JPH08160612A - Photo-polymrimable composition, photosensitive lithographic printing plate, and developing method thereof - Google Patents

Abstract

PURPOSE: To provide a photo-polymerizable composition and a photosensitive lithographic printing plate having no fluctuation of sensitivity under the existence of oxygen without using an oxygen shielding layer in particular and having high sensitivity. 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 alkali-soluble polymer compound contains a side chain having the repetitive structural unit expressed by formula, where R indicates the hydrogen atom or alkyl group or phenyl group having the carbon number of 1-6.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photopolymerizable composition, a photosensitive lithographic printing plate and a developing method thereof.

[0002]

BACKGROUND OF THE INVENTION A photopolymerizable composition obtained by mixing a photopolymerization initiator with a polymerizable compound having an addition polymerizable unsaturated group is photopolymerized by irradiation with actinic rays such as ultraviolet rays to become a polymer. It is used as a light-sensitive material for forming an image by utilizing changes in physical properties such as solubility and adhesiveness associated with the change to the polymer.

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.

[0006]

Accordingly, a first object of the present invention is to provide a photopolymerizable composition having high sensitivity without fluctuation in sensitivity even in the presence of oxygen without using an oxygen barrier layer. To do.

A second object of the present invention is to provide a photosensitive lithographic printing plate using the photopolymerizable composition and a method for developing the photosensitive lithographic printing plate.

[0008]

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

[0009]

Embedded image [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group. (2) The photopolymerizable composition as described in (1) above, which further contains a diazo compound. (3) The photopolymerizable composition according to the above (1) or (2), wherein the alkali-soluble polymer compound is a compound having a phenolic hydroxyl group in the molecule. (4) In a photopolymerizable composition containing a polymerizable compound having an addition polymerizable unsaturated bond, a photopolymerization initiator and an alkali-soluble polymer compound, at least one compound selected from polypropylene glycol and polyethylene glycol is used. A photopolymerizable composition, which is further contained. (5) The photopolymerizable composition as described in (4) above, which further contains a diazo compound. (6) The photopolymerizable composition according to the above (4) or (5), wherein the alkali-soluble polymer compound is a compound having a phenolic hydroxyl group in the molecule. (7) On a support having a hydrophilic surface, the above (1) to
(6) A photosensitive lithographic printing plate having a photosensitive layer obtained by applying the photopolymerizable composition as described in (6). (8) A method for developing a photosensitive lithographic printing plate, which comprises developing the photosensitive lithographic printing plate described in (7) above with a developer containing substantially no organic solvent. Achieved by

Hereinafter, the present invention will be described in detail.

First, in a photopolymerizable composition containing a polymerizable compound having an addition polymerizable unsaturated bond, a photopolymerization initiator and an alkali-soluble polymer compound, the alkali-soluble polymer compound is represented by the above general formula [I]. The photopolymerizable composition which is an alkali-soluble polymer compound having a side chain having a repeating structural unit represented by (hereinafter, referred to as photopolymerizable composition 1 of the invention) will be described.

Polymerizable compounds having an addition polymerizable unsaturated bond used in the photopolymerizable composition are known, and in the photopolymerizable composition 1 of the present invention, these known addition polymerizable unsaturated bonds are added. The compound having a polymerizable structure may be used and may have any chemical structure, but a compound having two or more addition-polymerizable unsaturated bonds in the molecule is preferable. In addition, a polymerizable compound having two or more addition-polymerizable unsaturated bonds may be used in combination.

The polymerizable compound having an addition-polymerizable unsaturated bond used in the photopolymerizable composition 1 of the present invention is, for example, an unsaturated carboxylic acid or an ester of an unsaturated carboxylic acid and an aliphatic polyhydroxy compound. An ester of an unsaturated carboxylic acid and an aromatic polyhydroxy compound,
Examples thereof include esters obtained by esterification reaction of unsaturated carboxylic acids with polyvalent carboxylic acids and the above-mentioned aliphatic polyhydroxy compounds, polyvalent hydroxy compounds such as aromatic polyhydroxy compounds, and the like. Sho 59-
No. 71048, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol triacrylate, hydroquinone di (meth) acrylate, pyrogallol triacrylate, 2 , 2-bis (4-acryloxydiethoxyphenyl) propane and the like.
Other examples include (meth) acrylamides such as ethylene bis (meth) acrylamide and hexamethylene bis (meth) acrylamide, vinyl urethane compounds and epoxy (meth) acrylates.

The amount of the polymerizable compound having an addition polymerizable unsaturated bond used in the photopolymerizable composition 1 of the present invention is
In the total solid content of the photopolymerizable composition, usually 5 to 70% by weight,
Preferably, it is 10 to 50% by weight.

The photopolymerization initiator that can be used in the present invention is not particularly limited, and conventionally known ones used for photopolymerizable compositions can be used. Examples thereof include benzoin, benzoin alkyl ether, benzophenone, anthraquinone, and the like.
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.

Next, an alkali-soluble polymer compound having a side chain having a repeating structural unit represented by the following general formula [I] (hereinafter referred to as an alkali-soluble polymer compound having polyethylene oxide in the side chain of the present invention. ) Will be described.

[0019]

Embedded image [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group. The alkali-soluble polymer compound having polyethylene oxide in the side chain of the present invention may be any polymer compound having a side chain having a repeating structural unit represented by the general formula [I], and specifically, Examples thereof include an alkali-soluble polymer compound obtained by copolymerizing a macromonomer having a polymerizable unsaturated bond at one end of polypropylene glycol or polyethylene glycol and another vinyl-based monomer.

Examples of the other vinyl monomers include (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 and other α, β-unsaturated carboxylic acids, (c) methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate , Octyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate, N
-(Substituted) alkyl acrylates such as dimethylaminoethyl acrylate, (d) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate, etc. (Substituted) alkylmethacrylate, (e) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide, N-
Acrylamide or methacrylamide such as hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-N-phenylacrylamide, (f) ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, Vinyl ethers such as butyl vinyl ether, octyl vinyl ether and phenyl vinyl ether, (g) vinyl acetate, vinyl chloroacetate, vinyl butyrate,
Vinyl esters such as vinyl benzoate, (h) styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene, (i) methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone, etc. Vinyl ketones, (j) olefins such as ethylene, propylene, isobutylene, butadiene and isoprene, (k) N-vinylpyrrolidone, N
-Vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc. (l) vinyl monomer having an aromatic hydroxyl group, specifically, o, m, p-hydroxyphenyl (meth) acrylamide, o, m, p
-Hydroxystyrene, o, m, p-hydroxyphenyl (meth) acrylate, o, m, p-hydroxyphenyl maleimide and the like.

Further, the alkali-soluble polymer compound having polyethylene oxide in the side chain of the present invention may be copolymerized with another monomer copolymerizable with the above monomer.

The alkali-soluble polymer compound having polyethylene oxide in the side chain of the present invention includes the above-mentioned (l)
Vinyl monomer having an aromatic hydroxyl group, particularly,
A polymer compound having a phenolic hydroxyl group in the molecule obtained by copolymerization using a vinyl monomer having a phenolic hydroxyl group is preferable.

The preferred molecular weight of the alkali-soluble polymer compound having polyethylene oxide in the side chain of the present invention is
It is 20,000 to 200,000, more preferably 30,000 to 130,000, and a preferable acid value is 100 or less.

In the side chain having the repeating structural unit represented by the general formula [I], the repeating number of the repeating structural unit represented by the general formula [I] is preferably 2 to 20, and more preferably 3 to. Twelve.

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.

The alkali-soluble polymer compound having polyethylene oxide in the side chain of the present invention may be used in combination with another alkali-soluble polymer compound, or may be blended with another polymer compound.

The amount of the alkali-soluble polymer compound used in the photopolymerizable composition 1 of the present invention is usually preferably 5 to 95% by weight based on the total solid content of the photopolymerizable composition.

Next, in a photopolymerizable composition containing a polymerizable compound having an addition-polymerizable unsaturated bond, a photopolymerization initiator and an alkali-soluble polymer compound, at least one selected from polypropylene glycol and polyethylene glycol. The photopolymerizable composition further containing one compound (hereinafter referred to as the photopolymerizable composition 2 of the invention) will be described.

The polymerizable compound having an addition-polymerizable unsaturated bond and the photopolymerization initiator used in the photopolymerizable composition 2 of the present invention are described above in the description of the photopolymerizable composition 1 of the present invention. The polymerizable compound having the addition-polymerizable unsaturated bond and the photopolymerization initiator are shown.

The amount of the polymerizable compound having an addition polymerizable unsaturated bond used in the photopolymerizable composition 2 of the present invention is
In the total solid content of the photopolymerizable composition, usually 5 to 70% by weight,
It is preferably 10 to 50% by weight, and the amount of the photopolymerization initiator used is usually 0.5 in the total solid content of the photopolymerizable composition.
-30% by weight, more preferably 2-15% by weight.

Examples of the alkali-soluble polymer compound used in the photopolymerizable composition 2 of the present invention include polymer compounds having a phenolic hydroxyl group in the molecule.

The above-mentioned polymer compound having a phenolic hydroxyl group in the molecule is a polymer compound containing a compound having an aromatic hydroxyl group in its side chain as a constituent unit in the molecule and soluble or swellable in alkaline water. These polymer compounds are, for example, vinyl monomers having an aromatic hydroxyl group in the side chain, specifically, o, m, p-hydroxyphenyl (meth) acrylamide, o, m, p-hydroxystyrene. , O, m, p-hydroxyphenyl (meth) acrylate, o, m, p-hydroxyphenylmaleimide, etc. and a vinyl monomer as shown in the following (a) to (k) can be obtained by copolymerization. . (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, The olefins such as isoprene, (k) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, and the like, and the polymer compound having a phenolic hydroxyl group in the molecule include the above monomer. You may copolymerize the other monomer which can be copolymerized with.

From the standpoint of developability, among the above-mentioned polymer compounds having a phenolic hydroxyl group in the molecule, those containing the unsaturated carboxylic acid mentioned as the above (b) as a copolymerization component are preferable. The preferred molecular weight of the polymer compound having a phenolic hydroxyl group in the molecule is 20,000.
˜200,000, more preferably 30,000
It is 0 to 130,000, and the preferable acid value is 100 or less.

The term "alkali-soluble" as used in the present invention means not only those which are soluble in alkaline water but also those which are swellable in alkaline water.

The amount of the alkali-soluble polymer compound used in the photopolymerizable composition 2 of the present invention is usually preferably 5 to 95% by weight based on the total solid content of the photopolymerizable composition.

The polypropylene glycol and polyethylene glycol used in the photopolymerizable composition 2 of the present invention preferably have a molecular weight of 1,000 to 10,000.

In the case of using polypropylene glycol and polyethylene glycol, at least one of polypropylene glycol and polyethylene glycol may be used, and it is usually 0.5 to 1 in the solid content of the photopolymerizable composition.
It is good to contain 0% by weight, preferably 1 to 4% by weight.

The photopolymerizable compositions 1 and 2 of the present invention (hereinafter,
Together, it is called the photopolymerizable composition of the present invention. Addition of a diazo compound in () improves the adhesiveness to the support, and
It is preferable to add a diazo compound to the photopolymerizable composition because the inhibition of polymerization due to oxygen can be reduced.

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 of the group consisting of a carboxyl group and a hydroxyl group described above 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 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 compounds forming the constitutional unit of the above-mentioned co-condensed diazo resin include, 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 above-mentioned 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, for example, in sulfuric acid, phosphoric acid, or hydrochloric acid according to the method described in each specification. It is obtained by polycondensing paraformaldehyde, 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 which 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 the color tone change from colorless to colored, and the color tone change from colored to colorless or a different color. 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 dyes and diphenylmethane dyes are preferable, triphenylmethane dyes are more preferable, and Victoria Pure Blue BOH is particularly preferable.

The above dye is generally contained in the photopolymerizable composition in an amount of 0.5 to 10% by weight, and preferably about 1 to 10% by weight based on the total solids.
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 comprises 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 in a solution to prepare a coating solution of the photopolymerizable composition, coating the solution on a support and drying the solution 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.

The support used for the above-mentioned photosensitive lithographic printing plate is paper, plastic (for example, polyethylene, polypropylene, polystyrene, etc.) laminated paper, aluminum (including aluminum alloy), zinc,
Metal plates such as copper, cellulose diacetate, cellulose triacetate, cellulose propionate, polyethylene terephthalate, plastic films such as polyethylene, polypropylene, polycarbonate, polyvinyl acetal and the like, metals such as those mentioned above are laminated or vapor deposited. Examples thereof include paper or plastic film, and aluminum or chrome-plated steel plates. Of these, aluminum and an aluminum-coated composite support are particularly preferable.

The surface of the aluminum material is preferably surface-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.

The photopolymerizable composition of the present invention does not change the sensitivity in the presence of oxygen and can obtain high sensitivity even without using an oxygen barrier layer. On the layer of the polymerizable composition, for example, a protective layer made of a polymer having an excellent oxygen barrier property such as polyvinyl alcohol, acidic celluloses, etc. is provided to further prevent the polymerization inhibiting action by oxygen in the air. You may

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 can be 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 developer. 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 of the present invention include, for example, potassium silicate, lithium silicate, sodium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, tribasic sodium phosphate, and secondary sodium silicate. Examples thereof include sodium phosphate, 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 the developing solution, Japanese Patent Laid-Open No.
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.

Furthermore, 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.

[0081]

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

The alkali-soluble acrylic copolymers 1 to 5 and the diazo resin used in the examples were synthesized as follows.

<Synthesis of Alkali-Soluble Acrylic Copolymer 1> 125 ml of acetone and 125 ml of methanol were 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 mixture of milliliters was added, and 8.0 g (0.08 mol) of ethyl acrylate, 34.2 g (0.30 mol) of ethyl methacrylate, 15.9 g (0.30 mol) of acrylonitrile, and 0.86 g of methacrylic acid were used as monomers.
(0.01 mol), 51.6 g (0.30 mol) of 4-hydroxyphenylmethacrylamide and polypropylene glycol 500 methacrylate (product name Bremmer P
P500, manufactured by NOF CORPORATION, 6.08 g (0.01 mol) was dissolved. Further, 3.28 g (0.02 mol) of azobisisobutyronitrile was dissolved as a polymerization initiator,
The mixture was heated under strong stirring under a nitrogen stream 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 105 g of alkali-soluble acrylic copolymer 1. The yield based on the total amount of monomers was 90%.

Obtained Alkali-Soluble Acrylic Copolymer 1
Was measured by gel permeation chromatography (GPC) with pullulan standard and N, N-dimethylformamide (DMF) solvent.
It was 8000. <Synthesis of Alkali-Soluble Acrylic Copolymers 2 to 5> Alkali-soluble acrylic copolymer 1 can be used in the same manner as in the synthesis of the above-mentioned alkali-soluble acrylic copolymer 1 except that the molar ratio of the monomers to be copolymerized is changed to the ratio shown in Table 1. Fused acrylic copolymers 2 to 5 were obtained.

[0086]

[Table 1]

<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 then 19.04 g (0.14 mol) of zinc chloride dissolved in 90 ml of water was added to again form a precipitate. 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.

Example 1 <Preparation of Support> A 0.30 mm thick aluminum plate (material 1050, tempered H16) was degreased in a 5 wt% caustic soda aqueous solution at 65 ° C. for 1 minute and then washed with water. ,
25 ℃ in 0.5M hydrochloric acid solution, current density 60A / dm
^The electrolytic etching treatment was performed for 30 seconds under the condition of ² . Then, after desmutting treatment in a 5 wt% caustic soda aqueous solution at 60 ° C. for 10 seconds, anodizing treatment is performed in a 20 wt% sulfuric acid aqueous solution at a temperature of 20 ° C. and a current density of 3 A / dm ² for 1 minute. It was Further, the substrate was washed with water, and subsequently, a pore-sealing treatment was performed with a 2.5% aqueous solution of sodium silicate at 80 ° C. for 20 seconds to wash with water to prepare a support.

<Preparation of photosensitive lithographic printing plate sample 1> On this support, a photosensitive solution having the following composition was dried to a dry weight of 1.
It was coated so as to be 6 g / m ² and dried under an air stream at 80 ° C. for 2 minutes to prepare a photosensitive lithographic printing plate sample 1. Photosensitive solution composition Alkali-soluble acrylic copolymer 1 7.0 g Trimethylolpropane triacrylate 3.0 g 2,4-Diethylthioxanthone 0.5 g Ethyl 4-dimethylaminobenzoate 0.2 g Diazo resin 1.0 g Durimer AC-10L (Polyacrylic acid 40% by weight aqueous solution, manufactured by Nihon Pure Chemical Co., Ltd.) 0.6 g Florard FC430 (fluorinated surfactant, 3M) 0.03 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.2 g 2-Methoxyethanol 180.0 g <Preparation of photosensitive lithographic printing plate samples 2-5> In the preparation of photosensitive lithographic printing plate sample 1, the alkali-soluble acrylic copolymer 1 in the photosensitive liquid composition Polymer 2
Photosensitive lithographic printing plate sample 1 except that each of
Photosensitive lithographic printing plate samples 2 to 5 were prepared in the same manner as in.

<< Evaluation of Photosensitive Lithographic Printing Plate Sample >> The obtained photosensitive lithographic printing plate sample was treated with Eastman Kodak step tablet (one step transmission density difference 0.15) and negative image film original. 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 a vacuum, and also by simply press-bonding without making 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 in the solid portion of the printed material, and the printing durability was evaluated by determining the number of printed sheets at that time.
The obtained results are also shown in Table 2.

[0098]

[Table 2] Example 2 <Preparation of photosensitive lithographic printing plate sample 6> On the support described in Example 1, a photosensitive solution having the following composition was dried at a dry weight of 1.6.
It was coated so as to be g / m ² and dried under an air stream at 80 ° C. for 2 minutes to prepare a photosensitive lithographic printing plate sample 6. Photosensitive solution composition Alkali-soluble acrylic copolymer 1 7.0 g Trimethylolpropane triacrylate 3.0 g Polyethylene glycol (molecular weight 2,000) 0.2 g 2,4-Diethylthioxanthone 0.5 g 4-Dimethylaminoethyl benzoate 0 .2 g Diazo resin 1.0 g Julimer AC-10L (40% by weight polyacrylic acid aqueous solution, manufactured by Nippon Pure Chemical Co., Ltd.) 0.6 g Florard FC430 (fluorine-based surfactant, 3M) 0.03 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.2 g 2-methoxyethanol 180.0 g

<Preparation of photosensitive lithographic printing plate sample 7> In preparation of photosensitive lithographic printing plate sample 6, polyethylene glycol (molecular weight 2,000) was replaced with polyethylene glycol (molecular weight 6,000) in the photosensitive liquid composition. A photosensitive lithographic printing plate sample 7 was prepared in the same manner as the photosensitive lithographic printing plate sample 6 except for the above.

<Preparation of photosensitive lithographic printing plate sample 8> In preparation of photosensitive lithographic printing plate sample 6, polyethylene glycol (molecular weight 2,000) was replaced with polypropylene glycol (molecular weight 1,500) in the photosensitive liquid composition. A photosensitive lithographic printing plate sample 8 was prepared in the same manner as the photosensitive lithographic printing plate sample 6 except for the above.

<< Evaluation of Photosensitive Lithographic Printing Plate Sample >> Example 1
The photosensitive lithographic printing plate sample was evaluated in the same manner as in.
Table 3 shows the obtained results.

[0102]

[Table 3]

[0103]

INDUSTRIAL APPLICABILITY The photopolymerizable composition of the present invention does not vary in sensitivity even in the presence of oxygen without using an oxygen barrier layer, has high sensitivity, and has excellent printing durability. ing.

 ─────────────────────────────────────────────────── ─── 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 (8)

[Claims] 1. In a photopolymerizable composition containing a polymerizable compound having an addition polymerizable unsaturated bond, a photopolymerization initiator and an alkali-soluble polymer compound, the alkali-soluble polymer compound is represented by the following general formula [I]. A photopolymerizable composition, which is an alkali-soluble polymer compound having a side chain having a repeating structural unit represented by: Embedded image [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group. ] 2. The photopolymerizable composition according to claim 1, further comprising a diazo compound. 3. The photopolymerizable composition according to claim 1, wherein the alkali-soluble polymer compound is a compound having a phenolic hydroxyl group in the molecule. 4. A photopolymerizable composition containing a polymerizable compound having an addition polymerizable unsaturated bond, a photopolymerization initiator and an alkali-soluble polymer compound, and at least one selected from polypropylene glycol and polyethylene glycol. A photopolymerizable composition, which further comprises a compound. 5. The photopolymerizable composition according to claim 4, further comprising a diazo compound. 6. The photopolymerizable composition according to claim 4 or 5, wherein the alkali-soluble polymer compound is a compound having a phenolic hydroxyl group in the molecule. 7. A photosensitive lithographic printing plate having a photosensitive layer obtained by coating the photopolymerizable composition according to claim 1 on a support having a hydrophilic surface. . 8. A method for developing a photosensitive lithographic printing plate, which comprises developing the photosensitive lithographic printing plate according to claim 7 with a developer containing substantially no organic solvent.