JP2002307854A - Original plate for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for a lithographic printing plate, which has favorable on-machine developing properties, and in addition, has a high sensitivity, and of which the printing durability is favorable. SOLUTION: This original plate for a lithographic printing plate has an image-forming layer on a hydrophilic supporting body. In this case, the image- forming layer contains (A) at least one component which is selected from micro- capsules encapsuling hydrophobic particles and hydrophobic compounds, (B) a polymerization starter which is selected from borate based compounds and triazine based compounds, (C) a photothermal conversion agent, and (D) a compound having a radical polymeric group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lithographic printing plate precursor. More specifically, the present invention relates to a lithographic printing plate precursor capable of performing plate making by scanning exposure and on-press development based on digital signals and obtaining excellent printing durability.

[0002]

2. Description of the Related Art Numerous studies have been made on printing plates for computer-to-plate systems, which have been remarkably advanced in recent years. Among them, with the aim of further streamlining the process and solving the problem of waste liquid treatment, lithographic printing plate precursors that can be directly mounted on a printing machine and printed without being developed after exposure have been studied, and various methods have been studied. Proposed.

[0003] One of the methods for eliminating the processing step is to mount an exposed lithographic printing plate precursor on a cylinder of a printing press, and supply a dampening solution and ink while rotating the cylinder. There is a method called on-press development for removing a non-image portion. That is, after exposing the printing master,
It is a system that is mounted on a printing machine as it is and the processing is completed in the normal printing process. A lithographic printing plate precursor suitable for such on-press development has a photosensitive layer (heat-sensitive layer) soluble in fountain solution and ink solvent, and is further developed on a printing machine placed in a bright room. It is necessary to have a light room handling property suitable for use.

[0004] For example, Japanese Patent No. 2938397 discloses a lithographic printing plate precursor in which a photosensitive layer in which fine particles of a thermoplastic hydrophobic polymer are dispersed in a hydrophilic binder polymer is provided on a hydrophilic support. ing. According to this publication, in the lithographic printing plate precursor, after forming an image by exposing the particles of the thermoplastic hydrophobic polymer by heat with infrared laser exposure, mounting the plate on a printing press cylinder, dampening water and And / or on-press development with ink. Further, since the lithographic printing plate precursor has a photosensitive region in the infrared region, it is also suitable for handling in a bright room.

Further, Japanese Patent Application Laid-Open No. 9-127683 and WO 9
Japanese Patent Application Laid-Open No. 9-10186 also describes that a printing plate is produced by on-press development after combining thermoplastic fine particles by heat. However, although the above-described method of forming an image by the simple coalescence of fine particles by heat shows good on-press developability, there is a problem that printing durability is insufficient due to low image intensity.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, that is, a lithographic plate which maintains good on-press developability, and has high sensitivity and good printing durability. The purpose is to provide an original plate for printing plates.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result, by adopting the following constitution, the disadvantages of the prior art have been overcome, and the on-press development property has been improved. And a lithographic printing plate precursor with excellent image strength. That is, the present invention provides (A)
At least one component selected from hydrophobic particles and microcapsules containing a hydrophobic compound, (B) a polymerization initiator selected from a borate-based compound and a triazine-based compound, (C) a photothermal conversion agent, and (D) a radical A lithographic printing plate precursor comprising an image forming layer containing a compound having a polymerizable group.

The lithographic printing plate precursor according to the present invention can form an image by scanning exposure based on a digital signal. The exposure causes the hydrophobic particles contained in the image forming layer to be at least partially fused, or the hydrophobic substance is released from the inside of the microcapsule, thereby rendering the image forming layer hydrophobic. At the same time, the compound having a radical polymerizable group is cross-linked by radicals generated from the polymerization initiator,
A strong film is formed on the image area. This improves the film strength of the image area without impairing the on-press developability. From the above results, it is possible to obtain a lithographic printing plate precursor having excellent on-press developability and excellent sensitivity and printing durability.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The lithographic printing plate precursor according to the present invention will be described in detail below. [Image Forming Layer] The lithographic printing plate precursor according to the invention is, as described above, a substrate having a hydrophilic surface (abbreviated as hydrophilic support).
Above, at least one component selected from (A) microcapsules containing hydrophobic particles and a hydrophobic compound,
It is formed by applying a coating liquid of a composition containing (B) a polymerization initiator selected from a borate compound and a triazine compound, (C) a photothermal conversion agent, and (D) a compound having a radical polymerizable group. Image forming layer. First, each component of the image forming layer, which is a characteristic part of the lithographic printing plate precursor according to the invention, will be described.

(A) Microcapsules encapsulating hydrophobic particles and a hydrophobic compound (hydrophobic particles) The hydrophobic particles of the present invention are those provided as a particulate aqueous dispersion in an image forming layer. . The image forming layer contains a hydrophobic compound that is melted or softened by heat, and at least partially fuses the hydrophobic particles by heat generation by laser irradiation, thereby rendering the image forming layer more hydrophobic than the non-irradiated portion. Low molecular weight compounds as hydrophobic compounds,
Any of wax, oligomer and polymer can be used.

These hydrophobic particles can be obtained, for example, by adding a hydrophobic compound to an aqueous solution containing a dispersing agent and finely pulverizing the mixture with a milling machine such as a paint shaker or a dyno mill, or by dissolving in a water-insoluble solvent. It can also be obtained by mixing and emulsifying this with an aqueous solution containing a dispersant, further evaporating the organic solvent, solidifying it into fine particles while evaporating it, and further evaporating the polymerizable monomer into particles during polymerization, such as emulsion polymerization. Can, but is not limited to.

When a hydrophobic polymer is used, a known thermoplastic polymer or thermosetting polymer that can be made into particles can be used. The molecular weight of the polymer is preferably 3000 to 1,000,000. The thermoplastic fine particle polymer suitable for the present invention includes Research Disclosure N of January 1992.
o.33303, JP-A-9-12387, and 9-
131850, 9-171249, 9
Suitable examples include thermoplastic fine particle polymers described in JP-A-171250 and EP931647. Specific examples include homopolymers or copolymers of monomers such as ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, and mixtures thereof. Can be.

Examples of the thermosetting polymer suitable for the present invention include resins having a phenol skeleton, urea-based resins (for example, urea derivatives such as urea or methoxymethylated urea resinified with aldehydes such as formaldehyde), melamine. Resin (for example, melamine or a derivative thereof resinified with an aldehyde such as formaldehyde), an alkyd resin, an unsaturated polyester resin,
Examples thereof include a polyurethane resin and an epoxy resin.

Suitable resins having a phenol skeleton include, for example, phenol resins obtained by resinifying phenol, cresol and the like with aldehydes such as formaldehyde, hydroxystyrene resins, and phenol skeletons such as N- (p-hydroxyphenyl) methacrylamide. A methacrylamide or acrylamide resin having
A methacrylate or acrylate resin having a phenol skeleton such as -hydroxyphenyl methacrylate; In the above-mentioned hydrophobic polymer,
Further, a polymer having a polymerizable group in the molecule is preferable,
Particularly, those having a vinyl group, a (meth) acryloyl group, a styryl group, a 1-propenyl group, an isopropenyl group, a butenyl group, a vinylene group, an allyl group, or the like in a side chain are preferable.

(Microcapsules encapsulating a hydrophobic compound) As a method of microencapsulating a hydrophobic compound, a known method can be applied. For example, as a method for producing microcapsules, U.S. Patent No. 2,800,457, a method using coacervation found in No. 2,800,458, British Patent No. 990443, U.S. Patent No. 3,287,154, Japanese Patent Publication No. 38-19574,
Nos. 42-446 and 42-711, a method by an interfacial polymerization method found in U.S. Pat.No. 3,418,250, a method by polymer precipitation found in U.S. Pat.No. 3,660,304, and using an isocyanate polyol wall material found in U.S. Pat. Method, US Patent
No. 3914511, a method using an isocyanate wall material, U.S. Pat. Melamine-formaldehyde resin, a method using a wall material such as hydroxycellulose, Japanese Patent Publication Nos. 36-9163, 51-9079, in situ method by monomer polymerization, British Patent No. 930422, and US Patent No. 3111407. Examples include, but are not limited to, the spray drying method and the electrolytic dispersion cooling method found in British Patent Nos. 952807 and 967074.

The preferred microcapsule wall used in the present invention has three-dimensional crosslinks and has a property of swelling with a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane.

In the microcapsule of the present invention, at the time of its synthesis, a solvent capable of dissolving the inclusions and swelling the wall material can be added to the dispersion medium. This solvent promotes diffusion of the encapsulated compound out of the microcapsules. Such a solvent depends on the microcapsule dispersion medium, the material, wall thickness, and inclusions of the microcapsule wall, but can be easily selected from many commercially available solvents. For example, in the case of a water-dispersible microcapsule comprising a crosslinked polyurea or polyurethane wall, alcohols, ethers, acetals, esters, ketones, polyhydric alcohols, amides, amines, fatty acids and the like are preferable.

Specific compounds include methanol, ethanol, tertiary butanol, n-propanol, tetrahydrofuran, methyl lactate, ethyl lactate, methyl ethyl ketone, propylene glycol monomethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, γ-butyl lactone. , N, N-dimethylformamide, N, N-dimethylacetamide, etc., but are not limited thereto. Two or more of these solvents may be used. Solvents that do not dissolve in the microcapsule dispersion but can be dissolved by mixing the above solvents can also be used. The amount of addition is determined by the combination of materials. If the amount is less than the appropriate value, image formation becomes insufficient, and if the amount is too large, the stability of the dispersion is deteriorated. Usually, 5 to 95% by weight of the coating solution is effective, and a preferable range is 10 to 90% by weight, and a more preferable range is 15% by weight.
~ 85% by weight.

The average particle diameter of the fine particles and the microcapsules containing the hydrophobic compound is 0.01 to 3.0 μm.
However, among them, 0.05 to 2.0 μm is more preferable, and 0.08 to 1.0 μm is particularly preferable. Within this range, good resolution and stability over time can be obtained.
The addition amount of these fine particles or microcapsules is preferably 50% by weight or more of the solid content of the image forming layer, more preferably 60% by weight.
The above is more preferred. Within this range, good sensitivity and printing durability can be obtained simultaneously with good on-press developability.

(B) A polymerization initiator selected from a borate-based compound and a triazine-based compound (hereinafter, appropriately referred to as a specific polymerization initiator) The borate-based compounds suitable as the specific polymerization initiator of the present invention include: The compound represented by the formula (I) is exemplified.

[0021]

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In the formula, R ¹ , R ² , R ³ and R ⁴ each independently represent an organic group. However, R ¹ , R ² . At least one of R ³ and R ⁴ is an alkyl group. Zn ⁺ represents an n-valent cation, and n represents an integer of 1 to 6.

The general formula (I) will be described below. Examples of R ¹ , R ² , R ³ and R ⁴ include an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an alkenyl group, a substituted alkenyl group, an alkynyl group and a substituted alkynyl group, and a heterocyclic group. . However,
At least one of R ¹ , R ² , R ^S and R ⁴ is a substituted or unsubstituted alkyl group.

The alkyl group has 1 to 2 carbon atoms.
0, straight-chain, branched or cyclic alkyl groups, specific examples of which include methyl, ethyl, propyl, butyl, pentyl, hexyl,
Heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group,
Octadecyl go, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group,
Examples thereof include a cyclohexyl group, a cyclopentyl group, and a 2-norbornyl group. Among these, a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, and a cyclic alkyl group having 5 to 10 carbon atoms are more preferable.

The substituted alkyl group is constituted by a bond between a substituent and an alkylene group. As the substituent, a monovalent nonmetallic atomic group other than hydrogen is used, and a preferable example is 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-ary Rucarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N ′
An alkylureido group, an N ′, N′-dialkylureido group, an N′-arylureido group, an N ′, N′-diarylureido group, an N′-alkyl-N′-arylureido group, an N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N ′
-Alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, 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 groups, 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 (hereinafter, referred to as carboxylate), alkoxycarbonyl group,

Aryloxycarbonyl group, carbamoyl
Group, N-alkylcarbamoyl group, N, N-dialkyl
Carbamoyl group, N-arylcarbamoyl group, N, N
-Diarylcarbamoyl group, N-alkyl-N-ali
Carbamoyl group, alkylsulfinyl group, aryl
Rusulfinyl group, alkylsulfonyl group, aryls
Ruphonyl group, sulfo group (-SO_ThreeH) and its conjugate base
Group (hereinafter, referred to as sulfonato group), alkoxysulfoni
Group, aryloxysulfonyl group, sulfinamoyl
Group, N-alkylsulfinamoyl group, N, N-dial
Killsulfinamoyl group, N-arylsulfinamoy
Group, N, N-diarylsulfinamoyl group, N-A
Alkyl-N-arylsulfinamoyl group, sulfamo
Yl group, N-alkylsulfamoyl group, N, N-dia
Rukylsulfamoyl group, N-arylsulfamoyl
Group, N, N-diarylsulfamoyl group, N-alkyl
Ru-N-arylsulfamoyl group, N-acylsulfur
Amoyl group and its conjugate base group, N-alkylsulfo
Nylsulfamoyl group (—SO_TwoNHSO_Two(Alkyl))
And its conjugated base group, N-arylsulfonylsulfur
Moyl group (-SO_TwoNHSO_Two(Alkyl)) and its conjugate
Base group, N-alkylsulfonylcarbamoyl group (-C
ONHSO_Two(Alkyl)) and its conjugate base group, N-ali
Sulfonylcarbamoyl group (-CONHSO_Two(Alk
yl)) and its conjugate base group, alkoxysilyl group (—S
i (O alkyl)_Three), Aryloxysilyl group (-Si
(O alkyl)_Three), A hydroxysilyl group (—Si (O
H)_Three) And its conjugate base group, phosphono group (—PO
_ThreeH_Two) And its conjugated base group (hereinafter referred to as phosphonate group)
), A dialkylphosphono group (-PO_Three(Alkyl)_Two),
Diarylphosphono group (-PO_Three(Aryl)) _Two), Archi
Ruarylphosphono group (-PO_Three(Alkyl) (aryl)),
Monoalkylphosphono group (-PO_ThreeH (alkyl)) and its
Conjugate base group (hereinafter, referred to as alkylphosphonate group),
Monoarylphosphono group (-PO_ThreeH (aryl)) and its
Conjugate base group (hereinafter, referred to as arylphosphonate group),
Phosphonooxy group (-OPO _ThreeH_Two) And its conjugated base group
(Hereinafter referred to as phosphonatoxy group), dialkyl phos
Honoxy group (-OPO_Three(Alkyl)_Two), Diarylho
Suphonoxy group (-OPO_Three(Aryl)_Two), Alkyl ants
Olephosphonooxy group (-OPO_Three(Alkyl) (ary
l)), a monoalkylphosphonooxy group (—OPO_ThreeH
(Aryl)) and its conjugated base group (hereinafter
Natoxy group), monoarylphosphonooxy group
(-OPO_ThreeH (aryl)) and its conjugate base group (hereinafter, referred to as
Arylphosphonatooxy group), cyano group, nitro
Group, an aryl group, an alkenyl group, and an alkynyl group
Can be

In these substituents, specific examples of the alkyl group include the aforementioned alkyl groups, and specific examples of the aryl group include phenyl, biphenyl, naphthyl, tolyl, xylyl, mesityl and the like. , Cumenyl group, fluorophenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, Phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, phenoxycarbonylphenyl group, N-phenylca Ba carbamoylphenyl group, a phenyl group, nitrophenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group,
Examples include a phosphonatophenyl group. Examples of the alkenyl group include vinyl, 1-propenyl, 1-butenyl, cinnamyl, 2-chloro-
Examples thereof include a 1-ethenyl group, and examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 1-butynyl group,
Examples include a trimethylsilylethynyl group and a phenylethynyl group.

As the above acyl group (R ⁴ CO—),
R ^{4 includes a} hydrogen atom and the above-mentioned alkyl, aryl, alkenyl and alkynyl groups.

On the other hand, the alkylene group in the substituted alkyl group may be a divalent organic residue obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 20 carbon atoms. And preferably a linear alkylene group having 1 to 12 carbon atoms, a branched alkylene group having 3 to 12 carbon atoms and a cyclic alkylene group having 5 to 10 carbon atoms.

Specific examples of preferred substituted alkyl groups include chloromethyl, bromomethyl, 2-chloroethyl, trifluoromethyl, methoxymethyl, methoxyethoxyethyl, allyloxymethyl, phenoxymethyl, methylthiomethyl. Group, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group,
Benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxy Carbonylethyl group, methoxycarbonylmethyl group, methoxycarbonylbutyl group, ethoxycarbonylmethyl group,
Butoxycarbonylmethyl group,

Allyloxycarbonylmethyl, benzyloxycarbonylmethyl, methoxycarbonylphenylmethyl, trichloromethylcarbonylmethyl,
Allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- ( Sulfophenyl) carbamoylmethyl group, sulfopropyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl Group, N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group , Le phosphono hexyl group, tolyl phosphate Hona preparative hexyl, phosphono propyl group, phosphate Hona preparative oxy butyl group, benzyl group, phenethyl group, alpha-
Methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group,
Examples thereof include a 1-propenylmethyl group, a 2-butenyl group, a 2-methylallyl group, a 2-methylpropenylmethyl group, a 2-propynyl group, a 2-butynyl group, a 3-butenyl group, and the following groups.

[0032]

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Examples of the aryl group include a group in which one to three benzene rings form a condensed ring, and a group in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. Group, naphthyl group, anthryl group, phenanthryl group, indenyl group, acenabutenyl group,
Examples thereof include a fluorenyl group and the like, and among these, a phenyl group and a naphthyl group are more preferable.

The substituted aryl group is a group in which a substituent is bonded to an aryl group, and those having a monovalent nonmetallic atomic group other than hydrogen as a substituent on a ring-forming carbon atom of the aforementioned aryl group are used. Can be Preferred examples of the substituent include the aforementioned alkyl group, substituted alkyl group, and those described above as the substituent for the substituted alkyl group.

Preferred specific examples of these substituted aryl groups are biphenyl, tolyl, xylyl, mesityl, cumenyl, chlorophenyl, bromophenyl, fluorophenyl, chloromethylphenyl,
Trifluoromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl group, phenoxyphenyl group,
Methylthiophenyl group, tolylthiophenyl group, phenylthiophenyl group, ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, acetyloxyphenyl group, henzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyl Oxyphenyl group, acetylaminophenyl group, N-methylbenzoylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group,
Allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, carbamoylphenyl group, N-
Methylcarbamoylphenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) carbamoylphenyl group, N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfa Moylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, Phosphonophenyl, phosphonatophenyl, diethylphosphonophenyl, diphenylphosphonophenyl, methylphosphonophenyl, methylphosphonatophenyl, tolylphosphonophenyl, tolylphosphonatophenyl, allyl, 1 -Propenylmethyl group, 2 Butenyl, 2-methyl-allyl phenyl group, 2-methyl propenyl phenyl group, 2-propynyl phenyl group, 2-butynyl phenyl group, and a 3-butynylphenyl group.

Examples of the alkenyl group include the same alkenyl groups as those described above for the substituent that can be introduced. A substituted alkenyl group is a substituent in which a substituent replaces and bonds to a hydrogen atom of an alkenyl group.As the substituent, the substituent in the above-mentioned substituted alkyl group is used, while the alkenyl group uses the above-mentioned alkenyl group be able to. Preferred examples of the substituted alkenyl group include those represented by the following structures.

[0037]

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Examples of the alkynyl group include the same alkynyl groups as described for the substituent that can be introduced. A substituted alkynyl group is a substituent in which a hydrogen atom of an alkynyl group is replaced and bonded,
As the substituent, the substituent in the above-mentioned substituted alkyl group is used, while the alkynyl group can be the above-mentioned alkynyl group.

The heterocyclic group is a monovalent group obtained by removing one hydrogen on the heterocyclic ring, and further removing one hydrogen from the monovalent group, and the substituent in the above-mentioned substituted alkyl group is bonded. The resulting monovalent group (substituted heterocyclic group). Preferred examples of the hetero ring include those represented by the following structures.

[0040]

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[0041]

Embedded image

[0042]

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Next, R¹And R^Two, R^TwoAnd R^ThreeAre connected to each other
An example in which a ring is formed by the following method is shown. R ¹And R^Two, R^TwoAnd R^ThreeBut
As the aliphatic ring formed by bonding to each other, a 5-membered ring, 6
And 7-membered and 8-membered aliphatic rings.
And more preferably a 5- or 6-membered aliphatic ring.
Can be These are furthermore the charcoal that makes them up
May have a substituent on the elemental atom,
The substituent on the above-mentioned substituted alkyl group may be mentioned
it can. In addition, part of the ring-constituting carbon is a hetero atom (eg,
For example, oxygen, sulfur, nitrogen, etc.)
May be. Further, a part of the aliphatic ring is an aromatic ring.
May be partially formed.

Examples of the n ⁺ cation Zn ⁺ include alkali metal ions, quaternary ammonium, pyridinium, quinolinium, diazonium, monophorinium, tetrazolium, acridinium, phosphonium, sulfonium, oxosulfonium, sulfur, oxygen,
Carbon halogenium, Cu, Ag, Hg, Pd, Fe, C
o, Sn, Mo, Cr, Ni, AS, Sc, and the like; and more preferably, quaternary ammonium.

In addition, JP-A-8-34808 and JP-A-8-1808
As described in Japanese Patent Application Laid-Open No. H08-100011 and Japanese Patent Application Laid-Open No. 8-100011, polymethine, indoline, cyanine, xanthene, oxazine, arylmethane having the above-mentioned cationic group in the molecule with respect to the aforementioned borate-based anion, A borate radical generator having infrared absorption using an infrared absorbing dye such as a triarylmethane, pyrylium dye or stearium dye as a counter cation can be used. These infrared absorbing dyes are used even if introduced as a counter cation in advance, but a borate having another counter cation is brought into contact with the infrared absorbing dye in a coating solution or a light-sensitive material, and the infrared absorbing dye is converted by salt exchange. It may be a counter cation.

Preferred specific examples of the compound represented by formula (I) [(I-1) to (I-101)] are shown below, but the present invention is not limited thereto. In addition,
In the following compounds, the exemplary compound represented by (I-38) is
Compound (I-34), tetramethylammonium methyl-
Tris (trimethylsilylmethyl) -borate and tetramethylammoniumdimethylbis (trimethylsilylmethyl) borate and tetramethylammoniumdimethylbis (trimethylsilylmethyl) borate:
It is a 10: 1 mixture.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

[Table 5]

[0052]

[Table 6]

[0053]

[Table 7]

[0054]

Embedded image Chemical formulas of ^* 1 to ^* 4 in Tables 4 and 5

Among the above borate compounds, compounds containing at least one phenyl group substituted by fluorine at the m-position are more preferred.

The triazine compound suitable as the specific polymerization initiator of the present invention is a compound represented by the general formula (II).

[0057]

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In the formula (II), X ² represents a halogen atom.
Y ² is -CX ² , -NH ₂ , -NHR ³² -NR ³² or-
Representing the OR ^32. Here, R ³² represents an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group. R ³¹ is-
CX _{2 represents} an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group or a substituted alkenyl group.

Specific examples of the triazine-based compound represented by the general formula (II) include, for example, Bull.
Chem. Soc. Japan, 42, 2924 (1969), for example, 2-phenyl 4,6-bis (trichloromethyl) -S-triazine, 2- (p-chlorophenyl) -4,6-bis ( Trichloromethyl) -S-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S -Triazine, 2- (2 ', 4'-dichlorophenyl) -4,
6-bis (trichloromethyl) -S-triazine, 2,
4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6-bis (trichloromethyl)-
S-triazine, 2-n-nonyl-4,6-bis (trichloromethyl) -S-triazine, 2- (α, α, β-
Trichloroethyl) -4,6-bis (trichloromethyl) -S-triazine and the like.

Other compounds described in British Patent 1,388,492, for example, 2-styryl-4,6-
Bis (trichloromethyl) -S-triazine, 2- (p
-Methylstyryl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxystyryl)
-4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxystyryl) -4-amino-6
JP-A-53-1 such as trichloromethyl-S-triazine
No. 33428, for example, 2- (4-methoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxy-naphth-1-yl) -4 , 6-Bis-trichloromethyl-S-
Triazine, 2- [4- (2-ethoxyethyl) -naphth-1-yl) -4,6-bis-trichloromethyl-S
-Triazine, 2- (4,7-dimethoxy-naphtho-1
-Yl) -4,6-bis-trichloromethyl-S-triazine), 2- (acenaphth-5-yl) -4,6-bis-trichloromethyl-S-triazine and the like, German Patent 3,337,024. Compounds described in the above specification, for example,
The following exemplified compounds (T-1) to (T-8) can be exemplified.

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Further, J. Org. Ch. By FC Schaefer et al.
em. 29, 1527 (1964), for example, 2-methyl-4,6-bis (tribromomethyl) -S-triazine, 2,4,6-tris (tribromomethyl) -S-triazine, , 4,6-Tris (dibromomethyl) -S
-Triazine, 2-amino-4-methyl-6-tribromomethyl-S-triazine, 2-methoxy-4-methyl-6-trichloromethyl-S-triazine and the like. Further, compounds described in JP-A-62-58241, for example, exemplified compounds (T-9) to (T-14)
And the like.

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Further, compounds described in JP-A-5-281728, for example, exemplified compounds (T-15) to (T-22)
And the like.

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(C) Photothermal Conversion Agent The image forming layer of the present invention contains a photothermal conversion agent that absorbs infrared rays and generates heat to improve sensitivity. Such a light-to-heat conversion agent may be any light-absorbing substance having an absorption band in at least a part of 700 to 1200 nm, and various pigments, dyes and metal fine particles can be used.

Examples of pigments include commercially available pigments and color index (CI) handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, 1977), and “Latest Pigment Application Technology” (CMC Publishing, 1986). And "printing ink technology" (CMC Publishing, 1984) can be used.

These pigments can be used after being subjected to a known surface treatment, if necessary, in order to improve the dispersibility in the layer to which the pigment is added. Surface treatment methods include a method of surface-coating a hydrophilic resin or a lipophilic resin, a method of attaching a surfactant, and a reactive substance (for example, silica sol, alumina sol, a silane coupling agent or an epoxy compound,
A method of bonding an isocyanate compound) to the surface of the pigment. Pigment to be added to the hydrophilic layer is easy to disperse with the water-soluble resin, and so as not to impair the hydrophilicity,
It is desirable that the surface is coated with a hydrophilic resin or silica sol. The particle size of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Particularly preferred pigments include carbon black.

Examples of the dye include commercially available dyes and literatures (eg, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, 1975, “Chemical Industry”, May 1986, “Near-Infrared Absorbing Dye”, May 1986, pp. 45-51). , "Development and Market Trend of Functional Dyes in the 90's", Chapter 2, Section 2.3 (1990), CM) or patents can be used.
Specifically, azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes,
Dyes such as carbonium dyes, quinone imine dyes, polymethine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes such as nickel thiolate complexes.

Further, for example, Japanese Patent Application Laid-Open No. Sho 58-12524
No. 6, JP-A-59-84356, JP-A-60-787
No. 87, etc .;
173696, JP-A-58-181690, methine dyes described in JP-A-58-194595, and the like;
JP-A-58-112793, JP-A-58-22479
No. 3, JP-A-59-48187, JP-A-59-739
No. 96, JP-A-60-52940, JP-A-60-63
744, etc .; squarylium dyes described in JP-A-58-112792; cyanine dyes described in British Patent 434,875; and dyes described in U.S. Pat. No. 4,756,993. And cyanine dyes described in U.S. Pat. No. 4,973,572, dyes described in JP-A-10-268512, JP-A-11-23.
No. 5,883, phthalocyanine compounds.

Further, US Pat.
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645, JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, JP-A-59-84248, and JP-A-59-84248.
No. 84249, No. 59-146063, No. 59-14
No. 6061, pyranium compounds described in JP-A-59-216146, cyanine dyes described in US Pat. No. 4,283,475, pentamethine thiopyrylium salts described in U.S. Pat. 5-70
No. 2, a pyrylium compound, Eporin III-178, Epolite III-130, manufactured by Eporin Co., Ltd.
Epolite III-125 and the like are also preferably used. Among these, a preferred dye to be added to a hydrophilic matrix such as a hydrophilic resin of the heat-sensitive layer is a water-soluble dye, and specific examples are shown below. However, the present invention is not limited to these.

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Further, it is preferable to incorporate the photothermal conversion agent in hydrophobic polymer particles or in microcapsules, since the fusion between the particles and the release of the inclusion substance are further promoted and a strong film can be formed. The light-to-heat conversion substance may be used, but a lipophilic dye is more preferable. Specific examples include the following dyes.

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The above-mentioned organic photothermal conversion agent can be added to the heat-sensitive layer up to 30% by weight. Preferably 5
The content is 25% by weight, particularly preferably 7 to 20% by weight. Within this range, good sensitivity is obtained.

In the heat-sensitive layer of the present invention, fine metal particles can be used as a light-to-heat conversion agent. Many of the metal fine particles are light-heat converting and also self-heating. Preferred metal fine particles include Si, Al, Ti, V, and C.
r, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr,
Mo, Ag, Au, Pt, Pd, Rh, In, Sn,
A simple substance or an alloy of W, Te, Pb, Ge, Re, and Sb, or fine particles of oxides and sulfides thereof are exemplified.
Among the metals constituting these metal fine particles, preferred metals have a melting point of about 100, which is easily fused by light irradiation.
Metals having an absorption in the infrared, visible or ultraviolet region below 0 ° C., such as Re, Sb, Te, Au, Ag, Cu, G
e, Pb and Sn. Particularly preferred are metal fine particles having a relatively low melting point and a relatively high absorbance to heat rays, for example, Ag, Au, Cu, Sb, Ge.
And Pb, particularly preferred elements are Ag, Au and Cu.

Further, for example, Re, Sb, Te, Au, A
g, Cu, Ge, Pb, Sn or other low-melting metal particles and self-heating metal particles such as Ti, Cr, Fe, Co, Ni, W, Ge, etc. It may be composed of a substance. Ag, Pt, Pd
It is preferable to use a combination of a metal-type micro-piece and a metal-type micro-piece having particularly large light absorption when made into the same micro-piece.

The effects of the present invention can be further exerted by subjecting the surfaces of the above-described fine particles of a simple metal and an alloy to hydrophilic treatment. Means of surface hydrophilicity is a compound that is hydrophilic and has an adsorptivity to particles, such as a surface treatment with a surfactant, or a surface treatment with a substance having a hydrophilic group that reacts with the constituent substances of the particles, A method such as providing a protective colloid hydrophilic polymer film can be used. Particularly preferred is a surface silicate treatment. For example, in the case of fine iron particles, the surface can be made sufficiently hydrophilic by a method of immersing in an aqueous solution of sodium silicate (3%) at 70 ° C. for 30 seconds. Other metal fine particles can be subjected to a surface silicate treatment in the same manner.

The size of these particles is preferably 10 μm.
m, more preferably 0.003 to 5 μm, particularly preferably 0.01 to 3 μm. Within this range, good sensitivity and resolving power can be obtained, which is preferable.

In the present invention, when these metal fine particles are used as a light-to-heat converting agent, the amount added is preferably at least 10% by weight, more preferably at least 20% by weight, particularly preferably at least 20% by weight of the solid content of the image forming layer. Used at 30% by weight or more. High sensitivity is obtained within this range, which is preferable.

(D) Compound Having a Radical Polymerizable Group The compound having a radical polymerizable group used in the present invention is encapsulated in hydrophobic particles and microcapsules, or added outside the hydrophobic particles and microcapsules. By doing so, it can be contained in the image forming layer. The compound having a radical polymerizable group used in the present invention has at least one compound.
Is a radical polymerizable compound having two ethylenically unsaturated double bonds, and is selected from compounds having at least one, and preferably two or more, terminal ethylenically unsaturated double bonds. Such compounds are widely known in the industrial field, and they can be used in the invention without any particular limitation. These include, for example, monomers, prepolymers, ie, dimers, trimers and oligomers,
Or, it has a chemical form such as a polymer or a copolymer. They may be used alone or as a mixture of two or more. When a polymer or copolymer is used, (meth)
An ethylenically unsaturated double bond such as an acryloyl group, a vinyl group or an allyl group may be introduced at the time of polymerization, or may be introduced after polymerization by utilizing a polymer reaction.

Examples of monomers and copolymers thereof include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), and esters and amides thereof. Preferably, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds and amides of unsaturated carboxylic acids and aliphatic polyamine compounds are used. Further, an unsaturated carboxylic acid ester having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group, an addition reaction product of an amide with a monofunctional or polyfunctional isocyanate, an epoxy, a monofunctional or A dehydration-condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, and further, halogen A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving group such as a group or a tosyloxy group with a monofunctional or polyfunctional alcohol, amine or thiol is also suitable.
As another example, it is also possible to use a group of compounds in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene or the like.

Specific examples of the radical polymerizable compound which is an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylates such as ethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3-butane. Diol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, , 4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, penta Risuri toll triacrylate,
Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate,
Examples include sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, and 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.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
There are 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like.

The crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like.

Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include, for example, JP-B-46-27926, JP-B-51-47334,
Aliphatic alcohol esters described in JP-A-57-196231, JP-A-59-5240 and JP-A-59-196231
No. 5,241, those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also suitably used.

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,
Examples include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide, and the like.

Examples of other preferred amide monomers include those having a cyclohexylene structure described in JP-B-54-21726. Further, urethane-based addition-polymerizable compounds produced by an addition reaction between an isocyanate and a hydroxyl group are also suitable. Specific examples of such compounds include, for example, one molecule described in JP-B-48-41708. A urethane compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a hydroxyl group-containing vinyl monomer represented by the following formula (I) to a polyisocyanate compound having two or more isocyanate groups: And the like.

Formula (I) CH ₂ ＣC (R ⁰¹ ) COOCH ₂ CH (R ⁰² ) OH (where R ⁰¹ and R ⁰² represent H or CH ₃ )

Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, and
No. 49860, No. 56-17654, No. 62
Urethane compounds having an ethylene oxide skeleton described in JP-A-39417 and JP-B-62-39418 are also suitable. Further, radical polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909, and JP-A-1-105238 may be used.

Another example is disclosed in JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
Examples thereof include polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in JP-A-490-490. Also,
JP-B-46-43946, JP-B-1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
Vinyl phosphonic acid compounds described in JP-A-2-25493 can also be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Further, the Journal of the Adhesion Society of Japan, vol. 20, no. 7, pages 300 to 308 (1984) as photocurable monomers and oligomers can also be used.

[Other Additives] (Hydrophilic Resin) The image forming layer of the present invention may contain a hydrophilic resin for the purpose of improving film properties such as on-press developability and scratch strength of the image forming layer itself. it can. As the hydrophilic resin, those having a hydrophilic group such as a hydroxy group, a carboxyl group, a phosphoric acid group, a sulfonic acid group, and an amide group are preferable.

Specific examples of the hydrophilic resin include gum arabic, casein, gelatin, starch derivatives, soya gum, hydroxypropylcellulose, methylcellulose, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl acetate
Maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids and their salts, polymethacrylic acids and their salts, hydroxyethyl methacrylate homopolymers and copolymers, hydroxyethyl acrylate homopolymers and copolymers, hydroxypropyl methacrylate homopolymers Polymers and copolymers, hydroxypropyl acrylate homopolymers and copolymers, hydroxybutyl methacrylate homopolymers and copolymers, hydroxybutyl acrylate homopolymers and copolymers, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, and at least a hydrolysis degree 60% by weight, preferably at least 80% by weight
Of polyvinyl acetate, polyvinyl formal, polyvinyl pyrrolidone, acrylamide homopolymers and copolymers, methacrylamide homopolymers and copolymers, N-methylol acrylamide homopolymers and copolymers, 2-acrylamide-
Examples thereof include homopolymers and copolymers of 2-methyl-1-propanesulfonic acid, homopolymers and copolymers of 2-methacryloyloxyethylphosphonic acid, polyallylamine, and polyethyleneimine.

The amount of the hydrophilic resin added to the heat-sensitive layer is preferably from 5 to 70%, more preferably from 5 to 40% of the solid content of the heat-sensitive layer. Within this range, good on-press developability and film strength are obtained, which is preferable.

Further, after the image formation, the heat-sensitive layer of the present invention
In order to make it easy to distinguish between the image area and the non-image area, a dye having a large absorption in the visible light region can be used as a colorant for the image. Specifically, Oil Yellow # 10
1, oil yellow # 103, oil pink # 312,
Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black B
S, Oil Black T-505 (all manufactured by Orient Chemical Industries, Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI
42000), methylene blue (CI52015) and the like.
And dyes described in JP-A-62-293247. Further, pigments such as phthalocyanine pigments, azo pigments, and titanium oxide can also be suitably used. The addition amount is preferably 0.01 to 10% by weight based on the total solid content of the heat-sensitive layer coating solution.

Furthermore, a plasticizer can be added to the heat-sensitive layer of the present invention, if necessary, to impart flexibility to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate,
Dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, and the like are used.

The heat-sensitive layer of the present invention is applied by preparing a coating solution by dissolving or dispersing the above-mentioned necessary components in a solvent.
As the solvent used here, ethylene dichloride,
Cyclohexanone, methyl ethyl ketone, methanol,
Ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-
Methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyl lactone, toluene, water and the like,
It is not limited to this. These solvents are used alone or as a mixture. The solid content concentration of the coating solution is preferably 1 to 50% by weight.

The coating amount (solid content) of the heat-sensitive layer on the support obtained after coating and drying varies depending on the application, but is generally preferably 0.5 to 5.0 g / m ² . Various methods can be used as a method of applying. For example,
Examples include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

The coating solution for the heat-sensitive layer according to the present invention may contain a surfactant for improving the coating property, for example, a surfactant described in JP-A-62-1987.
A fluorinated surfactant as described in JP 170950 can be added. The preferred addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight of the total solids of the heat-sensitive layer.

The lithographic printing plate precursor of the present invention is provided on the image forming layer in order to protect the surface of the hydrophilic image forming layer from contamination by lipophilic substances during storage and from contamination (fingerprint) due to contact with fingers during handling. May be provided with a hydrophilic overcoat layer.

The hydrophilic overcoat layer used in the present invention can be easily removed on a printing press, and is selected from a water-soluble resin or a water-swellable resin obtained by partially crosslinking a water-soluble resin. It contains.

Such a water-soluble resin is selected from a water-soluble natural polymer and a synthetic polymer, and can be used to form a film when applied and dried using the water-soluble resin alone or together with a crosslinking agent. Specific examples of the water-soluble resin preferably used in the present invention include, as natural polymers, gum arabic, water-soluble soybean polysaccharide, and cellulose derivatives (eg, carboxymethyl cellulose, carboxyethyl cellulose,
Methylcellulose), denatured forms thereof, white dextrin, pullulan, enzymatically degraded etherified dextrin, etc.
For synthetic polymers, polyvinyl alcohol (having a hydrolysis rate of polyvinyl acetate of 65% or more), polyacrylic acid,
Its alkali metal salt or amine salt, polyacrylic acid copolymer, its alkali metal salt or amine salt, polymethacrylic acid, its alkali metal salt or amine salt,
Vinyl alcohol / acrylic acid copolymer and its alkali metal salt or amine salt, polyacrylamide, its copolymer, polyhydroxyethyl acrylate, polyvinyl pyrrolidone, its copolymer, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer Polymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, alkali metal salt or amine salt thereof, poly-2-acrylamido-2-methyl-1-propanesulfonic acid copolymer, alkali metal salt thereof Alternatively, amine salts and the like can be mentioned. Further, according to the purpose, two or more of these resins can be used in combination. However, the invention is not limited to these examples.

When at least one or more water-soluble resins are partially cross-linked to form an overcoat layer on the hydrophilic layer, the cross-linking is carried out by a cross-linking reaction using a reactive functional group of the water-soluble resin. . The cross-linking reaction may be covalent cross-linking or ionic cross-linking.

Crosslinking decreases the tackiness of the surface of the overcoat layer and improves the handleability of the lithographic printing plate. However, if crosslinking proceeds too much, the overcoat layer changes to lipophilic, causing overcoating on a printing press. Moderate partial cross-linking is preferred because it makes removal of the layer difficult. The preferable degree of partial cross-linking is as follows: when the printing plate is immersed in water at 25 ° C., the hydrophilic overcoat layer remains without eluting in 30 seconds to 10 minutes, but elution is observed in 10 minutes or more. It is about.

Examples of the compound (crosslinking agent) used in the crosslinking reaction include known polyfunctional compounds having crosslinking properties, such as polyepoxy compounds, polyamine compounds, polyisocyanate compounds, polyalkoxysilyl compounds, titanate compounds, and the like. Aldehyde compounds, polyvalent metal salt compounds,
Hydrazine and the like.

The crosslinking agents can be used alone or as a mixture of two or more. Among the crosslinking agents, a particularly preferred crosslinking agent is a water-soluble crosslinking agent, but a water-insoluble one can be used by dispersing it in water with a dispersant.

Particularly preferred combinations of the water-soluble resin and the crosslinking agent include carboxylic acid-containing water-soluble resin / polyvalent metal compound, carboxylic acid-containing water-soluble resin / water-soluble epoxy resin, and hydroxyl group-containing resin / dialdehydes. .

The preferable addition amount of the crosslinking agent is 2
-10% by weight. Within this range, good water resistance can be obtained without impairing the removability of the overcoat layer on a printing press.

In addition, a nonionic surfactant can be mainly added to the overcoat layer in the case of aqueous solution application for the purpose of ensuring uniformity of application. Specific examples of such a nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride, polyoxyethylene nonyl phenyl ether, polyoxyethylene dodecyl ether, and the like. . The proportion of the nonionic surfactant in the total solid content of the overcoat layer is preferably 0.05 to 5% by weight, and more preferably 1 to 3% by weight.

When the water-soluble resin is not crosslinked, the thickness of the overcoat layer of the present invention is from 0.1 μm to 3.
0 μm is preferred, and a more preferred range is from 0.1 μm to 1.0 μm. When the water-soluble resin is partially crosslinked, the range is preferably 0.1 to 0.5 μm, and 0.1 to 0.3 μm.
μm is more preferred. Within this range, contamination of the hydrophilic layer by the lipophilic substance can be prevented without impairing the removability of the overcoat layer on the printing press.

In the lithographic printing plate precursor according to the present invention, the support on which the heat-sensitive layer can be applied is a dimensionally stable plate-like material such as paper, plastic (eg, polyethylene, polypropylene, polystyrene, etc.). ) Laminated paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, Polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic film on which the above-mentioned metal is laminated or vapor-deposited. Preferred supports include a polyester film or an aluminum plate.

The aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of a different element. Further, a plastic is laminated on a thin film of aluminum or an aluminum alloy. The foreign elements contained in aluminum alloys include silicon, iron, manganese, copper, magnesium, chromium, zinc,
There are bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. However, as the aluminum plate applied to the present invention, an aluminum plate of a conventionally known material can be appropriately used.

The substrate used in the present invention has a thickness of 0.05 mm to 0.6 mm, preferably 0.1 mm to 0.6 mm.
0.4 mm, particularly preferably 0.15 mm to 0.3 mm
It is.

Prior to using the aluminum plate, it is preferable to perform a surface treatment such as surface roughening and anodic oxidation. The surface treatment makes it easy to improve hydrophilicity and ensure adhesion to the heat-sensitive layer.

The surface roughening treatment of the aluminum plate surface is performed by various methods. For example, a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of chemically roughening the surface. It is carried out by a method of selective dissolution. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. As a chemical method, a method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in JP-A-54-31187 is suitable. Further, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Also, an electrolytic surface roughening method using a mixed acid as disclosed in JP-A-54-63902 can be used.

The surface roughening by the above-mentioned method is carried out when the center line average roughness (Ra) of the surface of the aluminum plate is 0.2-1.
It is preferable that the coating be performed within a range of 0 μm. The roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide or sodium hydroxide as necessary, and further neutralized, and then, if necessary, anodized to enhance abrasion resistance. Processing is performed. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used, and generally, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte. Anodizing treatment conditions vary depending on the electrolyte to be used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are appropriate. The amount of the formed oxide film is 1.0 to 5.0.
g / m ^2, it is particularly preferably 1.5 to 4.0 g / m ^2.

As the support used in the present invention, a substrate having the above-mentioned surface treatment and having an anodized film may be used as it is.
For further improvement of heat insulation, etc., if necessary,
A process for enlarging micropores of an anodized film, a process for sealing micropores, and a process for hydrophilizing a surface immersed in an aqueous solution containing a hydrophilic compound, which are described in JP-A-00-65219 and Japanese Patent Application No. 2000-14387, are appropriately performed. You can choose to do it. Suitable hydrophilic compounds for the above-mentioned hydrophilic treatment include polyvinylphosphonic acid, compounds having a sulfonic acid group, saccharide compounds, citric acid, alkali metal silicates, potassium zirconium fluoride, phosphates / inorganic fluorine compounds, and the like. Can be mentioned.

When a support having insufficient surface hydrophilicity such as a polyester film is used as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. As the hydrophilic layer, described in Japanese Patent Application No. 2000-10810,
Applying a coating liquid containing a colloid of an oxide or hydroxide of at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. The hydrophilic layer formed is preferred. Among them, a hydrophilic layer formed by applying a coating solution containing a colloid of silicon oxide or hydroxide is preferred.

In the present invention, before coating the heat-sensitive layer, if necessary, an inorganic undercoat layer such as a water-soluble metal salt such as zinc borate described in Japanese Patent Application No. 2000-143388, or For example, an organic undercoat layer containing carboxymethyl cellulose, dextrin, polyacrylic acid, or the like can be provided. The undercoat layer may contain the photothermal conversion agent.

The lithographic printing plate precursor of the present invention forms an image by heat. Specifically, direct image-like recording with a thermal recording head or the like, scanning exposure with an infrared laser, high illuminance flash exposure such as a xenon discharge lamp, infrared lamp exposure, or the like is used. Semiconductors that emit infrared light with a wavelength of 700 to 1200 nm are used. Exposure with a solid-state high-output infrared laser such as a laser or a YAG laser is preferable.

The lithographic printing plate precursor of the present invention, which has been image-exposed, can be mounted on a printing press without any further treatment, and can be printed by an ordinary procedure using ink and fountain solution.

The lithographic printing plate precursor of the present invention, which has been subjected to image exposure, can be prepared by a simple lithographic printing method using no dampening solution, for example, as described in JP-B-49-26844 and JP-B-Showa 4
9-27124, JP-B-49-27125, JP-A-53-36307, and JP-A-53-36.
No. 308, JP-B-61-52867, JP-A-58-2114844, JP-A-53-27803.
JP, JP-A-53-29807, JP-A-54-29807
146110, JP-A-57-212274, JP-A-58-37069, JP-A-54-10
Lithographic printing using the emulsion ink described in JP-A-6305 is also possible.

As described in Japanese Patent No. 2938398, these lithographic printing plate precursors are mounted on a cylinder of a printing press, then exposed by a laser mounted on the printing press, and thereafter exposed on a press. It is also possible to develop. These lithographic printing plate precursors can be used for printing after development using water or an appropriate aqueous solution as a developing solution.

[0131]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, of course, are not intended to limit the scope of the present invention. <Synthesis of Radical Polymerizable Group-Containing Polymer P-1> (Synthesis of Monomer M-1) To a solution of hydroxyethyl methacrylate: 260.3 g and 1,000 ml of tetrahydrofuran, 253.9 g of 3-chloropropionic acid chloride was dropped and reacted. Water was added to this solution, neutralized with potassium carbonate, extracted with ethyl acetate, and distilled and purified from the extract. (Yield 92%)

(Synthesis of Polymer P-1 Containing Radical Polymerizable Group) The above-mentioned synthetic monomer M-1: 68 g, methacrylic acid: 7.9 g, propylene glycol monomethyl ether: 140 ml, initiator V-65: 0.5 g Was heated to 70 ° C. while stirring under a nitrogen atmosphere, and reacted for 4 hours. After cooling, 500 ml of propylene glycol monomethyl ether was added to this solution, and 81 g of triethylamine was added and reacted for 1 hour while grinding and cutting. Further, 1.0 ml of concentrated hydrochloric acid and 100 ml of water were added dropwise to this solution. The precipitate was filtered and purified to obtain an acryloyl group-containing polymer P-1.

(Synthesis Example of Hydrophobic Particle Dispersion (1)) As the oil phase component, 1.7 g of the polymer P-1 described above, 0.31 g of an infrared absorber (IR-24 described in this specification), and a radical Generator (I-69 described in this specification): 0.3 g and 0.1 g of anionic surfactant Pionin A-41C (manufactured by Takemoto Yushi) are dissolved in 6 g of methyl ethyl ketone and 12 g of ethyl acetate, and then the aqueous phase component polyvinyl is dissolved. Alcohol (Kuraray Co., Ltd. PVA205) 0.7% aqueous solution 48
g at 10 g at 15000 rpm with a homogenizer.
It was emulsified and dispersed for minutes. Thereafter, while stirring at 400 ° C. for 3 hours, methyl ethyl ketone and ethyl acetate were evaporated. The solid content concentration of the obtained fine particle dispersion was 5.53% by weight. The average particle size was 0.30 μm.

(Synthesis Example of Hydrophobic Particle Dispersion (2)) The same formulation as in the synthesis example of Hydrophobic Particle Dispersion (1) except that the radical generator was changed from I-69 to T-1. Thereby, a hydrophobic particle dispersion liquid (2) was obtained. The solid content concentration of the obtained fine particle dispersion was 5.5% by weight. The average particle size was 0.34 μm.

(Synthesis Example of Hydrophobic Particle Dispersion Night (3)) The same formulation was used except that the radical generator in the synthesis example of the hydrophobic particle dispersion liquid (1) was changed from I-69 to T-15. Thus, a hydrophobic particle dispersion (3) was obtained. The solid content concentration of the obtained fine particle dispersion was 5.49% by weight. The average particle size was 0.32 μm.

(Synthesis Example of Hydrophobic Particle Dispersion (4)) Allyl methacrylate / methacrylic acid (copolymerization ratio 70/30, weight average molecular weight: 15,000) as an oil phase component
2 g, infrared absorbing dye (IR-24 as described herein):
0.31 g, tris (methacryloyloxyethyl) isocyanurate: 0.5 g, radical generator (I-69 described in this specification) 0.3 g, and anionic surfactant Pionin A-41C (manufactured by Takemoto Yushi) 0.1 g , 6 g of methyl ethyl ketone and 12 g of ethyl acetate, and then an aqueous phase component of polyvinyl alcohol (PVA2 manufactured by Kuraray Co., Ltd.)
05) The mixture was mixed with 48 g of a 0.7% aqueous solution, and emulsified and dispersed with a homogenizer at 15000 rpm for 10 minutes. Thereafter, while stirring at 40 ° C. for 3 hours, methyl ethyl ketone and ethyl acetate were evaporated. The solid content concentration of the obtained fine particle dispersion was 5.47%. The average particle size is 0.3
It was 5 μm.

(Synthesis Example of Hydrophobic Particle Dispersion (5)) As the oil phase component, 2 g of the polymer P-1 described above, 0.31 g of an infrared absorbent (IR-24 described in the present specification): 0.31 g, and an anionic interface Activator Pionin A-41C (manufactured by Takemoto Yushi)
0.1 g of methyl ethyl ketone 6 g and ethyl acetate 1
After dissolving in 2 g, a 0.7% aqueous solution 48 of an aqueous phase component of polyvinyl alcohol (PVA205 manufactured by Kuraray Co., Ltd.)
g at 10 g at 15000 rpm with a homogenizer.
It was emulsified and dispersed for minutes. Thereafter, while stirring at 40 ° C. for 3 hours, methyl ethyl ketone and ethyl acetate were evaporated. The solid content concentration of the obtained fine particle dispersion was 5.42% by weight. The average particle size was 0.30 μm.

(Synthesis Example of Hydrophobic Particle Dispersion (6)) 100 g of methyl methacrylate, 237 g of water, surfactant X
L-102F (4.7% aqueous solution manufactured by Lion Corporation) 10 g
Was put into a three-necked flask, and the temperature was raised to 80 ° C. while injecting nitrogen. Then, after stirring for about 30 minutes, 1 g of K ₂ S ₂ O ₈ was added.
And emulsion polymerization was carried out at 80 ° C. for 6 hours.
A polymethyl methacrylate particle dispersion having a μm of 30% solids concentration was obtained.

(Synthesis Example of Microcapsule Dispersion (1)) A 50% ethyl acetate solution of an adduct of trimethylolpropane and xylylenediisocyanate as an oil phase component (Takenate D-110N manufactured by Takeda Pharmaceutical Co., Ltd., macrocapsule wall) Material): 24 g, pentaerythritol tetraacrylate (KAYARAD A-TMM manufactured by Nippon Kayaku)
T): 17.5 g, infrared absorbing dye (I described in this specification)
R-24): 5 g, radical generator (I described in this specification)
-69): 5 g and pionin A41C: 0.1 g were dissolved in 30 g of methyl ethyl ketone and 60 g of ethyl acetate.
As the aqueous phase component, 120 g of a 4% aqueous solution of PVA205 was prepared. The oil phase component and the aqueous phase component were emulsified at 10,000 rpm for 10 minutes using a homogenizer. Thereafter, 200 g of distilled water was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The solid content concentration of the obtained microcapsule solution was 12.0% by weight, and the average particle size was 0.35 μm.

(Synthesis Example of Microcapsule Dispersion (2)) A 50% ethyl acetate solution of an adduct of trimethylolpropane and xylylene diisocyanate as an oil phase component (Takeda Pharmaceutical Industries Takenate D-110N, macrocapsule wall) Material): 24 g, dipentaerythritol hexaacrylate (KAYARAD DPHA manufactured by Nippon Kayaku):
17.5 g of an infrared absorbing dye (IR-2 described in this specification)
4) 5 g, radical generator (T-15 described in this specification)
5 g and pionin A41C: 0.1 g were dissolved in 30 g of methyl ethyl ketone and 60 g of ethyl acetate. As the aqueous phase component, 120 g of a 4% aqueous solution of PVA205 was prepared. The oil phase component and the aqueous phase component were separated using a homogenizer to 1000
The mixture was emulsified at 0 rpm for 10 minutes. Thereafter, 200 g of water was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The solid concentration of the obtained microcapsule liquid is 12.3% by weight.
And the average particle size was 0.33 μm.

(Synthesis Example of Microcapsule Dispersion Liquid (3)) A 50% ethyl acetate solution of an adduct of trimethylolpropane and xylylene diisocyanate as an oil phase component (Takenate D-110N manufactured by Takeda Pharmaceutical Co., Ltd., macrocapsule wall) Material): 24 g, dipentaerythritol hexaacrylate (KAYARAD DPHA manufactured by Nippon Kayaku) 2
2.5 g of an infrared absorbing dye (IR-2 described in this specification)
4) 5 g, pionin A41C and 0.1 g were dissolved in 30 g of methyl ethyl ketone and 60 g of ethyl acetate. As the aqueous phase component, 120 g of a 4% aqueous solution of PVA205 was prepared. The oil phase component and the aqueous phase component are separated using a homogenizer.
The mixture was emulsified at 0000 rpm for 10 minutes. Then add 200 water
g was added and the mixture was stirred at room temperature for 30 minutes and at 40 ° C. for 3 hours. 11. The solid content concentration of the obtained microcapsule liquid is 12.
4% by weight, and the average particle size was 0.30 μm.

(Synthesis Example of Microcapsule Dispersion (4)) A 50% ethyl acetate solution of an adduct of trimethylolpropane and xylylene diisocyanate as an oil phase component (Takenate D-110N manufactured by Takeda Pharmaceutical Co., Ltd., macrocapsule wall) Material): 24 g, 17.5 g of pentaerythritol tetraacrylate (A-TMMT, manufactured by Nippon Kayaku), 10 g of radical generator (I-59 described in this specification), 0.1 g of pionin A41C, and 0.1 g of methyl ethyl ketone 30
g, 60 g of ethyl acetate. PV as water phase component
120 g of a 4% aqueous solution of A205 was prepared. The oil phase component and the water phase component were separated using a homogenizer at 10,000 rpm.
For 10 minutes. Thereafter, 200 g of water was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The solid content concentration of the obtained microcapsule liquid was 12.3% by weight,
The average particle size was 0.34 μm.

(Production Example of Support) 99.5% or more of aluminum, 0.30% of Fe, 0.10% of Si,
JIS A105 containing 0.02% and 0.013% Cu
The molten alloy of alloy No. 0 was subjected to a cleaning treatment and cast. In the cleaning treatment, a degassing treatment was performed to remove unnecessary gas such as hydrogen in the molten metal, and a ceramic tube filter treatment was performed. The casting was performed by DC casting. The solidified ingot having a thickness of 500 mm was chamfered from the surface by 10 mm, and homogenized at 550 ° C. for 10 hours to prevent the intermetallic compound from becoming coarse. Next, after hot rolling at 400 ° C. and intermediate annealing in a continuous annealing furnace at 500 ° C. for 60 seconds, cold rolling was performed to obtain a rolled aluminum sheet having a sheet pressure of 0.30 mm. The center line average surface roughness Ra after cold rolling was controlled to 0.2 μm by controlling the roughness of the rolling roll. Then, it was subjected to a tension leveler to improve the flatness.

Next, a surface treatment for forming a lithographic printing plate support was performed. First, in order to remove the rolling oil on the surface of the aluminum plate, a degreasing treatment was performed with a 10% aqueous sodium aluminate solution at 50 ° C. for 30 seconds, and a 30% sulfuric acid aqueous solution was neutralized at 50 ° C. for 30 seconds, and a smut removal treatment was performed.

Then, in order to improve the adhesion between the support and the image forming layer and to provide water retention to the non-image area, a so-called graining treatment was performed to roughen the surface of the support. 1
Aqueous solution containing 4% nitric acid and 0.5% aluminum nitrate
While maintaining the temperature at 5 ° C. and flowing the aluminum web into the aqueous solution, the anode-side electric quantity 240 C / d with an alternating waveform having a current density of 20 A / dm ² and a duty ratio of 1: 1 by the indirect power supply cell.
Electrolytic graining was performed by giving m ² . Then 10
Etching was performed with a 50% aqueous solution of sodium aluminate at 50 ° C. for 30 seconds, and neutralization and smut removal were performed with a 30% aqueous solution of sulfuric acid at 50 ° C. for 30 seconds.

In order to further improve abrasion resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. An anodic oxide film of 2.5 g / m ^{2 is} obtained by performing an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power supply cell while carrying an aluminum web through the electrolyte using a 20% aqueous solution of sulfuric acid at 35 ° C. as an electrolyte. It was created. Thereafter, a silicate treatment was performed to ensure hydrophilicity as a non-image portion of the printing plate. For the treatment, a 1.5% aqueous solution of sodium silicate No. 3 was maintained at 70 ° C., passed through the aluminum web so that the contact time was 15 seconds, and further washed with water. The amount of Si attached is 10mg
/ M ² . The center line surface roughness Ra of the support (1) produced as described above was 0.25 μm.

[Examples 1 to 4] The hydrophobic particle dispersions (1) to (4) of the synthesis examples were respectively coated with a bar on the support obtained in the above production example, and were heated in an oven at 50 ° C for 120 seconds. The resultant was dried under the conditions to prepare a lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² .

Example 5 The following image forming layer coating solution (1) was prepared on the same support as that used in Example 1, applied with a bar, and heated in an oven at 50 ° C. for 120 seconds. To prepare a lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² .

[Image Forming Layer Coating Solution (1)] Hydrophobic Particle Dispersion (1) 20 g A-600 (Acrylate monomer manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.2 g Distilled water 4.0 g

Example 6 The following image forming layer coating solution (2) was prepared on the same support as that used in Example 1, applied with a bar, and heated in an oven at 50 ° C. for 120 seconds. To prepare a lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² .

[Image forming layer coating liquid (2)] Hydrophobic particle dispersion liquid (5) 20 g Radical initiator (I-87 described in this specification) 0.15 g Distilled water 3.11 g

Example 7 On the same support as used in Example 1, the following image forming layer coating solution (3) was prepared, coated with a bar, and placed in an oven at 50 ° C. for 120 seconds. After drying, a lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² was prepared.

[Image Forming Layer Coating Solution (3)] Hydrophobic Particle Dispersion (6) 1.67 g Polyacrylic acid (weight average molecular weight 25000) 4% aqueous solution 2.5 g Radical initiator (I- described in the present specification) 87) 0.15 g A-600 (acrylate monomer manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.15 g Photothermal conversion agent (IR-10 described in this specification) 0.10 g Distilled water 14.2 g

Example 8 On the same support as used in Example 1, the following image forming layer coating solution (4) was prepared, coated with a bar, and heated in an oven at 50 ° C. for 120 seconds. To prepare a lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² .

[Image Forming Layer Coating Solution (4)] Microcapsule Dispersion Solution (1) 5.0 g Propylene glycol monomethyl ether 1.1 g Distilled water 5.26 g

Example 9 Application of the image forming layer was carried out in the same manner as in Example 8, except that the microcapsule dispersion night (1) of the coating solution (4) of the image forming layer was changed to the microcapsule dispersion (2). Liquid (5) was prepared, and coated under the same coating conditions.
A lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² was prepared.

Example 10 The following image forming layer coating solution (6) was prepared on the support used in Example 1, applied to a bar, and dried in an oven at 50 ° C. for 120 seconds. A lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² was prepared.

[Image forming layer coating liquid (6)] Microcapsule dispersion liquid (3) 10 g Radical initiator (I-87 described in this specification) 0.20 g Propylene glycol monomethyl ether 2.8 g Distilled water 14 g

Example 11 The following image forming layer coating solution (7) was prepared on the support used in Example 1, applied with a bar, and dried in an oven at 50 ° C. for 120 seconds. A lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² was prepared.

[Image Forming Layer Coating Solution (7)] Microcapsule Dispersion Solution (1) 10 g Propylene glycol monomethyl ether 1.1 g Distilled water 5.26 g

[Comparative Example 1] A hydrophobic fine particle dispersion (5) was coated on the same support as the support used in Example 1 with a bar and dried in an oven at 50 ° C for 120 seconds. A lithographic printing plate precursor having a dry coating amount of the image forming layer of 0.8 g / m ² was prepared.

[Comparative Example 2] The following image forming layer coating solution (8) was prepared on the support used in Example 1, coated with a bar, and dried in an oven at 50 ° C for 120 seconds. A lithographic printing plate precursor having a dry coating amount of the forming layer of 0.8 g / m ² was prepared.

[Image Forming Layer Coating Solution (8)] Microcapsule Dispersion Solution (3) 10 g Propylene glycol monomethyl ether 2.2 g Distilled water 10.3 g

Comparative Example 3 The following image forming layer coating solution (9) was prepared on the support used in Example 1, applied with a bar, and dried in an oven at 50 ° C. for 120 seconds. A lithographic printing plate precursor having a dry coating amount of the forming layer of 0.8 g / m ² was prepared.

[Image Forming Layer Coating Solution (9)] Hydrophobic Particle Dispersion Solution (6) 16.7 g Polyacrylic acid (weight average molecular weight 25000) 4% aqueous solution 25.0 g Light-to-heat converting agent (IR- 10) 1.0 g distilled water 17.8 g

[Comparative Example 4] The following image forming layer coating solution (10) was prepared on the support used in Example 1, coated with a bar, dried in an oven at 50 ° C for 120 seconds, and dried. A lithographic printing plate precursor having a dry coating amount of the forming layer of 0.8 g / m ² was prepared.

[Image Forming Layer Coating Solution (10)] Hydrophobic Particle Dispersion Night (6) 3.34 g Polyacrylic acid (weight average molecular weight 25000) 4% aqueous solution 5 g Photothermal conversion agent (IR-10 described in this specification) 0.2 g A-600 (acrylate monomer manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.3 g distilled water 23.1 g

The thus obtained on-press developable flat plate
Water-cooled 40W infrared semiconductor laser
Equipped with the Creo Trendsetter 3244VFS
, Output 9W, outer drum rotation speed 210rpm, plate surface
Energy 100mj / cm ^Two, Resolution 2400 dpi
After exposure under the conditions of
Attached to the cylinder of the SOR-M printing machine
After supplying ink, supply ink, supply paper, and print
Printing was done. Both printing masters can be developed on-press.
I was able to print. Number of printable sheets obtained with each master
(Number of printing plates; printing durability index) was evaluated. The above image forming layer
Table 8 shows the composition and the printing durability evaluation results.

[0169]

[Table 8]

As is clear from the results shown in Table 8, the lithographic printing plate precursors of Examples 1 to 10 of the present invention had good on-press developability and excellent printing durability, and satisfactory results were obtained. The lithographic printing plate precursors of Comparative Examples 1 to 4 were unsatisfactory in terms of printing durability.

[0171]

As described above, the lithographic printing plate precursor according to the present invention can form an image by scanning exposure based on a digital signal. By the exposure, the hydrophobic particles contained in the image forming layer are at least partially fused, or the hydrophobic substance is released from the inside of the microcapsule, thereby rendering the image forming layer hydrophobic. At the same time, a compound having a radical polymerizable group is crosslinked by radicals generated from the polymerization initiator, thereby forming a strong film on the image area.
This improves the film strength of the image area without impairing the on-press developability. This has the effect of maintaining a good on-press developability and obtaining a lithographic printing plate precursor having extremely high practicality with excellent sensitivity and printing durability.

Continued on front page F term (reference) 2H025 AA01 AA12 AB03 AC08 AD01 BC13 BC42 BH02 CA28 CA39 CA48 CC11 DA10 FA10 2H096 AA06 BA05 BA20 EA04 EA23 2H114 AA04 AA22 AA24 BA01 DA47 DA48 DA49 DA52 EA03

Claims (1)

[Claims] 1. A hydrophilic support, wherein (A) at least one component selected from hydrophobic particles and a microcapsule containing a hydrophobic compound, and (B) a borate-based compound and a triazine-based compound. Polymerization initiator,
A lithographic printing plate precursor comprising: an image forming layer containing (C) a photothermal conversion agent and (D) a compound having a radical polymerizable group.