JPH11338131A - Photosensitive composition and lithographic printing master plate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high sensitivity, good developing latitude and storage stability by preparing a photosensitive compsn. which contains an anionic IR absorbent and a polymer compd. which is insoluble with water, soluble with an alkali aq. soln., and soluble with an alkali aq. soln. by the irradiation of IR laser beam. SOLUTION: This photosensitive compsn. contains an anionic IR absorbent (a) and a polymer compd. (b) which is insoluble with water, soluble with an alkali aq. soln. and soluble with an alkali aq. soln. by the irradiation of IR laser light. The anionic IR absorbent (a) is preferably an anionic metal complex (a-1), anionic carbon black (a-2), anionic phthalocyanine (a-3) or a compd. (a-4) expressed by the formula. In the formula, M is a conjugate chain, Ga <-> is an anionic substituent, Gb is neutral substituent, X<m+> represents 1 to m-valent cation including protons, and m is an integer of 1 to 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition suitable as a positive image forming material and a lithographic printing plate precursor using the same. The present invention relates to a photosensitive composition capable of forming a positive type image for an infrared laser, which is suitable for a lithographic printing plate precursor for so-called direct plate making that can directly make a plate from a digital signal from a computer or the like, and a lithographic printing plate precursor using the same.

[0002]

2. Description of the Related Art In recent years, with the development of solid-state lasers and semiconductor lasers having an emission region from near infrared to infrared, as a system for directly making a plate from digital data of a computer,
Attention has been paid to those using these infrared lasers. A positive type lithographic printing plate material for infrared laser for direct plate making is disclosed in JP-A-7-285275. The present invention is an image recording material in which a substance that absorbs light and generates heat and a positive photosensitive compound such as quinonediazide compounds are added to an aqueous alkali solution-soluble resin, and the positive photosensitive compound is used in an image area. However, it acts as a dissolution inhibitor that substantially lowers the solubility of the aqueous alkali-soluble resin, is decomposed by heat in the non-image area, does not exhibit a dissolution inhibiting ability, and can be removed by development, so that the image can be removed. Form.

As a result of studies by the present inventors, it has been found that a positive image can be obtained without adding a quinonediazide compound to an image recording material. There is a drawback that the stability of the sensitivity to the concentration of the developing solution, that is, the development latitude is deteriorated.

On the other hand, it is known that onium salts and alkali-insoluble compounds capable of hydrogen bonding have an alkali dissolution inhibiting action of alkali-soluble polymers. WO97 / 39894 describes that as an infrared laser-compatible image forming material, a composition using a cationic infrared absorbing dye as a dissolution inhibitor of an alkali water-soluble polymer exhibits a positive effect. This positive action is an action in which an infrared absorbing dye absorbs laser light, and the generated heat eliminates the effect of suppressing the dissolution of the polymer film in the irradiated portion to form an image. Although the image-forming property is sufficient on the laser-irradiated surface of the light-sensitive material, the effect cannot be obtained up to the deep part of the light-sensitive material due to thermal diffusion. There was a problem that it was hard to adhere and a good image could not be obtained (low sensitivity, narrow developing latitude). Here, the development latitude refers to an allowable range in which a good image can be formed when the alkali concentration of the alkali developer is changed.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photosensitive composition which has high sensitivity, good development latitude and good storage stability, and an infrared laser for direct plate making using the same. An object of the present invention is to provide a positive type lithographic printing plate precursor capable of forming an image.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies for the purpose of increasing the image forming property, that is, the sensitivity and the development latitude, and as a result, the use of a specific anionic infrared absorber has led to the use of a white lamp. The present invention was found to be free of light even under the following conditions, and to improve the development latitude, thereby completing the present invention. That is, the photosensitive composition of the present invention comprises (a) an anionic infrared absorber and (b)
It contains a polymer compound that is insoluble in water and soluble in an alkaline aqueous solution (hereinafter, appropriately referred to as an alkaline water-soluble polymer compound), and is made soluble in an alkaline aqueous solution by irradiation with an infrared laser. Features.

Here, the (a) anionic infrared absorber is (a-1) an anionic metal complex, (a-2) anionic carbon black, (a-3) anionic phthalocyanine, or (a- 4) A preferred embodiment is a compound represented by the following general formula (I).

[0008]

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[0009] In the formula, M represents a conjugated chain, G _a ^- represents an anionic substituent, G _b represents a neutral substituent. X ^{m +}
Represents a 1- to m-valent cation containing a proton, where m
Represents an integer of 1 to 6. Further, it is preferable that the counter cation of (a) the anionic infrared absorber has a thermally decomposable onium salt structure.

The lithographic printing plate precursor according to the present invention is provided on a support.
A photosensitive layer comprising the photosensitive composition according to any one of claims 1 to 3 is provided.

Although the function of the present invention is not clear, the use of (a) an anionic infrared absorber allows the counter cation part to act as (b) a dissolution inhibitor for the alkali water-soluble polymer, and In addition, the heat generated by the absorption of the laser light by the anionic infrared absorber can make the dissolution suppressing effect disappear. That is, in the case of a conventionally known cationic infrared absorbing dye, its structure is naturally limited in order to have absorption in the infrared region, and the structure having a dissolution suppressing effect is limited to a range that does not inhibit the absorption capacity in the infrared region, At present, the desired dissolution inhibiting effect cannot be controlled on the molecular structure. When an anionic infrared absorbing agent is used as in the present invention, the counter cation can be freely selected, and the dissolution inhibiting effect can be freely changed without any restriction. It is considered possible to improve

In a more preferred embodiment, (a) when a thermally decomposable onium salt is used as a counter cation of the anionic infrared absorber, the thermally decomposable onium salt is decomposed by the heat generated by the infrared absorber. Because the dissolution suppression effect disappears more quickly and with high sensitivity,
It is considered that high developing latitude image forming ability can be achieved.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [(A) Anionic infrared absorber] In the present invention, the term "anionic infrared absorber" refers to an anion structure in which the mother nucleus of the dye that substantially absorbs infrared light has no cation structure and has an anion structure. For example, (a-1) an anionic metal complex,
(A-2) anionic carbon black, (a-3) anionic phthalocyanine, and (a-4) general formula (I)
And the like. The counter cation of this anionic infrared absorber is a monovalent cation containing a proton or a polyvalent cation. Here, the (a-1) anionic metal complex refers to an anion in which the central metal and the ligand in the complex part which substantially absorbs light become anions. (A-2) Examples of the anionic carbon black include carbon black to which an anionic group such as a sulfonic acid, carboxylic acid, or phosphonic acid group is bonded as a substituent.
To introduce these groups into carbon black, refer to the Carbon Black Handbook, 3rd edition (edited by Carbon Black Association, 19th edition).
As described on page 12 (published by the Carbon Black Association of Japan on April 5, 1995), means such as oxidation of carbon black with a predetermined acid may be used. As described below, an anionic infrared absorber formed by ionic bonding of an onium salt as a counter cation to the anionic group of the anionic carbon black is suitably used in the present invention, but the onium salt is adsorbed to the carbon black. The adsorbed material is not included in the anionic infrared absorbent of the present invention, and the effect of the present invention cannot be obtained with a mere adsorbed material. (A-3) Anionic phthalocyanine refers to an anionic phthalocyanine in which the anion group described in the description of (a-2) is bonded as a substituent to the phthalocyanine skeleton, and the phthalocyanine skeleton is an anion as a whole. Next, the compound (a-4) represented by the general formula (I) will be described. In the general formula (I), M represents a conjugated chain,
This conjugated chain may have a substituent or a ring structure. The conjugated chain M can be represented by the following formula.

[0014]

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In the formula, R _{n + 1} , R _{n + 2} and R _{n + 3} each independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a carbonyl group, And a sulfonyl group, a sulfinyl group, an oxy group, and an amino group, which may be linked to each other to form a ring structure. n shows the integer of 1-8.

[0016] G _a ^- represents an anionic substituent, G _b represents a neutral substituent. X ^{m +} represents a 1- to m-valent cation containing a proton, where m represents an integer of 1 to 6.

When R _{n + 1} , R _{n + 2} , and R _{n + 3} are alkyl groups, the alkyl group is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. No. Specifically, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl,
Eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group, A 2-norbornyl group can be mentioned. Among them, linear alkyl groups having 1 to 12 carbon atoms, branched alkyl groups having 3 to 12 carbon atoms, and cyclic alkyl groups having 5 to 10 carbon atoms are more preferable.

These alkyl groups have a substituent.
The substituent may be a monovalent non-metal atom excluding hydrogen.
A group is used. Preferred examples include a halogen atom
(-F, -Br, -C1, -I), a hydroxyl group,
Lucoxy group, aryloxy group, mercapto group, alkyl
Thio group, arylthio group, alkyldithio group, aryl
Dithio group, amino group, N-alkylamino group, N, N-
Dialkylamino group, N-arylamino group, N, N-
Diarylamino group, N-alkyl-N-arylamido
Group, acyloxy group, carbamoyloxy group, N-A
Alkylcarbamoyloxy group, N-arylcarbamoy
Ruoxy group, N, N-dialkylcarbamoyloxy
Group, N, N-diarylcarbamoyloxy group, N-A
Alkyl-N-arylcarbamoyloxy group, alkyl
Sulfoxy group, arylsulfoxy group, acylthio group,
Acylamino group, N-alkylacylamino group, NA
Reel acylamino group, ureido group, N'-alkyl
Raid group, N ', N'-dialkylureido group, N'-
Arylureido group, N ', N'-diarylureido
Group, N'-alkyl-N'-aryl ureido 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-alkyl
A raid group, an N'-aryl-N-arylureido group,
An N ', N'-diaryl-N-alkylureido group,
An N ', N'-diaryl-N-arylureido group,
N'-alkyl-N'-aryl-N-alkylurei
Group, N'-alkyl-N'-aryl-N-aryl
Ureido group, alkoxycarbonylamino group, arylo
Xycarbonylamino group, N-alkyl-N-alkoxy
Cicarbonylamino group, N-alkyl-N-aryloxy
Cicarbonylamino group, N-aryl-N-alkoxy
Carbonylamino group, N-aryl-N-aryloxy
Carbonylamino, formyl, acyl, carboxyl
A sil group and a conjugate base group thereof (hereinafter referred to as “carboxylar
". ), Alkoxycarbonyl group, aryloxy
Sicarbonyl group, carbamoyl group, N-alkylcarba
Moyl group, N, N-dialkylcarbamoyl group, N-A
Reel carbamoyl group, N, N-diarylcarbamoy
Group, N-alkyl-N-arylcarbamoyl group,
Rukylsulfinyl group, arylsulfinyl group,
Killsulfonyl group, arylsulfonyl group, sulfo group
(-SO_ThreeH) and its conjugate base (hereinafter referred to as “sulfonato
Base. " ), Alkoxysulfonyl group, aryloxy
Disulfonyl group, sulfinamoyl group, N-alkyls
Rufinamoyl group, N, N-dialkylsulfinamoy
Group, N-arylsulfinamoyl group, N, N-dia
Reel sulfinamoyl group, N-alkyl-N-ary
Rusulfinamoyl group, sulfamoyl group, N-alkyl
Rusulfamoyl group, N, N-dialkylsulfamoy
Group, N-arylsulfamoyl group, N, N-diali
Sulfamoyl group, N-alkyl-N-aryls
Rufamoyl group, N-acylsulfamoyl group and the
Conjugated base group, N-alkylsulfonylsulfamoyl group
(-SO_TwoNHSO_TwoR and R represent an alkyl group. )
And its conjugated base group, N-arylsulfonylsulfamo
Il group (-SO_TwoNHSO_TwoAr, Ar is an aryl group
Represent. ) And its conjugated base group, N-alkylsulfonyl
Carbamoyl group (-CONHSO_TwoR and R are alkyl groups
Represents ) And its conjugated base group, N-arylsulfoni
Rucarbamoyl group (-CONHSO_TwoAr, Ar is ant
Represents a hydroxyl group. ) And its conjugated base group, alkoxysilyl
Group (-Si (OR)_Three, R represents an alkyl group. ),
Aryloxysilyl group (-Si (OAr)_Three, Ar is a
Represents a reel group. ), A hydroxysilyl group (—Si (O
H)_Three) And its conjugate base group, phosphono group (one PO_ThreeH
_Two) And its conjugated base group (hereinafter referred to as "phosphonato group")
U. ), A dialkylphosphono group (—PO_ThreeR_Two, R is a
Represents a alkyl group. ), A diarylphosphono group (—PO _Three
Ar_Two, Ar represents an aryl group. ), Alkyl ally
Ruphosphono group (-PO _Three(R) (Ar), R is alkyl
The group Ar represents an aryl group. ) Monoalkylphosphono
Group (-PO_ThreeH (R) and R represent an alkyl group. )as well as
The conjugate base group (hereinafter referred to as “alkyl phosphonate group”)
U. ), Monoarylphosphono group (-PO_ThreeH (A
r) and Ar represent an aryl group. ) And its conjugated base group
(Hereinafter referred to as “arylphosphonato group”), phospho
Nooxy group (-OPO_ThreeH_Two) And its conjugated base group (hereinafter
Below, it is called "phosphonatooxy group". ), Dialkylho
Suphonoxy group (-OPO_Three(R)_TwoAnd R is an alkyl group
Represents ), A diarylphosphonooxy group (—OPO)_Three
(Ar)_Two, Ar represents an aryl group. ), Alkyl
Reel phosphonooxy group (-OPO_Three(R) (Ar),
R represents an alkyl group and Ar represents an aryl group. ), Monoa
Alkylphosphonooxy group (-OPO_ThreeH (R), R is a
Represents a alkyl group. ) And its conjugated base group (hereinafter referred to as “Al
"Kilphosphonatooxy group". ), Monoarylho
Suphonoxy group (-OPO_ThreeH (Ar) Ar is aryl
Represents a group. ) And its conjugated base group (hereinafter referred to as “allylpho
"Shonatooxy group". ), Cyano, nitro,
Aryl group, alkenyl group, alkynyl group
You. Specific examples of the alkyl group in these substituents
And the above-mentioned (1) alkyl group)
Specific examples of the phenyl group include a phenyl group, a biphenyl group,
Phthyl, tolyl, xylyl, mesityl, cumeni
Group, fluorophenyl group, chlorophenyl group, bromo
Phenyl group, chloromethylphenyl group, hydroxyphen
Nil group, methoxyphenyl group, ethoxyphenyl group,
Phenoxyphenyl, acetoxyphenyl, benzoy
Roxyphenyl group, methylthiophenyl group, phenylthio
Ophenyl group, methylaminophenyl group, dimethylamino
Nophenyl group, acetylaminophenyl group, carboxy
Phenyl group, methoxycarbonylphenyl group, ethoxy
Carbonylphenyl group, phenoxycarbonylphenyl
Group, N-phenylcarbamoylphenyl group, phenyl
Group, nitrophenyl group, cyanophenyl group, sulfofe
Nyl group, sulfonatophenyl group, phosphonophenyl group,
And a phosphonatophenyl group. Also,
Examples of the alkenyl group include a vinyl group, 1-propenyl
Group, 1-butenyl group, cinnamyl group, 2-chloro-1-
An ethenyl group, and the like, and as an example of the alkynyl group,
Is an ethynyl group, a 1-propynyl group, a 1-butynyl group,
Trimethylsilylethynyl group, phenylethynyl group, etc.
No. The acyl group (R¹As CO-),
R¹Is a hydrogen atom and the aforementioned alkyl group, aryl group,
Examples include a alkenyl group and an alkynyl group.

Of these substituents, more preferred are a halogen atom ((-F, -Br, -C1,-
I), an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an N-alkylamino group, N, N-
Dialkylamino group, acyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, acylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group , N, N-dialkylcarbamoyl, N-arylcarbamoyl, N-alkyl-N-arylcarbamoyl, sulfo, sulfonato, sulfamoyl,
N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N-
Alkyl-N-arylsulfamoyl group, phosphono group, phosphonate group, dialkylphosphono group, diarylphosphono group, monoalkylphosphono group, alkylphosphonato group, monoarylphosphono group, arylphosphonato group, phosphonooxy group , A phosphonatoxy group, an aryl group, an alkenyl group and the like.

On the other hand, examples of the alkylene group in the substituted alkyl group include those obtained by removing any one of the aforementioned hydrogen atoms on the alkyl group having 1 to 20 carbon atoms to obtain a divalent organic residue. And preferably has 1 carbon atom
And C 12 to C 12, C 3 to C 12 branched and C 5 to C 10 cyclic alkylene groups. Preferred specific examples of the substituted alkyl group obtained by combining the substituent with an alkylene group include a chloromethyl group, a bromomethyl group, a 2-chloroethyl group, a trifluoromethyl group, a methoxymethyl group, a methoxyethoxyethyl group, and an allyloxy group. Methyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N-phenyl Carbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, methoxycal Nylmethyl group, methoxycarbonylbutyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylgarbamoylmethyl group, N- (methoxyphenyl) galbamoyl Ethyl group,
N-methyl-N- (sulfophenyl) galbamoylmethyl group, sulfopropyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group , N-tolylsulfamoylpropyl group, N
A -methyl-N- (phosphonophenyl) sulfyloctyl group,

Phosphonobutyl, phosphonatohexyl, diethylphosphonobutyl, diphenylphosphonopropyl, methylphosphonobutyl, methylphosphonatobutyl, tolylphosphonohexyl, tolylphosphonatohexyl, phosphonooxy Propyl group, phosphonatoxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p
-Methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, etc. Can be mentioned.

When R _{n + 1} , R _{n + 2} , and R _{n + 3} are an aryl group, the aryl group may be one in which one to three benzene rings form a condensed ring, Examples thereof include those in which a saturated ring forms a condensed ring.Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenabutenyl group, and a fluorenyl group. , A phenyl group and a naphthyl group are more preferred.

As the substituted aryl group, those having a monovalent nonmetallic atomic group other than hydrogen as a substituent on the ring-forming carbon atom of the aforementioned aryl group are used. Examples of preferred substituents include the above-mentioned alkyl groups, substituted alkyl groups,
Examples of the substituent for the substituted alkyl group include those described above. Preferred specific examples of such a substituted aryl group include a biphenyl group, a tolyl group, a xylyl group, a mesityl group, a cumenyl group, a chlorophenyl group, a bromophenyl group, a fluorophenyl group, a chloromethylphenyl group, and a trifluoromethylphenyl group. A hydroxyphenyl group, a methoxyphenyl group, a methoxyethoxyphenyl group, an allyloxyphenyl group, a phenoxyphenyl group, a methylthiophenyl group, a tolylthiophenyl group, a phenylthiophenyl group, an ethylaminophenyl group, a diethylaminophenyl group, a morpholinophenyl group, Acetyloxyphenyl group, benzoyloxyphenyl group, N
-Cyclohexylcarbamoyloxyphenyl group, N-
Phenylcarbamoyloxyphenyl group, acetylaminophenyl group, N-methylbenzoylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, galbamoylphenyl group, N-methylgalbamoyl Phenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) galbamoylphenyl group, N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoyl Phenyl, N-ethylsulfamoylphenyl, N, N-dipropylsulfamoylphenyl, N-tolylsulfamoylphenyl, N-methyl-N- (phosphonophenyl) sulfamoylphenyl Nyl, phosphonophenyl, phosphonatophenyl, diethylphosphonophenyl, diphenylphosphonophenyl, methylphosphonophenyl, methylphosphonatophenyl, tolylphosphonophenyl, tolylphosphonatophenyl, allyl Group, 1-propenylmethyl group, 2-butenyl group, 2-methylallylphenyl group, 2-methylpropenylphenyl group, 2-propynylphenyl group, 2-butynylphenyl group, 3-butynylphenyl group, and the like. be able to.

An alkenyl group represented by R _{n + 1} , R _{n + 2} and R _{n + 3} ;
Substituted alkenyl group, an alkynyl group, substituted alkynyl group ^{(-C (R 7) = C} (R 8) (R 9), and -C≡C
As (R ¹⁰ ), those in which R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are monovalent nonmetallic atomic groups can be used. Preferred R ⁷ , R ⁸ ,
Examples of R ⁹ and R ¹⁰ include a hydrogen atom, a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group. As specific examples thereof, those shown as the above examples can be similarly mentioned. Examples of preferred substituents of R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ include a hydrogen atom, a halogen atom, and a C 1-10 carbon atom.
Linear, branched and cyclic alkyl groups. Specific examples of such R _{n + 1} , R _{n + 2} , R _{n + 3} include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group,
Decyl group, undecyl group, dodecyl group, tridecyl group,
Hexadecyl group, otatadecyl group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, allyl group, 1-propenyl Methyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, benzyl group,
Phenethyl group, α-methylhensyl group, 1-methyl-1
-Phenethyl group, p-methylbenzyl group, cinnamyl group, hydroxyethyl group, methoxyethyl group, phenoxydiethyl group, allyloxyethyl group, methoxyethoxyethyl group, ethoxyethoxyethyl group, morpholinoethyl group, morpholinopropyl group, sulfopropyl Group, sulfonatopropyl group, sulfobutyl group, sulfonatobutyl group / carboxydimethyl group, carboxydiethyl group, carboxypropyl group, methoxycarbonylethyl group, 2-ethylhexyloxycarbonylethyl group, phenoxycarbonylmethyl group, methoxycarbonylpropyl group, N-
Methylcarbamoylethyl group, N, N-ethylaminocarbamoylmethyl group, N-phenylcarbamoylpropyl group, N-tolylsulfamoylbutyl group, P-trienesulfonylaminopropyl group, benzoylaminohexyl group, phosphonomethyl group, phos Phonoethyl group, phosphonopropyl group, p-phosphonobenzylaminocarbonylethyl group, phosphonatomethyl group, phosphonatopropyl group, phosphonatobutyl group, p-phosphonatobenzylaminocarbonylethyl group, vinyl group, ethynyl group Can be mentioned.

As the substituted carbonyl group (R ¹¹ CO-) for R _{n + 1} , R _{n + 2} and R _{n + 3} , those wherein R ¹¹ is a monovalent nonmetallic atomic group can be used. Preferred examples of the substituted carbonyl group include formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, An N, N-diarylcarbamoyl group,
And N-alkyl-N-arylcarbamoyl groups. Examples of the alkyl group and aryl group in these include those exemplified as the above-described alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Among these, more preferred substituents include
Formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, galbamoyl group, N-alkylgalbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, and even more preferable ones. Examples include a formyl group, an acyl group, an alkoxycarbonyl group and an aryloxycarbonyl group. Specific examples of preferred substituents include formyl, acetyl, benzoyl, carboxyl, methoxycarbonyl, allyloxycarbonyl, N-methylcarbamoyl, N-phenylcarbamoyl, N, N-diethylcarbamoyl, And a morpholinocarbonyl group.

As the substituted thio group (R ¹⁴ S-), those in which R ¹⁴ is a monovalent nonmetallic atomic group excluding hydrogen can be used. Preferred examples of the substituted thio group include an alkylthio group, an arylthio group, an alkyldithio group, an aryldithio group, and an acylthio group. Alkyl group in these alkyl groups Said aryl group, a substituted alkyl group, an aryl group, and can be those exemplified as the substituted aryl group, R ¹³ of the acyl group in the acylthio group (R ¹³ CO-) in As described above. Among these, an alkylthio group and an arylthio group are more preferred. Specific examples of preferred substituted thio groups include a methylthio group, an ethylthio group, a phenylthio group, an ethoxyethylthio group, a carboxyethylthio group, and a methoxycarbonylthio group.

As the substituted sulfonyl group (R ¹⁹ SO ₂ —), those in which R ¹⁹ is a monovalent nonmetallic atomic group can be used. More preferred examples include an alkylsulfonyl group and an arylsulfonyl group. Examples of the alkyl group and aryl group in these include those exemplified as the above-described alkyl group, substituted alkyl group, aryl group, and substituted aryl group.
Specific examples of the substituted sulfonyl group include a butylsulfonyl group and a chlorophenylsulfonyl group.

As the substituted sulfinyl group (R ¹⁸ SO—), those in which R ¹⁸ is a monovalent nonmetallic atomic group can be used. Preferred examples include an alkylsulfinyl group, an arylsulfinyl group, a sulfinamoyl group, N
-Alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group,
An N, N-diarylsulfinamoyl group and an N-alkyl-N-arylsulfinamoyl group are exemplified. Examples of the alkyl group and aryl group in these include those exemplified as the above-described alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Among these, more preferred examples include an alkylsulfinyl group and an arylsulfinyl group. Specific examples of such a substituted sulfinyl group include a hexylsulfinyl group, a benzylsulfinyl group, and a tolylsulfinyl group.

As the substituted oxy group (R ¹² O—), R ¹²
Is a monovalent non-metallic atomic group other than hydrogen. Preferred substituted oxy groups include an alkoxy group, an aryloxy group, an acyloxy group, a carbamoyloxy group, an N-alkylcarbamoyloxy group, an N-arylcarbamoyloxy group, an N, N-dialkylcarbamoyloxy group, and an N, N-diarylcarbamoyloxy group. Group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group,
Examples include a phosphonooxy group and a phosphonatoxy group.
Examples of the alkyl group and the aryl group in these include those exemplified above as the alkyl group, the substituted alkyl group, the aryl group, and the substituted aryl group. Further, an acyl group (R ¹³ CO
Examples of —) include those in which R ¹³ has been exemplified as the aforementioned alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Among these substituents, an alkoxy group, an aryloxy group, an acyloxy group, and an arylsulfoxy group are more preferred. Specific examples of preferred substituted oxy groups include methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, pentyloxy, hexyloxy, dodecyloxy, benzyloxy, allyloxy, phenethyloxy, Carboxyethyloxy group, methoxycarbonylethyloxy group, ethoxycarbonylethyloxy group, methoxyethoxy group, phenoxyethoxy group, methoxyethoxyethoxy group, ethoxyethoxyethoxy group, morpholinoethoxy group, morpholinopropyloxy group, allyloxyethoxy group, Phenoxy group, tolyloxy group, xylyloxy group, mesityloxy group,
Examples include a cumenyloxy group, a methoxyphenyloxy group, an ethoxyphenyloxy group, a chlorophenyloxy group, a bromophenyloxy group, an acetyloxy group, a benzoyloxy group, a naphthyloxy group, a phenylsulfonyloxy group, a phosphonooxy group, and a phosphonatoxy group.

A substituted amino group (R ¹⁵ NH—, (R ¹⁶ ) (R
¹⁷ ) As N-), those in which R ¹⁵ , R ¹⁶ and R ¹⁷ are monovalent nonmetallic atomic groups other than hydrogen can be used.
Preferred examples of the substituted amino group include N-alkylamino, N, N-dialkylamino, N-arylamino, N, N-diarylamino, N-alkyl-N
-Arylamino group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N'-alkylureido group, N ', N'-dialkylureido group, N'-arylureido group, N ', N'
-A diarylureido group, an N'-alkyl-N'-arylureido group, an N-alkylureido group, an N-arylureido group, an N'-alkyl-N-alkylureido group, an N'-alkyl-N-arylureido group , N ',
An 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, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N- Examples include an aryloxycarbonylamino group, an N-aryl-N-alkoxycarbonylamino group, and an N-aryl-N-aryloxycarbonylamino group.
Examples of the alkyl group and the aryl group in these include the above-described alkyl group, substituted alkyl group, aryl group, and those exemplified as the substituted aryl group.
Acylamino group, N- alkylacylamino group, N- aryl - acyl group in acylamino group (R ¹³ CO
R13 ^in- ) is as described above. Of these, more preferred are N-alkylamino group, N, N
-Dialkylamino group, N-arylamino group, acylamino group. Specific examples of preferred substituted amino groups include a methylamino group, an ethylamino group, a diethylamino group, a morpholino group, a piperidino group, a pyrrolidino group, a phenylamino group, a benzoylamino group, an acetylamino group, and the like.

Further, in the general formula (I), G _a ^-
Represents an anionic substituent, G _b is a table a neutral substituent, these may be respectively represented by the following structure.

[0032]

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In the formula, L _{1 to} L ₄ each independently represent a hydrogen atom, a halogen, a cyano group and the above-mentioned alkyl, aryl, alkenyl, alkynyl, carbonyl,
Examples thereof include a thio group, a sulfonyl group, a sulfinyl group, an oxy group, and an amino group. L ₁ and L ₂ , and L ₃ and L ₄ may be linked to form a ring structure. G as a preference
_b acidic nucleus of the cyanine dye, also G _a ^- include those acidic nucleus is anionized. As the acidic nucleus, "Th
e teory of the Photograph
ic Process, p. 199, Tables 8, 2
-B and the following compounds.

1) 1,3-dicarbonyl nucleus, for example, 1,
3-indandione, 1,3-cyclohexanedione,
5,5-dimethyl-1,3-cyclohexanedione,
1,3-dioxane-4,6-dione, 2) pyrazolinone nucleus, for example, 3-methyl-1-phenyl-2-pyrazolin-5-one, 1-phenyl-2-pyrazolin-5-one, 1-phenyl- 2-pyrazolin-5
-One, 1- (2-benzothiazolyl) -3-methyl-
2-pyrazolin-5-one, 3) isoxazolinone nucleus, for example, 3-phenyl-2-
4) Oxindole nucleus, for example, 1-alkyl-2,3, such as isoxazolin-5-one and 3-methyl-2-isoxazolin-5-one.
-Dihydro-2-oxindole,

5) 2,4,6-Triketohexahydropyrimidine nucleus, for example, barbituric acid or 2-thiobarbituric acid and derivatives thereof, such derivatives include 1-alkyl compounds such as 1-methyl and 1-ethyl; 1,3-dialkyl compounds such as 1,3-diethyl and 1,3-dibutyl,
3-diphenyl, 1,3-di (p-chlorophenyl)
And 1,3-diaryl compounds such as 1,3-di (p-ethoxycarbonylphenyl) and 1-alkyl-3-aryl compounds such as 1-ethyl-3-phenyl. 6) 2-thio-2,4-thiazolidinedione nucleus such as rhodanine and its derivatives, such derivatives include 3-
Examples include 3-alkyl rhodanines such as ethyl rhodanine and 3-allyl rhodanine, and 3-aryl rhodanines such as 3-phenyl rhodanine.

7) 2-thio-2,4-oxazolidinedione (2-thio-2,4- (3H, 5H) -oxazoledione) nucleus, for example, 2-ethyl-2-thio-2,4-
Oxazolidinedione, 8) thianaphthenone nucleus, such as 3 (2H) -thianaphthenone and 3 (2H) -thianaphthenone-1,1-dioxide, 9) 2-thio-2,5-thiazolidinedione nucleus, such as 3-ethyl-2 -Thio-2,5-thiazolidinedione, 10) 2,4-thiazolidinethione nucleus, for example, 2,4-
Thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, 3-phenyl-2,4-thiazolidinedione, 11) thiazolidinone nucleus such as 4-thiazolidinone,
3-ethyl-4-thiazolidinone,

12) 4-thiazolinone nucleus, for example, 2-ethylmercapto-5-thiazolin-4-one, 2-alkylphenylamino-5-thiazolin-4-one, 13) 2-imino-2-oxozoline-4- On (coagulation hydantoin) nucleus, 14) 2,4-Imidazolidinedione (hydantoin)
A nucleus, for example, 2,4-imidazolidinedione, 3-ethyl-2,4-imidazolidinedione, 15) 2-thio-2,4-imidazolidinedione (2-
Thiohydantoin) nucleus, for example 2-thio-2,4-imidazolidinione, 3-ethyl-2-thio-2,4-imidazolidinedione, 16) 2-imidazolin-5-one nucleus, for example 2-n-
Propyl-mercapto-2-imidazolin-5-one,

17) Furan-5-one, 18) 4-hydroxy-2 (1H) -quinolinone nucleus or 4-hydroxy-2 (1H) -pyridinone nucleus such as N-methyl-4-hydroxy-2 (1H) -Quinolinone, N-n-butyl-4-hydroxy-2 (1H) -quinolinone, N-methyl-4-hydroxy-2 (1H)-
Pyridinone, 19) substituted or unsubstituted 4-hydroxy-2H-pyran-2-one, 4-hydroxycoumarin; 20) substituted or unsubstituted thioindoxyl, such as 5-methylthioindoxyl.

In the general formula (I), Z represents a chalcogen atom or a —C (Y ₁ ) (Y ₂ ) group. Where Y
₁ and Y ₂ may be the same and different, and —CN, —CO ₂
R ′, —SO ₂ R ″. R ′ and R ″ represent the same alkyl group and aryl group as described above.

In a preferred embodiment of the anionic infrared absorbing agent, the counter cation has a positive image forming action, and examples of such a counter ion include those having an onium salt structure. Here, as the onium salt,
Examples thereof include ammonium salts, diazonium salts, oxonium salts, sulfonium salts, selenium salts, phosphonium salts, carbonium salts, iodonium salts and the like.

Suitable onium salts used in the present invention include, for example, SI Schlesinger,
Photogr. Sci. Eng., 18, 387 (1974), TS Bal et a
1, Polymer, 21, 423 (1980), JP-A-5-158230
Diazonium salts described in U.S. Pat.
Nos. 9,055 and 4,069,056;
Ammonium salt described in the specification of No. 40140, DC
Necker et al, Macromolecules, 17, 2468 (1984), C.
S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p
478 Tokyo, Oct (1988), US Patent 4,069,05.
No. 5,069,056, JV Crivello et al, Macromorecules, 10 (6), 13
07 (1977), Chem. & Eng. News, Nov. 28, p31 (198
8), EP 104,143, U.S. Pat.
No. 049, No. 410,201, JP-A-2-1508
No. 48, iodonium salts described in JP-A-2-296514, JV Crivello et al, Polymer J. 17, 73 (198
5), JV Crivello et al. J. Org. Chem., 43, 3055
(1978), WR Watt et al, J. Polymer Sci., Polymer
Chem. Ed., 22, 1789 (1984), JV Crivello et a
l, Polymer Bull., 14, 279 (1985), JV Crivello
et al, Macromorecules, 14 (5), 1141 (1981), JVCr
ivello et al, J. Polymer Sci., Polymer Chem. Ed.,
17, 2877 (1979), EP 370,693, 2
33,567, 297,443, 297,44
No. 2, U.S. Pat. Nos. 4,933,377 and 3,90
Nos. 2,114, 410,201, 339,049
No. 4,760,013, 4,734,444
No. 2,833,827, German Patent No. 2,904,
626, 3,604,580, 3,604,5
No. 81, JV Crivello et al,
Macromorecules, 10 (6), 1307 (1977), JV Crivell
o et al, J. Polymer Sci., Polymer Chem. Ed., 17, 1
047 (1979), selenonium salts, CS Wen et a
l, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo,
And arsonium salts described in Oct (1988).

Further, ammonium salts, phosphonium salts, sulfonium salts, iodonium salts and the like described in JP-A-9-134409 can be preferably used in the present invention.

The oxonium salt is represented by the following general formula (A) or (B).

[0044]

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Where R_a~ R_dAre independent of each other
And an aryl group._eIs an alkylene group, aryl
Represents a len group. In addition, adjacent R_a~ R_cOr R_d
And R _eMay combine with each other to form a ring structure.

The selenium salt is represented by the following general formula (C) or (D).

[0047]

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Where R_f~ R_iAre independent of each other
And an aryl group._jIs an alkylene group, aryl
Represents a len group. In addition, adjacent R_f~ R_gOr R_i
And R _jMay combine with each other to form a ring structure.

The diazonium salt is represented by the following general formula (E).

[0050]

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In the formula, R _k represents an alkyl group or an aryl group.

The carbonium salt is represented by the following general formula (F) or general formula (G).

[0053]

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Where R_l~ R_oAre independent of each other
And an aryl group._pIs an alkylene group, aryl
Represents a len group. In addition, adjacent R_l~ R_mOr R_o
And R _pMay combine with each other to form a ring structure.

Other preferred onium salts include those represented by the following general formulas (H) to (K).

[0056]

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In the above formula, R^A, R^B, R^C, R^D,
R^J, R^K, R^LAnd R^MAre each independently alkyl
Group, an aryl group or an aralkyl group,^A, R^B,
R^CAnd R ^DMay combine with each other to form a ring
K, R^J, R^K, R^LAnd R^MAre connected to each other to form a ring
May be formed. R^E, R^FAnd R^GAre independent
Represents an alkyl group or an aryl group;^E, R^Fas well as
R^GAnd may combine with each other to form a ring. R^H
And R^IEach independently represents an alkyl group.

As a more preferred example, an embodiment in which the counter cation is a thermally decomposable onium salt is given. In the present invention, a thermally decomposable onium salt is one which has a decomposition of 10 when measured using a differential thermal / thermogravimetric analysis or a melting point analyzer.
The onium salt having a temperature of 200% by mol or less is referred to as onium salt. Such a thermally decomposable onium salt can be easily obtained by changing the substituent of the onium salt. As the thermally decomposable onium salt used here, as long as it satisfies the above requirements of thermal decomposability, ammonium salt, diazonium salt, oxonium salt, sulfonium salt, selenium salt, phosphonium salt, carbonium salt,
Any of iodonium salts and the like may be used.

Specific examples of the anionic infrared absorbing agent are shown below, but the present invention is not limited thereto.

[0060]

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These can be synthesized by a known method. For example, the anionic Ni complex (AD-1 ⁻ , A
D-2 ^-..) Is the journal of the American Chemical Society (J. of American Chem Soc) Volume 88, 196
It can be synthesized according to the method described in pages 43-50 or 4870-4875 of the 6th year. Also, the anionic carbon black (AD-3 ^-), the carbon black Handbook (edited by Carbon Black Association, 1995, published by Carbon Black Association) was introduced carboxylic group by oxidation as described in page 12, Things.

(A-4) Among the compounds represented by the general formula (I), the anionic dye skeleton can be represented by the following general formula (II).

[0063]

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Here, θ, α, and φ are variables, respectively.
The specific structure of the anionic dye skeleton can be shown by a combination of the respective partial structures G _a θ, Mαφ, and G _b θ. For example, the partial structures G _a1 , Mf3, G _b 2
Are as follows,

[0065]

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The anionic dye skeleton obtained by combining these has the following structure.

[0067]

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Examples of the partial structure of the anionic dye skeleton of the present invention, specific examples of onium salts preferable as counter ions, and examples (A1 to A39) of suitable anionic infrared absorbers obtained by combining them are shown below. However, the present invention is not limited to these specific examples. Partial structure G _a
Examples of θ include the following.

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[0070]

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The following are examples of the partial structure G _b θ.

[0072]

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[0073]

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The following are examples of the methine chain Mαφ.

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[0076]

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When the methine chain Mαφ has a substituent, examples of the substituent φ-Y include the following.

[0078]

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[0079]

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Examples of suitable counter cation partial structures represented by the general formulas (A) to (G) include the following.

[0081]

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Examples of suitable counter cation partial structures represented by the general formula (H) include the following.

[0083]

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Examples of suitable counter cation partial structures represented by the general formula (I) include the following.

[0085]

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[0086]

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Examples of suitable counter cation partial structures represented by the general formula (J) include the following.

[0088]

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[0089]

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Examples of suitable counter cation partial structures represented by the general formula (K) include the following.

[0091]

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[0092]

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Examples of suitable anionic infrared absorbing agents include the following (A1 to A39).

[0094]

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[0095]

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[0096]

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[0097]

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[0098]

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[0099]

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[0100]

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[0101]

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[0102]

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[0103]

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[0104]

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[0105]

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In the present invention, these anionic infrared absorbers are used in an amount of 0.0 to 0.05% of the total solid content of the photosensitive composition.
It can be added at a rate of 1 to 50% by weight, preferably 0.1 to 20% by weight, more preferably 0.5 to 15% by weight. If the addition amount is less than 0.01% by weight, an image cannot be formed by the photosensitive composition. There is a possibility that the image portion is stained.
To the photosensitive composition of the present invention, in addition to the infrared absorbing agent, a pigment or a dye having another infrared absorbing property can be added for the purpose of improving image forming properties. Examples of the pigment include commercially available pigments and color indexes (C.I.
I. ) Handbook, "Latest Pigment Handbook" (edited by Japan Pigment Technology Association,
1977), “Latest Pigment Application Technology” (CMC Publishing,
1986), "Printing Ink Technology", CMC Publishing, 19
1984) can be used.

The types of pigments include black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment,
Blue pigment, green pigment, fluorescent pigment, metal powder pigment, etc.
Polymer-bound dyes. Specifically, insoluble azo pigments, azo lake pigments, condensation azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments,
Perylene and perinone pigments, thioindigo pigments,
Quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, dye lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like can be used.

These pigments may be used without being subjected to a surface treatment, or may be used after being subjected to a surface treatment. Methods of surface treatment include a method of surface-coating a resin or wax, a method of attaching a surfactant, and a reactive substance (for example, a silane coupling agent, an epoxy compound, or a polyisocyanate).
Can be conceived on the surface of the pigment. The above surface treatment methods are described in "Properties and Applications of Metallic Soap" (Koshobo),
"Printing ink technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986)
It is described in.

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm.
Is preferably within the range. Pigment particle size 0.01μ
When it is less than m, the dispersion is not preferred in terms of stability in a photosensitive layer coating solution, and when it exceeds 10 μm, it is not preferred in terms of uniformity of the photosensitive layer. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Dispersers include ultrasonic dispersers, sand mills, attritors, pearl mills, super mills,
Examples include a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. For details, see “Latest Pigment Application Technology”
(CMC Publishing, 1986).

As the dye, commercially available dyes and known dyes described in literatures (for example, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, published in 1970) can be used. Specific examples include azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, and cyanine dyes. In the present invention, among these pigments or dyes, those that absorb infrared light or near-infrared light are particularly preferable because they are suitable for use in lasers that emit infrared light or near-infrared light.

As such a pigment absorbing infrared light or near infrared light, carbon black is preferably used. Dyes that absorb infrared light or near infrared light include, for example, JP-A-58-125246 and JP-A-59-125246.
-84356, JP-A-59-202829, JP-A-60-78787 and the like.
JP-A-58-173696, JP-A-58-18169
0, methine dyes described in JP-A-58-194595, JP-A-58-112793, and JP-A-58-112793.
Naphthoquinone dyes described in JP-A-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744 and the like; And the like, a cyanine dye described in British Patent No. 434,875, a dihydroperimidine squarylium dye described in U.S. Pat. No. 5,380,635, and the like.

Further, as a dye, US Pat. No. 5,156,
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645 (U.S. Pat. No. 4,327,169), a trimethinethiapyrylium salt described in JP-A-58-1810.
No. 51, No. 58-220143, No. 59-41363
Nos. 59-84248, 59-84249, 59-146063, and 59-146061 and pyrylium compounds described in JP-A-59-2161.
No. 46, a cyanine dye disclosed in U.S. Pat. No. 4,283,4.
No. 75, pentamethine thiopyrylium salt and the like, and pyrilium compounds disclosed in Japanese Examined Patent Publication Nos. 5-135514 and 5-19702, Epollight III-1
78, Epollight III-130, Epollight
t III-125, Epollight IV-62A and the like are particularly preferably used.

Another particularly preferred example of the dye is a near-infrared absorbing dye described as formulas (I) and (II) in US Pat. No. 4,756,993. These pigments or dyes are used in an amount of 0.01 to 50% by weight, preferably 0.1 to 10% by weight, particularly preferably 0.5 to 10% by weight, in the case of dyes, Particularly preferred is 3.1.
It can be added to the printing plate material at a ratio of 10 to 10% by weight. If the amount of the pigment or dye is less than 0.01% by weight, the sensitivity is lowered. If the amount exceeds 50% by weight, the uniformity of the photosensitive layer is lost and the durability of the recording layer is deteriorated.

These dyes or pigments may be added to the photosensitive composition and added to the photosensitive layer together with other components, or in preparing a lithographic printing plate precursor, another layer other than the photosensitive layer may be provided. It may be added. These dyes or pigments may be used alone or in combination of two or more.

[(B) Alkaline aqueous solution soluble resin]
(B) Alkaline aqueous solution soluble polymer compound to be used
The substance is, as follows, in the main chain or side chain of the polymer compound.
It refers to those having an acid group structure. Phenolic hydroxyl group (-
Ar-OH), carboxylic acid group (-CO_ThreeH), sulfone
Acid group (-SO_ThreeH), phosphate group (-OPO_ThreeH), Sur
Honamide group (-SO _TwoNH-R), substituted sulfonamido
Acid group (active imide group) (-SO_TwoNHCOR, -S
O_TwoNHSO_TwoR, -CONHSO_TwoR). Where A
r represents a divalent aryl group which may have a substituent;
R has a hydrocarbon group which may have a substituent
You. Among them, preferred acid groups include (b-1) pheno
Hydroxyl group, (b-2) sulfonamide group, (b-
3) An active imide group, particularly (b-1) phenol
Alkaline aqueous solution soluble resin having a hydroxyl group
It is referred to as "a resin having a phenolic hydroxyl group". ) Is the most
It can be preferably used.

(B-1) Examples of the high molecular compound having a phenolic hydroxyl group include polycondensates of phenol and formaldehyde (hereinafter, referred to as "phenol formaldehyde resin") and degeneracy of m-cresol and formaldehyde. (Hereinafter referred to as "m-cresol formaldehyde resin"), a condensation polymer of p-cresol and formaldehyde, a condensation polymer of m- / p-mixed cresol and formaldehyde, phenol and cresol (m-, p- Or a m- / p-mixture) and a novolak resin such as a condensation polymer of formaldehyde, and a condensation polymer of pyrogallol and acetone. Alternatively, a copolymer obtained by copolymerizing a monomer having a phenol group in a side chain can be used. As the monomer having a phenol group to be used,
Examples thereof include acrylamide, methacrylamide, acrylate, methacrylate, and hydroxystyrene having a phenol 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-hydroxyphenyl methacrylate, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (2-hydroxyphenyl) ethyl acrylate 2- (3-hydroxyphenyl) ethyl acrylate, 2- (4-hydroxyphenyl) ethyl acrylate, 2- (2-hydroxyphenyl) ethyl meth Relate, 2- (3-hydroxyphenyl) ethyl methacrylate can be suitably used 2- (4-hydroxyphenyl) ethyl methacrylate. The weight average molecular weight of the polymer is 5.0 × 10
^{2 to} 2.0 × 10 ⁴ and a number average molecular weight of 2.0 × 10 ²
Those having a size of from 1.0 to 10 ⁴ are preferable in view of image forming properties. Moreover, not only these resins are used alone, but also
A combination of more than two types may be used. When used in combination, a C3-C8 polymer such as a condensation polymer of t-butylphenol and formaldehyde or a condensation polymer of octylphenol and formaldehyde as described in U.S. Pat. No. 4,123,279. A condensation polymer of phenol and formaldehyde having an alkyl group as a substituent may be used in combination.

The resin having a phenolic hydroxyl group preferably has a weight average molecular weight of 500 to 20,000 and a number average molecular weight of 200 to 10,000. Further, as described in U.S. Pat. No. 4,123,279, a condensate of phenol having a C3-8 alkyl group as a substituent and formaldehyde, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin. May be used in combination. The resin having such a phenolic hydroxyl group may be one type or two types.
A combination of more than two types may be used.

In the case of (b-2) an alkali water-soluble polymer compound having a sulfonamide group, the main monomer constituting the polymer compound is (a-2) a monomer having a sulfonamide group in one molecule. Examples of the monomer include a low-molecular compound having a sulfonamide group in which at least one hydrogen atom is bonded to a nitrogen atom and one or more polymerizable unsaturated bonds. Among them, a low molecular compound having an acryloyl group, an allyl group, or a vinyloxy group and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group is preferable. Examples of such compounds include compounds represented by the following general formulas (3) to (7).

[0119]

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Where X¹, X^TwoIs -O- or-
NR¹⁷Indicates-. R^{twenty one}, R^{twenty four}Is a hydrogen atom or-
CH_ThreeRepresents R^{twenty two}, R^{twenty five}, R²⁹, R³², R³⁶Each
Alkylene having 1 to 12 carbon atoms which may have a substituent
Group, cycloalkylene group, arylene group or aralkyl
Represents a len group. R^{twenty three}, R²⁷, R³³Are hydrogen atoms, respectively
C1-C12 alkyl which may have a substituent
Group, cycloalkyl group, aryl group or aralkyl group
Show. Also, R²⁶, R²⁷Has a substituent
C1-C12 alkyl group, cycloalkyl
Group, an aryl group, and an aralkyl group. R²⁸, R³⁰, R
³⁴Is a hydrogen atom or -CH_ThreeRepresents R³¹, R³⁵Each
1 to 12 carbon atoms which may have a single bond or a substituent
Alkylene group, cycloalkylene group, arylene group or
Represents an aralkylene group. Y¹, Y ^TwoIs a single bond
Or -CO-.

More specifically, m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be suitably used.

(B-3) In the case of an alkali water-soluble polymer compound having an active imide group, the compound has an active imide group represented by the following formula in the molecule, and is a main monomer constituting the polymer compound. (B-3) As a monomer having an active imide group, a monomer comprising a low-molecular compound having an active imino group represented by the following formula and one or more polymerizable unsaturated bonds in one molecule. Is mentioned.

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Specific examples of such a compound include:
N- (p-toluenesulfonyl) methacrylamide, N
-(P-Toluenesulfonyl) acrylamide and the like can be suitably used.

In the alkali water-soluble copolymer which can be used in the present invention, the monomers containing the acidic groups (b-1) to (b-3) need not be one kind, but have the same acidic group. Those obtained by copolymerizing two or more monomers or two or more monomers having different acidic groups can also be used. As a copolymerization method, a conventionally known graft copolymerization method, block copolymerization method, random copolymerization method, or the like can be used.

The copolymer is copolymerized (b-1)
To (b-3) preferably contains at least 10 mol% of a monomer having an acidic group as a copolymer component.
Those containing at least mol% are more preferred. 10 copolymer components
If the amount is less than mol%, the interaction with the resin having a phenolic hydroxyl group becomes insufficient, and the effect of improving the development latitude, which is an advantage of using a copolymer component, becomes insufficient.

The copolymer (b-1)
To (b-3) other than the monomer containing an acidic group. As examples of the monomer that can be used as the copolymer component, the following monomers (1) to (12) can be used.

(1) Acrylic esters having an aliphatic hydroxyl group, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, and methacrylic esters. (2) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl Alkyl acrylates such as acrylates; (3) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl Alkyl methacrylates such as methacrylate. (4) acrylamide, methacrylamide, N-methylolacrylamide, N-ethylacrylamide, N-
Hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-
Acrylamide or methacrylamide such as phenylacrylamide, N-nitrophenylacrylamide, and N-ethyl-N-phenylacrylamide. (5) 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. (6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, and vinyl benzoate. (7) Styrenes such as styrene, α-methylstyrene, methylstyrene, and chloromethylstyrene. (8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone. (9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene. (10) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like. (11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, and N- (p-chlorobenzoyl) methacrylamide. (12) acrylic acid, methacrylic acid, maleic anhydride,
Unsaturated carboxylic acids such as itaconic acid;

In the present invention, as the alkali water-soluble polymer compound, those having a weight average molecular weight of 2,000 or more and a number average molecular weight of 500 or more, irrespective of a homopolymer or a copolymer, are preferable in view of film strength. 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 degree of dispersion (weight average molecular weight / number average molecular weight) is 1.1 to 10.

In the above copolymer, (b-1) to (b)
The compounding weight ratio of the monomer having an acidic group of (3) to another monomer is preferably in the range of 50:50 to 5:95 from the viewpoint of development latitude, and is preferably in the range of 40:60 to 10:90. Are more preferable.

These alkaline water-soluble polymer compounds include:
One type or a combination of two or more types may be used, and 30 to 99% by weight, preferably 40 to 95% by weight, and particularly preferably 50% by weight, based on the total solid content of the photosensitive composition.
It is used in an amount of up to 90% by weight. When the amount of the alkali-soluble polymer compound is less than 30% by weight, the durability of the recording layer is deteriorated.
It is not preferable in terms of durability.

[Other Components] The photosensitive composition of the present invention may further contain various additives, if necessary. For example, the use of a substance that is thermally decomposable, such as an aromatic sulfone compound or an aromatic sulfonic acid ester compound, and that substantially reduces the solubility of an alkali water-soluble polymer compound in a state where it is not decomposed can be used in the image area. It is preferable from the viewpoint of improving the dissolution inhibiting property in the developer.

For the purpose of further improving sensitivity, cyclic acid anhydrides, phenols and organic acids can be used in combination. As the cyclic acid anhydride, US Pat. No. 4,115,
No. 128, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,
6-endooxy-Δ ⁴ -tetrahydrophthalic anhydride,
Tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. Examples of phenols include bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone,
4 ', 4 "-trihydroxytriphenylmethane, 4,
4 ', 3 ", 4"-tetrahydroxy-3,5,3',
5'-tetramethyltriphenylmethane and the like. Further, as the organic acids, JP-A-60-88942
Sulfonic acids, sulfinic acids, alkyl sulfates, and the like described in JP-A-2-96755 and JP-A-2-96755.
Examples include phosphonic acids, phosphoric esters and carboxylic acids, and 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 cyclic acid anhydride, phenols and organic acids in the printing plate material is preferably 0.05 to 20% by weight, more preferably 0.1 to 15% by weight, and particularly preferably 0.1 to 15% by weight. 10% by weight.

In the printing plate material of the present invention,
Japanese Patent Application Laid-Open No.
Nonionic surfactants as described in JP-A-2-251740 and JP-A-3-208514, and amphoteric as described in JP-A-59-121044 and JP-A-4-13149. Surfactants can be added. Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, monoglyceride stearic acid, and polyoxyethylene nonyl phenyl ether. Specific examples of the surfactant include alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N
-Tetradecyl-N, N-betaine type (for example, trade name “Amogen K”: manufactured by Dai-ichi Kogyo Co., Ltd.) and the like. The proportion of the nonionic surfactant and the amphoteric surfactant in the printing plate material is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

In the printing plate material of the invention, a printing-out agent for obtaining a visible image immediately after heating by exposure, and a dye or pigment as an image coloring agent can be added. Representative examples of the printing-out agent include a combination of a compound that releases an acid by heating upon exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, combinations of o-naphthoquinonediazide-4-sulfonic acid halogenide and salt-forming organic dyes described in JP-A-50-36209 and JP-A-53-8128, No. 36223, No. 54-74728, No. 60
No.-3626, No.61-143748, No.61-15
Combinations of trihalomethyl compounds and salt-forming organic dyes described in JP-A Nos. 1644 and 63-58440 can be mentioned. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear print-out images.

As the colorant for the image, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. 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 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, crystal violet (CI42555), methyl Violet (CI42535), ethyl violet, rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5201)
5) and the like. Also, JP-A-62-2932
The dyes described in JP-B-47 are particularly preferred. These dyes are used in an amount of 0.01 to 10 based on the total solid content of the printing plate material.
% By weight, preferably 0.1 to 3% by weight, can be added to the printing plate material. Further, a plasticizer is added to the printing plate material of the present invention, if necessary, in order to impart flexibility and the like to the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate,
An oligomer or polymer of trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid, or the like is used.

Further, in addition to these, epoxy compounds, vinyl ethers, and JP-A-8-27655
Patent Document 8 discloses a phenol compound having a hydroxymethyl group, a phenol compound having an alkoxymethyl group and Japanese Patent Application No. 9-32837 filed by the present inventors.
A crosslinking agent having an alkali dissolution inhibiting action described in (1) can be appropriately added according to the purpose.

A lithographic printing plate precursor is prepared by dissolving a coating solution for a photosensitive layer containing the photosensitive composition of the present invention or a coating solution component for a desired layer such as a protective layer in a solvent and coating the solution on a suitable support. Can be manufactured. As the solvent used herein, 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 Ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyrolactone, toluene,
Water and the like can be mentioned, but it is not limited thereto. These solvents are used alone or as a mixture. The concentration of the above components (total solids including additives) in the solvent is preferably 1 to 50% by weight. The coating amount (solid content) on the support obtained after coating and drying varies depending on the application, but generally 0.5 to 5.0 g / m ² is preferred for a photosensitive printing plate. As a method of applying, various methods can be used, for example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating,
Roll coating and the like can be mentioned. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the photosensitive layer deteriorate.

In the photosensitive layer coating solution using the photosensitive composition of the present invention, a surfactant for improving the coating property,
For example, a fluorine-based surfactant as described in JP-A-62-170950 can be added.
The preferred addition amount is 0.01 to 1% by weight of the total printing plate material.
More preferably, it is 0.05 to 0.5% by weight.

The support used in the lithographic printing plate precursor according to the present invention is a dimensionally stable plate-like material.
Paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, butyric acid) Cellulose, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), a metal-laminated or vapor-deposited paper as described above,
Alternatively, a plastic film or the like is included.

The support used in the lithographic printing plate precursor according to the present invention is preferably a polyester film or an aluminum plate. Among them, an aluminum plate having good dimensional stability and relatively low cost is particularly preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and containing a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. Aluminum which is particularly preferred in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate used in the present invention is approximately 0.1 mm to 0.6 mm, preferably 0.15 m.
m to 0.4 mm, particularly preferably 0.2 mm to 0.3 m
m.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution is performed to remove rolling oil on the surface. The surface roughening treatment of the surface of the aluminum plate is performed by various methods, for example, a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. It is performed by the method of causing. As a mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can be used. The aluminum plate thus roughened is subjected to an alkali etching treatment and a neutralization treatment, if necessary, and then subjected to an anodic oxidation treatment, if desired, in order to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes for forming a porous oxide film can be used, and generally, 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 the electrolyte.

Since the anodizing treatment conditions vary depending on the electrolyte used, they cannot be specified unconditionally. Generally, however, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C., and the current density is 5 to 60 A. / Dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are appropriate. When the amount of the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image portion of the lithographic printing plate is easily scratched,
So-called "scratch stains" in which ink adheres to scratches during printing are likely to occur. After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment as necessary. U.S. Pat. Nos. 2,7,7
No. 14,066, No. 3,181,461, No. 3,2
There is an alkali metal silicate (e.g., sodium silicate aqueous solution) method as disclosed in U.S. Pat. Nos. 80,734 and 3,902,734. In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated. In addition, potassium fluoride zirconate disclosed in JP-B-36-22063 and U.S. Pat. Nos. 3,276,868 and 4,153,46.
For example, a method of treating with polyvinyl phosphonic acid as disclosed in JP-A Nos. 1 and 4,689,272 is used.

The lithographic printing plate precursor according to the invention has a positive photosensitive layer containing the photosensitive composition according to the invention provided on a support. If necessary, an undercoat layer may be provided between the layers. Can be. As the undercoat layer component, various organic compounds are used, for example, carboxymethyl cellulose, dextrin, gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, and phenylphosphonic acid optionally having a substituent , Naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, organic phosphonic acids such as methylenediphosphonic acid and ethylenediphosphonic acid, phenylphosphoric acid optionally having a substituent, naphthylphosphoric acid,
Organic phosphoric acids such as alkyl phosphoric acid and glycerophosphoric acid, organic phosphinic acids such as optionally substituted phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid, glycine and β
-Selected from amino acids such as alanine, and hydrochlorides of amines having a hydroxy group such as hydrochloride of triethanolamine, but may be used as a mixture of two or more.

The organic undercoat layer can be provided by the following method. That is, a method in which a solution obtained by dissolving the above organic compound in water or an organic solvent such as methanol, ethanol, or methyl ethyl ketone or a mixed solvent thereof is coated on an aluminum plate and dried, and a method in which water or methanol, ethanol, methyl ethyl ketone, or the like is used. A method in which an aluminum plate is immersed in a solution in which the above organic compound is dissolved in an organic solvent or a mixed solvent thereof to adsorb the above compound by immersing the aluminum plate, and then washed and dried with water or the like to provide an organic undercoat layer. . In the former method, a solution of the above organic compound having a concentration of 0.005 to 10% by weight can be applied by various methods. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, and 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 pH of the solution used for this is adjusted to pH 1 to 12 by a basic substance such as ammonia, triethylamine, potassium hydroxide, or an acidic substance such as hydrochloric acid or phosphoric acid.
It can also be adjusted to the range. Further, a yellow dye can be added for improving the tone reproducibility of the image recording material. The coating amount of the organic undercoat layer is suitably from ² to 200 mg / m ² , and preferably from 5 to 100 mg / m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same is true even if it is larger than 200 mg / m ² .

The positive-working lithographic printing plate precursor produced as described above is usually subjected to image exposure and development processing. Examples of the light source of the actinic ray used for the image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a carbon arc lamp, and the like. As radiation,
There are electron beams, X-rays, ion beams, far infrared rays, and the like. In addition, g-line, i-line, Deep-UV light, and high-density energy beam (laser beam) are also used. Examples of the laser beam include a helium / neon laser, an argon laser, a krypton laser, a helium / cadmium laser, a KrF excimer laser, a solid laser, and a semiconductor laser. In the present invention, a light source having an emission wavelength in the near infrared to infrared region is preferable, and a solid-state laser and a semiconductor laser are particularly preferable.

As the developer and replenisher for the lithographic printing plate precursor according to the invention, conventionally known alkaline aqueous solutions can be used. For example, sodium silicate, potassium, tribasic sodium, potassium, ammonium, dibasic sodium, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, potassium And inorganic alkali salts such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Further, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine,
Organic alkaline agents such as diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine, ethylenediamine and pyridine are also used.

These alkaline 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 silicon oxide SiO ₂ and alkali metal oxides are components of the silicate
This is because developability can be adjusted by the ratio and concentration of M ₂ O. For example, JP-A-54-62004 discloses
The alkali metal silicate described in JP-B-57-7427 is effectively used.

In the case of developing using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than the developing solution is used.
It has been known that a large amount of PS plates can be processed without replacing the developing solution in the developing tank for a long time by adding to the developing solution. This replenishment system is also preferably applied in the present invention. To the developing solution and the replenishing solution, various surfactants and organic solvents can be added as necessary for the purpose of promoting or suppressing the developing property, dispersing the developing residue and increasing the ink affinity of the printing plate image area. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Further, the developing solution and the replenisher may contain, if necessary, a reducing agent such as a sodium salt or a potassium salt of an inorganic acid such as hydroquinone, resorcinol, sulfurous acid, and bisulfite, and an organic carboxylic acid, an antifoaming agent, and a water softener. Can be added. The printing plate developed using the above developer and replenisher is post-treated with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. As a post-process when the image recording material of the present invention is used as a printing plate, these processes can be used in various combinations.

In recent years, in the plate making / printing industry, automatic developing machines for printing plates have been widely used in order to rationalize and standardize plate making operations. This automatic developing machine generally comprises a developing section and a post-processing section, and comprises a device for transporting a printing plate, each processing solution tank and a spray device, and while pumping the exposed printing plate horizontally, each pumped by a pump. The developing process is performed by spraying a processing liquid from a spray nozzle. Recently, a method has been known in which a printing plate is immersed and conveyed by a submerged guide roll or the like in a processing liquid tank filled with a processing liquid to perform processing. In such an automatic processing, the processing can be performed while replenishing each processing liquid with a replenisher according to the processing amount, the operating time, and the like. Further, a so-called disposable processing method in which processing is performed with a substantially unused processing liquid can also be applied.

The photosensitive lithographic printing plate precursor using the photosensitive composition of the present invention will be described. If the lithographic printing plate obtained by image exposure, development, washing and / or rinsing and / or gumming has unnecessary image portions (for example, film edge marks of the original film), unnecessary portions are unnecessary. Erasing of the image portion is performed. Such erasing is preferably performed by applying an erasing liquid as described in, for example, Japanese Patent Publication No. 2-129393 to an unnecessary image portion, leaving the same for a predetermined period of time, and then rinsing with water. A method described in JP-A-59-174842, in which active light guided by an optical fiber is applied to an unnecessary image portion and then developed, can be used.

The lithographic printing plate obtained as described above can be subjected to a printing step after applying a desensitized gum if desired. Is subjected to a burning process. When the lithographic printing plate is subjected to a burning process, before the burning process, Japanese Patent Publication Nos. 61-2518 and 55-28062,
It is preferable to treat with a surface-regulating liquid as described in JP-A Nos. 62-31859 and 61-159655. As a method, a sponge or absorbent cotton impregnated with the surface conditioning liquid is applied on a lithographic printing plate, or a method in which the printing plate is immersed in a vat filled with the surface conditioning solution and applied, Application by an automatic coater or the like is applied. Further, it is more preferable to make the application amount uniform with a squeegee or a squeegee roller after the application.

The coating amount of the surface conditioning liquid is generally 0.03 to 0.8.
g / m ² (dry weight) is appropriate. The lithographic printing plate to which the surface conditioning liquid has been applied is dried if necessary, and then burned (for example, a burning processor sold by Fuji Photo Film Co., Ltd .: "BP-130").
0 "). The heating temperature and time in this case depend on the type of the component forming the image,
The temperature is preferably in the range of 180 to 300 ° C. for 1 to 20 minutes.

The burned lithographic printing plate can be subjected to conventional treatments such as washing with water and gumming, if necessary. When a liquid is used, a so-called desensitizing treatment such as gumming can be omitted. The lithographic printing plate obtained by such a process is set on an offset printing machine or the like and used for printing a large number of sheets.

[0155]

EXAMPLES The present invention will be described below with reference to synthesis examples and examples of alkaline infrared absorbers, but the scope of the present invention is not limited to these synthesis examples and examples.

The synthesis of an alkaline infrared absorber useful in the present invention can be carried out by condensing a compound having active methylene and a methylene chain donor in the presence of a base as shown in the following scheme. This synthesis method is a general method for synthesizing a dye, for example, “Dyes and Chemicals” (1991).
Year) pp. 274 to 289, can be carried out according to the method for synthesizing oxonol dyes.

[0157]

Embedded image

Examples of the methylene chain donor include the following structures.

[0159]

Embedded image

(Synthesis Example 1: Synthesis of Compound A-1) Q-1
(0.1 mol), P-1 (0.1 mol), and methanol (500 ml) were placed in a beaker, and triethylamine (0.2 mol) was added dropwise over 10 minutes. It became a suspension. Tetrabutylammonium bromide (0.1 mol) was added to this solution, and the mixture was further stirred for 30 minutes to precipitate a dark blue solid. The precipitated solid was collected by filtration and washed with water to obtain A-1 in a yield of 55%. The structure of A-1 is represented by mass spectrometry, ¹ H-NM
R, confirmed by infrared absorption spectrum.

[0161]

Embedded image

(Synthesis Example 2: Synthesis of Compound A-2) Compound A-1 (0.1 mol) and methanol (500 ml) were placed in a beaker, and the diazonium salt P-2 (0.5 mol) was added.
The aqueous solution of 1) was added, and the mixture was stirred at room temperature for 30 minutes to precipitate a dark blue solid. This solid was collected by filtration, placed again in a beaker with methanol (500 ml), and an aqueous solution of diazonium salt P-2 (0.5 mol) was added.
Stirred for minutes. The precipitated solid was collected by filtration and washed well with water to obtain A-2 at a yield of 90%. The structure of A-2 was confirmed by mass spectrometry, ¹ H-NMR, and infrared absorption spectrum.

[0163]

Embedded image

(Synthesis Example 3: Synthesis of Compound A-3) Compound A-1 (0.1 mol) and methanol (500 ml) were placed in a beaker, and an iodonium salt P-3 (0.5 mol) was added.
The aqueous solution of 1) was added, and the mixture was stirred at room temperature for 30 minutes to precipitate a dark blue solid. This solid was collected by filtration, placed again in a beaker with methanol (500 ml), and an aqueous solution of iodonium salt P-3 (0.5 mol) was added.
Stirred for minutes. The precipitated solid was collected by filtration and washed well with water to obtain A-3 at a yield of 88%. The structure of A-3 was confirmed by mass spectrometry, ¹ H-NMR, and infrared absorption spectrum.

[0165]

Embedded image

Similarly, A-4 to A-16 can be synthesized.

(Examples 1 to 18) [Preparation of substrate] An aluminum plate having a thickness of 0.3 mm (material
1050) was degreased by washing with trichloroethylene.
After, nylon brush and 400 mesh pumice-water suspension
The surface was grained using a liquid and washed well with water. This
Plate for 9 seconds in a 25% aqueous solution of sodium hydroxide at 45 ° C
Etching by immersion, washing with water, and then 20% nitric acid
For 20 seconds and washed with water. At this time,
Etching amount is about 3g / m ^TwoMet. Next, this plate
% Sulfuric acid as electrolyte and current density 15A / dm^Two3g /
m^TwoAfter providing a direct current anodic oxide coating of
Furthermore, the following undercoat liquid is applied, and the coating film is dried at 90 ° C. for 1 minute.
Dried. The coating amount of the dried coating film is 10 mg / m^TwoSo
Was.

<Composition of Undercoat Liquid> 0.5 g of β-alanine 95 g of methanol 5 g of water

On the obtained substrate, the following photosensitive solution 1 was prepared by changing the infrared absorbing agent as shown in Table 1 below, and each was applied so that the coating amount became 1.8 g / m ^2. 1 to 18 planographic printing plate precursors were obtained.

<Composition of Photosensitive Liquid 1> m, p-cresol novolak (m / p ratio = 6/4, weight average molecular weight 3500, unreacted cresol 0.5% by weight) 1.0 g * alkaline water Soluble polymer compound ・ Infrared absorber described in Table 1 0.2 g * Compound represented by general formula (I) ・ Dye in which the counter anion of Victoria Pure Blue BOH is changed to 1-naphthalenesulfonic acid anion 0.02 g ・Fluorosurfactant (MegaFac F-177, manufactured by Dainippon Ink and Chemicals, Inc.) 0.05 g • γ-butyrolactone 3 g • Methyl ethyl ketone 8 g • 1-methoxy-2-propanol 7 g

(Examples 19 to 36) [Synthesis of Copolymer as Alkaline Aqueous Solution-Soluble Polymer Compound] <Synthesis Example (Copolymer 1)> Methacryl was placed in a 500 ml three-necked flask equipped with a stirrer, a cooling tube and a dropping funnel. Acid 3
1.0 g (0.36 mol), ethyl chloroformate 39.1
g (0.36 mol) and 200 ml of acetonitrile were added, and the mixture was stirred while cooling in an ice-water bath. To this mixture, 36.4 g (0.36 mol) of triethylamine was dropped by a dropping funnel over about 1 hour. After dropping,
The ice water bath was removed and the mixture was stirred at room temperature for 30 minutes.

To the reaction mixture was added 51.7 g (0.30 mol) of p-aminobenzenesulfonamide, and the mixture was stirred for 1 hour while warming to 70 ° C. in an oil bath. After completion of the reaction, the mixture was added to 1 liter of water while stirring the water, and the resulting mixture was stirred for 30 minutes. The mixture was filtered to remove the precipitate, which was then washed with 500 m of water.
Then, the slurry was filtered and the obtained solid was dried to obtain a white solid of N- (p-aminosulfonylphenyl) methacrylamide (yield 46.9 g).

Next, 5.04 g of N- (p-aminosulfonylphenyl) methacrylamide was placed in a 100 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel.
210 mol), and 2.05 g (0.05 g) of ethyl methacrylate.
180 mol), acrylonitrile 1.11 g (0.02
1 mol) and 20 g of N, N-dimethylacetamide, and the mixture was stirred while being heated to 65 ° C. in a hot water bath. This mixture was mixed with “V-65” (manufactured by Wako Pure Chemical Industries, Ltd.).
0.15 g was added, and the mixture was stirred for 2 hours under a nitrogen stream while maintaining at 65 ° C. N- (p-
Aminosulfonylphenyl) methacrylamide 5.04
g, 2.05 g of ethyl methacrylate, 1.11 g of acrylonitrile, 20 g of N, N-dimethylacetamide, and 0.15 g of "V-65" were dropped by a dropping funnel over 2 hours. After the addition was completed, the resulting mixture was further stirred at 65 ° C. for 2 hours. After completion of the reaction, methanol 40
g was added to the mixture, the mixture was cooled, and the obtained mixture was poured into 2 liters of water while stirring the water. After stirring the mixture for 30 minutes, the precipitate was taken out by filtration and dried to obtain 15 g of a white solid. I got The weight average molecular weight of this copolymer 1 (polystyrene standard) was measured by gel permeation chromatography and found to be 53,000.
It was 0.

In the same manner as the substrates used in Examples 1 to 18, the following photosensitive solution 2 was prepared by changing the infrared absorbing agent as shown in Table 2 below, and the coating amount of each was 1.8.
g / m ² to obtain lithographic printing plate precursors of Examples 19 to 36. <Composition of Photosensitive Liquid 2> • 1 g of the above copolymer • 0.1 g of the infrared absorber in Table 2 * Compound represented by the general formula (I) • 0.002 g of p-toluenesulfonic acid • Victoria Dye in which the counter anion of pure blue BOH is changed to 1-naphthalenesulfonic acid anion 0.02 g ・ Fluorine-based surfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0.05 g ・ γ -Butyrolactone 8 g, methyl ethyl ketone 8 g, 1-methoxy-2-propanol 4 g

(Comparative Examples 1 to 3) In Example 1, the infrared absorber represented by the following structure was replaced by the infrared absorbers B-1, B-2, B-3
The lithographic printing plate precursors of Comparative Examples 1 to 3 were obtained in exactly the same manner as in Example 1 except that the lithographic printing plate precursor was replaced.

[0176]

Embedded image

(Comparative Examples 4 to 6) In Example 19, the infrared absorbing agents represented by the general formula (I) blended in the photosensitive solution 2 were replaced by the infrared absorbing agents B-1 and B-2 represented by the above structure. , B
Except for changing to -3, lithographic printing plate precursors of Comparative Examples 4 to 6 were obtained in exactly the same manner as in Example 19.

[Evaluation of Performance of Lithographic Printing Plate Precursor] The lithographic printing plate precursors of Examples 1 to 36 and Comparative Examples 1 to 6 produced as described above were evaluated for performance according to the following criteria. The evaluation results are shown in Tables 1 and 2.

(Evaluation of Image Formability: Sensitivity and Development Latitude) The obtained lithographic printing plate precursor was exposed using a semiconductor laser having a wavelength of 840 nm, and a developing solution DP-4 and a rinsing solution manufactured by Fuji Photo Film Co., Ltd. FR-3 (1: 7)
Automatic developing machine (Fuji Photo Film Co., Ltd.):
"PS processor 900VR").
At that time, DP-4 was diluted 1: 6 and 1:12.
The line width of the non-image area obtained with each developing solution was measured using two levels of those diluted with, and the irradiation energy of the laser corresponding to the line width was determined, and this was used as the sensitivity. Then, a standard 1: 6 dilution and a 1: 6 dilution were used.
The difference from the one diluted at 12 was recorded. The smaller the difference, the better the development latitude, and 20 mJ / cm ²
Below is a practical level.

(Evaluation of Storage Stability) The obtained lithographic printing plate precursor was stored at 60 ° C. for 3 days before laser exposure.
Thereafter, laser exposure and development were performed in the same manner as described above, and the sensitivity was measured in the same manner and compared with the above results. If the variation in sensitivity is 20 mJ / cm ² or less, the storage stability is good and is at a practical level.

[0181]

[Table 1]

[0182]

[Table 2]

From the results shown in Tables 1 and 2, Examples 1 to 36 were obtained.
It was found that the lithographic printing plate precursors of Comparative Examples 1 to 6 had higher sensitivity to the infrared laser than the lithographic printing plate precursors of Comparative Examples 1 to 6. In addition, the difference in sensitivity between the two dilution concentrations of the developer is extremely small, and 20 mJ /
has achieved cm ² or less performance, it was confirmed to have excellent development latitude. Furthermore, from the results of the evaluation of storage stability, all of the lithographic printing plate precursors of the present invention require a fluctuation of sensitivity before and after storage of 20 mJ, which is practically required.
/ Cm ² or less.

[0184]

According to the present invention, it is possible to provide a photosensitive composition having high sensitivity and excellent stability in sensitivity to the concentration of a developer, that is, excellent development latitude and storage stability. In addition, lithographic printing plate precursors using this photosensitive composition can be directly made by infrared laser, and have high sensitivity,
In addition, there is an excellent effect that development latitude and storage stability are good.

Claims (4)

[Claims] 1. A photosensitive composition comprising the following (a) and (b) and being soluble in an alkaline aqueous solution by irradiation with an infrared laser. (A) an anionic infrared absorber; (b) a polymer compound that is insoluble in water and soluble in an aqueous alkaline solution. 2. The (a) anionic infrared absorbent comprises:
(A-1) an anionic metal complex, (a-2) anionic carbon black, (a-3) anionic phthalocyanine, or (a-4) a compound represented by the following general formula (I). The photosensitive composition according to claim 1, characterized in that: Embedded image Wherein, M represents a conjugated chain, G _a ^- represents an anionic substituent, G _b represents a neutral substituent. X ^{m +} represents a 1- to m-valent cation containing a proton, where m represents an integer of 1 to 6. 3. The photosensitive composition according to claim 1, wherein the counter cation of the (a) anionic infrared absorber has a thermally decomposable onium salt structure. 4. A lithographic printing plate precursor comprising a support and a photosensitive layer comprising the photosensitive composition according to claim 1 provided on a support.