JP2001356474A - Original plate for planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for planographic printing plate which does not generate scum in a developing solution when developed and gives a planographic printing plate excellent in printing durability. SOLUTION: The original plate has a photopolymerizable layer containing a phthalocyanine pigment dispersed in a polymer having a group of formula (1) or the formula Y-Ar (2) (where R is a 1-30C hydrocarbon group; Y is a group which combines with the principal chain skeleton of the polymer; and Ar is a N-containing heteroaryl) in a side chain.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate precursor, and more particularly, to a lithographic printing plate which is free from scum in a developing solution and has excellent printing durability. It relates to a lithographic printing plate precursor.

[0002]

2. Description of the Related Art Heretofore, many lithographic printing plate precursors utilizing a photopolymerization system have been known. For example, a photopolymerization layer containing an addition-polymerizable compound containing an ethylenic double bond and a photopolymerization initiator is known. A lithographic printing plate precursor having the following formula is known. In recent years, with the development of the lithographic printing plate precursor technology described above,
For example, there is a demand for adaptation to non-contact type projection exposure plate making, visible light laser plate making, and the like. Here, 488 nm light of an Ar ⁺ laser, 532 nm light of a YAG-SHG laser, and the like are promising as visible light lasers. After exposing the image with the visible light laser or the like, the unexposed portion is removed by a development process to produce a lithographic printing plate having an image portion and a non-image portion. In order to make it easier to confirm the image forming properties of the lithographic printing plate, it is common to include a plate test agent (colorant, dye or pigment) in the photopolymerized layer of the lithographic printing plate precursor.

[0003] As a plate inspection agent to be contained in a photopolymerization layer (hereinafter also referred to as a photosensitive layer) of a photopolymerization type lithographic printing plate precursor, it exhibits a blue color suitable for plate inspection and is used for image exposure for photopolymerization. Phthalocyanine pigments are used because they have the advantage of not absorbing laser light. In order to enhance the dispersibility of the phthalocyanine, it is common to coat a polymer or to substitute an acid group, a base, or the like on the pigment surface. However, the lithographic printing plate precursor as described above,
In the case of processing with a developing solution after image exposure, there is a problem that scum is generated in the developing solution, the developing solution becomes unstable, and the printing durability of a lithographic printing plate after plate making is deteriorated.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention overcomes the above-mentioned problems of the prior art, does not cause any scum in the developing solution due to the development process, and is resistant to lithographic printing plates. It is an object of the present invention to provide a lithographic printing plate precursor excellent in printability.

[0005]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies on a phthalocyanine pigment dispersant used as a coloring agent to be contained in a photopolymerizable layer. It has been found that the above disadvantages of the prior art can be overcome by employing a polymer having a side chain. That is, the present invention is a lithographic printing plate precursor having a photopolymerization layer containing a polymer-dispersed phthalocyanine pigment having a group represented by the following general formula (1) or (2) in a side chain.

[0006]

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(Wherein, R represents an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, and Y represents a linking group to the polymer main chain skeleton. Ar represents a substituent. Represents a heteroaryl group containing a nitrogen atom.

Conventionally, a photo-radical polymerization type image forming material has various coloring agents for distinguishing between an image area and a non-image area.
(Dyes and pigments) have been added. In the case of a photo-radical polymerization system as a preferred coloring agent, desensitization by radical scavenging or unnecessary interaction with an initiation system (initiator alone or a combination of a sensitizing dye and an initiator) (energy transfer or energy transfer) is preferable. For the purpose of avoiding desensitization due to (electron transfer), so-called pigments have been used which are dispersed in the photopolymerization layer as an aggregate that maintains a crystalline state without being molecularly dispersed. Conventionally, allyl methacrylate / methacrylic acid copolymer has been used as a pigment-dispersed polymer for the purpose of improving dispersibility and not deteriorating sensitivity and printing durability, and a pigment dispersed with the polymer has been used. However, such a pigment / dispersion system accumulates in a developing solution, coagulates and sediments, and becomes a developing residue when developing processing is continued for a long time in a developing step for removing a non-image portion, which is a factor of destabilizing the developing processing. Had become.

As a result of investigating the above-mentioned problem of the development residue in the case of a photosensitive material of a photo-radical polymerization system which has a high reputation with high sensitivity, the main cause of the development residue is that of the colorant (pigment) contained in the photopolymer layer. It was found to be coagulation sedimentation. From these facts, in a radical photopolymerization system, as a result of searching for a new colorant that enables long-term development processing (improvement of processing stability) while maintaining high sensitivity, it was represented by the above general formula (1). By dispersing a phthalocyanine pigment as a colorant using a polymer having at least one of a structure represented by the following general formula and a structure represented by the general formula (2) in a side chain, the phthalocyanine pigment accumulates and aggregates in a developer. It has been found that it does not settle and does not become a developing residue. The dispersing polymer used in the present invention has a characteristic of easily coordinating with a metal and forming a complex. Therefore, in the polymer-dispersed phthalocyanine pigment of the present invention, it is presumed that the polymer acts on the metal part (Cu) of the phthalocyanine pigment, and the adsorptive power is increased, and the polymer does not deviate from the pigment even in the developer. Since coagulation and sedimentation do not occur, generation of development scum can be prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a lithographic printing plate precursor according to the present invention will be described in detail. As the phthalocyanine pigment, the phthalocyanine itself has the fastness (light fastness, heat resistance), and is suitable for a photopolymerization reaction.
There is no particular limitation as long as it has little absorption at 533 nm. For example, Pigment Blue 15: 3,
15: 4, 15: 6 and the like. The addition amount is preferably 10% or less of the total composition.

The phthalocyanine pigment dispersion polymer which is the most characteristic component of the present invention is at least one of a structure represented by the following general formula (1) and a structure represented by the following general formula (2): Is a polymer having in the side chain.

[0012]

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(Wherein, R represents an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, and Y represents a linking group to the polymer main chain skeleton. Ar represents a substituent. Represents a heteroaryl group containing a nitrogen atom which may be present.)

Examples of the hydrocarbon group having 1 to 30 carbon atoms include an alkyl group, an alkenyl group, an alkynyl group,
An aryl group or a heteroaryl group containing at least one hetero atom selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom is exemplified.

Specific examples of the alkyl group include a methyl group,
Ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group,
Undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 1-methylbutyl, isohexyl, 2- Ethylhexyl group, 2-
Examples thereof include a linear, branched, or cyclic alkyl group having 1 to 30 carbon atoms such as a methylhexyl group, a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-norbornyl group. Specific examples of the alkenyl group include a vinyl group, a 1-propenyl group, a 1-butenyl group,
1-methyl-1-propenyl group, 1-cyclopentenyl group, 1-cyclohexenyl group and the like having 1 to 3 carbon atoms
Up to 0 straight-chain, branched or cyclic alkenyl groups are mentioned.

Specific examples of the alkynyl group include an alkynyl group having 1 to 30 carbon atoms such as an ethynyl group, a 1-propynyl group, a 1-butynyl group and a 1-octynyl group. Specific examples of the aryl group include 1 to 4
One in which a benzene ring forms a condensed ring, and those in which a benzene ring and an unsaturated five-membered ring form a condensed ring, specific examples of which include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, Examples include an allyl group having 1 to 30 carbon atoms such as an indenyl group, an acenabutenyl group, a fluorenyl group, and a pyrenyl group.

The heteroaryl group containing at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur atoms includes at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur atoms. And a heteroaryl group in which one hydrogen atom on the heteroaromatic ring is removed. Specific examples of the heteroaromatic ring containing at least one heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom include pyrrole, furan, and furan.
Thiophene, pyrazole, imidazole, triazole, oxazole, isoxazole, oxadiazole, thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazole benzimidazole, anthranil, benzisoxazole, benzoxazole, benzothiazole, Purine, pyridine,
Examples include pyridazine, pyrimidine, pyrazine, triazine, quinoline, acridine, isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, pteridine and the like.

One or more of these hydrocarbon groups having 1 to 30 carbon atoms may be substituted with any substituent. Examples of the substituent include a monovalent nonmetallic atomic group other than hydrogen, and a halogen atom (-F, -Br,-
Cl, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N -Arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N,
N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N
-Alkylacylamino group, N-arylacylamino group, ureido group, N'-alkylureido group, N ',
N'-dialkylureido group, N'-arylureido group, N ', N'-diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N' -Alkyl-N-alkylureido, N'-alkyl-N-arylureido, N ', N'-dialkyl-N-alkylureido, N', N'-dialkyl-N-arylureido, N ' -Aryl-N-alkylureido group, N'-
Aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N ′
-Aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl -N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base group, alkoxycarbonyl group, Aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group,
N-alkyl-N-arylcarbamoyl, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, sulfo (-SO
₃ H) and its conjugated base group, alkoxy sulfonyl group,
Aryloxysulfonyl group, sulfinamoyl group, N-
Alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group,
N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group ,
N, N-diarylsulfamoyl group, N-alkyl-
N-arylsulfamoyl group, N-acylsulfamoyl group and its conjugate base group, N-alkylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ (alkyl)) and its conjugate base group, N-arylsulfonyl sulf Famoyl group (—SO ₂ NHSO ₂ (aryl)) and its conjugate base group, N-alkylsulfonylcarbamoyl group (—C
ONHSO ₂ (alkyl)) and its conjugate base group, N
-Arylsulfonylcarbamoyl group (-CONHSO
₂ (aryl)) and its conjugate base group, alkoxysilyl group (-Si (Oalkyl) ₃ ), aryloxysilyl group (-Si (Oaryl) ₃ ), hydroxysilyl group (-Si (OH) ₃ ) and its conjugate base group, a phosphono group (-PO ₃ H ₂₎ and its conjugated base group, a dialkyl phosphono group _{(-PO 3 (alkyl) 2)} , diaryl phosphono group _{(-PO 3 (aryl) 2)} , alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )), monoalkyl phosphono group (-PO ₃ H (alkyl)) and its conjugated base group, monoaryl phosphono group (-PO ₃ H
(Aryl)) and its conjugate base group, phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group, dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ ( aryl) _2), alkylaryl phosphono group (-OPO ₃ (alky
1) (aryl)), a monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group,
Monoarylphosphonooxy group (—OPO ₃ H (ary
1)) and its conjugate base group, cyano group, nitro group, aryl group, alkyl group, alkenyl group, and alkynyl group.

The linking group represented by Y includes an oxygen atom,
A functional group containing at least one hetero atom selected from the group consisting of a nitrogen atom and a sulfur atom, and includes a substituted or unsubstituted divalent hydrocarbon group having 1 to 30 carbon atoms.

Ar is a heteroaryl group containing a nitrogen atom, and specifically, optionally substituted pyrrole, pyridine, pyrazole, imidazole, triazole, tetrazole, isoxazole, oxazole,
Isothiazole, thiazole, thiadiazole, indole, carbazole, azaindole, indazole,
Nitrogen-containing heteroaromatic rings such as benzimidazole, benzotriazole, benzisoxazole, benzoxazole, benzothiazole, purine, pyridazine, pyrimidine, pyrazine, triazine, quinoline, isoquinoline, acridine, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, pteridine and the like. In which one hydrogen atom on the carbon atom constituting the above is removed to form a monovalent group.

The amount of the dispersing polymer to be added is preferably 50 to 200% by weight, more preferably 60 to 100% by weight, based on the phthalocyanine pigment. At the time of dispersion, the phthalocyanine pigment and the dispersion polymer are dispersed in a solvent such as cyclohexanone or 2-methoxypropanol for 10 to 10 minutes.
It is common to add to a concentration of 30% and disperse with a paint shaker or the like. The content of the phthalocyanine pigment in the photopolymerization layer is not particularly limited, but is preferably 0.1 to 1% by weight, more preferably
0.01 to 0.5 wt%, and more preferably,
0.03 to 0.3 wt%.

Next, components other than the phthalocyanine compound and the dispersing polymer contained in the photopolymerizable layer of the lithographic printing plate precursor according to the present invention will be described. The main components other than the phthalocyanine compound and the dispersion polymer contained in the photopolymerization layer are a compound capable of addition polymerization having at least one ethylenically unsaturated double bond, a photopolymerization initiator and a polymer binder, If necessary, various compounds such as a thermal polymerization inhibitor and a plasticizer can be contained.

The compound capable of addition polymerization containing an ethylenically unsaturated double bond can be arbitrarily selected from compounds having at least one, and preferably two or more, terminal ethylenically unsaturated bonds. These compounds include:
For example, those having a chemical form such as a monomer, a prepolymer such as a dimer or a trimer, and an oligomer, or a mixture thereof are included. Examples of these include esters of unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) with aliphatic polyhydric alcohol compounds, and those unsaturated carboxylic acids. An amide with an aliphatic polyamine compound is exemplified.

Specific examples of the ester monomer of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include acrylates such as ethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3.
-Butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate , So Bi penta acrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

Examples of the methacrylate include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloxy-2-hi Rokishipuropokishi) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane, and the like.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
Examples thereof include 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, and sorbitol tetritaconate. The crotonic acid ester includes ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, sorbitol tetradicrotonate and the like. As isocrotonic acid esters, ethylene glycol diisocrotonate, pentaerythritol diisocrotonate,
And sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, sorbitol tetramaleate and the like. Furthermore, a mixture of the above-mentioned ester monomers can also be mentioned. Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis -Methacrylamide, diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide and the like.

As another example, see JP-B-48-417.
08 polyisocyanate compound having two or more isocyanate groups in one molecule described in
A vinyl urethane compound having two or more polymerizable vinyl groups in one molecule to which a hydroxyl group-containing vinyl monomer represented by the following general formula (A) is added is exemplified.

General formula CH ₂ C (R) COOCH ₂ CH (R) OH (A) (where R and R ′ are each independently H or CH ₃
Is shown. )

Further, urethane acrylates described in JP-A-51-37193,
Polyester acrylates described in JP-A-8-64183, JP-B-49-43191 and JP-B-52-30490, and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid. And polyfunctional acrylates and methacrylates. In addition, Japan Adhesion Association magazine vol.20,
No. 7, pages 300 to 308 (1984) can also be used as photocurable monomers and oligomers. In addition, the use amount of these is 5 to 70% by weight (hereinafter abbreviated as%) based on the total solid content, and preferably 10 to 50%.

As the photopolymerization initiator, various photopolymerization initiators known in patents and literatures, or a combination system of two or more photopolymerization initiators (photoinitiation system) may be used depending on the wavelength of the light source used. It can be appropriately selected and used. For example, 40
When ultraviolet light of 0 nm or less is used as a light source, benzyl,
Benzoin ether, Michler's ketone, anthraquinone, acridine, phenazine, benzophenone and the like are widely used.

Various photo-initiating systems have also been proposed when using visible light of 400 nm or less, an argon laser, or a YAG-SHG laser as a light source, for example, as described in US Pat. No. 2,850,445. Certain photosensitive dyes, dye-amine complex initiation systems (JP-B-44-2018)
No. 9), a combination system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No. 45-37377), and a system of hexaarylbiimidazole and p-dialkylaminobenzylidene ketone (Japanese Patent Publication No. 47-2528).
JP-A-54-155292), a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-8
No. 4183), a system of a cyclic triazine and a merocyanine dye (Japanese Patent Application Laid-Open No. 54-115024), and a system of 3-ketocoumarin and an activator (Japanese Patent Application Laid-Open Nos. 52-112681 and 58-15503). , Biimidazole, styrene derivative, thiol (JP-A-59-14)
No. 0203), a system of an organic peroxide and a dye (JP-A-5
9-140203, JP-A-59-189340), a system of a dye having a rhodanine skeleton and a radical generator (JP-A-2-244050), titanocene and 3-
A ketocoumarin dye system (JP-A-63-221110), a system combining titanocene and a xanthene dye and an addition-polymerizable ethylenically unsaturated compound containing an amino group or a urethane group (JP-A-4-221958, JP-A-4-219756), a system of titanocene and a specific merocyanine dye (JP-A-6-295061), and the like. These photopolymerization initiators are used in an amount of 0.05 to 100 parts by weight, preferably 0.1 to 70 parts by weight, per 100 parts by weight of the ethylenically unsaturated compound.
It can be used in an amount of 0.2 parts by weight, more preferably 0.2 to 50 parts by weight.

The photopolymerizable layer of the lithographic printing plate precursor according to the present invention comprises:
Usually, a linear organic high molecular polymer is contained as a binder. Such a linear organic high molecular polymer includes a linear organic high molecular compound having compatibility with a photopolymerizable ethylenically unsaturated compound. Any one may be used as long as it is a molecular polymer. Preferably, a water- or weakly alkaline water-soluble or swellable linear organic high molecular polymer that enables water development or weakly alkaline water development is selected. The linear organic high molecular polymer is used not only as a film forming agent of the composition,
Water, weakly alkaline water or an organic solvent is selected and used depending on the use as a developer. For example, when a water-soluble organic high molecular polymer is used, water development becomes possible. Examples of such a linear organic polymer include addition polymers having a carboxylic acid group in a side chain, for example, JP-A-59-44615, JP-B-54-34327, and JP-B-58-12577. JP-B-54-25957 and JP-A-54-92.
723, JP-A-59-53836 and JP-A-59-71048, that is, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid There are copolymers, maleic acid copolymers, partially esterified maleic acid copolymers and the like.

Similarly, there are acidic cellulose derivatives having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group are useful. In particular, among these, [benzyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomers] copolymer and [allyl (meth) acrylate / (meth) acrylic acid / optionally And other addition-polymerizable vinyl monomers] copolymers.
In addition, polyvinyl pyrrolidone and polyethylene oxide are useful as the water-soluble linear organic polymer. In order to increase the strength of the cured film, an alcohol-soluble polyamide, a polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful. These linear organic high molecular polymers can be mixed in any amount with the total solid content. However, if it exceeds 90% by weight, no favorable result is obtained in view of the strength of the formed image and the like. Preferably it is 30 to 85%. The weight ratio of the photopolymerizable ethylenically unsaturated compound and the linear organic high molecular polymer is preferably in the range of 1/9 to 7/3. A more preferred range is 2/8 to 6/4.

In the present invention, in addition to the above basic components, a small amount of thermal polymerization inhibitor is used to prevent unnecessary thermal polymerization of a polymerizable ethylenically unsaturated compound during production or storage of a lithographic printing plate precursor. It is desirable to add an agent. Suitable thermal polymerization inhibitors include hydroquinone, p-
Methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl −
6-t-butylphenol), N-nitrosophenylhydroxylamine cerium salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% to about 5% based on the weight of the total solid content of the photopolymerization layer. Also, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition by oxygen,
It may be unevenly distributed on the surface of the photopolymerization layer in the process of drying after coating. The added amount of the higher fatty acid derivative is preferably about 0.5% to about 10% of the total composition of the photopolymerizable layer.

In addition, additives such as an inorganic filler and a plasticizer such as dioctyl phthalate, dimethyl phthalate and tricresyl phosphate may be added to improve the physical properties of the cured film. The addition amount of these is preferably 10% or less of the total solid content of the photopolymerization layer.

The photopolymerizable layer of the lithographic printing plate precursor according to the present invention comprises:
It is usually used by coating on a support. When coating on a support, various organic solvents can be used. As the organic solvent used here, acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether,
Propylene glycol monomethyl ether, propylene glycol monoethyl ether, acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxy Ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N N- dimethylformamide, dimethyl sulfoxide, .gamma.-butyrolactone, methyl lactate and ethyl lactate. These solvents can be used alone or as a mixture. The concentration of the solid content in the coating solution of the photopolymerization layer is preferably 2 to 50% by weight.

A surfactant can be added to the photopolymerization layer of the lithographic printing plate precursor according to the invention in order to improve the coated surface quality. Further, in the planographic printing plate precursor of the present invention, the coating amount of the photopolymerizable layer to the support on the range of about 0.1 g / m ² ~ about 10 g / m ² in weight after drying is preferable,
0.5-5 g / m < ² > is more preferable.

As the support, a dimensionally stable plate having a hydrophilic surface is used. Examples of the dimensionally stable plate include paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), and metal such as aluminum (including aluminum alloy), zinc, copper, etc. Board, and
For example, a plastic film such as cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc., and a metal as described above are laminated. Alternatively, there may be mentioned deposited paper or plastic film. Among these supports, the aluminum plate is particularly preferred because it is extremely dimensionally stable, has a hydrophilic surface, and is inexpensive. Furthermore, Japanese Patent Publication No. 48-1832
No. 7, a composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in JP-A-7 is also preferable.

In the case of a support having a metal surface, particularly an aluminum surface, a graining treatment, a dipping treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like, or an anodic oxidation treatment, etc. It is preferable that a surface treatment has been performed. Further, an aluminum plate which is grained and then immersed in an aqueous solution of sodium silicate can be preferably used. As described in JP-B-47-5125, an aluminum plate which is anodized and then immersed in an aqueous solution of an alkali metal silicate is preferably used. The anodic oxidation treatment, for example, phosphoric acid, chromic acid, sulfuric acid, inorganic acids such as boric acid, or oxalic acid, organic acids such as sulfamic acid or a salt thereof aqueous solution or non-aqueous solution alone or in combination of two or more This is carried out by flowing a current in an electrolytic solution using an aluminum plate as an anode.

Also, silicate electrodeposition as described in US Pat. No. 3,658,662 is effective. Further, Japanese Patent Publication No. 46-27481,
JP-A-58602, a support provided with electrolytic grains as disclosed in JP-A-52-30503,
A support that has been subjected to a surface treatment combining the above-described anodizing treatment and sodium silicate treatment is also useful.

Further, mechanical roughening, chemical etching, and the like disclosed in JP-A-56-28893.
It is also preferable to sequentially perform electrolytic graining, anodizing treatment, and sodium silicate treatment. Furthermore, after performing these treatments, a water-soluble resin such as polyvinylphosphonic acid, a polymer and a copolymer having a sulfonic acid group in a side chain, polyacrylic acid, a water-soluble metal salt (eg, zinc borate) or Also, those coated with a yellow dye, an amine salt or the like are suitable. Further, a sol-gel treated substrate having a functional group capable of causing an addition reaction by a radical covalently disclosed in JP-A-5-304358 is also preferably used.

These hydrophilic treatments are performed not only to make the surface of the support hydrophilic, but also to prevent harmful reactions in the photopolymer layer provided thereon and to improve the adhesiveness of the photopolymer layer. It is performed for the purpose of improving the quality.

The lithographic printing plate precursor according to the invention is usually provided with a protective layer on the photopolymerizable layer, since the exposure is usually carried out in the air. The protective layer prevents low-molecular compounds such as oxygen and basic substances present in the atmosphere, which inhibit the image forming reaction caused by exposure in the photopolymer layer, from being mixed into the photopolymer layer. Make it possible. Therefore, the desired property of such a protective layer is that the permeability of low-molecular compounds such as oxygen is low, and further, the transmission of light used for exposure is not substantially inhibited, and the adhesion to the photopolymerization layer is improved. It is desirable that it be excellent and be easily removed in a developing process after exposure. Such a device for the protective layer has been devised conventionally, and is disclosed in U.S. Pat.
No. 49729.

Examples of materials that can be used for the protective layer include:
Relatively, it is preferable to use a water-soluble polymer compound having excellent crystallinity. Specifically, water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid are used. Although it is known, use of polyvinyl alcohol as the main component gives the best results in terms of basic characteristics such as oxygen barrier properties and development removability. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether or an acetal as long as it contains an unsubstituted vinyl alcohol unit for obtaining necessary oxygen barrier properties and water solubility. Similarly, a part thereof may have another copolymer component. Specific examples of polyvinyl alcohol include those having a hydrolysis of 71 to 100% and a molecular weight of 300 to 2,400.

Specifically, PVA- manufactured by Kuraray Co., Ltd.
105, PVA-110, PVA-117, PVA-1
17H, PVA-120, PVA-124, PVA-1
24H, PVA-CS, PVA-CST, PVA-H
C, PVA-203, PVA-204, PVA-20
5, PVA-210, PVA-217, PVA-22
0, PVA-224, PVA-217EE, PVA-2
17E, PVA-220E, PVA-224E, PVA
-405, PVA-420, PVA-613, L-8 and the like. The method of applying such a protective layer is described in, for example, U.S. Pat. No. 3,458,311;
No. 49729.

The lithographic printing plate precursor thus obtained is Ar
After direct exposure with a laser or a YAG-SHG laser, development processing can be performed. In addition, through the transparent original picture, carbon arc lamp, mercury lamp, metal halide lamp,
After exposure with an actinic ray using a xenon lamp, a tungsten lamp or the like as a light source, development processing can also be performed. As a developing solution used for such a developing process, a conventionally known alkaline aqueous solution can be used. For example,
Sodium silicate, potassium, tribasic sodium, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, ammonium, And inorganic alkali agents such as sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium.

Further, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine Organic alkaline agents such as isopropanolamine, ethyleneamine, ethylenediamine, pyridine and the like are also used.

These alkali agents are used alone or in combination of two or more. Among the above-mentioned alkaline aqueous solutions, the developing solution exhibiting a further effect is an aqueous solution containing an alkali metal silicate and having a pH of 12 or more. The aqueous solution of the alkali metal silicate depends on the ratio (generally represented by the molar ratio of [SiO ₂ ] / [M ₂ O]) of silicon oxide SiO ₂ and the alkali metal oxide M ₂ O, which are the components of the silicate, and the concentration. It is possible to adjust the developing property.
SiO ₂ / N as disclosed in US Pat.
The molar ratio of a ₂ O is 1.0 to 1.5 (that is, [SiO ₂ ] /
[Na ₂ O] is 1.0 to 1.5, and the content of SiO ₂ is 1 to 4% by weight, and an aqueous solution of sodium silicate, such as described in JP-B-57-7427. , [S
iO ₂ ] / [M] is 0.5 to 0.75 (that is, [SiO ₂ ]
/ [M ₂ O] is 1.0 to 1.5), the concentration of SiO ₂ is 1 to 4% by weight, and the developer is based on gram atoms of all alkali metals present therein. Alkali metal silicates containing at least 20% potassium are preferably used.

In general, when developing a lithographic printing plate precursor using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than the developing solution is added to the developing solution so that the developing tank can be kept in the developing tank for a long time. It is known that a large amount of a lithographic printing plate precursor can be processed without replacing the developer. This replenishment system is preferably applied also when the lithographic printing plate precursor of the invention is used. For example,
The molar ratio of SiO ₂ / Na ₂ O of developer as disclosed in JP-54-62004 Patent Publication No. 1.0-1.5
(Ie, [SiO ₂ ] / [Na ₂ O] is 1.0 to 1.5), and an aqueous solution of sodium silicate having a SiO ₂ content of 1 to 4% by weight is used. continuously or intermittently molar ratio of SiO ₂ / Na ₂ O 0.5 to 1.5 in accordance with the processing amount of use precursor (that is, [SiO _2] / [Na
_{How 2} O] is added aqueous sodium silicate solution of 0.5 to 1.5) to (replenisher) in the developer, and further, JP-B-57
[SiO ₂ ] /
[M] is 0.5 to 0.75 (that is, [SiO ₂ ] / [M ₂
O] is 1.0 to 1.5) and the concentration of SiO ₂ is 1
４4% by weight of an alkali metal silicate developing solution, and the alkali metal silicate [Si
O ₂ ] / [M] is 0.25 to 0.75 (that is, [SiO ₂ ]
/ [M ₂ O] is 0.5 to 1.5), and at least 20% potassium based on the total alkali metal gram atoms both are present therein of the developing solution and the replenisher Is preferably used.

The lithographic printing plate precursor thus developed is described in JP-A-54-8002 and JP-A-55-115.
As described in JP-A Nos. 045 and 59-58431, post-treatment with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. Is done. In the post-treatment of the lithographic printing plate precursor according to the invention, these treatments can be used in various combinations. The lithographic printing plate obtained by such a process is set on an offset printing machine and used for printing a large number of sheets. As a plate cleaner used for removing stains on the plate at the time of printing, a conventionally known plate cleaner for PS plate is used. For example, CL-1 and CL-
2, CP, CN-4, CN, CG-1, PC-1, S
R, IC (manufactured by Fuji Photo Film Co., Ltd.) and the like. Preferably, CP and CN-4 are mentioned.

[0052]

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

[Examples 1 to 6] An aluminum plate of material 1S having a thickness of 0.30 mm was grained with a No. 8 nylon brush and a 400-mesh water-based suspension of pumicestone, and the surface thereof was roughened with water. Washed. After being immersed in 10% sodium hydroxide at 70 ° C. for 60 seconds for etching, washed with running water, neutralized and washed with 20% nitric acid, and then washed with water.
This was converted to 160 coulombs / dm ^{2 in} a 1% nitric acid aqueous solution using a sinusoidal alternating waveform current under the condition of V _A = 12.7 V.
The electrolytic surface roughening treatment was performed with the amount of electricity at the time of anode. When the surface assembly was measured, it was 0.6 μm (Ra display). Subsequently, it is immersed in a 30% sulfuric acid aqueous solution,
After desmutting for 2 minutes in a 20% sulfuric acid aqueous solution, the cathode was placed on the grained surface, and the current density was 2 A / dm ^2.
Anodized for 50 seconds at a thickness of 2.7 g /
m ² . A high-sensitivity photopolymerizable composition having the following composition was applied on the thus treated aluminum plate so that the dry coating weight was 1.4 g / m ^2, and dried at 100 ° C. for 1 minute to form a photopolymerizable layer. Formed.

[Photopolymerizable composition] Addition polymerizable compound 1.5 g (glycerin dimethacrylate hexamethylene diisocyanate urethane polymer (manufactured by Kyoeisha Chemical Co., Ltd .; UA101H)) Binder polymer 2.0 g (allyl methacrylate / methacrylic) Acid / N-isopropyl acrylamide (copolymerization molar ratio 67/13/20), acid value measured by NaOH titration 1.15 meq / g, weight average molecular weight 130,000 determined by GPC titration) Sensitizing dye (compound described below) 1) 0.2 g Photoinitiator (Compound 2 described below) 0.4 g Co-sensitizer (Compound 3 described below) 0.4 g Thermal polymerization inhibitor (N-nitrosophenyl 0.01 g Hydroxylamine aluminum) Salt) Surfactant (manufactured by Dainippon Ink and Chemicals, Inc., 0.02 g Megafax F-177) Methyl ethyl ketone 20.0 g Polypropylene glycol monomethyl ether 20.0 g Color pigment dispersion 2.0 g

[0055]

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(Composition of Colored Pigment Dispersion) Pigment Blue 15: 6 15 parts by weight Dispersion polymer of Table 1 10 parts by weight Cyclohexanone 15 parts by weight methoxypropyl acetate 20 parts by weight Propylene glycol monomethyl ether 40 parts by weight

A 3% by weight aqueous solution of polyvinyl alcohol (degree of saponification: 98 mol%, degree of polymerization: 500) was applied onto the photopolymerized layer so that the dry coating weight was 2.5 g / m ² , After drying for 3 minutes, a lithographic printing plate precursor was obtained. These plates were exposed to 1 to 99% halftone dots and solid images in 1% increments under the conditions of 200 μJ / cm ² , 2540 dpi, 175 lines / inch using Gutenberg (SHG-YAG laser 75 mW, 532 nm) manufactured by Heidelberg. .

The exposed lithographic printing plate precursor was developed under the following conditions. First, a developer (1) or a developer (2) shown below and a finisher FP manufactured by Fuji Photo Film Co., Ltd. were added to an automatic developing machine LP850P manufactured by Fuji Photo Film Co., Ltd.
-2 W each, developer temperature 30 ° C., development time 1
The development processing was performed under the condition of 8 seconds.

[Developer (1) (pH 11.5)] Potassium hydroxide 0.1 g Compound of the following formula 1 4.0 g Compound of the following formula 2 0.2 g 95.7 g of water

[Developer (2) (pH 12.8)] 1K potassium silicate 3.0 g potassium hydroxide 1.5 g compound of the following formula 2 0.2 g compound of the following formula 3 1.0 g 94.3 g of water

[0061]

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(Printing durability test) The lithographic printing plate obtained after the development described above was used as a printing machine with R201 manufactured by Roland as a printing machine, and GEOS-G manufactured by Dainippon Ink and Chemicals as the ink.
Printed using (N). The printing portion of the solid image was observed, and the printing durability was determined based on the number of sheets at which the image began to fade. It is assumed that the larger the number, the better the printing durability. The results are shown in Table 1 below. (Precipitation in developer (developing waste)) Dissolve an amount of the photopolymerizable composition in an amount of 10 m ² (1.4 g / m ² ) as a lithographic printing plate precursor in 1 liter of the developer. Including
After standing for one month, the amount of precipitate in the developer was observed. The results are shown in Table 1 below.

(Comparative Examples 1-2) A lithographic printing plate precursor was obtained in the same manner as in Example 1. However, the dispersion polymer in the composition of the color pigment dispersion was not used in the photopolymerizable composition (Comparative Example 1), and a conventional allyl methacrylate / methacrylic acid copolymer (Table 1) was used as the dispersion polymer.
(P4 of Example 1) was used (Comparative Example 2). The resulting lithographic printing plate precursor was exposed to light and developed in the same manner as in Example 1 to form a lithographic printing plate, and printed in the same manner as in Example 1 to perform a printing durability test. In the same manner as in Example 1, precipitation (developed residue) in the developer was observed. The results are shown in Table 1 below.

[0064]

[Table 1]

[0065]

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From the results shown in Table 1, the lithographic printing plate precursors of Examples 1 to 6 did not cause precipitation in the developing solution and had good printing durability of 120,000 to 140,000. . On the other hand, in Comparative Examples 1 and 2, precipitation occurred in the developer, which was an unsatisfactory result.

[0067]

The lithographic printing plate precursor according to the present invention comprises, as a colorant contained in the photopolymerizable layer, one of the structures represented by the general formula (1) and the structure represented by the general formula (2). By using the phthalocyanine pigment dispersed by using a polymer having at least one of the side chains, the phthalocyanine pigment is accumulated in the developer, and it is possible to prevent the development residue generated by aggregation and sedimentation, and also the printing durability. An excellent lithographic printing plate precursor can be provided.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2H025 AA04 AA12 AB03 AC08 AD01 BC13 BC31 CA00 CC12 2H096 AA06 BA05 EA04 2H114 AA04 AA23 BA01 BA10 DA21 DA52 DA53 EA02 EA03

Claims (1)

[Claims] 1. A lithographic printing plate precursor having a photopolymerization layer containing a polymer-dispersed phthalocyanine pigment having a group represented by the following general formula (1) or (2) in a side chain. Embedded image (In the formula, R represents a hydrocarbon group having 1 to 30 carbon atoms, Y represents a linking group to a polymer main chain skeleton, and Ar represents a heteroaryl group containing a nitrogen atom.)