JP2005059378A - Original plate for thermosensitive lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original plate for a thermosensitive lithographic printing plate which can record an image by scan exposure and need not be treated for development with improved resistance to plate wear. <P>SOLUTION: This original plate for a thermosensitive lithographic printing plate has (1) an ink acceptance layer and (2) a hydrophilic layer containing a colloidal particle-like oxide or a colloidal particle-like hydroxide of at least one element selected from the group consisting of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and a transition metal, laminated in that order on a support. In addition, at least either of the ink acceptance layer or the hydrophilic layer contains a photothermal conversion agent. The ink acceptance layer contains a polymer having at least one functional group, in the side chain, selected from among a cationic group, a group including two carbonyl groups having one carbon atom or nitrogen atom interposed in-between and a lactone group. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a development-free lithographic printing plate precursor for a computer-to-plate (CTP) system. More specifically, image recording by infrared scanning exposure based on a digital signal is possible, and the recorded image can be directly mounted on a printing machine and printed without going through a conventional liquid development process. The present invention relates to a possible thermosensitive lithographic printing plate precursor.

  Conventionally, the production of a lithographic printing plate has been performed by a system that exposes a printing plate precursor through a lith film, which is an intermediate material. However, with the rapid progress of digitization in the printing field in recent years, the printing plate preparation process is changing to a CTP system that directly outputs digital data input to a computer and edited to a printing plate precursor. Furthermore, with the aim of further streamlining processes, development-free lithographic printing plate precursors that can be printed as they are without being developed after exposure have been developed.

  As a technology for this development-free lithographic printing plate precursor, ablation in which exposure is performed with a solid-state high-power infrared laser such as a semiconductor laser or YAG laser, heat is generated with a photothermal conversion agent that converts light into heat, and the exposed portion is decomposed and evaporated The technology using is known. That is, it is a technique in which a hydrophilic layer is provided on a support having an oleophilic ink-receiving surface or an ink-receiving layer, and the hydrophilic layer is removed by ablation.

  As a lithographic printing plate precursor that does not require development by such an ablation technique, a printing plate is known in which a crosslinked hydrophilic layer is provided on an oleophilic laser light absorbing layer and the hydrophilic layer is ablated (Patent Document 1). reference.). This hydrophilic layer is formed by cross-linking polyvinyl alcohol with a hydrolyzate of tetraethoxy silicon and containing titanium dioxide particles, and is intended to improve the film strength of the hydrophilic layer. Although the printing durability is improved by this technique, the resistance to stains is insufficient and further improvement is required.

  In addition, an ink receiving layer on a support and a lithographic printing that has a hydrophilic layer mainly composed of a colloid such as silica crosslinked with a crosslinking agent such as aminopropyltriethoxysilane and can be mounted on a printing machine without development. An original plate for printing is known (see Patent Document 2). This hydrophilic layer increases the resistance to printing stains by reducing the number of hydrocarbon groups as much as possible, and improves the printing durability by crosslinking the colloid with a crosslinking agent. However, this technique has insufficient printing durability of several thousand sheets.

  Further, a thermosensitive lithographic printing plate precursor having a hydrophilic layer containing a colloid such as silica and a water-soluble overcoat layer on a support having an ink-receptive surface or coated with an ink-receptive layer is described. (See Patent Document 3). In the lithographic printing plate precursor having this overcoat layer, ablation is suppressed during laser irradiation, and the interface between the ink receiving layer and the hydrophilic layer is in a peeled state. And / or removed by ink to obtain a printing plate. That is, the overcoat layer and the hydrophilic layer in the exposed area are removed by on-press development. In this system, it is described that contamination of the exposure apparatus due to scattering of ablation residues is avoided.

Furthermore, it is known that the printing durability can be improved by incorporating an epoxy resin having a softening point of 120 ° C. or higher in the ink receiving layer (see Patent Document 4).
International Publication No. 94/18005 Pamphlet International Publication No. 98/40212 Pamphlet JP 2001-96936 A JP 2001-260553 A

  The lithographic printing plate precursor according to the prior art still has insufficient printing durability, and further improvements have been desired. The present invention meets this need. That is, an object of the present invention is to provide a heat-sensitive lithographic printing plate precursor having improved printing durability and requiring no development treatment.

The present inventor was able to solve the above problems by improving the adhesion between the ink receiving layer and the hydrophilic layer. That is, the present invention is as follows.
1. On the support, (1) an ink receiving layer, and (2) at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals A hydrophilic layer containing colloidal particulate oxides or hydroxides in this order, and at least one of the ink receiving layer and the hydrophilic layer is a heat-sensitive lithographic printing plate precursor containing a photothermal conversion agent. The ink-receiving layer side by side with at least one functional group selected from a cationic group, a group containing two carbonyl groups with one carbon atom or nitrogen atom in between, and a lactone group 1. A heat-sensitive lithographic printing plate precursor comprising a polymer having a chain.

2. On the support, at least one element selected from (1) an ink receiving layer, (2) beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and a transition metal A hydrophilic layer containing a colloidal particulate oxide or hydroxide, and (3) a hydrophilic overcoat layer that can be removed on a printing press in this order, and includes an ink receiving layer, a hydrophilic layer and an overcoat layer. A heat-sensitive lithographic printing plate precursor comprising at least one layer containing a photothermal conversion agent, wherein the ink-receiving layer comprises two carbonyls each having a cationic group, and one carbon atom or nitrogen atom interposed therebetween. A heat-sensitive lithographic plate comprising a polymer having a group containing a group and a side chain having at least one functional group selected from a lactone group Printing plate precursor.

  The present invention has solved the above problems by improving the adhesion between the ink receiving layer and the hydrophilic layer. This adhesion improvement is achieved by the functional groups (cationic groups, groups containing two carbonyl groups with one carbon atom or nitrogen atom in between, and / or lactone groups, which the polymer contained in the ink receiving layer has. ) Is obtained by interacting with the colloidal particulate oxide or hydroxide of the hydrophilic layer.

  Conventionally, when the adhesion between the ink receiving layer and the hydrophilic layer is improved, the energy to peel off the interface between the two layers by exposure increases, so that the sensitivity generally decreases. Although the mechanism of action is not clear, the printing durability could be improved without lowering the sensitivity.

  According to the present invention, it is possible to provide a heat-sensitive lithographic printing plate precursor capable of recording an image by scanning exposure and requiring no development process and improved printing durability.

  Hereinafter, elements such as an ink receiving layer, a hydrophilic layer, and a support constituting the original plate for a heat-sensitive lithographic printing plate of the present invention will be described in detail.

(Ink receiving layer)
The ink-receiving layer used in the present invention has at least one functional group selected from a cationic group, a group containing two carbonyl groups with one carbon atom or nitrogen atom in between, and a lactone group. It contains a polymer having a side chain.

  In the following, a cationic group, a group containing two carbonyl groups with one carbon atom or nitrogen atom in between, and a lactone group as a specific functional group, at least one functional group selected from these May be referred to as a specific polymer.

  Examples of the cationic group include onium groups (for example, ammonium group, phosphonium group, arsonium group, stibonium group, oxonium group, sulfonium group, selenonium group, stannonium group, iodonium group). Among these, an ammonium group, a phosphonium group, a sulfonium group, and an iodonium group are preferable, an ammonium group and a phosphonium group are more preferable, and an ammonium group is most preferable.

  The ammonium group is the following formula (I), the phosphonium group is the following formula (II), the arsonium group is the following formula (III), the stibonium group is the following formula (IV), the oxonium group is the following formula (V), and the sulfonium group is the following formula (VI), the selenonium group is defined by the following formula (VII), the stannonium group is defined by the following formula (VIII), and the iodonium group is defined by the following formula (IX).

Ammonium group: (I) -N ⁺ R ₃
Phosphonium group: (II) -P ⁺ R ₃
Arsonium group: (III) -As ⁺ R ₃
Stivonium group: (IV) -Sb ⁺ R ₃
Oxonium group: (V) -O ⁺ R ₂
Sulfonium group: (VI) -S ⁺ R ₂
Selenonium group: (VII) -Se ⁺ R ₂
Stannonium group: (VIII) -Sn ⁺ R ₂
Iodonium group: (IX) -I ⁺ R

  In each formula, R is a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group. A plurality of R contained in one onium group may be different.

  In the above formulas (I) to (IX), the aliphatic group may have a cyclic structure or a branched structure. The aliphatic group has preferably 1 to 20 carbon atoms, more preferably 1 to 15, more preferably 1 to 10, still more preferably 1 to 8, and even more preferably 1 to 15. It is most preferable that it is thru | or 6.

Moreover, the aliphatic group may have a substituent. Examples of substituents include halogen atoms (F, Cl, Br, I), amino groups, hydroxyl groups, mercapto groups, carboxyl groups, sulfo groups, sulfate ester groups, phosphono groups, phosphate ester groups, cyano groups, aromatics Group, heterocyclic group, —O—R, —S—R, —CO—R, —NH—R, —N (—R) ₂ , —N ⁺ (—R) ₃ , —CO—O—R , -O-CO-R, -CO-NH-R, -NH-CO-R, and -P (= O) (-O-R) ₂ . Each R is an aliphatic group, an aromatic group or a heterocyclic group. The carboxyl group, sulfo group, sulfate ester group, phosphono group and phosphate ester group may be in the form of a salt even if the hydrogen atom is dissociated.

  In the above formulas (I) to (IX), the aromatic group has preferably 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms.

Examples of aromatic substituents include halogen atoms (F, Cl, Br, I), amino groups, hydroxyl groups, mercapto groups, carboxyl groups, sulfo groups, sulfate ester groups, phosphono groups, phosphate ester groups, Cyano group, aliphatic group, aromatic group, heterocyclic group, —O—R, —S—R, —CO—R, —NH—R, —N (—R) ₂ , —N ⁺ (—R) ₃ , —CO—O—R, —O—CO—R, —CO—NH—R, —NH—CO—R, and —P (═O) (— O—R) ₂ . Each R is an aliphatic group, an aromatic group or a heterocyclic group. The carboxyl group, sulfo group, sulfate ester group, phosphono group and phosphate ester group may be in the form of a salt even if the hydrogen atom is dissociated.

  In the above formulas (I) to (IX), the heterocyclic group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, still more preferably 1 to 10 carbon atoms. It is still more preferable that it is 8 to 8, and it is most preferable that it is 1 to 6.

  The heterocyclic group may have a substituent. Examples of the substituent include the same as the examples of the substituent of the aromatic group.

  A group represented by the following formula (X) or formula (XI) is preferable as the functional group containing two carbonyl groups in which one carbon atom or nitrogen atom is interposed in the middle according to the present invention.

In the formula (X), R ¹ is an aliphatic group, an aromatic group, a heterocyclic group, or —O—R ⁴ , and R ⁴ is a hydrogen atom or an aliphatic group. R ¹ is preferably an aliphatic group. R ² and R ³ are each independently a hydrogen atom or an aliphatic group. R ² and R ³ are preferably hydrogen atoms.

  In the formula (X), the aliphatic group may have a cyclic structure or a branched structure. The number of carbon atoms in the aliphatic group is preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 15, and still more preferably 1 to 10. It is most preferable that it is thru | or 6.

The aliphatic group may have a substituent. Examples of substituents include halogen atoms (F, Cl, Br, I), hydroxyl groups, mercapto groups, formyl groups, amino groups, ammonio groups, carboxyl groups, carbamoyl groups, carbamoyloxy groups, sulfo groups, ureido groups, Sulfinamoyl group, sulfamoyl group, silyl group, hydroxysilyl group, phosphono group, cyano group, nitro group, aromatic group, heterocyclic group, -O-R, -S-R, -S-S-R, -CO- R, -NH-R, -N ( -R) 2, -N + H 2 -R, -N + H (-R) 2, -N + (-R) 3, -CO 2 -R, -S -CO-R, -CO-NH- R, -CO-N (-R) 2, -CO 2 -NH-R, -CO 2 -N (-R) 2, -NH-CO-R, -N (-R) -CO-R, -SO -R, -SO 2 -R, -SO 3 -R, -NH-CO-NH-R, NH-CO-N (-R) 2, -N (-R) -CO-NH-R, -N (-R) -CO-N (-R) 2, -NH-CO 2 -R, -N (—R) —CO ₂ —R, —SO—NH—R, —SO—N (—R) ₂ , —SO ₂ —NH—R, —SO ₂ —N (—R) ₂ , —SO ₂ — NH—SO ₂ —R, —CO—NH—SO ₂ —R, —Si (—O—R) ₃ , —P (═O) (— OH) (— O—R) and —P (═O) (—O—R) ₂ may be mentioned. The -CO ₂ - means a -CO-O- or -O-CO-. The —SO ₃ — means —SO ₂ —O— or —O—SO ₂ —. Each R is an aliphatic group, an aromatic group or a heterocyclic group. A plurality of R contained in the same group may be different from each other. The carboxyl group, sulfo group, sulfate ester group, phosphono group and phosphate ester group may be in the form of a salt even if the hydrogen atom is dissociated.

  In formula (X), the aromatic group has preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and most preferably 6 to 15 carbon atoms.

  The aromatic group may have a substituent.

Examples of substituents include halogen atoms (F, Cl, Br, I), hydroxyl groups, mercapto groups, formyl groups, amino groups, ammonio groups, carboxyl groups, carbamoyl groups, carbamoyloxy groups, sulfo groups, ureido groups, Sulfinamoyl group, sulfamoyl group, silyl group, hydroxysilyl group, phosphono group, cyano group, nitro group, aliphatic group, aromatic group, heterocyclic group, -O-R, -S-R, -S-S-R , -CO-R, -NH-R , -N (-R) 2, -N + H 2 -R, -N + H (-R) 2, -N + (-R) 3, -CO 2 - R, —S—CO—R, —CO—NH—R, —CO—N (—R) ₂ , —CO ₂ —NH—R, —CO ₂ —N (—R) ₂ , —NH—CO— R, -N (-R) -CO- R, -SO-R, -SO 2 -R, -SO 3 -R, -NH-CO- H-R, -NH-CO- N (-R) 2, -N (-R) -CO-NH-R, -N (-R) -CO-N (-R) 2, -NH-CO 2 _{-R, -N (-R) -CO 2} -R, -SO-NH-R, -SO-N (-R) 2, -SO 2 -NH-R, -SO 2 -N (-R) 2 , —SO ₂ —NH—SO ₂ —R, —CO—NH—SO ₂ —R, —Si (—O—R) ₃ , —P (═O) (— OH) (— O—R) and — P (═O) (— O—R) ₂ is mentioned. The -CO ₂ - means a -CO-O- or -O-CO-. The —SO ₃ — means —SO ₂ —O— or —O—SO ₂ —. Each R is an aliphatic group, an aromatic group or a heterocyclic group. A plurality of R contained in the same group may be different from each other. The carboxyl group, sulfo group, sulfate ester group, phosphono group and phosphate ester group may be in the form of a salt even if the hydrogen atom is dissociated.

  In the formula (X), the number of carbon atoms of the heterocyclic group is preferably 1 to 30, more preferably 1 to 20, further preferably 1 to 15, and more preferably 1 to 10. More preferably, it is preferably 1 to 6.

  The heterocyclic group may have a substituent. The example of a substituent is the same as the example of the substituent of an aromatic group.

The nitrogen atom having an unshared electron pair contained in R ¹ , R ² and R ³ is preferably contained in an amino group, a substituted amino group or an aromatic heterocyclic ring. The substituent of the substituted amino group is preferably an aliphatic group or an aromatic group, more preferably an aliphatic group, and most preferably an alkyl group or a substituted alkyl group.

  More preferably, the nitrogen atom having an unshared electron pair is contained in an aromatic heterocyclic ring. The aromatic heterocyclic ring is preferably a 5-membered ring or a 6-membered ring. Examples of the aromatic heterocycle (monocycle) containing a nitrogen atom having an unshared electron pair include a pyrrole ring, a pyridine ring, a pyrazole ring, an imidazole ring, a triazole ring, a tetrazole ring, an isoxazole ring, an oxazole ring, Examples include thiazole ring, thiazole ring, thiadiazole ring, pyridazine ring, pyrimidine ring, pyrazine ring and triazine ring.

  An aromatic heterocyclic ring, another heterocyclic ring or an aliphatic ring may be condensed to the aromatic heterocyclic ring. Examples of fused rings include indole ring, carbazole ring, azaindole ring, indazole ring, benzimidazole ring, benzotriazole ring, benzisoxazole ring, benzoxazole ring, benzothiazole ring, purine ring, quinoline ring, isoquinoline ring, Examples include acridine ring, phthalazine ring, quinazoline ring, quinoxaline ring, naphthyridine ring, phenanthroline ring and pteridine ring.

  The aromatic heterocyclic ring and its condensed ring may have a substituent. The example of a substituent is the same as the example of the substituent of the aromatic group mentioned above.

  The functional group containing a nitrogen atom having an unshared electron pair is a monovalent group corresponding to an atomic group obtained by removing one hydrogen atom bonded to a carbon atom of the aromatic heterocyclic ring and the condensed ring. Is preferred.

In the formula (XI), R ¹ and R ² have the same meanings as R ¹ and R ² of formula (X).

  The lactone group according to the present invention is not particularly limited as long as it has a lactone ring structure. Among them, a lactone group having a 5-membered lactone structure is particularly preferable.

  As a method for introducing the specific functional group (cationic group, group containing two carbonyl groups with one carbon atom or nitrogen atom in between, or lactone group) into the polymer side chain, for example, Examples thereof include a method of polymerizing or copolymerizing a monomer having a specific functional group by a known polymerization method. Moreover, the monomer which has a specific functional group can also be copolymerized with the monomer which does not have a specific functional group.

  As a monomer which has a specific functional group, the monomer which has a specific functional group and ethylene addition polymerizable unsaturated groups, such as a vinyl group, an allyl group, or a (meth) acryl group, is mentioned in a molecule | numerator. In addition, one monomer may have two or more specific functional groups (in this specification, “(meth) acryl” is used when referring to either or both of “acrylic and methacrylic”). Sometimes).

  Further, the specific functional group and the ethylenically unsaturated group are bonded via a single bond or a linking group, and the molecular weight of such a linking group is preferably 1000 or less.

  Specific examples of the monomer having a cationic group according to the present invention include the following compounds. However, it is not limited to these examples.

  Specific examples of the monomer having a group containing two carbonyl groups in which one carbon atom or nitrogen atom is interposed in the middle according to the present invention include the following compounds. However, it is not limited to these examples.

  Specific examples of the monomer having a lactone group according to the present invention include pantoyl lactone (meth) acrylate, α- (meth) acryloyl-γ-butyrolactone, β- (meth) acryloyl-γ-butyrolactone, and the following compounds: However, the present invention is not limited to these examples.

Examples of the copolymer component monomer that constitutes the specific polymer together with the monomer having the specific functional group include monomers shown in the following (A) to (K).
(A) Acrylic acid esters. Examples of this monomer group include methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid-n-butyl, acrylic acid-t-butyl, acrylic acid-t-amyl, hexyl acrylate, cyclohexyl acrylate, acrylic Acid-t-octyl, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate, o-, m (Substituted) acrylic esters such as-and p-hydroxyphenyl acrylate.

  (B) Methacrylic acid esters. Examples of this monomer group include methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylic acid-n-butyl, methacrylic acid-t-butyl, methacrylic acid-t-amyl, hexyl methacrylate, cyclohexyl methacrylate, methacrylic acid. Acid-t-octyl, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate, o-, (Substituted) methacrylic acid esters such as m- and p-hydroxyphenyl methacrylate.

  (C) Acrylamide and methacrylamide. Examples of this monomer group include acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethyl acrylamide, N-ethyl methacrylamide, Nt-butyl methacrylamide, N-hexyl acrylamide, N- Hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide, N-hydroxyethyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-phenyl methacrylamide, N-benzyl acrylamide, N-benzyl methacrylamide, N -Nitrophenylacrylamide, N-nitrophenylmethacrylamide, N-ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylate Ruamido, N-(4-hydroxyphenyl) acrylamide, acrylamide or methacrylamide, such as N-(4-hydroxyphenyl) methacrylamide.

(D) Vinyl ethers. Examples of this monomer group include ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, t-octyl vinyl ether, phenyl vinyl ether and the like.
(E) Vinyl esters. Examples of this monomer group include vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate and the like.
(F) Styrenes. Examples of this monomer group include styrene, methylstyrene, chloromethylstyrene, o-, m- and p-hydroxystyrene, o-, m- and p-carboxystyrene.

(G) Vinyl ketones. Examples of this monomer group include methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(H) Olefins. Examples of this monomer group include ethylene, propylene, isobutylene, butadiene, isoprene and the like.
(I) N-containing monomers. Examples of this monomer group include N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like.

  (J) Unsaturated sulfonamides. Examples of this monomer group include N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- [1- (3-amino Sulfonyl) naphthyl] acrylamide, acrylamides such as N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p- Methacrylamides such as aminosulfonylphenyl) methacrylamide, N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacrylamide, o-aminosulfonylphenyl acrylate, m -A Unsaturated sulfonamides such as acrylic acid esters such as nosulfonylsulfonyl acrylate, p-aminosulfonylphenyl acrylate, 1- (3-aminosulfonylphenylnaphthyl) acrylate, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, Examples include p-aminosulfonylphenyl methacrylate and 1- (3-aminosulfonylphenylnaphthyl) methacrylate.

  (K) Unsaturated acid anhydride. Examples of this monomer group include itaconic anhydride, maleic anhydride, 2,3-dimethylmaleic anhydride, 2-chloromaleic anhydride and the like.

  The content of the structural unit having a specific functional group in the specific polymer is preferably 1 mol% or more, more preferably 5 mol% or more, and most preferably 10 mol% or more.

  Moreover, as a weight average molecular weight of a specific polymer, it is preferable that it is 500-1,000,000, and it is more preferable that it is 1,000-500,000.

  Although the specific example of the specific polymer contained in the ink receiving layer of this invention is shown below, it is not limited to these examples.

  The ink receiving layer of the present invention can be provided by dissolving the above polymer in a suitable solvent and coating and drying on a support. Although it is possible to use only the above polymer by dissolving it in a solvent, a crosslinking agent, an adhesion assistant, a colorant, a coated surface condition improver, and a plasticizer can be added as necessary. In addition, a heating coloring or decoloring additive for forming a printout image after exposure may be added.

  Examples of the crosslinking agent include diazo resins, aromatic azide compounds, epoxy resins, isocyanate compounds, blocked isocyanate compounds, initial hydrolysis condensates of tetraalkoxy silicon, glyoxal, aldehyde compounds, and methylol compounds.

  As the adhesion aid, the diazo resin is excellent in adhesion to the support and the hydrophilic layer. In addition, a silane coupling agent, an isocyanate compound, and a titanium coupling agent are also useful.

  As the colorant, ordinary dyes and pigments are used, and in particular, rhodamine 6G chloride, rhodamine B chloride, crystal violet, malachite green oxalate, quinizarin, 2- (α-naphthyl) -5-phenyloxazole and the like. Is mentioned. Specific examples of other dyes include oil yellow # 101, oil yellow # 103, oil pink # 312, oil green BG, oil blue BOS, oil blue # 603, oil black BY, oil black BS, and oil black T-505. (Oriental Chemical Industries, Ltd.), Victoria Pure Blue, Crystal Violet (CI 42555), Methyl Violet (CI 42535), Ethyl Violet, Methylene Blue (CI 522015), Patent Pure Blue (manufactured by Sumitomo Sankoku Chemical Co., Ltd.), Brilliant Blue, Methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4-p-diethylaminophenyliminaftquinone, cyano-p-diethylaminophenylacetanilide Triphenylmethane, diphenylmethane, oxazine, xanthene, iminonaphthoquinone, azomethine, or anthraquinone dyes represented by JP-A-62-293247 or JP-A-9-179290. Can be mentioned.

  When the coloring matter is added to the ink receiving layer, it is usually in a proportion of about 0.02 to 10% by mass, more preferably about 0.1 to 5% by mass, based on the total solid content of the receiving layer.

  Furthermore, fluorine-based surfactants and silicon-based surfactants, which are well-known compounds as coating surface condition improvers, can also be used. Specifically, a surfactant having a perfluoroalkyl group or a dimethylsiloxane group is useful by adjusting the coating surface.

  Furthermore, a plasticizer is added to the ink receiving layer of the present invention, if necessary, in order to impart flexibility and the like of the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl fukurate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers of acrylic acid or methacrylic acid And polymers are used.

  Furthermore, examples of the additive for coloring or decoloring printing that can be added to the ink receiving layer of the present invention include thermal acid generators such as diazo compounds and diphenyliodonium salts and leuco dyes (leucomalachite green, leucocrystal). Violet, crystal violet lactone, etc.) and PH discoloring dyes (for example, dyes such as ethyl violet and Victoria pure blue BOH) are used in combination. In addition, a combination of an acid coloring dye and an acidic binder as described in EP-A-897134 is also effective. In this case, the association state forming the dye is broken by heating, and a lactone body is formed to change from colored to colorless. The addition ratio of these additives is preferably 10% by mass or less, more preferably 5% by mass or less, based on the solid content of the ink receiving layer.

  Solvents for applying the ink receiving layer include alcohols (methanol, ethanol, propyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc.) , Ethers (tetrahydrofuran, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, tetrahydropyran, etc.), ketones (acetone, methyl ethyl ketone, acetylacetone, etc.), esters (methyl acetate, ethyl acetate, ethylene glycol monomethyl ether monoacetate, gamma-butyrolactone, lactic acid) Methyl, ethyl lactate, etc.), amides (formamide, N- Chill formamide, pyrrolidone, N- methylpyrrolidone), or the like can be used. These solvents are used alone or in combination. The concentration of the ink receiving layer component (total solid content including additives) in the coating solution is preferably 1 to 50% by mass.

The dry coating amount of the ink-receiving layer of the present invention is preferably from 0.2 to 1.0 g / m ^2, more preferably from 0.3 to 0.7 g / m ^2, particularly preferably 0.3 to 0. 5 g / m ² . Within this range, good ink acceptability and printing durability can be obtained.

[Hydrophilic layer]
The hydrophilic layer of the present invention comprises a colloidal particulate 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. Contains as a main component.

  The colloidal particulate oxides or hydroxides of these elements are dispersed in the colloidal dispersion by various known methods such as hydrolysis of halides or alkoxy compounds of the above elements, or condensation of hydroxides, that is, , Made as colloidal particles. When added to a hydrophilic layer coating solution for providing a hydrophilic layer, it can be added in the state of a colloidal dispersion.

  Of these oxides or hydroxides of these elements, particularly preferred are oxides or hydroxides of at least one element selected from aluminum, silicon, titanium and zirconium.

  In the case of silica, colloidal particles of oxides or hydroxides of these elements preferably have a spherical shape of 5 to 100 nm in the case of silica. A pearl necklace-like colloidal particle in which spherical particles of 10 to 50 nm are continuous in a length of 50 to 400 nm can also be used. Feather-shaped particles such as 100 nm × 10 nm, such as aluminum oxide or hydroxide colloidal particles, are also effective. Commercially available products such as Nissan Chemical Industries, Ltd. can be purchased for these colloidal dispersions.

  As a dispersion medium for these colloidal particles, in addition to water, organic solvents such as methanol, ethanol, ethylene glycol monomethyl ether, and methyl ethyl ketone are also useful.

  If necessary, a hydrophilic resin can be added to the hydrophilic layer of the present invention to enhance the film property of the hydrophilic layer. As the hydrophilic resin, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl, carboxymethyl and the like are preferable.

  Specific examples of hydrophilic resins include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and sodium salts thereof, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymer, styrene-maleic acid copolymer, polyacrylic acid and the like Salts, polymethacrylic acid and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers and copolymers of hydroxypropyl acrylate, hydroxybutyl methacrylate Homopolymers and copolymers, hydroxybutyl acrylate homopolymers and copolymers, polyethylene Recall, polypropylene oxide, polyvinyl alcohol, and hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, homopolymers and copolymers of acrylamide, methacrylamide homopolymers having a degree of hydrolysis of at least 60 mol%, preferably at least 80 mol% Examples thereof include polymers and polymers, homopolymers and copolymers of N-methylolacrylamide, and the like.

  The addition ratio of these hydrophilic resins is preferably 40% by mass or less, more preferably 20% by mass or less, based on the solid content of the hydrophilic layer.

  Moreover, the resin which has an aromatic hydroxyl group can also be used for the hydrophilic layer of this invention. In the case of using a resin having an aromatic hydroxyl group, it is possible to improve the imprinting property of printing as well as improving the film property of the hydrophilic layer. The resin having an aromatic hydroxyl group is preferably one that dissolves in methanol at 5% by mass or more at 25 ° C., and examples thereof include alkali-soluble resins such as novolak resin, resol resin, polyvinylphenol resin, and ketone pyrogallol resin.

  Preferred novolak resins include phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, and at least one hydroxyl group-containing aromatic compound selected from 3,5-xylenol and resorcin, formaldehyde, Examples thereof include novolak resins obtained by addition condensation with at least one selected from aldehydes such as acetaldehyde and propionaldehyde under an acidic catalyst. Paraformaldehyde and paraaldehyde may be used in place of formaldehyde and acetaldehyde, respectively.

  Among them, the mixing ratio of m-cresol: p-cresol: 2,5-xylenol: 3,5-xylenol: resorcin is 40 to 100: 0 to 50: 0 to 20: 0 to 20: 0 to 20 in molar ratio. Or a novolak resin which is an addition condensate of a mixture of phenol: m-cresol: p-cresol with a molar ratio of 1-100: 0 to 70: 0-60 and an aldehyde. Of the aldehydes, formaldehyde is particularly preferable. The novolak resin has a weight average molecular weight of preferably 1,000 to 15,000, more preferably 1,500 to 10,000.

  Preferred resole resins include phenol, m-cresol, o-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, resorcin, pyrogallol, bis- (4-hydroxyphenyl) methane, bisphenol-A, Hydroxyl-containing aromatic hydrocarbons such as o-ethylphenol, m-ethylphenol, p-ethylphenol, propylphenol, n-butylphenol, t-butylphenol, 1-naphthol and 2-naphthol, and other two or more hydroxyl groups At least one kind of polynuclear aromatic hydrocarbons having an aldehyde such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, furfural, etc., and acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. Those engaged at least one aldehyde or ketone and the additional condensation selected from ketones.

  Paraformaldehyde and paraaldehyde may be used in place of formaldehyde and acetaldehyde, respectively. The weight average molecular weight of the resole resin is preferably 500 to 10,000, particularly preferably 1,000 to 5,000.

  Preferred polyvinylphenol resins include o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (o-hydroxyphenyl) propylene, 2- (m-hydroxyphenyl) propylene, 2- (p-hydroxyphenyl). Examples thereof include single or two or more copolymers of hydroxystyrenes such as propylene. Hydroxystyrenes may have a substituent such as a halogen such as chlorine, bromine, iodine, fluorine or an alkyl group having 1 to 4 carbon atoms in the aromatic ring. And polyvinylphenol which may have a halogen or an alkyl group having 1 to 4 carbon atoms.

  In addition, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (o-hydroxyphenyl) propylene, 2- (m-hydroxyphenyl) propylene, 2- (p-hydroxyphenyl) propylene, etc. Copolymers of hydroxystyrenes with methacrylic acid, acrylic acid, methacrylic acid alkyl esters and acrylic acid alkyl esters are also useful.

  The polyvinylphenol resin is usually obtained by polymerizing hydroxystyrene, which may have a substituent, alone or in the presence of a radical polymerization initiator or a cationic polymerization initiator. Such polyvinyl phenol resin may be partially hydrogenated. Moreover, the resin which protected some hydroxyl groups of polyvinyl phenol resin by t-butoxycarbonyl group, a pyranyl group, a furanyl group, etc. may be sufficient. The weight average molecular weight of the polyvinylphenol resin is preferably 1,000 to 100,000, particularly preferably 1,500 to 50,000.

  As the ketone pyrogallol resin, acetone pyrogallol resin is particularly useful.

  The addition ratio of the resin having an aromatic hydroxyl group is preferably 20% by mass or less, more preferably 12% by mass or less, based on the solid content of the hydrophilic layer.

  A cross-linking agent that promotes cross-linking of the colloidal oxide or hydroxide may be added to the hydrophilic layer of the present invention. As such a crosslinking agent, an initial hydrolysis condensate of tetraalkoxysilane, trialkoxysilylpropyl-N, N, N-trialkylammonium halide, or aminopropyltrialkoxysilane is preferable. The addition ratio is preferably 5% by mass or less of the solid content of the hydrophilic layer.

  Furthermore, the hydrophilic layer of the present invention may be added with the above-mentioned hydrophilic resin or a resin crosslinking agent having an aromatic hydroxyl group for the purpose of increasing the printing durability at the time of printing. Examples of such a crosslinking agent include formaldehyde, glyoxal, polyisocyanate, initial hydrolysis / condensation product of tetraalkoxysilane, dimethylol urea and hexamethylol melamine.

  Furthermore, in order to improve the surface state of the coating, a well-known fluorine-based surfactant, silicon-based surfactant, polyoxyethylene-based surfactant, or the like may be added to the hydrophilic layer of the present invention. .

  The hydrophilic layer of the present invention is provided by preparing a solution prepared by dissolving or dispersing each of the above components in a solvent and applying the solution. As the main solvent of the hydrophilic layer coating solution, water and low-boiling alcohols such as methanol, ethanol, and propanol are used alone or as a mixture.

  In the present invention, a solvent capable of dissolving the lipophilic polymer of the ink receiving layer can be added to the main solvent for high printing durability. Examples of such a solvent include organic solvents described in JP-A No. 2001-180141. The good solvent of this organic polymer is difficult to specify because it varies depending on the individual organic polymer used in the ink-receiving layer, but generally alcohols (ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl) Ethers), ethers (tetrahydrofuran, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, tetrahydropyran, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, cyclohexanone, etc.), esters (methyl acetate, ethyl acetate, isobutyl acetate) , Ethylene glycol monomethyl monoacetate, etc.), amides (formamide, N-methylformamide, pyrrolidone, N-methylpyrrolidone, etc.), cancer Butyrolactone, a methyl lactate, a solvent selected from among such ethyl lactate.

  The content of the solvent that dissolves the lipophilic polymer in the ink receiving layer is preferably 0.4 to 40% by mass of the total solvent of the hydrophilic layer coating solution. More preferably, it is 0.4-20 mass%.

The dry coating amount of the hydrophilic layer of the present invention is preferably 0.2 to 0.8 g / m ² , more preferably 0.3 to 0.5 g / m ² . Within this range, good water retention of the hydrophilic layer can be obtained without causing deterioration in on-press developability and sensitivity.

[Support]
The support for the heat-sensitive lithographic printing plate precursor according to the invention is preferably an aluminum support having a roughened surface and an anodized film. As the raw material aluminum plate, a publicly known and used aluminum plate can be used as appropriate. That is, the raw material aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and a trace amount of foreign elements. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. Content of the different element in an alloy is 10 mass% or less. Further, it may be an aluminum plate from an aluminum ingot using a DC casting method or an aluminum plate from an ingot by a continuous casting method.

  The thickness of the aluminum support used in the present invention is 0.05 to 0.6 mm, preferably 0.1 to 0.4 mm, particularly preferably 0.15 to 0.3 mm.

  The roughening treatment on the surface of the aluminum plate can be performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, a method of chemically dissolving a surface selectively, or a combination of two or more of these methods can be performed. . As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. 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 No. 54-31187 is suitable. In addition, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Further, as disclosed in JP-A-54-63902, an electrolytic surface roughening method using a mixed acid can also be used.

  The roughened aluminum plate is subjected to an alkali etching treatment with an aqueous solution of potassium hydroxide, sodium hydroxide or the like as necessary, further neutralized, and then anodized.

  As an electrolyte used for anodizing treatment of an aluminum plate, various electrolytes that form a porous oxide film can be used. Generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, sulfamic acid, benzenesulfonic acid are used. Alternatively, a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.

The treatment conditions for anodization vary depending on the electrolyte used and cannot be specified. However, in general, the electrolyte concentration is 1 to 80% by mass solution, the liquid 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 50 minutes are suitable. Among these anodizing treatments, in particular, the method of anodizing at a high current density in sulfuric acid described in British Patent 1,412,768 and US Pat. No. 3,511,661. The method of anodizing phosphoric acid described in the above as an electrolytic bath is preferable.

The oxide film amount of the aluminum support of the present invention is 3.0 g / m ² or more and less than 5.0 g / m ² . More preferably, it is 3.2-4.5 g / m < ² >, Most preferably, it is 3.5-4.0 g / m < ² >. A good heat insulation effect can be obtained within this range.

  As the support used in the present invention, the support having the anodized film subjected to the surface treatment as described above may be used as it is. However, for further improvement in adhesion to the upper layer, heat insulation, etc., as necessary, In addition, micropore sealing treatment of an anodized film described in JP-A-2001-253181, surface hydrophilization immersed in an aqueous solution containing a hydrophilic compound described in JP-A-2001-322365 It is possible to select and perform processing.

  Suitable hydrophilic compounds for the hydrophilization treatment include polyvinylphosphonic acid, compounds having sulfonic acid groups, saccharide compounds, citric acid, alkali metal silicates, potassium zirconium fluoride, phosphate / inorganic fluorine compounds, etc. Is mentioned.

The surface roughness of the aluminum support obtained as described above is preferably 0.45 μm or more, more preferably 0.48 μm or more, and particularly preferably 0.52 μm or more in terms of centerline average roughness Ra. The upper limit of the Ra value is related to the coating thickness of the ink receiving layer to be coated thereon, and thus cannot be determined in general, but generally it is preferably up to about 0.7 μm. Within this range, the surface of the ink receiving layer can be a rough surface exhibiting good adhesion to the hydrophilic layer.
[Back coat layer]
The back coat layer described in Japanese Patent Application No. 2002-205781 can be provided on the back surface of the support of the present invention. The backcoat layer can prevent scratches on the hydrophilic layer and the overcoat layer when the heat-sensitive lithographic printing plate precursor is laminated and conveyed. Such a back coat layer can be provided by applying a solution containing an organic polymer as a main component such as a saturated polyester resin, an unsaturated polyester resin, or an acetal resin on the back surface of the support.
[Overcoat layer]
The heat-sensitive lithographic printing plate precursor according to the present invention is for preventing the generation of debris due to ablation, and for preventing the hydrophilic layer from being contaminated or scratched by a lipophilic substance during storage or handling, or to prevent fingerprint traces from being attached with bare hands. It is preferable to provide a hydrophilic overcoat layer on the hydrophilic layer.

  The hydrophilic overcoat layer is removable on a printing press and contains a water-soluble resin or a resin selected from water-swellable resins that are partially cross-linked with water-soluble resins.

  Such a water-soluble resin is selected from water-soluble natural polymers and synthetic polymers, and is used together with a crosslinking agent, and a coated and dried film has a film forming ability.

  Specific examples of suitable water-soluble resins include natural gums, gum arabic, water-soluble soybean polysaccharides, fiber derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.), modified products thereof, white dextrin, For synthetic polymers such as pullulan and enzymatically degraded etherified dextrin, polyvinyl alcohol (polyvinyl acetate having a hydrolysis rate of 65 mol% or more), polyacrylic acid, alkali metal salt or amine salt thereof, 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 , Polyvinylpyrrolidone, Copolymer, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, alkali metal salt or amine salt thereof, poly-2-acrylamide-2 -Methyl-1-propanesulfonic acid copolymer, its alkali metal salt or amine salt. Further, two or more kinds of these resins can be mixed and used depending on the purpose. However, the present invention is not limited to these examples.

  When at least one or more of the water-soluble resins are partially crosslinked to form an overcoat layer on the hydrophilic layer, the crosslinking is performed by a crosslinking reaction using a reactive functional group possessed by the water-soluble resin. The crosslinking reaction may be a covalent bond or an ionic bond.

  Crosslinking reduces the adhesiveness of the overcoat layer surface and improves handling, but if the crosslinking proceeds too much, the overcoat layer changes to oleophilic, making it difficult to remove the overcoat layer on the printing press. Appropriate partial cross-linking is preferred.

  The preferred degree of partial cross-linking is that when the printing plate precursor is immersed in water at 25 ° C., the hydrophilic overcoat layer does not elute for 30 seconds to 10 minutes, but elution is observed after 10 minutes or more. To the extent that

  Examples of the compound used for the crosslinking reaction include known polyfunctional compounds having crosslinking properties, such as polyepoxy compounds, polyisocyanate compounds, polyalkoxysilyl compounds, polyvalent metal salt compounds, polyamine compounds, aldehyde compounds, hydrazine, etc. In the crosslinking reaction, a known catalyst may be added to accelerate the reaction.

  Specific examples of known polyfunctional compounds having crosslinkability include the following compounds.

  Specific examples of the polyepoxy compound include glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, bisphenols or their And polycondensates of hydrogenated products and epihalohydrins.

  Specific examples of the polyamine include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, propylenediamine, polyethyleneimine, and polyamidoamine.

  Specific examples of the polyisocyanate compound include tolylene diisocyanate, diphenylmethane isocyanate, liquid diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, xylylene diisocyanate, naphthalene-1,5-diisocyanate, cyclohexanephenylene diisocyanate, isopropylbenzene-2,4-diisocyanate. And the like, aliphatic isocyanates such as hexamethylene diisocyanate and decamethylene diisocyanate, alicyclic diisocyanates such as cyclohexyl diisocyanate and isophorone diisocyanate, and polypropylene glycol / tolylene diisocyanate addition reaction products.

  As the silane compound, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-amino Propyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, dimethyldimethoxysilane , Dimethyldiethoxysilane, diphenyldiethoxysilane, 3-chloropropylmethyldimethoxysilane, vinyltris (methylethylketoxime) silane, methyltris (methylethylketoxime) silane, Sulfonyl triacetoxy silane, and the like.

  Titanate compounds include tetraethylorthosilicate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltoreactor noyl titanate, isopropyldimethacrylisostearoyl titanate, isopropylisostearoyldiacryl titanate, isopropyl (dioctylphosphate) titanate), isopropyltricumylphenyl Titanate, isopropyl tri (N-aminoethylaminoethyl) titanate, dicumylphenyloxyacetate titanate, diisostearoyl ethylene titanate, isopropyl triinstearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl phosphate) titanate, tetraisopropyl Screw Dioctyl phosphite) titanate, tetraoctyl bis (ditridisyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, Bis (dioctyl pyrophosphate) oxyacetate titanate, etc.

  Examples of aldehyde compounds include formaldehyde, acetaldehyde, propyl aldehyde, butyraldehyde, glyoxal, glutaraldehyde, terephthalaldehyde, and the like.

  Examples of the polyvalent metal salt compound include water-soluble salts of metals such as zinc, calcium, magnesium, barium, strontium, cobalt, manganese and nickel.

  These crosslinking agents can be used alone or in admixture of two or more. Among these cross-linking agents, a particularly preferable cross-linking agent is a water-soluble cross-linking agent, but a water-insoluble cross-linking agent can be used by being dispersed in water with a dispersant.

  Particularly preferred combinations of water-soluble resins and crosslinking agents include carboxylic acid-containing water-soluble resins / polyvalent metal compounds, carboxylic acid-containing water-soluble resins / water-soluble epoxy resins, and hydroxyl group-containing resins / dialdehydes.

  A suitable addition amount of the crosslinking agent is 0.5 to 10% by mass of the water-soluble resin. Within this range, good water resistance can be obtained without impairing the removability of the overcoat layer on the printing press.

  In addition, a nonionic surfactant can be mainly added to the overcoat layer in the case of aqueous solution coating for the purpose of ensuring the uniformity of coating. Specific examples of such nonionic surfactants include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecyl ether and the like. .

  The proportion of the nonionic surfactant in the total solids of the overcoat layer is preferably 0.05 to 5% by mass.

Dry coating amount of the overcoat layer of the present invention is preferably 0.1~4.0g / m ^2, more preferably ^{0.1~1.0g / m 2, 0.10~0.25g / m} 2 is Particularly preferred. Within this range, it is possible to prevent generation of ablation residue, good dirt and scratches, and prevention of fingerprint mark adhesion without impairing the removability of the overcoat layer on the printing press.

[Photothermal conversion agent]
In the present invention, when there is no overcoat layer, in at least one layer of the ink receiving layer and the hydrophilic layer, in the case of having the overcoat layer, in at least one layer of the ink receiving layer, the hydrophilic layer and the overcoat layer, In order to increase sensitivity, a photothermal conversion agent having a function of converting light into heat is contained. As a photothermal conversion agent, what is necessary is just a substance which absorbs infrared rays, especially near infrared rays (wavelength 700-2000 nm), and various well-known pigments, dyes or pigment | dyes, and metal microparticles | fine-particles can be used.

  For example, the pigments, dyes or pigments, and metal fine particles described in JP-A No. 2001-301350, Journal of the Japan Printing Society, pages 38 to 40 (2001) “New imaging materials, 2. Near-infrared absorbing pigments” Preferably used. As the pigment and the metal fine particles, those subjected to a known surface treatment can be used as necessary.

  More specifically, as dyes or pigments, U.S. Pat. Nos. 4,756,993 and 4,973,572, JP-A-9-96891, JP-A-10-268512, and 11- Cyanine dyes, polymethine dyes, azomethine dyes, squarylium dyes, pyrylium and thiopyrylium salt dyes, dithiol metal complexes described in Japanese Patent Nos. 235883, 5-13514, 5-19702, and JP-A-2001-347765 And phthalocyanine dyes. Particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and phthalocyanine dyes.

  Examples of the pigment include insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, Kinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these, carbon black is particularly preferable.

  As the metal fine particles, fine particles of Ag, Au, Cu, Sb, Ge and Pb are preferable, and fine particles of Ag, Au and Cu are more preferable.

  The addition ratio of the photothermal conversion agent is preferably 1 to 50% by mass of the solid content of the hydrophilic layer in the hydrophilic layer, preferably 2 to 50% by mass of the solid content of the overcoat layer in the overcoat layer, and the ink receiving layer in the ink receiving layer. 20 mass% or less of layer solid content is preferable. Within these ranges, good sensitivity can be obtained without impairing the film strength of each layer.

[Plate making and printing method]
The heat-sensitive lithographic printing plate precursor according to the present invention forms an image (latent image) by heat prior to printing. Specifically, direct image-like recording using a thermal recording head, scanning exposure using an infrared laser, high-illuminance flash exposure such as a xenon discharge lamp, infrared lamp exposure, and the like are used, but a semiconductor that emits infrared light having a wavelength of 700 to 1200 nm. Exposure by a solid high-power infrared laser such as a laser or a YAG laser is suitable.

  The printing plate precursor of the present invention having a latent image formed thereon can be mounted on a printing machine without further processing. When printing is started using ink and fountain solution, the overcoat layer is removed by the fountain solution, and at the same time, the hydrophilic layer in the exposed area is also removed. Be started.

  Further, the heat-sensitive lithographic printing plate precursor according to the present invention is also used in a system for printing after being mounted on a plate cylinder of a printing machine, exposed to a laser mounted on the printing machine, and subsequently developed on the machine. .

Examples 1-7 and Comparative Example 1
[1. Preparation of heat-sensitive lithographic printing plate precursor]
Rolling thickness of 0.30 mm of JISA1050 aluminum material containing 99.5% by weight of aluminum, 0.01% by weight of copper, 0.03% by weight of titanium, 0.3% by weight of iron and 0.1% by weight of silicon The surface of the plate was grained using a 20% by mass aqueous suspension of 400 mesh Pamiston (manufactured by Kyoritsu Ceramics) and a rotating nylon brush (6,10-nylon), and then washed thoroughly with water. This was immersed in a 15% by mass aqueous sodium hydroxide solution (containing 4.5% by mass aluminum ions) and etched so that the dissolved amount of aluminum was 8 g / m ² , and then washed with running water. Further, neutralized with a 1% by mass nitric acid aqueous solution, and then in a 0.7% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions), a rectangular wave with an anode voltage of 10.5V and a cathode voltage of 9.3V Electrolytic surface roughening treatment was carried out at an anode quantity of electricity of 240 C / dm ² using an alternating waveform voltage (current ratio r = 0.90, current waveform described in Example of Japanese Patent Publication No. 58-5796). . After washing with water, it was immersed in a 10% by mass aqueous sodium hydroxide solution at 35 ° C. and etched so that the amount of dissolved aluminum was 0.9 g / m ² , followed by washing with water. Next, it was immersed in a 30% by mass sulfuric acid aqueous solution at 50 ° C., desmutted, and washed with water. Further, a porous anodic oxide film forming treatment was performed using a direct current in a 9 mass% sulfuric acid aqueous solution (containing 0.6 mass% aluminum ions) at 53 ° C. That is, the electrolysis time was 33 seconds, and the amount of anodized film was 3.7 g / m ² by adjusting the current density. Subsequently, it was washed with water and dried to obtain an aluminum support. The center line average roughness Ra of the obtained support was 0.53 μm.

Next, the following back coat layer coating solution was applied to the back surface of the aluminum support with a bar coater and dried by heating (100 ° C., 1 minute), whereby the coating amount after drying was 0.4 g / m ² (thickness). A support having a 0.4 μm back coat layer formed thereon was obtained.

<Backcoat layer coating solution>
Saturated copolymer polyester resin (Chemit K-1294 (trade name), manufactured by Toray, glass transition point: 100 ° C.) 4.0 g
・ Fluorine surfactant (Megafac F-177 (trade name), manufactured by Dainippon Ink and Chemicals, Inc.)
0.05g
・ Methyl ethyl ketone 100g

A bar coater with the ink receiving layer coating liquids (L1-1) to (L1-8) shown in Table 1 on the surface of the aluminum support having the backcoat layer so that the liquid amount is 12 cm ³ / m ^2. It was applied with. Thereafter, the ink was dried by heating at 100 ° C. for 1 minute to obtain an ink receiving layer having a dry coating amount of 0.42 g / m ² .

The following hydrophilic layer coating solution was coated on the ink receiving layer with a bar coater so that the coating solution amount was 12 cm ³ / m ² . Then, it dried by heating at 100 ° C. for 1 minute to obtain a hydrophilic layer having a dry coating amount of 0.40 g / m ² .

<Hydrophilic layer coating solution>
・ Methanol 19.4g
・ Methyl lactate 0.1g
Methanol silica sol (manufactured by Nissan Chemical Industries, Ltd., colloid of methanol solution containing 30% by mass of 10-20 nm silica particles) 3.0 g
・ Polyacrylic acid (weight average molecular weight 250,000, manufactured by Wako Pure Chemical Industries, Ltd.) 0.1 g

On the hydrophilic layer, the overcoat layer coating solution is applied with a bar coater so that the liquid amount becomes 12 cm ³ / m ^2, and then dried by heating at 100 ° C. for 1.5 minutes, and the dry coating amount is 0.15 g / m ² . An overcoat layer was provided to prepare a thermosensitive lithographic printing plate precursor.

<Overcoat coating solution>
・ Gum arabic (28% by weight aqueous solution) 1.5g
・ Photothermal conversion agent (infrared absorber 2 below) 0.042g
・ Emalex # 710 (10% by weight aqueous solution, surfactant manufactured by Nippon Emulsion Co., Ltd.)
0.168g
Magnesium acetate tetrahydrate (10% by weight aqueous solution, manufactured by Wako Pure Chemical Industries, Ltd.)
0.03g
・ Water 30.06g

[2. Printing evaluation of original plate for heat-sensitive lithographic printing plate]
The heat-sensitive lithographic printing plate precursor thus obtained was attached to a trend setter 3244VX manufactured by Creo and exposed while changing the drum rotation speed to 150 rpm and the laser output from 9 W to 17 W to form a latent image. The original plate on which the latent image was formed was attached to a SOR-M printing machine manufactured by Heidelberg, and dampening water and barius ink (Dainippon Ink Chemical Industries, Ltd.) comprising an aqueous solution of 4% by volume IF102 (manufactured by Fuji Photo Film Co., Ltd.). And the laser output value capable of forming an image was estimated.

  Further, an original plate on which a latent image was formed with a laser output of 17 W was printed in the same manner, and printing durability was evaluated. The evaluation results are shown in Table 2.

  From Table 2, it can be seen that the polymer having the specific functional group of the present invention has a remarkable effect in improving the printing durability and is also excellent in sensitivity.

Example 8
In the heat-sensitive lithographic printing plate precursor using the same amount of alumina sol or titania sol in the solid content instead of the methanol silica sol of the hydrophilic layer coating solution of Example, substantially the same as the heat-sensitive lithographic printing plate precursor of Example 1, Improvement in printing durability and good sensitivity can be obtained.

Claims (2)

On the support, (1) an ink receiving layer, and (2) at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals A hydrophilic layer containing colloidal particulate oxides or hydroxides in this order, and at least one of the ink receiving layer and the hydrophilic layer is a heat-sensitive lithographic printing plate precursor containing a photothermal conversion agent. The ink-receiving layer side by side with at least one functional group selected from a cationic group, a group containing two carbonyl groups with one carbon atom or nitrogen atom in between, and a lactone group 1. A heat-sensitive lithographic printing plate precursor comprising a polymer having a chain. On the support, at least one element selected from (1) an ink receiving layer, (2) beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and a transition metal A hydrophilic layer containing a colloidal particulate oxide or hydroxide, and (3) a hydrophilic overcoat layer that can be removed on a printing press in this order, and includes an ink receiving layer, a hydrophilic layer and an overcoat layer. A heat-sensitive lithographic printing plate precursor comprising at least one layer containing a photothermal conversion agent, wherein the ink-receiving layer comprises two carbonyls having a cationic group, and one carbon atom or nitrogen atom interposed therebetween A heat-sensitive lithographic plate comprising a polymer having a group containing a group and a side chain having at least one functional group selected from a lactone group Printing plate precursor.