JP2001174980A - Photosensitive composition and original plate of planographic printing plate using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive composition having high sensitivity, good development latitude and good preservation stability and a positive type original plate of a planographic printing plate using the composition and capable of forming an image with an IR laser for direct plate making with high sensitivity. SOLUTION: The photosensitive composition contains (a) an IR absorber of formula I (where R1 and R2 are each a 1-18C alkyl or a 9-30C aryl; and Z is heptamethine which may have a substituent) and (b) a high molecular compound insoluble in water and soluble in an aqueous alkali solution. The composition is made soluble in the aqueous alkali solution when irradiated with an IR laser.

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 a light emitting region from near infrared to infrared, as a system for making a plate directly 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 formed in an image area. However, it acts as a dissolution inhibitor that substantially lowers the solubility of the alkali aqueous solution-soluble resin, and is decomposed by heat in the non-image area to exhibit no dissolution inhibiting ability, so that it can be removed by development, and the image can be removed. Form.

As a result of the study by the present inventors, it has been found that a positive image can be obtained without adding a quinonediazide compound to the 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 image forming material for infrared laser, 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 the infrared absorbing dye absorbs the laser beam and the generated heat causes the effect of suppressing the dissolution of the polymer film at the irradiated portion to disappear, thereby forming an image. Although the image-forming property is sufficient on the laser-irradiated surface of the light-sensitive material, the effect is not sufficient 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 development 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 wide developing latitude, excellent image forming properties, and
Provided is a photosensitive composition having good storage stability without deteriorating its image formability even after long-term storage, and a positive lithographic printing plate precursor using the same, which can form an image with an infrared laser for direct plate making. It is.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies for the purpose of increasing image forming properties, that is, developing latitude, and improving storage stability. As a result, it was found that both the development latitude and the storage stability were improved, and the present invention was completed.

That is, the photosensitive composition of the present invention comprises (a) an infrared absorbing agent represented by the following general formula (I), and (b) a high-soluble infrared-absorbing agent which is insoluble in water and soluble in an aqueous alkali solution. It contains a molecular compound, and is characterized in that its solubility in an alkaline aqueous solution is changed by irradiation with an infrared laser.

[0008]

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Where X¹, X^TwoIs each independently -CR
⁷R⁸-, -S-, -Se-, -NR ⁹-, -CH = CH
Represents-or -O-. R¹And R^TwoAre independent
Represents an alkyl group having 9 to 30 carbon atoms;^Three,
R^Four, R^FiveAnd R⁶Are each independently a hydrogen atom, carbon
The atom represents an alkyl group of 1 to 10;^ThreeAnd R^FourOr R
^FiveAnd R⁶Are bonded to each other to form an aliphatic 5- or 6-membered ring,
Aromatic 6-membered ring, aromatic 10-membered ring, substituted aromatic 6-membered ring or
Lists the multiple atoms required to form a substituted aromatic 10-membered ring.
May be. R⁷, R⁸Each independently has 1 carbon atom
To 18 alkyl groups and aryl groups having 6 to 18 carbon atoms
And R⁹Is an alkyl group having 1 to 18 carbon atoms,
Elementary atoms represent 6 to 18 aryl groups. Z has a substituent
Represents a heptamethine group, which may be substituted
Alkyl group, halogen atom, amino group with 8 or less elementary atoms
Or the heptamethine group is the two
The substituents formed by the substituents on the carbon
Cyclohexene ring or cyclopentene which may be possessed
It may contain a ring, and the substituent on this ring structure is
Select from alkyl groups having 6 or less carbon atoms or halogen atoms
Selected. Q represents a counter ion.

In a preferred embodiment, the counter ion Q of the infrared absorbent represented by the general formula (I) is represented by the following general formula (II) or a counter ion having a sulfonic acid structure. .

[0011]

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In the formula, A represents an atom selected from the group consisting of B, P, As, Sb, Cl and Br, and Y represents a halogen atom or an oxygen atom. m represents an integer of 1 to 6.

Although the function of the present invention is not clear, (a) by introducing a long-chain alkyl group at the N-position of the dye in the infrared absorbing agent represented by the general formula (I), the organic property of the dye is improved. In addition, efficient photothermal conversion is performed on the surface of the photosensitive layer, and further, the stability is improved by the presence of an infrared absorber having a long-chain alkyl group. The affinity and (b) the ability to inhibit the dissolution of an alkali water-soluble polymer are improved. For this reason,
Improvement of image formability and suppression of deterioration of image formability after long-term storage can be achieved. The lithographic printing plate precursor according to the present invention according to claim 4 is characterized in that a photosensitive layer comprising the above-described photosensitive composition is provided on a support.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [(A) Infrared absorbent represented by the general formula (I)] The infrared absorbent represented by the general formula (I) is a polymer that is unnecessary in water and soluble in alkaline water. Interaction with the compound can greatly reduce the solubility of the image area in an alkali developer. In the non-image area, alkali solubility is restored by decomposing the infrared absorbent itself represented by the general formula (I) and / or canceling the interaction caused by heat generation due to absorption of near infrared rays. Good discrimination in formation develops.

The infrared absorbent represented by the above formula (I) will be described in more detail. In the formula (I), the X ^1, X ² are each ^{independently, -CR 7 R 8 -, -} S -, - Se -, - NR
⁹ -, - shows a CH = CH- or -O-. here,
R ⁷ and R ^{8 each} represent an alkyl group having 1 to 18 carbon atoms, a substituted alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a substituted aryl group having 6 to 18 carbon atoms. . R ¹ and R ² each independently have 9 to 3 carbon atoms.
Represents an alkyl group of 0, and these alkyl groups may have a substituent.

[0016] R ^3, R ^4, R ^5, and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a substituted alkyl of 1 to 10 carbon atoms, R ³ and R ⁴ Or R ⁵ and R ⁶ are combined to form an aliphatic 5- or 6-membered ring, an aromatic 6-membered ring, an aromatic 10-membered ring, a substituted aromatic 6-membered ring or a substituted aromatic 10-membered ring. R ⁹ may represent an alkyl group having 1 to 18 carbon atoms, a substituted alkyl group having 1 to 18 carbon atoms, and 6 to 1 carbon atoms.
8 represents a substituted aryl group having 6 to 18 carbon atoms.

The alkyl group represented by R ^{1 to} R ⁹ has 9 to 30 carbon atoms, or 1 to 1 carbon atoms.
Up to 8 linear, branched, or cyclic alkyl groups are included. Specifically, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,
Octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s
-Butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group, and 2-norbornyl group. Among these, R ¹ and R ² are linear alkyl groups, and R ^{3 to} R ⁹ are those having 1 to 1 carbon atoms.
Linear to 0, branched from 3 to 12 carbon atoms,
Further, a cyclic alkyl group having 5 to 10 carbon atoms is more preferable.

When these alkyl groups have a substituent, a monovalent nonmetallic atomic group other than hydrogen is used as the substituent. Preferred examples include a halogen atom (-
F, -Br, -C1, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N -Dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, An N, N-dialkylcarbamoyloxy group,
N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, A ureido group, an N′-alkylureido group, an N ′, N′-dialkylureido group, an N′-arylureido group, an N ′, N′-diarylureido group,
N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido group, N'-alkyl-N-
Arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N'-aryl-N- Arylureido group,
An N ′, N′-diaryl-N-alkylureido group,
An N ′, N′-diaryl-N-arylureido group,
N'-alkyl-N'-aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxy Carbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group, and the like A conjugate base group (hereinafter referred to as “carboxylate”), an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an N-alkylcarbamoyl group, an N, N-dialkylcarbamoyl group, an N-arylcarbamoyl group, N, N- Diarylcarbamoyl group, N-alkyl-N - (. Hereinafter referred to as "sulfonato group") arylcarbamoyl group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugate base, alkoxysulfonyl group, an aryloxy A sulfonyl group, a sulfinamoyl group, an N-alkylsulfinamoyl group, an N, N-dialkylsulfinamoyl group,

N-arylsulfinamoyl group, N, N
-Diarylsulfinamoyl group, N-alkyl-N-
Arylsulfinamoyl group, sulfamoyl group, N-
Alkylsulfamoyl group, N, N-dialkylsulfur
Amoyl group, N-arylsulfamoyl group, N, N-
Diarylsulfamoyl group, N-alkyl-N-ali
Sulfamoyl group, N-acylsulfamoyl group and
And its conjugate base group, N-alkylsulfonylsulfamo
Il group (-SO_TwoNHSO_TwoR and R represent an alkyl group
You. ) And its conjugated base group, N-arylsulfonyls
Rufamoyl group (-SO_TwoNHSO_TwoAr, Ar is ant
Represents a hydroxyl group. ) And its conjugated base group, N-alkyls
Ruphonylcarbamoyl group (-CONHSO_TwoR, R is a
Represents a alkyl group. ) And its conjugated base group, N-aryl
Sulfonylcarbamoyl group (-CONHSO_TwoAr, A
r represents an aryl group. ) And its conjugated base group, alcohol
Xysilyl group (-Si (OR)_Three, R represents an alkyl group
You. ), Aryloxysilyl group (—Si (OAr)_Three,
Ar represents an aryl group. ), Hydroxysilyl group (-
Si (OH)_Three) And its conjugate base group, phosphono group (one
PO_ThreeH_Two) And its conjugated base group (hereinafter referred to as “phosphonato
Base. " ), A dialkylphosphono group (—PO
_ThreeR_Two, R represents an alkyl group. ), Diarylphospho
No group (-PO_ThreeAr_Two, Ar represents an aryl group. ),
Alkylarylphosphono group (-PO_Three(R) (A
r) and R represent an alkyl group and Ar represents an aryl group. )
Noalkylphosphono group (-PO_ThreeH (R), R is alk
Represents a hydroxyl group. ) And its conjugated base group (hereinafter referred to as “alkyl
"Phosphonato group". ), Monoarylphosphono group
(-PO_ThreeH (Ar) and Ar represent an aryl group. )
And its conjugate base group (hereinafter referred to as “arylphosphonate group”)
Say. ), A phosphonooxy group (—OPO)_ThreeH_Two) And that
Conjugated base group (hereinafter referred to as "phosphonatooxy group")
U. ), A dialkylphosphonooxy group (—OPO
_Three(R)_Two, R represents an alkyl group. ), Diarylho
Suphonoxy group (-OPO_Three(Ar)_Two, Ar is ally
Represents a hydroxyl group. ), Alkylarylphosphonooxy group
(-OPO_Three(R) (Ar), R is an alkyl group, Ar is
Represents an aryl group. ), Monoalkylphosphonooxy group
(-OPO_ThreeH (R) and R represent an alkyl group. )as well as
The conjugate base group (hereinafter referred to as “alkylphosphonatooxy
Base. " ), Monoarylphosphonooxy group (—O
PO_ThreeH (Ar) Ar represents an aryl group. ) And that
Conjugated base group (hereinafter referred to as “arylphosphonatooxy group”)
That. ), Cyano group, nitro group, aryl group, alk
And an alkynyl group.

Specific examples of the alkyl group in these substituents to be substituted for the alkyl group include the above-mentioned alkyl groups. Specific examples of the aryl group include phenyl, biphenyl, naphthyl and tolyl. Group, xylyl group, mesityl group, cumenyl group, fluorophenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxy Phenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group,
Examples include a phenoxycarbonylphenyl group, an N-phenylcarbamoylphenyl group, a phenyl group, a nitrophenyl group, a cyanophenyl group, a sulfophenyl group, a sulfonatophenyl group, a phosphonophenyl group, and a phosphonatophenyl group. Examples of the aryl group as a substituent for the alkyl group include the above-mentioned aryl groups. Examples of the alkenyl group include a vinyl group, a 1-propenyl group, a 1-butenyl group and a cinnamyl group. Group, 2-chloro-1-ethenyl group, and the like. Further, examples of the alkynyl group include an ethynyl group,
-Propynyl group, 1-butynyl group, trimethylsilylethynyl group, phenylethynyl group and the like.

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, alkylphosphonate group, monoarylphosphono group, arylphosphonato group, phosphonooxy group , A phosphonatoxy group, an aryl group, an alkenyl group and the like.

On the other hand, in the substituted alkyl group, the alkylene group constituting the substituted alkyl group in combination with the substituent is the same as the alkylene group having 1 to 30 carbon atoms except for any one of the hydrogen atoms on the alkyl group. And R ^{3 to} R ⁹ are preferably a linear group having 1 to 12 carbon atoms, a branched group having 3 to 12 carbon atoms, and a bivalent organic residue. 5 carbon atoms
To 10 cyclic alkylene groups. Preferred specific examples of the substituted alkyl group obtained by combining the substituent and an alkylene group include a chloromethyl group, a bromomethyl group, a 2-chloroethyl group,
Trifluoromethyl group, methoxymethyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, Benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxy Carbonylethyl group, methoxycarbonylmethyl group, methoxycarbonylbutyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylca Bamoiruechiru group, N, N-dipropyl galvanometer carbamoylmethyl group, N- (methoxyphenyl)
Galvamoylethyl group, N-methyl-N- (sulfophenyl) galvamoylmethyl group, sulfopropyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipro Pyrsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-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.

The aryl group represented by R ^{1 to} R ¹⁰ may be a group in which one to three benzene rings form a condensed ring, or a group in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. Specific examples thereof include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenabutenyl group, and a fluorenyl group. Of these, a phenyl group and a naphthyl group are more preferable.

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 substituted aryl groups include biphenyl, tolyl, xylyl, mesityl, cumenyl, chlorophenyl, bromophenyl, fluorophenyl, chloromethylphenyl, and trifluoromethylphenyl. , Hydroxyphenyl, methoxyphenyl, methoxyethoxyphenyl, allyloxyphenyl, phenoxyphenyl, methylthiophenyl, tolylthiophenyl, phenylthiophenyl, ethylaminophenyl, dimethylaminophenyl, diethylaminophenyl , Morpholinophenyl group, acetyloxyphenyl group, benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group, acetylaminophen Le group, N- methyl-benzoylamino phenyl group, carboxyphenyl group,
Methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, galbamoylphenyl group, N-methylgalbamoylphenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) galbamoylphenyl group N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, N-
A methyl-N- (phosphonophenyl) sulfamoylphenyl group, a phosphonophenyl group, a phosphonatophenyl group,
Diethylphosphonophenyl group, diphenylphosphonophenyl group, methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonatophenyl group, allylphenyl group, 1-propenylmethylphenyl group, 2-butyl A phenylphenyl group, a 2-methylallylphenyl group, a 2-methylpropenylphenyl group,
2-propynylphenyl group, 2-butynylphenyl group,
And a 3-butynylphenyl group.

Z represents a heptamethine group which may have a substituent. When the heptamethine group has a substituent, examples of the substituent include an alkyl group having 8 or less carbon atoms, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group,
Examples include an arylthio group, an N-alkylamino group, an N, N-dialkylamino group, an N-arylamino group, an N, N-diarylamino group, a heterocyclic group, and the like. ^It may be substituted by the same substituents as ^{1 to} R ⁶ have. Among them, heptamethine group having no substituent, heptamethine group having a halogen atom as a substituent, heptamethine group having an arylthio group as a substituent, As N,
A heptamethine group having an N-diarylamino group is preferred. In addition, the heptamethine group may include a cyclohexene ring or a cyclopentene ring formed by bonding the substituents on the two methine carbons to each other. One or more such ring structures may be present in heptamethine. Incidentally, these ring structures may have a substituent, as a substituent on this ring structure,
Examples thereof include an alkyl group having 6 or less carbon atoms or a halogen atom. Among these, from the viewpoint of ease of synthesis,
An alkyl group having 6 or less carbon atoms is preferred.

Q represents a counter ion, but may form a bond with R ^{1 to} R ⁶ to form an inner salt. The counter ion Q is not particularly limited, and any known counter ion of the infrared absorbing dye can be arbitrarily applied as long as it matches the absorption wavelength range of the infrared absorbing agent. As the counter ion, those represented by the above general formula (II) are preferable, wherein A is B, P, As, Sb, Cl and Br.
Represents an atom selected from the group consisting of: B, P, Sb, and Cl are preferred from the viewpoint of ease of synthesis and safety of the compound. Y is a halogen atom, for example, Cl, I, Br, F
Or an oxygen atom. Among them, Y is preferably a fluorine or oxygen atom from the viewpoint of availability of raw materials. m represents an integer of 1 to 6, and preferably ranges from 4 to 6. Preferred counter ions Q in the present invention are listed below, but are not limited thereto.

[0028]

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As Q, those having a sulfonic acid structure in the structure are also preferably used. Examples of the counter anion having a sulfonic acid structure that can be used as the counter ion Q in the infrared absorbent of the present invention include the following. 1) methanesulfonic acid ion, 2) ethanesulfonic acid ion, 3) 1-propanesulfonic acid ion, 4) 2-propanesulfonic acid ion, 5) n-butanesulfonic acid ion, 6) allylsulfonic acid ion, 7) 10) camphorsulfonic acid ion, 8) trifluoromethanesulfonic acid ion, 9) pentafluoroethanesulfonic acid ion, 10) benzenesulfonic acid ion, 11) p-toluenesulfonic acid ion, 12) 3-methoxybenzenesulfonic acid ion, 13) 4-methoxybenzenesulfonic acid ion, 14) 4-hydroxybenzenesulfonic acid ion, 15) 4-chlorobenzenesulfonic acid ion, 16) 3-nitrobenzenesulfonic acid ion, 17) 4-nitrobenzenesulfonic acid ion,

18) 4-acetylbenzenesulfonate ion, 19) pentafluorobenzenesulfonate ion, 20) 4-dodecylbenzenesulfonate ion, 21) mesitylenesulfonate ion, 22) 2,4,6-triisopropylbenzene Sulfonate ion, 23) 2-hydroxy-4-methoxybenzophenone-
5-sulfonic acid ion, 24) dimethyl isophthalate-5-sulfonic acid ion, 25) diphenylamine-4-sulfonic acid ion, 26) 1-naphthalenesulfonic acid ion, 27) 2-naphthalenesulfonic acid ion, 28) 2- Naphthol-6-sulfonic acid ion, 29) 2-naphthol-7-sulfonic acid ion, 30) anthraquinone-1-sulfonic acid ion, 31) anthraquinone-2-sulfonic acid ion, 32) 9,10-dimethoxyanthracene-2 33) 9,10-diethoxyanthracene-2-sulfonate ion, 34) quinoline-8-sulfonate ion, 35) 8-hydroxyquinoline-5-sulfonate ion, 36) 8-anilino- Naphthalene-1-sulfonic acid ion.

Next, a method for producing the infrared absorbent represented by the above general formula (I) will be described. Formula (I)
Can be produced by a known organic synthesis technique. Specific synthesis methods are described in U.S. Pat. No. 5,441,866, Zh. Org. Khim. Twenty-eighth
Volume (No. 10), 1992, pp. 2159-2164,
The method described in EP 464,543 A1 can be mentioned.

The specific examples of the infrared absorbing agent represented by the above general formula (I) [(IR-1) to (IR-30)] are shown below. It is not limited.

[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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In the present invention, these infrared absorbers are used in an amount of 0.01 to 50% by weight, preferably 0.1 to 20% by weight, more preferably 0.5 to 0.5% by weight based on the total solid content of the photosensitive composition. -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.

In 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 pigments include commercially available pigments and color index (CI) handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, 1977), “Latest Pigment Application Technology” (C
MC Publishing, 1986), "Printing ink technology" CMC
Published in 1984) can be used.

The 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 dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, cyanine dyes, diimonium dyes, and aminium 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 squarylium dyes described in British Patent No. 434,875, and dihydroperimidine squarylium dyes described in US Pat. No. 5,380,635.

As a dye, US Pat.
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645 (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 pyrylium compounds disclosed in Japanese Examined Patent Publication Nos. 5-135514 and 5-19702, and as commercially available products, Epollight III-178, Epollight
III-130, Epollight III-125, Epo
Light IV-62A (Eporin) 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 when 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 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, 2- (4-hydroxyphenyl) ethyl methacrylate, 2- (N '- (4
-Hydroxyphenyl) ureido) ethyl acrylate, 2- (N '-(4-hydroxyphenyl) ureido) ethyl methacrylate and the like can be suitably used.

The weight average molecular weight of the polymer is 5.0 × 10 ²
2.0 × 10 ⁵ , and the number average molecular weight is 2.0 × 10 ²
Those having a density of 1.0 × 10 ⁵ are preferred in view of image forming properties.
These resins may be used alone or in combination of two or more. 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.

Further, as described in US Pat. No. 4,123,279, phenol having a C3-8 alkyl group as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, and formaldehyde are used. May be used in combination. These resins having a phenolic hydroxyl group may be used alone or in combination of two or more.

In the case of (b-2) an alkaline water-soluble polymer compound having a sulfonamide group, the main monomer constituting the polymer compound is (b-2) a monomer having a sulfonamide group in one molecule. Examples of the monomer include a low molecular weight compound having a sulfonamide group having at least one hydrogen atom 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 a compound include compounds represented by the following general formulas (3) to (7).

[0056]

Embedded image

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}, R¹⁷, R³³Are hydrogen atoms, respectively
C1-C12 alkyl which may have a substituent
Group, cycloalkyl group, aryl group or aralkyl group
Show. Also, R²⁶, R³⁷Has 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-.

Specifically, m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be preferably 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 an active imino group represented by the following formula and a low molecular compound having at least one polymerizable unsaturated bond in one molecule Is mentioned.

[0060]

Embedded image

As such a compound, specifically,
N- (p-toluenesulfonyl) methacrylamide, N
-(P-Toluenesulfonyl) acrylamide and the like can be suitably used.

In the alkaline 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 kinds of monomers or two or more kinds of monomers having different acidic groups can also be used. As the 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 when a copolymer component is used, 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 and methacrylic esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate. (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, N- (p-chlorobenzoyl) methacrylamide. (12) acrylic acid, methacrylic acid, maleic anhydride,
Unsaturated carboxylic acids such as itaconic acid;

In the present invention, the alkali water-soluble polymer compound 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, is preferable from the viewpoint 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.

Examples of preferred high molecular compounds having a phenolic hydroxyl group in the present invention include novolak resins such as a condensation polymer of m- / p-mixed cresol and formaldehyde, a condensation polymer of phenol, cresol and formaldehyde, and the like. Copolymers of (4-hydroxyphenyl) methacrylamide / methyl methacrylate / acrylonitrile, copolymers of 2- (N ′-(4-hydroxyphenyl) ureido) ethyl methacrylate / methyl methacrylate / acrylonitrile, and the like can be given. In the present invention, a preferable polymer compound having a sulfonamide group includes a copolymer of N- (p-aminosulfonylphenyl) methacrylamide / methyl methacrylate / acrylonitrile, and the like. Is N- (p-toluenesulfonyl) methacrylamide / methyl methacrylate / acrylonitrile / 2-
Examples include a copolymer of hydroxyethyl methacrylate.

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] Various additives can be further added to the photosensitive composition of the present invention, if necessary. For example, it is preferable to add another onium salt, an aromatic sulfone compound, an aromatic sulfonate compound, a polyfunctional amine compound, or the like, because the function of inhibiting the dissolution of the alkali water-soluble polymer in the developer can be improved.

Examples of the onium salts include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts and the like. Suitable onium salts for use in the present invention include, for example, S.I. I.
Schlesinger, Photogr. Sci. E
ng. , 18, 387 (1974); S. Bal
et al, Polymer, 21, 423 (198
0) or diazonium salts described in JP-A-5-158230, U.S. Pat. Nos. 4,069,055 and 4,069,056, or JP-A-3-140140.
Ammonium salts described in JP-A No. C. Necker
et al, Macromolecules, 17,
2468 (1984), C.I. S. Wen et al,
Teh, Proc. Conf. Rad. Curing
ASIA, p478 Tokyo, Oct (1988),
US Patent No. 4,069,055 or 4,06
The phosphonium salt described in No. 9,056,

J. V. Crivello et al,
Macromolecules, 10 (6), 1307
(1977), Chem. & Eng. News, No
v. 28, p31 (1988), EP 104,1
No. 43, U.S. Pat. Nos. 339,049 and 410,2
No. 01, JP-A-2-150848 or JP-A-2-296514;
V. Crivello et al, Polymer
J. 17, 73 (1985); V. Crivell
o et al. J. Org. Chem. , 43,30
55 (1978); R. Watt et al,
J. Polymer Sci. , Polymer Ch
em. Ed. , 22, 1789 (1984); V.
Crivello et al, Polymer Bu
ll. , 14, 279 (1985); V. Criv
ello et al, Macromorecule
s, 14 (5), 1141 (1981); V. Cr
ivello et al, J. Mol. Polymer Sc
i. , Polymer Chem. Ed. , 17,287
7 (1979), European Patent Nos. 370,693 and 23
No. 3,567, No. 297,443, No. 297,442
No. 4,933,377 and 3,902,
No. 114, No. 410, 201, No. 339, 049,
No. 4,760,013, No. 4,734,444, No. 2,833,827, German Patent No. 2,904,626
No. 3,604,580 or 3,604,5
81, a sulfonium salt described in J. No. 81; V. Crivel
lo et al, Macromorecules, 1
0 (6), 1307 (1977), or J.I. V. Cr
ivello et al, J. Mol. Polymer Sc
i. , Polymer Chem. Ed. , 17,104
7 (1979), C.I. S. We
n et al, Teh, Proc. Conf. Ra
d. Curing ASIA, p478 Tokyo,
Octon (1988).

Examples of the counter ion of the onium salt include tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethyl Benzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol -5-sulfonic acid, 2-
Methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, p-toluenesulfonic acid and the like can be mentioned. Among these, in particular, hexafluorophosphoric acid,
Alkyl aromatic sulfonic acids such as triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid are preferred.

The onium salt is preferably added in an amount of 1 to 50% by weight, more preferably 5 to 30% by weight, based on the total solid content of the material constituting the first layer.
It is particularly preferable to add 〜30% by weight.

Further, in order to further improve the sensitivity,
Cyclic anhydrides, phenols, and organic acids can be used in combination. As the cyclic acid anhydride, US Pat.
Phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride described in US Pat. No. 5,128;
3,6-Endoxy-Δ4-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 ', 4 "-trihydroxytriphenylmethane,
4,4 ', 3 ", 4" -tetrahydroxy-3,5
3 ', 5'-tetramethyltriphenylmethane and the like. Further, as organic acids, JP-A-60-88
942, JP-A-2-96755, and the like, and include sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphoric esters, and carboxylic acids. 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 can be mentioned. The proportion of the above cyclic acid anhydride, phenols and organic acids in the printing plate material is 0.05 to 2%.
It is preferably 0% by weight, more preferably 0.1 to 15% by weight, particularly preferably 0.1 to 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, stearic acid monoglyceride, polyoxyethylene nonyl phenyl ether, and the like. 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 amphoteric surfactant in the printing plate material is preferably 0.05 to 15% by weight, and more preferably 0.1 to 5% by weight.

In the printing plate material of the present 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 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,
For example, oligomers and polymers of trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid are 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. 9-32893 previously proposed by the present inventors.
A crosslinkable compound having an alkali dissolution inhibiting action described in the specification of JP-A No. 7 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 use, 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 coating properties,
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, and titanium. The content of the foreign element in the alloy is at most 10% by weight or less. Particularly preferred aluminum 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 about 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. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. 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.

The anodizing treatment conditions vary depending on the electrolyte used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C., and the current density is 5 to 60 A. / Dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are appropriate. 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 present invention comprises a support and a positive photosensitive layer containing the photosensitive composition according to the present 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 which may have 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 phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent, glycine and β
-Selected from amino acids such as alanine, and hydrochlorides of amines having a hydroxy group such as triethanolamine hydrochloride, but may be used in combination of two or more.

This 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 coverage of the organic undercoat layer, 2 to 200 mg / m ² are suitable, 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 planographic printing plate precursor produced as described above is usually subjected to image exposure and development processing. The light source of the actinic ray used for image exposure has a wavelength of 760 to 760.
Examples thereof include a solid-state laser and a semiconductor laser that emit 1200-nm infrared rays. 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 silicate, tribasic sodium phosphate, tribasic potassium phosphate,
Ammonium phosphate, dibasic sodium phosphate, dibasic potassium phosphate, dibasic ammonium phosphate, sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium borate, potassium borate, boric acid Ammonium,
Inorganic alkali salts such as sodium hydroxide, ammonium hydroxide, potassium hydroxide and lithium hydroxide. Also, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine and pyridine are also used.

These 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, an organic carboxylic acid, an antifoaming agent, and a water softener. Can also 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 an unnecessary image portion (for example, a film edge mark of the original film), it is 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. 2-1293, to an unnecessary image portion, leaving the image to stand for a predetermined time, and then rinsing with water. A method described in JP-A-59-174842, in which an actinic ray guided by an optical fiber is applied to an unnecessary image portion and then developed, can also be used.

The lithographic printing plate obtained as described above can be subjected to a printing step after coating with a desensitizing gum if desired. Is subjected to a burning process. In the case where the lithographic printing plate is subjected to a burning treatment, prior to the burning treatment, JP-B Nos. 61-2518 and 55-28062,
It is preferable to treat with a surface-regulating liquid as described in JP-A-62-31859 and JP-A-61-159655. As the method, a method of applying the printing solution on a lithographic printing plate with a sponge or absorbent cotton impregnated with the surface conditioning solution, or immersing the printing plate in a vat filled with the surface conditioning solution, 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, 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.

[0097]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.
However, the scope of the present invention is not limited to these examples. (Examples 1 to 4) [Preparation of substrate] 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
Substrate A was obtained. The following undercoat liquid is applied to the substrate A, and the coating film is applied.
After drying at 90 ° C. for 1 minute, a substrate B was obtained. Application of coating after drying
The amount is 10mg / m^TwoMet.

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

The following substrate was prepared by changing the infrared absorbing agent in the following photosensitive solution 1 as shown in Table 1 below, and each was applied so that the coating amount became 1.8 g / m ^2. 1 to 4 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 (alkali water (Soluble polymer compound) ・ Infrared absorber described in Table 1 0.2 g (compound represented by the general formula (I)) ・ Dye in which the counter anion of Victoria Pure Blue BOH is 1-naphthalenesulfonic acid anion. 02 g-Fluorosurfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0.05 g-γ-butyrolactone 3 g-Methyl ethyl ketone 8 g-1-methoxy-2-propanol 7 g

(Comparative Example 1)
The lithographic printing plate precursor of Comparative Example 1 was prepared in exactly the same manner as in Example 1 except that the infrared absorber represented by the general formula (I) was replaced by the infrared absorber B-1 having the following structure. Obtained.

[0102]

Embedded image

Examples 5 to 8 <Synthesis Example (Copolymer 1)> Methacrylic acid 3 was placed in a 500 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel.
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, 4.61 g (0.01%) of N- (p-aminosulfonylphenyl) methacrylamide was placed in a 20 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel.
92 mol), and 2.94 g (0.02 g) of ethyl methacrylate.
58 mol), 0.80 g (0.015 g) of acrylonitrile
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 4.61
g, 2.94 g of ethyl methacrylate, 0.80 g of acrylonitrile, N, N-dimethylacetamide and "V-
65 "and a mixture of 0.15 g was added dropwise with a dropping funnel over 2 hours. After the addition was completed, the obtained mixture was further stirred at 65 ° C. for 2 hours. After completion of the reaction, methanol (40 g) was added to the mixture, and the mixture was cooled. The obtained mixture was added to 2 liters of water while stirring the water. The mixture was stirred for 30 minutes, and the precipitate was taken out by filtration and dried. 15 g of a white solid was obtained. The weight average molecular weight of this copolymer 1 (polystyrene standard) was measured by gel permeation chromatography and found to be 53,000.

The same substrate as used in Examples 1 to 4
In the following photosensitive solution 2, an infrared absorbing agent was used in the following Table 1.
Were prepared as described above, and the coating amount of each was 1.8.
g / m ^TwoLithographic printing plates of Examples 5 to 8
I got the original.

<Composition of Photosensitive Liquid 2> 0.75 g of the copolymer 1 (alkali water-soluble polymer compound) m, p-cresol novolak (m / p ratio = 6/4, weight average molecular weight 3500, Unreacted cresol 0.5% by weight) 0.25 g (Alkaline water-soluble polymer compound) ・ Tetrahydrophthalic anhydride 0.03 g ・ Infrared absorbent described in Table 1 0.017 g (Represented by general formula (I)・ Dye in which the counter ion of Victoria Pure Blue BOH is converted to 1-naphthalenesulfonic acid anion 0.015 g ・ Fluorinated surfactant (MegaFac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0 .05 g ・ γ-butyrolactone 10 g ・ Methyl ethyl ketone 10 g ・ 1-methoxy-2-propanol 1 g

(Comparative Example 2)
The lithographic printing plate precursor of Comparative Example 2 was carried out in exactly the same manner as in Example 5, except that the infrared absorbing agent represented by the general formula (I) was replaced by the infrared absorbing agent B-1 shown in the above structure. I got

[Performance Evaluation of Lithographic Printing Plate Precursor] The lithographic printing plate precursors of Examples 1 to 8 and Comparative Examples 1 and 2 produced as described above were evaluated for performance according to the following criteria. Table 1 shows the evaluation results.

(Evaluation of Image Formability: Sensitivity and Development Latitude) The obtained lithographic printing plate precursor was exposed to light using a semiconductor laser having a wavelength of 840 nm. 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 portion obtained with each developing solution was measured using two levels of those diluted with, and the irradiation energy of laser corresponding to the line width was obtained, and this was defined 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 fluctuation of the sensitivity was 20 mJ / cm ² or less, the storage stability was good and evaluated as a practically usable level.

[0112]

[Table 1]

From the results shown in Table 1, it can be seen that the lithographic printing plate precursors of Examples 1 to 10 were all of Comparative Examples 1 and 2 using the infrared absorbent B-1 having no long-chain alkyl group introduced at the N-position. It can be seen that the sensitivity to the infrared laser is higher than that of the lithographic printing plate precursor. In addition, the difference in sensitivity between the two diluted concentrations of the developing solution was 20 mJ / cm ² or less, which is practically required in any of the examples, and it was confirmed that the developing latitude was excellent. Furthermore, from the evaluation results of storage stability, all the lithographic printing plate precursors according to the present invention require a practically required sensitivity variation of 20 m before and after storage.
It was confirmed that it was J / cm ² or less. Therefore,
The lithographic printing plate precursor according to the invention was evaluated as having good storage stability.

(Examples 9 to 12) The substrate A used in Example 5 was treated with a 2.5% by weight aqueous solution of sodium silicate at 30 ° C. for 1 hour.
After treating for 0 second, the following undercoat liquid was applied, and the coating film was dried at 90 ° C. for 1 minute to obtain a substrate C. The coating amount of the coating film after drying is 15
mg / m ² .

<Composition of undercoat liquid>-0.3 g of the following copolymer having a molecular weight of 28,000-100 g of methanol-1 g of water

[0116]

Embedded image

The same photosensitive liquid 2 as used in Examples 5 to 8 was applied to the obtained substrate C so that the coating amount was 1.8 g / m ^2, and the lithographic printing plate precursors of Examples 9 to 12 were applied. I got

(Comparative Example 3) In Example 9, the photosensitive solution 1
The lithographic printing plate precursor of Comparative Example 3 was carried out in exactly the same manner as in Example 9 except that the infrared absorbent represented by the general formula (I) was replaced by the infrared absorbent B-1 represented by the above structure. I got

The lithographic printing plate precursors of Examples 9 to 12 and Comparative Example 3 were obtained at a main scanning speed of 5 m / sec using a semiconductor laser having an output of 500 mW, a wavelength of 830 nm, and a beam diameter of 17 μm (1 / e ² ). After exposure, Fuji Photo Film Co., Ltd. was charged with two types of developers (Developer 1 and Developer 2) having the following composition and different rinse ratios, and a rinse solution FR-3 (diluted 1: 7). It was developed using a PS processor 900VR and the sensitivity and development latitude were recorded.
The storage stability was evaluated in the same manner as in Examples 1 to 8. Table 2 shows the results.

<Developer 1> ・ D-sorbitol 5.1 parts by weight ・ Sodium hydroxide 1.1 parts by weight ・ Triethanolamine / ethylene oxide adduct (30 mol) 0.03 parts by weight ・ Water 93.9 parts by weight Parts <Developer 2> • D-sorbitol 5.1 parts by weight • Sodium hydroxide 1.1 parts by weight • Triethanolamine / ethylene oxide adduct (30 mol) 0.03 parts by weight • Water 140.7 parts by weight

[0121]

[Table 2]

From the results in Table 2, it can be seen that the lithographic printing plate precursors of Examples 9 to 12 all used the lithographic printing plate of Comparative Example 3 using the infrared absorbent B-1 having no long-chain alkyl group introduced at the N-position. It can be seen that the sensitivity to the infrared laser is higher than that of the original plate. In addition, the difference in sensitivity between the two dilution concentrations of the developing solution was 20 mJ / p, which is practically required in any of the examples, even when a non-silicate developing solution was used.
cm ² or less, which was confirmed to be excellent in development latitude. Furthermore, from the evaluation results of storage stability, it was confirmed that the lithographic printing plate precursors of the present invention all had a sensitivity variation before and after storage of 20 mJ / cm ² or less, which is required for practical use. Therefore, the planographic printing plate precursor according to the invention was evaluated as having good storage stability.

As can be seen from the above Examples, the present invention uses the above-mentioned specific infrared absorbing agent to obtain high sensitivity and stability of sensitivity when using developers having different concentrations.
That is, it was found that a photosensitive composition having good development latitude and good storage stability can be obtained. The lithographic printing plate precursor using this photosensitive composition was capable of direct plate making using an infrared laser, had high sensitivity, and had good development latitude and storage stability.

[0124]

The photosensitive composition of the present invention has a wide development latitude and is excellent in image formability, and its image formability does not decrease even after long-term storage, and the storage stability is good. Further, a lithographic printing plate using this photosensitive composition is a positive type lithographic printing plate for direct plate making capable of forming an image with an infrared laser, and has an effect of being excellent in image formability and storage stability.

 ────────────────────────────────────────────────── ─── Continued on front page F term (reference) 2H025 AA00 AA01 AA04 AB03 AC08 AD03 CB42 CB43 CB45 CB52 CC20 FA03 FA17 2H096 AA07 AA08 BA09 BA16 BA20 EA04 GA08 2H114 AA04 AA23 AA24 BA05 BA06 BA10 DA22 DA23 DA41 DA59 DA59

Claims (4)

[Claims] (1) Infrared light represented by the following general formula (I)
A line absorber and (b) water-insoluble and alkali
Contains a polymer compound soluble in aqueous solution,
Irradiation changes solubility in alkaline aqueous solution
A photosensitive composition comprising: Embedded imageWhere X¹, X^TwoIs each independently -CR⁷R⁸-, -S
-, -Se-, -NR ⁹-, -CH = CH- or -O
Represents-. R¹And R^TwoAre each independently a carbon atom
Represents an alkyl group of 9 to 30;^Three, R^Four, R^FiveAnd R⁶
Each independently represents an atom having 1 to 10 hydrogen atoms and 1 to 10 carbon atoms.
Represents a alkyl group;^ThreeAnd R^FourOr R^FiveAnd R⁶Are joined to each other
5 or 6-membered aliphatic ring, 6-membered aromatic ring, aromatic
10-membered ring, 6-membered substituted aromatic ring or 10-membered substituted aromatic ring
May represent a plurality of atoms necessary to form R⁷,
R⁸Is each independently an alkyl having 1 to 18 carbon atoms
A aryl group having 6 to 18 carbon atoms;⁹Is
Alkyl group having 1 to 18 carbon atoms, 6 to 18 carbon atoms
Represents an aryl group. Z is a hepta which may have a substituent
Represents a methine group, wherein the substituent is a group having 8 or less carbon atoms.
An alkyl group, a halogen atom, and an amino group. This hep
A methine group is one in which the substituents on the two methine carbons are
A cyclohexene ring or cyclopen formed by bonding to
It may contain a ten ring. This ring is
The substituent on the ring structure may be a carbon atom
Selected from alkyl groups or halogen atoms of the number 6 or less
You. Q represents a counter ion. 2. The photosensitive composition according to claim 1, wherein the counter ion Q of the infrared absorbent represented by the general formula (I) is represented by the following general formula (II). Embedded image In the formula, A represents an atom selected from the group consisting of B, P, As, Sb, Cl, and Br, and Y represents a halogen atom or an oxygen atom. m represents an integer of 1 to 6. 3. The photosensitive composition according to claim 1, wherein the counter ion Q of the infrared absorbent represented by the general formula (I) is a counter ion having a sulfonic acid structure. 4. The method according to claim 1, further comprising the steps of:
A lithographic printing plate precursor comprising a photosensitive layer comprising the photosensitive composition according to any one of the above.