemplified above.

In the formula, Rt, Rt and R1 represent a hydrogen atom, an alkyl group or a phenyl group, R represents a hydrogen atom, an alkyl group or a phenyl group, and X represents a counter anion. n preferably represents a number from 1 to 200.

When a co-condensed diazo resin is used in the present invention, it is more preferable to use it in combination with a condensed diazo resin obtained by condensing an aromatic diazonium compound.

In this case, the co-condensed diazo resin is preferably used in an amount of 5% by weight or more in the diazo resin, and the condensed diazo resin is preferably used in an amount of 95% by weight or less in the diazo resin.

Further, in this case, the weight % ratio of co-condensed diazo resin to condensed diazo resin is particularly preferably 30-70, nia 0-30, from the viewpoint of providing excellent anger and developability.

The above-mentioned co-condensed diazo resins and condensed diazo resins used in combination with these or independently as diazo resins are:
Known methods such as Photographic Science and Engineering (Photo, Sci, E.
ng, ) Volume 17, Page 33 (1973), U.S. Patent No. 2.063.631 and U.S. Patent No. 2.679.498. It can be obtained by polycondensing salts, aromatic compounds having carboxyl and hydroxyl groups, and aldehydes, such as paraformaldehyde, acetaldehyde, benzaldehyde, or yoketones, such as acetone and acetophenone.

Furthermore, these aromatic compounds, aromatic diazo compounds, and aldehydes or ketones having carboxyl and/or hydroxyl groups in their molecules can be freely combined with each other, and two or more of each may be mixed and co-condensed. is also possible.

The molar ratio of the aromatic compound having at least one of a carboxyl group and a hydroxyl group to the aromatic diazonium compound is preferably 1:0.1-0.1:1.
, more preferably 1:0.5 to 0.2=1, still more preferably 1:1 to 0.21.

In this case, the molar ratio of the sum of aromatic compounds and aromatic diazonium compounds having at least one of a carboxyl group and a hydroxyl group to aldehydes or ketones is usually preferably l: 0.6 to 1.2, more preferably A co-condensed diazo resin can be obtained by mixing the components at a ratio of 1:0.7 to 1.5 and reacting at a low temperature for a short period of time, for example, about 3 hours.

The counter anion of the diazo resin includes an anion that stably forms a salt with the diazo resin and makes the resin soluble in an organic solvent.Those that form such anions include decanoic acid and benzoic acid. and organic carboxylic acids such as benzoic acid, organic phosphoric acids such as phenylphosphoric acid, and sulfonic acids. Typical examples include methanesulfonic acid, chloroethanesulfonic acid, dodecanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, Mesitylene sulfonic acid, and aliphatic and aromatic sulfonic acids such as anthraquinone sulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, hydroxysulfonic acid, 4-acetylbenzenesulfonic acid, and dimethyl-5-sulfoisophthalate. , 2゜2'', 4.4'-tetrahydroxybenzophenone, 1.2.3-)lihydroxybenzophenone, hydroxyl group-containing aromatic compounds such as 2.2゜,4-trihydroxybenzophenone, hexafluorophosphoric acid, tetra Halogenated Lewis acids such as fluoroboric acid, Cl
Examples include perhalogen acids such as O4 and [04. However, it is not limited to this.

Among these, particularly preferred are hexafluorophosphoric acid and tetrafluoroboric acid.

The above-mentioned co-condensed diazo resin can have an arbitrary molecular weight by varying the molar ratio of each monomer and the condensation conditions. In the present invention, in general, those having a molecular weight of about 400 to 10,000 can be effectively used, more preferably about 800 to 10,000 s, ooo
is appropriate.

In addition, in the present invention, other than the above-mentioned co-condensed diazo resins, those which can be preferably used as diazo resins include, for example, the above-mentioned Photographic Ink Science & Co., Ltd.
Engineering (Photo.

SciJng, Volume 17, Page 33 (1973),
U.S. Patent Nos. 2,063,631 and 2,679,49
No. 8, 3゜050.502 specifications, JP-A-59-
A diazo resin obtained by condensing a diazo compound and an active carbonyl compound, such as formaldehyde, acetaldehyde, or benzaldehyde, etc., in an acidic medium such as sulfuric acid, phosphoric acid, or hydrochloric acid, the manufacturing method of which is described in Publication No. 78340, etc. Examples include diazo compounds and diphenyl resins whose production methods are described in Publication No. 49-4001.

Among the above, the diazo resin that can be preferably used in the present invention is represented by the following general formula (U) and contains 20 mol% or more of a resin in which n in each formula is 5 or more, more preferably 20 mol% or more. It contains ~60 mol%. In the formula, R
1 to R,, R, X, and n have the same meanings as in the general formula (1). In general formula (II), R1+
As the alkyl group and alkoxy group of Rz and R3,
Examples include an alkyl group having 1 to 5 carbon atoms and an alkoxy group having 1 to 5 carbon atoms, and examples of the alkyl group for R include an alkyl group having 1 to 5 carbon atoms. 'Following margin j General formula (II) Such a photosensitive diazo resin can be manufactured according to a known method, for example, the method described in the above-mentioned Photographic Science and Engineering and other U.S. patent specifications cited above. can do.

At that time, when polycondensing the diazonium salt and the aldehyde, the molar ratio of both is usually i:o, 6 to 1:
2. A high-sensitivity diazo resin can be obtained by charging preferably at a ratio of 1:0.7 to 1:1.5 and reacting at a low temperature for a short period of time, for example, 10° C. or less for about 3 hours.

Examples of the counter anion of the diazo resin represented by the -S formula (II) include the same counter anions as those listed for the co-condensed diazo resin.

Next, the alkali-soluble/swellable polymer compound contained in the photosensitive composition of the present invention and that the photosensitive lithographic printing plate of the present invention has will be explained. This polymer compound can function as a binder when forming a photosensitive composition or a photosensitive layer and/or a colored layer of a photosensitive lithographic printing plate.

In the present invention, the alkali-soluble/swellable polymer compound is one that is alkali-soluble, alkali-swellable, or has both properties. One or more kinds of such polymer compounds can be arbitrarily used.

In the present invention, the term "alkali-soluble" refers to a substance that dissolves into an alkaline solution, for example, an alkaline solution having a pH of 12.0 or higher at 25°C. In addition, the term "alkali swelling property" refers to a property in which the volume expands when a liquid permeates in an alkaline solution, and when it is coated on a support, it becomes easy to peel off from the support.

Any alkali-soluble/swellable polymer compound as described above can be used in the present invention.

In addition, in carrying out the present invention, in order to specify the molecular weight of the polymer compound used, the value of the molecular weight measured by GPC using a polystyrene standard can be used.

That is, the weight average molecular weight can be measured by GPC (gel permeation chromatography), and the number average molecular weight fiMN and weight average molecular weight MW can be calculated according to the method written by Morio Tsuge, Tatsuya Miyabayashi, and Masayuki Tanaka. This can be carried out by leveling the peaks of the oligomer region (connecting the center lines of the peaks and valleys) according to the method described in "Journal of the Chemical Society of Japan," pages 800 to 805 (1972).

The polymer compound that can be used in the present invention may be of any type as long as it is alkali-soluble and swellable as described above, and for example, the following compounds can be used. That is, the polymer compounds that can be used include polyamide, polyether polyester, polycarbonate,
Examples include polystyrene polyurethane, polyvinyl chloride and copolymers thereof, polyvinyl butyral resin, polyvinyl) Lt, h2/L/marl resin, shellac, epoxy resin, phenol resin, acrylic resin, and the like.

Preferably, copolymers of the monomers shown in (1) to (12) below, which are alkali-soluble and swellable polymer compounds, are preferred. .

The rest: , j°±゛, . . . (1) Seven polymers having an aromatic hydroxyl group, for example, N
, -(4-hydroxyphenyl)acrylamide or N-(4-hydroxyphenyl)methacrylamide, o-, m-, p-hydroxystyrene, o-, m-,
p-Hydroxyphenyl-acrylate or -methacrylate.

(2) Monomers having aliphatic hydroxyl groups, such as 2-hydroxyethyl acrylate or 2,2-hydroxyethyl methacrylate.

(3) α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and maleic anhydride.

(4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, acrylic acid-
(Substituted) alkyl acrylates such as 2-chloroethyl, 2-hydroxyethyl acrylate, glycidyl acrylate, and N-dimethylaminoethyl acrylate.

(5) Methyl methacrylate, ethyl methacrylate,
Probyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 2
-Hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-
(Substituted) alkyl methacrylates such as dimethylaminoethyl methacrylate.

(6) Acrylamide, methacrylamide, N-methylol acrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-hexylacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenyl Amide, N-ethyl-N-
Acrylamides or methacrylamides such as phenylacrylamide.

(7) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, droxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.

(8) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, and vinyl benzoate.

(9) Styrenes such as styrene, α-methylstyrene, methylstyrene, and chloromethylstyrene.

(lO) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.

(11) Olefins such as ethylene, propylene, inbutylene, butadiene, and isoprene.

(12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylamide, etc.

Furthermore, a monomer that can be copolymerized with the above monomer may be copolymerized. Further, the copolymerization pair obtained by copolymerization of the above monomers may be, for example, glycidyl methacrylate,
It also includes, but is not limited to, those modified with glycidyl acrylate and the like.

More specifically, a copolymer having a hydroxyl group containing the heptamers listed in (1) and (2) above is preferred, and a copolymer having an aromatic hydroxyl group is even more preferred.

Further, polyvinyl butyral resin, polyurethane resin, polyamide resin, epoxy resin, novolac resin, natural resin, etc. may be added to the above copolymer as necessary.

Particularly preferred as the copolymer which is the alkali-soluble/swellable polymer compound used in the present invention are the following copolymers.

That is, in the molecular structure, (a) 1 to 50 mol% of a structural unit having an alcoholic hydroxyl group and/or a structural unit having a phenolic hydroxyl group, (b) the following general formula IA - CHt -C-... ...IAN (wherein R11 represents a hydrogen atom or an alkyl group.

) 5 to 40 mol% of the structural unit represented by (c) the following general formula IIA RIZ -CH2-C- mAC0OR" (where RIZ is a hydrogen atom, a methyl group or A polymer compound containing 25 to 60 mol% of a structural unit represented by (representing an ethyl group, and R11 represents an alkyl group having 2 to 12 carbon atoms or an alkyl-substituted aryl group) is preferable, and its weight average Molecular weight is 20,000~
Even more preferred are copolymers with a molecular weight of 200.000.

As a specific example of the seven-termer forming the structural unit having an alcoholic hydroxyl group in (a) above, Japanese Patent Publication No. 52-736
Examples include (meth)acrylic acid esters and acrylamides such as the compounds shown in the following general formula 1 [IA] as described in No. 4.

Margin CH below! -C-...InAC00+CH
2C■10+ir-■IS In the formula, RI4 represents a hydrogen atom or a methyl group, R1% represents a hydrogen atom, a methyl group, an ethyl group, or a chloromethyl group, and n represents an integer of 1-10.

Examples of (meth)acrylic acid esters include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-bitroxypentyl (meth)acrylate, and examples of acrylamides include , N-methylol (meth)acrylamide,
Examples include N-hydroxyethyl (meth)acrylamide and the like.

Preferably it is 2-hydroxyethyl (meth)acrylate.

In addition, examples of monomers forming the structural unit having a phenolic hydroxyl group (a) include N-(4-hydroxyphenyl)-(meth)acrylamide, N-(
2-hydroxyphenyl)-(meth)acrylamide,
(meth)acrylamide monomers such as N-(4-hydroxynaphthyl)-(meth)acrylamide; O-,
Examples include m- or p-hydroxyphenyl (meth)acrylate monomer; O-, m- or p-hydroxystyrene monomer. Preferably they are O-lm- or p-hydroxyphenyl (meth)acrylate monomers, N-(4-hydroxyphenyl)-(meth)acrylamide monomers, and more preferably N-(4-
Hydroxyphenyl)-(meth)acrylamide monomer.

The structural unit having an alcoholic hydroxyl group and/or the structural unit having a phenolic hydroxyl group is preferably 1 to 50 mol%, more preferably 5 to 50 mol%, in the polymer compound.
It is selected from a range of 30 mol%.

Examples of monomers having a cyano group in the side chain that form the structural unit represented by the general formula IA include acrylonitrile, methacrylonitrile, 2-pentenenitrile, and 2-pentenenitrile.
Methyl-3-butenenitrile, 2-cyanoethyl acrylate, o-, m-.

Examples include p-cyanostyrene. Preferred are acrylonitrile and methacrylonitrile.

The proportion of the structural unit having a cyano group in the side chain contained in the molecule of the polymer compound is preferably selected from the range of 5 to 40 mol%, more preferably 15 to 35 mol%.

The monomer having a carboxy ester group in the side chain and forming the structural unit represented by the general formula IIA is as follows:
Examples include ethyl acrylate, ethyl methacrylate, propyl acrylate, butyl acrylate, amyl acrylate, amyl methacrylate, hexyl acrylate, octyl acrylate, 2-chloroethyl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, and the like. The units formed from supranuclear units are preferably 25 to 6 in the polymer compound.
It is selected from the range of 0 mol%, more preferably from 35 to 60 mol%.

In addition, the above-mentioned preferred polymer compound has, in its molecular structure,
It may contain, for example, 2 to 30 mol% of a structural unit having a carboxyl group.

Examples of the seven polymers forming the structural unit having a carboxyl group include methacrylic acid, acrylic acid, maleic anhydride, and maleic acid. The hexamer is selected from the range of 2 to 30 mol%, preferably 5 to 15 mol% in the polymer compound.

In addition, each of the above-mentioned structural units is not limited to the unit formed from the heptadium mentioned as a specific example.

In the present invention, the alkali-soluble/swellable polymer compound is
In the solid content of the photosensitive composition and in the solid content constituting the photosensitive layer on the support, preferably 40 to 99% by weight,
More preferably, it is contained in an amount of 50 to 95% by weight. Further, in the present invention, the photosensitive diazo resin is preferably contained in an amount of usually 1 to 60% by weight, more preferably 3 to 30% by weight.

Next, the radical scavenger contained in the photosensitive composition of the present invention and that the photosensitive lithographic printing plate of the present invention has will be explained.

In the present invention, as the radical scavenger, for example, those commonly used as antioxidants, polymerization inhibitors, chain transfer agents, quenchers, etc. can be used.

The radical scavenger contained in the photosensitive composition of the present invention is preferably 0.01 to
The content is preferably 10% by weight, more preferably 0.1 to 5% by weight.

Further, in the photosensitive lithographic printing plate of the present invention, it is preferable that the radical scavenger is contained in the photosensitive layer, and in that case,
The solid content of the photosensitive composition constituting the photosensitive layer preferably contains 0.01 to 10% by weight, more preferably 0.1 to 5% by weight.
It is better to include % of heavy background.

Examples of radical scavengers that can be preferably used in carrying out the present invention include the following. For commercially available products, the product name is shown in parentheses after the chemical name.

Namely, 2.6-di-t-butyl-p-cresol (Yoshinox B IT, manufactured by Yoshitomi Pharmaceutical), butylhydroxyanisole (BIIA-wakos, manufactured by Wako Pure Chemical Industries), 2.6-di-t-butyl-4-ethyl. Phenol (Yoshinox 25
0, Yoshitomi Pharmaceutical), stearyl-β-(3,5-di-t
-Butyl-4-hydroxyphenyl) propionate (Tominox ss, manufactured by Yoshitomi Pharmaceutical), 2,2'-methylene-bis-(4-methyl-6-t-butylphenol) (Yoshinox 2246 G, manufactured by Yoshitomi Pharmaceutical), 2 .2
゛-Methylene-bis-(4-methyl-6-t-butylphenol) (Yoshinox 425, manufactured by Yoshitomi Pharmaceutical), 4.4゛-Thiobis-(3-methyl-6-t-butylphenol) (Yoshinox SR1 manufactured by Yoshitomi Pharmaceutical) ), 4.4′-butylidene-bis-(3-methyl-6-t-
butylphenol) (Yoshinox Bll, manufactured by Yoshitomi Pharmaceutical), 1,1.3-
) Lis-(2-methyl-4-hydroxy-5-t-butylphenyl)butane (manufactured by Topanol CA, 1.C,r), 1.3.
5- ) dimethyl-2,4,6-dolys(3,5-di-t-butyl-4-hydroxybenzyl)benzene) (Ionox 330, shell chemistry), tetrakis-[methylene-3-(3°, 5°-di-t-butyl-4
°-Hydroxyphenyl) propionate comethane (Irganox 1010% manufactured by Nippon Ciba Gaiki), bis(3,3'-bis-(4°-hydroxy-3°-t)
-butylphenyl)butyrin acid coglycol ester (antioxidant Hoechst)
TMOZ% Hoechs), α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, erythorbic acid, sodium erythorbate, guaiac butter, nordihydroguaiaretic acid, propyl gallate, 2,5-tocopherol Monobutylhydroquinone, 2.5-di-L-amylhydroquinone, p-benzoquinone, chloranil, N, N, N', N'-tetraethyl-p-phenylenediamine, methoquinone, picric acid, didiobenzoyl disulfide, p, p'-ditolyltolyl sulfide, p, p'-ditolyl tetrasulfide, dibenzyl tetrasulfide, tetraethylthiuram disulfide, α, α-diphenyl-β-picrylhydrazine, α, α
- Diphenyl-β-picrylhydrazyl, diphenylamine, hydroquinone, p-t-butylcatechol, nitrobenzene, galpinoxyl, N-(3-N-oxyanilino-1,3-dimethylbutylidene)aniline oxide, p, p'-difluoro diphenylamine, )'J −
p-nitrophenylmethyl, 1.3.5-)riphenylferdazyl, 2.2,6.6-tetramethyl-4-
Piperidone-1-oxyl, nitrosobenzene, anthracene, pyrene, 4-phenylbenzophenone, benzophenone, butyrophenone, thioglycolic acid, urea, 5-sulfanilic acid, 0-sulfobenzoic anhydride, p-)luenesulfonic acid, benzenesulfonic acid , sulfophthalic acid, sulfanilic acid, O-sulfobenzoic acid, ammonium O-sulfobenzoate, 5-sulfoisophthalic acid, sodium 5-sulfoisophthalate, m-sulfobenzoic acid, sodium m-sulfobenzoate, etc. be able to.

The photosensitive composition of the present invention or the photosensitive layer of the photosensitive lithographic printing plate of the present invention may contain an acid and/or an acid anhydride.

When using an acid, it can be arbitrarily selected from any organic acid or inorganic acid. The organic acid is preferably a monocarboxylic acid or a polycarboxylic acid having at least one carboxyl group. Malic acid, tartaric acid, and polyacrylic acid (such as those commercially available under the trade name Jurimer) can be preferably used. Also, organic acids (citric acid, oxalic acid, benzenesulfonic acid, naphthalenesulfonic acid, 4-
methoxy-2-hydroxybenzophenone-5-sulfonic acid, etc.) can also be used. As the a-free acid, phosphoric acid, phosphorous acid, etc. can be used. These acids can also function as stabilizers.

When using an acid anhydride, the type of acid anhydride is arbitrary, and examples include those derived from aliphatic/aromatic monocarboxylic acids such as acetic anhydride, propionic anhydride, and benzoic anhydride, succinic anhydride, and maleic anhydride. Examples include those derived from aliphatic/aromatic dicarboxylic acids such as acids, glutaric anhydride, phthalic anhydride, and the like.

The photosensitive material composition of the present invention or the photosensitive lithographic printing plate of the present invention may contain a dye, particularly a dye that changes color from color to colorless or changes color upon processing. Preferably, a pigment that changes from colored to colorless is contained. The dye contained in the photosensitive lithographic printing plate may be contained in the photosensitive layer to form a colored photosensitive layer, or may be contained in a colored layer separate from the photosensitive layer.

In carrying out the present invention, the following can be mentioned as dyes that can be preferably used.

That is, for example, Victoria Pure Blue B OH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), Crystal Violet, Brilliant Green,
Ethyl violet, methyl violet, methyl green, erythrosin B1 basic tsuksin, malachite green, oil red, m-cresol purple,
Triphenylmethane type, diphenylmethane type, oxazine type, xanthine type, iminonaphthoquinone type, azomethine type or anthraquinone represented by rhodamine B, auramine, 4-p-dimethylaminophenyliminonaphthoquine, cyano-p-diethylaminophenyl acetanilide, etc. Examples of pigments that change color from colored to colorless or to a different color can be cited.

Particularly preferred are triphenylmethane-based and diphenylmethane-based dyes, more preferably triphenylmethane-based dyes, and Victoria Viewer Blue BOH is particularly preferred.

The above-mentioned color changing agent is preferably contained in the photosensitive composition or the photosensitive layer in an amount of usually about 0.5 to about 10% by weight, more preferably about 1 to 5% by weight.

In the present invention, various additives can be further added.

Examples of additives include alkyl ethers (e.g., ethyl cellulose, methyl cellulose), fluorine surfactants, and nonionic surfactants (e.g., Pluronic L-64 (manufactured by Asahi Denka Corporation) to improve coating properties).
], a plasticizer to impart flexibility and abrasion resistance to the coating film (
For example, butyl phthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid. (oligomers and polymers), and oil-sensitizing agents for improving the oil-sensitivity of image areas (for example, a halfester compound of styrene-anhydride maleic H-co-M combination with alcohol described in JP-A-55-527), etc. It will be done. The amount of mold added to these additives varies depending on the target and purpose of use, but is generally preferably 0.01% based on the total solid content.
~30% by weight.

In order to obtain the photosensitive lithographic printing plate of the present invention, for example, predetermined amounts of a diazo resin, an alkali-soluble/swellable compound, a cellulose compound, and, if necessary, various additives are mixed in a suitable solvent (methyl cellosolve, ethyl Cellosolve, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethyl formamide, dimethyl sulfoxide, water or a mixture thereof, etc.) is dissolved in a coating solution of the photosensitive composition, which is coated on a support and dried. It can be obtained as a printed version. The concentration of the photosensitive composition during coating is preferably in the range of 1 to 50% by weight. In this case, the coating amount of the photosensitive composition is preferably about 0.2 to 10 g/m.

In carrying out the present invention, the photosensitive lithographic printing plate may have a structure having a colored photosensitive layer made of a photosensitive composition containing a dye, or a photosensitive layer made of a colored layer made of a dye or other binder and a photosensitive composition. It may be configured to have two layers. When having two layers, either layer may be placed on the support side.

In the photosensitive planographic printing plate of the present invention, as a support,
Various types can be used. Particularly preferred is an aluminum plate. However, if an aluminum plate is used without treatment, there are problems in that the adhesion of the photosensitive composition is poor and the photosensitive composition decomposes. To eliminate this problem,
Conventionally, various proposals have been made.

For example, a method in which the surface of an aluminum plate is grained and then treated with a silicate (US Pat. No. 2.714°066), a method in which the surface is treated with an organic acid salt (US Pat. No. 2.714,
No. 066), treatment with phosphonic acids and their derivatives (U.S. Pat. No. 3,220,832), treatment with potassium hexafluorozirconate (U.S. Pat. No. 2
, 946.683), a method of anodic oxidation, and a method of treatment with an aqueous solution of alkali metal silicate after anodization (US Pat. No. 3,181.461).

In preferred embodiment B of the present invention, the surface of the aluminum plate (including the alumina laminate; the same applies hereinafter) is degreased and then grained by a brush polishing method, a ball polishing method, a chemical polishing method, an electrolytic etching method, etc. It is preferably grained using an electrolytic etching method that produces deep and uniform grains.

The anodizing treatment is carried out, for example, in an aqueous solution of an inorganic salt such as phosphoric acid, chromic acid, boric acid, or sulfuric acid, or an organic acid such as oxalic acid, or a mixture of two or more of these acids, preferably in an aqueous sulfuric acid solution. This is done by passing an electric current through an aluminum plate as an anode. The amount of anodic oxide film is 5-6
0■/drrr is preferable, more preferably 5 to 30■
/drrr.

When carrying out sealing treatment in carrying out the present invention, preferably a sodium silicate aqueous solution with a concentration of 0.1 to 3% is added at a temperature of 8.
This treatment is carried out by immersion at 0 to 95° C. for lθ seconds to 2 minutes.

More preferably, it is then soaked in water at a temperature of 40 to 95°C for 10 seconds to 2
Soak and process for a minute.

The photosensitive lithographic printing plate of the present invention can be exposed and developed by conventional methods. ! II. For example, by exposing a transparent original having a line image, halftone image, etc. to light and then developing with an aqueous developer, a negative leaf image can be obtained for the original.

Light sources suitable for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, and the like.

Any method can be used to develop the image-exposed photosensitive lithographic printing plate (hereinafter sometimes referred to as "RPS plate"), and for example, various conventionally known methods can be used.

Specifically, methods include immersing an image-exposed PS plate in a developer, spraying the developer from multiple nozzles onto the photosensitive layer of the PS plate, and exposing the PS plate using a sponge moistened with the developer. Various methods can be used, such as wiping the layer and applying a developer to the surface of the photosensitive layer of the PS plate with a roller. Further, after applying the developer to the photosensitive layer of the PS plate in this manner, the surface of the photosensitive layer can be lightly rubbed with a brush or the like.

Any developer can be used to develop the photosensitive composition of the present invention and/or the photosensitive lithographic printing plate of the present invention, as long as it can develop the composition.

Preferably, a developer containing a specific organic solvent, an alkaline agent, and water as essential components can be used.

The specific organic solvent used herein refers to an organic solvent that can dissolve or swell the non-exposed area (non-image area) of the layer made of the photosensitive composition when it is contained in the developing solution, and that can be used at room temperature ( Solubility in water is 10% by weight at 20℃)
The following organic solvents are preferred. Such organic solvents only need to have the characteristics described above, and are not limited to the following, examples of which include ethyl acetate, propyl acetate, etc. , butyl acetate, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl acetate, butyl levulinate; ketones such as ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone; ethylene glycol monobutyl ether, ethylene Alcohols such as glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol; alkyl-substituted aromatic hydrocarbons such as xylene; methylene dichloride, ethylene dichloride, mono Examples include hydrogen halides such as chlorobenzene.

These organic solvents may be used alone or in combination of two or more. Among these organic solvents, ethylene glycol monophenylnitere and benzyl alcohol are particularly effective. Further, the content of these organic solvents in the developer is preferably approximately 1 to 20% by weight,
In particular, more preferable results are obtained when the amount is 2 to 10% by weight.

On the other hand, preferred alkaline agents contained in the developer include (A) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, di- or tri-sodium phosphate or ammonium salt; Inorganic alkaline agents such as sodium metasilicate, sodium carbonate or ammonium, (B) mono, di or trimethylamine, mono.

Examples include organic amine compounds such as di- or triethylamine, mono- or diisopropylamine, n-butylamine, mono-di- or triethanolamine, mono-, di- or tri-isopropanolamine, ethyleneimine, ethylenediamine, and the like.

The content of these alkaline agents in the developer is usually 0.
It is preferably 0.05 to 4% by weight, more preferably 0.5 to 2% by weight.

Further, in order to further improve storage stability, rigidity resistance, etc., it is preferable to include a water-soluble sulfite in the developer. Such water-soluble sulfites are preferably alkali or alkaline earth metal salts of sulfite, such as sodium sulfite, potassium sulfite, lithium sulfite, magnesium sulfite, and the like. The content of these sulfites in the developer composition is usually preferably 0.05 to 4% by weight, more preferably 0.1 to 1% by weight.

If such a developer is brought into contact with the photosensitive composition and/or the photosensitive lithographic printing plate after development and exposure, or is rubbed with the developer, the reaction time will be approximately 10 to 40°C at room temperature to 40°C.
After 60 seconds, the photosensitive composition in the non-exposed areas of the photosensitive composition layer is completely removed without adversely affecting the exposed areas of the photosensitive composition layer.

The developing conditions can be appropriately selected depending on the developing method. - For example, in the development method by immersion, a method of immersing the film in a developer solution at about 10 to 40° C. for about 10 to 80 seconds can be used.

・,’:,7・,.

Margin below 111. .

,'. [Examples] Examples of the present invention will be described below. As a matter of course, the present invention is not limited to the following examples.

Prior to specific description of Examples, the polymer compound and diazo resin used in each Example will be explained.

Official A(1) A N-(4-hydroxyphenyl)methacrylamide 1
7.7g, methacrylic acid 8.6g, acrylonitrile 10.6g, ethyl acrylate 60.0g
.

and 1.64 g of azobisisobutyronitrile were dissolved in 130 ml of an acetone-methanol 1:l mixed solution, the atmosphere was purged with nitrogen, and the mixture was heated at 60° C. for 6 hours.

After the reaction is completed, the reaction solution is mixed with 51.1 liters of water. The resulting white precipitate was filtered and dried to obtain 87 g of polymer compound (1).
Obtained.

When the molecular weight of this polymer compound (11) was measured by gel permeation chromatography (hereinafter abbreviated as GPC, polystyrene standard), the weight average molecular weight was 82.000.

1ゝ　A(2)-8 2-hydroxyethyl methacrylate 13.0g.

Methacrylic acid 8.6g, acrylonitrile 10.6g
g2 60.0 g of ethyl acrylate and 1.64 g of azobisisobutyronitrile were dissolved in 130 mj+ of an acetone-methanol 1:l mixed solution, the atmosphere was purged with nitrogen, and the mixture was heated at 60° C. for 6 hours.

Thereafter, in the same manner as for polymer compound (1), 83 g of polymer compound (2) was obtained.

When the molecular weight of this polymer compound (2) was measured by GPC, the weight average molecular weight was 67.000.

14.5 g of A p-diazodiphenylamine sulfate of diazo 4'l was dissolved in 40 g of concentrated sulfuric acid under water cooling. 1.05 g of paraformaldehyde was slowly added to the reaction solution. At this time, the addition was carried out so that the reaction temperature did not exceed 10°C. Thereafter, stirring was continued for 2 hours under water cooling. This reaction mixture was added dropwise to 500 ml of ethanol under water cooling, and the resulting precipitate was filtered off.

After washing the precipitate with ethanol, the precipitate was dissolved in 100-pure water, and to this solution was added an aqueous solution in which 6.8 g of zinc chloride was dissolved. The resulting precipitate was filtered off, washed with ethanol, and dissolved in 150 ml of pure water. To this liquid, an aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved was added, and the resulting precipitate was filtered, washed with water and ethanol, and then dried at 25°C for 3 days to obtain diazo resin 1. .

Diazo 482 human p-diazodiphenylamine sulfate 21.75g and p-hydroxybenzoic acid 3.5g were cooled in water to give 90g.
of concentrated sulfuric acid. To this reaction solution, 2.7 g of paraformaldehyde was slowly added.

At this time, the addition was carried out so that the reaction temperature did not exceed 10°C. Thereafter, stirring was continued for 2 hours under water cooling.

This reaction mixture was added dropwise to 1 liter of ethanol under water cooling, and the resulting precipitate was filtered off. After washing the precipitate with ethanol, transfer the precipitate to 200 m 7! of pure water, and to this solution was added an aqueous solution containing 10.5 g of zinc chloride. After filtering the resulting precipitate, it was washed with ethanol and
It was dissolved in ml of pure water. An aqueous solution in which 13.7 g of ammonium hexafluorophosphate was dissolved was added to this solution, and the resulting precipitate was filtered, washed with water and ethanol, and dried at 25°C for 3 days to obtain the diazo resin 2. I got it.

Next, examples will be described together with comparative examples.

Example 1 and Comparative Example 1 A photosensitive solution having the following composition (1) was applied to an anodized aluminum plate in a grain chamber until the coating weight after drying was 20.
A photosensitive lithographic printing plate sample was prepared by coating at a ratio of 1/dI of 112.

Composition (1) Medium radical scavenger: 2.2'-methylene-bis-(4-
Methyl-5-t-butylphenol) (Product name Yoshinox 2246G.

(manufactured by Yoshitomi Pharmaceutical Co., Ltd.) As Comparative Example 1, a photosensitive lithographic printing plate sample was used which was coated in the same manner as described above using the photosensitive liquid composition (1) except that the radical scavenger was removed.

A negative transparent original image was placed on the obtained sample and exposed for 30 seconds from a distance of 60 cm using a 2 kW metal halide lamp.
27 in Konica 23rd edition developer 5DN-21 (manufactured by Konica ■)
℃ for 20 seconds, and then developed by rubbing lightly with a degreased wire.

The obtained planographic printing plate after development was transferred to Heidelberg GTO
When printed with a printing machine, both Example 1 and Comparative Example 1,
The non-printed areas of the paper were not stained at all.

Next, the coated sample was forcibly stored at a temperature of 55° C., and then exposed, developed, and printed in the same manner as described above.

In the sample of Comparative Example 1, stains appeared on the entire surface of the printed matter after 3 days of forced storage, but in the sample of Example 1, no stains occurred at all even after 5 days of forced storage.

Examples 2 to 23 and Comparative Examples 2 to 3 In the photosensitive liquid of composition (1), the radical scavenger was added as shown in Table-1.
The same evaluation as above was performed by changing the diazo resin 11 and the polymer compound (11 to those shown in Table 1).

The staining of the printed matter was evaluated using the following three levels.

○: The non-image area is not stained at all.

62 Partial staining occurs.

×: The entire paper surface becomes dirty.

The results are shown in Table 1. As is clear from Table 1, the printed matter obtained with the photosensitive lithographic printing plate according to the example of the present invention had good results, and the developability after storage was It can be seen that the storage stability is good. That is, in Examples 1 to 6 and 18 to 23, the non-image areas were not stained at all even after forced storage for 3 days and 5 days, as in the case of unstored materials, and they gave extremely excellent results. In Examples 15 to 17, stains were only partially generated after 5 days of forced storage, and in Examples 7 to 14, stains were only partially generated after 3 days and 5 days of forced storage. On the other hand, Comparative Examples 1 to 3
Although there was no stain in the unstored state, stains appeared on the entire surface of the paper after 3 days of forced storage, and the same was true even after 5 days, indicating poor storage developability.

,−・“.

〔Effect of the invention〕

As described above, the photosensitive lithographic printing plate of the present invention has excellent storage stability, especially storage developability, and has the effect of not causing stains even when used for printing after storage.

Claims (1)

[Scope of Claims] 1. A photosensitive composition comprising a diazo resin, an alkali-soluble/swellable polymer compound, and a radical scavenger. 2. A photosensitive lithographic printing plate having a diazo resin, an alkali-soluble/swellable polymer compound, and a radical scavenger on a support.