JP2005099257A - Photosensitive composition and image recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition which is excellent in high printing durability, handling property in a bright room, work efficiency, economic property and storage stability, and which is used as a planographic printing plate for scanning exposure suitable for a CTP system or as an image recording material having high sensitivity to the oscillation wavelength of an inexpensive semiconductor laser. <P>SOLUTION: The photosensitive composition contains: (i) a sensitizing dye having a specified structure; (ii) an acylphosphine compound; and (iii) a compound which reacts with at least either radical or acid and undergoes irreversible changes in its physical and chemical characteristics. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a photosensitive composition containing a novel photoinitiating system, particularly a photoinitiating system excellent in high sensitivity, high printing durability, and bright room handling. The present invention also particularly relates to a photosensitive composition that is excellent as a material for a lithographic printing plate precursor capable of making a plate by scanning exposure based on a digital signal. Furthermore, for example, it is used for image formation such as stereolithography, holography, and color hard copy, in the field of manufacturing electronic materials such as photoresists, and for photocurable resin materials such as inks, paints, and adhesives.

  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 is widely used. As a plate making method, mask exposure (surface exposure) is usually performed through a lithographic film. 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 technique have come into practical use. As a result, a computer-to-plate (CTP) technique for scanning a highly directional light such as a laser beam in accordance with digitized image information and directly manufacturing a printing plate without using a lith film is desired. Therefore, it is an important technical problem to obtain a printing plate precursor adapted to this.

  As one of the methods for obtaining such a lithographic printing plate capable of scanning exposure, an ink-receptive photosensitive resin layer (hereinafter referred to as a photosensitive layer) provided on a hydrophilic support has been excellent in photosensitive speed. A configuration using a photopolymerization composition has been proposed and is already on the market. The original plate having such a constitution has a desirable printing plate and printing performance such that it is easy to develop and further has excellent resolution, inking properties, printing durability and stain resistance.

  The above photopolymerizable composition basically comprises an ethylenically unsaturated compound, a photopolymerization initiation system, and a binder resin, and image formation is performed by the photoinitiation system absorbing light and generating active radicals. This causes addition polymerization of the compound and insolubilization of the photosensitive layer. Most of the conventional proposals relating to the photopolymerizable composition capable of scanning exposure disclose the use of a photoinitiating system excellent in photosensitivity, for example, many are described in Non-Patent Documents 1 and 2, etc. Yes.

  Regarding the photopolymerizable composition comprising these photoinitiating systems and 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 a light source, In order to increase the productivity, it is desired to write at a higher speed, but this is not reached because the output of the light source is not sufficiently high and the sensitivity of the photosensitive material is not sufficiently high.

  On the other hand, in recent years, for example, a semiconductor laser using an InGaN-based material and capable of continuous oscillation in a 350 nm to 450 nm region has become a practical stage. 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, a light-sensitive material having a short photosensitive area capable of working under a brighter safelight can be used as compared with a system using a conventional FD-YAG or Ar laser.

  Further, for example, as described in Non-Patent Documents 3 and 4, obtaining a highly sensitive photoinitiating system is a technique that is still widely desired in the imaging field.

  However, no photoinitiation system having a sufficient sensitivity for scanning exposure in a short wavelength region of 350 nm to 450 nm is known to date.

For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-351072) discloses a combination of a bisbenzothiazole type sensitizing dye and a titanocene compound, which is highly sensitive, but the titanocene compound itself has light absorption up to around 550 nm. However, the present situation is not preferable in terms of safety of the yellow light. Photopolymerizable compositions using acylphosphine compounds as photoinitiators are well known and are used in inks, coating materials, printing plates and the like. US Pat. No. 4,292,152 describes the use of an acyl phosphine oxide initiator to improve the photosensitivity of the polymerizable composition. The acylphosphine photoinitiator can be used alone, but it is also known that a sensitizing action can be obtained by adding an appropriate compound. JP-A-4-220404 discloses a combination with benzophenone, JP-A-8-305018 discloses a combination with coumarin and thiophene, and JP-A-9 / 31051. No. pamphlet) discloses a combination with fluoranthene. Patent Document 6 (Japanese Patent Laid-Open No. 3-296759) discloses a method using a benzdithiol type compound as a photopolymerization initiator. Although these are certainly high in sensitivity, they are not yet sufficient, and practically sufficient sensitivity cannot be obtained when a laser light source having a wavelength of 450 nm or less is used.
Bruce M. By Bruce M. Monroe et al., Chemical Review, Vol. 93, (1993), pp. 435-448. R. S. R. Davidson, Journal of Photochemistry and Biology A: Chemistry, Vol. 73, (1993), pp. 81-96 J. et al. P. By JF Faussier, Photoinitiated Polymerization-Theory and Applications (Rapra Review), Vol. 9, Report, Rapra Technology (1998) M.M. Tsunooka et al., Prog. Polym. Sci., 21, 1 (1996) Japanese Patent Laid-Open No. 2002-351072 U.S. Pat. No. 4,292,152 JP-A-4-220404 JP-A-8-305018 International Publication No. 97/31051 Pamphlet JP-A-3-296759

  The object of the present invention is to provide an oscillation wavelength of a lithographic printing plate for scanning exposure or an inexpensive semiconductor laser, which is excellent in high sensitivity, high printing durability, bright room handling, workability, economy, and storage stability, and is compatible with a CTP system. Is to provide a photosensitive composition used as a highly sensitive image recording material.

  Another object of the present invention is to provide an image recording material having a photosensitive layer formed from a photosensitive composition that uses a novel photopolymerization initiation system that is highly sensitive to wavelengths from 350 nm to 450 nm. .

  As a result of intensive studies to achieve the above object, the present inventors have obtained sufficient sensitivity to the oscillation wavelength of a short-wave semiconductor laser when the sensitizing dye has a structure represented by the following general formula (1). In addition, the inventors have found that a photosensitive composition having high printing durability, bright room handling, workability, economy, and storage stability can be obtained, and the present invention has been achieved.

That is, the present invention is as follows.
(1) (i) a sensitizing dye represented by the following general formula (1);
(Ii) an activator compound that undergoes a chemical change by interaction with light absorption of a sensitizing dye represented by the following general formula (1) to generate at least one of a radical and an acid;
(Iii) A photosensitive composition comprising a compound that reacts with at least one of a radical and an acid and whose physical or chemical properties change irreversibly.

(In the formula, X represents an oxygen atom or a sulfur atom, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ are each independently a hydrogen atom or a monovalent atom. Represents a nonmetallic atomic group.)
(2) The photosensitive composition as described in (1) above, wherein the activator compound of (ii) contains at least one acylphosphine compound.
(3) An image recording material in which the photosensitive composition according to (1) or (2) is provided on a support.

   Although the mechanism of action of the present invention is not clear, the sensitizing dye represented by the general formula (1) is highly sensitive to wavelengths from 350 nm to 450 nm, and is irradiated with an oscillation wavelength of an inexpensive short-wave semiconductor laser (exposure). ) In an electronically excited state with high sensitivity, and the electron transfer, energy transfer, heat generation, and the like related to the electronically excited state by light absorption cause a chemical change in the coexisting initiator compound to generate a radical or an acid. Furthermore, an irreversible change such as color development, decoloration, polymerization or the like is caused in a compound whose physical or chemical properties are irreversibly changed by at least one of the radicals and acids generated here. By using an addition polymerizable compound having an ethylenically unsaturated double bond, which is preferable among such 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, and has no maximum absorption in the ultraviolet region, so that it is stable under white light. It has the advantage that it can be handled even under bright fluorescent lamps. Therefore, in this photosensitive composition, a lithographic printing plate precursor using an addition polymerizable compound as a photosensitive layer can be recorded with high sensitivity, excellent safelight stability, and undesired non-image area. The occurrence of smudges is suppressed, and it is considered that excellent printing performance is exhibited.

  According to the present invention, it has high printing durability, light room handling, workability, economy, and storage stability, and is superior to the oscillation wavelength of a lithographic printing plate for scanning exposure suitable for a CTP system or an inexpensive semiconductor laser. There is provided a photosensitive composition used as a material for a sensitive lithographic printing plate precursor. According to the present invention, it is also possible to provide an image recording material having a photosensitive layer formed from a photosensitive composition using a novel photopolymerization initiation system that is highly sensitive to wavelengths from 350 nm to 450 nm.

  Embodiments of the present invention will be described in detail.

  The photosensitive composition of the present invention comprises (A) a photopolymerization initiation system, (B) a compound that reacts with at least one of a radical and an acid, and whose physical or chemical properties change irreversibly. Further, if necessary, it comprises (C) a binder polymer. Hereinafter, these components will be specifically described.

(A) Photopolymerization initiation system The photopolymerization initiation system, which is an essential component of the photosensitive composition of the present invention, produces (A1) a sensitizing dye having a specific structure, (A2) a radical, and an acid. And an activator compound. In this system, (A1) the activator compound undergoes a chemical change by the action of electron transfer, energy transfer, heat generation, etc. due to the electronically excited state generated by light absorption of the sensitizing dye represented by the general formula (1), and radicals And / or acid (this process is called dye sensitization). First, this photopolymerization initiation system will be described.

  One of the characteristics of the sensitizing dye (A1) of the present invention is that it has particularly excellent absorption characteristics in the region of 300 nm to 450 nm. Furthermore, (A1) efficiently causes degradation of various active agents and exhibits very high photosensitivity. In general, the sensitization mechanism of a photoinitiating system consisting of a sensitizing dye / active agent is 1) reductive decomposition of the active agent based on the electron transfer reaction from the electronically excited state of the sensitizing dye to the active agent, 2) from the active agent Oxidative decomposition of the active agent based on the electron transfer to the electronically excited state of the sensitizing dye, 3) decomposition of the active agent from the electronically excited state based on the energy transfer from the electronically excited state of the sensitizing dye to the active agent, The sensitizing dye of the present invention has been found to cause any of these types of sensitizing reactions with excellent efficiency.

The present inventors have found that it is very important that the sensitizing dye has a partial structure represented by the general formula (1) in order to obtain high sensitivity, but the mechanism of action is not clear. . The sensitizing dye of the present invention exhibits a high-intensity emission (fluorescence and / or phosphorescence) spectrum. From this, one possibility is that the sensitizing dye of the present invention having the above partial structure has a relatively long excitation life, and therefore, it is considered that it acts on the efficiency of the reaction with the activator compound. As another possibility, the partial structure represented by the general formula (1) contributes to the efficiency of the initial sensitization process (electron transfer, etc.) and the efficiency of the subsequent reaction leading to the decomposition of the activator compound. There is a possibility.
(A1) Sensitizing dye The sensitizing dye used in the present invention is represented by the following general formula (1).

In general formula (1), X represents an oxygen atom or a sulfur atom, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ are each independently a hydrogen atom or Represents a monovalent nonmetallic atomic group.

The general formula (1) will be described in detail below.
As the monovalent non-metallic atomic group represented by R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ (hereinafter sometimes abbreviated as R _{1 to} R ₆ ), , Halogen atoms, and substituted or unsubstituted alkyl groups having 20 or less carbon atoms, alkoxy groups, acyl groups, aryl groups, aralkyl groups, alkenyl groups, alkylthio groups, aryloxy groups, arylthio groups, heteroaryl groups, and alkyl sulfones Groups.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  Examples of the substituted or unsubstituted alkyl group include linear, branched or cyclic alkyl groups, alkoxyalkyl groups, alkoxyalkoxyalkyl groups, alkoxyalkoxyalkoxyalkyl groups, alkoxycarbonylalkyl groups, alkoxycarbonyloxyalkyl groups, alkoxyalkoxycarbonyloxy groups. Alkyl group, hydroxyalkyl group, hydroxyalkoxyalkyl group, hydroxyalkoxyalkoxyalkyl group, cyanoalkyl group, acyloxyalkyl group, acyloxyalkoxyalkyl group, acyloxyalkoxyalkoxyalkyl group, alkyl halide, sulfonealkyl group, alkylcarbonylaminoalkyl group , Alkylsulfonaminoalkyl group, sulfonamidoalkyl group, alkylaminoalkyl group Aminoalkyl groups, and they are selected from alkyl sulfonic alkyl group.

  As the linear, branched or cyclic alkyl group, in consideration of processability by application to a polycarbonate, acrylic, epoxy, polyolefin substrate or the like, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n- Butyl group, iso-butyl group, sec-butyl group, t-butyl group, n-pentyl group, iso-pentyl group, 2-methylbutyl group, 1-methylbutyl group, neo-pentyl group, 1,2-dimethylpropyl group 1,1-dimethylpropyl group, cyclo-pentyl group, n-hexyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group 2,3-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 1,2-dimethylbutyl group 1,1-dimethylbutyl group, 3-ethylbutyl group, 2-ethylbutyl group, 1-ethylbutyl group, 1,2,2-trimethylbutyl group, 1,1,2-trimethylbutyl group, 1-ethyl-2- Methylpropyl group, cyclo-hexyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2,4-dimethylpentyl group, n-octyl group 2-ethylhexyl group, 2,5-dimethylhexyl group, 2,5,5-trimethylpentyl group, 2,4-dimethylhexyl group, 2,2,4-trimethylpentyl group, 3,5,5-trimethylhexyl Group, n-nonyl group, n-decyl group, 4-ethyloctyl group, 4-ethyl-4,5-methylhexyl group, n-undecyl group, n-dodecyl group, 1, , 5,7-tetraethyloctyl group, 4-butyloctyl group, 6,6-diethyloctyl group, n-tridecyl group, 6-methyl-4-butyloctyl group, n-tetradecyl group, n-pentadecyl group, 3, 5-dimethylheptyl group, 2,6-dimethylheptyl group, 2,4-dimethylheptyl group, 2,2,5,5-tetramethylhexyl group, 1-cyclo-pentyl-2,2-dimethylpropyl group, 1 -Cyclo-hexyl-2,2-dimethylpropyl group and the like can be mentioned.

  Examples of alkoxyalkyl groups include methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl, methoxyethyl, ethoxyethyl, propoxyethyl, butoxyethyl, n-hexyloxyethyl, 4-methyl. Pentoxyethyl group, 1,3-dimethylbutoxyethyl group, 2-ethylhexyloxyethyl group, n-octyloxyethyl group, 3,5,5-trimethylhexyloxyethyl group, 2-methyl-1-iso-propylpropoxy Ethyl group, 3-methyl-1-iso-propylbutyloxyethyl group, 2-ethoxy-1-methylethyl group, 3-methoxybutyl group, 3,3,3-trifluoropropoxyethyl group, 3,3,3 -A trichloropropoxyethyl group etc. are mentioned.

  Examples of alkoxyalkoxyalkyl groups include methoxyethoxyethyl, ethoxyethoxyethyl, propoxyethoxyethyl, butoxyethoxyethyl, hexyloxyethoxyethyl, 1,2-dimethylpropoxyethoxyethyl, 3-methyl-1 -Iso-butylbutoxyethoxyethyl group, 2-methoxy-1-methylethoxyethyl group, 2-butoxy-1-methylethoxyethyl group, 2- (2'-ethoxy-1'-methylethoxy) -1-methylethyl Group, 3,3,3-trifluoropropoxyethoxyethyl group, 3,3,3-trichloropropoxyethoxyethyl group and the like.

  Examples of alkoxyalkoxyalkoxyalkyl groups include methoxyethoxyethoxyethyl group, ethoxyethoxyethoxyethyl group, butoxyethoxyethoxyethyl group, 2,2,2-trifluoroethoxyethoxyethoxyethyl group, 2,2,2-trichloroethoxy An ethoxyethoxyethyl group etc. are mentioned.

  Examples of alkoxycarbonylalkyl groups include methoxycarbonylmethyl, ethoxycarbonylmethyl, butoxycarbonylmethyl, methoxycarbonylethyl, ethoxycarbonylethyl, butoxycarbonylethyl, 2,2,3,3-tetrafluoropropoxy Examples thereof include a carbonylmethyl group and a 2,2,3,3-tetrachloropropoxycarbonylmethyl group.

  Examples of alkoxycarbonyloxyalkyl groups include methoxycarbonyloxyethyl, ethoxycarbonyloxyethyl, butoxycarbonyloxyethyl, 2,2,2-trifluoroethoxycarbonyloxyethyl, 2,2,2-trichloroethoxy Examples thereof include a carbonyloxyethyl group.

  Examples of the alkoxyalkoxycarbonyloxyalkyl group include methoxyethoxycarbonyloxyethyl group, ethoxyethoxycarbonyloxyethyl group, butoxyethoxycarbonyloxyethyl group, 2,2,2-trifluoroethoxyethoxycarbonyloxyethyl group, 2,2 , 2-trichloroethoxyethoxycarbonyloxyethyl group and the like.

  Examples of the hydroxyalkyl group include 2-hydroxyethyl group, 4-hydroxyethyl group, 2-hydroxy-3-methoxypropyl group, 2-hydroxy-3-chloropropyl group, 2-hydroxy-3-ethoxypropyl group, Examples include 3-butoxy-2-hydroxypropyl group, 2-hydroxy-3-phenoxypropyl group, 2-hydroxypropyl group, 2-hydroxybutyl group and the like.

  Examples of hydroxyalkoxyalkyl groups include hydroxyethoxyethyl, 2- (2′-hydroxy-1′-methylethoxy) -1-methylethyl, 2- (3′-fluoro-2′-hydroxypropoxy) ethyl Group, 2- (3′-chloro-2′-hydroxypropoxy) ethyl group and the like.

  Examples of hydroxyalkoxyalkoxyalkyl groups include hydroxyethoxyethoxyethyl group, [2 ′-(2′-hydroxy-1′-methylethoxy) -1′-methylethoxy] ethoxyethyl group, [2 ′-(2 ′). -Fluoro-1'-hydroxyethoxy) -1'-methylethoxy] ethoxyethyl group, [2 '-(2'-chloro-1'-hydroxyethoxy) -1'-methylethoxy] ethoxyethyl group, and the like. .

  Examples of the cyanoalkyl group include 2-cyanoethyl group, 4-cyanobutyl group, 2-cyano-3-methoxypropyl group, 2-cyano-3-chloropropyl group, 2-cyano-3-ethoxypropyl group, 3- Examples include butoxy-2-cyanopropyl group, 2-cyano-3-phenoxypropyl group, 2-cyanopropyl group, and 2-cyanobutyl group.

  Examples of the acyloxyalkyl group include an acetoxyethyl group, a propionyloxyethyl group, a butyryloxyethyl group, a valeryloxyethyl group, a 1-ethylpentylcarbonyloxyethyl group, and a 2,4,4-trimethylpentylcarbonyloxyethyl group. , 3-fluorobutyryloxyethyl group, 3-chlorobutyryloxyethyl group, and the like.

  Examples of acyloxyalkoxyalkyl groups include acetoxyethoxyethyl group, propionyloxyethoxyethyl group, valeryloxyethoxyethyl group, 1-ethylpentylcarbonyloxyethoxyethyl group, 2,4,4-trimethylpentylcarbonyloxyethoxyethyl group , 2-fluoropropionyloxyethoxyethyl group, 2-chloropropionyloxyethoxyethyl group, and the like.

  Examples of acyloxyalkoxyalkoxyalkyl groups include acetoxyethoxyethoxyethyl group, propionyloxyethoxyethoxyethyl group, valeryloxyethoxyethoxyethyl group, 1-ethylpentylcarbonyloxyethoxyethoxyethyl group, 2,4,4-trimethylpentyl. Examples include carbonyloxyethoxyethoxyethyl group, 2-fluoropropionyloxyethoxyethoxyethyl group, 2-chloropropionyloxyethoxyethoxyethyl group, and the like.

  Examples of the halogenated alkyl group include a chloromethyl group, a chloroethyl group, a 2,2,2-trifluoroethyl group, a trifluoromethyl group, a bromomethyl group, and a methyl iodide group.

  Examples of the sulfonealkyl group include a sulfonemethyl group, a sulfoneethyl group, and a sulfonepropyl group.

  Examples of the alkylcarbonylaminoalkyl group include a methylcarbonylaminoethyl group, an ethylcarbonylaminoethyl group, a propylcarbonylaminoethyl group, a cyclohexylcarbonylaminoethyl group, a succiniminoethyl group, and the like.

  Examples of the alkylsulfonaminoalkyl group include a methylsulfonaminoethyl group, an ethylsulfonaminoethyl group, a propylsulfonaminoethyl group, and the like.

  Examples of the sulfonamidoalkyl group include a sulfonamidomethyl group, a sulfonamidoethyl group, and a sulfonamidopropyl group.

  Examples of alkylaminoalkyl groups include N-methylaminomethyl, N, N-dimethylaminomethyl, N, N-diethylaminomethyl, N, N-dipropylaminomethyl, N, N-dibutylaminomethyl. Groups and the like.

  Examples of the aminoalkyl group include an aminomethyl group, an aminoethyl group, and an aminopropyl group.

  Examples of alkyl sulfone alkyl groups include methyl sulfone methyl group, ethyl sulfone methyl group, butyl sulfone methyl group, methyl sulfone ethyl group, ethyl sulfone ethyl group, butyl sulfone ethyl group, 2,2,3,3-tetrafluoropropyl Examples thereof include a sulfonemethyl group and a 2,2,3,3-tetrachloropropylsulfonemethyl group.

  Examples of the substituted or unsubstituted alkoxy group include an alkoxy group having the same substituent as the alkyl group listed above, and preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, n Examples include lower butoxy groups such as -butoxy group, iso-butoxy group, sec-butoxy group, t-butoxy group, n-pentoxy group, iso-pentoxy group, neo-pentoxy group, and 2-methylbutoxy group.

  Examples of the substituted or unsubstituted acyl group are acyl groups having the same substituents as the alkyl groups listed above, preferably a formyl group, a methylcarbonyl group, an ethylcarbonyl group, an n-propylcarbonyl group, iso-propylcarbonyl group, n-butylcarbonyl group, iso-butylcarbonyl group, sec-butylcarbonyl group, t-butylcarbonyl group, n-pentylcarbonyl group, iso-pentylcarbonyl group, neo-pentylcarbonyl group, 2- Examples thereof include a methylbutylcarbonyl group and a nitrobenzylcarbonyl group.

  Examples of the substituted or unsubstituted aryl group are aryl groups having the same substituents as the alkyl groups listed above, and preferably a phenyl group, a nitrophenyl group, a cyanophenyl group, a hydroxyphenyl group, a methylphenyl group. Group, trifluoromethylphenyl group, naphthyl group, nitronaphthyl group, cyanonaphthyl group, hydroxynaphthyl group, methylnaphthyl group, trifluoromethylnaphthyl group and the like.

  Examples of the substituted or unsubstituted aralkyl group are aralkyl groups having the same substituents as the alkyl groups listed above, preferably benzyl group, nitrobenzyl group, cyanobenzyl group, hydroxybenzyl group, methylbenzyl Group, trifluoromethylbenzyl group, naphthylmethyl group, nitronaphthylmethyl group, cyanonaphthylmethyl group, hydroxynaphthylmethyl group, methylnaphthylmethyl group, trifluoromethylnaphthylmethyl group and the like.

  Examples of the substituted or unsubstituted alkenyl group are alkenyl groups having the same substituents as the alkyl groups listed above, and are preferably a propenyl group, a 1-butenyl group, an iso-butenyl group, and a 1-pentenyl group. 2-pentenyl group, 2-methyl-1-butenyl group, 3-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2,2-dicyanovinyl group, 2-cyano-2-methylcarboxyl vinyl And lower alkenyl groups such as 2-cyano-2-methylsulfonvinyl group.

  Examples of the substituted or unsubstituted alkylthio group are alkylthio groups having the same substituents as the alkyl groups listed above, and preferably a methylthio group, an ethylthio group, an n-propylthio group, an iso-propylthio group, n Lower alkylthio such as -butylthio group, iso-butylthio group, sec-butylthio group, t-butylthio group, n-pentylthio group, iso-pentylthio group, neo-pentylthio group, 2-methylbutylthio group, methylcarboxylethylthio group Groups.

  Examples of the substituted or unsubstituted aryloxy group are aryloxy groups having the same substituents as the aryl groups listed above, preferably a phenoxy group, a 2-methylphenoxy group, a 4-methylphenoxy group, Examples include 4-t-butylphenoxy group, 2-methoxyphenoxy group, 4-iso-propylphenoxy group.

  Examples of the substituted or unsubstituted arylthio group are arylthio groups having the same substituents as the above-mentioned aryl groups, preferably a phenylthio group, a 4-methylphenylthio group, a 2-methoxyphenylthio group, 4-t-butylphenylthio group etc. are mentioned.

  Examples of substituted or unsubstituted heteroaryl groups include pyrrolyl, thienyl, furanyl, oxazoyl, isoxazoyl, oxadiazoyl, imidazolyl, benzoxazoyl, benzothiazoyl, benzoimidazolyl, benzofuranyl Group, indoyl group and the like.

  Examples of the substituted or unsubstituted alkylsulfone group are alkylsulfone groups having the same substituents as the above-mentioned alkyl groups, and preferably methylsulfone group, ethylsulfone group, n-propylsulfone group, iso -Propylsulfone group, n-butylsulfone group, iso-butylsulfone group, sec-butylsulfone group, t-butylsulfone group, n-pentylsulfone group, iso-butylsulfone group, neo-pentylsulfone group, 2-methyl A butyl sulfone group, 2-hydroxyethyl sulfone group, 2-cyanoethyl sulfone group, etc. are mentioned.

More preferable examples of R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ are substituted or unsubstituted from the viewpoint of enhancing compatibility with other photosensitive compositions. Of the alkyl group. Further, when an acylphosphine compound is used as an activator compound described later, X is preferably a sulfur atom in terms of sensitivity.

  The compound represented by the general formula (1) of the present invention can be prepared by a known method such as J. Org. Am. Chem. Soc. 63, 3203 (1941) and the like. That is, it can be produced by reacting the compound represented by the general formula (2) with the compound represented by the general formula (3) using hydrochloric acid or the like as a catalyst.

(In formulas (2) and (3), R _{1 to} R ₈ , X ₁ and X ₂ have the same meaning as described above.)
Preferred specific examples (D1) to (D19) of the compound represented by the general formula (1) are shown below, but the present invention is not limited thereto. In the following formula, Hex means an n-hexyl group.

  The sensitizing dye of the present invention can be subjected to various chemical modifications for improving the characteristics of the photosensitive layer when it is used as a lithographic printing plate precursor. 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, sensitizing dyes and radical generating parts (for example, reductive decomposable sites such as alkyl halides, oniums, peroxides, biimidazoles, oniums, biimidazoles, borate, amine, trimethylsilylmethyl, carboxymethyl, carbonyl, imine) And the like, particularly in a state where the concentration of the starting system is low, can be remarkably enhanced.

  Further, when the photosensitive composition of the present invention is used as a lithographic printing plate precursor, it is a preferred use mode of the photosensitive layer, which is hydrophilic for the purpose of improving the processability to an (alkali) aqueous developer. It is effective to introduce a functional moiety (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 to increase hydrophilicity. Have In addition, for example, a substituent can be appropriately introduced in order to improve the 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.

  Details of the usage such as which structure of these sensitizing dyes are used, whether they are used alone or in combination of two or more, and how much is added, can be appropriately set according to the performance design of the final photosensitive material. . For example, the compatibility with the photosensitive composition layer can be enhanced 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 physical properties of the photosensitive layer when used for a lithographic printing plate precursor. It is. The photosensitivity of the photosensitive layer, the resolution, and the physical properties of the exposed film are greatly affected by the absorbance at the light source wavelength. Therefore, 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 are cases 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, the substrate adhesion Will be insufficient. When used as a lithographic printing plate used in a relatively thin film thickness, the amount of sensitizing dye added is such that the absorbance of the photosensitive layer is in the range of 0.1 to 1.5, preferably in the range of 0.25 to 1. It is preferable to set so that When used as a lithographic printing plate, this is generally 0.05 to 30 parts by weight, preferably 0.1 to 20 parts by weight, more preferably 0.2 to 10 parts by weight with respect to 100 parts by weight of the photosensitive layer component. It is the range of mass parts.

(A2) Activator Compound The activator compound (hereinafter sometimes simply referred to as the activator), which is the second essential component of the photoinitiating system in the present invention, will be described.
The activator in the present invention is a compound that undergoes a chemical change through interaction with the electronically excited state of the sensitizing dye to generate at least one of a radical and an acid. Hereinafter, the radicals and acids generated in this way are simply called active species. When these compounds are not present, or when only the activator is used alone, practically sufficient sensitivity cannot be obtained, but as one aspect of using the sensitizing dye and the activator 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 activator compound by 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 the activator based on the electron transfer reaction from the electron excited state of the sensitizing dye to the activator, 2) the activator based on the electron transfer from the activator to the electron excited state of the sensitizing dye 3) Decomposition of the active agent from the electronically excited state based on energy transfer from the electronically excited state of the sensitizing dye to the active agent. Although it is often ambiguous as to which type of individual activator compounds 1) to 3), the major characteristic of the sensitizing dye in the present invention is a combination with any type of these activators. However, it has a very high sensitizing effect.

  Specific activator compounds known to those skilled in the art can be used without limitation, for example, Bruce M. Monroe et al., Chemical Revue, 93, 435 (1993), RSD Davidson, Journal of Photochemistry. and biology A: Chemistry, 73. 81 (1993), JP Faussier "Photoinitiated Polymerization-Theory and Applications": Rapra Review vol. 9, Report, Rapra Technology (1998), M. Tsunooka et al., Prog. Polym. Sci., 21 and 1 (1996). Further, as other compounds having the functions 1) and 2), FDSaeva, Topics in Current Chemistry, 156, 59 (1990), GG Maslak, Topics in Current Chemistry, 168, 1 (1993) HBShuster et al, JACS, 112, 6329 (1990), IDFEaton et al, JACS, 102, 3298 (1980), etc. Also known.

  Hereinafter, with respect to specific examples of preferred active agents, (a) those that are reduced to cause bond cleavage to generate active species, (b) those that can be oxidized to cause bond cleavage to generate active species, (c) Although it will be described as being classified into the others, there are many cases where there is no general explanation as to which of the individual compounds belongs, and the present invention is not limited to the description of these reaction mechanisms.

  (A) Those that are reduced to cause bond cleavage and generate active species.

  Compounds having a carbon-halogen bond: It is considered that a carbon-halogen bond is reductively cleaved to generate an active species (for example, described in Polymer Preprints, Jpn., 41 (3) 542 (1992)). . As the active species, radicals and acids can be generated. Specifically, for example, those skilled in the art can easily synthesize by the synthesis method described in Journal of Heterocyclic chemistry, 7, 511 (1970) by MP Hutt, EFElslager and LM Merbel in addition to halomethyl-s-triazines. The halomethyl oxadiazoles which can be used, and the compounds described in German Patent Nos. 2641100, 3333450, 3021590, and 3021599 are preferably used.

  Compounds having a nitrogen-nitrogen bond or a 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, and in combination with hydrogen donors as necessary, radical chain reactions are initiated, and image formation using oxidation reactions with lophine radicals is also known (J. Imaging Sci., 30 , 215 (1986)).

  Compound having 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 compound: It is considered that a carbon-hetero bond or oxygen-nitrogen bond is reductively cleaved to generate an 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. , 294443, 297442, 279210, 422570, U.S. Pat. Nos. 3,902,144, 4,933,377, 4760013, 4,734,444 and 2,833,827, sulfonium salts and diazonium salts ( Benzenediazonium which may have a substituent, etc.), diazonium salt resins (formaldehyde resin of diazodiphenylamine, etc.), N-alkoxypyridinium salts, etc. (eg, US Pat. No. 4,743,528, JP-A-63-138345). No. 6 -142345, JP-A-63-142346, JP-B-46-42363, etc., specifically 1-methoxy-4-phenylpyridinium tetrafluoroborate, etc.), and The compounds described in JP-A 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 or carboxylic acid, esters of sulfonic acid or carboxylic acid with 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, JP-A-60. No. 198538, Japanese Patent Laid-Open No. 53-133022, nitrobenzester compounds, European Patents 0996672, 84515, 199672, 0441115, 0101122, US Pat. Nos. 4,618,564, 4371605, No. 4431774, JP-A-64-18143, JP-A-2-245756, JP-A-4-365048, JP-B-62-6223, JP-B-63-14340, In JP-A-59-174831 It includes placing the compound and the like, further, include, 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) Those that are oxidized to cause bond cleavage and generate active species.
Alkylate complex: It is considered that a carbon-hetero bond is oxidatively cleaved to generate an active radical (for example, as described in 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 (see, 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 can function as an activator. Specific examples include organometallic compounds such as titanocene, aromatic ketones, acylphosphines, bisacylphosphines, and the like, and active species can generate radicals and acids.

Hereinafter, among the activator compounds used in the present invention, preferred compounds particularly excellent in sensitivity and stability are specifically exemplified.
(1) Halomethyltriazines The compounds represented by the following general formula [I] are exemplified. In particular, it excels in radical generation and acid generation ability.

In the formula [I], X represents a halogen atom. Y ¹ represents ^{_{-CX 3, -NH 2, -NHR 1}} ', -N (R 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-trichlorome Ru-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) Borate salt compounds Borate salts represented by the following general formula [II] are excellent in radical generating ability.

In the general formula [II], R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may be the same or different from each other, and each is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted group. An alkenyl 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 combined to form a cyclic structure. May be. 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 and R ⁵⁹ represent an alkyl group having 1 to 14 carbon atoms or an aryl group) as a substituent. included.

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 general formula [II] include compounds described in the specifications of US Pat. Nos. 3,567,453 and 4,434,891, European Patent Nos. 109772 and 109773, and those shown below. Is mentioned.

(3) Hexaarylbiimidazoles Hexaarylbiimidazoles are excellent in stability and can generate 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-trifluoromethyl Eniru) -4,4 ', 5,5'-tetraphenyl biimidazole.
(4) Onium salt compounds Group 15 (5B), 16 (6B), 17 (7B) elements of the periodic table, specifically N, P, As, Sb, Bi, O, S, Se, Te, I These onium compounds are activators with excellent sensitivity. In particular, 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.

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

  “Organic peroxide” 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-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, parameterone hydroperoxide, 2,5-dimethylhexane-2,5-diha Dropper oxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, bis (t-butylperoxyisopropyl) 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 Oxide, diisopropyl peroxydicarbo , Di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, t-butyl percarbonate Oxyacetate, t-butylperoxypivalate, t-butylperoxyneodecanoate, t-butylperoxyoctanoate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butyl Peroxylaurate, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylmaleic acid, 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-hexylper) Oxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-octylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (cumylperoxycarbonyl) benzophenone, 3,3 ′, There are 4,4′-tetra (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogendiphthalate), carbonyldi (t-hexylperoxydihydrogendiphthalate), and the like.

  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 ′ Peroxide esters such as tetra (cumylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (p-isopropylcumylperoxycarbonyl) benzophenone, and di-t-butyldiperoxyisophthalate are preferred. .

(6) Acylphosphine compound Any acylphosphine compound may be used as long as it can generate an active radical when irradiated with light in the presence of the above-described sensitizing dye. Nos. 345790, 9-2604172, 7-278215, 10-29997, 10-505352, 10-95788, U.S. Pat.No. 5,407,969 The known compounds described can be appropriately selected and used.

More specifically, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name Lucillin from BASF) TPO), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide (trade name CGI available from Ciba) 403), bis (2,4,6-trimethylbenzoyl) isobutylphosphine oxide, 2,6-dimethyloxybenzoyl-2,4,6-trimethylbenzoyl-n-butylphosphine oxide, bis (2,4,6-trimethyl) Benzoyl) phenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-dibutoxyphenylphosphine oxide, 1,10-bis [bis (2,4,6-trimethylbenzoyl) phosphine oxide] decane, And tris (2-methylbenzoyl) phosphine oxide.

  Of the activator compounds specifically mentioned above, halomethyltriazine compounds and acylphosphine compounds are more preferred, and acylphosphine compounds are particularly preferred.

(B) A compound that reacts with at least one of a radical and an acid, and its physical or chemical properties change irreversibly. The third essential component (iii) in the present invention is the photoreaction of the above-mentioned photoinitiating system. Is a compound whose physical or chemical properties are changed and retained by the action of active species, and component (iii) is not particularly limited as long as it has such properties In many cases, for example, the compounds listed in the above-mentioned starting system themselves have such properties. The characteristics of the component (iii) that changes due to radicals and / or acids generated from the photoinitiating system include, for example, molecular properties such as absorption spectrum (color), chemical structure, polarizability, solubility, strength, This includes changes in material properties such as refractive index, fluidity, and adhesiveness.

  For example, as a component (iii), if a compound whose absorption spectrum changes with pH, such as a pH indicator, is used and an acid or base is generated from the initiation system, the color of only the exposed area can be changed. 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 (iii), it is possible to form an image by causing oxidation or reduction by radicals generated from the initiation system. Examples of such are, for example, J. Am. Chem. Soc., 108, 128 (1986), J. Imaging. Sci., 30, 215 (1986), Israel. J. Chem., 25, 264 (1986). Is disclosed.

  Moreover, a photocurable resin or a negative photopolymer can be formed by using a compound capable of addition polymerization or polycondensation as (iii) and combining with a starting system. As (iii), a radical polymerizable compound (such as a compound having an ethylenically unsaturated bond), a cationic polymerizable compound (such as an epoxy compound, a vinyl ether compound, or a methylol compound) or an anion polymerizable compound (such as an epoxy compound) is used. Such examples are described in, for example, Photopolymer Social Network, Photopolymer Handbook, Industrial Research Committee (1989), Polymers, 45, 786 (1996) and the like. Further, a composition using a thiol compound as (iii) and combined with a photo radical generating system is also well known.

  It is also useful to use an acid-decomposable compound as (iii) 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 include, for example, ACS. Symp. Ser. 242, 11 (1984), JP-A-60-3625, U.S. Pat. Nos. 5102771, 5,206,317, and 5212047. JP-A-4-26850, JP-A-3-1921731, JP-A-60-10247, JP-A-62-245050 and the like.

In the following, an addition-polymerizable compound having an ethylenically unsaturated double bond, which is one of the objects of the present invention, which is a particularly excellent component (iii) for the purpose of obtaining a highly sensitive lithographic printing plate precursor Will be described in more detail.
(B-1) Addition polymerizable compound The addition polymerizable compound having at least one ethylenically unsaturated double bond, which is a preferred component (iii) used in the present invention, has at least one terminal ethylenically unsaturated bond. It is selected from compounds having, preferably two 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.), 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.

  Furthermore, the ester monomers described above 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 (6) to a polyisocyanate compound having two or more isocyanate groups. Compounds and the like.

In general formula (6), 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.

  Furthermore, 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 and JP-B-1-40336, vinylphosphonic acid compounds described in JP-A-2-25493, and the like are listed. be able to. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, those introduced as photocurable monomers and oligomers in Journal of Japan Adhesion Association vol. 20, No. 7, pages 300 to 308 (1984) can also be used.

  For these addition-polymerizable compounds, details on how to use them, such as what type of structure is used, whether they are used alone or in combination, and how much is added, according to the performance design of the final photosensitive material, Can be set arbitrarily. 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, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image area, that is, the cured film, those having three or more functionalities are preferable, and furthermore, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrenic compound, vinyl ether type). A method of adjusting both photosensitivity and strength by using the compound) together is also effective. A compound having a large molecular weight or a compound having a high hydrophobicity is not preferable in terms of development speed and precipitation in a developing solution, although it is excellent in photosensitive speed and film strength.

  In addition, the selection and use method of the addition polymerization compound is an important factor for the compatibility and dispersibility with other components (for example, binder polymer, initiator, colorant, etc.) in the photosensitive composition. For example, the compatibility may be improved by using a low-purity compound or using two or more kinds in combination. In the case of using an original plate for a lithographic printing plate, a specific structure may be selected for the purpose of improving the adhesion of a support, an overcoat layer and the like described later. The preferable compounding ratio of the addition polymerizable compound in the photosensitive composition is 5 to 80% by mass, preferably 25 to 75% by mass with respect to all the components of the composition. 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, 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) Binder polymer In application to the lithographic printing plate precursor, which is a preferred embodiment of the present invention, it is preferable to further use a binder polymer in the photosensitive layer. The binder preferably contains a linear organic high molecular polymer. Any such “linear organic polymer” may be used. Preferably, a linear organic high molecular weight polymer that is soluble in water or weakly alkaline water or swellable that enables water development or weak alkaline water development 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. 7-2004, Japanese Patent Publication No. 7-120041, Japanese Patent Publication No. 7-120042, Japanese Patent Publication No. 8-12424, Japanese Patent Laid-Open No. 63-287944, Japanese Patent Laid-Open No. 63-287947, Japanese Patent Laid-Open No. The urethane-based binder polymer containing an acid group described in each of Japanese Patent Nos. 271741 and the like is very excellent in strength, and 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. Preferably it is 30-85 mass%. The photopolymerizable compound having an ethylenically unsaturated double bond and the linear organic 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 the 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, more preferably the acid value is 0.6 to 2.0 and the molecular weight is 10,000 to 300,000. It is a range.

(D) 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.
(D1) 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 photoreaction initiated by the light absorption of the initiation system described above, and various intermediate active species (radicals, peroxides, oxidizing agents, reducing agents, etc.) generated during the subsequent addition polymerization reaction, It is presumed that the sensitizer reacts to generate new active radicals. 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 an active radical is generated by reductive cleavage of the carbon-halogen bond. 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 the 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. Examples include oxime ethers.

Sulfinic acid salts: An active radical can be reductively generated. Specific examples include sodium arylsulfinate and the like.
(C) Compounds that react with radicals to convert into highly active radicals or act as chain transfer agents: For example, a group of compounds having SH, PH, SiH, GeH in the molecule is used. These can donate hydrogen to low-activity radical species to generate radicals, or can be oxidized and then deprotonated to generate radicals. Specific examples include 2-mercaptobenzimidazoles.

  More specific examples of these co-sensitizers are described, for example, in JP-A-9-236913 as additives for the purpose of improving sensitivity. Some examples are shown below, but the present invention is not limited thereto. In addition, -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, bonding with sensitizing dyes and activators, addition polymerizable unsaturated compounds and other parts, introduction of hydrophilic sites, compatibility improvement, introduction of substituents to suppress crystal precipitation, introduction of substituents to improve adhesion A method such as polymerization can be used.

  These co-sensitizers can be used alone or in combination of two or more. 0.05-100 mass parts is preferable with respect to 100 mass parts of compounds which have an ethylenically unsaturated double bond, More preferably, it is 1-80 mass parts, More preferably, it is the range of 3-50 mass parts.

(D2) 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 the production or storage of the photosensitive composition is prevented. Therefore, 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. In addition, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition due to oxygen, and a lithographic printing plate precursor is used. It may be unevenly distributed on the surface of the photosensitive layer in the course of drying. 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.

(D3) 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 the colorant, many dyes cause a decrease in the sensitivity of the photopolymerization type 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.

(D4) Other Additives Further, when the photosensitive composition of the present invention is used for a lithographic printing plate precursor, an inorganic filler, other plasticizer, or ink adhesion on the surface of the photosensitive layer is 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 meat | flesh 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), which will be described later, a UV initiator, a thermal crosslinking agent, or the like can be added to enhance the effect of heating and exposure after development.

  In addition, it is possible to provide an additive and an intermediate layer for improving the adhesion between the photosensitive layer and the support, and improving the development removability 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 increased. 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 provide a lithographic printing plate, when the photosensitive composition of the present invention is applied on a support, 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. And as for the density | concentration of solid content in a coating solution, 2-50 mass% is preferable.

The support coating amount of the photosensitive layer mainly affects the sensitivity of the photosensitive layer, the developability, the strength and printing durability of the exposed film, and is preferably selected as appropriate according to the application. For the lithographic printing plate for scanning exposure which is the main object of the present invention, the coating amount is preferably in the range of about 0.1 g / m ² to about 10 g / m ² in terms of the mass after drying. More preferably from 0.5 to 5 g / m ^2.

(E) Support In order to obtain a lithographic printing plate which is one of the main objects 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 (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), Paper or plastic film, etc., laminated or vapor-deposited with such metals is included, and these surfaces are appropriately known with known physical and chemical treatments for the purpose of imparting hydrophilicity and improving the strength as necessary. May be applied.

  In particular, preferred supports include paper, polyester film or aluminum plate, among which dimensional stability is good, relatively inexpensive, and a surface with excellent hydrophilicity and strength is provided by surface treatment as required. An aluminum plate which can be used 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 further aluminum is laminated or deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is at most 10% by mass. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and particularly preferably 0.2 mm to 0.3 mm.

  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.

  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, known methods such as a ball polishing method, a brush polishing method, a blast polishing method, a buffing method, and a polishing method can be used. In addition, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in an electrolytic solution such as hydrochloric acid or nitric acid. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used. Further, prior to roughening the aluminum plate, for example, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution, or the like is performed in order to remove the rolling oil on the surface, if desired.

  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.

  Furthermore, 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-described anodizing treatment and sodium silicate treatment A surface treatment combining these 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.

  Other preferred examples include those in which a water-resistant hydrophilic layer is provided as a surface layer on an arbitrary support. 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. A layer, a sol-gel film made of titanium oxide, polyvinyl alcohol, silicic acid or the like described in JP-A-8-507727 can be raised.

  These hydrophilic treatments are performed to make the surface of the support hydrophilic, in order to prevent harmful reaction of the photopolymerizable composition provided thereon, and to improve the adhesion of the photosensitive layer. It is given for the purpose.

(F) Protective layer In the lithographic printing plate for scanning exposure, which is a desirable mode of the present invention, a protective layer is further provided on the layer of the photopolymerizable composition in order to perform exposure in the air. Is preferred. The protective layer prevents exposure of oxygen and basic compounds such as low molecular weight compounds in the atmosphere that interfere with the image formation reaction caused by exposure in the photosensitive layer to allow exposure in the atmosphere. And Therefore, the properties desired for such a protective layer are low permeability of low-molecular compounds such as oxygen, and further, transmission of light used for exposure is not substantially inhibited, and adhesion to the photosensitive layer is excellent. And it is desirable that it can be easily removed in the development process after exposure.

  Such a device relating to 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 that is relatively excellent in 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, the use of polyvinyl alcohol as the main component gives the best results in terms of basic characteristics 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.

  Specific examples of polyvinyl alcohol include those hydrolyzed from 71 to 100% and having a molecular weight in the range of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, 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. In addition, adhesion to the image area and scratch resistance are extremely important in handling the plate.

  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 light transmission from 350 nm to 450 nm and that can absorb light of 500 nm or more, which is used for exposure, it is safe light without causing a decrease in sensitivity. Suitability can be further enhanced.

(G) Image forming method and plate making process When a photosensitive material using the photosensitive composition of the present invention is used as an image forming material, the exposed layer of the photosensitive layer is usually removed with a developer after image exposure. And get an image. Preferred developers when using these photopolymerizable compositions in the preparation of lithographic printing plates include those described in JP-B-57-7427, such as sodium silicate and potassium silicate. , 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 preferable to add so that the concentration of such an alkali 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, a nonionic compound represented by the following formula (IV) described in JP-A No. 2002-202616 is contained, the pH is 11.5 to 12.8, and 3 to 3 Examples thereof include a developer having a conductivity of 30 mS / cm.

A-W (IV)
In the formula, A represents a hydrophobic organic group having a log P of AH of 1.5 or more, and W represents a nonionic hydrophilic organic group having a log P of W-H of less than 1.0.

  This developer component is described in detail in paragraphs (0024) to (0067) of JP-A No. 2002-202616.

  In the present invention, it is effective to add the nonionic compound represented by the general formula (IV) in the developer in an amount of 0.1 to 15% by mass, preferably 1.0 to 8.0% by mass.

  In addition, as the plate making process of the lithographic printing plate precursor using the photosensitive composition of 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. Very strong conditions are used for heating after development. Usually, it is the range of 200-500 degreeC.

  As a method for exposing a scanning exposure lithographic printing plate using the photosensitive composition of 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. Further, the photosensitive composition of the present invention can be made soluble in neutral water or weak alkaline water by using a highly water-soluble one, but the lithographic printing plate precursor having such a configuration is used. After loading on the printing press, a system such as exposure-development can be performed on the press.

  As available laser light sources of 350 nm to 450 nm, the following can be used.

As a gas laser, Ar ion laser (364 nm, 351 nm, 10 mW to W), Kr ion laser (356 nm, 351 nm, 10 mW to 1 W), He—Cd laser (441 nm, 325 nm, 1 mW to 100 mW),
As a solid-state laser, Nd: YAG (YVO ₄ ) and SHG crystal × 2 combinations (355 nm, 5 mW to 1 W), Cr: LiSAF and SHG crystal combination (430 nm, 10 mW),
As a semiconductor laser system, a KNbO ₃ ring resonator (430 nm, 30 mW), a combination of a waveguide wavelength conversion element and AlGaAs, InGaAs semiconductor (380 nm to 450 nm, 5 mW to 100 mW), a waveguide wavelength conversion element and AlGaInP, an 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) and XeF (351 nm, pulse 10 to 250 mJ) are used as pulse lasers.

  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 the lithographic printing plate exposure apparatus of the scanning exposure method, there are an inner drum method, an outer drum method, and a flat bed method as an exposure mechanism, and a light source that can continuously oscillate among the light sources can be preferably used. . 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 to triple-beam exposure equipment that uses one or more gas lasers or solid-state laser light sources so that it becomes a semiconductor laser with a total output of 20 mW or more with an internal drum system. ・ A total output of 20 mW or more with a flatbed system. Multi-beam (1 to 10) exposure equipment that uses one or more semiconductor lasers, gas lasers, or solid-state lasers ・ Use one or more semiconductor lasers, gas lasers, or solid-state lasers to achieve a total output of 20 mW or more with the external drum system Multi-beam (1 to 9) exposure apparatus ・ Multi-beam (10 or more) exposure apparatus using one or more semiconductor lasers or solid-state lasers so that the total output is 20 mW or more in the external drum system. In general laser direct drawing type lithographic printing plates, photosensitive material sensitivity X (J / cm ² ), photosensitive material exposure Equation (eq 1) is established among the area S (cm ² ), the power q (W) of one laser light source, the number n of lasers, and the total exposure time t (s).

X · S = n · q · t (eq 1)
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 (eq 2) holds.

f · Z · t = Lx (eq 2)
ii) External drum (multi-beam) system Drum rotation speed F (radians / s), photosensitive material sub-scanning length Lx (cm), resolution Z (dots / cm), total exposure time t (s), number of beams In general, the equation (eq 3) is established during (n).

F.Z.n.t = Lx (eq 3)
iii) In the case of the flat head (multi-beam) system, 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 (eq 4)
Resolution (2560 dpi) required for an actual printing plate, plate size (A1 / B1, sub-scanning length 42 inch), exposure conditions of about 20 sheets / hour and photosensitive characteristics of the photosensitive composition of the present invention (photosensitive wavelength, By substituting (sensitivity: about 0.1 mJ / cm ² ) into the above formula, the photosensitive material using the photosensitive composition of the present invention can be combined with a multi-beam exposure method using a laser having a total output of 20 mW or more. It can be seen that it is particularly preferable. Further, by combining operability, cost, etc., a combination with an external drum type semiconductor laser multi-beam (10 or more) exposure apparatus is most preferable.

  Further, as other exposure light for the photosensitive composition of the present invention, ultrahigh pressure, high pressure, medium pressure, 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. Moreover, as a use of the photosensitive composition of this invention, it can apply without a restriction | limiting to what is widely known as a use of photocurable resin other than the lithographic printing plate for scanning exposure. 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 adhesiveness accompanying 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.
[Examples 1-14, Comparative Examples 1-6]
(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 display according to JIS B0601).

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 Tetraethyl silicate 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 mass Dimethyl phthalate 5 parts by mass Fluorosurfactant (N-butylperfluorooctane 0.7 parts by mass Sulfonamidoethyl acrylate / polyoxyethylene acrylate copolymer: molecular weight 20,000)
Methanol silica sol (manufactured by Nissan Chemical Industries, Ltd., methanol 30% by mass)
50 parts by mass Methanol 800 parts by mass

(Preparation of photosensitive layer)
On the aluminum plate thus treated, a photopolymerizable composition having the following composition was applied so that the dry coating amount was 1.0 g / m ² and dried at 80 ° C. for 2 minutes to form a photosensitive layer. .
・ Pentaerythritol tetraacrylate 1.6g
Allyl methacrylate / methacrylic acid / N-isopropyl acrylamide copolymer (copolymerization molar ratio 66/13/21) 2.0 g
-Photopolymerization initiation system (described in Table 2)
Sensitizing dye Xg
Activator Yg
Co-sensitizer Zg
・ Fluorine-based nonionic surfactant (Dainippon Ink Chemical Co., Ltd.,
Mega Fuck F-177P) 0.02g
-Thermal polymerization inhibitor N-nitrosophenyl hydroxyl 0.02g
・ Colored pigment dispersion 2.0g
(Composition of pigment dispersion)
Composition: Pigment Blue 15: 6 15 parts by mass
Allyl methacrylate / methacrylic acid copolymer 10 parts by mass
(Copolymerization molar ratio 83/17)
15 parts by mass of cyclohexanone
20 parts by mass of methoxypropyl acetate
40 parts by mass of propylene glycol monomethyl ether and 20.0 g of methyl ethyl ketone
・ Propylene glycol monomethyl ether 20.0g
(Preparation 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 such that the dry coating weight was 2 g / m ² and dried at 100 ° C. for 2 minutes.

(Evaluation of photosensitivity and suitability for safelight)
(Photosensitivity evaluation)
A Fuji step guide manufactured by Fuji Photo Film Co., Ltd. (grayscale whose transmission optical density changes discontinuously at ΔD = 0.15) was adhered to the photosensitive material thus obtained, and an optical filter ( Using a xenon lamp through Kenko BP-40), exposure was performed so as to obtain a known exposure energy. As an optical filter, Kenko BP-40 capable of exposure with monochromatic light of 400 nm was used for the purpose of estimating the suitability of exposure to a short-wave semiconductor laser. Thereafter, the film was immersed in a developer having the following composition at 25 ° C. for 10 seconds, developed, and the sensitivity (clear sensitivity) was calculated from the maximum number of steps at which the image was completely removed (Table 2). Here, the clear sensitivity represents the minimum energy required for image formation, and the lower this value, the higher the sensitivity.
(Safelight suitability evaluation)
The emission intensity distribution of a safe light that is generally used was measured, and the position where the emission intensity distribution rises on the short wave side (short wave end) was measured. In addition, the workability under each safelight was evaluated. The results are shown in Table 1.

  Moreover, after exposing the photosensitive material of Examples 1-14 in which the above-mentioned photosensitivity evaluation was carried out under a yellow lamp for 1 hour before exposure, it exposed and developed similarly. At that time, those in which image fogging did not occur were indicated as “○”, and those in which image fogging occurred were indicated as “×” and are shown in Table 2.

  As shown in Table 2, the lithographic printing plate of the present invention has very high sensitivity and exhibits sufficient sensitivity for the scanning exposure method.

  In addition, the initiation system of the present invention is highly sensitive compared to the case where no sensitizing dye is used, and has excellent workability under a yellow light compared to the case where a titanocene compound is used as an activator compound. It has been shown.

(Developer composition)
0.2 g aqueous potassium hydroxide solution having the following composition and pH 12.0
1K potassium silicate 2.4 g
(SiO ₂ / K ₂ O = 1.9)
Compound of formula 1 below 5.0 g
Ethylenediaminetetraacetic acid, 4Na salt
0.1 g
91.3 g of water

[Examples 15 to 19, Comparative Example 7]
A lithographic printing plate was prepared according to the following procedure, and the printing performance was evaluated. The results are shown in Table 3.
"Pretreatment of support"
An aluminum plate made of material 1S having a thickness of 0.3 mm was washed with water after using a No. 8 nylon brush and an 800 mesh Pamiston water suspension to grind the surface. After etching by immersing in 10% by mass sodium hydroxide at 70 ° C. for 60 seconds, washed with running water, neutralized and washed with 20% by mass nitric acid, and then washed with water. Under the condition of V _A = 12.7 V, an electrolytic surface-roughening treatment was performed in a 1% by mass nitric acid aqueous solution using a sine wave alternating waveform current at an anode time electricity of 300 coulomb / dm ² . When the surface roughness was measured, it was 0.45 μm (Ra indication according to JIS B0601).

"Hydrophilic treatment of the support surface"
Said support is 2.5% by mass of No. 3 sodium silicate (SiO ₂ = 28-30%, Na ₂ O = 9-10%, Fe = 0.02% or less), pH = 11.2, It was immersed in an aqueous solution at 70 ° C. for 13 seconds and then washed with water. From the amount of Si element obtained by surface fluorescent X-ray analysis, the amount of surface silicate was determined to be 10 mg / m ² .
"Coating the middle layer"
A coating solution having the composition shown in the following (A) is prepared on the surface of the above-mentioned hydrophilized support so that the coating amount of phenylphosphonic acid is 20 mg / m ^2, and coated with a wheeler under the condition of 180 rpm. Then, it was dried at 80 ° C. for 30 seconds.

(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 solution having the following composition is prepared, applied with a wheeler so that the applied amount is 1.0 to 2.0 g / m ^2, and dried at 100 ° C. for 1 minute. It was.

(Photosensitive solution)
Addition polymerizable compound (compound described in Table 3) 1.5 g
Binder polymer (compound described in Table 3) 1.9 g
Sensitizing dye (compound described in Table 3) 0.1 g
Activator (compound described in Table 3) 0.2g
Co-sensitizer (compound described in Table 3) 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) Thermal polymerization
15 parts by mass of cyclohexanone
20 parts by mass of methoxypropyl acetate
Propylene glycol monomethyl ether 40 parts by mass Thermal polymerization inhibitor (N-nitrosophenylhydroxylamine aluminum salt) 0.01 g
Surfactant (manufactured by Dainippon Ink and Chemicals, Megafac F-177)
0.02g
Methyl ethyl ketone 20.0g
Propylene glycol monomethyl ether 20.0g

"Coating 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 such that the dry coating weight was 2 g / m ² and dried at 100 ° C. for 2 minutes.
"Exposure of planographic printing plate precursor"
Using the lithographic printing plate precursor obtained as described above as a light source, using 400 nm monochromatic light, adjusting the exposure power so that the plate surface exposure energy density is 200 μJ / cm ² , solid image exposure and 175 lines / inch A halftone image exposure of 1 to 99% in 1% increments was performed.
"Development / plate making"
A predetermined developing solution (described in Table 3) and a finisher FP-2W manufactured by Fuji Photo Film Co., Ltd. were charged into an automatic processor LP-850 manufactured by Fuji Photo Film Co., Ltd., respectively, and the developing solution temperature was 30 ° C. and the development time was 18 seconds. The plate exposed under the conditions of the above was developed / plate-making 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. 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 higher 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"
R201 manufactured by Roland was used as the printing machine, and GEOS-G (S) manufactured by Dainippon Ink was used as the ink. The printed matter in the non-image area (unexposed area) was observed to evaluate the stain resistance.

(Addition polymerizable compound in Table 3)
(M-1)
Pentaelsitol tetraacrylate (Shin Nakamura Chemical Co., Ltd .; NK Ester A-TMMT)
(M-2)
Glycerin dimethacrylate hexamethylene diisocyanate urethane prepolymer (Kyoeisha Chemical Co., Ltd .; UA101H)
(Binder polymer in Table 3)
(B-1)
Allyl methacrylate / methacrylic acid / N-isopropylacrylamide (copolymerization molar ratio 67/14/19)
Measured acid value obtained by NaOH titration 1.13 meq / g
Mass average molecular weight determined by GPC measurement 120,000 (B-2)
Allyl methacrylate / methacrylic acid copolymer (copolymerization molar ratio 83/17)
Measured acid value determined by NaOH titration 1.55 meq / g
Mass average molecular weight determined by GPC measurement 125,000 (B-3)
Polyurethane resin 4, 4'-diphenylmethane diisoisocyanate (MDI), which is a polycondensation product of the following diisocyanate and diol
Hexamethylene diisocyanate (HMDI)
Polypropylene glycol, mass average molecular weight 1000 (PPG1000)
2,2-bis (hydroxymethyl) propionic acid (DMPA)
Tetraethylene glycol (TEG)
Copolymerization molar ratio (MDI / HMDI / PPG1000 / DMPA / TEG)
40/10/11/27/12
Measured acid value obtained by NaOH titration 1.07 meq / g
Mass average molecular weight determined by GPC measurement: 43,000

(Developer in Table 3)
(DV-1)
PH 10 aqueous solution monoethanolamine having the following composition 0.1 parts by mass Triethanolamine 1.5 parts by mass Compound of the following formula 2 4.0 parts by mass Compound of the following formula 3 2.5 parts by mass Compound of the following formula 4 2 parts by mass of water 91.7 parts by mass (DV-2)
Aqueous solution of sodium hydrogen carbonate having pH 10 having the following composition 1.2 parts by weight Sodium carbonate 0.8 parts by weight Compound of formula 2 below 3.0 parts by weight Compound of formula 3 below 2.0 parts by weight Compound of formula 4 below 0.2 92.8 parts by mass of water (DV-4)
0.2 g aqueous potassium hydroxide solution having the following composition and pH 12.0
1K potassium silicate 2.4 g
(SiO ₂ / K ₂ O = 1.9)
Compound of formula 1 below 5.0 g
Ethylenediaminetetraacetic acid, 4Na salt
0.1 g
91.3 g of water

(Where R is H or C ₄ H ₉ and n is about 4 (average value).)
As is apparent from Table 3, the lithographic printing plate according to the present invention provides an excellent lithographic printing plate even under conditions capable of making a plate with high productivity by scanning exposure, that is, under very low energy exposure conditions. On the other hand, no practical lithographic printing plate was obtained in Comparative Example 7 which did not use the initiation system of the present invention.

Example 20
A lithographic printing plate precursor was prepared in the same manner as in Examples 1 to 14 except that the starting system was changed to the following composition and the film thickness of the photopolymerization layer was changed to 1.4 g / m ² .
Initiating system Content sensitizing dye in the total solid content of the photopolymerization layer D16 1.4% by mass
Activator A-1 1.5% by mass
Co-sensitizer H5 7.0% by mass
The obtained lithographic printing plate precursor was subjected to scanning exposure using an InGaN semiconductor laser with an oscillation wavelength of 400 nm under the conditions of a beam system on the plate surface of 25 μm and an exposure energy density of 0.2 mJ / cm ² . Next, the plate was heated at 100 ° C. for 10 seconds and then subjected to the development processing described above.

  A lithographic printing plate having a blue image with excellent visibility was obtained. When offset printing was carried out using the obtained plate and a Heidelberg KOR-D machine, 50,000 or more printed matter excellent in image density and stain resistance could be obtained.

Example 21
The plate of Example 20 was stored for 3 days under forced storage conditions of 65% humidity and 45 ° C., and then plate-making and printing were performed in the same manner as in Examples 1-14. Good results similar to Example 20 were obtained.

[Example 22]
A lithographic printing plate precursor was prepared in the same manner as in Examples 1 to 14, except that the starting system was changed to the following composition and the film thickness of the photopolymerization layer was changed to 2.0 g / m ² .
Initiating system Content sensitizing dye in the total solid content of the photopolymerization layer D8 1.4% by mass
Activator A-1 1.5% by mass
Co-sensitizer H5 5.0% by mass
The obtained lithographic printing plate precursor was subjected to scanning exposure using an InGaN semiconductor laser with an oscillation wavelength of 400 nm under the conditions of a beam system on the plate surface of 25 μm and an exposure energy density of 0.15 mJ / cm ² . Next, the plate was heated at 100 ° C. for 10 seconds and then subjected to the development processing described above. A lithographic printing plate having a blue image with excellent visibility was obtained. The obtained plate is further heated at 300 ° C. for 5 minutes and then subjected to offset printing using a Heidelberg KOR-D machine. As a result, it is possible to obtain 200,000 or more printed materials having excellent image density and stain resistance. did it.

Example 23
The plate of Example 22 was exposed to a yellow lamp for 1 hour before exposure, and plate making and printing were carried out in the same manner. Good results exactly the same as in Example 22 were obtained.

[Comparative Example 8]
A lithographic printing plate precursor was prepared in the same manner as in Example 20 except that the sensitizing dye was changed from D16 (maximum absorption wavelength 416 nm) to DR-2 (maximum absorption wavelength 500 nm) in Example 20. When the obtained lithographic printing plate precursor was subjected to plate making using an InGaN-based semiconductor laser having an oscillation wavelength of 400 nm in the same manner as in Example 20, the result was an image flow. Further, the obtained lithographic printing plate precursor was exposed to a yellow lamp for 1 hour before exposure in the same manner as in Examples 1 to 14 and then subjected to plate making and printing in exactly the same manner. Occurred.

  In addition, the sensitizing dye in a present Example is what was illustrated in this specification, and the structure of another compound is as follows.

[Comparative Example 9]
In Example 20, except that the laser was changed to FD-YAG (532 nm), an image having a clear sensitivity of 1.8 mJ / cm 2 was obtained when the plate was made in the same manner as in Example 20. However, when the obtained lithographic printing plate precursor was exposed to a yellow light for 30 minutes before exposure for 30 minutes in the same manner as in Example 19, plate making and printing were carried out in exactly the same manner. .

Claims (3)

(I) a sensitizing dye represented by the following general formula (1);
(Ii) an activator compound that undergoes a chemical change by interaction with light absorption of a sensitizing dye represented by the following general formula (1) to generate at least one of a radical and an acid;
(Iii) A photosensitive composition comprising a compound that reacts with at least one of a radical and an acid and whose physical or chemical properties change irreversibly.

(In the formula, X represents an oxygen atom or a sulfur atom, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ are each independently a hydrogen atom or a monovalent atom. Represents a nonmetallic atomic group.)   The photosensitive composition according to claim 1, wherein the activator compound (ii) contains at least one acylphosphine compound.   An image recording material comprising the support and the photosensitive composition according to claim 1 or 2 provided thereon.