JP2005274607A - Lithographic printing plate precursor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive lithographic printing plate precursor that is superior in printing durability and in chemical resistance. <P>SOLUTION: The lithographic printing plate precursor is obtained by sequentially disposing on a support an intermediate layer containing a polymer having a structure represented by Formula (I) in a side chain and an infrared laser sensitive positive recording layer, having a laminated structure of at least two or more layers, wherein the layer adjacent to the intermediate layer in the recording layer contains a polymer having a phenolic hydroxyl group. In the Formula (I), Y represents a group linking to a backbone skeleton of the polymer; R<SP>1</SP>represents H or a hydrocarbon group; and R<SP>2</SP>represents a divalent hydrocarbon group. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lithographic printing plate precursor, and more particularly to a positive lithographic printing plate precursor for so-called direct plate making that can be directly made from a digital signal of a computer or the like.

  In recent years, the development of lasers has been remarkable. In particular, solid-state lasers and semiconductor lasers having a light emitting region from near infrared to infrared are easily available in high output and small size. These lasers are also very useful as an exposure light source for making a plate directly from digital data such as a computer in the field of lithographic printing.

  The positive type lithographic printing plate precursor for infrared laser includes an alkali-soluble resin (binder resin), an infrared absorber that absorbs light and generates heat (hereinafter sometimes referred to as “photothermal conversion substance”), and the binder resin And a compound (development inhibitor) that interacts with the developer to lower the solubility in the developer, but when an infrared absorber having a development inhibiting ability is used, the essential components are a binder resin and an infrared ray. Only absorbent. That is, this infrared absorber acts as a development inhibitor that substantially lowers the solubility of the binder resin in the developing solution by interaction with the binder resin in the unexposed area (image area), and the exposed area (non-image area). ), The interaction between the IR dye and the binder resin is weakened by the generated heat and is dissolved in an alkali developer to form an image.

As a support used for such a positive type lithographic printing plate precursor, extensive research has been conducted to make the support surface hydrophilic in order to prevent non-image areas from being stained. For example, when using a metal support such as an aluminum plate as a base material, there are various techniques such as anodized aluminum substrate, or silicate treatment of the anodized aluminum substrate to further increase the hydrophilicity. Proposed.
However, various treatments for improving hydrophilicity are not necessarily excellent in affinity with the recording layer, and in some cases, the adhesion between the support and the recording layer formed thereon is lowered. However, the recording layer peels off under severe printing conditions, and there is a problem that sufficient printing durability cannot be obtained.

  Therefore, in order to improve printing durability, a method of providing various intermediate layers between the support and the recording layer has been proposed. By using, as an intermediate layer, a resin material constituting the recording layer or a material having a functional group having excellent affinity with the support surface, the adhesion between the support surface and the recording layer in the image area is improved. Yes, for example, a lithographic printing plate provided with an intermediate layer containing a polymer compound containing a specific structural unit such as p-vinylbenzoic acid (see Patent Document 1), a monomer having an acid group and a monomer having an onium group A lithographic printing plate precursor (see Patent Document 2) provided with an intermediate layer containing a polymer (random polymer) containing However, these have a certain improvement effect on the above problem, but it is desired to further improve the printing durability by improving the adhesion between the support and the recording layer.

In addition, the adhesion between the support and the recording layer tends to be chemically weak, and the recording layer is easily peeled off by a developer, an ink cleaning solvent used during printing, a plate cleaner, etc. There was also a problem of poor chemical resistance.
Therefore, in order to improve chemical resistance, a lithographic printing plate precursor provided with an intermediate layer containing an amino acid group-containing polymer is known, but such a lithographic printing plate precursor has image forming properties, in particular, a non-image part. There was room for further improvement in the development removability (see, for example, Patent Document 3). It is known that the problem of image formability can be improved by making the recording layer a laminated structure having an alkali-soluble lower layer and an upper layer whose solubility in an alkali developer is improved by infrared laser exposure. However, in forming a recording layer having a laminated structure, it is necessary to use a polymer having low solubility in a general-purpose solvent in the lower layer from the viewpoint of recording layer coating properties. In that case, the intermediate layer and the recording layer As a result, there is a concern that printing durability and chemical resistance may be lowered.
JP-A-10-69092 JP 2000-108538 A Japanese Patent Application No. 2003-374189

  An object of the present invention, which has been made in consideration of the above-mentioned drawbacks of the prior art, is to provide a positive type lithographic printing plate precursor excellent in printing durability and chemical resistance.

As a result of intensive studies, the present inventor has found that the above object can be achieved by providing a recording layer having a laminated structure containing a specific component in the lowermost layer on an intermediate layer containing the specific component. It came to complete.
That is, the lithographic printing plate precursor according to the invention contains, on the support, a polymer having a structure represented by the following general formula (I) in the side chain (hereinafter referred to as “specific amino acid group-containing polymer” as appropriate). A lithographic printing plate precursor comprising an intermediate layer and an infrared laser-sensitive positive recording layer having a laminate structure of at least two layers, wherein the layer adjacent to the intermediate layer has a phenolic hydroxyl group. And a polymer (hereinafter referred to as “specific phenol polymer” as appropriate).

In general formula (I), Y represents a linking group to the polymer main chain skeleton. R ¹ represents a hydrogen atom or a hydrocarbon group. R ² represents a divalent hydrocarbon group.

  The polymer contained in a layer adjacent to the intermediate layer of the recording layer (hereinafter referred to as “lower layer” where appropriate) preferably has a sulfonamide group in addition to the phenolic hydroxyl group.

  Here, the layer structure of the recording layer is not particularly limited as long as it is composed of two or more layers each having different constituent components, and contains a polymer having a phenolic hydroxyl group in the lower layer. It is preferable to have a two-layer structure of an alkali-soluble lower layer containing a polymer having a phenolic hydroxyl group and an upper layer whose solubility in an alkali developer is improved by infrared laser exposure.

Although the operation of the present invention is not clear, it is presumed as follows.
Since the specific amino acid group-containing polymer used in the intermediate layer according to the present invention has the structure represented by the general formula (I) in the side chain, it strongly interacts with the surface of the support, and the support and the intermediate layer. A polymer having a phenolic hydroxyl group having a good interaction property with the structure represented by the general formula (I) at the lowermost layer of the recording layer adjacent to the intermediate layer. Therefore, it is considered that the adhesion between the intermediate layer and the recording layer is excellent. As a result, it is considered that the support, the intermediate layer, and the recording layer are firmly adhered to each other, and improvement in printing durability and chemical resistance is realized.

  According to the present invention, a positive lithographic printing plate precursor excellent in printing durability and chemical resistance can be provided.

The lithographic printing plate precursor of the present invention comprises, on a support, an intermediate layer containing a polymer having a structure represented by the general formula (I) in the side chain (a specific amino acid group-containing polymer), and at least two or more layers. A lithographic printing plate precursor provided with an infrared laser-sensitive positive recording layer having a laminated structure, and a polymer (specific phenol polymer) in which a layer (lower layer) adjacent to the intermediate layer of the recording layer has a phenolic hydroxyl group ).
First, the intermediate layer and the recording layer of such a lithographic printing plate precursor will be described in detail sequentially.

[Middle layer]
[Specific amino acid group-containing polymer]
The specific amino acid group-containing polymer used in the present invention is a polymer having a structure represented by the following general formula (I) in the side chain.

  In general formula (I), Y represents a linking group to the polymer main chain skeleton. Examples of the linking group represented by Y include a substituted or unsubstituted divalent hydrocarbon group. The hydrocarbon group may have one or more partial structures containing one or more heteroatoms selected from the group consisting of an oxygen atom, a nitrogen atom and a sulfur atom.

In general formula (I), R ¹ represents a hydrogen atom or a hydrocarbon group.
The hydrocarbon group represented by R ¹ is preferably a hydrocarbon group having 1 to 30 carbon atoms. Among these hydrocarbon groups, an alkyl group or an aryl group is more preferable.
The hydrocarbon group represented by R ¹ may further have a substituent described later, and the substituent is particularly preferably a group composed of a carboxyl group and a salt thereof.
As the hydrocarbon group represented by R ¹ , the most preferred embodiment is an alkyl group and an aryl group having a carboxyl group or a group consisting of a salt thereof.

The hydrocarbon group in R ¹ and the substituent that can be introduced into the hydrocarbon group will be described in detail.
Specific examples of the alkyl group represented by R ¹ include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, Tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 1-methylbutyl, isohexyl, 2-ethylhexyl, 2-methyl A hexyl group, a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-norbornyl group and the like have 1 to 30 carbon atoms, and examples thereof include a linear, branched, or cyclic alkyl group.

The aryl group represented by R ¹ includes those in which 2 to 4 benzene rings form a condensed ring and those in which a benzene ring and an unsaturated 5-membered ring form a condensed ring.
Specific examples of the aryl group represented by R ¹ include aryl groups having 6 to 30 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group, indenyl group, acebutenyl group, fluorenyl group, and pyrenyl group. Groups.

The hydrocarbon group represented by R ¹ may be substituted at one or more locations with any substituent. Examples of the substituent that can be introduced into R ¹ include a monovalent nonmetallic atomic group excluding a hydrogen atom. Specific examples include halogen atoms (-F, -Br, -Cl, -I), hydroxyl groups, alkoxy groups, aryloxy groups, mercapto groups, alkylthio groups, arylthio groups, alkyldithio groups, aryldithio groups, amino groups, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy Group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group , Acylamino group, N-alkylacylamino N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl- N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido 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 An alkylureido group, an N ′, N′-diaryl-N-arylureido group,

N'-alkyl-N'-aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxy Carbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and salts thereof A group consisting of: alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N- Arylcarbamoyl group, alkyl A sulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its a salt group, alkoxy sulfonyl group, aryloxy sulfonyl group, sulfinamoyl group, N- alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and the like Group consisting of salt, N-alkylsulfonylsulfamoyl group -SO ₂ NHSO ₂ (alkyl)) and its a salt group, N- aryl sulfonylsulfamoyl group _{(-SO 2 NHSO 2 (aryl)} ) and its a salt group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ (alkyl)) and a salt thereof,

N-arylsulfonylcarbamoyl group (—CONHSO ₂ (aryl)) and a salt thereof, alkoxysilyl group (—Si (Oalkyl) ₃ ), aryloxysilyl group (—Si (Oaryl) ₃ ), hydroxysilyl group ( -Si (OH) ₃ ) and groups thereof, phosphono groups (-PO ₃ H ₂ ) and groups thereof, dialkylphosphono groups (-PO ₃ (alkyl) ₂ ), diarylphosphono groups (- PO ₃ (aryl) ₂ ), an alkylarylphosphono group (—PO ₃ (alkyl) (aryl)), a monoalkylphosphono group (—PO ₃ H (alkyl)) and a salt thereof, a monoarylphosphono group (-PO ₃ H (aryl)) and its a salt group, phosphonooxy group (-OPO ₃ H ₂₎ and its a salt group, a dialkyl Suhonookishi group _{(-OPO 3 (alkyl) 2)} , diaryl phosphono group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphono group _{(-OPO 3 (alkyl) (aryl} )), monoalkyl phosphonooxymethyl Group (—OPO ₂ H (alkyl)) and a salt thereof, monoarylphosphonooxy group (—OPO ₃ H (aryl)) and a group thereof, cyano group, nitro group, aryl group, alkyl group Alkenyl group and alkynyl group.

Among these, as the substituent that can be introduced into R ¹ , a group composed of a carboxyl group and a salt thereof, an alkoxycarbonyl group, and an aryloxycarbonyl group are more preferable, and a group composed of a carboxyl group and a salt thereof is particularly preferable.

In general formula (I), R ² represents a divalent hydrocarbon group and may further have a substituent. The hydrocarbon group may contain one or more heteroatoms selected from the group consisting of an oxygen atom, a nitrogen atom and a sulfur atom.

Examples of the substituent that can be introduced into R ² include the same substituents as those described as the substituent that can be introduced into R ¹ , and the preferred substituents are also the same.

The divalent hydrocarbon group represented by R ² is more preferably an alkylene group or a phenylene group which may have a substituent. Specific examples include a linear or branched alkylene group such as a methylene group, an ethylene group, a propylene group, a butylene group, an isopropylene group, and an isobutylene group, and a phenylene group. Moreover, as a more preferable form, what substituted the carboxyl group to the said alkylene group is mentioned.

In general formula (I), the carboxyl group that R ² has may form an alkali metal salt or an ammonium salt.

A more preferable structure of the general formula (I) is a case where R ¹ is a hydrocarbon group substituted with a carboxyl group, and R ² is a linear alkylene group or an alkylene group substituted with a carboxyl group. . Furthermore, the most preferable structure of the general formula (I) is a case where R ¹ is an alkyl group substituted with a carboxyl group, and R ² is a linear alkylene group.

  As a method for introducing the structure represented by the general formula (I) as a side chain into the polymer, for example, a monomer having a structure represented by the general formula (I) is polymerized or copolymerized by a known method. Good. Other methods include a method of reacting poly-p-aminostyrene and chloroacetic acid, and a method of hydrolyzing after reacting polychloromethylstyrene and iminodiacetonitrile. From the viewpoint of more easily controlling the introduction rate of the structure represented by the general formula (I), a method of polymerizing or copolymerizing the monomer having the structure represented by the general formula (I) by a known method is preferable. .

When the specific amino acid group-containing polymer is a copolymer, it may be a random copolymer, a block copolymer, or a graft copolymer.
The synthesis of the specific amino acid group-containing polymer is performed by, for example, polymerization initiators such as peroxides such as di-t-butyl peroxide and benzoyl peroxide, persulfates such as ammonium persulfate, and azo compounds such as azobisisobutyronitrile. It can carry out by radical polymerization using The polymerization initiator is appropriately selected depending on the polymerization method to be applied. As the polymerization method, solution polymerization, emulsion polymerization, suspension polymerization or the like is applied.

  As polymerization solvents used in the synthesis, acetone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy 2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, ethyl acetate, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, toluene, water and the like can be mentioned, but are not limited thereto Is not to be done.

  Specific examples of the monomer having the structure represented by the general formula (I) include the following compounds, but the present invention is not limited thereto.

  As a monomer which has a structure represented by general formula (I), what contains the following structures is more preferable.

  Moreover, the following structure is mentioned as a preferable structure of a coupling group with the polymer principal chain skeleton represented by Y.

  In the specific amino acid group-containing polymer, the content of the structure represented by the general formula (1) is 5 mol% or more from the viewpoint of sufficiently exerting the effect of improving the printing durability due to the interaction with the aluminum support. Preferably there is. In addition, although there is no upper limit in content of this structure, 100 mol% may be sufficient, but a preferable range is 20-80 mol%.

  As a weight average molecular weight of the specific amino acid group containing polymer which concerns on this invention, 500-1 million are preferable and 1000-500000 are more preferable.

(Other monomer components)
The specific amino acid group-containing polymer according to the present invention may be obtained by copolymerizing other monomer components for the purpose of further enhancing the interaction with the support or the interaction with the recording layer. As the other monomer component, for example, from the viewpoint of improving the adhesion to the hydrophilic treatment substrate, "monomer having an onium group", from the viewpoint of improving the adhesion to the hydrophilic treatment substrate and improving the developer solubility. From the viewpoint of improving the adhesion to the recording layer, “monomer having an acid group”, “monomer having a functional group capable of interacting with the recording layer” and the like can be mentioned.

<Monomer having an onium group>
Examples of the monomer having an onium group include, but are not limited to, monomers represented by the following general formula (A) to general formula (C).

In general formulas (A) to (C), J represents a divalent linking group. K represents an aromatic group or a substituted aromatic group. M represents a divalent linking group. Y ¹ represents a group V atom in the periodic table. Y ² represents an atom belonging to Group VI of the periodic table. Z ⁻ represents a counter anion. R ² represents a hydrogen atom, an alkyl group, or a halogen atom. R ³ , R ⁴ , R ⁵ , and R ⁷ each independently represent a hydrogen atom, an alkyl group, an aromatic group, or an aralkyl group, and these may further have a substituent. R ⁶ represents an alkylidine group or a substituted alkylidine group. R ³ and R ⁴ , R ⁶ and R ⁷ may be bonded to each other to form a ring. j, k, and m each independently represent 0 or 1. u represents an integer of 1 to 3.

Among the monomers having an onium group represented by the general formulas (A) to (C), more preferable are the following cases.
J represents -COO- or -CONH-, and K represents a phenylene group or a substituted phenylene group. The substituent introduced when K is a substituted phenylene group is preferably a hydroxyl group, a halogen atom, or an alkyl group.
M is an alkylene group and a divalent linking group having a molecular formula of C _n H _2n O, C _n H _2n S, or C _n H _{2n + 1} N. However, n represents the integer of 1-12 here.
Y ¹ represents a nitrogen atom or a phosphorus atom, and Y ² represents a sulfur atom.
Z ⁻ represents a halogen ion, PF ₆ ⁻ , BF ₄ ⁻ , or R ⁸ SO ₃ ^— .
R ² represents a hydrogen atom or an alkyl group.
R ³ , R ⁴ , R ⁵ , and R ⁷ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms or an aromatic group having 6 to 10 carbon atoms to which a substituent may be bonded. Represents a group or a C7-10 aralkyl group.
R ⁶ is preferably an alkylidine group having 1 to 10 carbon atoms or a substituted alkylidine. R ³ and R ⁴ , R ⁶ and R ⁷ may be bonded to each other to form a ring.
j, k, and m each independently represent 0 or 1, but j and k are preferably not 0 at the same time.
R ⁸ represents an alkyl group having 1 to 10 carbon atoms, an aromatic group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms to which a substituent may be bonded.

Among the monomers having an onium group represented by the general formulas (A) to (C), particularly preferred are the following cases.
K represents a phenylene group or a substituted phenylene group, and when it is a substituted phenylene group, the substituent represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
M represents an alkylene group having 1 to 2 carbon atoms or an alkylene group having 1 to 2 carbon atoms linked by an oxygen atom.
Z ⁻ represents a chlorine ion or R ⁸ SO ₃ ^— . R ² represents a hydrogen atom or a methyl group. j is 0 and k is 1. R ⁸ represents an alkyl group having 1 to 3 carbon atoms.

  Although the specific example of the monomer which has an onium group used suitably for a specific amino acid group containing polymer below is given, this invention is not limited to these.

<Monomer having an acid group>
The monomer having an acid group that is suitably used for the specific amino acid group-containing polymer will be described.
The acid group contained in the monomer having an acid group is particularly preferably a carboxylic acid group, a sulfonic acid group, or a phosphonic acid group, but is not limited thereto.

-Monomer having a carboxylic acid group-
The monomer having a carboxylic acid group is not particularly limited as long as it is a polymerizable compound having a carboxylic acid group and a polymerizable double bond in its structure.
Preferable examples of the monomer having a carboxylic acid group include compounds represented by the following general formula (1).

In General Formula (1), R ^{1 to} R ⁴ each independently represent a hydrogen atom, an alkyl group, or an organic group represented by the following General Formula (2), and at least one of R ^{1 to} R ⁴ is: It is an organic group represented by the general formula (2).
Here, from the viewpoint of copolymerizability and raw material availability when producing the specific amino acid group-containing polymer, ¹ to 2 organic groups represented by the following general formula (2) are included in R ^{1 to} R ^4. It is preferable to have one, and it is particularly preferable to have one. From the viewpoint of flexibility of the specific amino acid group-containing polymer obtained as a result of the polymerization, among R ^{1 to} R ⁴ , an organic group represented by the following general formula (2) is an alkyl group or a hydrogen atom. The hydrogen atom is particularly preferable.
For the same reason, when R ^{1 to} R ⁴ are alkyl groups, they are preferably alkyl groups having 1 to 4 carbon atoms, and particularly preferably methyl groups.

  In general formula (2), X represents a single bond, an alkylene group, an arylene group which may have a substituent, or any one of the following structural formulas (i) to (iii). From the viewpoints of polymerizability, availability, etc., a single bond, an arylene group represented by a phenylene group, or one represented by the following structural formula (i) is preferred, and an arylene group or the following structural formula (i) is preferred. Those represented by the following structural formula (i) are particularly preferred.

In structural formulas (i) to (iii), Y represents a divalent linking group, and Ar represents an arylene group which may have a substituent. Y is preferably an alkylene group having 1 to 16 carbon atoms or a single bond. Methylene (—CH ₂ —) in an alkylene group is an ether bond (—O—), a thioether bond (—S—), an ester bond (—COO—), an amide bond (—CONR—; R is a hydrogen atom or an alkyl A bond which may be substituted with a methylene group, an ether bond or an ester bond is particularly preferable.
Among such divalent linking groups, particularly preferred specific examples are listed below.

  Particularly preferable examples of the monomer having a carboxylic acid group represented by the general formula (1) are shown below, but the present invention is not limited thereto.

-Monomers having sulfonic acid groups-
The monomer having a sulfonic acid group is not particularly limited as long as it is a polymerizable compound having a sulfonic acid group and a polymerizable double bond in its structure.
Preferable specific examples of the monomer having a sulfonic acid group include 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, and 4-styrene sulfonic acid.

-Monomer having a phosphonic acid group-
The monomer having a phosphonic acid group is not particularly limited as long as it is a polymerizable compound having a phosphonic acid group and a polymerizable double bond in its structure.
Preferable specific examples of the monomer having a phosphonic acid group include acid phosphooxyethyl methacrylate, 3-chloro-2-acid phosphooxypropyl methacrylate, and acid phosphoxypolyoxyethylene glycol monomethacrylate.

<Other monomers>
Specific examples of other monomers are given below, but the present invention is not limited thereto.

  (1) N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide, o-, m- or p-hydroxystyrene, o- or m-bromo-p-hydroxysterene, o- or Acrylamides having an aromatic hydroxyl group such as m-chloro-p-hydroxyquinstyrene, o-, m- or p-hydroxyphenyl acrylate or methacrylate, methacrylamides, acrylic esters, methacrylic esters and hydroxystyrenes ;

  (2) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- [1- (3-aminosulfonyl) naphthyl] acrylamide Acrylamides such as N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) methacryl Amides, methacrylamides such as N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacrylamide, o-aminosulfonylphenyl acrylate, m-aminosulfonylphenyl Nyl acrylate, p-aminosulfonylphenyl acrylate, unsaturated sulfonamides such as acrylic esters such as 1- (3-aminosulfonylphenylnaphthyl) acrylate, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p- Unsaturated sulphonamides such as methacrylic acid esters such as aminosulfonylphenyl metatalylate and 1- (3-aminosulfonylphenylnaphthyl) methacrylate;

(3) phenylsulfonylacrylamide, which may have a substituent such as tosylacrylamide, and phenylsulfonylmethacrylamide, which may have a substituent such as tosylmethacrylamide;
(4) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate;

  (5) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, acrylic acid-2 -(Substituted) acrylic esters such as chloroethyl, 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate;

  (6) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, methacrylic acid-2 -(Substituted) methacrylate esters such as chloroethyl, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate;

  (7) Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethyl acrylamide, N-ethyl methacrylamide, N-hexyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N- Cyclohexylmethacrylamide, N-hydroxyethylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenylmethacrylamide Acrylamide or methacrylate such as N-ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide De;

  (8) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether;

(9) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate;
(10) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene;
(11) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone;
(12) Olefin such as ethylene, propylene, isobutylene, butadiene, isoprene;

(13) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc .;
(14) Lactone group-containing monomers such as pantoyl lactone (meth) acrylate, α- (meth) acryloyl-γ-butyrolactone, β- (meth) acryloyl-γ-butyrolactone;
(15) Ethylene oxide group-containing monomers such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and methoxypolyethylene glycol mono (meth) acrylate.

In the specific amino acid group-containing polymer, the content of other monomers described above is preferably 95 mol% or less, more preferably 80 mol% or less.
Among the other monomers, it is more preferable to copolymerize (4) acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group, (5) acrylic acid esters, and (6) methacrylic acid esters.

  Hereinafter, although the specific example (P-1 to P-21) of the specific amino acid group containing polymer which concerns on this invention is given, this invention is not limited to these.

  The content of the specific amino acid group-containing polymer in the intermediate layer is preferably 50 to 100% by mass and more preferably 80 to 100% by mass with respect to the total solid content constituting the intermediate layer.

(Formation of intermediate layer)
The intermediate layer according to the present invention can be provided by applying a coating solution (intermediate layer forming coating solution) in which each component of the above-described intermediate layer is dissolved onto the support described later by various methods. Although there is no restriction | limiting in particular in the method of apply | coating an intermediate | middle layer, The following method is mentioned as a typical thing.
That is, (1) a solution in which the specific amino acid group-containing polymer in the present invention is dissolved in an organic solvent such as methanol, ethanol, methyl ethyl ketone, dimethyl sulfoxide, or a mixed solvent thereof, or a mixed solvent of these organic solvent and water. Is applied on a support and dried. Or (2) supported in a solution in which the specific polymer in the present invention is dissolved in an organic solvent such as methanol, ethanol, methyl ethyl ketone, or dimethyl sulfoxide, or a mixed solvent thereof, or a mixed solvent of these organic solvent and water. Examples of the coating method include immersing the body, and then washing and drying with water or air to provide an intermediate layer.

  In the application method (1), a solution having a concentration of 0.005 to 10% by mass in total may be applied by various methods. As the coating means, any means such as bar coater coating, spin coating, spray coating, curtain coating, etc. may be used. In the coating method (2), the concentration of the solution is 0.005 to 20% by mass, preferably 0.01 to 10% by mass, and the immersion temperature is 0 to 70 ° C., preferably 5 to 60 ° C. The soaking time is 0.1 to 5 minutes, preferably 0.5 to 120 seconds.

The above intermediate layer forming coating solution includes basic substances such as ammonia, triethylamine, potassium hydroxide, inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid, and nitric acid, organic sulfonic acids such as nitrobenzene sulfonic acid, naphthalene sulfonic acid, Adjust pH with various organic acidic substances such as organic phosphonic acid such as phenylphosphonic acid, organic carboxylic acid such as benzoic acid, coumaric acid and malic acid, organic chloride such as naphthalenesulfonyl chloride, benzenesulfonyl chloride, etc., pH = 0 12, More preferably, it can also be used in the range of pH = 0-6.
In addition, a substance that absorbs ultraviolet light, visible light, infrared light, or the like may be added to the coating solution for forming an intermediate layer in order to improve the tone reproducibility of the lithographic printing plate.

The total coating amount of the intermediate layer in the present invention after drying is appropriately 1 to 100 mg / m ² , and preferably ² to 70 mg / m ² .

[Recording layer]
The infrared laser-sensitive positive recording layer having a laminated structure according to the present invention is composed of two or more layers having different constituent components, each containing a polymer having a phenolic hydroxyl group (specific phenol polymer) in the lower layer. The layer structure is not particularly limited, but in the present invention, a two-layer structure comprising an alkali-soluble lower layer containing a specific phenol polymer and an upper layer whose solubility in an alkali developer is improved by infrared laser exposure. It is preferable that it has.
Hereinafter, the recording layer having such a laminated structure as a preferred embodiment will be described.

-Lower layer-
The alkali-soluble lower layer according to the present invention is characterized by containing a specific phenol polymer. Since the phenolic hydroxyl group present in the specific phenol polymer strongly interacts with the structure represented by the general formula (I) present in the specific amino acid group-containing polymer, the adhesion between the intermediate layer and the recording layer is increased, Excellent printing durability and chemical resistance, which are the effects of the present invention, can be obtained.

[Specific phenolic polymer]
The specific phenol polymer used in the present invention is not particularly limited as long as it is a polymer compound having a phenolic hydroxyl group in the molecule, but for the solvent used in forming the upper layer described below, which is mainly responsible for image forming properties. It is preferable to select a polymer compound that is insoluble or hardly soluble. This is because when the upper layer is formed after the lower layer is formed, the lower layer and the upper layer are prevented from being mixed and the boundary is made clear. From such a viewpoint, the specific phenol polymer used in the lower layer is insoluble or difficult to dissolve in ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, alcohol solvents such as methanol, ethanol, 1-methoxy-2-propanol, and mixtures thereof. It is preferable that it is dissolved.

From the viewpoint of the type of polymer compound, the alkali-soluble resin used for the lower layer is preferably composed mainly of a different material from the alkali-soluble resin used for the upper layer. As the alkali-soluble resin suitably used for the lower layer, a copolymer containing a monomer unit having a phenolic hydroxyl group and a monomer unit containing a sulfonamide group such as N- (p-aminosulfonylphenyl) (meth) acrylamide A copolymer containing a monomer unit having a phenolic hydroxyl group and a maleimide derivative such as N-phenylmaleimide; a copolymer comprising a monomer unit having a phenolic hydroxyl group and a monomer unit having an amide structure such as (meth) acrylamide; An alkali-soluble resin having a highly polar unit such as a polymer or a polycondensation resin such as a polyamide having a phenolic hydroxyl group or a polyimide having a phenolic hydroxyl group is preferably used.
Among these, as the specific phenol resin used in the present invention, from the viewpoint of image formability as a lithographic printing plate precursor, printing durability / chemical resistance, and availability and synthesis suitability of monomer units and polymer compounds The monomer unit having a phenolic hydroxyl group and the monomer unit having a sulfonamide group are preferably a copolymer, and in particular, the monomer unit having the sulfonamide group has a structure in which a sulfonamide group is bonded to an aromatic ring. It is preferably a monomer unit represented by the following general formula (II).

In general formula (II), A represents a monovalent organic group having a polymerizable double bond, and Z represents a single bond or a divalent organic group. R ^{1 to} R ⁴ each independently represents a hydrogen atom, a halogen atom, an alkoxy group, an alkyl group, an aryl group, or a hydroxyl group, and R ⁵ represents a hydrogen atom, an alkyl group, an alkanoyl group, a carbocyclic group, or Represents a heterocyclic group.
Hereinafter, each monomer unit capable of forming such a specific phenol polymer will be described in detail.

(Monomer unit having a phenolic hydroxyl group)
The monomer unit having a phenolic hydroxyl group is not particularly limited as long as it is a monomer unit having a phenolic hydroxyl group and a polymerizable double bond, but monomers represented by the following general formulas (III-1) to (III-4) Preferably it is a unit.

In the general formulas (III-1) to (III-4), R ^{1 to} R ³ are each independently an atom or substituent selected from the group consisting of a hydrogen atom, an alkyl group, a carboxy group, and an alkoxycarboxy group. Among these, a hydrogen atom or an alkyl group such as a methyl group or an ethyl group is preferable. X represents an alkylene group which may have a substituent, and m is an integer of 0 to 8. Examples of the substituent that can be introduced into the alkylene group include the same atoms or substituents represented by R ^{1 to} R ³ . Ar is an aromatic ring group which may have a substituent. Among them, a benzene ring or a naphthalene ring is preferable, and a benzene ring is particularly preferable. Examples of the substituent that can be introduced onto Ar include the same atoms or substituents represented by R ^{1 to} R ³ . N is an integer of 1 to 3.

  A monomer unit having a phenolic hydroxyl group constitutes a structural unit having a phenolic hydroxyl group by introducing a phenolic hydroxyl group into a copolymer containing a monomer unit having no phenolic hydroxyl group as a copolymerization component by a polymer reaction. May be. As a structural unit comprised in this way, it represents with the following general formula (III-5), for example.

In the general formula ^{(III-5), R 1} ~R 3 , the general formula (III-1) has the same meaning as R ¹ to R ³ in ~ (III-4), and preferred examples are also the same.

(Monomer unit represented by general formula (II))
Next, the monomer unit represented by the general formula (II) will be described.
In general formula (II), A represents a monovalent organic group having a polymerizable double bond. Preferably, organic groups represented by the following general formulas (A-1) and (A-2) are exemplified, and among them, the organic group represented by the general formula (A-1) is particularly preferable in terms of copolymerization. preferable.

In general formulas (A-1) and (A-2), R ^{1 to} R ⁵ are each independently an atom or substituent selected from the group consisting of a hydrogen atom, an alkyl group, a carboxy group, and an alkoxycarboxy group. Represents. When R ^{1 to} R ⁵ are alkyl groups, the alkyl group may be further substituted with a carboxy group or an alkoxycarboxy group. From the viewpoint of copolymerizability and availability as a polymerizable double bond, R ^{1 to} R ⁵ may be an atom or substituent selected from a hydrogen atom, a methyl group, a carboxy group, and an alkoxycarbonylmethyl group. A hydrogen atom or a methyl group is particularly preferable.

  In the general formula (II), Z represents a single bond or a divalent organic group, and preferred divalent organic groups include (Z-1) to (Z-5) shown below.

In the above (Z-1) to (Z-5), X represents a bond selected from the group consisting of a single bond, an alkylene group, and an arylene group or a divalent organic group. Among them, an alkylene group or a single bond Preferably there is. In (Z-2) and (Z-5), R ^{a to} R ^c each independently represents an atom or substituent selected from the group consisting of a hydrogen atom, an alkyl group, and an aryl group. From the viewpoint of properties and the like, a hydrogen atom is preferable.

In the general formula (II), R ^{1 to} R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkoxy group, an alkyl group, an aryl group or a hydroxyl group, and preferably a hydrogen atom or an alkyl group. R ⁵ represents a hydrogen atom, an alkyl group, an alkanoyl group, a carbocyclic group or a heterocyclic group, and is preferably a hydrogen atom.

  Specific examples (S-1 to S-17) of those suitably used in the present invention among the monomer units represented by the general formula (II) are shown below.

(Other monomer units)
The specific phenol polymer in the present invention essentially comprises a monomer unit having a phenolic hydroxyl group and a monomer unit represented by the general formula (II). In addition to these monomer units, a third copolymer is used. You may have the structural unit derived | led-out from the other monomer unit shown below as a component. Examples of other monomer units include the compounds listed in the following (m1) to (m14), but are not limited thereto.

(M1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(M2) Alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, and glycidyl acrylate.
(M3) Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, and glycidyl methacrylate.
(M4) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide.

(M5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(M6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene, and p-acetoxystyrene.
(M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(M9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.

(M10) N-vinylpyrrolidone, acrylonitrile, methacrylonitrile and the like.
(M11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.
(M12) Maleic anhydride, itaconic anhydride, acrylic acid chloride, methacrylic acid chloride and the like.
(M13) A methacrylic acid monomer having a hetero atom bonded to the α-position. For example, compounds described in Japanese Patent Application Nos. 2001-115595 and 2001-115598.
(M14) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid and itaconic acid, and acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, and cyclic acid anhydrides Examples thereof include carboxyl group-containing monomers such as condensates of the products.

Among these copolymer components, it is preferable to use alkyl acrylate (m2), alkyl methacrylate (m3), acrylonitrile (m10) or the like in order to improve the film property.
These other monomer units as the third copolymer component are preferably contained in the specific phenol polymer in the present invention in a range of 80 mol% or less, and contained in a range of 70 mol% or less. Those are more preferred.

  Each of the above-described copolymerization components in the present invention is copolymerized by a known polymerization method, and preferred methods include radical polymerization and anionic polymerization, and radical polymerization is preferred from the viewpoint of ease of production. The reaction solvent used as necessary when performing radical polymerization can be used without limitation as long as it is a solvent that can dissolve the monomer unit, but it has a small influence on the radical polymerization reaction and is generally used. From the viewpoint of solubility of the monomer unit represented by the formula (II), ketone solvents such as acetone and methyl ethyl ketone, alcohol solvents such as methanol, ethanol, isopropyl alcohol, and 1-methoxy-2-propanol, N, N-dimethylacetamide, Amide solvents such as N, N-dimethylformamide are preferred, and N, N-dimethylacetamide is particularly preferred from the viewpoints of solubility, stability, and safety.

  In addition, as the polymerization initiator used as necessary, various thermal polymerization initiators and photopolymerization initiators can be used, but azo thermal polymerization initiators are preferable and preferable from the viewpoint of handleability and availability. As initiators, azonitrile compounds such as V-70, V-60, V-65 (all manufactured by Wako Pure Chemical Industries, Ltd.); VA-545, VA-041 (all manufactured by Wako Pure Chemical Industries, Ltd.) Azoamide compounds such as VA-080 and VA-082 (both manufactured by Wako Pure Chemical Industries, Ltd.); V-601, V-501 and VF-077 (both manufactured by Wako Pure Chemical Industries, Ltd.) And other azo compounds such as V-65 and V-601 are particularly preferable initiators.

  Furthermore, in the polymerization, the composition and molecular weight of the terminal portion of the copolymer may be controlled by using a known chain transfer agent typified by a mercapto compound or the like. Further, each monomer unit may be introduced into the copolymer in a block or random state.

The specific phenol polymer in the present invention has a monomer unit having a phenolic hydroxyl group in the range of 3 mol% or more and 60 mol% or less in the specific phenol polymer from the viewpoint of improving the adhesion with the intermediate layer and the contrast of image formation. What is contained is preferable, and what is contained in 5 mol% or more and 55 mol% or less is more preferable. From the viewpoint of improving chemical resistance, it is preferable that the monomer unit represented by the general formula (II) is contained in the specific phenol polymer in a range of 10 mol% to 45 mol%. What is contained in the range of the mol% or more and 40 mol% or less is more preferable.
Furthermore, in the specific phenol polymer in the present invention, the molar ratio between the monomer unit having a phenolic hydroxyl group and the monomer unit represented by the general formula (II) is in the range of 10:90 to 90:10. Preferably, it is in the range of 15:85 to 85:15.

  As a weight average molecular weight of the specific phenol polymer in this invention, 5,000-500,000 are preferable, 10,000-200,000 are still more preferable, 20,000-100,000 are especially preferable. If the molecular weight is too small, a sufficient coating film cannot be obtained, and if it is too large, the developability tends to be inferior.

  Below, the representative example (BP-1 to BP-12) of the specific phenol polymer in this invention is shown. The composition ratio of each copolymer represents a molar ratio, and Mw represents a weight average molecular weight.

The content of the specific phenol polymer in the lower layer component in the present invention is preferably 25 to 95% by weight, and more preferably 40 to 85% by weight.
In addition, the lower layer component according to the present invention may be used in combination with an alkali-soluble resin other than the specific phenol polymer. In that case, the ratio of the specific phenol polymer in the present invention in the total alkali-soluble resin is 40% by weight or more. Preferably there is.

[Other ingredients]
In the lower layer, other components such as a photothermal conversion substance and various additives can be used in combination with the specific phenol polymer as long as the effects of the present invention are not impaired. As these other components, those described in detail in the description of the upper layer described later can be similarly applied.

-Upper layer-
The upper layer according to the present invention is characterized in that the solubility in an alkaline developer is improved by infrared laser exposure. It is a preferable aspect that the upper layer contains an alkali-soluble resin and a photothermal conversion substance. Hereinafter, components constituting the upper layer will be sequentially described.

[Alkali-soluble resin]
The alkali-soluble resin used for the upper layer includes a homopolymer containing an acidic group in the main chain and / or side chain in the polymer, a copolymer thereof, or a mixture thereof.
Among these, those having an acidic group listed in the following (1) to (6) in the main chain and / or side chain of the polymer are preferable in terms of development resistance and solubility in an aqueous alkali solution.

(1) Phenol group (-Ar-OH)
(2) Sulfonamide group (—SO ₂ NH—R)
(3) Substituted sulfonamide acid group (hereinafter referred to as “active imide group”)
[—SO ₂ NHCOR, —SO ₂ NHSO ₂ R, —CONHSO ₂ R]
(4) Carboxylic acid group (—CO ₂ H)
(5) Sulfonic acid group (—SO ₃ H)
(6) Phosphate group (—OPO ₃ H ₂ )

  In the above (1) to (6), Ar represents a divalent aryl linking group which may have a substituent, and R represents a hydrogen atom or a hydrocarbon group which may have a substituent. .

  Among the alkali-soluble resins having an acidic group selected from the above (1) to (6), (1) an alkali-soluble resin having a phenol group, (2) a sulfonamide group, and (3) an active imide group is preferable. An alkali-soluble resin having (1) a phenol group or (2) a sulfonamide group is most preferred from the viewpoint of sufficiently ensuring solubility in an alkaline developer, development latitude, and film strength.

As alkali-soluble resin which has an acidic group chosen from said (1)-(6), the following can be mentioned, for example.
(1) Examples of the alkali-soluble resin having a phenol group include a condensation polymer of phenol and formaldehyde, a condensation polymer of m-cresol and formaldehyde, a condensation polymer of p-cresol and formaldehyde, m− / p. A novolac resin such as a condensation polymer of mixed cresol and formaldehyde, a condensation polymer of phenol and cresol (m-, p- or m- / p-mixed) and formaldehyde, and pyrogallol and acetone. Can be mentioned. Furthermore, the copolymer which copolymerized the compound which has a phenol group in a side chain can also be mentioned. Alternatively, a copolymer obtained by copolymerizing a compound having a phenol group in the side chain can also be used.

  Examples of the compound having a phenol group include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene having a phenol group.

  (2) As an alkali-soluble resin having a sulfonamide group, for example, a polymer composed of a minimum constituent unit derived from a compound having a sulfonamide group as a main constituent can be mentioned. Examples of the compound as described above include compounds having at least one sulfonamide group in which at least one hydrogen atom is bonded to a nitrogen atom and one or more polymerizable unsaturated groups in the molecule. Among them, a low molecular compound having an acryloyl group, an allyl group, or a vinyloxy group and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group in the molecule is preferable. For example, the following general formula (i) to general formula ( and a compound represented by v).

In general formulas (i) to (v), X ¹ and X ² each independently represent —O— or —NR ⁷ . R ¹ and R ⁴ each independently represents a hydrogen atom or —CH ₃ . R ² , R ⁵ , R ⁹ , R ¹² , and R ¹⁶ each independently represent a C 1-12 alkylene group, cycloalkylene group, arylene group, or aralkylene group that may have a substituent. . R ³ , R ⁷ and R ¹³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group. R ⁶ and R ¹⁷ each independently represents a C 1-12 alkyl group, cycloalkyl group, aryl group or aralkyl group which may have a substituent. R ⁸ , R ¹⁰ and R ¹⁴ each independently represent a hydrogen atom or —CH ₃ . R ¹¹ and R ¹⁵ each independently represent a C 1-12 alkylene group, cycloalkylene group, arylene group or aralkylene group which may have a single bond or a substituent. Y ¹ and Y ² each independently represent a single bond or CO. ]

  Among the compounds represented by the general formula (i) to the general formula (v), in the image recording material of the present invention, in particular, m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (P-aminosulfonylphenyl) acrylamide and the like can be preferably used.

  (3) As an alkali-soluble resin having an active imide group, for example, a polymer composed of a minimum constituent unit derived from a compound having an active imide group as a main constituent can be mentioned. Examples of the compound as described above include compounds each having one or more active imide groups represented by the following structural formula and polymerizable unsaturated groups in the molecule.

  Specifically, N- (p-toluenesulfonyl) methacrylamide, N- (p-toluenesulfonyl) acrylamide and the like can be preferably used.

(4) As an alkali-soluble resin having a carboxylic acid group, for example, a minimum structural unit derived from a compound having at least one carboxylic acid group and polymerizable unsaturated group in the molecule is used as a main constituent component. A polymer can be mentioned.
(5) As the alkali-soluble polymer having a sulfonic acid group, for example, a minimum structural unit derived from a compound having at least one sulfonic acid group and a polymerizable unsaturated group in the molecule is a main structural unit. Can be mentioned.
(6) As an alkali-soluble resin having a phosphate group, for example, a minimum structural unit derived from a compound having at least one phosphate group and a polymerizable unsaturated group in the molecule is used as a main constituent component. A polymer can be mentioned.

  The minimum structural unit having an acidic group selected from the above (1) to (6) that constitutes the alkali-soluble resin used in the image recording material of the present invention is not necessarily limited to one kind, and the same acidic group is used. It is also possible to use two or more kinds of the minimum structural units having a copolymer or two or more kinds of minimum structural units having different acidic groups.

  The copolymer preferably contains 10 mol% or more of a compound having an acidic group selected from (1) to (6) to be copolymerized, and is contained in an amount of 20 mol% or more. Those are more preferred. If it is less than 10 mol%, the development latitude tends to be insufficiently improved.

In this invention, when copolymerizing a compound and using an alkali-soluble resin as a copolymer, the other compound which does not contain the acidic group of said (1)-(6) can also be used as a compound to copolymerize. Examples of other compounds not containing an acidic group of (1) to (6) include the compounds listed in the following (m1) to (m12), but are not limited thereto. Moreover, these are suitable also as a copolymerization component of the said (C) component.
(M1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(M2) Alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, and glycidyl acrylate.
(M3) Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, and glycidyl methacrylate.
(M4) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide.

(M5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(M6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene.
(M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(M9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.
(M10) N-vinylpyrrolidone, acrylonitrile, methacrylonitrile and the like.
(M11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.
(M12) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic acid.

  The alkali-soluble resin preferably has a phenolic hydroxyl group from the viewpoint of excellent image-forming properties when exposed to infrared laser or the like. For example, a phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- Preferred are novolak resins such as / p-mixed cresol formaldehyde resin and phenol / cresol (m-, p-, or m- / p-mixed) mixed formaldehyde resin and pyrogallol acetone resin.

  Further, as an alkali-soluble resin having a phenolic hydroxyl group, as described in US Pat. No. 4,123,279, a carbon number of 3 such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin is used. And a condensation polymer of phenol and formaldehyde having an alkyl group of ˜8 as a substituent.

  The alkali-soluble resin preferably has a weight average molecular weight of 500 or more from the viewpoint of image forming properties, and more preferably 1,000 to 700,000. The number average molecular weight is preferably 500 or more, and more preferably 750 to 650,000. The dispersity (weight average molecular weight / number average molecular weight) is preferably 1.1 to 10.

  Moreover, these alkali-soluble resins may be used alone or in combination of two or more. In the case of combination, it has 3 to 8 carbon atoms such as a condensation polymer of t-butylphenol and formaldehyde or a condensation polymer of octylphenol and formaldehyde as described in US Pat. No. 4,123,279. A polycondensation product of phenol and formaldehyde having an alkyl group as a substituent, an alkali having a phenol structure having an electron-withdrawing group on an aromatic ring described in JP-A-2000-241972 previously filed by the present inventors A soluble resin or the like may be used in combination.

  The content of the alkali-soluble resin in the upper layer is preferably 30 to 98% by mass, more preferably 40 to 95% by mass in the total solid content of the upper layer. Within this range, durability, sensitivity, and image formability are all good, which is preferable.

[Photothermal conversion material]
As a photothermal conversion substance, any substance that absorbs light energy radiation and generates heat can be used without any limitation in the absorption wavelength range, but from the viewpoint of compatibility with an easily available high-power laser, Preferred examples include infrared absorbing dyes or pigments having an absorption maximum at a wavelength of 760 nm to 1200 nm.

  As the dye, commercially available dyes, for example, known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, oxonol dyes And dyes such as diimonium dyes, aminium dyes, and croconium dyes.

  Examples of preferable dyes include cyanine dyes described in, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, and the like. Methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, JP-A-58-112793, JP-A-58- Naphthoquinone dyes described in JP-A-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc. Examples thereof include squarylium dyes described in JP-A-58-112792, and cyanine dyes described in British Patent 434,875.

  In addition, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also suitable. ) Pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, JP-A-58-220143, JP-A-59- No. 41363, No. 59-84248, No. 59-84249, No. 59-146063, No. 59-146061, and Pyryllium compounds described in JP-A-59-216146. Cyanine dyes, pentamethine thiopyrylium salts described in U.S. Pat. No. 4,283,475, etc., and Japanese Patent Publication No. 5-13514, 5-19 Pyrylium compounds Nos disclosed in Japanese 02 is also preferably used.

  Another example of a preferable dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).

  Particularly preferred among these dyes are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes. Furthermore, the dyes represented by the following general formulas (a) to (e) are preferable because they are excellent in photothermal conversion efficiency, and the cyanine dyes represented by the following general formula (a) are used in the image recording material of the present invention. In this case, it is most preferable because it gives a high interaction with the alkali-soluble resin and is excellent in stability and economy.

In formula (a), X ¹ represents a hydrogen atom, a halogen atom, -NPh _2, X ² -L ¹ or a group shown below. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or a carbon atom having 1 to 12 carbon atoms including a hetero atom. Indicates a hydrogen group. Here, the hetero atom represents N, S, O, a halogen atom, or Se.
L ¹ may be ionized as shown below, for example.

In the above formula, Xa ^- has Za described later ^- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the photosensitive layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring or It is particularly preferable that a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Za ⁻ represents a counter anion. However, Za ⁻ is not necessary when the cyanine dye represented by formula (a) has an anionic substituent in its structure and charge neutralization is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, a hexagonal salt, in view of storage stability of the photosensitive layer coating solution. Fluorophosphate ions and aryl sulfonate ions.

  Specific examples of the cyanine dye represented by formula (a) that can be preferably used in the present invention include those exemplified below, and paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. And those described in paragraph numbers [0012] to [0038] of JP-A No. 2002-40638 and paragraph numbers [0012] to [0023] of JP-A No. 2002-23360.

In the general formula (b), L represents a methine chain having 7 or more conjugated carbon atoms, the methine chain may have a substituent, and the substituents may be bonded to each other to form a ring structure. Good. Zb ⁺ represents a counter cation. Preferred counter cations include ammonium, iodonium, sulfonium, phosphonium, pyridinium, alkali metal cations (Na ⁺ , K ⁺ , Li ⁺ ) and the like. R ^{9 to} R ¹⁴ and R ^{15 to} R ²⁰ are each independently a hydrogen atom or halogen atom, cyano group, alkyl group, aryl group, alkenyl group, alkynyl group, carbonyl group, thio group, sulfonyl group, sulfinyl group, oxy group Or a substituent selected from amino groups, or a combination of two or three of these, and may be bonded to each other to form a ring structure. Here, in the general formula (b), those in which L represents a methine chain having 7 conjugated carbon atoms and those in which R ^{9 to} R ¹⁴ and R ^{15 to} R ²⁰ all represent hydrogen atoms are easily available. From the viewpoint of the effect.

  Specific examples of the dye represented by formula (b) that can be suitably used in the present invention include those exemplified below.

In general formula (c), Y ³ and Y ⁴ each represent an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom. M represents a methine chain having 5 or more conjugated carbon atoms. R ^{21 to} R ²⁴ and R ^{25 to} R ²⁸ may be the same or different, and are each a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a carbonyl group, a thiol group, Represents a group, a sulfonyl group, a sulfinyl group, an oxy group, or an amino group. Further, wherein Za ^- include a counter anion, Za in the general formula (a) ^- it is synonymous.

  In the present invention, specific examples of the dye represented by formula (c) that can be suitably used include those exemplified below.

In the general formula (d), R ²⁹ to R ³¹ each independently represent a hydrogen atom, an alkyl group, or an aryl group. R ³³ and R ³⁴ each independently represents an alkyl group, a substituted oxy group, or a halogen atom. n and m each independently represents an integer of 0 to 4. R ²⁹ and R ³⁰ , or R ³¹ and R ³² may be bonded to each other to form a ring, and R ²⁹ and / or R ³⁰ is R ³³ and R ³¹ and / or R ³² is R ³⁴ A ring may be bonded to each other, and when a plurality of R ³³ or R ³⁴ are present, R ³³ or R ³⁴ may be bonded to each other to form a ring. X ² and X ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group, and at least one of X ² and X ³ represents a hydrogen atom or an alkyl group. Q is a trimethine group or a pentamethine group which may have a substituent, and may form a ring structure together with a divalent organic group. Zc ⁻ represents a counter anion and has the same meaning as Za ⁻ in the general formula (a).

  In the present invention, specific examples of the dye represented by the general formula (d) that can be suitably used include those exemplified below.

In the general formula (e), R ^{35 to} R ⁵⁰ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a hydroxyl group, or a carbonyl group that may have a substituent. Group, thio group, sulfonyl group, sulfinyl group, oxy group, amino group, and onium salt structure. M represents two hydrogen atoms or metal atoms, a halometal group, and an oxymetal group, and the metal atoms contained therein include IA, IIA, IIIB, IVB group atoms of the periodic table, first, second, second Three-period transition metals and lanthanoid elements can be mentioned, among which copper, magnesium, iron, zinc, cobalt, aluminum, titanium, and vanadium are preferable.

  In the present invention, specific examples of the dye represented by formula (e) that can be suitably used include those exemplified below.

  Examples of pigments used as infrared absorbers in the present invention include commercially available pigments and Color Index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology”. (CMC Publishing, published in 1986) and “Printing Ink Technology”, published by CMC Publishing, published in 1984).

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, 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 In addition, quinophthalone 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 pigments, carbon black is preferable.

  These pigments may be used without surface treatment, or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Applications of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. When the particle diameter of the pigment is less than 0.01 μm, it is not preferable from the viewpoint of stability of the dispersion in the image recording layer coating solution, and when it exceeds 10 μm, it is not preferable from the viewpoint of uniformity of the image recording layer.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

  These photothermal conversion pigments or dyes are 0.01 to 50% by mass, preferably 0.1 to 40% by mass, particularly preferably 0.5 to 30%, based on the total solid content constituting the upper layer. It can be added at a rate of mass%.

[Other ingredients]
In addition to the above-described components, various additives can be added to the upper layer as necessary as long as the effects of the present invention are not impaired.

  Useful additives include, for example, onium salts, aromatic sulfone compounds, aromatic sulfonic acid ester compounds, polyfunctional amine compounds, etc., and the ability to inhibit dissolution of alkaline water-soluble polymers (alkali-soluble resins) in a developer. The so-called dissolution inhibitor that improves the viscosity can be mentioned. Among them, it is possible to use together a substance that is thermally decomposable, such as an onium salt, an o-quinonediazide compound, and a sulfonic acid alkyl ester, and that substantially reduces the solubility of the alkali-soluble resin when not decomposed. It is preferable from the viewpoint of improving the dissolution inhibiting property. As the decomposable dissolution inhibitor, onium salts such as diazonium salts, iodonium salts, sulfonium salts, ammonium salts, and o-quinonediazide compounds are preferable, and diazonium salts, iodonium salts, and onium salts of sulfonium salts are more preferable.

Preferred examples of the onium salt used in the present invention include S.P. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Bal et al, Polymer, 21, 423 (1980), diazonium salts described in JP-A-5-158230, US Pat. Nos. 4,069,055, 4,069,056, Ammonium salts described in JP-A-3-140140; C. Necker et al, Macromolecules, 17, 2468 (1984), C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055 and 4,069,056, phosphonium salts described in J. Am. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent No. 104,143, US Pat. No. 5,041,358, US Pat. No. 4,491,628, Japanese Patent Laid-Open No. 2-150848, Japanese Patent Laid-Open No. Iodonium salts described in JP-A-2-296514, J. Org. V. Crivello et al, Polymer J. et al. 17, 73 (1985), J. Am. V. Crivello et al. J. et al. Org. Chem. 43, 3055 (1978); R. Watt et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 22, 1789 (1984), J. Am. V. Crivello et al, Polymer Bull. 14, 279 (1985), J. Am. V. Crivello et al, Macromolecules, 14 (5), 1141 (1981), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. 17, 2877 (1979), European Patent Nos. 370,693, 233,567, 297,443, 297,442, U.S. Pat. No. 4,933,377. No. 3,902,114, No. 5,041,358, No. 4,491,628, No. 4,760,013, No. 4,734,444 No. 2,833,827, German Patent 2,904,626, 3,604,580, 3,604,581 Salt, J.M. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988).
Among these onium salts, diazonium salts are particularly preferable from the viewpoints of dissolution inhibiting ability and thermal decomposability. In particular, the diazonium salt represented by the general formula (I) described in JP-A No. 5-158230 and the diazonium salt represented by the general formula (1) described in JP-A No. 11-143064 are preferable. The diazonium salt represented by the general formula (1) described in JP-A-11-143064 having a small absorption wavelength is most preferable.

  The counter ion of the onium salt includes tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfone Examples include acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and paratoluenesulfonic acid. Of these, particularly preferred are alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid.

  Suitable quinonediazides include o-quinonediazide compounds. The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group, which increases alkali solubility by thermal decomposition, and compounds having various structures can be used. That is, o-quinonediazide helps the solubility of the sensitive material system by both the effect of losing the ability to suppress the dissolution of the binder due to thermal decomposition and the change of o-quinonediazide itself into an alkali-soluble substance. Examples of the o-quinonediazide compound used in the present invention include J. The compounds described in pages 339 to 352 of “Light-sensitive systems” by John Coley (John Wiley & Sons. Inc.) can be used, and in particular, o-quinonediazide reacted with various aromatic polyhydroxy compounds or aromatic amino compounds. The sulfonic acid esters or sulfonic acid amides are preferred. Further, benzoquinone (1,2) -diazidosulfonic acid chloride or naphthoquinone- (1,2) -diazide-5-sulfonic acid chloride and pyrogallol-acetone resin as described in JP-B-43-28403 Esters of benzoquinone- (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazide- described in US Pat. Nos. 3,046,120 and 3,188,210 Esters of 5-sulfonic acid chloride and phenol-formaldehyde resin are also preferably used.

  Further, an ester of naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and phenol formaldehyde resin or cresol-formaldehyde resin, naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and pyrogallol-acetone resin Similarly, the esters are also preferably used. Other useful o-quinonediazide compounds are reported and known in numerous patents. For example, JP-A-47-5303, JP-A-48-63802, JP-A-48-63803, JP-A-48-96575, JP-A-49-38701, JP-A-48-13354, Japanese Patent Publication Nos. 41-11222, 45-9610, 49-17478, U.S. Pat. Nos. 2,797,213, 3,454,400, and 3,544,323. No. 3,573,917, No. 3,674,495, No. 3,785,825, British Patent No. 1,227,602, No. 1,251,345, No. 1 No. 1,267,005, No. 1,329,888, No. 1,330,932, German Patent No. 854,890, and the like.

  The addition amount of the onium salt and / or o-quinonediazide compound which is a degradable dissolution inhibitor is preferably 1 to 10% by mass, more preferably 1 to 5% by mass, based on the total solid content constituting the upper layer. Especially preferably, it is the range of 1-2 mass%. These compounds can be used alone, but may be used as a mixture of several kinds.

  The addition amount of additives other than the o-quinonediazide compound is preferably 0.1 to 5% by mass, more preferably 0.1 to 2% by mass, and particularly preferably 0.1% by mass, based on the total solid content constituting the upper layer. 1 to 1.5% by mass. The additive and binder according to the present invention are preferably contained in the same layer.

  Further, a dissolution inhibitor having no decomposability may be used in combination, and preferred dissolution inhibitors include sulfonate esters, phosphate esters, and aromatic carboxylic acids described in detail in JP-A-10-268512. Esters, aromatic disulfones, carboxylic anhydrides, aromatic ketones, aromatic aldehydes, aromatic amines, aromatic ethers, etc., as well as lactone skeletons described in detail in JP-A-11-190903, N, N- Examples thereof include an acid color-forming dye having a diarylamide skeleton and a diarylmethylimino skeleton, which also serves as a colorant, and nonionic surfactants described in detail in JP-A No. 2000-105454.

Furthermore, for the purpose of improving sensitivity, cyclic acid anhydrides, phenols, and organic acids can be used in combination as additives. Further, surfactants, image colorants, plasticizers, and the like, which will be described later, can also be mentioned as commonly used additives.
Examples of cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and 3,6-endooxy-Δ ⁴ -tetrahydrophthalic anhydride described in US Pat. No. 4,115,128. Tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. As phenols, bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4′-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ′, 4 '' -Trihydroxytriphenylmethane, 4,4 ′, 3 ″, 4 ″ -tetrahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane and the like. Furthermore, examples of organic acids include sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphate esters, and carboxylic acids described in JP-A-60-88942 and JP-A-2-96755. Is mentioned.
The proportion of the cyclic acid anhydride, phenols and organic acids in the recording layer is preferably 0.05 to 20% by mass, more preferably 0.1 to 15%, based on the total solid content constituting the upper layer. % By mass, particularly preferably 0.1 to 10% by mass.

  In addition to these, epoxy compounds, vinyl ethers, and further, phenol compounds having a hydroxymethyl group, phenol compounds having an alkoxymethyl group described in JP-A-8-276558, and the inventors previously proposed. A crosslinkable compound having an alkali dissolution inhibiting action described in JP-A-11-160860 can be appropriately added depending on the purpose.

In forming the recording layer according to the present invention, it is described in Japanese Patent Application Laid-Open No. 62-251740 and Japanese Patent Application Laid-Open No. 3-208514 in order to widen the processing stability to the developing conditions in the coating solution. Nonionic surfactants, amphoteric surfactants as described in JP-A-59-121044, JP-A-4-13149, and siloxane compounds as described in EP950517 A fluorine-containing monomer copolymer as described in JP-A-11-288093 can be added.
Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like. Specific examples of the double-sided activator include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-N, N-betaine. Type (for example, trade name “Amorgen K” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).
The siloxane compound is preferably a block copolymer of dimethylsiloxane and polyalkylene oxide. Specific examples include DBE-224, DBE-621, DBE-712, DBP-732, DBP-534, manufactured by Chisso Corporation. And polyalkylene oxide-modified silicones such as Tego Glide 100 manufactured by Tego, Germany.
The proportion of the nonionic surfactant and the amphoteric surfactant in the photosensitive composition is preferably 0.05 to 15% by mass, more preferably 0.1 to 0.1% by mass with respect to the total solid content constituting the upper layer. 5% by mass.

Further, a printing-out agent for obtaining a visible image immediately after heating by exposure, or a dye or pigment as an image colorant can be added.
Typical examples of the printing-out agent include a combination of a compound that releases an acid by heating by exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, combinations of o-naphthoquinonediazide-4-sulfonic acid halides and salt-forming organic dyes described in JP-A-50-36209 and JP-A-53-8128, 36223, 54-74728, 60-3626, 61-143748, 61-151644, and 63-58440, and trihalomethyl compounds and salt-forming organic dyes Can be mentioned. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear printout images.

  As the image colorant, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Examples of suitable dyes including salt-forming organic dyes include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (oriental chemical industry) Manufactured by Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), and the like. The dyes described in JP-A-62-293247 are particularly preferred. These dyes can be added to the recording layer in a proportion of 0.01 to 10% by mass, preferably 0.1 to 3% by mass, based on the total solid content constituting the upper layer.

  Furthermore, a plasticizer is added to the upper layer as needed to impart flexibility of the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid These oligomers and polymers are used.

[Formation of recording layer]
In order to form the recording layer according to the present invention, a lower layer coating solution in which the lower layer component is dissolved in a solvent and an upper layer coating solution in which the upper layer component is dissolved in a solvent may be coated on a suitable support. The specific phenol polymer which is a characteristic component of the present invention needs to be contained in the lower layer as described above, but may be contained in both the lower layer and the upper layer.

In the lithographic printing plate precursor according to the invention, a backcoat layer, a protective layer, and the like described later can be formed in the same manner in addition to the recording layer, depending on the purpose.
Solvents used here include 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, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and toluene. It is not limited. These solvents are used alone or in combination.
The concentration of each recording layer component (total solid content including additives) in the solvent is preferably 1 to 50% by mass.

  Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

The coating amount (solid content) of the lower layer component on the intermediate layer obtained after coating and drying is 0.05 to 1.5 g / in terms of printing durability, chemical resistance, image reproducibility, and sensitivity improvement. it is preferably in the range of m ^2, and more preferably from 0.1 to 1.0 g / m ^2.
The coating amount of the upper layer component after drying is preferably in the range of 0.05 to 3.5 g / m ² , more preferably 0.1 to 1.5 g, from the viewpoint of improving printing durability and sensitivity. / M ² range.
The lower layer and the coating amount after drying of the combined upper layer, preferably in the range of 0.5 to 5.0 g / m ^2, more preferably in the range of 1.0 to 3.0 g / m ^2.

In principle, the lower layer and the upper layer are preferably formed by separating the two layers.
As a method for forming the two layers separately, for example, a method using a difference in solvent solubility between a component contained in the lower layer and a component contained in the upper layer, or after applying the upper layer, a solvent is rapidly used. For example, a method of drying and removing.

  In the lower layer and upper layer coating solutions according to the present invention, a surfactant for improving the coating property, for example, a fluorine-based surfactant as described in JP-A-62-170950 is added. can do. A preferable addition amount is 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass in the total solid content of each recording layer.

(Support)
The support used in the lithographic printing plate precursor according to the present invention is a dimensionally stable plate-like material, and is not particularly limited as long as it satisfies physical properties such as required strength and flexibility. , Paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), 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 a metal as described above is laminated or vapor-deposited.
As the support that can be applied to the present invention, a polyester film or an aluminum plate is preferable. Among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is at most 10% by mass. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements.
Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and particularly preferably 0.2 mm to 0.3 mm.

  Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired. The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of 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. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used. The roughened aluminum plate is subjected to alkali etching treatment and neutralization treatment as necessary, and then subjected to anodization treatment if desired in order to enhance the water retention and wear resistance of the surface. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, phosphoric 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 electrolyte.

The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, 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 5 minutes are suitable. When the amount of the anodized film is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image part of the lithographic printing plate is easily damaged, and the ink adheres to the damaged part during printing. So-called “scratch dirt” is likely to occur. After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. The hydrophilization treatment used in the present invention is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are alkali metal silicate (such as aqueous sodium silicate) methods. In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, it is disclosed in potassium fluoride zirconate disclosed in Japanese Patent Publication No. 36-22063 and US Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid is used.

(Back coat layer)
A back coat layer is provided on the back surface of the support of the lithographic printing plate precursor according to the invention, if necessary. Such a back coat layer comprises a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. A coating layer is preferably used. Among these coating layers, silicon alkoxy compounds such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , and Si (OC ₄ H ₉ ) ₄ are available at a low price. The coating layer of the metal oxide obtained therefrom is particularly preferable because of its excellent developer resistance.

〔exposure〕
As the exposure conditions for the lithographic printing plate precursor according to the present invention produced as described above, it is preferable that the exposure energy density is larger than 5 kW to 10 kW / cm ² in terms of effective use of heat in image formation. Desired sensitivity can be obtained by exposure under conditions. The higher the exposure energy density, the more advantageous in terms of sensitivity. However, for example, when the exposure power density exceeds 50 kW / cm ² , ablation is likely to occur, which may cause adverse effects such as contamination of the optical system.
With regard to the exposure wavelength, at present, it is preferable to use the near-infrared to infrared region from the viewpoint of economics of a high-power laser. As the exposure light source, a solid laser or a semiconductor laser is preferable from the viewpoint of economy and light source life.

〔developing〕
A conventionally known alkaline aqueous solution can be used as a developer and a replenisher for a lithographic printing plate precursor.
For example, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, Examples include inorganic alkali salts such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also used. These alkali agents are used alone or in combination of two or more.
Among these alkali agents, particularly preferred developers are aqueous silicate solutions such as sodium silicate and potassium silicate. The reason is that the developability can be adjusted by the ratio and concentration of silicon oxide SiO ₂ and alkali metal oxide M ₂ O, which are silicate components. For example, Japanese Patent Application Laid-Open No. 54-62004, Alkali metal silicates as described in JP-B-57-7427 are effectively used.

Furthermore, when developing using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than that of the developer is added to the developer so that the developer in the developer tank is not changed for a long time. It is known that the PS version can be processed. This replenishment method is also preferably applied in the present invention. Various surfactants and organic solvents can be added to the developer and replenisher as necessary for the purpose of promoting and suppressing developability, dispersing development residue, and improving ink affinity of the printing plate image area.
Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. If necessary, the developer and replenisher may contain reducing agents such as hydroquinone, resorcin, sulfurous acid, bisulfite, and other inorganic acids such as sodium salts and potassium salts, organic carboxylic acids, antifoaming agents, and hard water softeners. It can also be added.
The printing plate developed using the developer and the replenisher is post-treated with a desensitizing solution containing washing water, a rinsing solution containing a surfactant or the like, gum arabic or a starch derivative. As the post-treatment when the image recording material of the present invention is used as a lithographic printing plate, these treatments can be used in various combinations.

  In recent years, automatic developing machines for printing plates have been widely used in the plate making and printing industries in order to rationalize and standardize plate making operations. This automatic developing machine is generally composed of a developing unit and a post-processing unit, and includes an apparatus for transporting the printing plate, each processing liquid tank and a spray device, and each pumped up by a pump while transporting the exposed printing plate horizontally. The processing liquid is sprayed from the spray nozzle and developed. In addition, recently, a method is also known in which a printing plate is dipped and conveyed by a submerged guide roll or the like in a processing liquid tank filled with the processing liquid. In such automatic processing, each processing solution can be processed while being supplemented with a replenisher according to the processing amount, operating time, and the like. In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.

  In the lithographic printing plate precursor to which the present invention is applied, an image portion unnecessary for the lithographic printing plate obtained by image exposure, development, washing and / or rinsing and / or gumming (for example, a film of an original film) If there is an edge mark or the like, the unnecessary image portion is erased. Such erasing is preferably performed by applying an erasing solution as described in, for example, Japanese Patent Publication No. 2-13293 to an unnecessary image portion, leaving it for a predetermined time, and then washing with water. As described in JP-A-59-174842, a method of developing after irradiating an unnecessary image portion with an actinic ray guided by an optical fiber can also be used.

The lithographic printing plate obtained as described above can be subjected to a printing process after applying a desensitized gum if desired. However, if it is desired to obtain a lithographic printing plate with a higher printing durability, it is desired. The burning process is performed.
In the case of burning a lithographic printing plate, before burning, an adjustment as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859, JP-A-61-159655 is used. It is preferable to treat with a surface liquid.
As its method, with a sponge or absorbent cotton soaked with the surface-adjusting liquid, it is applied onto a lithographic printing plate, or a method in which the printing plate is immersed and applied in a vat filled with the surface-adjusting liquid, Application by an automatic coater is applied. Further, it is more preferable to make the coating amount uniform with a squeegee or a squeegee roller after coating.

In general, the amount of surface-adjusting solution applied is suitably 0.03 to 0.8 g / m ² (dry mass). The lithographic printing plate coated with the surface-adjusting solution is dried if necessary, and then heated to a high temperature with a burning processor (for example, burning processor “BP-1300” sold by Fuji Photo Film Co., Ltd.). The In this case, the heating temperature and time are in the range of 180 to 300 ° C. and preferably in the range of 1 to 20 minutes, although depending on the type of components forming the image.

  The lithographic printing plate that has been burned can be subjected to conventional treatments such as washing and gumming as needed, but a surface-conditioning solution containing a water-soluble polymer compound is used. In such a case, a so-called desensitizing treatment such as gumming can be omitted. The planographic printing plate obtained by such processing is applied to an offset printing machine or the like and used for printing a large number of sheets.

EXAMPLES Hereinafter, although this invention is demonstrated according to an Example, the scope of the present invention is not limited to these Examples.
[Examples 1 to 3, Comparative Examples 1 and 2]
(Production of support)
<Aluminum plate>
Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.025 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: It contains 0.03% by mass, and the balance is prepared by using an aluminum alloy of Al and inevitable impurities. After the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm is obtained by a DC casting method. Produced. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, it was kept soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing using a continuous annealing machine at 500 degreeC, it finished by cold rolling to 0.24 mm in thickness, and obtained the aluminum plate of JIS1050 material. The obtained aluminum had an average crystal grain size with a minor axis of 50 μm and a major axis of 300 μm. After making this aluminum plate width 1030mm, it used for the surface treatment shown below.

<Surface treatment>
In the surface treatment, the following various treatments (a) to (k) were continuously performed. In addition, after each process and water washing, the liquid was drained with the nip roller.
(A) Mechanical surface roughening treatment While supplying a suspension of a polishing agent (pumice) having a specific gravity of 1.12 and water as a polishing slurry liquid to the surface of the aluminum plate, mechanical roughening is performed by a rotating nylon brush. Surface treatment was performed. The average particle size of the abrasive was 30 μm, and the maximum particle size was 100 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 45 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment The aluminum plate obtained above was subjected to an etching treatment by spraying using an aqueous solution having a caustic soda concentration of 2.6% by mass, an aluminum ion concentration of 6.5% by mass and a temperature of 70 ° C. / M ² dissolved. Then, water washing by spraying was performed.

(C) Desmutting treatment The desmutting treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by mass of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut treatment was a waste liquid from a process of performing an electrochemical surface roughening treatment using alternating current in a nitric acid aqueous solution.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 10.5 g / L aqueous solution of nitric acid (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions) at a liquid temperature of 50 ° C. AC power supply waveform is 0.8 msec until the current value reaches the peak from zero, duty ratio is 1: 1, and trapezoidal rectangular wave alternating current is used to perform electrochemical surface roughening treatment with the carbon electrode as the counter electrode. went. Ferrite was used for the auxiliary anode.
The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Then, water washing by spraying was performed.

(E) Alkaline etching treatment The aluminum plate was subjected to etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass to dissolve the aluminum plate by 0.50 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.

(F) Desmut treatment Desmut treatment was performed by spraying with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used in the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in the nitric acid aqueous solution.

(G) Electrochemical roughening treatment An electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 5.0 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform is subjected to electrochemical surface roughening using a carbon electrode as a counter electrode, using a trapezoidal trapezoidal wave alternating current with a time until the current value reaches a peak from zero for 0.8 msec, a duty ratio of 1: 1. went. Ferrite was used for the auxiliary anode.
The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. Then, water washing by spraying was performed.

(H) Alkaline etching treatment The aluminum plate was subjected to an etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, and the aluminum plate was dissolved by 0.15 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.

(I) Desmutting treatment A desmutting treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.

(J) Anodizing treatment Anodizing treatment is performed using an anodizing apparatus (first and second electrolysis section length 6 m, first and second feeding section length 3 m, first and second feeding section length 2.4 m each). It was. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 50 g / L (containing 0.5 mass% of aluminum ions) and a temperature of 20 ° C. Then, water washing by spraying was performed. The final oxide film amount was 2.7 g / m ² .

(K) Alkali metal silicate treatment An aluminum support obtained by anodizing treatment was alkali-treated by immersing it in a treatment tank of a 2.0 mass% aqueous solution of No. 3 sodium silicate at a temperature of 50 ° C for 10 seconds. Metal silicate treatment (silicate treatment) was performed. Thereafter, washing with water using well water was performed to obtain a support subjected to a surface silicate hydrophilization treatment. On the aluminum support after the alkali metal silicate treatment obtained as described above, an intermediate layer coating solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form an intermediate layer. The coating amount of the intermediate layer after drying was 9 mg / m ² .

<Interlayer coating solution composition>
・ Undercoat layer polymer 0.3 g shown in Table 1
・ Methanol 100g
・ Water 1g

(Formation of laminated recording layer)
The lower layer coating solution 1 having the following composition was coated on the obtained intermediate layer coated substrate with a bar coater so that the coating amount after drying was 0.85 g / m ² , and then dried at 160 ° C. for 44 seconds, Immediately, the substrate was cooled with cold air of 17 to 20 ° C. until the temperature of the support became 35 ° C.
Thereafter, the coating liquid 1 for the upper layer having the following composition was coated with a bar coater so that the coating amount after drying was 0.22 g / m ² , dried at 148 ° C. for 25 seconds, and further slowly cooled with air at 20 to 26 ° C. Then, a lithographic printing plate precursor was prepared.

<Lower layer coating solution 1>
-2.133 g of the polymer for the lower layer described in Table 1 below
・ Cyanine dye A (the following structure) 0.136 g
・ 4,4'-bishydroxyphenylsulfone 0.126g
・ Tetrahydrophthalic anhydride 0.190g
・ 0.008 g of p-toluenesulfonic acid
・ 3-Methoxy-4-diazodiphenylamine
Hexafluorophosphate 0.032g
・ The ethyl violet counter ion is changed to 6-hydroxynaphthalenesulfonic acid 0.0781 g
・ Polymer 1 (the following structure) 0.035g
・ Methyl ethyl ketone 25.41g
・ 1-methoxy-2-propanol 12.97g
・ Γ-butyrolactone 13.18g

<Upper layer coating solution 1>
・ M, p-cresol novolak 0.348g
(M / p ratio = 6/4, weight average molecular weight 4700,
Contains 0.8% by mass of unreacted cresol)
-Polymer 3 (the following structure MEK 30% solution) 0.1403g
・ Cyanine dye A (the above structure) 0.0192 g
・ Polymer 1 (the above structure) 0.015 g
-Polymer 2 (the following structure) 0.00328g
1- (4-Methylbenzyl) -1-phenylpiperidinium 5-benzoyl-4-hydroxy
2-methoxybenzenesulfonate 0.004g
・ Surfactant (polyoxyethylene sorbite fatty acid ester HLB8.5, GO-4 manufactured by Nikko Chemicals Co., Ltd.) 0.008 g
・ Methyl ethyl ketone 6.79g
・ 1-methoxy-2-propanol 13.07 g

[Evaluation of planographic printing plate precursor]
(Evaluation of printing durability)
The lithographic printing plate precursors of Examples 1 to 3 and Comparative Examples 1 and 2 were changed in exposure energy using a Trendsetter VFS manufactured by Creo, and a test pattern was drawn in an image form. Thereafter, development was performed at a developing temperature of 30 ° C. using a PS processor LP940H manufactured by Fuji Photo Film Co., Ltd. charged with a developer DT-2 manufactured by Fuji Photo Film Co., Ltd. (diluted to a conductivity of 43 mS / cm). Development was performed in 12 seconds. This was continuously printed using a printer Lithron manufactured by Komori Corporation. At this time, the number of sheets that can be printed while maintaining a sufficient ink density was measured visually to evaluate the printing durability. The larger the number, the better the printing durability. The results are shown in Table 1 below.

(Evaluation of chemical resistance)
The lithographic printing plate precursors of Examples 1 to 3 and Comparative Examples 1 and 2 were exposed / developed and printed in the same manner as in the evaluation of printing durability. At this time, every time 5,000 sheets were printed, a process of wiping the plate surface with a cleaner (manufactured by Fuji Photo Film Co., Ltd., multi-cleaner) was added to evaluate chemical resistance. The larger the number, the better the chemical resistance. The results are shown in Table 1 below.

(Evaluation of non-image area dirtiness)
In the evaluation of printing durability, the stain on the blanket after printing 50,000 sheets was visually evaluated.
The evaluation criteria were A that was not soiled at all, B that was hardly soiled, and C that was markedly soiled. The results are shown in Table 1.

  The structure of the lower layer polymer (BP-C) used in Comparative Example 1 and the structure of the intermediate layer polymer used in Comparative Example 2 are shown below. The polymer for the lower layer used in the examples of the present invention is a specific amino acid group-containing polymer, the polymer for the intermediate layer is a specific phenol polymer, and each structure is described in the text.

  According to the results of Table 1 above, the lithographic printing plate precursors of Examples 1 to 3 were excellent in printing durability and chemical resistance, and had good stain resistance in non-image areas. On the other hand, the lithographic printing plate precursor of Comparative Example 1 in which the specific phenol polymer was not used as the lower layer component tended to be inferior in printing durability and chemical resistance as compared with the lithographic printing plate precursors of Examples 1 to 3. Further, the lithographic printing plate precursor of Comparative Example 2 in which the specific amino acid group-containing polymer is not used as the intermediate layer component is inferior in chemical resistance, and the stain on the non-image area is remarkably problematic. Was confirmed.

[Examples 4 to 5, Comparative Example 3]
In the production of the support of Example 1, the substrate treatment was performed in the same manner as in Example 1 except that the silicate treatment was not performed after the anodic oxidation treatment to produce a lithographic printing plate precursor support.

(Formation of laminated recording layer)
After applying the lower layer coating solution 2 having the following composition to the obtained support coated with an intermediate layer with a bar coater so that the coating amount after drying is 0.80 g / m ² , the coating is dried at 160 ° C. for 44 seconds, Immediately, the substrate was cooled with cold air of 17 to 20 ° C. until the temperature of the support became 35 ° C.
Thereafter, the upper layer coating solution 2 having the following composition was coated with a bar coater so that the coating amount after drying was 0.20 g / m ² , dried at 148 ° C. for 25 seconds, and further slowly cooled with air at 20 to 26 ° C. Then, a lithographic printing plate precursor was prepared.

<Lower layer coating solution 2>
-2.133 g of the polymer for the lower layer described in Table 1 below
・ Cyanine dye A (the above structure) 0.136 g
・ 4,4'-bishydroxyphenylsulfone 0.126g
・ Tetrahydrophthalic anhydride 0.190g
・ 0.008 g of p-toluenesulfonic acid
・ 3-Methoxy-4-diazodiphenylamine
Hexafluorophosphate 0.032g
・ The ethyl violet counter ion is changed to 6-hydroxynaphthalenesulfonic acid 0.0781 g
・ Polymer 1 (the above structure) 0.035 g
・ Methyl ethyl ketone 25.41g
・ 1-methoxy-2-propanol 12.97g
・ Γ-butyrolactone 13.18g

<Upper layer coating solution 2>
・ M, p-cresol novolak 0.348g
(M / p ratio = 6/4, weight average molecular weight 4700,
Contains 0.8% by mass of unreacted cresol)
・ Polymer 3 (said structure MEK 30% solution) 0.1403 g
・ Cyanine dye A (the above structure) 0.0192 g
・ Polymer 1 (the above structure) 0.015 g
・ Polymer 2 (the above structure) 0.00328 g
1- (4-Methylbenzyl) -1-phenylpiperidinium 5-benzoyl-4-hydroxy
2-methoxybenzenesulfonate 0.004g
・ Surfactant (polyoxyethylene sorbite fatty acid ester HLB8.5, GO-4 manufactured by Nikko Chemicals Co., Ltd.) 0.008 g
・ Methyl ethyl ketone 6.79g
・ 1-methoxy-2-propanol 13.07 g

[Evaluation of planographic printing plate precursor]
The lithographic printing plate precursors of Examples 4 to 5 and Comparative Example 3 were the same as Example 1 except that the developer was changed to Kodak Polychrome Graphics Co., Ltd. developer PD1, and the development time was changed to 25 seconds. Then, exposure, development and printing were performed. Further, printing durability, chemical resistance and non-image area stain resistance were evaluated in the same manner. The results are shown in Table 2 below.

  According to the results in Table 2 above, the planographic printing plate precursors of Examples 4 and 5 were excellent in printing durability and chemical resistance, and the stain resistance of the non-image area was also good. On the other hand, the lithographic printing plate precursor of Comparative Example 3 in which no intermediate layer was provided was inferior in chemical resistance to the lithographic printing plate precursors of Examples 4 and 5, and the non-image area was stained.

Claims (1)

On the support, an intermediate layer containing a polymer having a structure represented by the following general formula (I) in the side chain, and an infrared laser-sensitive positive recording layer having a laminate structure of at least two layers are sequentially provided. A lithographic printing plate precursor provided, wherein the layer adjacent to the intermediate layer of the recording layer contains a polymer having a phenolic hydroxyl group.

(In general formula (I), Y represents a linking group to the polymer main chain skeleton. R ¹ represents a hydrogen atom or a hydrocarbon group. R ² represents a divalent hydrocarbon group.)