JPH08160615A - Photo-polymerizable composition, photosensitive lithographic plate, and developing method thereof - Google Patents

Abstract

PURPOSE: To provide a photo-polymerization composition and a photosensitive lithographic plate reducing the fluctuation of sensitivity under the existence of oxygen without providing an oxygen shielding layer in particular and causing no stickiness and no blocking on the surface when a photosensitive layer is formed. CONSTITUTION: This photo-polymerizable composition contains a polymerizable compound having addition polymerization unsaturated bond, a photo-polymerization initiator, and an alkali-soluble polymer compound. The polymerizable compound having addition polymerization unsaturated bond is a compound expressed by the formula, where R<1> , R<2> , R<3> indicate the substituent having addition polymerization unsaturated bond.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photopolymerizable composition and a photosensitive lithographic printing plate which can be used in a photosensitive lithographic printing plate.

[0002]

2. Description of the Related Art A photopolymerizable composition obtained by mixing a photopolymerization initiator with a polymerizable compound having an addition-polymerizable unsaturated group (photopolymerizable monomer) is photopolymerized by irradiation with actinic rays such as ultraviolet rays. Become a polymer. Utilizing changes in physical properties such as solubility and adhesiveness accompanying changes to this polymer,
It is used as a light-sensitive material for forming images.

When an image is formed using a light-sensitive material using these photopolymerizable compositions, the radical polymerization reaction in the photopolymerizable compositions is inhibited in the presence of oxygen, resulting in a decrease in sensitivity and a fluctuation in sensitivity due to fluctuations in oxygen concentration. Since a transparent film called a cover sheet is attached to the surface of the photosensitive material, or a transparent polymer layer called an overcoat is applied to the photosensitive material to prevent oxygen from contacting the photosensitive layer. That was generally done.

However, the method of attaching the cover sheet to the surface of the photosensitive material to prevent oxygen from coming into contact with the photosensitive layer requires an extra step of attaching the cover sheet to the surface of the photosensitive layer in manufacturing the photosensitive material. Also, when using the obtained light-sensitive material, light scattering occurs at the interface between the cover sheet and the light-sensitive layer at the time of exposure, leading to deterioration of image quality, and peeling off the cover sheet before development. This is not a preferable method because it takes time and effort.

A method of coating an overcoat layer on the surface of a photosensitive material to prevent oxygen from coming into contact with the photosensitive layer is disclosed in a solvent which does not dissolve the photosensitive layer, is transparent and has a low oxygen permeability, and a developing solution. It is carried out by dissolving a polymer soluble in water, coating on the photosensitive layer and drying. Generally, the above polymer is polyvinyl alcohol (PVA).
Is used. This method also has a problem in that, in manufacturing a light-sensitive material, equipment for performing multi-layer coating is required, and the overcoat coating liquid permeates into the photosensitive layer at the time of coating to deteriorate the performance of the photosensitive layer.

Further, since the photopolymerizable composition usually contains a large amount of a photopolymerizable monomer which is a liquid, it will be sticky or sticky unless an overcoat layer or a cover film is provided on the surface of the photosensitive lithographic printing plate. There is also a problem that blocking occurs when stored repeatedly.

[0007]

Accordingly, the first object of the present invention is to reduce the fluctuation of sensitivity even in the presence of oxygen without providing an oxygen barrier layer, and to reduce the surface area of the photosensitive layer when it is formed. It is to provide a photopolymerizable composition that does not cause stickiness or blocking.

A second object of the present invention is that the sensitivity does not fluctuate even in the presence of oxygen, without providing an oxygen barrier layer.
Another object of the present invention is to provide a photosensitive lithographic printing plate that does not cause stickiness or blocking on the surface without providing an overcoat layer or a cover film.

A third object of the present invention is to provide a photosensitive lithographic printing plate which can be developed with a developer containing substantially no organic solvent, and a method for developing with a developer containing substantially no organic solvent. To do.

[0010]

The above objects of the present invention are: (1) A photopolymerizable composition containing a polymerizable compound having an addition polymerizable unsaturated bond, a photopolymerization initiator and an alkali-soluble polymer compound. In the above, the photopolymerizable composition, wherein the polymerizable compound having an addition polymerizable unsaturated bond is a compound represented by the following general formula [I].

[0011]

Embedded image [In the formula, R ¹ , R ² and R ³ represent a substituent having an addition-polymerizable unsaturated bond. (2) The photopolymerizable composition as described in (1) above, which further contains a diazo compound. (3) The polymerizable compound having an addition-polymerizable unsaturated bond is a compound selected from tris (acryloxyethyl) isocyanurate and tris (methacryloxyethyl) isocyanurate, (1) above Alternatively, the photopolymerizable composition according to (2). (4) The photopolymerizable composition as described in (1) to (3) above, wherein the alkali-soluble polymer compound is a polymer compound having a phenolic hydroxyl group in the molecule. (5) On a support having a hydrophilic surface, the above (1) to
(4) A photosensitive lithographic printing plate comprising a layer of the photopolymerizable composition described in (4). (6) A method for developing a photosensitive lithographic printing plate, which comprises developing the photosensitive lithographic printing plate described in (5) above with a developer containing substantially no organic solvent. Achieved by

The present invention will be described in detail below.

First, the compound represented by the following general formula [I] (hereinafter referred to as the compound of general formula [I]) will be explained.

[0014]

Embedded image [In the formula, R ¹ , R ² and R ³ represent a substituent having an addition-polymerizable unsaturated bond. In the general formula [I], the substituent having an addition polymerizable unsaturated bond represented by R ¹ , R ² and R ³ is a substituent having an addition polymerizable unsaturated bond which undergoes addition polymerization by light. ,
Although not particularly limited, for example, an acryloxyethyl group,
Methacryloxyethyl group,

[0015]

[Chemical 4] Can be mentioned.

Specific examples of the compound of the general formula [I] used in the present invention include the followings.

[0017]

Embedded image The compound of the general formula [I] may be used alone, or
Two or more compounds of general formula [I] may be used in combination.

In the present invention, all the polymerizable compounds having an addition-polymerizable unsaturated bond may be compounds of the general formula [I], or some of them may be compounds of the general formula [I]. It may be. In addition, another polymerizable compound having an addition polymerizable unsaturated bond may be used in combination.

These polymerizable compounds having an addition-polymerizable unsaturated bond that can be used in combination are known and may have any chemical structure, but two or more addition-polymerizable unsaturated compounds in the molecule may be used. Compounds having a saturated bond are preferred.

Examples of the polymerizable compound having an addition-polymerizable unsaturated bond that can be used in combination include, for example, unsaturated carboxylic acids, esters of unsaturated carboxylic acids with aliphatic polyhydroxy compounds, and unsaturated carboxylic acids with aromatic polyhydroxy compounds. Esters with hydroxy compounds, unsaturated carboxylic acids and polyvalent carboxylic acids and the aforementioned aliphatic polyhydroxy compounds, esters obtained by the esterification reaction with polyvalent hydroxy compounds such as aromatic polyhydroxy compounds, and the like.
Specifically, diethylene glycol di (meth) acrylate described in JP-A-59-71048,
Triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol triacrylate, hydroquinone di (meth) acrylate, pyrogallol triacrylate,
2,2-bis (4-acryloxydiethoxyphenyl)
Propane etc. are mentioned. In addition, (meth) acrylamides such as ethylenebis (meth) acrylamide, hexamethylenebis (meth) acrylamide, or
A vinyl urethane compound, an epoxy (meth) acrylate, etc. can be mentioned.

In the present invention, the amount of the polymerizable compound having an addition polymerizable unsaturated bond used is usually 5 to 70% by weight, preferably 10 to 70% by weight based on the total solid content of the photopolymerizable composition. It is 50% by weight.

The proportion of the compound of the general formula [I] in the polymerizable compound having an addition-polymerizable unsaturated bond is preferably 20 to 100% by weight.

The photopolymerization initiator that can be used in the present invention is not particularly limited, and conventionally known ones used in photopolymerizable compositions can be used. Examples thereof include benzoin, benzoin alkyl ether, benzophenone, anthraquinone,
Any of Michler's ketone, trihalomethyl-s-triazine compounds, oxadiazole compounds, biimidazole-Michler's ketone complex system, thioxanthone compound and aromatic tertiary amine complex system, etc. can be preferably used.

As the photopolymerization initiator, a compound having absorption at the wavelength of the light source used for exposing the photosensitive lithographic printing plate is usually used.

The amount of the photopolymerization initiator used is usually 0.5 to 30% by weight, more preferably 2 to 15% by weight, based on the total solid content of the photopolymerizable composition.

The alkali-soluble polymer compound that can be used in the present invention is not particularly limited, and conventionally known alkali-soluble polymer compounds used in photopolymerizable compositions can be used, and polymers having any chemical structure can be used. Even compounds can be used. Further, two or more of these alkali-soluble polymer compounds may be used in combination.

The preferred alkali-soluble polymer compound is
(1) Unsaturated carboxylic acids such as methacrylic acid, which are copolymers of vinyl-based monomers,
(2) Unsaturated carboxylic acid esters such as methyl methacrylate, and (3) phenolic hydroxyl group-containing monomers such as hydroxyphenyl methacrylamide and the like.

It is necessary to use, as the constituent monomer of these copolymers, a monomer that makes the polymer compound soluble in alkali.

In the present invention, the term "alkali-soluble" refers not only to those soluble in alkaline water but also those having swellability in alkaline water.

In the present invention, the alkali-soluble polymer compound preferably used is a vinyl monomer having an aromatic hydroxyl group in its side chain, specifically o, m, p-hydroxyphenyl (meth) acrylamide, o. , M, p-
Obtained by copolymerizing hydroxystyrene, o, m, p-hydroxyphenyl (meth) acrylate, o, m, p-hydroxyphenylmaleimide and the like with vinyl monomers shown in (a) to (k) below. Examples thereof include vinyl copolymers having an aromatic hydroxyl group in the side chain. (A) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, (b) acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, etc. α, β-unsaturated carboxylic acid,
(C) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, acrylic acid-
(Substituted) alkyl acrylates such as 2-chloroethyl, glycidyl acrylate and N-dimethylaminoethyl acrylate, (d) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate. , (Substituted) alkyl methacrylates such as N-dimethylaminoethyl methacrylate,
(E) Acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N- Acrylamides or methacrylamides such as nitrophenyl acrylamide and N-ethyl-N-phenyl acrylamide, (f) ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether and other vinyl ethers. (G) vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate, etc. Glycol ester compounds, (h) styrene,
Styrenes such as α-methylstyrene, methylstyrene and chloromethylstyrene, (i) vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone, (j) ethylene, propylene, isobutylene, butadiene, It is also possible to copolymerize olefins such as isoprene, (k) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, and other monomers copolymerizable with the above monomers.

From the standpoint of developability, the vinyl copolymer preferably contains the unsaturated carboxylic acid mentioned in (b) above, has a preferable acid value of 100 or less, and has a preferable molecular weight. It is 10,000 to 130,000.

The vinyl copolymer used in the present invention is contained in the solid content of the photosensitive composition in an amount of usually 30 to 99% by weight, preferably 40 to 95% by weight.

Various additives other than the above may be added to the photopolymerizable composition of the present invention.

Addition of a diazo compound to the photopolymerizable composition of the present invention is preferable because it improves the adhesion to the support and reduces the polymerization inhibition caused by the presence of oxygen.

Examples of the diazo compound that can be used in the present invention include condensation resins of aromatic diazonium compounds and carbonyl compounds and salts of these condensation resins. These condensation resins have COO in their molecule.
Those into which a substituent imparting alkali solubility such as H, OH and SO ₃ H is introduced are preferable.

The diazo resin preferably used in the present invention is a co-condensation compound containing an aromatic compound having at least one member selected from the group consisting of a carboxyl group and a hydroxyl group and an aromatic diazonium compound as constituent units in the molecule.

The aromatic compound having at least one member selected from the group consisting of a carboxyl group and a hydroxyl group has an aromatic ring substituted with at least one carboxyl group and / or an aromatic ring substituted with at least one hydroxyl group. It is contained in the molecule, and in this case, the carboxyl group and the hydroxyl group may be substituted with the same aromatic ring.

The above aromatic ring is preferably an aryl group such as a phenyl group or a naphthyl group.

The above-mentioned carboxyl group or hydroxyl group may be directly bonded to the aromatic ring, or may be bonded via some bonding group (hereinafter, simply referred to as joint).

In the above case, 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 preferably 1 to 3. Furthermore, examples of the joint include an alkylene group having 1 to 4 carbon atoms.

Specific examples of the above-mentioned aromatic compound containing a carboxyl group and / or a hydroxyl group include benzoic acid, (o, m, 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-methoxybenzoyl) benzoic acid, 4- (p-methylanilino)
Benzoic acid, 4-phenylsulfonylbenzoic acid, phenol, (o, m, p) -cresol, xylenol, resorcin, 2-methylresorcin, (o, m, p) -methoxyphenol, m-ethoxyphenol, catechol, fluoro Glycine, p-hydroxyethylphenol, naphthol, pyrogallol, hydroquinone, p-hydroxybenzyl alcohol, 4-chlororesorcin,
Biphenyl 4,4'-diol, 1,2,4-benzenetriol, bisphenol A, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, p-hydroxyacetophenone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylamine, 4,4'-dihydroxydiphenylsulfide cumylphenol, (o, m, p) -chlorophenol, (o, m, p) -bromophenol, salicylic acid, 4-methylsalicylic acid, 6 -Methylsalicylic acid, 4-ethylsalicylic acid, 6-propylsalicylic acid,
6-lauryl salicylic acid, 6-stearyl salicylic 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-dihydroxy benzoic acid,
2,4-dihydroxy-6-methylbenzoic acid, 2,6-
Dihydroxybenzoic acid, 2,6-dihydroxy-4-methylbenzoic acid, 4-chloro-2,6-dihydroxybenzoic acid, 4-methoxy-2,6-dioxybenzoic acid, gallic acid, phloroglucincarboxylic acid, 2 , 4,5-Trihydroxybenzoic acid, m-galloyl gallic acid, tannic acid, m-benzoyl gallic acid, m- (p-toluyl) gallic acid, protocatechuyl gallic acid, 4,6-dihydroxyphthalic acid, (2,4-dihydroxyphenyl)
Acetic acid, (2,4-dihydroxyphenyl) acetic acid, (3,
4,5-trihydroxyphenyl) acetic acid, p-hydroxymethylbenzoic acid, p-hydroxyethylbenzoic acid, 4
-(P-hydroxyphenyl) methylbenzoic acid, 4-
(O-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-hydroxyphenyl) Examples thereof include sulfonyl) benzoic acid and 4- (p-hydroxyphenylthio) benzoic acid. Of these, salicylic acid, p-hydroxybenzoic acid, p-methoxybenzoic acid, and metachlorobenzoic acid are particularly preferable.

The aromatic diazonium compound forming the constitutional unit of the above-mentioned co-condensed diazo resin includes, for example, Japanese Patent Publication No.
Although diazonium salts such as those listed in Japanese Patent No. 48001 can be used, in particular, diphenylamine-
4-diazonium salts are preferred.

The diphenylamine-4-diazonium salts are derived from 4-amino-diphenylamines, and such 4-amino-diphenylamines include 4-amino-diphenylamine and 4-amino-3-.
Methoxy-diphenylamine, 4-amino-2-methoxy-diphenylamine, 4-amino-2'-methoxy-
Diphenylamine, 4-amino-4'-methoxy-diphenylamine, 4-amino-3-methyl-diphenylamine, 4-amino-3-ethoxy-diphenylamine,
4-amino-3-β-hydroxy-ethoxydiphenylamine, 4-amino-diphenylamine-2-sulfonic acid, 4-amino-diphenylamine-2-carboxylic acid,
4-amino-diphenylamine-2'-carboxylic acid and the like can be mentioned, and 4-amino-4'-methoxy-diphenylamine and 4-amino-diphenylamine are particularly preferable.

The co-condensed diazo resin can be obtained by a known method, for example, Photographic Science and Engineering (Photo.Sci.Eng.) Vol. 17, page 33 (1973), US Pat. No. 2,063, No. 631, No. 2,679,498, and a diazonium salt, an aromatic compound having a carboxyl group and / or a hydroxyl group, and an aldehyde such as para. It can be obtained by polycondensing formaldehyde, acetaldehyde, benzaldehyde or ketones such as acetone and acetophenone.

The aromatic compound having a carboxyl group and / or a hydroxyl group in the molecule, the aromatic diazo compound and the aldehydes or ketones can be freely combined with each other, and two or more kinds of them can be mixed and co-condensed. It is also possible to do so.

The molar ratio of the aromatic compound having at least one of the carboxyl group and the hydroxyl group to the aromatic diazo compound is usually 1: 0.1 to 0.1:
1, preferably 1: 0.5 to 0.2: 1, more preferably 1: 1 to 0.2: 1. In this case, the total molar ratio of aromatic compounds and aromatic diazo compounds having at least one of a carboxyl group and a hydroxyl group and aldehydes or ketones is usually 1: 0.6.
To 1.5, preferably 1: 0.7 to 1.2, and the reaction is carried out at a low temperature for a short time, for example, for about 3 hours to obtain a co-condensed diazo resin.

The counter anion of the diazo resin used in the present invention includes an anion that forms a salt with the diazo resin in a stable manner and makes the resin soluble in an organic solvent. These include organic carboxylic acids such as decanoic acid and benzoic acid, organic phosphoric acids such as phenylphosphoric acid and sulfonic acids, and typical examples are methanesulfonic acid, chloroethanesulfonic acid, dodecanesulfonic acid, benzenesulfonic acid. ,
Aliphatic and aromatic sulfonic acids such as toluene sulfonic acid, mesitylene sulfonic acid, anthraquinone sulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 4-acetylbenzene sulfonic acid and dimethyl-5-sulfoisophthalate , 2, 2 ', 4,
4'-tetrahydroxybenzophenone, 1,2,3-
Hydroxyl-containing aromatic compounds such as trihydroxybenzophenone and 2,2 ', 4-trihydroxybenzophenone;
Examples thereof include halogenated Lewis acids such as hexafluorophosphoric acid and tetrafluoroboric acid, perhalogen acids such as ClO ₄ and IO _{4, and the} like, but are not limited thereto. Among these, particularly preferable are hexafluorophosphoric acid,
Tetrafluoroboric acid and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid.

The molecular weight of the above co-condensed diazo resin can be obtained as an arbitrary value by variously changing the molar ratio of each monomer and the condensation conditions, but it is effectively used for the intended purpose of the present invention. To have a molecular weight of about 400-1
It is generally selected from the range of 10,000, but preferably about 800 to 5,000.

The diazo compound is added to the photopolymerizable composition in an amount of 1
It is preferable that the content is ˜12% by weight.

A dye may be further used in the photopolymerizable composition of the present invention. The dye is used for the purpose of obtaining a visible image by exposure (exposed visible image) and a visible image after development.

As the dye, those which change color tone by reacting with free radicals or acids can be preferably used.
Here, "the color tone changes" includes any of a change from colorless to a colored tone, a change from a colored to a colorless or a different colored tone. Preferred dyes are those which form a salt with an acid to change the color tone.

Examples of dyes that change from colored to colorless or to different colored tones include Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) and Oil Blue #.
603 [manufactured by Orient Chemical Industry Co., Ltd.], patent pure blue [manufactured by Sumitomo Sangoku Chemical Co., Ltd.], crystal violet,
Brilliant Green, Ethyl Violet, Methyl Violet, Methyl Green, Erythrosin B, Basic Fuchsin, Malachite Green, Oil Red, m
-Cresol purple, rhodamine B, auramine, 4
Examples thereof include triphenylmethane dyes, diphenylmethane dyes, oxazine dyes, xanthene dyes, iminonaphthoquinone dyes, azomethine dyes, and anthraquinone dyes represented by -p-diethylaminophenyliminonaphthoquinone and cyano-p-diethylaminophenylacetanilide.

On the other hand, examples of dyes that change from colorless to colored include, for example, leuco dyes and triphenylamine, diphenylamine, o-chloroaniline,
1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p'-bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p, p ', p "-tris-dimethylaminotriphenylmethane, p, p'-bis-dimethylaminodiphenylmethylimine, p, p ', p "-triamino-o-
Methyltriphenylmethane, p, p′-bis-dimethylaminodiphenyl-4-anilinonaphthylmethane, p,
Examples thereof include primary or secondary arylamine dyes represented by p ′, p ″ -triaminotriphenylmethane.

Of these dyes, triphenylmethane type dyes and diphenylmethane type dyes are preferable, triphenylmethane type dyes are more preferable, and Victoria Pure Blue BOH is particularly preferable.

The above dye is usually contained in the photopolymerizable composition in an amount of 0.5 to 10% by weight based on the total solid content, and preferably about 1 to 1.
5 wt% is included.

Various additives can be further added to the photopolymerizable composition of the present invention.

For example, alkyl ethers (eg, ethyl cellulose, methyl cellulose) for improving coating properties, fluorochemical surfactants and nonionic surfactants (eg, Pluronic L-64 (Asahi Denka Co., Ltd.)
A), a plasticizer for imparting flexibility and abrasion resistance to the coating film (for example, butylphthalyl, 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), an oil sensitizer for improving the oil sensitivity of the image area (for example, JP-A-55) -527-styrene-maleic anhydride copolymer alcohol-based half-esterified products), stabilizers [eg phosphoric acid, phosphorous acid, organic acids (citric acid, oxalic acid, benzenesulfonic acid, naphthalenesulfone) Acid, 4-methoxy-2-hydroxybenzophenone-5-sulfonic acid, tartaric acid, etc.), a development accelerator (eg, higher alcohol, acid anhydride, etc.) and the like.
The addition amount of these additives varies depending on the intended purpose, but generally with respect to the total solid content of the photopolymerizable composition,
It is 0.01 to 30% by weight.

The photosensitive lithographic printing plate of the present invention is prepared by using the photopolymerizable composition of the present invention in a suitable solvent (methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, acetone,
Methyl ethyl ketone, methanol, dimethylformamide, dimethylsulfoxide, water or mixtures thereof)
It can be obtained by dissolving it in a solution to prepare a coating solution of the photopolymerizable composition, coating it on a support, and drying it to form a photosensitive layer.

The concentration of the photopolymerizable composition in the coating solution is 1
It is desirable to be in the range of 50 wt%.

For coating, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating and curtain coating can be used.

In this case, the coating amount of the photopolymerizable composition may be about 0.2 to 10 g / m ² in dry weight.

An overcoat layer can be provided on the photosensitive lithographic printing plate of the present invention. The overcoat layer can be formed by applying an aqueous solution of a water-soluble polymer on the photosensitive layer and drying. When providing the overcoat layer, more preferable results can be obtained by using a polymer having an excellent oxygen barrier property such as polyvinyl alcohol and acidic celluloses.

As the support, paper, plastic (eg, polyethylene, polypropylene, polystyrene, etc.) laminated paper, aluminum (including aluminum alloy), metal plate such as zinc, copper, cellulose diacetate, cellulose triacetate, etc. , Films of plastics such as cellulose propionate, polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, polyvinyl acetal, etc., paper or plastic films laminated or vapor-deposited with the above metals, steel plates plated with aluminum or chrome, etc. Of these, aluminum and aluminum-coated composite supports are particularly preferred.

Further, it is desirable that the surface of the aluminum material is roughened for the purpose of enhancing water retention and improving adhesion to the photosensitive layer.

Examples of the surface roughening method include generally known brush polishing method, ball polishing method, electrolytic etching, chemical etching, liquid honing, sand blasting and the like and combinations thereof, preferably brush polishing method,
Electrolytic etching, chemical etching and liquid honing are mentioned, of which the roughening method involving the use of electrolytic etching is particularly preferred. Further, as the electrolytic bath used in the electrolytic etching, an aqueous solution containing an acid, an alkali or a salt thereof or an aqueous solution containing an organic solvent is used, and among these, an electrolytic solution containing hydrochloric acid, nitric acid or a salt thereof is particularly used. Liquids are preferred. Further, the surface-roughened aluminum plate is desmutted with an acid or alkali aqueous solution, if necessary. The aluminum plate thus obtained is preferably anodized, and particularly preferably, a method of treating with a bath containing sulfuric acid or phosphoric acid can be mentioned. Further, if necessary, surface treatment such as treatment with an alkali silicate or hot water, or immersion in a water-soluble polymer compound or an aqueous solution of potassium fluorozirconate can be performed.

Conventional conventional methods are applied to the development processing of the photosensitive lithographic printing plate of the present invention. That is, a negative relief image is obtained with respect to the original image by exposing through a transparent original image having a line image, a halftone image and the like and then developing with an aqueous developing solution. Examples of the active light source suitable for exposure include a carbon arc lamp, a mercury lamp, a xenon lamp, a metal halide lamp, and a strobe.

The developing solution is not particularly limited, but particularly preferred is an alkaline aqueous solution containing substantially no organic solvent.

The term "substantially free of organic solvent" means that the organic solvent is not contained to the extent that it causes problems in hygiene and safety, and that it does not contain any organic solvent. is not. Generally, when the organic solvent contained in the developer composition is 1% by weight or less, these problems do not occur.

From the viewpoint of hygiene and safety, the content of the organic solvent contained in the developer composition is preferably small, and the content of the organic solvent is 0.5% by weight or less, more preferably the organic solvent content. That is, no amount is contained.

Preferred alkaline agents used in the developing solution include, for example, potassium silicate, lithium silicate, sodium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium triphosphate, and sodium diphosphate. Examples include potassium triphosphate, dibasic potassium phosphate, sodium carbonate, potassium carbonate and the like. Among these, a developer containing an alkali silicate such as potassium silicate, lithium silicate, or sodium silicate has the best development gradation and is most preferable.

In the present invention, the concentration of SiO ₂ in the developing solution is preferably 0.8 to 8% by weight.

The pH (25 ° C.) of the developing solution is preferably 12 or more, more preferably 12.5 to 14. Further, water-soluble sulfites such as sodium sulfite, potassium sulfite, lithium sulfite, and magnesium sulfite can be added to the developer. The preferred content of sulfite in the developer composition is 0.
The amount is 05 to 4% by weight, and more preferably 0.1 to 1% by weight.

Further, in a developing solution, Japanese Patent Laid-Open No. 50132/1975
Anionic surfactants, amphoteric surfactants such as those described in JP-A No. 4-75255,
By containing at least one of the nonionic surfactants described in JP-A-60-111246, it is also described in JP-A-55-95946 and JP-A-56-142528. By including the polymer electrolyte as described above, the wettability to the photosensitive layer can be enhanced and the gradation can be further enhanced.
The amount of such a surfactant added is not particularly limited, but is 0.0
It is preferably from 03 to 3% by weight, particularly from 0.006 to 1% by weight
Is preferred.

Further, it is preferable to use an alkali silicate containing 20 mol% or more of all alkali metals in the developer because the generation of insolubles in the developer is reduced, and more preferably 90 mol% or more of potassium is used. Is that
Most preferably, potassium is 100 mol%.

Further, the developer used in the present invention may contain an antifoaming agent. Suitable defoamers include organosilane compounds.

The photosensitive lithographic printing plate of the present invention can be further provided with an overcoat layer. The overcoat layer can be formed by applying an aqueous solution of a water-soluble polymer on the photosensitive layer and drying.

In the present invention, by using the compound of the general formula [I], the influence of oxygen on the inhibition of polymerization is reduced, and the fluctuation of the sensitivity is reduced even in the presence of oxygen, particularly without providing an oxygen blocking layer. I don't understand the reason.

In the photosensitive lithographic printing plate of the present invention, stickiness and blocking on the surface can be prevented because the compound of the general formula [I] is solid at room temperature.
This is probably because the monomer does not exude from the photosensitive layer even after long-term storage.

Most of the photopolymerizable monomers and oligomers used in ordinary photopolymerizable compositions are liquid at room temperature, and they exude from the photosensitive layer after long-term storage.
It is possible to use photopolymerizable monomers and oligomers that are solid at room temperature in order to prevent seepage from the photosensitive layer.
Since photopolymerizable monomers and oligomers that are solid at room temperature have a very high molecular weight, they have low solubility in a developing solution which is an ordinary alkaline aqueous solution, and these compounds cannot be used for image formation. On the other hand, since the compound having the structure represented by the general formula [I] of the present invention has a low molecular weight, it has high solubility in a developing solution and can easily form an image.

[0080]

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

Example 1 The alkali-soluble acrylic copolymer and diazo resin used in this example were synthesized as follows. <Synthesis of Alkali-Soluble Acrylic Copolymer> Acetone 12 was placed in a 500 ml four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, a heater, and a nitrogen gas inlet tube.
A mixed solvent of 5 ml and 125 ml of methanol was added, and ethyl acrylate 9.0 was used as a monomer.
g (0.09 mol), ethyl methacrylate 34.2 g
(0.30 mol), acrylonitrile 15.9 g (0.
30 mol), methacrylic acid 0.86 g (0.01 mol)
And 4-hydroxyphenylmethacrylamide 51.6
g (0.30 mol) was dissolved. Further, 3.28 g (0.02 mol) of azobisisobutyronitrile was dissolved as a polymerization initiator, heated under a nitrogen stream with strong stirring, and refluxed at about 60 ° C. for 6 hours.

After completion of the reaction, the reaction solution was cooled to room temperature and then poured into water to precipitate a polymer compound. This was collected by filtration and vacuum dried at 50 ° C. for 24 hours to obtain 100 g of an alkali-soluble acrylic copolymer. The yield based on the total amount of monomers was 90%.

The weight average molecular weight of the obtained alkali-soluble acrylic copolymer was measured by gel permeation chromatography (GPC) with pullulan standard and N, N-dimethylformamide (DMF) solvent.
It was 000.

<Synthesis of diazo resin> Water-cooled concentrated sulfuric acid 20
0 g, p-hydroxybenzoic acid 12.7 g (0.09
2 mol) and 4-diazodiphenylamine sulfate 40.5
g (0.138 mol) is dissolved with stirring, taking care that the liquid temperature does not exceed 5 ° C.

Then, 6.22 g of paraformaldehyde
(0.207 mol) was slowly added over 1 hour with stirring to carry out a condensation reaction. Also in this case, care was taken so that the reaction liquid did not exceed 5 ° C. After the addition of paraformaldehyde was completed, stirring was continued at 5 ° C or lower for 30 minutes.

After completion of the reaction, the reaction solution was slowly added to 1600 ml of ethanol cooled to 0 ° C. to form a precipitate. At this time, care was taken so that the liquid temperature did not exceed 40 ° C. The precipitate is filtered by suction filtration and ethanol 3
It was washed with 00 ml to obtain a reaction intermediate a (diazo resin sulfate).

The reaction intermediate a thus taken out was dissolved in 240 ml of water, and 19.04 g (0.14 mol) of zinc chloride dissolved in 90 ml of water was added, whereby a precipitate was formed again. The precipitate was collected by suction filtration to obtain a reaction intermediate b (diazo resin zinc chloride double salt).

The reaction intermediate b taken out was dissolved in 1000 ml of water and then 24.8 g (0.15) of ammonium hexafluorophosphate dissolved in 180 ml of water.
Mol) is added, a precipitate forms.

The precipitate was collected by suction filtration and washed with ethanol 3
After washing with 00 ml, it was dried at 30 ° C. for 3 days to obtain 32.4 g of diazo resin.

<Preparation of Support> An aluminum plate (material 1050, temper H16) having a thickness of 0.30 mm was degreased at 65 ° C. for 1 minute in a 5 wt% caustic soda aqueous solution.
It was washed with water and subjected to electrolytic etching treatment for 30 seconds in a 0.5 molar aqueous hydrochloric acid solution at 25 ° C. and a current density of 60 A / dm ² . Then, in a 5 wt% caustic soda aqueous solution at 60 ° C.,
After performing desmutting treatment for 10 seconds, anodizing treatment was performed for 1 minute in a 20 wt% sulfuric acid aqueous solution at a temperature of 20 ° C. and a current density of 3 A / dm ² . Wash further with water, then 8
A support was prepared by sealing with a 2.5% aqueous solution of sodium silicate at 0 ° C. for 20 seconds and washing with water.

<Preparation of Sample> On this support, a photosensitive solution having the composition shown in Table 1 was coated so that the dry weight was 1.6 g / m ^2, and the mixture was dried in an air stream at 80 ° C. for 2 minutes. After drying, photosensitive lithographic printing plate samples 1 to 4 were prepared.

[0092]

[Table 1]

<< Evaluation of Photosensitive Lithographic Printing Plate Sample >> A step tablet manufactured by Eastman Kodak Co. (a material having a transmission density difference of 0.15 per step) and a negative image film original are added to the obtained photosensitive lithographic printing plate sample. By stacking and using a PS plate baking machine, the glass plate of the PS plate baking machine and the photosensitive lithographic printing plate are brought into close contact with each other by applying a vacuum, and by simply press-bonding without applying a vacuum, a 2 kW metal halide It was exposed for 30 seconds at 8 mW / сm ² using a lamp.

As the sample after exposure, a developer having the following composition was used.
Development was performed at 25 ° C. for 30 seconds. <Developer Composition> A potassium silicate (manufactured by Nippon Kagaku) 1160 g caustic potassium 133 g pure water 5133 g (pH = 12.7) On the developed sample, the solid step value of the step tablet was read to evaluate the sensitivity.

Next, printing was carried out using a Heidelberg GTO printing machine, printing was continued until defective solidification appeared on the solid portion of the printed material, and the printing durability was evaluated by determining the number of printed sheets at that time.

Further, after the coating, three samples were laminated so that the photosensitive layer was in contact with the back surface of the other photosensitive lithographic printing plate, and the sample was stored in the dark at 40 ° C. and 80% RH for 10 days. The stacked samples were peeled off, and blocking of the photosensitive layer and the back surface of the stacked photosensitive lithographic printing plates was evaluated according to the following evaluation criteria. The results are also shown in Table 2.

<Evaluation Criteria for Blocking after Storage> ○: No blocking is observed at all Δ: Partial blocking occurs only at the peripheral portion ×: Blocking occurs on the entire surface

[0098]

[Table 2]

[0099]

INDUSTRIAL APPLICABILITY The photopolymerizable composition and the photosensitive lithographic printing plate of the present invention are less likely to inhibit polymerization by oxygen, the sensitivity fluctuation due to the difference in oxygen concentration is reduced, and the surface of the photosensitive layer is not sticky or blocking. It can be developed with a developer that does not contain an organic solvent that causes pollution, and has excellent printing durability.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Noriyuki Kizu, No. 1 Sakura-cho, Hino City, Tokyo Konica Co., Ltd. (72) Masahisa Murata, No. 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Mitsubishi Chemical Corporation Yokohama Research Institute (72) Inventor Naruo Tsuji 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Mitsubishi Chemical Corporation Yokohama Research Institute

Claims (6)

[Claims] 1. A photopolymerizable composition containing a polymerizable compound having an addition polymerizable unsaturated bond, a photopolymerization initiator and an alkali-soluble polymer compound, wherein the polymerizable compound having an addition polymerizable unsaturated bond. Is a compound represented by the following general formula [I]. Embedded image [In the formula, R ¹ , R ² and R ³ represent a substituent having an addition-polymerizable unsaturated bond. ] 2. The photopolymerizable composition according to claim 1, further comprising a diazo compound. 3. The polymerizable compound having an addition-polymerizable unsaturated bond is a compound selected from tris (acryloxyethyl) isocyanurate and tris (methacryloxyethyl) isocyanurate. The photopolymerizable composition according to 1 or 2. 4. The photopolymerizable composition according to claim 1, wherein the alkali-soluble polymer compound is a polymer compound having a phenolic hydroxyl group in the molecule. 5. A photosensitive lithographic printing plate comprising a support having a hydrophilic surface and a layer of the photopolymerizable composition according to claim 1 provided on the support. 6. A method of developing a photosensitive lithographic printing plate, which comprises developing the photosensitive lithographic printing plate according to claim 5 with a developer containing substantially no organic solvent.