JP2006184517A - Positive image recording material adaptable to heat mode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive image recording material adaptable to a heat mode, having large dissolution discrimination, excellent in development latitude, and excellent also in chemical resistance. <P>SOLUTION: The positive image recording material adaptable to a heat mode has on a support a recording layer containing a high-molecular compound which includes a structural unit represented by formula (I), wherein part or all of phenolic hydroxyl groups which the structural unit includes have been modified with a substituent having an unshared electron pair bonding site and a hydrogen atom capable of hydrogen bond, and capable of forming thermally reversible two or more hydrogen bonds, and an infrared absorbing agent. In the formula (I), R<SP>01</SP>represents an aromatic group having a hydroxyl group as a substituent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image recording material that can be used as a lithographic printing plate precursor, color proof, photoresist, and color filter, and in particular, a so-called lithographic plate that can be directly made by scanning an infrared laser based on a digital signal from a computer or the like. The present invention relates to a heat mode-compatible positive image recording material that can be used for a printing plate precursor.

  In recent years, the development of lasers has been remarkable, and in particular, solid-state lasers and semiconductor lasers having a light emitting region from the near infrared to the infrared can easily obtain high-power and small-sized ones. These lasers are very useful as an exposure light source when directly making a plate from digital data such as a computer.

  The positive recording layer includes a binder resin that is soluble in an alkaline aqueous solution and a dissolution inhibitor that substantially reduces the solubility of the binder resin by interaction with the binder resin. In addition to the binder resin and the dissolution inhibitor, the positive-type recording layer using a photothermal conversion agent such as an infrared absorbing dye that absorbs light and generates heat is preferably contained. Among these photothermal conversion agents, cyanine dyes in particular have a function as the dissolution inhibitor, and are therefore preferably used as photothermal conversion agents for positive recording layers compatible with infrared lasers.

  However, in such a positive recording layer for an infrared laser, the difference between the solubility resistance of the unexposed area (image area) with respect to the developer and the solubility of the exposed area (non-image area) under various usage conditions. (Discrimination; hereinafter referred to as dissolution discrepancy) is still not sufficient, and there is a problem that overdevelopment and poor development easily occur due to fluctuations in use conditions.

  In order to solve this problem, a technique for improving dissolution discretion is known by using a photosensitive composition (for example, see Patent Document 1) in which most of the alkali-soluble resin is formed of a novolac resin. . Due to the hydrogen bond between the phenolic hydroxyl groups of this novolak resin or the interaction with other additives contained in the photosensitive composition, solubility in the developer is suppressed in the unexposed area, and in the exposed area. Dissolving discrepancy is achieved by increasing solubility due to heat. However, in reality, the size of the dissolution disc is insufficient, and there is a problem that the development stability (development latitude) depending on use conditions is low.

  As a technique for widening the dissolution disk, there is known a photosensitive composition in which a novolak resin and a resin having a structural unit having a specific functional group are used in combination as an alkali-soluble resin (for example, Patent Documents). 2). This photosensitive composition significantly improves dissolution discretion by increasing the film density in the photosensitive layer due to strong interaction between the phenolic hydroxyl group and the specific functional group. However, since the alkali-soluble resin is poor in chemical resistance, it has low resistance to a plate cleaner used when the ink adheres during printing, and the photosensitive composition is eluted when the plate surface is wiped with the cleaner. There was a problem such as.

Further, as a photosensitive composition having high chemical resistance, an alkali-soluble resin containing a polymer having a substituent having a lone pair having a hydrogen bond and a phenolic hydroxyl group is known. (For example, refer to Patent Document 3). By using such a specific resin for the lithographic printing plate material, the chemical resistance is greatly improved, but the dissolution disc is insufficient, and there is a problem that the development stability is lowered.
European Patent Application No. 823327 JP 2000-75485 A US Pat. No. 6,506,536

An object of the present invention is to solve the conventional technical problems and achieve the following objects.
That is, an object of the present invention is to provide a heat mode compatible positive type image recording material having a large dissolution discrepancy and excellent development latitude and excellent chemical resistance.

As a result of intensive studies, the present inventors have found that the above object can be achieved by including a polymer compound having a specific structure in the recording layer of the image recording material, and have completed the present invention. .
That is, the heat mode-compatible positive image recording material of the present invention contains a structural unit represented by the following general formula (I) on the support, and a part or all of the phenolic hydroxyl groups of the structural unit are: Highly modified by a substituent having a non-covalent electron pair binding site and a hydrogen atom capable of hydrogen bonding and capable of forming two or more thermally reversible hydrogen bonds (hereinafter referred to as “specific substituent” as appropriate) It has a recording layer containing a molecular compound (hereinafter referred to as “specific polymer compound” as appropriate) and an infrared absorber.

In general formula (I), R ⁰¹ represents an aromatic group having a hydroxyl group as a substituent.

  The recording layer in the present invention may be a single layer or may have a multilayer structure composed of a plurality of layers having different constituent components. In the case of a recording layer having a multilayer structure, an embodiment in which the specific polymer compound is contained in the lower layer is preferable from the viewpoint of effects.

Although the operation of the present invention is not clear, it is presumed as follows.
The specific polymer contained in the recording layer in the present invention is a polymer compound containing a structural unit having an acetal structure as represented by the general formula (I), and has a large number of oxygen atoms in the structure. For this reason, in the unexposed area, the oxygen atom in the acetal structure strongly interacts with the specific substituent, so that it is assumed that the solubility in the developer is suppressed. Further, it is presumed that the film exhibits excellent film properties and chemical resistance due to the acetal structure present in the specific polymer compound.
On the other hand, in the exposed area, the interaction is easily released by energy such as heat, so that the solubility in an alkaline aqueous solution inherent in the specific polymer compound is expressed and it is assumed that high developability can be secured. . Further, since it has a strong interaction as described above, it is presumed that the scratch resistance, particularly the effect of suppressing the generation of scratches due to the influence of the high-concentration alkaline aqueous solution is improved, and as a result, the development latitude is expanded.

  According to the present invention, it is possible to provide a heat mode compatible positive type image recording material having a large dissolution discrepancy and excellent development latitude and excellent chemical resistance.

The heat mode-compatible positive image recording material of the present invention (hereinafter sometimes simply referred to as “image recording material”) will be described in detail below.
The image recording material of the present invention includes a structural unit represented by the following general formula (I) on a support, and a part or all of the phenolic hydroxyl group of the structural unit is a lone pair binding site and A polymer compound (specific polymer compound) having a hydrogen atom capable of hydrogen bonding and modified with a substituent (specific substituent) capable of forming two or more thermally reversible hydrogen bonds, and an infrared absorber It has the recording layer to contain.
The recording layer in the present invention is not particularly limited in its layer structure, and may be a single layer structure or a multilayer structure composed of a plurality of layers having different constituent components. When the recording layer has a multilayer structure, the specific polymer compound may be contained in any layer, but it is particularly preferred that it is contained in the lower layer from the viewpoint of effects.
First, each configuration of the lithographic printing plate precursor according to the invention having a single-layer type recording layer will be described in detail sequentially.

[Single layer recording layer]
[Specific polymer compound]
The specific polymer compound in the present invention includes a structural unit represented by the following general formula (I), and a part or all of the phenolic hydroxyl group of the structural unit is capable of hydrogen bonding with an unshared electron pair binding site. It is modified with a substituent (specific substituent) having a hydrogen atom and capable of forming two or more thermally reversible hydrogen bonds.

In general formula (I), R ⁰¹ represents an aromatic group having a hydroxyl group as a substituent.
In the specific polymer compound, part or all of the hydroxyl groups (phenolic hydroxyl groups) which R ⁰¹ has as a substituent needs to be modified with a specific substituent described in detail later.

In general formula (I), examples of the aromatic ring contained in the aromatic group represented by R ⁰¹ having a hydroxyl group as a substituent include a benzene ring, a naphthalene ring, and an anthracene ring.
The aromatic group represented by R ⁰¹ and having a hydroxyl group as a substituent may further have a substituent other than the hydroxyl group. Examples of other substituents that can be introduced include monovalent nonmetallic atomic groups excluding hydrogen. Preferred examples of the monovalent nonmetallic atomic group excluding hydrogen include a halogen atom (-F, -Br, -Cl, -I), a hydroxyl group, an alkoxy group, an aryloxy group, a mercapto group, an alkylthio group, an arylthio group, Alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy Group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkyl Sulfoxy group, arylsulfoxy group, acylthio group, acyl Mino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N'-alkylureido group, N ', N'-dialkylureido group, N'-arylureido group, N', N'- Diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N′-alkyl-N-arylureido group N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-aryl-N-arylureido group N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-alkylureido group, '- alkyl -N'- aryl -N- arylureido group,

Alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N -Aryloxycarbonylamino group, formyl group, carboxyl group and its conjugate base group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group , N, N- di arylcarbamoyl group, N- alkyl -N- arylcarbamoyl group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugate base (Hereinafter referred to as “sulfonato group”), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N , N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and its conjugate base group, N-alkylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ R , R represents an alkyl group) and its conjugate base group, N-arylsulfonylsulfur Amoiru group (-SO ₂ NHSO ₂ Ar, Ar represents an aryl group.) And a conjugated base group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ R, R represents an alkyl group.) And a conjugated base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ Ar, Ar represents an aryl group) and its conjugate base group, alkoxysilyl group (—Si (OR) ₃ , R represents an alkyl group), aryloxy Silyl group (—Si (OAr) ₃ , Ar represents an aryl group), hydroxysilyl group (—Si (OH) ₃ ) and its conjugate base group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group (Hereinafter referred to as “phosphonate group”), a dialkylphosphono group (—PO ₃ R ₂ , R represents an alkyl group). ), A diarylphosphono group (—PO ₃ Ar ₂ , Ar represents an aryl group), an alkylarylphosphono group (—PO ₃ (R) (Ar), R represents an alkyl group, and Ar represents an aryl group). ), A monoalkylphosphono group (—PO ₃ H (R), R represents an alkyl group) and a conjugate base group thereof (hereinafter referred to as “alkylphosphonate group”), a monoarylphosphono group (—PO ₃ H (Ar), Ar represents an aryl group) and its conjugate base group (hereinafter referred to as “arylphosphonate group”),

A phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as “phosphonateoxy group”), a dialkylphosphonooxy group (—OPO ₃ R ₂ , R represents an alkyl group), diarylphosphonooxy Groups (—OPO ₃ Ar ₂ , Ar represents an aryl group), alkylarylphosphonooxy groups (—OPO ₃ (R) (Ar), R represents an alkyl group, Ar represents an aryl group), monoalkyl A phosphonooxy group (—OPO ₃ H (R), R represents an alkyl group) and its conjugate base group, a monoarylphosphonooxy group (—OPO ₃ H (Ar), Ar represents an aryl group). And its conjugate base group, cyano group, nitro group, aryl group (for example, phenyl group, biphenyl group, naphthyl group, tolyl group, xylyl group, mesityl group, cumenyl group, fluoro group) Phenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, Methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group, nitrophenyl group, cyanophenyl Group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, phosphonatophenyl group, etc.), alkenyl group (for example, vinyl group, 1-propene) Group, 1-butenyl group, cinnamyl group, 2-chloro-1-ethenyl group, etc.), alkynyl group (for example, ethynyl group, 1-propynyl group, 1-butynyl group, trimethylsilylethynyl group, phenylethynyl) Group), an acyl group, and the like.

The aromatic group having a hydroxyl group as a substituent represented by R ⁰¹ is preferably a group shown below.

In the above formula, R ⁰² represents —OH. R ⁰³ represents —OH, —OCH ₃ , —Br, or —OCH ₂ —C≡CH ₃ , and R ⁰⁴ represents —Br or —NO ₂ .

In the specific polymer compound, as the structural unit represented by the general formula (I), only the structural unit having the same R ⁰¹ may be included, or a plurality of structural units having different R ⁰¹ may be included. Good. A preferred embodiment of the specific polymer compound in the present invention will be described in detail later.

As described above, the specific polymer compound has a part or all of the phenolic hydroxyl group of R ⁰¹ in the general formula (I) having a lone pair and a hydrogen atom capable of hydrogen bonding, It is modified with a substituent (specific substituent) capable of forming two or more reversibly hydrogen bonds.

  The non-shared electron pair binding site of a specific substituent refers to a site capable of forming a hydrogen bond with a hydrogen atom capable of hydrogen bonding, which will be described later. Specifically, = O, = N-, = S, = P In particular, from the viewpoint of forming a stronger hydrogen bond with a hydrogen atom, ═O and ═N— are preferable.

  The hydrogen atom capable of hydrogen bonding which the specific substituent has is an oxygen atom in the acetal structure of the structural unit represented by the general formula (I), or a hydrogen bonding bond with the lone pair binding site. This refers to an active hydrogen atom, specifically, a hydrogen atom covalently bonded to a nitrogen atom, a hydrogen atom covalently bonded to an oxygen atom, a hydrogen atom covalently bonded to a sulfur atom, or a phosphorus atom And a hydrogen atom covalently bonded to each other. Among these, from the viewpoint of forming a stronger hydrogen bond with the lone pair binding site, a hydrogen atom covalently bonded to a nitrogen atom and a hydrogen atom covalently bonded to an oxygen atom are preferable.

  In the present invention, in the film formed using the specific polymer compound, the oxygen atom in the acetal structure of the structural unit represented by the general formula (I) or the above-mentioned lone pair binding site A hydrogen atom capable of hydrogen bonding forms a thermally reversible hydrogen bond. In the case where the hydrogen bond is formed between the specific substituents, the hydrogen bond is not formed between the sites in the same specific substituent, but another specific substituent existing in the film. Formed between.

  As described above, the specific substituent in the present invention forms a hydrogen bond with the oxygen atom in the acetal structure of the structural unit represented by the general formula (I) or the lone pair binding site. Therefore, it is considered that a stable interaction is formed in which no rotational movement of molecules occurs. Further, since this hydrogen bond is thermally reversible, it is easily released by laser exposure or the like during image formation, and the exposed portion (non-image portion) is removed by development.

Preferred specific examples of the specific substituent in the present invention are shown below. In specific examples, R ^1a , R ^2a , R ^3a , and R ^4a each independently represent hydrogen or an alkyl group, and Y represents a derivative from a diisocyanate represented by Y ′ (NCO) _2. , R ^5a represents a residue of a phenolic hydroxyl group represented by R ^5a ′ (OH) _n .

The specific polymer compound in the present invention can be obtained by substituting part or all of the phenolic hydroxyl group of R ⁰¹ in the general formula (I) with the specific substituent described above. Here, the phenolic hydroxyl group (hereinafter, appropriately referred to as “hydroxyl group” in the description of the specific polymer compound) means a hydroxyl group directly bonded to a benzene skeleton present in the molecule of the polymer compound.
In the specific polymer compound, the structural unit represented by the general formula (I) is preferably contained in an amount of 10 to 60 mol%, more preferably 20 to 55 mol%, and more preferably 30 to 50 mol%. More preferably.
The ratio of replacing the phenolic hydroxyl group in the structural unit represented by the general formula (I) with a specific functional group is appropriately determined depending on the kind of the polymer compound, and preferably about 1 to 80 mol%. The amount is preferably about 1 to 60 mol%, more preferably about 1 to 40 mol%.

  The specific polymer compound in the present invention can contain other structural units other than the structural unit represented by the general formula (I) as long as the effects of the present invention are not impaired. Other structural units that can be used in combination include, for example, acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, maleic acid Examples include structural units derived from known monomers such as imides.

  Examples of acrylic esters include methyl acrylate, ethyl acrylate, (n- or i-), propyl acrylate, (n-, i-, sec- or t-) butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, Dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 5-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, methoxybenzyl Acrylate, chlorobenzyl acrylate, 2- (p-hydroxyphenyl) ethyl acrylate, furfuryl Acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, chlorophenyl acrylate, sulfamoylphenyl acrylate and the like.

  Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate (n- or i-), propyl methacrylate, (n-, i-, sec- or t-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate, dodecyl. Methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, methoxybenzyl methacrylate, chlorobenzyl Methacrylate, 2- (p-hydroxyphenyl) ethyl methacrylate DOO, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate and the like.

  Examples of acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-tolylacrylamide, N- (p-hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl) acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-N-phenyl Examples include acrylamide and N-hydroxyethyl-N-methylacrylamide.

  Examples of methacrylamides include methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-butylmethacrylamide, N-benzylmethacrylamide, N-hydroxyethylmethacrylamide, N- Phenylmethacrylamide, N-tolylmethacrylamide, N- (p-hydroxyphenyl) methacrylamide, N- (sulfamoylphenyl) methacrylamide, N- (phenylsulfonyl) methacrylamide, N- (tolylsulfonyl) methacrylamide, N, N-dimethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide and the like can be mentioned.

Examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate, and the like.
Examples of styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, propyl styrene, cyclohexyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, methoxy styrene, dimethoxy styrene, Examples include chlorostyrene, dichlorostyrene, bromostyrene, iodostyrene, fluorostyrene, carboxystyrene, and the like.

  Among these monomers, acrylic acid esters having 20 or less carbon atoms, methacrylic acid esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, and acrylonitrile are preferable.

The specific polymer compound in the present invention is preferably a polymer compound represented by the following general formula (II).

In general formula (II), R ⁰¹ represents an aromatic group having a hydroxyl group as a substituent, and R ² represents a hydrocarbon group. m = 10-60 mol%, n = 5-40 mol%, o = 1-20 mol%, p = 5-50 mol%.

In the structural unit (a), R ⁰¹ has the same meaning as R ⁰¹ in the general formula (I), and the preferred range is also the same.
In general formula (II), m which is a copolymerization ratio of the structural unit (a) is 10 to 60 mol%, more preferably 20 to 55 mol%, and more preferably 30 to 50 mol%. Further preferred.

In the polymer compound represented by the general formula (II), the structural units (a), may include only structural units having the same R ⁰¹ (a), structural units having different R ⁰¹ (a ) May be included.

In the structural unit (b), R ² represents a hydrocarbon group, and a linear, branched, or cyclic alkyl group is preferable.
Examples of R ² include a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms (preferably 3 to 10 carbon atoms), specifically, a methyl group, an ethyl group, a propyl group, or a butyl group. , Pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl Group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group, and 2-norbornyl group. Among these, an alkyl group having 3 to 10 carbon atoms is more preferable.

In general formula (II), n which is a copolymerization ratio of the structural unit (b) is 5 to 40 mol%, more preferably 10 to 35 mol%, and more preferably 15 to 30 mol%. Further preferred.
In the polymer compound represented by the general formula (II), the structural unit (b) may contain only the structural unit (b) having the same R ² , or the structural unit (b having a different R ² ) May be included.

In general formula (II), o which is a copolymerization ratio of the structural unit (c) is 1 to 20 mol%, more preferably 2 to 15 mol%, and more preferably 3 to 10 mol%. Further preferred.
Moreover, p which is a copolymerization ratio of a structural unit (d) is 5-50 mol%, It is more preferable that it is 10-45 mol%, It is further more preferable that it is 15-40 mol%.

  The polymer compound represented by the general formula (II) may contain a structural unit other than the structural units (a), (b), (c), and (d).

  Among the polymer compounds represented by the general formula (II), the specific polymer compound in the present invention is more preferably a polymer compound represented by the following general formula (III).

In the general formula (III), the structural units (a), (b), (c) and (d) are synonymous with the structural units (a), (b), (c) and (d) in the general formula (I), The preferable range is also the same.
In the structural unit (e), R ⁶ represents — (CH ₂ ) _x —COOH, —C≡CH, or a group shown below. X represents an integer of 1 or more, preferably an integer of 1 to 12. q is 0 to 20 mol%.

In the above formula, R ⁷ represents —COOH, — (CH ₂ ) _x COOH, —O— (CH ₂ ) _x COOH. X represents an integer of 1 or more, preferably an integer of 1 to 12.

  In general formula (III), q which is a copolymerization ratio of the structural unit (e) is 0 to 20 mol%, more preferably 3 to 17 mol%, and more preferably 5 to 15 mol%. Further preferred.

In the polymer compound represented by the general formula (III), the structural unit (e) may contain only the structural unit (e) having the same R ^6, and the structural unit (e) having a different R ⁶ May be included.

  Specific examples of the specific polymer compound [specific polymer compounds (a) to (h)] suitably used in the present invention are shown below, but are not limited thereto.

<Specific polymer compound (a)>
m / n / o / p / q = 37/36/2/25/0; weight average molecular weight: 16000
R ⁰¹ = 4-hydroxyphenyl group R ² = n-butyl group The phenolic hydroxyl group possessed by R ⁰¹ is substituted with the following specific substituent at a ratio of 10 mol% with respect to the total number of moles of the hydroxyl group.

<Specific polymer compound (b)>
m / n / o / p / q = 49/12/17/22/0; weight average molecular weight: 14000)
R ⁰¹ = 3-hydroxyphenyl group R ² = n-butyl group The phenolic hydroxyl group possessed by R ⁰¹ is substituted with the following specific substituent at a ratio of 7 mol% with respect to the total number of moles of the hydroxyl group.

<Specific polymer compound (c)>
m / n / o / p / q = 41/30/2/20/9; weight average molecular weight: 18000
R ⁰¹ = 2-hydroxyphenyl group R ² = n-butyl group R ³ = glyoxyl group R ⁰¹ has a phenolic hydroxyl group with the following specific substituents at a ratio of 15 mol% with respect to the total number of moles of the hydroxyl group. Replacement.

<Specific polymer compound (d)>
m / n / o / p / q = 43/21/2/24/10; weight average molecular weight: 16000
R ⁰¹ = 3-hydroxyphenyl group R ² = n-butyl group R ³ = propargyl group The phenolic hydroxyl group possessed by R ⁰¹ is the following specific substituent at a ratio of 1 mol% with respect to the total number of moles of the hydroxyl group. Replacement.

<Specific polymer compound (e)>
m / n / o / p / q = 42/38/2/18/0; weight average molecular weight: 18000
R ⁰¹ = 2-hydroxyphenyl group R ² = n-butyl group The phenolic hydroxyl group possessed by R ⁰¹ is substituted with the following specific substituent at a ratio of 7.5 mol% with respect to the total number of moles of the hydroxyl group.

<Specific polymer compound (f)>
m / n / o / p / q = 38/25/12/26/0; weight average molecular weight: 16000
R ⁰¹ = 4-hydroxyphenyl group R ² = n-butyl group The phenolic hydroxyl group possessed by R ⁰¹ is substituted with the following specific substituent at a ratio of 0.5 mol% with respect to the total number of moles of the hydroxyl group.

<Specific polymer compound (g)>
m / n / o / p / q = 10/16/12/44/18; weight average molecular weight: 18000
R ⁰¹ = 2-hydroxyphenyl group R ² = n-isobarrel group R ³ = 4-formylphenoxyl group R ⁰¹ has a phenolic hydroxyl group at a ratio of 55 mol% based on the total number of moles of the hydroxyl group. Substitute with specific substituent.

<Specific polymer compound (h)>
m / n / o / p / q = 44/14/2/40/0; weight average molecular weight: 16000
R ⁰¹ = 3,5-dibromo-4-hydroxyphenyl group R ² = n-butyl group The phenolic hydroxyl group possessed by R ⁰¹ is the following specific substituent at a ratio of 3 mol% with respect to the total number of moles of the hydroxyl group. Replace with.

(Synthesis of specific polymer compound in the present invention)
As described above, the specific polymer compound in the present invention can be obtained by substituting a part or all of the phenolic hydroxyl group of R ⁰¹ in the general formula (I) with the specific substituent described above. A polymer compound for substituting a part or all of the phenolic hydroxyl group with a specific substituent is, for example, vinyl acetate by the method described in “Polymer Chemistry”, Vol. 23, pages 348-353 (1966). And a copolymer with other copolymerization components used as needed, and then hydrolyzing the vinyl acetate part under alkaline conditions to form a copolymer of vinyl acetate and vinyl alcohol, or After obtaining a copolymer of vinyl alcohol and other copolymerization components used as needed by the method described in Kaihei 11-24272, any aldehyde such as hydroxybenzaldehyde and n-butyraldehyde Can be synthesized by the method of acetalization.

The structure of the specific polymer compound in the present invention is not particularly limited, and may be a linear polymer or a polymer having a branched structure. Moreover, when the specific polymer compound is a copolymer of each structural unit, it may have a graft structure or a block structure.
The weight average molecular weight of the specific polymer compound is preferably from 2,000 to 1,000,000, more preferably from 5,000 to 500,000, from the viewpoint of positive image-forming properties and chemical resistance. Preferably, it is the range of 10,000-300,000.

  In the case of a single-layer recording layer, the content of the specific polymer compound is preferably 50 to 99% by mass in the total solid content of the recording layer from the viewpoint of improving the comparative strength and chemical resistance of the recording layer. 60 to 97% by mass is more preferable, and 65 to 95% by mass is particularly preferable. A specific high molecular compound may be used individually by 1 type, and may use 2 or more types together.

In the single-layer recording layer, an alkali-soluble resin other than the specific polymer compound may be used in combination. Examples of the alkali-soluble resin that can be used in combination include general alkali-soluble resins that are used in a multi-layer recording layer (upper layer) described later, and among these, novolak resins are preferable.
The mixing ratio of a general alkali-soluble resin is preferably 40% by mass or less, more preferably 35% by mass or less, and particularly preferably 30% by mass or less of the total alkali-soluble resin including the specific polymer compound.

[Infrared absorber]
The single-layer recording layer in the present invention contains an infrared absorber.
The infrared absorber that can be used in the recording layer in the present invention can be used without any limitation in the absorption wavelength range as long as it is a substance that absorbs light energy irradiation rays used for recording and generates heat, but is easily available. From the viewpoint of compatibility with a high-power laser, an infrared-absorbing dye or pigment having an absorption maximum at a wavelength of 760 nm to 1200 nm is preferable.

  As the dye, commercially available dyes and 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.

  Preferred dyes include, for example, cyanine dyes described in 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-58-224793, JP-A-59- 48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc., naphthoquinone dyes, JP-A-58-112792, etc. And cyanine dyes described in British Patent 434,875.

  Also, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, pyranlium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 The pentamethine thiopyrylium salts described above and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. .

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

  Particularly preferred among these dyes are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes. Further, the dyes represented by the following general formulas (a) to (e) are preferable because they are excellent in photothermal conversion efficiency. Particularly, the cyanine dyes represented by the following general formula (a) are used in the recording layer in the 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. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se.

In the above formula, X _a ^- is, Z _a to be 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, a substituted or unsubstituted amino group and a halogen atom To express. R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the recording 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. Z _a ^- represents a counter anion. However, when the cyanine dye represented by formula (a) has an anionic substituent in its structure and does not necessitate neutralization of the charge, Z _a ^- is not necessary. Preferred Z _a ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, in view of storage stability of the recording layer coating solution. Hexafluorophosphate ions and aryl sulfonate ions.

  Specific examples of the cyanine dye represented by formula (a) that can be suitably used in the present invention include those exemplified below, and paragraph numbers [0017] to [0019] of JP-A-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 are bonded to each other to form a ring structure. Also 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 the 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 taken together, may form a ring, further, when R ³³ or R ³⁴ there are a plurality, R ³³ or between R ³⁴ each other 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, a carbonyl group, a thio group, or a sulfonyl group. , A sulfinyl group, an oxy group, an amino group, and an onium salt structure, and may further have a substituent depending on the 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 the pigment include a commercially available pigment or color index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), and “ The pigments described in “Printing Ink Technology”, published by CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment, blue pigment, green pigment, fluorescent pigment, metal powder pigment, and polymer-bonded dye. 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 A quinophthalone pigment, a dyed lake pigment, an azine pigment, a nitroso pigment, a nitro pigment, a natural pigment, a fluorescent pigment, an inorganic pigment, or carbon black can be used.

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

  The particle diameter 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, from the viewpoint of the dispersion stability in the coating liquid and the uniformity of the recording layer. It is particularly preferable that the thickness is in the range of 0.1 μm to 1 μm.

  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).

The infrared absorber may be added to the same layer as the recording layer, or another layer may be provided and added thereto. In the case of forming another layer, it is desirable to add it to a layer adjacent to the recording layer.
Furthermore, when the infrared absorber is a compound having dissolution inhibiting ability, by adding it to the same layer as the specific polymer compound, the infrared absorber can be used not only as a photothermal conversion function but also as a development inhibitor. It is preferable because it functions.
The addition amount of the infrared absorber is preferably 0.01 to 50% by mass in the total solid content of the single recording layer from the viewpoint of sensitivity and recording layer durability (film properties). It is more preferable to add 1 to 10% by mass. In the case of a dye, it is particularly preferably 0.5 to 10% by mass, and in the case of a pigment, it is particularly preferably 0.1 to 10% by mass.

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

<Development inhibitor>
The recording layer in the present invention preferably contains a development inhibitor for the purpose of enhancing its inhibition (dissolution inhibiting ability). For example, in combination with substances that substantially reduce the solubility of alkali-soluble resins, such as onium salts, o-quinonediazide compounds, aromatic sulfone compounds, and aromatic sulfonic acid ester compounds, which are thermally decomposable and do not decompose. This is preferable from the viewpoint of improving the dissolution inhibition of the image portion in the developer.

  Examples of the onium salt used in the present invention include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts, and the like. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Balet al, Polymer, 21, 423 (1980), diazonium salts described in JP-A-5-158230, U.S. Pat. Nos. 4,069,055, 4,069,056, and JP-A-3-140140. Ammonium salts described in the specification, D.I. 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,

  J. et al. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent No. 104,143, US Pat. Nos. 5,041,358, 4,491,628, JP-A-2-150848 and JP-A-2-296514. Iodonium salts, J.M. 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. et al. 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 Patents 370,693, 233,567, 297,443, 297,442, U.S. Pat. Nos. 4,933,377, 3,902,114 No. 4,491,628, No. 4,760,013, No. 4,734,444, No. 2,833,827, German Patent No. 2,904,626, No. 3,604 The sulfonium salt described in No. 580 and No. 3,604,581,

J. et al. 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).
Of these onium salts, a diazonium salt is particularly preferable. Particularly suitable diazonium salts include those described in JP-A-5-158230.

  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 assists the solubility of the upper layer by the effects of both losing the inhibition as a development inhibitor due to thermal decomposition and changing o-quinonediazide itself into an alkali-soluble substance.
Examples of such o-quinonediazide compounds include J. Org. The compounds described in pages 339 to 352 of “Light-sensitive systems” by John Coley (John Wiley & Sons. Inc.) can be used. The sulfonic acid esters or sulfonic acid amides are preferred. Further, benzoquinone (1,2) -diazide sulfonic 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-5 described in US Pat. Nos. 3,046,120 and 3,188,210. Esters of 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, 49-17474, U.S. Pat. Nos. 2,797,213, 3,454,400, 3,544,323, 3,573,917, 3,674,495, 3,785,825, British Patents 1,227,602, 1,251,345, 1,267, No. 005, No. 1,329,888, No. 1,330,932, German Patent No. 854,890, and the like.

The addition amount of the o-quinonediazide compound is preferably in the range of 0.1 to 8 mass%, more preferably 0.2 to 5 mass%, based on the total solid content of the single-layer recording layer. These compounds can be used alone, but may be used as a mixture of several kinds.
Moreover, you may include the alkali-soluble resin by which at least one part of Unexamined-Japanese-Patent No. 11-288089 was esterified.

Further, for the purpose of enhancing the inhibition of the scratch on the surface as well as the inhibition of the recording layer surface, the perfluoroalkyl having 3 to 20 carbon atoms in the molecule as described in JP-A-2000-187318. It is preferable to use a polymer having a (meth) acrylate monomer having 2 or 3 groups as a polymerization component.
The addition amount is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass, based on the total solid content of the single-layer recording layer.

<Development accelerator>
For the purpose of improving sensitivity, acid anhydrides, phenols, and organic acids may be added to the single-layer recording layer in the present invention.
As the acid anhydrides, cyclic acid anhydrides are preferable. Specific examples of the cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride described in US Pat. No. 4,115,128. Acid, 3,6-endooxy-Δ4-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. Examples of the non-cyclic acid anhydride include acetic anhydride.

  Examples of phenols include bisphenol A, 2,2′-bishydroxysulfone, p-nitrophenol, p-ethoxyphenol, 2,4,4′-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4- Examples include hydroxybenzophenone, 4,4 ′, 4 ″ -trihydroxytriphenylmethane, 4,4 ′, 3 ″, 4 ″ -tetrahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane. .

Examples of organic acids include sulfonic acids, sulfinic acids, alkylsulfuric acids, phosphonic acids, phosphate esters, and carboxylic acids described in JP-A-60-88942 and JP-A-2-96755. Specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid , P-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene-1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid and the like.
The proportion of the acid anhydride, phenols and organic acids in the total solid content of the single-layer recording layer is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, and particularly preferably 0. .1 to 10% by mass.

<Surfactant>
The single-layer recording layer in the present invention is described in JP-A Nos. 62-251740 and 3-208514 in order to improve the coating properties and to expand the stability of processing with respect to development conditions. Nonionic surfactants as described above, amphoteric surfactants as described in JP-A-59-121044, JP-A-4-13149, and siloxane-based compounds as described in EP950517 Compounds, fluorine-containing monomer copolymers as described in JP-A-62-170950, JP-A-11-288093, and Japanese Patent Application No. 2001-247351 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 amphoteric activators 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.).

As the siloxane compound, a block copolymer of dimethylsiloxane and polyalkylene oxide is preferable. 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 amphoteric surfactant in the total solid content of the single-layer recording layer is preferably 0.01 to 15% by mass, more preferably 0.1 to 5.0% by mass, and still more preferably. Is 0.5-2.0 mass%.

<Bake-out agent / colorant>
A print-out agent for obtaining a visible image immediately after heating by exposure or a dye or pigment as an image colorant can be added to the single-layer recording layer in the present invention.
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 aforementioned 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) Co., Ltd.), Victoria Pure Blue, Crystal Violet Lactone, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI52015), etc. it can. The dyes described in JP-A-62-293247 are particularly preferred.
These dyes can be added in a proportion of 0.01 to 10% by mass, preferably 0.1 to 3% by mass, based on the total solid content of the single-layer recording layer.

<Plasticizer>
A plasticizer may be added to the single-layer recording layer in the present invention in order to impart flexibility and the like 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.
These plasticizers can be added in a proportion of 0.5 to 10% by mass, preferably 1.0 to 5% by mass, based on the total solid content of the single-layer recording layer.

<WAX agent>
For the purpose of imparting scratch resistance, a compound that lowers the static friction coefficient of the surface can be added to the single-layer recording layer in the present invention. Specifically, US Pat. No. 6,117,913 or Japanese Patent Application Nos. 2001-261627, 2002-032904, and 2002-165854 previously proposed by the applicant of the present application. And compounds having an ester of a long-chain alkyl carboxylic acid as described in the above.
As the amount added, the proportion of the total solid content of the single-layer recording layer is preferably 0.1 to 10% by mass, and more preferably 0.5 to 5% by mass.

[Multilayer recording layer]
Next, the case where the positive recording layer of the planographic printing plate precursor of the present invention has a multilayer structure composed of a plurality of layers having different constituent components will be described.
In the multi-layer recording layer of the present invention, the specific polymer compound, which is a characteristic component of the present invention, may be contained in any layer, but is preferably contained in the lower layer. That is, the multilayer recording layer in the present invention contains a lower layer containing a specific polymer compound, an alkali-soluble resin, and a compound that forms an interaction with the alkali-soluble resin and decreases the solubility in an alkali developer. A positive recording layer comprising an upper layer is preferred. At least one of the lower layer and the upper layer of the recording layer contains an infrared absorber.
Hereinafter, such a multilayer recording layer will be described in detail.

(Underlayer)
The lower layer in the present invention preferably contains the specific polymer compound described above.
The content of the specific polymer compound in the lower layer of such a multilayer recording layer is 50 to 99% by mass in the total solid content of the lower recording layer from the viewpoint of improving the film properties and chemical resistance of the recording layer. It is preferably 65 to 97% by mass, and particularly preferably 75 to 95% by mass.

In the lower layer of the multilayer recording layer, only such a specific polymer compound may be used as a binder resin. However, in addition to the specific polymer compound, the effect of the present invention is impaired from the viewpoint of improving film properties. Other resins can be used in combination as long as they are not present.
Since the lower layer itself needs to express alkali solubility, particularly in the non-image area, it is necessary to select a resin that does not impair this property. From this viewpoint, examples of the resin that can be used in combination include alkali-soluble resins other than the specific polymer compound. As for the alkali-soluble resin that can be used in combination with the specific polymer compound, a general alkali-soluble resin described later can be used as an upper layer component. Among these, for example, polyamide resins, resins containing epoxy groups, polyvinyl acetal resins, acrylic resins, methacrylic resins, polystyrene resins, novolac phenolic resins, polyurethane resins and the like can be preferably exemplified.
As a ratio which mixes general alkali-soluble resin, 40 mass% or less of all the alkali-soluble resins contained in a lower layer is preferable, 35 mass% or less is more preferable, It is especially preferable that it is 30 mass% or less.

  Moreover, as a component contained in the lower layer in this invention, another additive can be further used as needed. Examples of other additives include development accelerators, surfactants, printout / coloring agents, plasticizers, and WAX agents. The details of these components are the same as those described as components of the upper layer described later.

(Upper layer)
The upper layer in the present invention preferably contains an alkali-soluble resin other than the specific polymer compound and a compound that forms an interaction with the alkali-soluble resin and decreases the solubility in an alkali developer.

[Alkali-soluble resin]
The alkali-soluble resin that can be used in the upper layer is not particularly limited as long as it has a property of dissolving when contacted with an alkaline developer, but it contains an acidic group in the main chain and / or side chain in the polymer. It is preferably a polymer, a copolymer thereof, or a mixture thereof. Moreover, the above-mentioned specific polymer compound can also be added to the upper layer.
Examples of the alkali-soluble resin having such an acidic group include (1) phenolic hydroxyl group, (2) sulfonamide group, (3) active imide group, (4) carboxylic acid group, and (5) phosphoric acid group. Examples thereof include polymer compounds having any functional group in the molecule, and among them, a polymer compound having (1) a phenolic hydroxyl group, (2) a sulfonamide group, and (3) an active imide group is particularly preferable. Examples of such a polymer compound include the following, but the present invention is not limited thereto.

  (1) Examples of the polymer compound having a phenolic hydroxyl group include phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m-, p Any of-or m- / p-mixing) may be used. Examples thereof include novolak resins such as mixed formaldehyde resins and pyrogallol acetone resins. In addition to this, a polymer compound having a phenolic hydroxyl group in the side chain is preferably used as the polymer compound having a phenolic hydroxyl group. As a polymer compound having a phenolic hydroxyl group in the side chain, a polymerizable monomer comprising a low molecular compound having at least one phenolic hydroxyl group and at least one polymerizable unsaturated bond is homopolymerized, or other polymerization is performed on the monomer. And a high molecular compound obtained by copolymerizing a functional monomer.

  Examples of the polymerizable monomer having a phenolic hydroxyl group include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene having a phenolic hydroxyl group. Specifically, N- (2-hydroxyphenyl) acrylamide, N- (3-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) acrylamide, N- (2-hydroxyphenyl) methacrylamide, N- (3- Hydroxyphenyl) methacrylamide, N- (4-hydroxyphenyl) methacrylamide, o-hydroxyphenyl acrylate, m-hydroxyphenyl acrylate, p-hydroxyphenyl acrylate, o-hydroxyphenyl methacrylate, m-hydroxyphenyl methacrylate, p-hydroxy Phenyl methacrylate, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (2-hydroxyphenyl) ethyl acrylate, 2- (3-hydroxyphenyl) Preferable are til acrylate, 2- (4-hydroxyphenyl) ethyl acrylate, 2- (2-hydroxyphenyl) ethyl methacrylate, 2- (3-hydroxyphenyl) ethyl methacrylate, 2- (4-hydroxyphenyl) ethyl methacrylate, etc. Can be used. Such resins having a phenolic hydroxyl group may be used in combination of two or more. Furthermore, as described in US Pat. No. 4,123,279, phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, These copolymers may be used in combination.

(2) The alkali-soluble resin having a sulfonamide group includes a polymer compound obtained by homopolymerizing a polymerizable monomer having a sulfonamide group or copolymerizing the monomer with another polymerizable monomer. The polymerizable monomer having a sulfonamide group includes one or more sulfonamide groups —NH—SO ₂ — in which at least one hydrogen atom is bonded on a nitrogen atom and one or more polymerizable unsaturated bonds in one molecule. And a polymerizable monomer comprising a low molecular weight compound. Among these, 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 is preferable.

(3) The alkali-soluble resin having an active imide group is preferably one having an active imide group in the molecule, and the polymer compound has one unsaturated bond polymerizable with the active imide group in each molecule. Examples thereof include a polymer compound obtained by homopolymerizing a polymerizable monomer comprising the above-described low molecular weight compound, or copolymerizing the monomer with another polymerizable monomer.
As such a compound, 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 an alkali-soluble resin having a phosphoric acid group, for example, a minimum structural unit derived from a compound having at least one phosphoric acid group and a polymerizable unsaturated group in the molecule is used as a main constituent component. A polymer can be mentioned.

  The alkali-soluble resin used in the upper layer is a polymer compound obtained by polymerizing two or more of the polymerizable monomer having a phenolic hydroxyl group, the polymerizable monomer having a sulfonamide group, and the polymerizable monomer having an active imide group. It is preferable that Although there is no restriction | limiting in the copolymerization ratio of the said polymerizable monomer, and the combination of a polymerizable monomer, Especially the polymerizable monomer which has a sulfonamide group in the polymerizable monomer which has a phenolic hydroxyl group, and / or the polymerizable property which has an active imide group When monomers are copolymerized, the compounding polymerization ratio of these components is preferably in the range of 50:50 to 5:95, and particularly preferably in the range of 40:60 to 10:90.

Furthermore, as the alkali-soluble resin used in the upper layer, one or two or more kinds selected from the polymerizable monomer having a phenolic hydroxyl group, the polymerizable monomer having a sulfonamide group, or the polymerizable monomer having an active imide group are used. In addition to the polymerizable monomer, a polymer compound obtained by copolymerizing another polymerizable monomer is preferable. As a copolymerization ratio in this case, it is preferable that the monomer which provides alkali solubility is included 10 mol% or more from a viewpoint of developability, and what contains 20 mol% or more is more preferable.
Examples of other polymerizable monomers that can be used here include the compounds listed in the following (m1) to (m12), but the present invention is 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.
(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.

When the alkali-soluble resin used in the upper layer is a homopolymer or copolymer of a polymerizable monomer having a phenolic hydroxyl group, a polymerizable monomer having a sulfonamide group, or a polymerizable monomer having an active imide group, Those having a molecular weight of 2,000 or more and a number average molecular weight of 500 or more are preferred. More preferably, the weight average molecular weight is 5,000 to 300,000, the number average molecular weight is 800 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10. .
In particular, when the alkali-soluble resin used in the upper layer in the present invention is a phenol formaldehyde resin or a cresol aldehyde resin, the weight average molecular weight is 500 to 20,000, and the number average molecular weight is 200 to 10, 000 is preferred.

As the alkali-soluble resin used in the upper layer, a resin having a phenolic hydroxyl group is desirable because it causes strong hydrogen bonding in the unexposed area and some hydrogen bonds are easily released in the exposed area. Among the resins having a functional hydroxyl group, a novolak resin is particularly preferable.
In the present invention, two or more kinds of alkali-soluble resins having different dissolution rates in an alkaline aqueous solution may be mixed and used, and the mixing ratio in that case is arbitrary. The alkali-soluble resin suitable for mixing with the resin having a phenolic hydroxyl group is preferably an acrylic resin because of its low compatibility with a resin having a phenolic hydroxyl group, and more preferably a sulfoamide group. It is an acrylic resin.

  The content of the alkali-soluble resin relative to the total solid content of the upper layer is preferably used in an addition amount of 50 to 98% by mass from the viewpoints of durability and sensitivity of the recording layer.

[Infrared absorber]
When the recording layer in the present invention is a multilayer recording layer, an infrared absorber is added to at least one of the lower layer and the upper layer of the recording layer. As the infrared absorber, the same infrared absorber as that used in the single-layer recording layer can be used.
These infrared absorbers may be added to the lower layer, the upper layer, or both the upper and lower layers, but are preferably added to the upper layer of the recording layer or the vicinity thereof from the viewpoint of sensitivity. In particular, it is preferable to add an infrared absorber having dissolution inhibiting ability to the same layer as the alkali-soluble resin in the upper layer, so that the unexposed area can have alkali solubility resistance at the same time as high sensitivity. .
On the other hand, when added to the lower layer, it is possible to realize further higher sensitivity. When the infrared absorber is added to both the upper layer and the lower layer, the same compound may be used, or different compounds may be used.
These infrared absorbers may be added to the same layer as the upper and lower recording layers, or may be added to another layer provided. In the case of forming another layer, it is desirable to add it to a layer adjacent to the recording layer.

  As the addition amount of the infrared absorber, from the viewpoint of sensitivity and durability (film properties) of the recording layer when added to the upper layer, it is 0.01 to 30% by mass, preferably 0.1%, based on the total solid content of the upper layer. It can be added at a ratio of ˜20% by mass, particularly preferably 1.0 to 10% by mass.

  On the other hand, when adding to a lower layer, it is 0-20 mass% with respect to a lower layer total solid, Preferably it is 0-10 mass%, Most preferably, it can add in the ratio of 0-5 mass%. When an infrared absorber is added to the lower layer, the solubility of the lower layer decreases if an infrared absorber having dissolution inhibiting ability is used. On the other hand, the infrared absorber generates heat during infrared laser exposure, and the solubility of the lower layer is improved by heat. Therefore, the compound to be added and the addition amount should be selected in consideration of these balances. In the region of 0.2 to 0.3 μm in the vicinity of the support, it is difficult to obtain the effect of improving the solubility due to heat, for example, the heat generated during exposure diffuses to the support. In some cases, the decrease in sensitivity may cause a decrease in sensitivity. Therefore, even within the range of the addition amount shown above, such an addition amount that the dissolution rate in the lower layer developer (25 ° C. to 30 ° C.) is lower than 30 nm / sec is not preferable.

(Development inhibitor)
The upper layer in the present invention preferably contains a development inhibitor for the purpose of enhancing its inhibition (dissolution inhibiting ability). In particular, when an infrared absorber that does not have dissolution inhibiting ability is used, this development inhibitor can be an important component for maintaining the alkali resistance of the image area.
As the development inhibitor used for the multi-layer recording layer, the same development inhibitors as those described for the component of the single-layer recording layer can be used. Further, among the image colorants described later, there are compounds that function as a development inhibitor, and they are also preferably mentioned.

For example, in combination with substances that are thermally decomposable, such as onium salts, o-quinonediazide compounds, aromatic sulfone compounds, aromatic sulfonic acid ester compounds, and that substantially reduce the solubility of alkali-soluble resins when not decomposed It is preferable to improve the inhibition of the image portion to the developer.
As the onium salt, those similar to the onium salts mentioned as the development inhibitor for the single-layer recording layer can be used.
As the o-quinonediazides, those similar to the o-quinonediazides mentioned as the development inhibitor for the single-layer recording layer can be used.
The addition amount of the o-quinonediazide compound is preferably in the range of 1 to 50% by mass, more preferably 5 to 30% by mass, and particularly preferably 10 to 30% by mass with respect to the total solid content of the upper layer.

Further, for the purpose of enhancing the inhibition of the scratch on the surface as well as the inhibition of the recording layer surface, the perfluoroalkyl having 3 to 20 carbon atoms in the molecule as described in JP-A-2000-187318. It is preferable to use a polymer having a (meth) acrylate monomer having 2 or 3 groups as a polymerization component.
As addition amount, 0.1-10 mass% is preferable with respect to upper layer total solid, More preferably, it is 0.5-5 mass%.

[Other additives]
In forming the lower layer and the upper layer of the polymerization type recording layer, in addition to the above essential components, various additives can be further added as necessary as long as the effects of the present invention are not impaired. The additives listed below may be added only to the lower layer, may be added only to the upper layer, or may be added to both layers.

<Development accelerator>
A development accelerator may be added to the upper layer and / or the lower layer, which is the recording layer in the present invention, for the purpose of improving sensitivity. As such a development accelerator, acid anhydrides, phenols, and organic acids mentioned as the development accelerator for the single-layer recording layer can be used.
The proportion of the acid anhydride, phenols and organic acids in the total solid content of the lower layer or upper layer is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, particularly preferably 0. 1 to 10% by mass.

<Surfactant>
A surfactant can be added to the upper layer and / or the lower layer, which is the recording layer in the present invention, in order to improve the coating property and to expand the stability of the processing with respect to the development conditions. As such a surfactant, the nonionic surfactants and amphoteric surfactants exemplified as the surfactant for the single-layer recording layer can be used.
The ratio of the nonionic surfactant and the amphoteric surfactant to the total solid content of the lower layer or upper layer is preferably 0.01 to 15% by mass, more preferably 0.1 to 5.0% by mass, and still more preferably 0. .5 to 2.0% by mass.

<Bake-out agent / colorant>
In the upper layer and / or the lower layer as the recording layer in the present invention, 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.
As such print-out agent or image colorant, the same print-out agent or image colorant as those mentioned for the single-layer recording layer can be used.
These dyes can be added in a proportion of 0.01 to 10% by mass, preferably 0.1 to 3% by mass, based on the total solid content of the lower layer or the upper layer.

<Plasticizer>
A plasticizer may be added to the upper layer and / or the lower layer, which are recording layers in the present invention, in order to impart flexibility and the like of the coating film. As such a plasticizer, the same plasticizers as those mentioned for the single-layer recording layer can be used.
These plasticizers can be added at a ratio of 0.5 to 10% by mass, preferably 1.0 to 5% by mass, based on the total solid content of the lower layer or the upper layer.

<WAX agent>
In the upper layer of the present invention, a compound that lowers the static friction coefficient of the surface can be added for the purpose of imparting resistance to scratches. As such a compound, the same compounds as the WAX agent exemplified in the single-layer recording layer can be used. The addition amount is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass in the upper layer.

[Formation of recording layer]
The recording layer in the present invention (single layer type recording layer or lower layer or upper layer of the multi-layer type recording layer) is usually prepared by dissolving the above-mentioned components in a solvent to form a recording layer coating solution and coating it on a suitable support. Can be formed.
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.

In particular, in the multilayer recording layer, it is preferable that the lower layer and the upper layer are formed by separating the two layers in principle.
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.
Hereinafter, although these methods are explained in full detail, the method of isolate | separating and apply | coating two layers is not limited to these.

  As a method of utilizing the difference in solvent solubility between the component contained in the lower layer and the component contained in the upper layer, a solvent system in which any of the components contained in the lower layer is insoluble is used when the upper layer coating solution is applied. Is. Thereby, even if it carries out 2 layer application | coating, it becomes possible to isolate | separate each layer clearly and to make a coating film. For example, as the lower layer component, a component insoluble in a solvent such as methyl ethyl ketone or 1-methoxy-2-propanol that dissolves the alkali-soluble resin that is the upper layer component is selected, and the lower layer is applied using a solvent system that dissolves the lower layer component. -It is possible to form two layers by drying and then dissolving the upper layer component mainly composed of alkali-soluble resin with methyl ethyl ketone, 1-methoxy-2-propanol, etc., and applying and drying.

  Next, after applying the second layer (upper layer), as a method of drying the solvent very quickly, a method of blowing high-pressure air from a slit nozzle installed substantially perpendicular to the running direction of the web, heating with steam, etc. The method of giving thermal energy as conduction heat from the lower surface of the web from the roll (heating roll) supplied inside the medium, or a combination of these methods can be mentioned.

  Moreover, in order to provide a new function, the upper layer and the lower layer may be partially miscible in a range where the effects of the present invention are sufficiently exhibited. Such a method can be achieved by adjusting the degree of any of the above methods using the difference in solvent solubility and the method of drying the solvent very quickly after coating the second layer.

The concentration of the above-described components (total solid content including additives) in the recording layer coating solution coated on the support 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.
In particular, when applying the upper layer in the multi-layer recording layer, it is desirable that the upper layer application method is a non-contact type in order to prevent damage to the lower layer. Further, although it is a contact type, it is possible to use bar coater coating as a method generally used for solvent-based coating, but it is desirable to perform coating by forward rotation in order to prevent damage to the lower layer.

In the single-layer recording layer, the coating amount of the recording layer component after drying is preferably in the range of 0.7 to 4.0 g / m ² from the viewpoint of sensitivity and printing durability, and more preferably 0. The range is from 8 to 3.0 g / m ² . In the present invention, a recording layer having excellent printing durability and chemical resistance can be formed even in a thin layer by the function of the specific polymer compound. Therefore, it is generally suitable for forming a single-layer recording layer. Even if the coating amount is less than the above-mentioned range, it is a great feature that a lithographic printing plate precursor suitable for practical use can be obtained, which is preferable from the viewpoint of image reproducibility (image quality).

In the multi-layer recording layer, the coating amount of the lower layer component after drying is preferably in the range of 0.5 to 4.0 g / m ² , more preferably 0.6, from the viewpoint of sensitivity and printing durability. It is in the range of ˜2.5 g / m ² .
The coating amount of the upper layer component after drying is preferably in the range of 0.05 to 1.0 g / m ² , and more preferably 0.08 to 0.08 from the viewpoint of sensitivity, development latitude, scratch resistance, and the like. The range is 0.7 g / m ² .
The coating amount after drying combining the lower layer and the upper layer is preferably in the range of 0.6 to 4.0 g / m ² , more preferably from the viewpoint of sensitivity, image reproducibility, printing durability, and the like. in the range of 0.7 to 2.5 g / m ^2.

[Support]
The support used in the present invention is not particularly limited as long as it is a dimensionally stable plate having necessary strength and durability. For example, paper, plastic (for example, polyethylene, polypropylene, polystyrene) Etc.) laminated paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate) , Polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper laminated with metal as described above, or vapor-deposited paper, or plastic film.

  Among them, in the present invention, a polyester film or an aluminum plate is preferable, and 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.

Such an aluminum plate may be subjected to surface treatment such as roughening treatment or anodizing treatment, if necessary. Hereinafter, such a surface treatment will be briefly described.
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 aluminum plate roughened as described above is subjected to an alkali etching treatment and neutralization treatment as necessary, and then subjected to an anodizing 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 planographic printing plate is easily damaged, and 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.

(Undercoat layer)
In the image recording material of the present invention, an undercoat layer can be provided between the support and the recording layer as necessary.
Various organic compounds are used as the undercoat layer component. For example, phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, phenylphosphonic acid which may have a substituent, Organic phosphonic acids such as naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, optionally substituted phenylphosphoric acid, naphthylphosphonic acid, alkylphosphoric acid and glycerophosphoric acid Organic phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, organic phosphinic acids such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and hydrochloride of triethanolamine Hydroxy groups such as Selected from hydrochloride of the amine to be, but may be used by mixing two or more.

  The undercoat layer preferably contains a compound having an onium group. The compounds having an onium group are described in detail in JP-A Nos. 2000-10292 and 2000-108538. In addition, a compound selected from the group of polymer compounds having a structural unit represented by poly (p-vinylbenzoic acid) in the molecule can also be used. Specific examples of these polymer compounds include a copolymer of p-vinylbenzoic acid and vinylbenzyltriethylammonium salt, a copolymer of p-vinylbenzoic acid and vinylbenzyltrimethylammonium chloride, and the like. .

This organic undercoat layer can be provided by the following method. That is, a method in which water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is dissolved and applied on an aluminum plate and dried, and water, methanol, ethanol, methyl ethyl ketone, etc. In this method, an aluminum plate is immersed in a solution in which the above organic compound is dissolved in the above organic solvent or a mixed solvent thereof to adsorb the above compound, and then washed with water or the like and dried to provide an organic undercoat layer. In the former method, a solution having a concentration of 0.005 to 10% by mass of the organic compound can be applied by various methods. In the latter method, the concentration of the solution is 0.01 to 20% by mass, preferably 0.05 to 5% by mass, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The solution used for this can be adjusted to a pH range of 1 to 12 with a basic substance such as ammonia, triethylamine or potassium hydroxide, or an acidic substance such as hydrochloric acid or phosphoric acid. A yellow dye can also be added to improve the tone reproducibility of the image recording material.
The coverage of the organic undercoat layer, from the viewpoint of printing durability, 2 to 200 mg / m ² are suitable, and preferably from 5 to 100 mg / m ^2.

[Back coat layer]
A back coat layer is provided on the back surface of the support of the image recording material of the present invention as 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.

[Plate making of lithographic printing plate precursor]
The image recording material produced as described above is mainly suitably used as a positive planographic printing plate precursor. Hereinafter, a plate making process (image exposure, development processing, printing process) when the image recording material of the present invention is used as a lithographic printing plate precursor will be described.

(exposure)
As the light source of the light beam used for image exposure, a light source having an emission wavelength in the near infrared to infrared region is preferable, and a solid laser or a semiconductor laser is particularly preferable.

(developing)
As the developer and replenisher for a lithographic printing plate precursor using the image recording material of the present invention, conventionally known alkaline aqueous solutions can be used.
For example, sodium silicate, potassium, trisodium 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. In addition, 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.

Further, 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 a large amount of the developer can be obtained without replacing the developer in the developer tank for a long time. It is known that PS plates 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 and potassium salts, organic carboxylic acids, antifoaming agents, and hard water softeners. It can also be added.
The lithographic printing plate precursor developed by using the developer and the replenisher is post-treated with a desensitizing solution containing rinse water containing a washing water, a surfactant or the like, gum arabic or a starch derivative. In the case of using the image recording material of the present invention as a lithographic printing plate precursor, 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 using the image recording material of the present invention, an image portion unnecessary for the lithographic printing plate obtained by image exposure, development, washing and / or rinsing and / or gumming (for example, an original image). If there is a film edge mark or the like of the film, unnecessary image portions are erased. Such erasing is preferably performed, for example, by applying an erasing solution as described in 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.

(Heat treatment (burning treatment))
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 particular, in the present invention, since the lower layer contains a specific polymer compound having a phenolic hydroxyl group and has thermal crosslinkability, the printing durability is remarkably improved by performing a general-purpose burning treatment.

Prior to the burning treatment, the surface is treated with a surface conditioning solution as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859, and JP-A-61-159655. It is preferable. 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). Thereafter, the lithographic printing plate coated with the leveling liquid may be dried as necessary.

Subsequently, the lithographic printing plate in the present invention is subjected to heat treatment. The heat treatment method is not particularly limited as long as heat can be applied to the plate surface and the effect of improving the burning printing durability, which is one of the effects of the present invention, can be expressed. The method of heating is mentioned.
In the present invention, among the above heating methods, a method of heating to a high temperature with a burning processor (for example, a burning processor sold by Fuji Photo Film Co., Ltd .: “BP-1300”) or the like is preferable. The heating temperature and the heating time in this case depend on the types of components constituting the upper layer and the image recording layer, but are preferably in the range of 150 to 300 ° C., 0.5 to 20 minutes, and in the range of 180 to 270 ° C. The range of 1 to 10 minutes is more preferable.

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 or the like is used. If so, so-called desensitizing treatment such as gumming can be omitted.
The lithographic 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)
The support body was produced by processing through the process shown below using a JIS-A-1050 aluminum plate with a thickness of 0.3 mm.

(A) Mechanical surface roughening treatment While supplying a suspension of abrasive (silica sand) having a specific gravity of 1.12. Roughening was performed. The average particle size of the abrasive was 8 μm, and the maximum particle size was 50 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 50 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 sprayed with an aqueous NaOH solution at a temperature of 70 ° C. (concentration 26 mass%, aluminum ion concentration 6.5 mass%) to perform an etching treatment, and the aluminum plate was 6 g / m. ² dissolved. Thereafter, washing with water was performed using well water.

(C) Desmut treatment A desmut treatment was performed by spraying with a 1% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in 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 nitric acid 10.5 g / liter aqueous solution (aluminum ion 5 g / liter) at a temperature of 50 ° C. The AC power supply waveform is electrochemically roughened using a carbon electrode as the counter electrode, using a trapezoidal rectangular wave alternating current with a time TP of 0.8 msec until the current value reaches a peak from zero, a DUTY ratio of 1: 1. went. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
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.
Thereafter, washing with water was performed using well water.

(E) Alkaline etching treatment An aluminum plate is etched by spraying at a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass at 32 ° C., 0.20 g / m ^{2 of the} aluminum plate is dissolved, The smut component mainly composed of aluminum hydroxide generated when electrochemical surface roughening was used was removed, and the edge portion of the generated pit was melted to smooth the edge portion. Thereafter, washing with water was performed using well water.

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

(G) Electrochemical surface roughening treatment An electrochemical surface roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 7.5 g / liter aqueous solution (containing 5 g / liter of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform was a rectangular wave, and an electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
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.
Thereafter, washing with water was performed using well water.

(H) Alkali etching treatment The aluminum plate was sprayed at a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass at 32 ° C. to dissolve the aluminum plate at 0.10 g / m ² , The smut component mainly composed of aluminum hydroxide generated during the electrochemical surface roughening treatment was removed, and the edge portion of the generated pit was dissolved to smooth the edge portion. Thereafter, washing with water was performed using well water.

(I) Desmut treatment A desmut treatment by spraying was performed with a 25% by mass aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by mass of aluminum ions), and then water washing by spraying was performed using well water.

(J) Anodizing treatment As the electrolytic solution, sulfuric acid was used. The electrolyte solutions all had a sulfuric acid concentration of 170 g / liter (containing 0.5 mass% of aluminum ions), and the temperature was 43 ° C. Thereafter, washing with water was performed using well water.
Both current densities were about 30 A / dm ² . The final oxide film amount was 2.7 g / m ² .

<Support A>
The steps (a) to (j) were sequentially performed, and the support A was produced so that the etching amount in the step (e) was 3.4 g / m ² .
<Support B>
A support B was prepared by sequentially performing the steps except that the steps (g), (h), and (i) were omitted.

<Support C>
A support C was prepared by sequentially performing the steps except that the steps (a), (g), (h), and (i) were omitted.
<Support D>
Except for omitting the process of the above step (a) and (d) (e) (f ) performs the steps in turn, supported as total amount of electricity is 450C / dm ² in step (g) Body D was prepared.
The following supports A, B, C and D were then subjected to the following hydrophilic treatment and undercoating treatment.

(K) Alkali metal silicate treatment An aluminum support obtained by anodizing treatment was immersed in a treatment layer of a 1 mass% aqueous solution of sodium silicate No. 3 at a temperature of 30 ° C. for 10 seconds to immerse the alkali metal silica. Acid salt treatment (silicate treatment) was performed. Then, the water washing by the spray using well water was performed. The amount of silicate adhering at that time was 3.6 mg / m ² .

[Undercoating]
On the aluminum support after the alkali metal silicate treatment obtained as described above, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds. The coating amount after drying was 15 mg / m ² .

(Undercoat liquid)
・ The following polymer compound (I or II) 0.3 g
・ Methanol 100g
・ Water 1g

(Formation of recording layer)
Next, the lower layer coating liquid A having the following composition was applied to the support with the undercoat obtained above with a wire bar, and then dried in a drying oven at 120 ° C. for 30 seconds to obtain a coating amount of 0.85 g. / M ² .
The uppermost layer coating liquid B having the following composition was applied to the obtained support with a lower layer with a wire bar. After coating, drying was performed at 130 ° C. for 40 seconds to obtain a positive planographic printing plate precursor of Examples 1 to 3 and Comparative Examples 1 and ² , with the total coating amount being 1.07 g / m ² .

<Coating liquid A for lower layer>
・ 2.03 g of specific polymer compounds listed in Table 1 below
・ Cyanine dye P (the following structure) 0.124 g
・ Bis-p-hydroxyphenylsulfone 0.156 g
・ Tetrahydrophthalic anhydride 0.35g
・ 0.007 g of p-toluenesulfonic acid
2-methoxy-4- (N-phenylamino)
Benzenediazonium hexafluorophosphate 0.042g
・ Ethyl violet 6-naphthalenesulfonic acid 0.066g
-Fluorosurfactant (Megafac F-780, manufactured by Dainippon Ink & Chemicals, Inc.) 0.035g
・ Γ-Butyrolactone 13.16g
・ Methyl ethyl ketone 25.39g
・ 1-methoxy-2-propanol 12.95 g

<Coating solution B for top layer>
-Phenol / m-cresol / p-cresol novolak resin (molar ratio 50:30:20, weight average molecular weight 5,000) 0.241 g
・ Cyanine dye P (the following structure) 0.019 g
・ The following structural polymer Q / MEK 30% solution (the following structure) 0.24 g
・ Methyl ethyl ketone 2.53g
・ 1-methoxy-2-propanol 5.27g

[Examples 4 to 6, Comparative Examples 3 and 4]
The coating liquid C having the following composition was applied to a support with an undercoat layer obtained by the same method as in Examples 1 to 3 with a wire bar. After coating, drying at 130 ° C. for 30 seconds was performed, and positive lithographic printing plate precursors of Examples 4 to 6 and Comparative Examples 3 and 4 were obtained with a total coating amount of 1.80 g / m ² .

<Coating liquid C>
・ 0.65 g of specific polymer compounds listed in Table 1 below
-Phenol / m-cresol / p-cresol novolak resin (molar ratio 50:30:20, weight average molecular weight 5,000) 0.25 g
・ 0.003 g of p-toluenesulfonic acid
・ Tetrahydrophthalic anhydride 0.03g
・ Cyanine dye P (structure shown below) 0.017g
・ Victoria Pure Blue (Dye with BOH counter anion as 1-naphthalenesulfonic acid anion) 0.015g
・ Γ-Butyllactone 10g
・ Methyl ethyl ketone 10g
1-methoxy-2-propanol 1g

[Examples 7 to 9, Comparative Examples 5 and 6]
The coating liquid D having the following composition was applied to a support with an undercoat layer obtained by the same method as in Examples 1 to 3 using a wire bar. After coating, drying at 130 ° C. for 30 seconds was performed, and the total coating amount was 1.40 g / m ² to obtain positive type lithographic printing plate precursors of Examples 7 to 9 and Comparative Examples 5 and 6.

<Coating liquid D>
-2.134 g of specific polymer compounds described in Table 1 below
・ Cyanine dye P (structure shown below) 0.052g
・ Ethyl violet 6-naphthalenesulfonic acid 0.078g
・ Methyl ethyl ketone 25.30g

[Evaluation of planographic printing plate precursor]
Next, performance evaluation of the positive type lithographic printing plate precursors of Examples 1 to 9 and Comparative Examples 1 to 6 was performed. In addition, the evaluation test was done about what was preserve | saved for 30 days at 25 degreeC after application | coating.

(Evaluation of development latitude)
The positive lithographic printing plate precursors of Examples 1 to 9 and Comparative Examples 1 to 6 thus obtained were drawn in a test pattern image on a Trend setter 800 manufactured by Creo under the conditions of a beam intensity of 12.0 W and a drum rotation speed of 120 rpm. (Exposure) was performed.
Next, with respect to Examples 1 to 6 and Comparative Examples 1 to 4, the carbon dioxide was diluted with water dilution (1: 9) of the developer DT-2R manufactured by Fuji Photo Film Co., Ltd. until the conductivity reached 44 mS / cm. The liquid temperature was adjusted to 35 ° C. using a PS processor LP-940HII manufactured by Fuji Photo Film Co., Ltd., which was charged with a liquid in which gas was blown and a water dilution (1: 1) solution of Finisher FG-1 manufactured by Fuji Photo Film Co., Ltd. Development was carried out with a development time of 20 seconds. Thereafter, an appropriate amount of DT-2R diluted with water (1: 9) was added to the developer, the conductivity was adjusted to 45 mS / cm, and the lithographic printing plate precursor in which the test pattern was drawn in an image shape as before was developed. . Further, the electrical conductivity was increased by 2 mS / cm, and this operation was continued until a film loss due to image development was observed remarkably.
For Examples 7 to 9 and Comparative Examples 5 and 6, Fuji Photo Film Co., Ltd. was used in which carbon dioxide gas was blown into the developer LH-DRS manufactured by Fuji Photo Film Co., Ltd. until the conductivity reached 80 mS / cm. Using a PS processor LP940HII manufactured by Fuji Photo Film Co., Ltd., which was charged with a water diluted (1: 1) solution of Finisher FP-2W manufactured by Co., Ltd., development was performed at a development time of 26 seconds while maintaining the liquid temperature at 40 ° C. Thereafter, an appropriate amount of carbon dioxide gas was blown to adjust the conductivity to 80 mS / cm, and the lithographic printing plate precursor on which the test pattern was drawn in an image shape was developed as before. Further, the electrical conductivity was decreased by 2 mS / cm, and this operation was continued until the stain due to the poorly developed non-image area remaining film was observed.

In these developed plates of Examples and Comparative Examples, the plates developed with each conductivity were checked with a 50 × magnifier to see if there were any stains or coloring due to poorly developed non-image area residual film. The conductivity of the developer that could be developed was determined. Next, the conductivity at which the developed film does not decrease in the unexposed area, specifically, the image density of the solid area before development is measured with a GRETAG reflection densitometer D196 (manufactured by GretagMacbeth), and 0 is determined from this image density. The electric conductivity of the developer having a solid portion having an image density of 10 or more was determined.
The development latitude was defined as the conductivity range of the developer that was able to be developed satisfactorily and the limit of conductivity at which the decrease in the developed film was maintained. The results are shown in Table 1.

〔chemical resistance〕
The exposure patterns of the lithographic printing plate precursors of Examples 1 to 9 and the lithographic printing plate precursors of Comparative Examples 1 to 6 were changed with a Trendsetter 3244 manufactured by Creo, and a test pattern was drawn in an image form. Thereafter, development was performed at a development temperature of 35 ° C. and a development time of 20 seconds using a PS processor 900H manufactured by Fuji Photo Film Co., Ltd. charged with the developer having the composition B. This was continuously printed using a printer Lithron manufactured by Komori Corporation. 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.

  The “specific polymer compound” in Table 1 corresponds to the specific polymer compounds (a) to (h). The “comparative polymer compound” is as shown below.

ｍ／ｎ／ｏ／ｐ＝１７／５６／２／２５；重量平均分子量：１６０００
Ｒ⁰¹＝４−ヒドロキシフェニル基
Ｒ²＝ｎ−ブチル基 <High molecular compound for comparison (i)>

m / n / o / p = 17/56/2/25; weight average molecular weight: 16000
R ⁰¹ = 4-hydroxyphenyl group R ² = n-butyl group

<Comparative polymer compound (j)>
Phenol / m-cresol / p-cresol novolak resin (50/30/20, weight average molecular weight 5,000)
Substitution with specific substituents as described below at a ratio of 10 mol% with respect to the total number of moles of hydroxyl groups.

  As shown in Table 1, each of the lithographic printing plate precursors of Examples 1 to 9 using the specific polymer compound has a wide development latitude and chemical resistance compared to the lithographic printing plate precursors of Comparative Examples 1 to 6. It was found to be excellent in properties.

Claims (1)

The support includes a structural unit represented by the following general formula (I), and part or all of the phenolic hydroxyl group of the structural unit has a lone pair binding site and a hydrogen atom capable of hydrogen bonding. And a heat mode-compatible positive image recording material comprising a recording layer containing a polymer compound modified with a substituent capable of forming two or more thermally reversible hydrogen bonds, and an infrared absorber .

[In General Formula (I), R ⁰¹ represents an aromatic group having a hydroxyl group as a substituent. ]