JPH03260650A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To provide the improved sensitization characteristic of the surface of the planographic printing plate and the enhanced inking property thereof and to enhance the film strength and sentivity thereof by incorporating a specific high-polymer compd. into a photosensitive layer. CONSTITUTION:This planographic printing plate is formed by incorporating the high-polymer compd. having the structure of formula as a repeating unit in the molecule as a sensitizing agent into the photosensitive layer. In the formula, R<1> denotes 3 to 18C alkyl, 3 to 18C alkenyl, etc.; R<2> denotes a substituent having an ethylenic unsatd. bond; R<3>, R<4> denote H, 1 to 4C alkyl, etc. This compd. is synthesized by a method for esterifying the phenolic OH of the polycondensate of a phenol deriv. (e.g.: p-tert-octyl phneol) and a carbonyl compd. (e.g.: formaldehyde) by a compd. having a substituent R<2> (e.g.: methacrylic acid chloride).

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a photosensitive lithographic printing plate.

[Background of the invention]

Various photosensitive lithographic printing plates (hereinafter also referred to as 28th plate as appropriate) have been proposed in the past.

For example, photosensitive lithographic printing plates having a photosensitive layer containing a diazo resin as a photosensitive compound have been proposed.

For example, in the case of a negative type photosensitive printing plate, the photosensitive printing plate is usually irradiated with light through a negative image, etc., and the irradiated area is polymerized or crosslinked to make it insoluble in a developer, and then developed. The areas not irradiated with light are eluted into a developing solution, and each area is formed into an image area that repels water and receives oil-based ink, and a non-image area that receives water and repels oil-based ink. Commonly used.

However, conventional photosensitive lithographic printing plates using diazo resin, such as conventional negative PS plates, generally have low oil sensitivity on the surface, resulting in insufficient ink receptivity during printing and loss at the beginning of printing. There were problems such as a large amount of paper being produced.

In order to avoid this problem, a technique using a fat sensitizing agent is known, and such a technique is proposed, for example, in Jikai No. 55-527.

[Problem that the invention seeks to solve]

However, in the technique using a liposensitizing agent, the liposensitizing agent may be eluted during development, impairing the effect. In order to achieve a sufficient sensitizing effect, it is advantageous to contain the sensitizing agent near the surface of the printing plate, so this problem is unavoidable when using a sensitizing agent that easily dissolves into the developer. I can say it. In addition, the inclusion of a fat-sensitizing agent may cause problems such as a decrease in film strength and a decrease in sensitivity. This problem is particularly serious when a condensation-type sensitizing agent such as novolak, which is commonly used in positive-working PS plates, is used in negative-working 28-print plates.

An object of the present invention is to solve the problems of the prior art described above, and to provide a photosensitive lithographic printing plate that has a high surface oil sensitivity, good ink receptivity, excellent film strength, and high sensitivity. It is.

[Means and effects for solving the problems] The above-mentioned object of the present invention is to provide a polymer compound (hereinafter appropriately referred to as "the polymer of the present invention") having a structure represented by the following general formula (I) as a repeating unit in the molecule. This is achieved by a photosensitive lithographic printing plate characterized by containing a molecular compound (sometimes referred to as "molecular compound") in the photosensitive layer.

4 However, in general formula (I), R1 represents an alkyl group having 3 to 18 carbon atoms, an alkenyl group having 3 to 18 carbon atoms, or an aryl group. R2 represents a substituent that represents an ethylenically unsaturated bond.

R3 and R4 represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.

Examples of the alkyl group having 3 to 18 carbon atoms represented by R1 include a butyl group having 4 carbon atoms (n-butyl group, tert-butyl group, etc.), octyl group having 8 carbon atoms (
tert-octyl group, etc.) can be preferably used. The alkenyl group represented by R1 is preferably 1-propenyl, allyl, 2-butenyl, or the like. The aryl group represented by R1 preferably has 6 to 18 carbon atoms, such as phenyl, hensyl, and p-+ to lyl groups.

When the number of carbon atoms in the alkyl group is 2 or less, the oil-sensitizing effect is small. Further, if the number of carbon atoms is 19 or more, the solubility in a developer decreases and developability deteriorates.

The above R3 and R4 are preferably a hydrogen atom, a lower alkyl group such as a methyl group, an ethyl group, a propyl group, or a phenyl group.

Examples of the substituent having an ethylenically unsaturated bond represented by R2 include acrylic, methacryl, vinyl, substituted vinyl,
Preferred groups include allyl, substituted allyl, crotyl, and balastyryl (alkyl groups are preferred as substituents for vinyl and allyl).

Moreover, it is preferable that the above R1 and OR2 are in para positions with respect to each other.

The polymer compound of the present invention functions as a fat-sensitizing agent and contains a polymerizable ethylenically unsaturated bond in the molecule, so it hardens upon exposure to light and its effectiveness decreases due to elution during development processing. In addition, it can exhibit the effect of preventing a decrease in sensitivity and film strength.

The polymer compound of the present invention can be effectively used for both the negative type 113 plate and the positive type R8 plate. You can solve problems like this.

The polymer compound of the present invention is contained in the photosensitive layer of the photosensitive lithographic printing plate of the present invention, and the content of the polymer compound of the present invention is 1 to 20% by weight in the photosensitive layer. It is preferable to

In the synthesis of this polymer compound, -C formula (II)
Introducing a substituent containing a polymerizable ethylenically unsaturated bond into the phenolic resin of the resin obtained by polycondensation of the phenol derivative represented by and the carbonyl compound represented by the general formula (I[l) It is preferable to use the method of Specifically, as the introduction method, a method of esterifying or etherifying the phenolic OH in the resin using an acid chloride, alkenyl chloride, alkenyl bromide, etc. having an ethylenically unsaturated bond is preferably used. .

General formula (II) General formula (I[l) 3 Examples of compounds represented by general formula (II) include p-n
-propylphenol, p-1-propylphenol,
Examples include p-n-butylphenol, p-tert-butylphenol, p-tert-octylphenol, p-phenylphenol, p-phenoxyphenol, and benzyloxyphenol.

Examples of the compound represented by the general formula (III) include formaldehyde, acetaldehyde, propanal, butanal, benzaldehyde, acetone, methyl ethyl ketone, and 3-pentanone.

Next, a synthesis example of the polymer compound of the present invention will be described.

Synthesis Example-1 320 g of p-tert-octylphenol, 105 g of 37% formaldehyde aqueous solution, 2.0 g of oxalic acid,
The mixture was placed in a three-necked flask set in an oil bath, and the temperature was raised while stirring. It foamed violently at around 90°C, and after being temporarily cooled, the temperature was raised again to bring the internal temperature to 105'C.

After reacting for about 3 hours, the temperature was raised to 200°C, and the temperature was increased to 100°C.
The pressure was reduced to mmHg, and the residual supernatant was distilled off.

After IO minutes, the reaction was stopped, and the reaction product was poured into a Teflon vat and solidified to obtain a polymer compound A.

Next, polymer compound A was dissolved in 1000 g of dioxane,
123 g of pyridine was added, and 162 g of methacrylic acid chloride was gradually added dropwise while cooling with water and stirring vigorously.

After stirring for 2 hours after dropping, add salt v! Water containing loOmZ 1
The reaction mixture was poured into an oven, and the precipitated polymer was taken out in an oven and dried to obtain a polymer compound B.

The polymer compound B is represented by the general formula (I) and corresponds to the polymer compound of the present invention. On the other hand, polymer compound A is a comparative polymer compound.

Next, the photosensitive layer of the photosensitive lithographic printing plate of the present invention [1,
In addition to the polymer compound of the present invention that functions as an oil sensitizing agent,
A compound having a polymerizable unsaturated bond can be contained in the molecule.

Examples of such compounds having a polymerizable unsaturated bond in the molecule include molecules having a boiling point of 100°C or higher at room temperature and at least one addition-polymerizable unsaturated group in each molecule of 1310.000 or less. monomers or oligomers can be used.

Specifically, such oligomers are
Polyethylene glycol mono(meth)acrylate, polypropylene glycol nanano(meth)acrylate,
Monofunctional acrylates and methacrylates such as phenoxyethyl (meth)acrylate; polyethylene glycol di(meth)acrylate, polypropylene di(meth)acrylate, trimethyl di(meth)acrylate, neopentyl glycol di(meth)acrylate, penta Erythryl tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythryl hexa(meth)acrylate, hexanediol di(meth)acrylate, tri-
(Acryloyloxyethyl) isocyanurate, a product obtained by adding ethylene oxide or propylene oxide to a polyhydric alcohol such as glycerin or trimethylolethane and then converting it into (meth)acrylate, JP-B No. 48-41
No. 708, Japanese Patent Publication No. 50-6034, Japanese Patent Publication No. 51-37
Urethane acrylates as described in each specification of No. 193, JP-A No. 48-64183, JP-B No. 49-Sho.
Examples include polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates prepared by reacting an epoxy resin with (meth)acrylic acid, which are described in Japanese Patent Publication No. 43191 and Japanese Patent Publication No. 52-30490. Furthermore, for details, see the Japan Adhesive Association Vol.
20. No. 7.300-308 It is also possible to use polymerizable compounds introduced as true photocurable monomers and oligomers.

Moreover, it is preferable to use a photopolymerization initiator together with these compounds having a polymerizable unsaturated bond in the molecule.

As the photopolymerization initiator that can be contained in the photosensitive layer of the photosensitive lithographic printing plate of the present invention, any known photopolymerization initiator can be used, but preferred ones include thioxanthone, anthraquinone, and benzophenone. , benzoin type, benzoic acid ester type, etc.

Specifically, the following compounds are used.

In addition, as a polymerization initiator, a trihalomethyloxathiazole compound or a 5-t-lyazine trihalomethyl compound can also be preferably used. Examples of the photopolymerization initiator include the following compounds.

[1] [2] [4] In the present invention, when a photopolymerization initiator is used, it is preferably contained in the total photosensitive composition forming the photosensitive layer in an amount of 0.1 to 20%, and preferably 0.5 to 20%. It is particularly preferable that the content is 10%.

The photosensitive layer of the photosensitive lithographic printing plate of the present invention can contain a diazo resin as a photosensitive substance.

When a diazo resin is used in the present invention, any diazo resin may be used.

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

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

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

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

Specific examples of the aromatic compound containing a carboxyl group and/or hydroxyl group as a constitutional unit of the co-condensed diazo resin include benzoic acid, 0-chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, phthalate. Acid, terephthalic acid, diphenyl 6-acid, phenoxyacetic acid, p-methoxyphenylacetic acid, P-methoxybenzoic acid, 2.4-dimethoxybenzoic acid, 2.4-dimethylbenzoic acid, P-phenoxybenzoic acid, 4-anilinobenzoic acid Acid, 4(m-methoxyanilino)benzoic acid, 4-(pmethylbenzoyl)
Benzoic acid, 4-(p-methylanilino) Benzoic acid, 4
-phenylsulfonylbenzoic acid, phenol, (o, m
, p)-cresol, xylenol, resorcinol, 2-
Methylredulucin, (o, m, p)-methoxyphenol, m-ethoxyphenol, catechol, phloroglycin, P-hydroxyethylphenol, naphthol,
Pyrogallol, hydroquinone, p-hydroxybenzyl alcohol, 4-chlororesorcinol, biphenyl-4,
4゛-diol, 1.2゜4-hensentriol, bisphenol A12゜4-dihydroxyhensiphenone, 2,3.4 trihydroxyhenzophenone, p-hydroxyacetophenone, 4,4-dihydroxydiphenyl ether, 4,4゛-dihydroxydiphenylamine, 4,4-dihydroxydiphenyl sulfide, cumylphenol, (o,rn,p)-chlorophenol,
(0,m,P)-bromophenol, salicylic acid, 4-
Methylsalicylic acid, 6-methylsalicylic acid, 4-ethylsalicylic acid, 6-propylsalicylic acid, 6-laurylsalicylic acid, 6-styarylsalicylic acid, 4,6-siftylsalicylic acid, p-hydroxybenzoic acid, 2-methyl 4-
Hydroxybenzoic acid, 6-methyl-4-hydroxybenzoic acid, 2.6-dimethyl-4-hydroxybenzoic acid, 2
．． 4-dihydroxybenzoic acid, 2,4-dihydroxydi-
6-methylbenzoic acid, 2゜6-dihydroxybenzoic acid,
2.6-cyhydroxy-4-benzoic acid, 4-chloro-2
, 6-dihydroxybenzoic acid, 4-methoxy-2,6-
Dioxybenzoic acid, gallic acid, phloroglucincarboxylic acid, 2,4.5-trihydroxybenzoic acid, m-galloyl gallic acid, tannic acid, m-hendiyl gallic acid, m-
(P-tolyl) gallic acid, protocatechoyl-gallic acid, 4,6-cyhydroxyphthalic acid, (2,4-dihydroxyphenyl) acetic acid, (2,6-dihydroxyphenyl) acetic acid, (3,4,5 -trihydroxyphenyl)acetic acid, p-hydroxymethylbenzoic acid, P-hydroxyethylbenzoic acid, 4-(p-hydroxyphenyl)methylbenzoic acid, 4-(0-hydroxybenzoyl)benzoic acid, 4-(2,4 -dihydroxybenzoyl)benzoic acid, 4-(p-hydroxyphenoxy)benzoic acid, 4
-(p-hydroxyanilino)benzoic acid, bis(3-carboxy-4-hydroxyphenyl)amine, 4-(p-
-hydroxyphenylsulfonyl)benzoic acid, 4-(p
-hydroxyphenylthio)benzoic acid and the like. Particularly preferred among these are salicylic acid, p
-hydroxybenzoic acid, p-methoxybenzoic acid, and metachlorobenzoic acid.

As the aromatic diazonium compound used as the structural unit of the co-condensed diazo resin, diazonium salts such as those listed in Japanese Patent Publication No. 49-48001 can be used, but diphenylamine-4-diazonium salts are particularly preferred. Diphenylamine 4-diazonium salts are 4
-Amino-diphenylamines, such 4-amino-diphenylamines include 4-amino-diphenylamines.
Aminodiphenylamine, 4-amino-3-methoxydiphenylamine, 4-amino-2-methoxydiphenylamine, 4'-amino-2-methoxy-diphenylamine, 4'-amino-4-methoxydiphenylamine, 4
-amino-3-methyldiphenylamine, 4-amino-
3-ethoxydiphenylamine, 4-amino-3-β-
Examples include hydroxy-ethoxydiphenylamine, 4-aminodiphenylamine-2-sulfonic acid, 4-aminodiphenylamine-2-carboxylic acid, and 4-amino-diphenylamine-2'-carboxylic acid. Particularly preferred are 3-methoxy4-amino-diphenylamine and 4-aminodiphenylamine.

When using a co-condensed diazo resin, it is preferable to use one represented by the following general formula (IV).

In the -C formula [■], A is a group derived from an aromatic compound having at least one of a carboxyl group and a hydroxyl group, and examples of such aromatic compounds include those exemplified above.

In the formula, R11, R12 and R13 represent a hydrogen atom, an alkyl group or a phenyl group, R represents a hydrogen atom, an alkyl group or a phenyl group, and X represents a counter anion. n preferably represents a number from 1 to 200.

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

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

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

The above-mentioned co-condensed diazo resins and condensed diazo resins used in combination with these or independently as diazo resins are:
Known methods such as Photographic Science and Engineering (Photo, Sci, E.
Diazonium was prepared in sulfuric acid, phosphoric acid, or hydrochloric acid according to the method described in U.S. Pat. It is obtained by polycondensation of salts, aromatic compounds having carboxyl and hydroxyl groups, and aldehydes, such as paraformaldehyde, acetaldehyde, henzaldehyde, or ketones, such as acetone and acetophenone.

In addition, aromatic compounds, aromatic diazo compounds, and aldehydes or ketones having carboxyl groups and/or hydroxyl groups in their molecules can be freely combined with each other, and two or more of each can be co-condensed. It is also possible to do so.

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

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

The counter anion of the diazo resin includes an anion that stably forms a salt with the diazo resin and makes the resin soluble in an organic solvent. Those that form such anions include organic carboxylic acids such as decanoic acid and benzoic acid, organic phosphoric acids such as phenylphosphoric acid, and sulfonic acids; typical examples include methanesulfonic acid, Chloroethanesulfonic acid, dodecanesulfonic acid, Hensensulfonic acid, toluenesulfonic acid, mesitylenesulfonic acid, and an-1-laquinonesulfonic acid, 2-hydroxy-4-
Aliphatic and aromatic sulfonic acids such as methoxyhensiphenone-5-sulfonic acid, hydroxysulfonic acid, 4-acetylbenzenesulfonic acid, dimethyl-5-sulfoisophthalate, 22', 4.4''-tetrahydroxyhensif hydroxyl group-containing aromatic compounds such as enone, 1.2.3-trihydroxyhensophenone, 2.2', 4-1-lyhydroxybenzophenone, halogenated Lewis acids such as hexafluorophosphoric acid and tetrafluoroboric acid, C
Examples include perhalogen acids such as 1O2, 10, and the like. However, it is not limited to this.

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

The above-mentioned co-condensed diazo resin can have an arbitrary molecular weight by varying the molar ratio of each monomer and the condensation conditions. In the present invention, in general, those having a molecular weight of about 400 to io, o o o can be effectively used, more preferably about 800 to 5.
000 is appropriate.

In addition, in the present invention, when using a diazo resin, other than the above-mentioned co-condensed diazo resins that can be preferably used as a diazo resin, for example, the above-mentioned Photographic Science and Engineering (Photo
, Sci, Eng,) Volume 17, Page 33 (I973
), and U.S. Patent Nos. 2,063,631 and 2,679.
, No. 498, No. 3.050.502, JP-A-59-78340, etc., a diazo compound and an active carbonyl compound, such as formaldehyde, acetaldehyde or benzaldehyde, are mixed with sulfuric acid, Examples include diazo resins obtained by condensation in acidic media such as phosphoric acid and hydrochloric acid, diazo compounds and diphenyl resins whose production method is described in Japanese Patent Publication No. 49-4001.

Among the above, the diazo resin that can be preferably used in the present invention is represented by the following general formula (V), and more preferably contains 20 mol% or more of a resin in which n in each formula is 5 or more, more preferably , 20 to 60 mol%. During the ceremony,
R11~R1ff, R,)<, n represents the general formula (
It has the same meaning as in IV).

112 formula (V) Nioiite, R11, plg and RI
Examples of the alkyl group and alkoxy group of 3 include an alkyl group having 1 to 5 carbon atoms and an alkoxy group having 1 to 5 carbon atoms, and examples of the alkyl group of R include 1 to 5 carbon atoms.
~5 alkyl groups are mentioned.

General formula (V) Such a photosensitive diazo resin can be produced according to a known method, for example, the method described in the above-mentioned Photographic Science and Engineering and other U.S. patent specifications cited above. .

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

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

Next, the photosensitive layer of the photosensitive lithographic printing plate of the present invention may contain other polymeric compounds as a binder resin in addition to the polymeric compound of the present invention as a fat-sensitizing agent. As such polymer compounds, alkali-soluble and
Swellable polymer compounds can be used. Here, the alkali-soluble/swellable polymer compound is one that is alkali-soluble, alkali-swellable, or has both properties. One or more kinds of such polymer compounds can be arbitrarily used.

As the alkali-soluble polymer compound, it is preferable to use one that dissolves into an alkaline solution, for example, an alkaline solution having a pH of 12.0 or higher at 25°C.

In addition, as the alkali-swellable polymer compound, it is preferable to use a compound that expands in volume when the liquid permeates in an alkaline solution, and when it is coated on a support, it can be easily peeled off from the support. Can be used.

In carrying out the present invention, GPC using a polystyrene standard is used to specify the molecular weight of various polymer compounds used.
The molecular weight value measured by can be used.

That is, the weight average molecular weight can be measured by GPC (gel permeation chromatography), and the number average molecular weight MN and weight average molecular weight MW can be calculated by Morio Tsuge, Tatsuya Miyabayashi, Masayuki Tanaka, "Japan Chemical Society Journal”8
By the method described on pages 00 to 805 (I972),
This can be done by leveling the peaks of the oligomer region (connecting the center lines of the peaks and valleys).

When using an alkali-soluble/swellable polymer compound in the present invention, for example, the following can be used. That is, examples of polymer compounds that can be used include polyamide, polyether, polyester, polycarbonate,
Examples include polystyrene, polyurethane, polyvinyl chloride and its copolymers, polyvinyl butyral resin, polyvinyl formal resin, shellac, epoxy resin, phenol resin, acrylic resin, and the like.

Preferably, copolymers of monomers shown in (I) to (I2) below, which are alkali-soluble and swellable polymer compounds, are preferred.

(I) N(4-
hydroxyphenyl)acrylamide or N-(4-
hydroxyphenyl) methacrylamide, o-, m-
, p-hydroxystyrene, o-, m-p-hydroxyphenyl-acrylate or -methacrylate.

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

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

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

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

(6) Acrylamide, methacrylamide, N-methylolmethacryamide, N-methylolmethacryamide, N-
Ethyl acrylamide, N-hexyl acrylamide,
N-cyclohexyl acrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N
- Acrylamides or methacrylamides such as nitrophenylamide and N-ethyl-N-phenylacrylamide.

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

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

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

(I0) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.

(I1) Olefins such as ethylene, propylene, isobutylene, phtadiene, and isoprene.

(I2) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylatel, etc.

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

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

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

In the present invention, when a copolymer which is an alkali-soluble/swellable polymer compound is used in the photosensitive layer, the following copolymers are particularly preferred.

That is, in the molecular structure, (a) 1 to 50 mol% of a structural unit having an alcoholic hydroxyl group and/or a structural unit having a phenolic hydroxyl group, (b) the following general formula (Vl) Ral CI (t-C-・・・・・・・・・5 to 40 mol% of the structural unit represented by (Vl)N (in the formula, Ral represents a hydrogen atom or an alkyl group), (c) the following general formula (■) Rzz CH2-C-・・・・・・・・・(■)0OR13 (In the formula, Rzz represents a hydrogen atom, a methyl group, or an ethyl group, and R23 is an alkyl group having 2 to 12 carbon atoms or an alkyl substituted It is preferable to use a polymer compound containing 25 to 60 mol% of the structural unit represented by (representing an aryl group), and whose weight average molecular weight is 20.000 to 20.000.
Even more preferred are copolymers with a molecular weight of 200,000.

Specific examples of the monomer forming the structural unit having an alcoholic hydroxyl group in (a) above include Japanese Patent Publication No. 52-736
Examples include (meth)acrylic acid esters and acrylamides such as the compounds shown in the following general formula (■) as described in No. 4.

Z4 CH, −−C−・・・・・・・・・ (■)COO+C
ll2CH07-H zs In the formula, R24 represents a hydrogen atom or a methyl group, RZ5 represents a hydrogen atom, a methyl group, an ethyl group, or a chloromethyl group, and n represents an integer of 1 to 10.

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

Preferably it is 2-hydroxyethyl (meth)acrylate.

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

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

Forming a structural unit represented by the general formula (VT),
Monomers having a cyano group in their side chains include acrylonitrile, methacrylonitrile, 2-pentenenitrile,
Examples include 2-methyl-3-butenenitrile, 2-cyanoethyl acrylate, o-m-p-cyanostyrene, and the like. Preferred are acrylonitrile and methacrylonitrile.

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

The heptadmer having a carboxyester group in its side chain and forming the structural unit represented by the general formula (■) is as follows:
Examples include ethyl acrylate, ethyl methacrylate, propyl acrylate, butyl acrylate, amyl acrylate, amyl methacrylate, hexyl acrylate, octyl acrylate, 2-chloroethyl acrylate, 2hydroxyethyl acrylate, glycidyl acrylate, and the like. The unit formed by the heptads is preferably 25 to 60 mol% in the polymer compound,
More preferably, it is selected from the range of 35 to 60 mol%.

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

Examples of the polymer forming the structural unit having a carboxyl group include methacrylic acid, acrylic acid, maleic anhydride, maleic acid, and the like. The amount of 1,000 mol is selected from the range of 2 to 30 mol%, preferably 5 to 15 mol% in the polymer compound.

In addition, each of the above structural units is not limited to the unit formed from 1,000 units mentioned as a specific example.

When using an alkali-soluble/swellable polymer compound in the present invention, the solid content of the photosensitive composition constituting the photosensitive layer is preferably usually 40 to 99% by weight, more preferably 5% by weight.
The content is 0 to 95% by weight.

Further, in the present invention, when a photosensitive diazo resin is used, it is preferably contained in an amount of usually 1 to 60% by weight, more preferably 3 to 30% by weight.

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

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

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

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

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

That is, for example, Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.)
, crystal violet, brilliant green, ethyl violet, methyl violet, methyl green, erythrosin B1 basic tsuksin, malachite green, oil red, m-cresol purple, rhodamine B1 auramine, 4-p-dimethylaminophenyl imino naphthoquine, cyano- Triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthine-based, iminonaphthoquinone-based, azomethine-based, or anthraquinone-based dyes represented by p-diethylaminophenylacetanilide are examples of dyes that change color from colored to colorless or to a different color. It can be mentioned as follows.

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

When the above-mentioned color change agent is contained in the photosensitive layer, the color change agent is usually about 0.5
The content is preferably about 10% by weight, more preferably about 1 to 5% by weight.

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

Examples of additives include alkyl ethers (e.g., ethyl cellulose, methyl cellulose), fluorine surfactants, and nonionic surfactants (e.g., Pluroni Nc L64 (manufactured by Asahi Denka Corporation) to improve coating properties).
], a plasticizer to impart flexibility and abrasion resistance to the coating film (
For example, butyl phthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, diptyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate,
tetrahydrofurfuryl oleate, oligomers and polymers of acrylic acid or methacrylic acid), fat-sensitizing agents for improving the fat-sensitivity of image areas (for example, JP-A-55
Examples include alcohol-based half esters of styrene-maleic anhydride copolymers described in Japanese Patent Publication No. 527). The amount of these additives added varies depending on the object and purpose of use, but is generally preferably 0.01 to 30% by weight based on the total solid content.

In order to obtain the photosensitive lithographic printing plate of the present invention, predetermined amounts of the polymer compound of the present invention and other various additives such as a diazo resin, an alkali-soluble/swellable polymer compound, and other additives are added as necessary. Suitable solvent (methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethyl formamide,
A printing plate can be obtained by dissolving the photosensitive composition in dimethyl sulfoxide, water, a mixture thereof, etc. to prepare a coating solution, and coating the photosensitive composition on a support and drying it. The concentration of the photosensitive composition during coating is preferably in the range of 1 to 50% by weight. In this case, the coating amount of the photosensitive composition is preferably about 0.2 to 10 g/%.

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

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

For example, a method in which the surface of an aluminum plate is grained and then treated with a silicate (U.S. Patent No. 2.714°066), a method in which it is treated with an organic acid salt (U.S. Pat.
066), treatment with phosphonic acids and their derivatives (U.S. Pat. No. 3,220,832), treatment with potassium hexafluorozirconate (U.S. Pat. No. 2,946,683), anodizing There are methods such as a method of treating with an aqueous solution of an alkali metal silicate after anodization (US Pat. No. 3,181,461), and the like.

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

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

When carrying out sealing treatment in carrying out the present invention, preferably a sodium silicate aqueous solution with a concentration of 0.1 to 3% is added at a temperature of 8.
0-95° CT: Perform this treatment by immersing for 10 seconds to 2 minutes. More preferably, it is then immersed in water at 40-95°C.
Process by soaking for 2 to 2 minutes.

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

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

Any method can be used to develop the image-exposed photosensitive lithographic printing plate (PS plate), and for example, various conventionally known methods can be used.

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

Any developer can be used to develop the photosensitive lithographic printing plate of the present invention as long as it can develop the plate.

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

The specific organic solvent herein refers to a solvent that can dissolve or swell the non-exposed area (non-image area) of the photosensitive layer when it is contained in the developer, and that is soluble in water at room temperature (20°C). An organic solvent having a solubility in the organic solvent of 10% by weight or less is preferred.

Such organic solvents only need to have the characteristics described above, and are not limited to the following, examples of which include ethyl acetate, propyl acetate, etc. carboxylic acid esters such as , butyl acetate, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl acetate, butyl levulinate; ketones such as ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone; ethylene glycol monobutyl ether, ethylene Alcohols such as glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol; alkyl-substituted aromatic hydrocarbons such as xylene; methylene dichloride, ethylene dichloride, mono These include halogenated hydrocarbons such as chlorobenzene. These organic solvents may be used alone or in combination of two or more. Among these organic solvents, ethylene glycol monophenylnitere and benzyl alcohol are particularly effective. Further, the content of these organic solvents in the developer is preferably approximately 1 to 20% by weight, particularly 2 to 20% by weight.
More preferable results are obtained when the amount is 10% by weight.

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

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

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

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

If such a developer is brought into contact with a photosensitive lithographic printing plate after development and exposure, or is rubbed with the developer, the exposed areas of the photosensitive layer will be adversely affected after 10 to 60 seconds at room temperature to 40°C. The photosensitive layer in non-exposed areas is completely removed without causing any damage.

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

〔Example〕

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

In each of the following examples, an alkali-soluble/swellable polymer compound was used as the binder resin, and a diazo resin was used as the photosensitive substance, so these will be explained.

＼ Person 1 N-(4-hydroxyphenyl) methacrylamide 1
7.7 g, methacrylic acid 8.6 g, acrylonitrile 10.6 g, ethyl acrylate 60.0 g
, and 1.64 g of abbisisobutyronitrile were dissolved in a 1:1 acetone-methanol mixed solution 130+111, the atmosphere was purged with nitrogen, and the mixture was heated at 60°C for 6 hours.

After the reaction was completed, the reaction solution was poured into water 51 with stirring, and the resulting white precipitate was filtered and dried to obtain 87 g of polymer compound (I).

When the molecular weight of this polymer compound (I) was measured by gel permeation chromatography (hereinafter abbreviated as GPC, polystyrene standard), the weight average molecular weight was 82.000. The weight average molecular weight MW was calculated by GPC (gel permeation chromatography) according to the method described in Morio Takuue, Tatsuya Miyabayashi, and Masayuki Tanaka, "Journal of the Chemical Society of Japan," pages 800 to 805 (1972). This can be done by leveling the peaks of the oligomer region (connecting the center lines of the peaks and valleys).

2-Hydroxyethyl methacrylate 13.0 g,
Methacrylic acid 8.6g, acrylonitrile 10.6g
g, 60.0 g of ethyl acrylate, and 1.64 g of azobisisobutyronitrile were dissolved in 130 mff1 of an acetone-methanol 1:1 mixed solution, the atmosphere was replaced with nitrogen, and the mixture was heated at 60°C for 6 hours.

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

When the molecular weight of this polymer compound (2) was measured by GPC, the weight average molecular weight was 67,000.

14.5 g of A p-diazodiphenylamine sulfate of Diazo 181 was dissolved in 40 g of concentrated sulfuric acid under water cooling. 1.05 g of paraformaldehyde was slowly added to the reaction solution. At this time, the addition was carried out so that the reaction temperature did not exceed 10°C. Thereafter, stirring was continued for 2 hours under water cooling. This reaction mixture was poured into 500 ml under water cooling.

was added dropwise to ethanol, and the resulting precipitate was filtered off.

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

75 g of JtlL2 (') Jinkai-p-diazodiphenylamine sulfate 21 and 3.5 g of p-hydroxybenzoic acid were added to 90 g under water cooling.
of concentrated sulfuric acid. To this reaction solution, 2.7 g of rose formaldehyde was slowly added.

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

This reaction mixture was added dropwise to If's ethanol under water cooling, and the resulting precipitate was filtered off. After washing the precipitate with ethanol, the precipitate was dissolved in 200 g + 42 g of pure water, and to this solution was added an aqueous solution in which 10.5 g of zinc chloride was dissolved. After filtering the resulting precipitate, it was washed with ethanol and
It was dissolved in I111 pure water. Add 13.7 g to this liquid.
ammonium hexafluorophosphate? The resulting aqueous solution was added, and the resulting precipitate was filtered, washed with water and ethanol, and then dried at 25°C for 3 days to obtain diazo resin 2.

Next, examples will be described together with comparative examples.

Example 1. 2 and Comparative Example 1. 2. On a grained, anodized aluminum plate, Table 1
The photosensitive solution shown in
A photosensitive planographic printing plate sample was prepared.

A negative transparent original image was placed on the obtained sample and exposed for 30 seconds from a distance of 60 cm using a 2 kW metal halide lamp.
27 in Konica 23rd edition developer 5DN-21 (manufactured by Konica ■)
After immersion in °Cl2O for seconds, development was performed by rubbing lightly with absorbent cotton.

The sensitivity of each sample was compared by the number of solid steps when exposing and developing the original image using a Konica Step Tablet.

In addition, the obtained plate was prepared using Konica PS gum liquid 5GQ-3 (2
After drying, print on a Heidelberg GTO printing machine to compare how many sheets of paper are required until the gum in the image area is removed and normal ink is obtained. The meat quality was evaluated.

Further, the film strength of the image area was evaluated by comparing the number of sheets at the time when scratches were observed in the image area when printing was continued.

Each result is shown in Table-2.

From Table 2, it can be seen that in Example 1, the ink receptivity was improved compared to Comparative Example 1 without reducing the sensitivity and film strength.

On the other hand, it can be seen that in Comparative Example 2, although the ink receptivity was improved, the sensitivity and film strength were significantly lowered.

Moreover, in Example 2, ink receptivity, sensitivity, and film strength are all improved.

〔Effect of the invention〕

As described above, according to the present invention, a photosensitive lithographic printing plate with good ink receptivity could be obtained without reducing sensitivity or film strength.

Claims (1)

[Scope of Claims] 1. A photosensitive lithographic printing plate characterized in that a photosensitive layer contains a polymer compound having a structure represented by the following general formula (I) as a repeating unit in the molecule. General formula (I) ▲There are numerical formulas, chemical formulas, tables, etc.▼ However, in the general formula (I), R^1 is an alkyl group having 3 to 18 carbon atoms, or an alkenyl group having 3 to 18 carbon atoms, or Represents an aryl group. R^2 represents a substituent having an ethylenically unsaturated bond. R^3 and R^4 represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.