JP2006171689A - Photosensitive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition having high sensitivity to the oscillation wavelength of an inexpensive short-wavelength semiconductor laser, excellent in work efficiency, economical efficiency, printing durability, stain resistance and storage stability, and useful as a photosensitive layer of a lithographic printing original plate for scanning exposure. <P>SOLUTION: The photosensitive composition contains (A) a sensitizing dye represented by formula (1), (B) an initiator compound and (C) a polymerizable compound. In the formula, A represents an aromatic ring which may have a substituent or a heterocycle; R3 represents H or a monovalent nonmetallic atomic group; R4 and R5 each independently represent a monovalent nonmetallic atomic group; R6 represents H or a monovalent nonmetallic atomic group; A and R3-R6 can form an aliphatic or aromatic ring by bonding to each other; and Z represents a 5- or 6-membered structure containing a hetero atom. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a photosensitivity that can be used for image forming materials such as three-dimensional stereolithography, holography, planographic printing plates, color proofs, photoresists, and color filters, and photocurable resin materials such as inks, paints, and adhesives. Relates to the composition. More particularly, the present invention relates to a photosensitive composition that can be directly made from a digital signal of a computer or the like using various lasers, and is suitably used as a so-called lithographic printing plate material capable of direct plate making.

Conventionally, as a lithographic printing plate, a PS plate having a configuration in which a lipophilic photosensitive resin layer is provided on a hydrophilic support has been widely used. As the plate making method, usually, mask exposure (surface After exposure), the desired printing plate was obtained by dissolving and removing the non-image area.
In recent years, digitization techniques for electronically processing, storing, and outputting image information using a computer have become widespread, and various new image output methods corresponding to the technology have come into practical use. As a result, computer-to-plate (CTP) technology that scans highly directional light such as laser light in accordance with digitized image information and directly manufactures a printing plate without using a lith film is desired. Obtaining a printing plate precursor adapted to this is an important technical issue.

  As one of methods for obtaining such a lithographic printing plate capable of scanning exposure, a method of forming an ink receptive resin layer region on a support having a hydrophilic surface is employed. This is a material in which a negative photosensitive layer that is cured by scanning exposure to form an ink receptive region is provided on a support, and has a configuration using a photopolymerization composition excellent in photosensitive speed. Some have been proposed and are already in practical use. The lithographic printing plate precursor having such a constitution has desirable printing plate and printing performance that are easy to develop, and further have excellent resolution, thickness, printing durability, and stain resistance.

The photopolymerizable composition basically contains a polymerizable compound having an ethylenically unsaturated bond, a photopolymerization initiation system, and optionally a binder resin, and by scanning exposure, the photoinitiation system absorbs light, An active species such as an active radical is generated to cause and advance the polymerization reaction of the polymerizable compound, thereby curing the exposed area to form an image.
In such a photopolymerizable composition capable of scanning exposure, various photoinitiating systems excellent in photosensitivity have been disclosed (for example, see Non-Patent Documents 1 and 2). The photoinitiating system described in these documents is a light source when applied to a conventional CTP system using a long wavelength visible light source such as an Ar laser (488 nm) or an FD-YAG laser (532 nm) as an exposure light source. In the present situation where the output is not sufficiently high, sufficient sensitivity cannot be obtained, and a highly sensitive starting system that can be adapted to further high-speed exposure is desired.

On the other hand, in recent years, for example, semiconductor lasers that use InGaN-based materials and can continuously oscillate in the 350 nm to 450 nm region have been put into practical use. The scanning exposure system using these short-wave light sources has an advantage that an economical system can be constructed while having a sufficient output because a semiconductor laser can be manufactured at a low cost because of its structure. Furthermore, as compared with a system using a conventional FD-YAG or Ar laser, a photosensitive material having photosensitivity in a short wavelength region capable of working under a brighter safe light can be used. However, there is currently no known photoinitiating system having sufficient sensitivity for scanning exposure in such a short wavelength region of 350 nm to 450 nm.
In response to this, the applicants of the present application have proposed a photosensitive composition containing a sensitizing dye having a high sensitivity in this short wavelength region (see Patent Document 1), and a photoinitiating system including these sensitizing dyes and the like. Further enhancement of sensitivity is desired.

  Furthermore, for example, JPFaussier "Photoinitiated Polymerization-Theory and Applications": Rapra Review vol.9, Report, Rapra Technology (1998) and M. Tsunooka et al., Prog. Polym. Sci., 21, 1 (1996) As described, obtaining a highly sensitive photoinitiator system is a technology that is still widely desired in the imaging field. The photoinitiating system consisting of a sensitizing dye and an initiator compound can generate an acid and a base in addition to the above active radicals by selecting the initiator compound. For example, images such as stereolithography, holography, and color hard copy It is used in the field of manufacturing, manufacturing of electronic materials such as photoresists, and photocurable resin materials such as inks, paints, and adhesives. In these industrial fields, it is eagerly desired to find a sensitizing dye excellent in light absorption and sensitizing ability for the purpose of efficiently causing the decomposition of the initiator compound.

In addition, as a common problem to all image forming materials containing these photosensitive compositions, the problem of how to enlarge the ON / OFF of the image in the laser light irradiated portion and the unirradiated portion, that is, the image forming material There is a problem of achieving both high sensitivity and storage stability. Usually, the radical photopolymerization system is highly sensitive, but the sensitivity is greatly lowered due to polymerization inhibition by oxygen in the air. Therefore, means for providing an oxygen barrier layer on the image forming layer is taken. However, when an oxygen-blocking layer is provided, fogging due to dark polymerization or the like occurs, and storage stability deteriorates. Also, when the photoinitiating material in the photosensitive layer decomposes and disappears under storage conditions, the amount of active radicals generated by light irradiation is reduced, which is one of the causes of storage stability deterioration. Accordingly, it is difficult to achieve both high sensitivity and storage stability. The conventional technique has not obtained a satisfactory result, and a new technique that has not been conventionally required has been demanded.
Bruce M. Monroe et al., Chemical Revue, 93, (1993), p. 435-p. 448 RS Davidson, Journal of Photochemistry and Biology A: Chemistry, Vol. 73, (1993), p. 81-p. 96 JP 2000-258910 A

  The object of the present invention in consideration of the above problems is high sensitivity to an oscillation wavelength of 350 nm to 450 nm of an inexpensive shortwave semiconductor laser, and is excellent in workability, economy, printing durability, stain resistance, and storage stability. Another object of the present invention is to provide a photosensitive composition using a novel photoinitiating system useful as a photosensitive layer of a lithographic printing plate precursor for scanning exposure that is compatible with, for example, a CTP system.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have given a high photosensitivity to a novel photoinitiation system comprising a sensitizing dye having a specific structure and an initiator compound, particularly 350 nm to 450 nm. The present invention was completed by finding high sensitivity in the vicinity and excellent storage stability.
That is, the present invention is as follows.
1. (A) a sensitizing dye represented by the following general formula (1),
A photosensitive composition containing (B) an initiator compound capable of generating a radical, an acid or a base, and (C) a polymerizable compound which reacts with at least one of a radical, an acid or a base.

(In the general formula (1), A represents an aromatic ring or a heterocyclic ring which may have a substituent. R3 represents a hydrogen atom or a monovalent nonmetallic atomic group, and R4 and R5 each independently represents Represents a monovalent nonmetallic atomic group, R6 represents a hydrogen atom or a monovalent nonmetallic atomic group, and A, R3, R4, R5, and R6 are bonded to each other to form an aliphatic group or an aromatic group. Z represents a 5-membered or 6-membered ring structure containing a hetero atom.)

  In addition, in this invention, an initiator compound refers to the compound which produces | generates the radical, acid, or base used as the starting seed | species which starts and advances the polymerization (crosslinking) reaction of the coexisting polymeric compound by provision of energy.

2. (A) a sensitizing dye represented by the following general formula (2),
A photosensitive composition containing (B) an initiator compound capable of generating a radical, an acid or a base, and (C) a polymerizable compound which reacts with at least one of a radical, an acid or a base.

(In the general formula (2), A represents an aromatic ring or a hetero ring which may have a substituent, X represents an oxygen atom, a sulfur atom, or -NR1-. R1, R2, R3, and R6 represent Each independently represents a hydrogen atom or a monovalent non-metallic atomic group, and R 4 and R 5 each independently represents a monovalent non-metallic atomic group A, R 3, R 4, R 5 and R 6 are bonded to each other; Aliphatic or aromatic rings can be formed.)

  3. 3. The photosensitive composition as described in 1 or 2 above, wherein the initiator compound capable of generating the (B) radical, acid or base is a hexaarylbiimidazole compound.

Although the mechanism of action of the present invention is not clear, the sensitizing dyes represented by the general formulas (1) and (2) are highly sensitive to wavelengths from 350 nm to 450 nm, and are inexpensive short-wave semiconductor lasers. Electron excited state with high sensitivity to irradiation (exposure) of oscillation wavelength, and electron transfer, energy transfer, heat generation, etc. related to the electron excited state due to this light absorption act on the coexisting initiator compound to chemistry the initiator compound. Causes changes to generate radicals, acids or bases. Furthermore, at least any one of radicals, acids and bases generated here causes irreversible changes such as color development, decoloration, and polymerization in the polymerizable compound that reacts. By using an addition polymerizable compound having an ethylenically unsaturated double bond, which is preferable among these compounds, the curing reaction starts and proceeds, and the exposed region is cured. For this reason, by using the photosensitive composition of the present invention, it has sufficient sensitivity for scanning exposure with a short-wave semiconductor laser, has excellent stability under yellow light, and can be handled under bright safe light. Has the advantage. Accordingly, in this photosensitive composition, a lithographic printing plate precursor using an addition polymerizable compound as a photosensitive layer is capable of recording with high sensitivity and exhibits printing performance excellent in safelight stability. Conceivable.
Moreover, it turned out that the photosensitive composition containing the sensitizing dye which has the specific structure of this invention is excellent in storage stability. The reason for this is not clear, but it has a relatively bulky substituent in the vicinity of the sensitizing dye structure. It is thought that this has an effect on improving the storage stability of the photosensitive composition.

  According to the present invention, for example, a CTP system that is highly sensitive to an oscillation wavelength of 350 nm to 450 nm of an inexpensive shortwave semiconductor laser and excellent in workability, economy, printing durability, stain resistance, and storage stability. A photosensitive composition useful as a photosensitive layer of a lithographic printing plate precursor for scanning exposure compatible with the above is provided.

Hereinafter, the present invention will be described in detail.
The photosensitive composition of the present invention comprises (A) a sensitizing dye represented by the general formula (1) or (2), (B) an initiator compound capable of generating a radical, an acid or a base, C) a polymerizable compound that reacts with at least one of a radical, an acid, and a base, and among these, (A) a sensitizing dye represented by general formula (1) or general formula (2) (B) An initiator compound capable of generating radicals, acids or bases constitutes the photoinitiating system of this photosensitive composition. In this system, (A) an initiator compound is produced by the action of electron transfer, energy transfer, heat generation, etc. due to the electronic excitation state caused by light absorption of the sensitizing dye represented by the general formula (1) or (2). Causes chemical changes to produce radicals, acids or bases.

First, this photoinitiating system will be described.
One of the characteristics of the sensitizing dye having a specific structure (A) useful for the photoinitiating system of the present invention is that it has particularly excellent absorption characteristics in the 350 nm to 450 nm region. Further, (A) a sensitizing dye having a specific structure efficiently causes decomposition of various (B) initiator compounds and exhibits very high photosensitivity. In general, the sensitization mechanism of a photoinitiating system comprising a sensitizing dye / initiator compound is (a) reductive decomposition of an initiator compound based on an electron transfer reaction from an electronically excited state of the sensitizing dye to the initiator compound, ( b) oxidative decomposition of the initiator compound based on electron transfer from the initiator compound to the electronically excited state of the sensitizing dye, (c) initiation based on energy transfer from the electronically excited state of the sensitizing dye to the initiator compound Although a route such as decomposition of an agent compound from an electronically excited state is known, it has been found that the sensitizing dye of the present invention causes any of these types of sensitizing reactions with excellent efficiency.

In order to obtain high sensitivity-high storage stability, the inventors of the present invention are very important that the sensitizing dye has a partial structure represented by the general formula (1) or the general formula (2). The mechanism of action is not clear. The reason why the sensitizing dye of the present invention is highly sensitive is that it exhibits a high-intensity emission (fluorescence and / or phosphorescence) spectrum. Is considered to have an effect on the efficiency of the reaction with the initiator compound since the lifetime of the excited state is relatively long. As another possibility, the partial structure represented by the general formula (1) or the general formula (2) can improve the efficiency of the initial stage of the sensitization reaction (electron transfer, etc.) and further the subsequent reaction leading to the decomposition of the initiator compound. There is a possibility that it contributes to efficiency improvement.
Next, as a factor that the sensitizing dye of the present invention has good storage stability, as described above, there is little decrease in sensitizing efficiency due to dye association under natural aging conditions, dark reaction with other components in the photosensitive layer, and the like. I think that this has an effect. As described above, the sensitizing dye plays an important role in the photoinitiated reaction, and the dark reaction in the photosensitive composition greatly reduces the radical generation amount (sensitivity reduction) by exposure, that is, the storage stability. Because it affects.

(A) Sensitizing dye The sensitizing dye used in the present invention is represented by the following formula (1).

  In the general formula (1), A represents an aromatic ring or a hetero ring which may have a substituent. R3 represents a hydrogen atom or a monovalent nonmetallic atomic group, and R4 and R5 each independently represent a monovalent nonmetallic atomic group other than a hydrogen atom. R6 represents a hydrogen atom or a monovalent nonmetallic atomic group. A, R3, R4, R5, and R6 can be bonded to each other to form an aliphatic or aromatic ring. Z represents a 5-membered or 6-membered ring structure containing a hetero atom. In the present invention, examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom.

  Here, Z represents a 5-membered or 6-membered ring structure containing a hetero atom. Specific examples include a pyrazolinone nucleus, an oxindole nucleus, a 2,4-thiazolidinedione nucleus, and a 2-thio-2,4-oxazolidine. Dione nucleus, 1,3-oxazolidine-4-one nucleus, thianaphthenone nucleus, thiazolidinedione nucleus, thiazolidinone nucleus, 2-imino-2-oxazolin-4-one nucleus, 2,4-imidazolidinedione nucleus, 2,4- Examples include an imidazolidinedione nucleus, an imidazolin-5-one nucleus, a furan-5-one nucleus, and a thioindoxyl nucleus, and these acidic nuclei may further have a substituent. Among these heterocyclic structures, a more preferred structure is a sensitizing dye represented by the following formula (2).

In the general formula (2), A represents an aromatic ring or a hetero ring which may have a substituent, and X represents an oxygen atom, a sulfur atom or —NR 1 —. R1, R2, R3, and R6 each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R4 and R5 each independently represent a monovalent nonmetallic atomic group. A, R3, R4, R5, and R6 can be bonded to each other to form an aliphatic or aromatic ring. )

Here, when R 1, R 2, R 3, R 4, R 5 and R 6 represent a monovalent nonmetallic atomic group, they preferably represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.
Next, preferred examples of R1, R2, R3, R4, R5, and R6 will be specifically described. Examples of preferable alkyl groups include linear, branched, and cyclic alkyl groups having 1 to 20 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, Butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s-butyl, Examples thereof include 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. Of these, 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.

As the substituent of the substituted alkyl group, a monovalent non-metallic atomic group other than hydrogen is used. Preferred examples include halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups, alkoxy groups. 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-diaryl Amino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy Group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy , Arylsulfoxy group, acyloxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N '-Arylureido group, N', N'-diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido group N′-alkyl-N-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group N′-aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-aryluree Id 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-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group , Alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group An alkylsulfinyl group, Arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group (hereinafter referred to as sulfonate group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkyls Rufinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkyl Sulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group (—PO ₃ H ₂₎ and its conjugated base group (hereinafter referred to as phosphonato group), di Rukiruhosuhono group _{(-PO 3 (alkyl) 2)} , diaryl phosphono group _{(-PO 3 (aryl) 2)} , alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )), monoalkyl phosphono group (- PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkylphosphonate group), monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as arylphosphonate group) ), Phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonatoxy group), dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO _3). (aryl) _2), alkylaryl phosphono group _{(-OPO 3 (alkyl) (aryl} )), monoalkyl phosphonates Oxy group (-OPO ₃ H (alkyl)) and its conjugated base group (hereinafter referred to as alkylphosphonato group), monoarylphosphono group (-OPO ₃ H (aryl)) and its conjugated base group (hereinafter And cyano group, nitro group, aryl group, heteroaryl group, alkenyl group, alkynyl group and silyl group.
Specific examples of the alkyl group in these substituents include the aforementioned alkyl groups, which may further have a substituent.

  Specific examples of the aryl group include phenyl group, biphenyl group, naphthyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group. , Ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl Group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophene Group, can be exemplified phosphonophenyl phenyl group.

  As the heteroaryl group, a group derived from a monocyclic or polycyclic aromatic ring containing at least one of nitrogen, oxygen and sulfur atoms is used, and examples of the heteroaryl ring in the particularly preferred heteroaryl group include Is, for example, thiophene, thiathrene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, indolizine, indazole, indazole, Purine, quinolidine, isoquinoline, phthalazine, naphthyridine, quinazoline, sinoline, pteridine, carbazole, carboline, phenanthrine, acridine, perimidine, phenanthrolin, phthalazine, phenalazine, phenoxazine, fura Emissions, phenoxazine and the like, they further may be benzo-fused or may have a substituent.

Examples of alkenyl groups include vinyl, 1-propenyl, 1-butenyl, cinnamyl, 2-chloro-1-ethenyl, etc. Examples of alkynyl include ethynyl, 1 -Propynyl group, 1-butynyl group, trimethylsilylethynyl group and the like. Examples of G ₁ in the acyl group (G ₁ CO—) include hydrogen and the above alkyl groups and aryl groups. Among these substituents, even more preferred are halogen atoms (—F, —Br, —Cl, —I), alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, N-alkylamino groups, 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 Group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonate group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfa group Moyl group, N-arylsulfur Amoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group, phosphonate group, dialkyl phosphono group, diaryl phosphono group, monoalkyl phosphono group, alkyl phosphonate group, monoaryl phosphono group, aryl phosphino group Examples include an onato group, a phosphonooxy group, a phosphonateoxy group, an aryl group, an alkenyl group, and an alkylidene group (such as a methylene group).

  On the other hand, examples of the alkylene group in the substituted alkyl group include divalent organic residues obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 20 carbon atoms. Can include linear alkylene groups having 1 to 12 carbon atoms, branched chains having 3 to 12 carbon atoms, and cyclic alkylene groups having 5 to 10 carbon atoms.

  Specific examples of preferable substituted alkyl groups as R1, R2, R3, R4, R5, and R6 obtained by combining the above substituents with an alkylene group include chloromethyl group, bromomethyl group, 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 Methoxycarbonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N- Methyl-N- (sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatopropyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N -Tolylsulfamoylpropyl group, N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphospho Phonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl 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.

  Specific examples of preferable aryl groups as R1, R2, R3, R4, R5, and R6 include those in which 1 to 3 benzene rings form a condensed ring, and a benzene ring and a 5-membered unsaturated ring form a condensed ring. Specific examples include phenyl group, naphthyl group, anthryl group, phenanthryl group, indenyl group, acenaphthenyl group, fluorenyl group, and among these, phenyl group, naphthyl group Is more preferable.

  Specific examples of preferred substituted aryl groups as R1, R2, R3, R4, R5, and R6 include monovalent nonmetallic atomic groups (other than hydrogen atoms) as substituents on the ring-forming carbon atoms of the aforementioned aryl groups. Those having the following groups are used. Examples of preferred substituents include the alkyl groups, substituted alkyl groups, and those previously shown as substituents in the substituted alkyl group. Preferred examples of such a substituted aryl group include biphenyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, fluorophenyl group, chloromethylphenyl group, trifluoromethylphenyl group. Hydroxyphenyl group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl group, phenoxyphenyl group, methylthiophenyl group, tolylthiophenyl group, ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, acetyloxyphenyl group, Benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group, acetylaminophenyl group, N-methylbenzoylaminophenyl group, cal Xiphenyl group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, carbamoylphenyl group, N-methylcarbamoylphenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) carbamoylphenyl group N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, phosphonophenyl group, phosphonatophenyl group, diethylphosphonophenyl group, diphenylphosphoro Phenyl group, methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonatophenyl group, allylphenyl group, 1-propenylmethylphenyl group, 2-butenylphenyl group, 2-methylallylphenyl Group, 2-methylpropenylphenyl group, 2-propynylphenyl group, 2-butynylphenyl group, 3-butynylphenyl group, and the like.

  A more preferred example of R1 includes a substituted or unsubstituted aryl group, and a more preferred example of R2 and R6 includes a substituted or unsubstituted alkyl group. Particularly preferred examples of R2 include an alicyclic alkyl group, and specific examples include a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Preferred examples of R3, R4, and R5 include a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group. Particularly preferred examples include R3 and R4, or R4 and R5, or R3. This is a case where R5 is bonded with a divalent linking group. Specifically, it is preferable that a cycloalkyl structure is formed between R3, R4 and R5. Preferable cycloalkyl structures include a cyclohexyl structure, a cycloheptyl structure, a cyclooctyl structure, and an adamantane structure. The reason why these substituents are suitable is not clear, but by having such substituents, the interaction between the electronically excited state caused by light absorption and the initiator compound becomes particularly large, and the radical of the initiator compound The efficiency of generating an acid or base is improved (sensitivity improving effect), and a bulky structure is introduced adjacent to the imine structure, so that hydrolysis, oxidative decomposition, etc. from the photosensitive film due to decomposition of the imine structure It is conceivable that disappearance is suppressed (storage stability improving effect).

Next, A in the general formula (1) will be described. A represents an aromatic ring or a hetero ring which may have a substituent, and specific examples of the aromatic ring or hetero ring which may have a substituent include R1, R2, and R3 in the general formula (1). , R4, R5 and R6 are the same as those exemplified in the description.
Among them, preferable A includes an alkoxy group, a thioalkyl group, and an aryl group having an amino group, and more preferable A includes an aryl group having an amino group. Particularly preferred aryl groups having an amino group include dialkylaminoaryl groups and diarylaminoaryl groups. Specific examples include dimethylaminophenyl group, diethylaminophenyl group, piperidinophenyl group, morpholinophenyl group, and julolidine. Group and diphenylaminophenyl group.
Furthermore, preferred substituents on the dialkylaminoaryl group and diarylaminoaryl group include an alkoxy group, a thioalkyl group, and an alkylamino group, more preferably an alkoxy group, specifically a methoxy group, an ethoxy group, and a propyloxy group. Groups. The introduction of these substituents is effective for suppressing problems such as dye crystal precipitation in a developing machine, in order to improve the solubility of the sensitizing dye in the developer.

  Although the preferable specific example (Exemplary compound D1-Exemplary compound D49) of the sensitizing dye represented by General formula (1) based on this invention below is shown, this invention is not limited to these.

A method for synthesizing the compound represented by the general formula (1) will be described.
The compound represented by the general formula (1) is usually obtained by a condensation reaction between an acidic nucleus having an active methylene group and a substituted or unsubstituted aromatic ring or heterocyclic ring. These compounds are described in JP-B-59-28329. It can synthesize | combine with reference to a gazette. For example, as shown in the following reaction formula (1), a synthesis method using a condensation reaction of an acidic nucleus compound and a basic nucleus raw material having an aldehyde group or a carbonyl group on the heterocycle can be mentioned. The condensation reaction is carried out in the presence of a base, if necessary. As the base, generally used ones such as amines, pyridines (trialkylamine, dimethylaminopyridine, diazabicycloundecene DBU, etc.), metal amides (lithium diisopropylamide, etc.), metal alkoxides ( Sodium methoxide, potassium-t-butoxide, etc.) and metal hydrides (sodium hydride, potassium hydride, etc.) can be used without limitation. In the reaction formula (1), Y represents N—C (R3) (R4) (R5).

Another desirable synthesis method is a method according to the following reaction formula (2). That is, as an acidic nucleus compound in the reaction formula (1), an acidic nucleus compound in which Y is a sulfur atom is used as a starting material, and a dye precursor is obtained by a condensation reaction of a basic nucleus material having an aldehyde group or a carbonyl group on the heterocycle. The process up to the step of synthesizing the body is carried out in the same manner as in the reaction formula (1), and then the dye precursor is further reacted with a sulfur atom to form a metal sulfide and a metal salt and water or 1 This is a reaction in which a secondary amine compound (R—NH ₂ : R represents a monovalent nonmetallic atomic group) is allowed to act.
Among these, the reaction represented by the reaction formula (2) has a high yield of each reaction and is particularly preferable in terms of synthesis efficiency. In particular, when the novel compound represented by the general formula (2) is synthesized, The reaction represented by the reaction formula (2) is useful.

In the reaction formula (2), M ^{n +} X _n represents a metal salt that can form a metal sulfide by chemically interacting with the sulfur atom of the thiocarbonyl group. As specific compounds, for example, M is Al, Au, Ag, Hg, Cu, Zn, Fe, Cd, Cr, Co, Ce, Bi, Mn, Mo, Ga, Ni, Pd, Pt, Ru, Rh. , Sc, Sb, Sr, Mg, Ti, etc., and X is F, Cl, Br, I, NO ₃ , SO ₄ , NO ₂ , PO ₄ , CH ₃ CO _2, etc., AgBr, AgI, AgF, AgO, AgCl, Ag ₂ O, Ag (NO ₃ ), AgSO ₄ , AgNO ₂ , Ag ₂ CrO ₄ , Ag ₃ PO ₄ , Hg ₂ (NO ₃ ) ₂ , HgBr ₂ , Hg ₂ Br ₂ , HgO, HgI ₂ , Hg (NO ₃ ) ₂ , Hg (NO ₂ ) ₂ , HgBr ₂ , HgSO ₄ , Hg ₂ I ₂ , Hg ₂ SO ₄ ,
Hg (CH ₃ CO ₂ ) ₂ , AuBr, AuBr ₃ , AuI, AuI ₃ , AuF ₃ , Au ₂ O ₃ , AuCl, AuC 1 ₃ , CuCl, CuI, CuI ₂ , CuF ₂ , CuO, CuO ₂ , Cu (NO ₃ ) ₂ , CuSO ₄ , Cu ₃ (PO ₄ ) _{2 and} the like. Among these, a silver salt can be used as the most preferable metal salt in that it easily interacts with a sulfur atom.

The sensitizing dye represented by the general formula (1) used in the present invention can be further subjected to various chemical modifications for improving the characteristics of the photosensitive layer. For example, sensitizing dye and addition polymerizable compound structure (for example, acryloyl group or methacryloyl group) are bonded by a method such as covalent bond, ionic bond, hydrogen bond, etc. Unnecessary precipitation suppression of the dye from the subsequent film can be performed.
In addition, a partial structure having radical generating ability in a sensitizing dye and an initiator compound described later (for example, reductive decomposable sites such as alkyl halide, onium, peroxide, biimidazole, onium, biimidazole, borate, amine) , Trimethylsilylmethyl, carboxymethyl, carbonyl, imine, and other oxidatively cleavable moieties) can significantly increase the photosensitivity particularly in a low concentration of the starting system.

Furthermore, when the photosensitive composition of the present invention is used as a photosensitive layer of a lithographic printing plate precursor which is a preferred mode of use, it is hydrophilic for the purpose of enhancing the suitability for processing in an alkaline or aqueous developer. It is effective to introduce a functional site (carboxyl group and its ester, sulfonic acid group and its ester, ethylene oxide group or other acid group or polar group). In particular, ester-type hydrophilic groups have a relatively hydrophobic structure in the photosensitive layer, so that they have excellent compatibility, and in the developer, acid groups are generated by hydrolysis, resulting in increased hydrophilicity. Have.
In addition, for example, a substituent can be appropriately introduced in order to improve compatibility in the photosensitive layer and to suppress crystal precipitation. For example, in certain types of photosensitive systems, unsaturated bonds such as aryl groups and allyl groups may be very effective in improving compatibility. By introducing an obstacle, crystal precipitation can be remarkably suppressed. Further, by introducing a phosphonic acid group, an epoxy group, a trialkoxysilyl group, or the like, adhesion to an inorganic substance such as a metal or a metal oxide can be improved. In addition, a method such as polymerization of a sensitizing dye can be used depending on the purpose.

As the sensitizing dye used in the present invention, at least one sensitizing dye represented by the general formula (1) may be used. As long as it is represented by the general formula (1), for example, the modification described above may be used. The details of the usage, such as the structure of the dye used, whether it is used alone or in combination of two or more, and how much is added, are in line with the performance design of the final photosensitive material. It can be set appropriately. For example, the compatibility with the photosensitive layer can be increased by using two or more sensitizing dyes in combination.
In selecting the sensitizing dye, in addition to the photosensitivity, the molar extinction coefficient at the emission wavelength of the light source used is an important factor. By using a dye having a large molar extinction coefficient, the amount of the dye added can be made relatively small, which is economical and advantageous from the viewpoint of film properties of the photosensitive layer.
In the present invention, in addition to the specific sensitizing dye (A), other general-purpose sensitizing dyes can be used in combination as long as the effects of the present invention are not impaired.

Since the photosensitivity and resolution of the photosensitive layer and the physical properties of the exposure film are greatly affected by the absorbance at the light source wavelength, the addition amount of the sensitizing dye is appropriately selected in consideration of these. For example, the sensitivity decreases in a low region where the absorbance is 0.1 or less. Also, the resolution becomes low due to the influence of halation. However, for the purpose of curing a thick film of, for example, 5 μm or more, there is a case where such a low absorbance can be increased instead. Further, in a region where the absorbance is as high as 3 or more, most of the light is absorbed on the surface of the photosensitive layer, and the internal curing is inhibited. For example, when used as a printing plate, the film strength and the substrate adhesion are poor. It will be insufficient.
For example, when the photosensitive composition of the present invention is used in the photosensitive layer of a lithographic printing plate precursor using a relatively thin film thickness, the amount of the sensitizing dye added is such that the absorbance of the photosensitive layer is 0.1 to 1. .5, preferably 0.25 to 1. Since the absorbance is determined by the addition amount of the sensitizing dye and the thickness of the photosensitive layer, the predetermined absorbance can be obtained by controlling both conditions. The absorbance of the photosensitive layer can be measured by a conventional method. As a measuring method, for example, on a transparent or white support, a photosensitive layer having a thickness appropriately determined in a range where the coating amount after drying is necessary as a lithographic printing plate is formed, and a transmission type optical densitometer is used. Examples thereof include a method of measuring, a method of forming a photosensitive layer on a reflective support such as aluminum, and measuring a reflection density.
When the photosensitive composition of the present invention is used as a photosensitive layer of a lithographic printing plate precursor, the amount of the sensitizing dye represented by the general formula (1) or the general formula (2) is usually the same as that of the photosensitive layer. It is 0.05-30 mass parts with respect to 100 mass parts of all the solid components to comprise, Preferably it is 0.1-20 mass parts, More preferably, it is the range of 0.2-10 mass parts.

Next, the initiator compound (B) that is the second essential component of the photoinitiating system in the photosensitive composition of the present invention will be described.
(B) Initiator Compound The initiator compound in the present invention is a compound that generates a radical, an acid, or a base by causing a chemical change through interaction with an electronically excited state generated by light absorption of a sensitizing dye. Hereinafter, the radical, acid or base generated in this way is simply referred to as an active species. When these compounds are not present or when only the initiator compound is used alone, practically sufficient sensitivity cannot be obtained, but as one aspect of using the sensitizing dye and the initiator compound in combination, These can also be used as a single compound by an appropriate chemical method (such as linking of a sensitizing dye and an initiator compound through a chemical bond). Such a technical idea is disclosed in, for example, Japanese Patent No. 2720195.

  Usually, many of these active agents are considered to generate active species through the following initial chemical processes (1) to (3). That is, (1) reductive decomposition of an initiator compound based on an electron transfer reaction from an electronically excited state of a sensitizing dye to an activator, and (2) an electron transfer from the initiator compound to the electronically excited state of the sensitizing dye. Oxidative decomposition of the initiator compound based on (3) decomposition of the initiator compound from the electronically excited state based on energy transfer from the electronically excited state of the sensitizing dye to the initiator compound. Although it is often ambiguous as to which type (1) to (3) each of the initiator compounds belongs, the major feature of the sensitizing dye in the present invention is the initiation of any of these types. Even if combined with the agent compound, it has a very high sensitizing effect.

Specific initiator compounds known to those skilled in the art can be used without limitation. Specifically, for example, Bruce M. Monroe et al., Chemical Revue, 93, 435 (1993) and RSD Davidson, Journal of Photochemistry and biology A: Chemistry, 73.81 (1993); JPFaussier, “Photoinitiated Polymerization-Theory and Applications ": Rapra Review vol.9, Report, Rapra Technology (1998); M. Tsunooka et al., Prog. Polym. Sci., 21, 1 (1996)
Etc. are often described. In addition, as other compound groups having the functions of (1) and (2), FDSaeva, Topics in Current Chemistry, 156, 59 (1990); GGMaslak, Topics in Current Chemistry, 168, 1 (1993) HBShuster et al, JACS, 112, 6329 (1990); IDFEaton et al, JACS, 102, 3298 (1980) and other compounds that cause oxidative or reductive bond cleavage are also known It is done.

  The following are specific examples of preferred initiator compounds: (a) those that are reduced to cause bond cleavage to produce active species, (b) those that can be oxidized to cause bond cleavage to produce active species, and ( c) Others are classified and explained, but there are many cases where there is no general explanation as to which individual compounds belong to them, and the present invention is not limited to the description of these reaction mechanisms.

(A) Compound which is reduced to generate bond by cleaving bond. Compound having carbon-halogen bond: It is considered that carbon-halogen bond is reductively cleaved to generate active species (for example, Polymer Preprints , Jpn., 41 (3) 542 (1992)). As the active species, radicals and acids can be generated. Specifically, for example, in addition to halomethyl-s-triazines, halo which can be easily synthesized by those skilled in the art by the synthesis method described in MPHutt, EFElslager and LMMerbel, Journal of Heterocyclic Chemistry, 7, 511 (1970). Methyl oxadiazoles and the compounds described in German Patent Nos. 2641100, 3333450, 3021590, and 3021599 can be preferably used.

Compound having nitrogen-nitrogen bond or nitrogen-containing heterocycle-nitrogen-containing heterocycle bond: reductive bond cleavage (for example, described in J.Pys.Chem., 96, 207 (1992)) . Specifically, hexaarylbiimidazoles and the like are preferably used. The active species produced are lophine radicals, which together with a hydrogen donor if necessary, initiate radical chain reactions and are also known to form images using oxidation reactions with lophine radicals (J. Imaging Sci., 30 , 215 (1986)).

Compounds having an oxygen-oxygen bond: It is considered that an oxygen-oxygen bond is reductively cleaved to generate an active radical (for example, described in Polym. Adv. Technol., 1, 287 (1990)).
. Specifically, for example, organic peroxides are preferably used. A radical can be generated as an active species.

  Onium compounds: It is considered that carbon-hetero bonds and oxygen-nitrogen bonds are reductively cleaved to generate active species (for example, as described in J. Photopolym. Sci. Technol., 3, 149 (1990)). ) Specifically, for example, iodonium salts described in European Patent No. 104143, US Pat. No. 4,837,124, JP-A-2-150848, JP-A-2-96514, European Patents 370693 and 233567. Sulfonium salts described in U.S. Pat. Nos. 297443, 297442, 279210, 422570, U.S. Pat.Nos. 3,902,144, 4,933,377, 4760013, 4,734,444 and 2,833,827, Diazonium salts (such as benzenediazonium which may have a substituent), diazonium salt resins (formaldehyde resin of diazodiphenylamine), N-alkoxypyridinium salts and the like (for example, US Pat. No. 4,743,528, Kaisho 63-13834 No. 63-142345, JP-A 63-142346, JP-B 46-42363, etc., specifically 1-methoxy-4-phenylpyridinium tetrafluoroborate, etc. Further, compounds described in JP-B Nos. 52-147277, 52-14278, and 52-14279 are preferably used. Generates radicals and acids as active species.

Active esters: nitrobenzyl esters of sulfonic acid and carboxylic acid, esters of sulfonic acid and carboxylic acid and N-hydroxy compounds (N-hydroxyphthalimide, oxime, etc.), sulfonic acid esters of pyrogallol, naphthoquinone diazide-4 -Sulfonates can be reductively decomposed. As the active species, radicals and acids can be generated. Specific examples of the sulfonic acid esters include European Patent Nos. 0290750, 046083, 156153, 271851, 0388343, U.S. Pat. Nos. 3,901,710 and 4,181,531, 60-198538, Japanese Patent Laid-Open No. 53-133022, nitrobenzester compounds, European Patent No. 099672, No. 84515, No. 199672, No. 0441115, No. 0101122, US Pat. No. 4,618,564, JP-A-4371605, JP-A-4431774, JP-A Nos. 64-18143, JP-A-2-245756, JP-A-4-365048, iminosulfonate compounds, JP-B-62-2223, Kosho 63-14340, JP 59-17483 Issue JP-like compounds described are listed, further, it includes, for example, compounds as shown below.

(In the formula, Ar represents an aromatic group or an aliphatic group which may be substituted.)
Moreover, it is also possible to produce | generate a base as an active species, for example, the following compound groups are known.

  Ferrocene and iron arene complexes: An active radical can be reductively generated. Specifically, for example, they are disclosed in JP-A-1-304453 and JP-A-1-152109.

(In the formula, R represents an aliphatic group or an aromatic group which may be substituted.)
Disulfones: Reducing S—S bond reductively and generating an acid. For example, diphenyl disulfones as described in JP-A No. 61-166544 are known.

(B) Oxidized to generate an active species by cleaving a bond Alkylate complex: It is considered that a carbon-hetero bond is oxidatively cleaved to generate an active radical (for example, J. Am. Chem. Soc ., 112, 6329 (1990)). Specifically, for example, triarylalkyl borates are preferably used.

  Alkylamine compound: It is considered that the C—X bond on carbon adjacent to nitrogen is cleaved by oxidation to generate an active radical (for example, J. Am. Chem. Soc., 116, 4211 (1994)). be written). X is preferably a hydrogen atom, a carboxyl group, a trimethylsilyl group, a benzyl group or the like. Specific examples include ethanolamines, N-phenylglycines, N-trimethylsilylmethylanilines, and the like.

  Sulfur-containing and tin-containing compounds: Compounds in which the nitrogen atoms of the above-described amines are replaced with sulfur atoms and tin atoms can generate active radicals by the same action. Further, a compound having an SS bond is also known to be sensitized by SS cleavage.

  α-Substituted methylcarbonyl compound: An active radical can be generated by oxidative cleavage of the carbonyl-α carbon bond. Moreover, what converted carbonyl into the oxime ether also shows the same effect | action. Specifically, 2-alkyl-1- [4- (alkylthio) phenyl] -2-morpholinopronone-1 and these and a hydroxylamine were reacted, and then N—OH was etherified. Mention may be made of oxime ethers.

  Sulfinic acid salts: An active radical can be reductively generated. Specific examples include sodium arylsulfinate.

(C) Others Although the sensitization mechanism is not clear, many of them can function as initiator compounds. Examples thereof include organometallic compounds such as titanocene and ferrocene, aromatic ketones, acylphosphine, bisacylphosphine and the like, and active species can generate radicals and acids.

  Hereinafter, among the initiator compounds used in the present invention, preferred compounds particularly excellent in sensitivity and stability are specifically exemplified.

(1) Halomethyltriazines Examples include compounds represented by the following formula [II]. Excellent radical generation and acid generation ability.

In the formula [II], X represents a halogen atom. Y ¹ represents —CX ′ ₃ , —NH ₂ , —NHR ¹ ′, —NR ¹ ′ ₂ , —OR ¹ ′. Here, R ¹ ′ represents an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. R ¹ represents —CX ₃ , an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or a substituted alkenyl group.

  Specific examples of such compounds include, for example, compounds described in Wakabayashi et al., Bull. Chem. Soc. Japan, 42, 2924 (1969), such as 2-phenyl-4,6-bis (trichloromethyl)- S-triazine, 2- (p-chlorophenyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -S-triazine, 2 -(P-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (2 ', 4'-dichlorophenyl) -4,6-bis (trichloromethyl) -S-triazine, 2,4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6-bis (trichloromethyl) -S-triazine, 2-n-nonyl-4,6-bis (trichloromethyl)- S- Triazine, 2- (α, α, β- trichloroethyl) -4,6-bis (trichloromethyl) -S- triazine. In addition, compounds described in GB 1388492, for example, 2-styryl-4,6-bis (trichloromethyl) -S-triazine, 2- (p-methylstyryl) -4,6-bis (trichloromethyl) ) -S-triazine, 2- (p-methoxystyryl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxystyryl) -4-amino-6-trichloromethyl-S-triazine Compounds described in JP-A-53-133428, such as 2- (4-methoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxy- Naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- [4- (2-ethoxyethyl) -naphth-1-yl] -4,6-bis-tri Lormethyl-S-triazine, 2- (4,7-dimethoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (acenaphtho-5-yl) -4,6-bis Examples include compounds described in German Patent No. 3337024, such as -trichloromethyl-S-triazine, and the like.

  Further, compounds described in J. Org. Chem., 29, 1527 (1964) by FC Schaefer et al., For example, 2-methyl-4,6-bis (tribromomethyl) -S-triazine, 2,4,6-tris (Tribromomethyl) -S-triazine, 2,4,6-tris (dibromomethyl) -S-triazine, 2-amino-4-methyl-6-tribromomethyl-S-triazine, 2-methoxy-4-methyl And -6-trichloromethyl-S-triazine.

  Further, compounds described in JP-A No. 62-58241, for example, the following compounds can be mentioned.

  Further, compounds described in JP-A-5-281728, for example, the following compounds can be mentioned.

(2) Titanocenes Any titanocene compound that is particularly preferably used as an initiator compound may be any titanocene compound that can generate active species when irradiated with light in the presence of the sensitizing dye. Well, for example, JP-A-59-152396, JP-A-61-151197, JP-A-63-41483, JP-A-63-41484, JP-A-2-249, JP-A-2-291, Known compounds described in JP-A-3-27393, JP-A-3-12403, and JP-A-6-41170 can be appropriately selected and used.

More specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5 , 6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2 , 4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Difluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti- Bis-2, 3, , 6-tetrafluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6- And difluoro-3- (pyr-1-yl) phenyl) titanium.

(3) Borate salt compounds Borate salts represented by the following formula [III] are excellent in radical generating ability.

In the formula [III], R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may be the same or different from each other, and each represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl. A group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted heterocyclic group, wherein R ⁵¹ , R ⁵² , R ^53, and R ⁵⁴ are bonded to form a cyclic structure. Also good. However, at least one of R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ is a substituted or unsubstituted alkyl group. Z ⁺ represents an alkali metal cation or a quaternary ammonium cation.

The alkyl groups of R ^{51 to} R ⁵⁴ include straight chain, branched, and cyclic groups, and those having 1 to 18 carbon atoms are preferable. Specifically, methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, octyl, stearyl, cyclobutyl, cyclopentyl, cyclohexyl and the like are included. Examples of the substituted alkyl group include the above alkyl groups, halogen atoms (for example, -Cl, -Br, etc.), cyano groups, nitro groups, aryl groups (preferably phenyl groups), hydroxy groups, the following groups,

(Here, R ⁵⁵ and R ⁵⁶ independently represent a hydrogen atom, an alkyl group having 1 to 14 carbon atoms, or an aryl group.), —COOR ⁵⁷ (wherein R ⁵⁷ represents a hydrogen atom, having 1 to 14 carbon atoms. an alkyl group or an aryl group,), -. COOR ⁵⁸ or -OR ⁵⁹ (wherein R ⁵⁸ is included those having as a substituent a) an alkyl group or an aryl group, 1 to 14 carbon atoms..

Examples of the aryl group of R ^{51 to} R ⁵⁴ include 1 to 3 ring aryl groups such as a phenyl group and a naphthyl group, and examples of the substituted aryl group include the substitution of the above substituted alkyl group with the above aryl group. And those having an alkyl group having 1 to 14 carbon atoms.

Examples of the alkenyl group represented by R ^{51 to} R ⁵⁴ include linear, branched, and cyclic groups having 2 to 18 carbon atoms, and examples of the substituent of the substituted alkenyl group include the substituents of the substituted alkyl group. Is included.

Examples of the alkynyl group of R ^{51 to} R ⁵⁴ include linear or branched groups having 2 to 28 carbon atoms, and examples of the substituent of the substituted alkynyl group include those listed as the substituents of the substituted alkyl group. included.

In addition, examples of the heterocyclic group of R ^{51 to} R ⁵⁴ include a 5-membered or more, preferably 5 to 7-membered heterocyclic group containing at least one of N, S, and O. May contain a condensed ring. Furthermore, you may have what was mentioned as a substituent of the above-mentioned substituted aryl group as a substituent.

  Specific examples of the compound represented by the formula [III] include compounds described in the specifications of U.S. Pat. Nos. 3,567,453 and 4,434,891, European Patent Nos. 109772 and 109773, and those shown below. Can be mentioned.

(4) Hexaarylbiimidazoles Excellent in stability and capable of generating highly sensitive radicals. Specifically, 2,2′-bis (o
-Chlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2 '-Bis (o, p-dichlorophenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra ( m-methoxyphenyl) biimidazole, 2,2′-bis (o, o′-dichlorophenyl) -4,4 ′
, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-nitrophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-methylphenyl) ) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluoromethylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole and the like. .

(5) Onium salt compounds 15 (5B), 16 (6B), and 17 (7B) group elements of the periodic table, specifically N, P, As, Sb, Bi, O, S, Se, Te, I The onium compound is an initiator compound having excellent sensitivity. Particularly, iodonium salts and sulfonium salts, particularly diaryl iodonium and triaryl sulfonium salt compounds are extremely excellent in terms of both sensitivity and storage stability. Acids and / or radicals can be generated, and these can be used properly by appropriately selecting the use conditions according to the purpose. Specific examples include the following compounds.

(6) Organic peroxide When an organic peroxide type initiator compound is used, radicals can be generated as active species with very high sensitivity.

The organic peroxide used in the present invention includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples thereof include methyl ethyl ketone peroxide, cyclohexanone peroxide, 3, 3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxide Oxy) cyclohexane, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paraffin hydroperoxide, 2,5-dimethylhexane 2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, bis (t-butylperoxide Oxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, acetyl peroxide , Isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, succinic peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, Meta-toluoyl peroxide, diisopropyl par Xydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, t-butyl Peroxyacetate, t-butylperoxypivalate, t-butylperoxyneodecanoate, t-butylperoxyoctanoate, t-butylperoxy-3,5,5-trimethylhexanoate, t- Butyl peroxylaurate, t-butyl peroxybenzoate, di-t-butyl peroxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butyl maleate, t -Butyl peroxyisopropyl carbonate, 3 , 3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3 ′, 4, 4′-tetra (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-octylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (cumylperoxy) Carbonyl) benzophenone, 3,3 ′, 4,4′-tetra (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogendiphthalate), carbonyldi (t-hexylperoxydihydrogen) Diphthalate).

Among these, 3,3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (t-amylperoxycarbonyl) benzophenone, 3 , 3 ′, 4,4′-tetra (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-octylperoxycarbonyl) benzophenone, 3,3 ′, 4,4 ′ -Tetra (cumylperoxycarbonyl) benzophenone, 3,3 ',
Peroxide esters such as 4,4′-tetra (p-isopropylcumylperoxycarbonyl) benzophenone and di-t-butyldiperoxyisophthalate are preferred.
Preferable examples of the initiator compound include titanocene compounds, triazine compounds, and hexaarylbiimidazole compounds, and particularly preferable initiator compounds include hexaarylbiimidazole compounds.

  The initiator compound described above can also be subjected to various chemical modifications for improving the characteristics of the photosensitive layer as in the case of the sensitizing dye. For example, bonding with sensitizing dyes, addition-polymerizable unsaturated compounds and other initiator compound parts, introduction of hydrophilic sites, compatibility improvement, introduction of substituents for suppressing crystal precipitation, substituents for improving adhesion Methods such as introduction and polymerization can be used.

The method of using these initiator compounds can be arbitrarily set as appropriate depending on the performance design of the light-sensitive material as in the case of the sensitizing dye described above. For example, the compatibility with the photosensitive layer can be enhanced by using two or more kinds in combination.
A larger amount of the initiator compound is usually advantageous in terms of photosensitivity, and is used in a range of 0.5 to 80 parts by weight, preferably 1 to 50 parts by weight, with respect to 100 parts by weight of the photosensitive layer component. Sufficient photosensitivity can be obtained.

(C) Polymerizable compound The third essential component “(C) polymerizable compound that reacts with at least one of radical, acid or base” in the photosensitive composition of the present invention is generated by the above-mentioned photoinitiated photoreaction. In addition, the physical or chemical properties of the active species change irreversibly due to the action of the active species, resulting in a curing reaction, color development, decoloring reaction, etc. Any compound can be used, and for example, the compounds listed in the above-mentioned starting system often have such properties.
As the characteristics of the polymerizable compound (C) that changes depending on radicals, acids, and / or bases generated from the photoinitiating system, for example, molecular properties such as absorption spectrum (color), chemical structure, polarizability, It includes changes in material properties such as solubility, strength, refractive index, fluidity, and adhesiveness.

  For example, if a compound whose absorption spectrum changes with pH, such as a pH indicator, is used as the component (C) polymerizable compound and an acid or base is generated from the initiation system, the color tone can be changed only in the exposed area. Such a composition is useful as an image forming material. Similarly, when a compound whose absorption spectrum is changed by oxidation / reduction or nucleophilic addition reaction is used as the polymerizable compound (C), it is possible to form an image by causing oxidation or reduction by radicals generated from the initiation system. . Such examples include, for example, J. Am. Chem. Soc., 108, 128 (1986), J. Imaging. Soc., 30, 215 (1986), Israel. J. Chem., 25, 264. (1986).

  Among these, a photocurable resin or a negative photopolymer can be formed by using a compound capable of addition polymerization or polycondensation as the polymerizable compound (C) and combining it with an initiation system. Such a composition is also useful as a negative photosensitive layer of a lithographic printing plate precursor.

  Examples of such polymerizable compound (C) include radical polymerizable compounds (such as compounds having an ethylenically unsaturated bond), cationic polymerizable compounds (such as epoxy compounds, vinyl ether compounds, and methylol compounds), and anionic polymerizable compounds (such as epoxy). Examples of such compounds are described in, for example, Photopolymer Social Association, Photopolymer Handbook, Kogyo Kenkyukai (1989), Polymer, Vol. 45, 786 (1996), etc. . In addition, a composition in which a thiol compound is used as the polymerizable compound (C) and combined with a photoradical generation system is also well known.

  (C) It is also useful to use an acid-decomposable compound as the polymerizable compound and combine it with a photoacid generator. For example, a material that uses a polymer whose side chain or main chain is decomposed by an acid and changes its solubility or hydrophilicity / hydrophobicity by light is widely used as a photodegradable photosensitive resin or a positive photopolymer. Such specific examples are, for example, ACS.Symp.Ser.242,11 (1984), JP-A-60-3625, U.S. Pat. Nos. 5102771, 5206317, 5212047, JP 4-26850, JP-A-3-1921731, JP-A-60-10247, JP-A-62-245050 and the like.

  For the purpose of obtaining a highly sensitive lithographic printing plate precursor, which is one of the main uses of the photosensitive composition of the present invention, an addition polymerizable compound (C) which is a polymerizable compound is used below. Take this case as an example and explain in more detail.

(C-1) Addition polymerizable compound The addition polymerizable compound having at least one ethylenically unsaturated double bond, which is a preferred polymerizable compound (C) used in the present invention, has a terminal ethylenically unsaturated bond. It is selected from compounds having at least 1, preferably 2 or more. Such compound groups are widely known in the industrial field, and these can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), and esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, unsaturated carboxylic acid ester having a nucleophilic substituent such as hydroxyl group, amino group, mercapto group, amide and monofunctional or polyfunctional isocyanate, addition reaction product of epoxy, monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. In addition, an unsaturated carboxylic acid ester having an electrophilic substituent such as an isocyanato group or an epoxy group, an addition reaction product of an amide with a monofunctional or polyfunctional alcohol, an amine or a thiol, a halogen group Also suitable are substitution reaction products of unsaturated carboxylic acid esters, amides with monofunctional or polyfunctional alcohols, amines, and thiols having a leaving substituent such as a tosyloxy group. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy- 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.

Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.
Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, Those having an aromatic skeleton described in JP-A-59-5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.
The aforementioned ester monomers can also be used as a mixture.

Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.
Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.

  In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinyl urethane containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula (V) to a polyisocyanate compound having two or more isocyanate groups. Compounds and the like.

_{CH 2 = C (R) COOCH} 2 CH (R ') OH (V)
(However, R and R ′ represent H or CH _3. )

  Further, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56-17654 Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable.

  Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, JP-A-1-105238 Can obtain a photosensitive composition having a very high photosensitive speed.

  Other examples include reacting polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490. And polyfunctional acrylates and methacrylates such as epoxy acrylates. Further, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-B-1-40336, and vinylphosphonic acid compounds described in JP-A-2-25493 are also included. be able to. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Journal of Japan Adhesion Association vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

About these addition polymerizable compounds, the details of usage, such as the structure, single use or combination, addition amount, etc. can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example,
It is selected from the following viewpoints. From the viewpoint of photosensitive speed, a structure having a high unsaturated group content per molecule is preferable. Further, in order to increase the strength of the image portion, that is, the cured film, those having three or more functionalities are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrene compound, vinyl ether type). A method of adjusting both photosensitivity and intensity by using a compound) is also effective. A compound having a large molecular weight or a compound having high hydrophobicity is excellent in photosensitive speed and film strength, but is not preferable in terms of development speed and precipitation in a developer. Further, the selection and use method of the addition polymerization compound is also an important factor for the compatibility and dispersibility with other components (for example, binder polymer, initiator, colorant, etc.) in the photosensitive layer. The compatibility may be improved by using a low-purity compound or using two or more kinds in combination. In addition, a specific structure may be selected for the purpose of improving the adhesion of the substrate and an overcoat layer described later. As for the compounding ratio of the addition polymerizable compound in the photosensitive layer, a larger amount is advantageous in terms of sensitivity, but if it is too much, an undesirable phase separation occurs or a problem in the production process due to the adhesiveness of the photosensitive layer. For example, problems such as transfer of photosensitive layer components and manufacturing defects due to adhesion, and precipitation from the developer may occur. From these viewpoints, the addition polymerizable compound is preferably used in the range of 5 to 80% by mass, and more preferably 25 to 75% by mass with respect to the nonvolatile component in the photosensitive layer. These may be used alone or in combination of two or more. In addition, the use method of the addition polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface adhesiveness, etc. Depending on the case, a layer configuration and coating method such as undercoating and overcoating can be performed.

  (C) The content in the case of using a compound other than the (C-1) addition polymerizable compound as the polymerizable compound can be appropriately selected as appropriate depending on the intended property change or the compound used. Specifically, when a compound whose absorption spectrum is changed by oxidation / reduction or nucleophilic addition reaction is used, it is preferably about 10 to 80% by mass in the total solid content of the composition.

(D) Binder polymer In application to the photosensitive layer of a lithographic printing plate precursor which is a preferred embodiment of the photosensitive composition of the present invention, a binder polymer is further used in the photosensitive composition from the viewpoint of improving film properties. It is preferable to do.
As the binder polymer, it is preferable to contain a linear organic polymer. As such a “linear organic polymer”, any compound may be used, but preferably water or weak alkaline water soluble or swellable to enable water development or weak alkaline water development. A linear organic polymer is selected. The linear organic high molecular polymer is selected and used not only as a film-forming agent for the composition but also according to its use as water, weak alkaline water or an organic solvent developer. For example, when a water-soluble organic polymer is used, water development is possible. Examples of such linear organic high molecular polymers include addition polymers having a carboxylic acid group in the side chain, such as JP 59-44615, JP-B 54-34327, JP-B 58-12777, and JP-B. 54-25957, JP-A-54-92723, JP-A-59-53836, JP-A-59-71048, ie, methacrylic acid copolymer, acrylic acid copolymer , Itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, and partially esterified maleic acid copolymer. Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group are useful.

Among these, [benzyl (meth) acrylate / (meth) acrylic acid / other addition polymerizable vinyl monomers as required] copolymer and [allyl (meth) acrylate / (meth) acrylic acid / as required Other addition-polymerizable vinyl monomers] are preferred because they are excellent in the balance of film strength, sensitivity and developability.
In addition, Japanese Patent Publication No.7-12004, Japanese Patent Publication No.7-120041, Japanese Patent Publication No.7-120042
No. 8, JP-B-8-12424, JP-A-63-287944, JP-A-63-287947, JP-A-1-271774, JP-A-10-116232, etc. Since the urethane-based binder polymer containing a group is very excellent in strength, it is advantageous in terms of printing durability and suitability for low exposure.
A binder having an amide group described in JP-A No. 11-171907 is suitable because it has excellent developability and film strength.

  In addition, polyvinyl pyrrolidone, polyethylene oxide, and the like are useful as the water-soluble linear organic polymer. In order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful. These linear organic high molecular polymers can be mixed in an arbitrary amount in the entire composition. However, when it exceeds 90% by mass, a preferable result is not given in terms of the strength of the formed image. Preferably it is 30-85 mass%. The photopolymerizable compound having an ethylenically unsaturated double bond and the linear organic high molecular weight polymer are preferably in the range of 1/9 to 7/3 by mass ratio. In a preferred embodiment, a binder polymer that does not require water and is soluble in alkali is used. By doing so, an organic solvent that is not environmentally preferable is not used as the developer, or the amount can be limited to a very small amount. In such a method of use, the acid value of the binder polymer (the acid content per gram of polymer expressed as a chemical equivalent number) and the molecular weight are appropriately selected from the viewpoint of image strength and developability. The preferred acid value is 0.4 to 3.0 meq / g, and the preferred molecular weight is in the range of 3000 to 500,000 in terms of mass average molecular weight, more preferably the acid value is 0.6 to 2.0 and the molecular weight is It is in the range of 10,000 to 300,000.

(E) Other components The photosensitive composition of the present invention may further contain other components suitable for its use and production method. Hereinafter, preferred additives will be exemplified.
(E-1) Co-sensitizer The sensitivity can be further improved by using a certain additive (hereinafter referred to as a co-sensitizer). These mechanisms of action are not clear, but many are thought to be based on the following chemical processes. That is, the photosensitivity initiated by the thermal polymerization initiator and the subsequent intermediate polymerization species (radicals and cations) generated in the course of the addition polymerization reaction react with the co-sensitizer to generate new active radicals. Presumed to be. These can be broadly divided into (a) those that can be reduced to generate active radicals, (b) those that can be oxidized to generate active radicals, and (c) radicals that are more active by reacting with less active radicals. Can be classified into those that act as chain transfer agents, but there is often no generality as to which of these individual compounds belong.

(A) Compound that is reduced to produce an active radical Compound having a carbon-halogen bond: It is considered that the carbon-halogen bond is reductively cleaved to generate an active radical. Specifically, for example, trihalomethyl-s-triazines and trihalomethyloxadiazoles can be preferably used.
Compound having nitrogen-nitrogen bond: It is considered that the nitrogen-nitrogen bond is reductively cleaved to generate an active radical. Specifically, hexaarylbiimidazoles and the like are preferably used.
Compound having oxygen-oxygen bond: It is considered that an oxygen-oxygen bond is reductively cleaved to generate an active radical. Specifically, for example, organic peroxides are preferably used.
Onium compounds: It is considered that carbon-hetero bonds and oxygen-nitrogen bonds are reductively cleaved to generate active radicals. Specifically, for example, diaryliodonium salts, triarylsulfonium salts, N-alkoxypyridinium (azinium) salts and the like are preferably used.
Ferrocene and iron arene complexes: An active radical can be reductively generated.

(B) Compound which is oxidized to generate an active radical Alkylate complex: It is considered that a carbon-hetero bond is oxidatively cleaved to generate an active radical. Specifically, for example, triarylalkyl borates are preferably used.
Alkylamine compound: It is considered that the C—X bond on carbon adjacent to nitrogen is cleaved by oxidation to generate an active radical. X is preferably a hydrogen atom, a carboxyl group, a trimethylsilyl group, a benzyl group or the like. Specific examples include ethanolamines, N-phenylglycines, N-trimethylsilylmethylanilines, and the like.
Sulfur-containing and tin-containing compounds: Compounds in which the nitrogen atoms of the above-described amines are replaced with sulfur atoms and tin atoms can generate active radicals by the same action. Further, a compound having an SS bond is also known to be sensitized by SS cleavage.

α-Substituted methylcarbonyl compound: An active radical can be generated by oxidative cleavage of the carbonyl-α carbon bond. Moreover, what converted carbonyl into the oxime ether also shows the same effect | action. Specifically, 2-alkyl-1- [4- (alkylthio) phenyl] -2-morpholinopronone-1 and these and a hydroxylamine were reacted, and then N—OH was etherified. Oxime ethers can be listed.
Sulfinic acid salts: An active radical can be reductively generated. Specific examples include arylsulfin sodium.

(C) Compounds that react with radicals to convert into highly active radicals or act as chain transfer agents: For example, compounds having SH, PH, SiH, and GeH in the molecule are used. These can generate hydrogen by donating hydrogen to a low-activity radical species to generate radicals, or after being oxidized and deprotonated. Specific examples include 2-mercaptobenzthiazoles, 2-mercaptobenzoxazoles, 2-mercaptobenzimidazoles and the like.

  More specific examples of these co-sensitizers are described, for example, in JP-A-9-236913 as additives for the purpose of improving sensitivity, and these are also applied in the present invention. be able to. Some examples are shown below, but the present invention is not limited thereto. In the following formulae, -TMS represents a trimethylsilyl group.

These co-sensitizers can also be subjected to various chemical modifications for improving the characteristics of the photosensitive layer as in the case of the above sensitizing dye. For example, bonds with sensitizing dyes, initiator compounds, addition polymerizable unsaturated compounds and other parts, introduction of hydrophilic sites, compatibility improvement, introduction of substituents to suppress crystal precipitation, substituents that improve adhesion Methods such as introduction and polymerization can be used.
These co-sensitizers can be used alone or in combination of two or more. The amount used is 0.05 to 100 parts by weight, preferably 1 to 80 parts by weight, and more preferably 3 to 50 parts by weight with respect to 100 parts by weight of the compound having an ethylenically unsaturated double bond.

(E-2) Polymerization inhibitor In the present invention, in addition to the above basic components, unnecessary thermal polymerization of a compound having an ethylenically unsaturated double bond that can be polymerized during production or storage of the photosensitive composition. In order to prevent this, it is desirable to add a small amount of a thermal polymerization inhibitor. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol ), 2,2'-methylenebis (4-methyl-6-t-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the mass of the entire composition. If necessary, add a higher fatty acid derivative such as behenic acid or behenic acid amide to prevent polymerization inhibition due to oxygen, and use it as a lithographic printing plate precursor. In this process, it may be unevenly distributed on the surface of the photosensitive layer. The amount of the higher fatty acid derivative added is preferably about 0.5% by mass to about 10% by mass of the total composition.

(E-3) Colorant, etc. Furthermore, when the photosensitive composition of the present invention is used for a lithographic printing plate precursor, a dye or pigment may be added for the purpose of coloring the photosensitive layer. Thereby, so-called plate inspection properties such as visibility after plate making and suitability for an image density measuring machine as a printing plate can be improved. As a colorant, many dyes cause a decrease in the sensitivity of the photosensitive layer. Therefore, it is particularly preferable to use a pigment as the colorant. Specific examples include pigments such as phthalocyanine pigments, azo pigments, carbon black and titanium oxide, and dyes such as ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. The addition amount of the dye and the pigment is preferably about 0.5% by mass to about 5% by mass of the total composition.

(E-4) Other additives Further, when the photosensitive composition of the present invention is used for a lithographic printing plate precursor, an inorganic filler, other plasticizers, and ink on the surface of the photosensitive layer are used to improve the physical properties of the cured film. You may add well-known additives, such as a fat-sensitizing agent which can improve the inking property.

  Examples of plasticizers include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, and triacetyl glycerin. 10 mass% or less can be added with respect to the total mass of the compound which has an ionic unsaturated double bond, and a binder.

Further, for the purpose of improving the film strength (printing durability) described later, a UV initiator, a mature crosslinking agent, or the like can be added to enhance the effect of heating and exposure after development.
In addition, it is also possible to provide an additive and an intermediate layer for improving the adhesion between the photosensitive layer and the support and improving the development and removal of the unexposed photosensitive layer. For example, by adding or undercoating a compound having a relatively strong interaction with the substrate, such as a compound having a diazonium structure or a phosphone compound, adhesion can be improved and printing durability can be improved. By adding or undercoating a hydrophilic polymer such as acid or polysulfonic acid, the developability of the non-image area is improved, and the stain resistance can be improved.

  In order to produce a lithographic printing plate precursor, when the photosensitive composition of the present invention is applied on a support to form a photosensitive layer, it is dissolved in various organic solvents and used. Solvents used here include acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, methyl lactate, lactic acid There are ethyl and the like. These solvents can be used alone or in combination. The solid content in the coating solution is suitably 2 to 50% by mass.

The coating amount of the photosensitive layer on the support is preferably selected as appropriate according to the use in consideration of the sensitivity of the photosensitive layer, the developability, the strength of the exposed film and the printing durability. If the amount applied is too small,
Printing durability is not sufficient. On the other hand, if the amount is too large, the sensitivity is lowered, it takes time for exposure, and a longer time is required for development processing, which is not preferable. The coating amount as the photosensitive layer of the lithographic printing plate precursor for scanning exposure, which is a preferred use mode of the photosensitive composition of the present invention, is generally about 0.1 g / m ² to about 10 g / m in terms of the mass after drying. A range of m ² is suitable. More preferably from 0.5 to 5 g / m ^2.

  When the photosensitive composition of the present invention is used as a photosensitive layer of a lithographic printing plate precursor, it is represented by the general formula (1) or the general formula (2) as a sensitizing dye from the viewpoint of sensitivity and storage stability. And an initiator system in which a titanocene compound or a hexaarylbiimidazole compound is combined as an initiator compound, an initiator system in which a hexaarylbiimidazole compound is combined is more preferable, and an initiator system comprising these and (C-1) An embodiment containing an addition polymerizable compound is particularly preferable.

(Support)
In order to obtain a lithographic printing plate precursor using the photosensitive composition of the present invention, it is desirable to provide the photosensitive layer on a support having a hydrophilic surface. As the hydrophilic support, a conventionally known hydrophilic support used in a lithographic printing plate can be used without limitation. The support used is preferably a dimensionally stable plate, for example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc). , Copper, etc.), plastic films (for example, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.) It is done. These may be a single component sheet such as a resin film or a metal plate, or may be a laminate of two or more materials. For example, a paper or plastic film on which a metal as described above is laminated or vapor-deposited. And laminated sheets of different plastic films. Also, these surfaces may be subjected to appropriate known physical and chemical treatments for the purpose of imparting hydrophilicity and improving strength, if necessary.

  Particularly preferred supports include paper, polyester film or aluminum plate, among which dimensional stability is good and relatively inexpensive, and a surface with excellent hydrophilicity and strength can be provided by surface treatment as required. An aluminum plate is particularly preferred. A composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 is also preferable.

  A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is at most 10% by mass. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, particularly preferably 0.2 mm to 0.3 mm.

In the case of a support having a surface of metal, particularly aluminum, roughening (graining) treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluoride zirconate, phosphate, etc., or anodic oxidation treatment, etc. It is preferable that surface treatment is performed.
Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired.
The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used.
The aluminum plate roughened in this way can be subjected to an anodizing treatment to enhance the water retention and wear resistance of the surface through an alkali etching treatment and a neutralization treatment, if desired. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.

Furthermore, an aluminum plate that has been roughened and then immersed in an aqueous sodium silicate solution can be preferably used. As described in Japanese Patent Publication No. 47-5125, an aluminum plate is anodized and then immersed in an aqueous solution of an alkali metal silicate is preferably used. The anodizing treatment is carried out in an electrolytic solution in which an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid or boric acid, or an organic acid such as oxalic acid or sulfamic acid, or a salt solution thereof, or a combination of two or more thereof, is used. This is carried out by passing an electric current using the aluminum plate as an anode.
Silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective as a hydrophilic treatment for the support. A support body provided with electrolytic grains as disclosed in JP-B-46-27481, JP-A-52-58602, JP-A-52-30503, and the above-mentioned anodizing treatment and sodium silicate treatment. A combined surface treatment is also useful. Further, those obtained by sequentially performing mechanical surface roughening, chemical etching, electrolytic graining, anodizing treatment and sodium silicate treatment as disclosed in JP-A-56-28893 are also suitable.

Furthermore, after performing these treatments, water-soluble resins such as polyvinylphosphonic acid, polymers and copolymers having sulfonic acid groups in the side chain, polyacrylic acid, water-soluble metal salts (for example, zinc borate) or Those having a primer such as a yellow dye or an amine salt are also suitable.
Further, a sol-gel treated substrate in which a functional group capable of causing an addition reaction by a radical as disclosed in JP-A-7-159983 is covalently used.
As another preferred example, a substrate provided with a water-resistant hydrophilic layer as a surface layer on an arbitrary support can be raised. Examples of such a surface layer include a layer composed of an inorganic pigment and a binder described in US Pat. No. 3,055,295 and JP-A-56-13168, and a hydrophilic swelling described in JP-A-9-80744. Examples thereof include sol-gel films made of titanium oxide, polyvinyl alcohol, and silicic acids described in JP-A-8-507727.
These hydrophilic treatments are performed to make the surface of the support hydrophilic, in order to prevent harmful reactions of the photosensitive composition provided thereon, and to improve the adhesion of the photosensitive layer, etc. It is for the purpose.

(Protective layer)
When the photosensitive composition of the present invention is used in a lithographic printing plate precursor for scanning exposure, a protective layer can be provided on the photosensitive layer containing a polymerizable compound as necessary. Such a lithographic printing plate precursor is usually exposed in the air, but the protective layer is a low molecular weight molecule such as oxygen or a basic substance present in the air that inhibits the image forming reaction caused by exposure in the photosensitive layer. This prevents the compound from being mixed into the photosensitive layer, and prevents the inhibition of the image forming reaction due to exposure in the air. Therefore, the properties desired for such a protective layer are low permeability of low-molecular compounds such as oxygen, furthermore, good transparency of light used for exposure, excellent adhesion to the photosensitive layer, And it is desirable that it can be easily removed in the development process after exposure.

  Such a device for the protective layer has been conventionally devised, and is described in detail in US Pat. No. 3,458,311 and JP-A-55-49729. As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, Water-soluble polymers such as acrylic acid are known, but among these, using polyvinyl alcohol as a main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. In particular, a mixture obtained by replacing polyvinyl pyrrolidone in a range of 15 to 50% by mass with respect to polyvinyl alcohol is preferable from the viewpoint of storage stability.

  Specific examples of polyvinyl alcohol include those having a hydrolysis rate of 71 to 100% and a molecular weight in the range of 300 to 2400. Specifically, PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, manufactured by Kuraray Co., Ltd. PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA- 420, PVA-613, L-8 and the like.

  Components of the protective layer (selection of PVA, use of additives), coating amount, and the like are selected in consideration of fogging, adhesion, and scratch resistance in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of the PVA used (the higher the content of the unsubstituted vinyl alcohol unit in the protective layer), the thicker the film thickness, the higher the oxygen barrier property, which is advantageous in terms of sensitivity. However, when the oxygen barrier property is extremely increased, there arises a problem that unnecessary polymerization reaction occurs during production and raw storage, and unnecessary fogging and image line thickening occur during image exposure. In addition, adhesion to the image area and scratch resistance are extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on a new oil-based polymer layer, film peeling due to insufficient adhesion tends to occur, and the peeled part causes defects such as poor film hardening due to inhibition of oxygen polymerization.

  On the other hand, various proposals have been made to improve the adhesion between these two layers. For example, 20 to 60% by mass of acrylic emulsion or water-insoluble vinylpyrrolidone-vinyl acetate copolymer is mixed in a hydrophilic polymer made of polyvinyl alcohol and laminated on the photosensitive layer, thereby providing sufficient adhesion. It is described that it is obtained. Any of these known techniques can be applied to the protective layer in the present invention. Such a coating method for the protective layer is described in detail in, for example, US Pat. No. 3,458,311 and JP-A-55-49729.

  Furthermore, other functions can be imparted to the protective layer. For example, by adding a colorant (such as a water-soluble dye) that is excellent in transparency of light used for exposure (for example, a wavelength of 760 to 1200 nm for an infrared laser) and can efficiently absorb light of a wavelength that is not related to exposure. Therefore, the suitability for safelight can be further enhanced without lowering the sensitivity.

  When a lithographic printing plate precursor using the photosensitive composition of the present invention is made into a lithographic printing plate, it is usually subjected to an exposure process (image exposure) described in detail below, and then a photosensitive layer with a developer. The unexposed portion is removed to form an image. As a preferred developer when these photosensitive compositions are used for preparing a lithographic printing plate, a developer as described in JP-B-57-7427 is exemplified, and sodium silicate and potassium silicate are used. , Sodium hydroxide, potassium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic ammonium phosphate, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, aqueous ammonia etc. A suitable inorganic alkaline agent or an aqueous solution of an organic alkaline agent such as monoethanolamine or diethanolamine is suitable. It is added so that the concentration of such an alkaline solution is 0.1 to 10% by mass, preferably 0.5 to 5% by mass.

Such an alkaline aqueous solution may contain a small amount of a surfactant, an organic solvent such as benzyl alcohol, 2-phenoxyethanol, and 2-butoxyethanol as necessary. Examples thereof include those described in US Pat. Nos. 3,375,171 and 3,615,480.
Further, the developers described in JP-A-50-26601, 58-54341, JP-B-56-39464, and 56-42860 are also excellent.

  As a particularly preferred developer used here, a nonionic compound described in JP-A No. 2002-202616 is contained, the pH is 11.5 to 12.8, and the conductivity is 3 to 30 mS / cm. And a developer having

  In the plate-making process of the lithographic printing plate precursor according to the present invention, the entire surface may be heated before exposure, during exposure, and between exposure and development, if necessary. By such heating, the image forming reaction in the photosensitive layer is promoted, and advantages such as improvement in sensitivity and printing durability and stabilization of sensitivity may occur. Further, for the purpose of improving the image strength and printing durability, it is also effective to carry out whole surface post-heating or whole surface exposure on the developed image. Usually, heating before development is preferably performed under mild conditions of 150 ° C. or less. If the temperature is too high, problems such as an undesired curing reaction in the non-image area may occur. On the other hand, very strong conditions can be used for heating after development. Usually, a heat treatment in the range of 200 to 500 ° C. is performed. If the temperature is low, sufficient image strengthening action cannot be obtained. If the temperature is too high, problems such as deterioration of the support and thermal decomposition of the image area occur.

  As a method for exposing the lithographic printing plate precursor for scanning exposure according to the present invention, a known method can be used without limitation. Desirably, the wavelength of the light source is 350 nm to 450 nm, and specifically, an InGaN-based semiconductor laser is suitable. The exposure mechanism may be any of an internal drum system, an external drum system, a flat bed system, and the like. In addition, the photosensitive layer component of the present invention can be made soluble in neutral water or weak alkaline water by using a high water-soluble component. After loading on top, a system such as exposure-development can be performed on the machine.

As an available laser light source of 350 to 450 nm, the following can be used.
As a gas laser, Ar ion laser (364 nm, 351 nm, 10 mW to 1 W), Kr ion laser (356 nm, 351 nm, 10 mW to 1 W), He—Cd laser (441 nm, 32
5 nm, 1 mW to 100 mW), Nd: YAG (YVO ₄ ) and SHG crystal as a solid state laser
Two combinations (355 nm, 5 mW to 1 W), a combination of Cr: LiSAF and SHG crystal (430 nm, 10 mW), a semiconductor laser system, a KNbO ₃ ring resonator (430 nm,
30 mW), a combination of waveguide type wavelength conversion element and AlGaAs, InGaAs semiconductor (380 nm to 450 nm, 5 mW to 100 mW), a combination of waveguide type wavelength conversion element and AlGaInP, AlGaAs semiconductor (300 nm to 350 nm, 5 mW to 100 mW), AlGaInN (350 nm to 450 nm, 5 mW to 30 mW) In addition, N ₂ laser (337 nm, pulse 0.1 to 10 mJ), XeF (351 nm, pulse 10 to 250 mJ), etc. can be used as the pulse laser.
In particular, an AlGaInN semiconductor laser (commercially available InGaN-based semiconductor laser 400 to 410 nm, 5 to 30 mW) is preferable in terms of wavelength characteristics and cost.

Further, as a lithographic printing plate exposure apparatus of a scanning exposure method, there are an inner drum method, an outer drum method, and a flat bed method as an exposure mechanism, and all of the light sources other than the pulse laser can be used as a light source. . Practically, the following exposure apparatus is particularly preferable in terms of the relationship between the photosensitive material sensitivity and the plate making time.
・ Single beam exposure system that uses one gas laser or solid-state laser light source with internal drum system ・ Multi-beam exposure system that uses many (10 or more) semiconductor lasers with flat bed system ・ Many semiconductor lasers with external drum system ( Multi-beam exposure equipment used (10 or more)

In the laser direct drawing type lithographic printing plate as described above, the photosensitive material sensitivity X (J / cm ² ) is generally used.
The equation (eq1) is established among the exposure area S (cm ² ) of the photosensitive material, the power q (W) of one laser light source, the number of lasers n, and the total exposure time t (s).
X · S = n · q · t (eq1)

i) In the case of the internal drum (single beam) system, the laser rotation speed f (radians / s), the sub-scanning length Lx (cm) of the photosensitive material, the resolution Z (dots / cm), and the total exposure time t (s) In general, equation (eq2) holds.
f · Z · t = Lx (eq2)
ii) In the case of the external drum (multi-beam) system, the drum rotation speed F (radians / s), the photosensitive material sub-scanning length Lx (cm), the resolution Z (dots / cm), the total exposure time t (s), the number of beams In general, equation (eq3) is established during (n).
F.Z.n.t = Lx (eq3)
iii) In the case of a flat bed (multi-beam) method, the rotational speed H (radian / s) of the polygon mirror, the sub-scanning length Lx (cm) of the photosensitive material, the resolution Z (dot / cm), the total exposure time t (s), Equation (eq4) is generally established between the number of beams (n).
H.Z.n.t = Lx (eq4)

The resolution (2560 dpi) required for the actual printing plate, plate size (A1 / B1, sub-scan length 42 inch), exposure conditions of about 20 sheets / hour and the photosensitive characteristics (photosensitive wavelength, By substituting (sensitivity: about 0.1 mJ / cm ² ) into the above equation, it can be understood that a combination with a multi-beam exposure method of a semiconductor laser is more preferable in the photosensitive material of the present invention. Further, by combining operability, cost, etc., a combination with an external drum type semiconductor laser multi-beam exposure apparatus is most preferable.

  In addition, as other exposure light rays for the photosensitive composition of the present invention, ultrahigh pressure, high pressure, medium pressure, and low pressure mercury lamps, chemical lamps, carbon arc lamps, xenon lamps, metal halide lamps, various visible and ultraviolet laser lamps Fluorescent lamps, tungsten lamps, sunlight, etc. can also be used.

  Applications of the photosensitive composition according to the present invention can be applied without limitation to a wide range of fields known as applications of photocurable resins in addition to the photosensitive layer of the lithographic printing plate precursor for scanning exposure described in detail above. For example, a highly sensitive optical modeling material can be obtained by applying to a liquid photosensitive composition used in combination with a cationically polymerizable compound as necessary. Further, a hologram material can be obtained by utilizing a change in refractive index accompanying photopolymerization. It can be applied to various transfer materials (peeling sensitive material, toner developing sensitive material, etc.) by utilizing the change in surface tackiness due to photopolymerization. It can also be applied to photocuring of microcapsules. It can also be applied to the production of electronic materials such as photoresists, and photocurable resin materials such as inks, paints and adhesives.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
<Synthesis Examples 1-2>
(Synthesis Example 1: Synthesis of Exemplified Compound D1)
After dissolving 1.8 g of diethylaminobenzaldehyde, 0.7 g of piperidine and 2.1 g of 3-ethyl-2-cyclohexylimino-oxazolidine-4-one in 50 ml of ethanol, the mixture was stirred for 8 hours while refluxing. After completion of the reaction, the mixture was allowed to cool to room temperature, whereby yellow crystals were precipitated. The precipitated crystals were filtered, added to 50 ml of methanol, and stirred for 1 hour. The crystals were filtered and dried to obtain 1.4 g of the following exemplary compound (D1) (yield 38%). Identification was performed by ¹ H-NMR (solvent CDCl ₃ ), infrared absorption spectrum, mass spectrometry spectrum, and elemental analysis. Electronic absorption spectrum (THF): absorption maximum wavelength 385 nm, absorption maximum molar extinction coefficient 37200.

(Synthesis Example 2: Synthesis of Exemplified Compound D7)
17.7 g of diethylaminobenzaldehyde and 1.0 g of piperidine were dissolved in 250 ml of methanol and stirred for 1 hour while refluxing. Next, 19.9 g of 3-cyclohexyl-2-thioxo-4-oxazolidione was added and stirred while refluxing for 4 hours. After completion of the reaction, the reaction mixture was allowed to cool to room temperature to precipitate orange crystals. The precipitated crystals were filtered, added to 500 ml of methanol, and stirred for 1 hour. The crystals were filtered and dried to obtain 30.4 g of the following compound (D7 ′) as a dye precursor (yield 85%). Identification was performed by ¹ H-NMR.

Next, after 1.7 g of silver nitrate was dissolved in 20 ml of acetonitrile, 1.8 g of the above compound (D7 ′) as a dye precursor was added and stirred at room temperature for 0.5 hour. Next, 1.0 g of cyclohexylamine was added dropwise and stirred for 1.5 hours, then 1.0 g of triethylamine was added dropwise, and the mixture was further stirred for 1.5 hours. After completion of the reaction, 30 ml of acetone was added, the precipitated silver salt was filtered off using celite, and the filtrate was poured into 150 ml of water. The precipitated crystals were collected by filtration and reslurried in methanol to obtain 1.9 g of the following exemplary compound (D7) (yield 88%). ¹ H-NMR (
Identification was carried out by solvent CDCl ₃ ), infrared absorption spectrum, mass spectrometry spectrum, and elemental analysis. Electronic absorption spectrum (THF): absorption maximum wavelength 384 nm, absorption maximum molar extinction coefficient 38300.

<Examples 1-16, Comparative Examples 1-7>
(Preparation of support)
An aluminum plate having a thickness of 0.3 mm was etched by being immersed in 10% by mass sodium hydroxide at 60 ° C. for 25 seconds, washed with running water, neutralized with 20% by mass nitric acid, and then washed with water. This was subjected to an electrolytic surface roughening treatment in a 1% by mass nitric acid aqueous solution using a sinusoidal alternating waveform current at an anode time electricity of 300 coulomb / dm ² . Subsequently, after dipping in a 1% by mass aqueous sodium hydroxide solution at 40 ° C. for 5 seconds and then in a 30% by mass sulfuric acid aqueous solution and desmutting at 60 ° C. for 40 seconds, the current density in a 20% by mass sulfuric acid aqueous solution was 2A / current density. At dm ² , the anodization treatment was performed for 2 minutes so that the thickness of the anodized film was 2.7 g / m ² . When the surface roughness was measured, it was 0.3 μm (Ra indication according to JISB0601).

The following sol-gel reaction liquid was applied to the back surface of the substrate thus treated with a bar coater, dried at 100 ° C. for 1 minute, and a support provided with a backcoat layer having a coating amount after drying of 70 mg / m ^2. It was created.

(Sol-gel reaction solution)
Tetraethylsilicate 50 parts by weight Water 20 parts by weight Methanol 15 parts by weight Phosphoric acid 0.05 parts by weight

  When the above components were mixed and stirred, heat generation started in about 5 minutes. After reacting for 60 minutes, a backcoat coating solution was prepared by adding the following solution.

Pyrogallol formaldehyde condensation resin (molecular weight 2000) 4 parts by weight Dimethyl phthalate 5 parts by weight Fluorosurfactant 0.7 parts by weight (N-butylperfluorooctane / sulfonamidoethyl acrylate / polyoxyethylene acrylate copolymer: molecular weight 20,000)
Methanol silica sol 50 parts by mass (manufactured by Nissan Chemical Industries, Ltd., methanol 30% by mass)
800 parts by mass of methanol

(Preparation of photosensitive layer)
On the aluminum support thus treated, a photosensitive composition having the following composition was applied in a dry coating amount of 1.0 to 2.0 g / m ² and dried at 80 ° C. for 2 minutes to form a photosensitive layer. Formed.

(Photosensitive composition)
The following addition polymerizable compound (M-1) 1.5 g
The following polyurethane resin binder (U-1) 2.0g

(U-1)
Polyurethane resin, which is a polycondensation product of the following diisocyanate and diol: 4,4'-diphenylmethane diisoisocyanate (MDI)
・ Hexamethylene diisocyanate (HMDI)
-Polypropylene glycol, mass average molecular weight 1000 (PPG1000)
・ 2,2-bis (hydroxymethyl) propionic acid (DMPA)
・ Glycerin monomethacrylate (Blemmer GLM manufactured by NOF Corporation)
[Copolymerization molar ratio (MDI / HMDI / PPG1000 / DMPA / Blemmer GLM = 80/20/22/52/26)]
Measured acid value obtained by KOH titration 0.92 meq / g
Mass average molecular weight determined by GPC measurement: 60,000 photopolymerization initiation system (compound used, contents are listed in Table 1)
・ Sensitizing dye Xg
・ Initiator Yg
・ Co-sensitizer Zg
Fluorine nonionic surfactant (F-780F) 0.03g
Thermal polymerization inhibitor 0.01g
(N-nitrosophenylhydroxylamine aluminum salt)
2.0 g of pigment dispersion
(Composition of pigment dispersion)
Pigment Blue 15: 6 15 parts by mass Allyl methacrylate / methacrylic acid copolymer 10 parts by mass (copolymerization molar ratio 83/17)
-Cyclohexanone 15 parts by mass-Methoxypropyl acetate 20 parts by mass-Propylene glycol monomethyl ether 40 parts by mass Methyl ethyl ketone 20 g
20g propylene glycol monomethyl ether

(Formation of protective layer)
On this photosensitive layer, a 3% by weight aqueous solution of polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 550) was applied so that the dry coating weight was 2 g / m ^2, and dried at 100 ° C. for 2 minutes for protection. A layer was formed to obtain a lithographic printing plate precursor.

[Sensitivity evaluation]
A Fuji step guide manufactured by Fuji Photo Film Co., Ltd. (gray scale whose transmission optical density changes discontinuously at ΔD = 0.15) was brought into close contact with the lithographic printing plate precursor thus obtained. Exposure was performed with a xenon lamp through a filter so as to obtain a known exposure energy.
Thereafter, the film was immersed in a developer having the following composition at 25 ° C. for 10 seconds, developed, the maximum number of steps at which the image was completely removed was read, the exposure energy amount was determined, and the sensitivity was calculated (unit, mJ / cm). ² ). The smaller the amount of energy, the higher the sensitivity. For the purpose of estimating the suitability of exposure to a short-wave semiconductor laser, Kenko BP-40 was used as an optical filter, and exposure was performed with 400 nm monochromic light. The results are shown in Table 1.

[Evaluation of storage stability]
The same printing plate under the high temperature condition (60 ° C.) as the value X ₀ obtained by measuring the dot area of 50% of the exposure setting on the exposure plate on the printing plate shown in Table 1 measured with the ccDOT manufactured by Centurfax Co., Ltd. After 3 days of storage, laser exposure was performed with exactly the same amount of light as before storage at high temperature, and the difference (X ₀ -X ₃ ) in the dot area value X ₃ of 50% of the drawing setting measured after the development processing was obtained in the same manner. . The smaller this (X ₀ −X ₃ ) value, the better the storage stability, and it can be said that the storage stability is good when it is 5 or less. The results of the storage stability evaluation are also shown in Table 1.

(Developer)
PH 12.0 aqueous solution with the following composition: Potassium hydroxide 0.2g
・ 1K potassium silicate 2.4g
(SiO ₂ / K ₂ O = 1.9)
・ The following compound 5.0 g
・ Ethylenediaminetetraacetic acid ・ 4Na salt 0.1g
・ Water 91.3g

  In Table 1, the structure of the sensitizing dye according to the present invention used in the photopolymerization initiation system is the same as that of the exemplified compound. The structures of the initiator compounds (A-1) to (A-7) and the co-sensitizers (C-1) to (C-3) are as shown below. The following sensitizing dyes (DR-1) to (DR-4) used in Comparative Examples are dye compounds outside the scope of the present invention.

As is apparent from Table 1, all the lithographic printing plate precursors using the photosensitive composition of the present invention for the photosensitive layer can form an image with high sensitivity, and this photoinitiating system shows sufficient sensitivity for practical use. all right. On the other hand, Comparative Examples 1 and 2 using only the sensitizing dye and only the initiator compound do not form an image, and the photoinitiating system is a combination of the initiator compound and a known sensitizing dye that is outside the scope of the present invention. It was clear that the lithographic printing plate precursors of Comparative Examples 3 and 4 using No. 1 could not obtain sufficient sensitivity for practical use. It can be seen from Examples 1 to 15 that the photosensitive composition of the present invention can be applied in a wide range regardless of the sensitization mechanism. Further, by comparing Example 3 with Comparative Examples 3 and 4, the structural characteristic that the sensitizing dye of the present invention exhibits high sensitivity is the specific structure represented by the general formula (1), for example, the iminooxazolidinone structure. It is suggested. Further, the comparison between Example 3 and Comparative Example 5 and Example 15 and Comparative Example 6 suggests that the structural feature showing the effect of improving storage stability is in the partial structure of the sensitizing dye of the present invention. This was an unexpected discovery.

<Examples 16 to 22, Comparative Example 7>
An intermediate layer, a photosensitive layer, and a protective layer were sequentially formed on the support used in Examples 1 to 15 in the following procedure to prepare a lithographic printing plate precursor.
(Coating intermediate layer)
On the surface of the support so that the coating amount of phenylphosphonic acid is 20 mg / m ² ,
A coating solution having the following composition (A) was prepared, applied at 180 rpm with a wheeler, and then dried at 80 ° C. for 30 seconds to form an intermediate layer.

(Intermediate layer coating solution A)
Phenylphosphonic acid 0.07g ~ 1.4g
Methanol 200g

(Coating of photosensitive layer)
On the support provided with the intermediate layer, a photosensitive composition having the following composition was prepared, applied with a wheeler so that the coating amount was 1.0 to 2.0 g / m ² , and at 100 ° C. for 1 minute. A photosensitive layer was formed by drying.

(Photosensitive composition)
Addition polymerizable compound (compound described in Table 2) 1.6 g
Binder polymer (compound described in Table 2) 2.0 g
Sensitizing dye (compound described in Table 2) 0.15 g
Initiator compound (compound described in Table 2) 0.2 g
Co-sensitizer (compound described in Table 2) 0.3 g
Color pigment dispersion 2.0g
(Composition of pigment dispersion)
Pigment Blue 15: 6 15 parts by mass Allyl methacrylate / methacrylic acid copolymer 10 parts by mass
(Copolymerization molar ratio 83/17)
-Cyclohexanone 15 parts by mass-Methoxypropyl acetate 20 parts by mass-Propylene glycol monomethyl ether 40 parts by mass Thermal polymerization inhibitor 0.01 g
(N-nitrosophenylhydroxylamine aluminum salt)
Fluorosurfactant 0.02g
(Dai Nippon Ink Chemical Co., Ltd., MegaFuck F-780F)
Methyl ethyl ketone 20.0g
Propylene glycol monomethyl ether 20.0g

(Formation of protective layer)
On this photosensitive layer, a 3% by weight aqueous solution of polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 550) was applied so that the dry coating weight was 2 g / m ^2, and dried at 100 ° C. for 2 minutes for protection. A layer was formed to obtain a lithographic printing plate precursor.

(Exposure of planographic printing plate precursor)
Using the lithographic printing plate precursor obtained as described above, 400 nm monochromatic light as a light source, adjusting the exposure power so that the plate surface exposure energy density is 100 μJ / cm ² , solid image exposure and 175 lines / inch, Halftone image exposure was performed from 1 to 99% in 1% increments.

(Development / plate making)
A predetermined developer (described in Table 2) and a finisher FP-2W manufactured by Fuji Photo Film Co., Ltd. were loaded into an automatic processor LP-850 manufactured by Fuji Photo Film Co., Ltd., respectively, and the developer temperature was 30 ° C. and the development time was 18 seconds. The exposed plate was developed / engraved under the following conditions to obtain a lithographic printing plate.

(Print durability test)
R201 manufactured by Roland was used as the printing machine, and GEOS-G (N) manufactured by Dainippon Ink was used as the ink. While the printing was continued, the printed matter in the solid image portion was observed, and the printing durability was examined based on the number of sheets on which the image began to fade. The larger the number, the better the printing durability.

(Forced dot printing test)
R201 manufactured by Roland was used as the printing machine, and GEOS-G (N) manufactured by Dainippon Ink was used as the ink. On the 5000th sheet from the start of printing, PS plate cleaner CL-2 manufactured by Fuji Photo Film Co., Ltd. was soaked in a printing sponge, the halftone dots were wiped, and the ink on the printing plate was washed. Thereafter, 10,000 sheets were printed, and the presence or absence of halftone dots in the printed matter was visually observed.

(Stain resistance test)
Printing is performed using R201 manufactured by Roland as a printing machine and GEOS-G (S) manufactured by Dainippon Ink Co., Ltd. as an ink, and the obtained printed matter is observed, and resistance to non-image areas (unexposed areas) is confirmed. The state of dirtiness was evaluated visually.

(Addition polymerizable compound in Table 2)
(M-1): The aforementioned urethane bond-containing addition polymerizable compound (M-1)
(M-2): Pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .; NK ester A-TMMT)
(M-3): Glycerin dimethacrylate hexamethylene diisocyanate urethane prepolymer (manufactured by Kyoeisha Chemical Co., Ltd .; UA101H)

(Binder polymer in Table 2)
(B-1): Allyl methacrylate / methacrylic acid / N-isopropylacrylamide (copolymerization molar ratio 68/12/20)
Measured acid value obtained by NaOH titration 1.12 meq / g
Mass average molecular weight 100,000 determined by GPC measurement (U-1): Polyurethane resin which is a polycondensation product of the following diisocyanate and diol. 4,4′-diphenylmethane diisoisocyanate (MDI)
・ Hexamethylene diisocyanate (HMDI)
-Polypropylene glycol, mass average molecular weight 1000 (PPG1000)
・ 2,2-bis (hydroxymethyl) propionic acid (DMPA)
・ Glycerin monomethacrylate (Blemmer GLM manufactured by NOF Corporation)
[Copolymerization molar ratio (MDI / HMDI / PPG1000 / DMPA / Blemmer GLM = 80/20/22/52/26)]
Measured acid value obtained by KOH titration 0.92 meq / g
Mass average molecular weight of 60,000 determined by GPC measurement

(Developer in Table 2)
(DV-1)
Aqueous solution of pH 10 having the following composition: 0.1 parts by mass of monoethanolamine 1.5 parts by mass of triethanolamine 4.0 parts by mass of the compound of the following formula 1 3 compounds 0.2 parts by mass Water 91.7 parts by mass

(DV-2)
Aqueous solution of pH 10 consisting of the following composition: Sodium hydrogen carbonate 1.2 parts by mass Sodium carbonate 0.8 parts by mass Compound of the following formula 1 3.0 parts by mass Compound of the following formula 2 2.0 parts by mass Compound of 0.2 parts by mass ・ Water 92.8 parts by mass

(DV-3)
PH 13 aqueous solution having the following composition: 1K potassium silicate 3.0 parts by mass Potassium hydroxide 1.5 parts by mass Compound of the following formula 3 0.2 parts by mass Water 95.3 parts by mass

(DV-4)
The developer of pH 12 used in Examples 1-16

(Where R is H or C ₄ H ₉ and n is about 4 (average value).)

  As is apparent from Table 2, all of the lithographic printing plate precursors of Examples 16 to 22 using the photosensitive composition of the present invention as the photosensitive layer were capable of making a plate with high productivity by scanning exposure, that is, It was also found that an excellent lithographic printing plate can be provided even under low energy exposure conditions. On the other hand, with the lithographic printing plate precursor of Comparative Example 7 that does not use the sensitizing dye according to the present invention, a practical lithographic printing plate could not be obtained.

Claims (3)

(A) a sensitizing dye represented by the following general formula (1),
A photosensitive composition containing (B) an initiator compound capable of generating a radical, an acid or a base, and (C) a polymerizable compound which reacts with at least one of a radical, an acid or a base.

(In the general formula (1), A represents an aromatic ring or a heterocyclic ring which may have a substituent. R3 represents a hydrogen atom or a monovalent nonmetallic atomic group, and R4 and R5 each independently represents Represents a monovalent nonmetallic atomic group, R6 represents a hydrogen atom or a monovalent nonmetallic atomic group, and A, R3, R4, R5, and R6 are bonded to each other to form an aliphatic group or an aromatic group. Z represents a 5-membered or 6-membered ring structure containing a hetero atom.) (A) a sensitizing dye represented by the following general formula (2),
A photosensitive composition containing (B) an initiator compound capable of generating a radical, an acid or a base, and (C) a polymerizable compound which reacts with at least one of a radical, an acid or a base.

(In the general formula (2), A represents an aromatic ring or a hetero ring which may have a substituent, X represents an oxygen atom, a sulfur atom, or -NR1-. R1, R2, R3, and R6 represent Each independently represents a hydrogen atom or a monovalent non-metallic atomic group, and R 4 and R 5 each independently represents a monovalent non-metallic atomic group A, R 3, R 4, R 5 and R 6 are bonded to each other; Aliphatic or aromatic rings can be formed.)   The photosensitive composition according to claim 1 or 2, wherein the initiator compound capable of generating (B) radical, acid or base is a hexaarylbiimidazole compound.