JP2005060531A - Alkali-soluble polymer, method for producing the same, polymerizable composition containing the same and image-recording material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymerizable composition polymerized and cured by exposure to a laser light or the like in high sensitivity to provide an excellent cured film, and useful for a recording layer of a negative plate of a negative lithographic plate; and to provide a new alkali-soluble polymer suitably usable for the polymerizable composition, and a method for producing the polymer. <P>SOLUTION: The alkali-soluble polymer including a crosslinked structure in the inside has the intramolecular crosslinked structure formed by a bifunctional crosslinking agent having two radical-polymerizable groups in the molecule. The polymer can be produced by starting and carrying out a radical polymerization reaction in the presence of (i) the bifunctional crosslinking agent having the two radical-polymerizable groups in the molecule, (ii) a monofunctional radical-polymerizable monomer, (iii) a polymerization initiator and (iv) an organic solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel alkali-soluble polymer, a method for producing the same, a polymerizable composition using the same, and an image recording material using the polymerizable composition as a photosensitive layer. The present invention relates to an image recording material, a polymerizable composition useful as a photosensitive layer thereof, a novel alkali-soluble polymer that can be suitably used for the polymerizable composition, and a method for producing the same.

Conventionally, as a lithographic printing plate precursor, one having a constitution in which a lipophilic photosensitive resin layer is provided on a hydrophilic support is widely used. As the plate making method, usually, a method of obtaining a desired printing plate by dissolving and removing a non-image portion after mask exposure (surface exposure) through a lithographic film has been used.
In recent years, digitization techniques that electronically process, store, and output image information using a computer have become widespread. Various new image output methods corresponding to such digitization techniques have come into practical use. As a result, computer-to-plate (CTP) technology that scans highly directional light such as laser light according to digitized image information and directly produces a printing plate without going through a lithographic film is eagerly desired. Obtaining a lithographic printing plate precursor adapted to this is an important technical issue.

  As such a lithographic printing plate precursor capable of scanning exposure, an oleophilic photosensitive resin layer containing a photosensitive compound capable of generating active species such as radicals and bronzed acids by laser exposure on a hydrophilic support (hereinafter referred to as “lithographic printing plate precursor”) , Also referred to as “photosensitive layer”) has been proposed and is already on the market. This lithographic printing plate precursor is laser-scanned based on digital information to generate active species, which causes physical or chemical changes in the photosensitive layer to insolubilize it, followed by development processing, thereby developing a negative lithographic printing plate Can be obtained.

  In particular, a photopolymerization type photosensitive layer (recording layer) containing a photopolymerization initiator excellent in photosensitive speed, an addition-polymerizable ethylenically unsaturated compound, and a binder polymer soluble in an alkali developer on a hydrophilic support. ) And, if necessary, a lithographic printing plate precursor provided with an oxygen-blocking protective layer is excellent in productivity, is easy to develop, and has good printing performance and desirable printing performance. A printing plate having

  Conventionally, organic polymer polymers that can be developed with an alkali such as a methacrylic acid copolymer and an acrylic acid copolymer have been used as the binder polymer constituting the recording layer (see, for example, Patent Documents 1 and 2). .)

When such an alkali-soluble polymer binder is used, a method of reducing the amount of alkali-soluble groups is usually employed in order to impart high printing durability. However, in this case, developability tends to deteriorate.
On the other hand, as an attempt to increase the sensitivity, a technique for introducing a radical polymerizable group into the alkali-soluble binder polymer itself has been proposed (see, for example, Patent Document 3). By imparting a radical polymerizable group to the binder polymer, the binder as a polymer can directly contribute to crosslinking, so that the crosslinking reaction is increased due to the molecular weight effect, which can certainly contribute to higher sensitivity. However, the introduction of the polymerizable group makes the polymer, and the polymerizable composition containing it thermally unstable, resulting in deterioration of storage stability due to the high gel efficiency of the crosslinkable binder, and pinching between image thin line portions. As a result, problems such as poor cuts of fine lines due to a decrease in developability of the non-image portion have occurred, and there is a concern about lowering the image quality. This is a general dilemma when using a polymer having a reactive functional group such as a polymerizable group or a crosslinkable group, and it satisfies all of high sensitivity, excellent curability, and high image quality. There has been a need for such a polymerizable composition.
As another attempt to increase sensitivity, the applicant of the present application has proposed a technique of using an alkali-soluble binder polymer having an unsaturated group introduced in the side chain in a negative image recording material (see, for example, Patent Document 4). .) As a result, a recording material excellent in sensitivity and storage stability was obtained. On the other hand, further improvements have been studied from the viewpoint of achieving both image quality and printing durability.
Japanese Patent Publication No.54-34327 Japanese Examined Patent Publication No. 58-12777 JP 2000-187322 A JP-A-2002-62648

  The object of the present invention in consideration of the above-described conventional problems is a polymerizable composition that can be polymerized and cured with high sensitivity by exposure to laser light or the like and can form an excellent cured film, and is suitable for the polymerizable composition. It is an object of the present invention to provide a novel alkali-soluble polymer that can be used in the present invention and a method for producing the same. Further, another object of the present invention is to provide a polymerizable composition having good dot stability such as halftone dots and fine lines and capable of forming a high-quality image, and having good storage stability, and an alkali-soluble polymer that can be suitably used therefor. It is also intended to provide a manufacturing method thereof.

  As a result of intensive studies to achieve the above object, the present inventors can achieve the above object by introducing a cross-linked structure in the polymer binder molecule having an alkali-soluble group in the side chain, and The inventors have found a simple method for producing an alkali-soluble polymer having such an intramolecular crosslinked structure, and have completed the present invention.

  That is, the novel alkali-soluble polymer of the present invention is characterized by having an intramolecular crosslinking structure formed by a bifunctional crosslinking agent having two radically polymerizable groups in the molecule. Hereinafter, an alkali-soluble polymer having an intramolecular cross-linked structure formed by such a bifunctional cross-linking agent will be referred to as a cross-linked structure-containing alkali-soluble polymer. As the intramolecular crosslinking structure, those having a structure represented by the following general formula (I-1) are preferable.

In general formula (I-1), Q represents a hydrocarbon linking group, and the linking group structure may have —O— or —CO ₂ —. X represents N—R ′, an O atom, or an S atom, where R ′ represents a hydrogen atom or an alkyl group.
Such an alkali-soluble polymer having an intramolecular crosslinking structure comprises i) a bifunctional crosslinking agent having two radical polymerizable groups in the molecule, ii) a monofunctional radical polymerizable monomer, and iii) polymerization. It can be produced by initiating and proceeding a radical polymerization reaction in the presence of an initiator and iv) an organic solvent.
Here, the polymer having an intramolecular crosslinking structure produced by the radical polymerization reaction may be further modified with an acid or a base.

Moreover, the polymerizable composition concerning Claim 3 of this invention contains the said crosslinked structure inclusion alkali-soluble polymer, It is characterized by the above-mentioned. Such a polymerizable composition is useful as a photosensitive layer of a negative type image recording material.
The image recording material according to claim 4 of the present invention is characterized in that a photosensitive layer containing the polymerizable composition of the present invention is provided on a support.

The alkali-soluble polymer of the present invention has a crosslinked structure in the molecule, but the degree of crosslinking does not impair at least the alkali solubility of the polymer itself. Moreover, it is preferable that it is a compound containing at least 1 sort (s) selected from the group which consists of following (1)-(6) as an alkali-soluble group in a molecule | numerator.
(1) Phenolic hydroxyl group (2) Sulfonamide group (3) Substituted sulfonamide acid group (4) Carboxylic acid group (5) Sulfonic acid group (6) Phosphoric acid group

  The alkali-soluble polymer of the present invention achieves high sensitivity and high image quality-high printing durability and storage stability by introducing a crosslinked structure in the polymer binder molecule having an alkali-soluble group in the side chain in advance. ing. Usually, when a crosslinked structure is introduced into a polymer, it tends to be in a gel state, and the solubility in an organic solvent or alkaline water is generally significantly reduced. On the other hand, it is particularly important in the present invention that a cross-linking agent having a specific structure is allowed to coexist in a minute amount at the time of polymerization, so that it has a partial cross-linking structure in the molecule without impairing solubility in organic solvents or alkaline water. The polymer was obtained. Such a partial cross-linked structure in the polymer can be confirmed by the presence of two or more peaks in the polymer distribution according to the profile of gel permeation chromatography (GPC). That is, the GPC profile of a polymer that does not have a crosslinked structure in the molecule has only one peak.

Although the mechanism of action of the present invention is not clear, it is presumed as follows.
The novel alkali-soluble polymer of the present invention is completely different from the conventional linear polymer in that the cross-linked structure pre-existing in the polymer molecule is different from the case where the polymerizable monomer is polymerized alone by light or heat in the exposed area. In addition, the degree of gelation is greatly increased, and a cured film is rapidly formed. On the other hand, in the non-image area (unexposed area), the alkali solubility caused by the acid group present in the molecule is not impaired, so that it is quickly developed and removed in the non-image area of a small area such as between fine lines. However, it is considered that the high developability can be maintained.
In addition, it is considered that a tough crosslinked film was formed by the synergistic effect of the crosslinked structure previously introduced into the polymer molecule and the new crosslinked structure (gelation structure) formed by polymerization, leading to high printing durability. ing.
In addition, since the mobility of the polymer is reduced due to the intramolecular cross-linking structure, the storage stability is improved, and it is considered that the polymer is stable unless high energy such as light or high heat is applied. ing.

  The polymerizable composition containing the crosslinked structure-encapsulating alkali-soluble polymer of the present invention is particularly suitably used as an image recording layer in a direct lithographic printing plate compatible with a heat mode laser having a laser beam wavelength of 800 nm or more. . The reason is that image recording materials that support heat mode by infrared laser exposure convert light into heat and generate radicals by that heat, so both storage stability (thermal stability) and sensitivity are compatible with light. There is a stricter situation than the photon mode sensitive material that generates the. However, the polymerizable composition using the alkali-soluble polymer of the present invention satisfies both of them because it has good storage stability due to its structure and can be cured with high sensitivity. Furthermore, unlike photon mode-compatible image forming materials that are polymerized and cured by light of a short wavelength, the heat mode sensitive material has a problem that curing due to a radical reaction in the vicinity of the support is insufficient due to thermal diffusion. It can be seen that the polymerizable composition of the present invention is useful from the viewpoint that a tough cured film property is formed in the image area as in the polymerizable composition of the present invention.

The novel alkali-soluble polymer of the present invention has a crosslinked structure in the molecule, has good storage stability, and can form a cured film having excellent film properties. Moreover, according to the method for producing an alkali-soluble polymer of the present invention, such a crosslinked structure-containing alkali-soluble polymer can be easily synthesized.
The polymerizable composition of the present invention is characterized in that it contains the above-mentioned crosslinked structure-encapsulating alkali-soluble polymer, has good storage stability, is highly sensitive to polymerization and curing by exposure to laser light, etc., and is excellent. A cured film can be formed and is useful for a recording layer of a negative type image recording material. In addition, since the image recording material using such a polymerizable composition can maintain excellent alkali solubility in the unexposed area, the dots and fine lines are cut well, and a high-quality image can be formed. Can do.

Hereinafter, the present invention will be described in detail.
[Crosslinked structure-containing alkali-soluble polymer]
The alkali-soluble polymer of the present invention is characterized in that it has an intramolecular cross-linked structure formed by a bifunctional cross-linking agent having two radical polymerizable groups in the molecule.
Hereinafter, a preferred main chain structure of the crosslinked structure-encapsulating alkali-soluble polymer of the present invention, an alkali-soluble group that can be introduced, a radically polymerizable group, and the like will be sequentially described.

The alkali-soluble polymer of the present invention has a structural unit containing an alkali-soluble group in the molecule, and an intramolecular crosslinked structure formed by a bifunctional crosslinking agent as described in detail later. As long as it has the range which does not inhibit alkali solubility of this, there will be no restriction | limiting in particular, As a structural unit of an alkali-soluble polymer, it can comprise by combining well-known things arbitrarily.
Preferably, an organic polymer that is soluble or swellable in water or weak alkaline water that enables water development or weak alkaline water development is selected.

  The main chain structure of the alkali-soluble polymer is not particularly limited, but preferred polymer main chains from the viewpoint of effects include polyurethane, polyamide, polyester, polyvinyl, polystyrene, and poly (meth) acrylic polymers. More preferred are polystyrene and poly (meth) acrylic polymers.

The structural unit having an alkali-soluble group in the polymer is at least one alkali-soluble group (acidic group) selected from the group consisting of the following (1) to (6) from the viewpoint of solubility in an alkali developer. Containing structural units are preferred.
The alkali-soluble group (acidic group) contained in the structural unit constituting the alkali-soluble polymer of the present invention is an embodiment in which an alkali-soluble group is directly bonded to the main chain structure, and the alkali-soluble group is connected to the main chain structure via a linking group. Any of the combined aspects may be used.

  Since the polymerizable composition of the present invention to be described later uses such an alkali-soluble polymer as a main component, it exhibits a property of being dissolved in contact with an alkaline developer in an unexposed portion.

-Alkali-soluble group-
The suitable aspect of the alkali-soluble group contained in the structural unit which comprises the polymer of this invention is demonstrated.
The polymer of the present invention preferably has a structural unit containing at least one alkali-soluble group selected from the group consisting of the following (1) to (6) from the viewpoint of solubility in an alkaline developer.

(1) Phenolic hydroxyl group (-Ar-OH)
(2) Sulfonamide group (—SO ₂ NH—R)
(3) Substituted sulfonamide acid group (hereinafter referred to as “active imide group”)
[—SO ₂ NHCOR, —SO ₂ NHSO ₂ R, —CONHSO ₂ R]
(4) Carboxylic acid group (—CO ₂ H)
(5) Sulfonic acid group (—SO ₃ H)
(6) Phosphate group (—OPO ₃ H ₂ )

  In the above (1) to (6), Ar represents a divalent aryl linking group which may have a substituent, and R represents a hydrogen atom or a hydrocarbon group which may have a substituent. .

  Among the structural units having an alkali-soluble group selected from the above (1) to (6), (1) a structural unit having a phenolic hydroxyl group, (2) a sulfonamide group, and (4) a carboxylic acid group is preferable. (4) An alkali-soluble polymer composed of a structural unit having a carboxylic acid group as an alkali-soluble group and another structural unit is most preferable from the viewpoint of sufficiently securing solubility, swelling property and printing durability.

Examples of the structural unit having an alkali-soluble group selected from the above (1) to (6) include the following.
(1) The alkali-soluble structural unit having a phenolic hydroxyl group includes a structural unit having a hydroxyaryl group in the side chain.
Moreover, as a structural unit which has a hydroxyaryl group in a side chain, what contains any one of the structural units represented by the following general formula (a)-(d) can be mentioned, for example.

In the general formulas (a) to (d), R ¹¹ represents a hydrogen atom or a methyl group. R ¹² and R ¹³ may be the same or different and each represents a hydrogen atom, a halogen atom, a hydrocarbon group having 10 or less carbon atoms, an alkoxy group having 10 or less carbon atoms, or an aryloxy group having 10 or less carbon atoms. R ¹² and R ¹³ may be bonded and condensed to form a benzene ring or a cyclohexane ring. R ¹⁴ represents a single bond or a divalent hydrocarbon group having 20 or less carbon atoms. R ¹⁵ represents a single bond or a divalent hydrocarbon group having 20 or less carbon atoms. R ¹⁶ represents a single bond or a divalent hydrocarbon group having 10 or less carbon atoms. X ¹ represents a single bond, an ether bond, a thioether bond, an ester bond or an amide bond. p represents an integer of 1 to 4. q and r each independently represents an integer of 0 to 3.

  (2) Examples of the alkali-soluble structural unit having a sulfonamide group include a minimum structural unit derived from a compound having a sulfonamide group. Examples of such compounds include structural units each having at least one sulfonamide group in which at least one hydrogen atom is bonded to a nitrogen atom and one or more polymerizable unsaturated groups. Among them, structural units having an acryloyl group, an allyl group, or a vinyloxy group, and a substituted or mono-substituted aminosulfonyl group or a substituted sulfonylimino group are preferable. For example, the structural units are represented by the following general formulas (i) to (v). And a structural unit derived from the compound to be obtained.

In general formula (i) to general formula (v), X ¹ and X ² each independently represent —O— or —NR ⁷ . R ¹ and R ⁴ each independently represents a hydrogen atom or —CH ₃ . R ² , R ⁵ , R ⁹ , R ¹² , and R ¹⁶ each independently represent a C 1-12 alkylene group, cycloalkylene group, arylene group, or aralkylene group that may have a substituent. . R ³ , R ⁷ and R ¹³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group. R ⁶ and R ¹⁷ each independently represents a C 1-12 alkyl group, cycloalkyl group, aryl group or aralkyl group which may have a substituent. R ⁸ , R ¹⁰ and R ¹⁴ each independently represent a hydrogen atom or —CH ₃ . R ¹¹ and R ¹⁵ each independently represent a C 1-12 alkylene group, cycloalkylene group, arylene group or aralkylene group which may have a single bond or a substituent. Y ¹ and Y ² each independently represent a single bond or CO.

  (3) Examples of the alkali-soluble structural unit having an active imide group include a minimum structural unit derived from a compound having an active imide group. Examples of the structural unit as described above include a structural unit having at least one active imide group represented by the following structural formula and one or more polymerizable unsaturated groups.

(4) Examples of the alkali-soluble structural unit having a carboxylic acid group include a minimum structural unit derived from a compound having at least one carboxylic acid group and polymerizable unsaturated group in the molecule. .
(5) Examples of the alkali-soluble structural unit having a sulfonic acid group include a minimum structural unit derived from a compound having one or more sulfonic acid groups and polymerizable unsaturated groups in the molecule. .
(6) Examples of the alkali-soluble structural unit having a phosphoric acid group include a minimum structural unit derived from a compound having at least one phosphoric acid group and a polymerizable unsaturated group in the molecule. .

  The minimum structural unit having an acidic group selected from the above (1) to (6), which constitutes the alkali-soluble polymer of the present invention, does not have to be only one kind, and the minimum structural unit having the same acidic group Two or more kinds, or those obtained by copolymerizing two or more kinds of minimum structural units having different acidic groups can also be used. In the present invention, the structural unit having an alkali-soluble group is preferably block-bonded from the viewpoint of the effect. From this meaning, when a plurality of structural units having an acidic group are included, each structural unit is a random bond. However, the entire structural unit having an acidic group needs to be block-bonded.

  The amount of the structural unit having an alkali-soluble group in the polymer is not particularly limited as long as the polymer can be dissolved in an alkaline developer having a pH of 10 to 13 due to the presence of the alkali-soluble group.

  As an aspect which introduce | transduces an alkali-soluble group into the polymer of this invention, the aspect which contains the structural unit (repeating unit) represented by following General formula (1) in a polymer is the most preferable.

In general formula (1), R ¹ represents a hydrogen atom or a methyl group. , R ² represents a linking group composed of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom and having 2 to 30 atoms excluding substituents. A represents an oxygen atom or —NR ³ —, and R ³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. n represents an integer of 1 to 5.

The general formula (1) will be described in detail.
R ¹ in the general formula (1) represents a hydrogen atom or a methyl group, and a methyl group is particularly preferable.

The linking group represented by R ² in the general formula (1) is composed of a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom, and the number of atoms excluding the substituent is 2 to 30. is there. Specific examples include alkylene, substituted alkylene, arylene, substituted arylene, and the like, and a structure in which a plurality of these divalent groups are linked by an amide bond or an ester bond may be used.
Examples of the linking group having a chain structure include ethylene and propylene. A structure in which these alkylenes are linked via an ester bond can also be exemplified as a preferable example.

Among these, the linking group represented by R ² in the general formula (1) is an (n + 1) -valent hydrocarbon group having an aliphatic cyclic structure and a chain structure having 3 to 30 carbon atoms. More preferred. More specifically, a compound having an aliphatic cyclic structure such as cyclopropane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, dicyclohexyl, tercyclohexyl, norbornane and the like, which may be substituted by one or more arbitrary substituents Or (n + 1) -valent hydrocarbon groups by removing (n + 1) hydrogen atoms on any carbon atom constituting a compound having an aliphatic chain structure having 5 to 20 atoms. it can.

  One or more carbon atoms of the compound constituting the aliphatic cyclic structure and the chain structure may be substituted with one or more heteroatoms selected from a nitrogen atom, an oxygen atom, and a sulfur atom.

Examples of the substituent that can be introduced into the linking group represented by R ² include monovalent nonmetallic atomic groups other than hydrogen, such as halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups. Group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N- Diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy , Arylsulfoxy group, an acylthio group, an acylamino group, N- alkylacylamino group, N- arylacylamino group, a ureido group,

N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido Group, N-arylureido group, N'-alkyl-N-alkylureido group, N'-alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'- Dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′- Diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-aryluree De group, an alkoxycarbonylamino group, aryloxycarbonylamino group,

N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl Group, carboxyl group and its conjugate base group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N- alkyl -N- arylcarbamoyl group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugated base group, alkoxy sulfonyl group, aryloxy sulfonyl group Sulfinamoyl group, N- alkylsulfinamoyl group, N, N- dialkyl sulfinamoyl group, N- aryl sulfinamoyl group,

N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and its conjugate base group, N-alkylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ (Alkyl)) and its conjugate base group, N-arylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ (aryl)) and its conjugate base group, N-alkylsulfonylcarbamoyl group (—CONHSO ₂ (alkyl)) and its conjugated base group, N- aryl sulfonyl carbamoyl group (-CONHSO ₂ (aryl) And a conjugated base group, an alkoxysilyl group (-Si (Oalkyl) _3), aryloxy silyl group (-Si (Oaryl) _3),

Hydroxysilyl group (—Si (OH) ₃ ) and its conjugate base group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group, dialkylphosphono group (—PO ₃ (alkyl) ₂ ), diarylphosphono group (—PO ₃ (aryl) ₂ ), alkylarylphosphono group (—PO ₃ (alkyl) (aryl)), monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group, monoarylphospho Group (—PO ₃ H (aryl)) and its conjugate base group, phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group, dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphono oxy group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphono group _{(-OPO 3 (alkyl) (aryl} )), monoalkyl phosphonates Oxy group (-OPO ₃ H (alkyl)) and its conjugated base group, monoarylphosphono group (-OPO ₃ H (aryl)) and its conjugated base group,

A cyano group, a nitro group, a dialkylboryl group (—B (alkyl) ₂ ), a diarylboryl group (—B (aryl) ₂ ), an alkylarylboryl group (—B (alkyl) (aryl)), a dihydroxyboryl group (— B (OH) ₂ ) and its conjugate base group, alkylhydroxyboryl group (-B (alkyl) (OH)) and its conjugate base group, arylhydroxyboryl group (-B (aryl) (OH)) and its conjugate base Group, aryl group, alkenyl group and alkynyl group.

  Among the above-mentioned substances, hydrophobic substituents such as halogen atoms, hydrocarbon groups (alkyl groups, aryl groups, alkenyl groups, alkynyl groups), alkoxy groups, and aryloxy groups are more preferable because they tend to improve printing durability. In particular, when the cyclic structure is a 6-membered or less monocyclic aliphatic hydrocarbon such as cyclopentane or cyclohexane, it preferably has such a hydrophobic substituent. If possible, these substituents may be bonded to each other or with a substituted hydrocarbon group to form a ring, and the substituent may be further substituted.

In General Formula (1), A represents an oxygen atom or —NR ³ —, and R ³ in the case where A is —NR ³ — represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. . Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ³ include an alkyl group, an aryl group, an alkenyl group, and an alkynyl group.
Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, isopropyl group, isobutyl group, sec-butyl group, 1 carbon number such as tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-norbornyl group Up to 10 linear, branched or cyclic alkyl groups.
Specific examples of the aryl group include carbon having one heteroatom selected from the group consisting of an aryl group having 1 to 10 carbon atoms such as a phenyl group, a naphthyl group, and an indenyl group, a nitrogen atom, an oxygen atom, and a sulfur atom. Examples include heteroaryl groups of 1 to 10, such as furyl, thienyl, pyrrolyl, pyridyl, and quinolyl groups.
Specific examples of the alkenyl group include those having 1 to 10 carbon atoms such as vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group, 1-cyclohexenyl group and the like. A linear, branched, or cyclic alkenyl group is mentioned.
Specific examples of the alkynyl group include alkynyl groups having 1 to 10 carbon atoms such as ethynyl group, 1-propynyl group, 1-butynyl group, and 1-octynyl group. The substituent that R ³ may have is the same as those exemplified as the substituent that R ² can introduce. However, the carbon number of R < ³ > is 1-10 including the carbon number of a substituent.

A in the general formula (1) is preferably an oxygen atom or —NH— because synthesis is easy.
N in the general formula (1) represents an integer of 1 to 5, and is preferably 1 from the viewpoint of printing durability.

(Radical polymerizable group)
The alkali-soluble polymer of the present invention preferably has a radical polymerizable group. The radical polymerizable group may be present in the structural unit having the alkali-soluble group, but may be included in another structural unit used together. As the structural unit that can be used in combination, known monomers can be used without particular limitation as long as they are radically polymerizable monomers. Specific examples include monomers described in “Polymer Data Handbook -Basic Edition” (edited by the Society of Polymer Science, Bafukan, 1986), which are structural units having at least one radical polymerizable group in the side chain. Preferably there is.
The radically polymerizable group contained in the alkali-soluble polymer of the present invention is not particularly limited as long as it is a radically polymerizable group. Preferred examples include an α-substituted methylacryl group [—OC (═O) —C ( —CH ₂ Z) ═CH ₂ (Z = hydrocarbon group starting from a hetero atom)], acrylic group, methacryl group, allyl group, and styryl group. Among these, particularly preferred are acrylic group and methacryl group. Can be mentioned.
The content of radical polymerizable groups (content of unsaturated double bonds capable of radical polymerization by iodine titration) is preferably 0.1 per 1 g of the polymer as the total amount of radical polymerizable groups in the alkali-soluble polymer. ˜10.0 mmol, more preferably 1.0 to 7.0 mmol, most preferably 2.0 to 6.0 mmol. As the content of the radical polymerizable group in the whole polymer decreases, the curability tends to be low and the sensitivity tends to be low, and the storage stability tends to decrease as more unsaturated bonds are present.

  In the alkali-soluble polymer of the present invention, in addition to the structural unit containing the alkali-soluble group and the structural unit having the radical polymerizable group, in the range not impairing the effects of the present invention, for various purposes such as improvement of film properties. Other structural units described later may be copolymerized.

Other structural units that can be used here include, for example, acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, Examples include structural units derived from known monomers such as maleic imide.
Examples of the acrylic esters include methyl acrylate, ethyl acrylate, (n- or i-) propyl acrylate, (n-, i-, sec- or t-) butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, Dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 5-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, methoxybenzyl Acrylate, chlorobenzyl acrylate, 2- (p-hydroxyphenyl) ethyl acrylate, full-free Acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, chlorophenyl acrylate, sulfamoylphenyl acrylate and the like.

Examples of the methacrylic acid esters include methyl methacrylate, ethyl methacrylate, (n- or i-) propyl methacrylate, (n-, i-, sec- or t-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate, Dodecyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, methoxybenzyl methacrylate, chloro Benzyl methacrylate, 2- (p-hydroxyphenyl) ethyl methacrylate Rate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate and the like.
Examples of the acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, and N-tolylacrylamide. N- (p-hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl) acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-N- Examples include phenylacrylamide, N-hydroxyethyl-N-methylacrylamide, and the like.

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

Examples of the vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate, and the like.
Examples of the styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, propyl styrene, cyclohexyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, methoxy styrene, and dimethoxy styrene. Chlorostyrene, dichlorostyrene, bromostyrene, iodostyrene, fluorostyrene, carboxystyrene and the like.
Among these monomers, acrylic acid esters having 20 or less carbon atoms, methacrylic acid esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, and acrylonitrile are preferable.

  The crosslinked structure-encapsulating alkali-soluble polymer of the present invention can be synthesized by adding a bifunctional crosslinking agent having two radical polymerizable groups in the molecule at the time of polymerization and using a known method. Here, as a bifunctional crosslinking agent added, the crosslinking agent represented by the following general formula (I) is mentioned.

In the above formula, R represents a hydrogen atom or an alkyl group. Q represents a hydrocarbon linking group, and may have —O— or —CO ₂ — in the linking group structure. X represents N—R ′, an O atom, or an S atom, where R ′ represents a hydrogen atom or an alkyl group.
Here, when R or R ′ represents an alkyl group, an alkyl group having 1 to 12 carbon atoms is preferable. The alkyl group may be linear, branched or cyclic, but is preferably a linear alkyl group.

Q is not particularly limited as long as it is a divalent hydrocarbon linking group, and may have at least one of —O— and —CO ₂ — at the terminal or in the middle thereof. The hydrocarbon linking group may be substituted with a monovalent hydrocarbon group or may have a ring structure. Q is preferably an alkylene group from the viewpoint of alkali solubility.
Specific examples of —X— include —NH—, —N (CH ₃ ) —, —N (C ₂ H ₅ ) —, —O—, —S—, etc., preferably —O— -.

  Specific examples (I-1 to I-97) of the crosslinking agent represented by the general formula (I) that can be suitably used in synthesizing the alkali-soluble polymer of the present invention are represented by R, X in the general formula (I). The structure of Q is shown below, but the present invention is not limited thereto.

  In producing the alkali-soluble polymer of the present invention, the addition amount of this bifunctional crosslinking agent during polymerization is from the viewpoint of coexistence of the film strength (printing durability) of the polymer obtained and alkali-solubility (image quality). It is preferably in the range of 0.01 to 5.0% by mass of the total polymerizable monomer including the bifunctional crosslinking agent, more preferably in the range of 0.01 to 3.0% by mass, more preferably 0.1 It is the range of -2.0 mass%, Most preferably, it is the range of 0.1-1.0 mass%.

  The method for producing an alkali-soluble polymer of the present invention can be carried out in the same manner as in the usual method for synthesizing an alkali-soluble polymer, except that the bifunctional crosslinking agent is added in a preferred amount in the polymerization reaction. That is, i) a bifunctional crosslinker having two radically polymerizable groups in the molecule, preferably a crosslinker represented by the general formula (I), and a general-purpose compound generally used in the production of polymers. ii) A monofunctional radically polymerizable monomer and iii) a polymerization initiator are dissolved and dispersed in an organic solvent so that the concentration of all components (solid content) is 30% by mass or less, and polymerization is performed. A polymer having an intramolecular cross-linked structure can be generated by causing and progressing a polymerization reaction between the polymerizable monomers or between the polymerizable monomer and the cross-linking agent by radicals generated from the initiator.

In the synthesis of the alkali-soluble polymer, i) a bifunctional crosslinking agent having two radically polymerizable groups in the molecule is 0.01 to 5.0% by mass with respect to the total polymerizable monomer, and ii) monofunctionality. The radical polymerizable monomer 95.00 to 99.96% by mass and iii) 0.03 to 5.0% by mass of the polymerization initiator may be added to iv) the organic solvent. v) From the viewpoint of preventing gelation during the reaction, the organic solvent is preferably used in a range where the solid concentration is preferably 20% by mass or less, more preferably 10 to 15% by mass.
The reaction temperature is in the range of 70 to 90 ° C, preferably in the range of 80 to 90 ° C, and the reaction time is preferably 2 to 5 hours, and more preferably 2 to 3 hours.

The polymerizable monomers used in this reaction may be those described above. Examples of the iii) polymerization initiator used for polymer polymerization include azo compounds and peroxides that are generally used as radical initiators.
Examples of the organic solvent used in the polymerization reaction include N ′, N-dimethylacetamide, dimethyl sulfoxide, alcohols having a boiling point of 50 ° C. or higher, ketones having a boiling point of 50 ° C. or higher, acetonitrile, tetrahydrofuran, and the like. .

The polymer having an intramolecular cross-linked structure thus obtained can be further modified with an acid or a base, depending on the purpose.
Examples of the acid used for the modification include hydrochloric acid, naphthalenesulfonic acid, acetic acid, etc., and these may be added and stirred for neutralization. By performing this treatment, a polymer suitable for use in the recording layer of a lithographic printing plate can be obtained.
Examples of the base used for modification include triethylamine, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU), DABCO, sodium hydroxide, potassium hydroxide, and the like. What is necessary is just to neutralize. By performing this treatment, a polymer suitable for use in the recording layer of a lithographic printing plate can be obtained.

  The presence of the partially cross-linked structure in the alkali-soluble polymer of the present invention thus produced is due to the presence of two or more peaks in the polymer distribution according to the gel permeation chromatography (GPC) profile as described above. This can be confirmed.

Hereinafter, other preferred physical properties of the crosslinked structure-encapsulating alkali-soluble polymer of the present invention will be described.
As the acid value (mega / g) of the polymer of the present invention, for example, when a polymerizable composition containing this polymer is used for a recording layer of a lithographic printing plate precursor, its developability, printing durability, and ink setting From a viewpoint of property, Preferably it is 0.01-10.00, More preferably, it is 0.1-7.0, Most preferably, it is 0.2-5.0.

  Similarly, the weight average molecular weight of the alkali-soluble polymer of the present invention is appropriately determined from the viewpoint of the intended use of the polymerizable composition, specifically, for example, from the viewpoints of image formability and printing durability. Usually, when the molecular weight is increased, the film property is improved and the printing durability when used in the recording layer is excellent, but the image forming property due to polymerization and curing reaction tends to deteriorate. On the contrary, when the molecular weight is low, the image forming property is improved, but the film property, that is, the printing durability tends to be lowered. The weight average molecular weight of the alkali-soluble polymer encapsulating the crosslinked structure of the present invention is appropriately determined from the viewpoint of image formability and printing durability. Usually, when the molecular weight increases, the printing durability is excellent, but the image formability tends to deteriorate. On the other hand, if it is low, the image forming property is improved, but the printing durability is lowered. The molecular weight is preferably in the range of 2,000 to 1,000,000, more preferably 5,000 to 500,000, and still more preferably 10,000 to 300,000.

  The glass transition point (Tg) of the crosslinked structure-encapsulating alkali-soluble polymer of the present invention is preferably 0 to 300 ° C., more preferably 20 to 250 ° C., and most preferably 50 to 200 ° C. from the viewpoints of sensitivity and printing durability. is there. As Tg increases, radical mobility in the composition tends to decrease, and when it is too high, there is a concern that the curing reaction will not proceed sufficiently, and the sensitivity of curing when used as a polymerizable composition decreases. Tend to.

In the following, the structure [(P-1) to (P-52)] of a crosslinked structure-encapsulating alkali-soluble polymer suitable in the present invention, its weight average molecular weight and degree of dispersion, and bifunctional crosslinking added during polymerization Although illustrated with an agent, this invention is not restrict | limited to these. The amount of the crosslinking agent added during the polymerization of these polymers was 0.5 mol% with respect to the total monomers.
In the right column of Table 1 to Table 8 (described as GPC peak), the number of peaks of the polymer distribution confirmed by the gel permeation chromatography profile is described. “2” indicates that there are two or more peaks in the distribution of the polymer, indicating that it has a partially crosslinked structure.

  Next, except that the addition amount of the bifunctional crosslinking agent during polymerization was changed to the amount shown in Table 8 below, the structure [(P-53) to (P -57)] is exemplified together with its weight average molecular weight and dispersity, and the bifunctional cross-linking agent added during polymerization and its addition amount.

  The specific single alkali-soluble polymer according to the present invention may be used alone or in combination of two or more. Further, the polymer of the present invention may be used alone or in combination with each other, such as a crosslinked structure-containing alkali-soluble polymer, or may be used in combination with one or more other binder polymers not having a partially crosslinked structure. It may be used. The other binder polymer used in combination is used in the range of 1 to 60% by mass, preferably 1 to 40% by mass, and more preferably 1 to 20% by mass with respect to the total mass of the binder polymer component. As other binder polymers that can be used in combination, conventionally known ones can be used without limitation, and specifically, acrylic main chain binders, urethane binders, and the like that are often used as film-forming polymers for polymerizable compositions are preferably used. .

  The partially crosslinked encapsulated alkali-soluble polymer of the present invention has excellent stability and can exhibit excellent film properties because it has a gelled structure.

[Polymerizable composition]
Next, the polymerizable composition of the present invention will be described.
The polymerizable composition of the present invention is characterized by containing (A) an alkali-soluble polymer having an intramolecular cross-linked structure, and further contains (B) a polymerizable compound and (C) a polymerization initiator. It is preferable to do.

The total content of the (A) crosslinked structure-encapsulating alkali-soluble polymer and the other polymer used in combination in the polymerizable composition of the present invention can be determined as appropriate, but is usually based on the total mass of the nonvolatile components. It is 10-90 mass%, Preferably it is 20-80 mass%, More preferably, it is the range of 30-70 mass%. For example, when this polymerizable composition is used for the recording layer of an image recording material (lithographic printing plate precursor), the same addition amount may be used.
The polymerizable composition of the present invention is suitably used as a recording layer for a lithographic printing plate precursor. A lithographic printing plate precursor to which such a polymerizable composition is applied can be directly recorded from digital data such as a computer by exposure using a laser beam or the like. Hereinafter, each component which may be contained in the polymerizable composition of the present invention will be described sequentially.
[(B) Polymerizable compound]
As the polymerizable compound (B) used in the polymerizable composition of the present invention, a conventionally known polymerizable compound described below, that is, a compound having an ethylenically unsaturated bond capable of addition polymerization can be used.
Examples of conventionally known addition-polymerizable compounds having an ethylenically unsaturated bond include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and aliphatic polyvalent acids. Examples thereof include esters with polyhydric alcohol compounds, amides of the above unsaturated carboxylic acids and aliphatic polyvalent amine compounds, and the like.

Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include the following:
Acrylic esters include ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylol Methylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetra Acrylate, 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- (acryloxyethoxy) phenyl] dimethylmethane. 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. Furthermore, the mixture of the above-mentioned ester monomer can also be mention | raise | lifted. Specific examples of an amide monomer of an aliphatic polyvalent amine compound and an unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexa. Examples include methylene bis-methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, and xylylene bismethacrylamide.

Other examples include vinyls containing a hydroxyl group represented by the following general formula (A) in a polyisocyanate compound having two or more isocyanate groups per molecule described in JP-B-48-41708. Examples thereof include a vinylurethane compound containing two or more polymerizable vinyl groups in one molecule to which a monomer is added.
_{CH 2 = C (R) COOCH} 2 CH (R ') OH (A)
(However, R and R ′ represent H or CH _3. )

  Further, urethane acrylates as described in JP-A-51-37193, JP-A-48-64183, JP-B-49-43191, JP-B-52-30490 are disclosed. Polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid can be used. Furthermore, Journal of Japan Adhesion Association vol.20, No. 7, pages 300 to 308 (1984) as photocurable monomers and oligomers can also be used. In the present invention, these monomers can be used in a chemical form such as a prepolymer, that is, a dimer, a trimer and an oligomer, or a mixture thereof and a copolymer thereof.

  The polymerizable group used is preferably 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, and the unsaturated carboxylic acid and aliphatic Esters with polyhydric alcohol compounds are most preferred from the viewpoints of developability and printing durability when applied to the recording layer of a lithographic printing plate precursor.

  The amount of the polymerizable compound used is preferably 5% to 90% with respect to the mass of the total solid content of the polymerizable composition, from the viewpoints of film formation, printing durability, and storage stability. More preferably, it is 10% -80%, More preferably, it is 20% -75%.

[(C) Polymerization initiator]
Preferred (C) polymerization initiators used in the polymerizable composition of the present invention include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, and (d) thio compounds. (E) hexaarylbiimidazole compound, (f) ketoxime ester compound, (g) borate compound, (h) azinium compound, (i) metallocene compound, (j) active ester compound, (k) carbon halogen bond And the like. Specific examples of the above (a) to (k) are given below, but the present invention is not limited to these.

(A) Aromatic ketones (a) Aromatic ketones preferred as the polymerization initiator used in the present invention include "RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY" P. Fouassier, J. et al. F. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in Rabek (1993), p77-117. For example, the following compounds are mentioned.

Among them, particularly preferred examples of (a) aromatic ketones include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, such as the following compounds: Is mentioned.

  Examples of the α-substituted benzoin compounds described in JP-B-47-22326 include the following compounds.

  Examples thereof include benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, for example, the following compounds.

  Examples of the benzoin ethers described in JP-B-60-26403 and JP-A-62-181345 include the following compounds.

  Examples of the α-aminobenzophenones described in JP-B-1-34242, US Pat. No. 4,318,791, and European Patent 0284561A1, such as the following compounds.

  P-Di (dimethylaminobenzoyl) benzene described in JP-A-2-211452, for example, the following compounds may be mentioned.

  Examples of the thio-substituted aromatic ketone described in JP-A-61-194062 include the following compounds.

  The acylphosphine sulfide described in JP-B-2-9597, for example, the following compounds may be mentioned.

  Examples of the acylphosphine described in JP-B-2-9596 include the following compounds.

  Further, thioxanthones described in JP-B-63-61950, coumarins described in JP-B-59-42864, and the like can also be mentioned.

(B) Onium Salt Compound As the polymerization initiator (b) preferable as the polymerization initiator used in the present invention, compounds represented by the following general formulas (1) to (3) may be mentioned.

In general formula (1), Ar ¹ and Ar ² each independently represent an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred substituents when this aryl group has a substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a carbon atom having 12 or less carbon atoms. An aryloxy group is mentioned. (Z ² ) ⁻ represents a counter ion selected from the group consisting of halogen ion, perchlorate ion, carboxylate ion, tetrafluoroborate ion, hexafluorophosphate ion, and sulfonate ion, preferably perchloric acid Ions, hexafluorophosphate ions, and aryl sulfonate ions.

In General Formula (2), Ar ³ represents an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and 12 or less carbon atoms. Examples thereof include an alkylamino group, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, or a diarylamino group having 12 or less carbon atoms. (Z ³ ) ⁻ represents a counter ion having the same meaning as (Z ² ) ⁻ .

In general formula (3), R ²³ , R ²⁴ and R ²⁵ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferable substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or an aryloxy group having 12 or less carbon atoms. (Z ⁴ ) ⁻ represents a counter ion having the same meaning as (Z ² ) ⁻ .

  Specific examples of onium salts that can be suitably used in the present invention include paragraph numbers [0030] to [0033] of JP-A No. 2001-133969 and paragraph numbers [0096] to [0101 of JP-A No. 2001-92127. And those described in paragraph numbers [0015] to [0046] of JP-A-2001-343742.

  The onium salt used in the present invention preferably has a maximum absorption wavelength of 400 nm or less, and more preferably 360 nm or less. By making the absorption wavelength in the ultraviolet region in this way, the lithographic printing plate precursor can be handled under white light.

(C) Organic peroxide Preferred as the polymerization initiator used in the present invention (c) Organic peroxide includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples include methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (tertiarybutylperoxy) -3,3,5. -Trimethylcyclohexane, 1,1-bis (tertiarybutylperoxy) cyclohexane, 2,2-bis (tertiarybutylperoxy) butane, tertiarybutylhydroperoxide, cumene hydroperoxide, diisopropylbenzenehydride Loperoxide, parameter hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, ditertiary butyl peroxide, tertiary butyl Cumyl peroxide, dicumyl peroxide, bis (tertiarybutylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (tertiarybutylperoxy) hexane, 2,5-xanoyl peroxide, peroxy Succinic oxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, meta-toluoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate Nate, dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, tertiary butyl peroxyacetate, tertiary butyl peroxypivalate, tertiary butyl peroxyneodecanoate, tarsha Tributyl peroxyoctanoate, tertiary butyl peroxy-3,5,5-trimethylhexanoate, tertiary butyl peroxylaurate, tertiary carbonate, 3,3'4,4'-tetra- (t -Butylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-hexylperoxycarbonyl) benzophenone, 3, 3'4, 4 -Tetra- (t-octylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (cumylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (p-isopropylcumylperoxy) Carbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogen diphthalate), carbonyldi (t-hexylperoxydihydrogen diphthalate), and the like.

  Among them, 3,3'4,4'-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3'4 4'-tetra- (t-hexylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-octylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (cumylper) Peroxyesters such as (oxycarbonyl) benzophenone, 3,3'4,4'-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, di-t-butyldiperoxyisophthalate are preferred.

(D) Thio compound As a preferable (d) thio compound as a polymerization initiator used by this invention, the compound which has a structure shown by following General formula (4) is mentioned.

In the general formula (4), R ²⁶ represents an alkyl group, an aryl group or a substituted aryl group, and R ²⁷ represents a hydrogen atom or an alkyl group. R ²⁶ and R ²⁷ represent a group of nonmetallic atoms necessary to form a 5-membered to 7-membered ring which may be bonded to each other and contain a hetero atom selected from oxygen, sulfur and nitrogen atoms.
As an alkyl group in the said General formula (4), a C1-C4 thing is preferable. The aryl group is preferably one having 6 to 10 carbon atoms such as a phenyl group or a naphthyl group, and the substituted aryl group includes a halogen atom such as a chlorine atom, a methyl group as described above. And those substituted with an alkoxy group such as methoxy group and ethoxy group. R ²⁷ is preferably an alkyl group having 1 to 4 carbon atoms. Specific examples of the thio compound represented by the general formula (4) include the following compounds.

(E) Hexaarylbiimidazole compounds (e) Hexaarylbiimidazole compounds preferred as the polymerization initiator used in the present invention include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2 , 2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4', 5,5'-tetra Phenylbiimidazole, 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'-tetrapheny Biimidazole, 2,2'-bis (o-nitrophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4', 5 , 5'-tetraphenylbiimidazole, 2,2'-bis (o-trifluorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole and the like.

(F) Ketooxime ester compound (f) The ketoxime ester compound preferable as a polymerization initiator used in the present invention includes 3-benzoyloxyiminobutan-2-one, 3-acetoxyiminobutane-2-one, 3 -Propionyloxyiminobutan-2-one, 2-acetoxyiminopentan-3-one, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, Examples include 3-p-toluenesulfonyloxyiminobutan-2-one and 2-ethoxycarbonyloxyimino-1-phenylpropan-1-one.

(G) Borate Compound As an example of the (g) borate compound preferable as the polymerization initiator used in the present invention, a compound represented by the following general formula (5) can be given.

In the general formula (5), R ²⁸ , R ²⁹ , R ³⁰ and R ³¹ 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 ²⁸ , R ²⁹ , R ³⁰ and R ³¹ are bonded to form a cyclic structure. May be. However, at least one of R ²⁸ , R ²⁹ , R ³⁰ and R ³¹ is a substituted or unsubstituted alkyl group. (Z ⁵ ) ⁺ represents an alkali metal cation or a quaternary ammonium cation.
Examples of the alkyl group for R ^{28 to} R ³¹ 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. The substituted alkyl group includes an alkyl group as described above, a halogen atom (for example, —Cl, —Br, etc.), a cyano group, a nitro group, an aryl group (preferably a phenyl group), a hydroxy group, —COOR ³² (here R ³² represents a hydrogen atom, an alkyl group having 1 to 14 carbon atoms, or an aryl group), —OCOR ³³ or —OR ³⁴ (where R ³³ and R ³⁴ are alkyl groups having 1 to 14 carbon atoms, or aryl. And a group having a substituent represented by the following formula.

Here, R ³⁵ and R ³⁶ independently represent a hydrogen atom, an alkyl group having 1 to 14 carbon atoms, or an aryl group.
The aryl group of R ^{28 to} R ³¹ includes 1 to 3 ring aryl groups such as a phenyl group and a naphthyl group, and the substituted aryl group is a substitution of the above substituted alkyl group with the above aryl group. Those having a group or an alkyl group having 1 to 14 carbon atoms are included. Examples of the alkenyl group for R ^{28 to} R ³¹ include linear, branched and cyclic groups having 2 to 18 carbon atoms. Examples of the substituent of the substituted alkenyl group include those listed as the substituents of the substituted alkyl group. Examples of the alkynyl group of R ^{28 to} R ³¹ include straight chain 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 ^{28 to} R ³¹ include a 5-membered ring or more, preferably a 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 (5) are described in US Pat. Nos. 3,567,453 and 4,343,891, European Patents 109,772 and 109,773. Compounds and those shown below are mentioned.

(H) Azinium Compound Preferred examples of the azinium salt compound used as the polymerization initiator used in the present invention include JP-A Nos. 63-138345, 63-142345, and 63-142346. And compounds having an N—O bond described in JP-A-63-143537 and JP-B-46-42363.

(I) Metallocene compound (i) Metallocene compound preferred as a polymerization initiator used in the present invention is disclosed in JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, Examples thereof include titanocene compounds described in JP-A-2-249 and JP-A-2-4705, and iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109.

  Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3. 4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti- Bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti- -2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyridin-1-yl) phenyl) titanium bis (cyclopentadienyl) bis [2,6-difluoro-3- (methylsulfonamido) phenyl] titanium, bis (cyclopentadi Enyl) bis [2,6-difluoro-3- (N-butylbialoyl-amino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butyl- (4-chlorobenzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3 -(N-benzyl-2,2-dimethylpentanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (2-ethylhexyl) -4-tolyl-sulfonyl] ) Amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-oxaheptyl) benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2 , 6-Difluoro-3- (N- (3,6-dioxadecyl) benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bi [2,6-difluoro-3- (trifluoromethylsulfonyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (trifluoroacetyl) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (2-chlorobenzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (4-chloro Benzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3,6-dioxadecyl) -2,2-dimethylpentanoylamino) phenyl] titanium, bis (Cyclopentadienyl) bis [2,6-difluoro-3- (N- (3,7-dimethyl-7-methoxyoctyl) benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6 -Difluoro-3- (N-cyclohexylbenzoylamino) phenyl] titanium and the like.

(J) Active ester compound Preferred as the polymerization initiator used in the present invention (j) is an imide sulfonate compound described in JP-B-62-2223, JP-B-63-14340, JP-A-59. And active sulfonates described in JP-A-174831.

(K) Compound having carbon halogen bond Preferred compounds (k) having a carbon halogen bond as the polymerization initiator used in the present invention include compounds represented by the following general formulas (6) to (12). be able to.

In the general formula (6), X ² represents a halogen atom, and Y ¹ represents —C (X ² ) ₃ , —NH ₂ , —NHR ³⁸ , —NR ³⁸ , —OR ³⁸ . Here, R ³⁸ represents an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. R ³⁷ represents —C (X ² ) ₃ , an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or a substituted alkenyl group.

In the general formula (7), R ³⁹ is an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group, a substituted aryl group, a halogen atom, an alkoxy group, a substituted alkoxyl group, a nitro group or a cyano group, X ³ is a halogen atom, and n is an integer of 1 to 3.

In the general formula (8), R ⁴⁰ is an aryl group or a substituted aryl group, R ⁴¹ is a group or halogen shown below, and Z ⁶ is —C (═O) — or —C (═S). - or -SO ₂ - is.

(R ⁴² and R ⁴³ are an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group or a substituted aryl group, R ⁴⁴ is the same as R ³⁸ in the general formula (6), and X ³ is A halogen atom, and m is 1 or 2.)

In the general formula (9), R ⁴⁵ is an optionally substituted aryl group or heterocyclic group, R ⁴⁶ is a trihaloalkyl group or trihaloalkenyl group having 1 to 3 carbon atoms, and p is 1 2 or 3.

In general formula (10), it is a carbonylmethylene heterocyclic compound having a trihalogenomethyl group, wherein L ⁷ is a hydrogen atom or of the formula: CO— (R ⁴⁷ ) q (C (X ⁴ ) ₃ ) r. Q ² is a sulfur, selenium or oxygen atom, dialkylmethylene group, alkene-1,2-ylene group, 1,2-phenylene group or N—R group, and M ⁴ is a substituted or unsubstituted group. An alkylene group or an alkenylene group, or a 1,2-arylene group, R ⁴⁸ is an alkyl group, an aralkyl group or an alkoxyalkyl group, and R ⁴⁷ is a carbocyclic or heterocyclic divalent aromatic group. X ⁴ is a chlorine, bromine or iodine atom and q = 0 and r = 1 or q = 1 and r = 1 or 2. ).

General formula (11) is a 4-halogeno-5- (halogenomethyl-phenyl) -oxazole derivative, wherein X ⁵ is a halogen atom, t is an integer of 1 to 3, and s is 1 to 1 4 of an integer, R ⁴⁹ is a hydrogen atom or a CH _3-t X ⁵ _t group, R ⁵⁰ represents an s-valent optionally substituted unsaturated organic group.

General formula (12) is a 2- (halogenomethyl-phenyl) -4-halogeno-oxazole derivative, wherein X ⁶ is a halogen atom, v is an integer of 1 to 3, and u is 1 to 1 4 of an integer, R ⁵¹ is a hydrogen atom or a CH _3-v X ⁶ _v group, R ⁵² represents an unsaturated organic group which may be substituted for u-valent.

  Specific examples of such a compound having a carbon-halogen bond include those 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 British Patent 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, etc. And compounds described in JP-A-53-133428, such as 2- (4-methoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxy-naphtho). -1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- [4- (2-ethoxyethyl) -naphth-1-yl] -4,6-bis-to Chloromethyl-S-triazine, 2- (4,7-dimethoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine), 2- (acenaphtho-5-yl) -4,6- Examples include compounds described in German Patent No. 3333724, such as bis-trichloromethyl-S-triazine, and the like.

  F.F. C. J. Schaefer et al. Org. Chem. 29, 1527 (1964), such as 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-6-trichloromethyl-S-triazine, etc. Can do. Furthermore, for example, the following compounds described in JP-A-62-258241 can be exemplified.

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

  Alternatively, M. P. Hutt, E .; F. Elslager and L. M.M. The following compounds that can be easily synthesized by those skilled in the art according to the synthesis method described in “Journalof Heterocyclic Chemistry”, Volume 7 (No. 3) by Herbel, page 511 et seq. (1970) Examples of the group include the following compounds.

In addition, specific aromatic sulfonium salts described in JP 2001-92127 A, Japanese Patent Application 2000-266797, Japanese Patent Application 2001-177150, Japanese Patent Application 2000-184603, and the like previously proposed by the applicant of the present application are also included. It can be mentioned as a preferred polymerization initiator.
The most preferred examples of the polymerization initiator used in the polymerizable composition of the present invention include titanocene compounds, aromatic sulfonium salts, and trihalomethyl-S-triazine compounds.
In the present invention, (C) the polymerization initiator may be used alone or in combination of two or more.
The (C) polymerization initiator in the polymerizable composition of the present invention is preferably added in an amount of 0.01 to 10% by mass, more preferably 0.1 to 2% by mass in the total solid content. Moreover, when using this for the recording layer of a lithographic printing plate precursor, the preferable content is the same as described above.

[(D) Sensitizing dye]
A sensitizing dye is preferably added to the polymerizable composition of the present invention from the viewpoint of improving sensitivity. Examples of the sensitizing dye include a spectral sensitizing dye and a dye or pigment that absorbs light from a light source and interacts with a polymerization initiator.

<Spectral sensitizing dye or dye>
Spectral sensitizing dyes or dyes preferred as sensitizing dyes used in the present invention are polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal). ), Cyanines (eg thiacarbocyanine, oxacarbocyanine), merocyanines (eg merocyanine, carbomerocyanine), thiazines (eg thionine, methylene blue, toluidine blue), acridines (eg acridine orange, chloroflavin) , Acriflavine), phthalocyanines (eg, phthalocyanine, metal phthalocyanine), porphyrins (eg, tetraphenylporphyrin, central metal-substituted porphyrin), chlorophylls (eg, chlorophyll) Chlorophyllin, center metal-substituted chlorophyll), metal complexes (for example, the following compound), anthraquinones (e.g., anthraquinone), squaryliums (e.g., squarylium), and the like.

The example of a more preferable spectral sensitizing dye or dye is illustrated below.
A styryl dye described in JP-B-37-13034. Preferable specific examples include the following compounds.

  Cationic dyes described in JP-A-62-143044. Preferable specific examples include the following compounds.

  Quinoxalinium salts described in JP-B-59-24147. Preferable specific examples include the following compounds.

  New methylene blue compounds described in JP-A 64-33104. Preferable specific examples include the following compounds.

  Anthraquinones described in JP-A No. 64-56767. Preferable specific examples include the following compounds.

  Benzoxanthene dyes described in JP-A-2-17714, acridines described in JP-A-2-226148 and JP-A-2-226149. Preferable specific examples include the following compounds.

  The pyrylium salts described in Japanese Patent Publication No. 40-28499. Preferable specific examples include the following compounds.

  Cyanines described in JP-B-46-42363. Preferable specific examples include the following compounds.

  A benzofuran dye described in JP-A-2-63053. Preferable specific examples include the following compounds.

  Conjugated ketone dyes described in JP-A-2-85858 and JP-A-2-216154. Preferable specific examples include the following compounds.

  A dye described in JP-A No. 57-10605 and an azocinnamylidene derivative described in JP-B-2-30321. Preferable specific examples include the following compounds.

  Cyanine dyes described in JP-A-1-287105. Preferable specific examples include the following compounds.

  Xanthene dyes described in JP-A-62-31844, JP-A-62-31848, and JP-A-62-143043. Preferable specific examples include the following compounds.

  Aminostyryl ketone described in JP-B-59-28325. Preferable specific examples include the following compounds.

A dye represented by the following general formulas (13) to (15) described in JP-A-2-179634.

In general formulas (13) to (15), A ³ represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, an alkyl or aryl-substituted nitrogen atom or a dialkyl-substituted carbon atom, and Y ² represents hydrogen Represents an atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group, an acyl group, or a substituted alkoxycarbonyl group, R ⁵³ and R ⁵⁴ are a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or as a _{^{substituent, -OR 55, - (CH 2}} CH 2 O) w -R 55, halogen atom (F, Cl, Br, I ), and substitution of 1 to 18 carbon atoms and having a group represented by the following formula An alkyl group (wherein R ⁵⁵ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, B ¹ represents a dialkylamino group, a hydroxyl group, an acyloxy group, a halogen atom or a nitro group. W is an integer of 0 to 4) The It is.

A merocyanine dye represented by the following general formula (16) described in JP-A-2-244050.

In the general formula (16), R ⁵⁶ and R ⁵⁷ each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxycarbonyl group, an aryl group, a substituted aryl group or an aralkyl group. A ⁴ represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, an alkyl or aryl-substituted nitrogen atom, or a dialkyl-substituted carbon atom. X ⁷ represents a nonmetallic atom group necessary for forming a nitrogen-containing hetero five-membered ring. Y ³ represents a substituted phenyl group, an unsubstituted or substituted polynuclear aromatic ring, or an unsubstituted or substituted heteroaromatic ring. Z ⁷ represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group, an alkoxy group, an alkylthio group, an arylthio group, a substituted amino group, and an acyl group, or an alkoxycarbonyl group, and Y ³ They may be bonded to each other to form a ring. Preferable specific examples include the following compounds.

  A merocyanine dye represented by the following general formula (17) described in JP-B-59-28326.

In the general formula (17), R ⁵⁸ and R ⁵⁹ each represent a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or an aralkyl group, and they may be the same or different from each other. X ⁸ represents a substituent having a Hammett's sigma (σ) value in the range of −0.9 to +0.5.

  A merocyanine dye represented by the following general formula (18) described in JP-A-59-89303.

In general formula (18), R ⁶⁰ and R ⁶¹ each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group or an aralkyl group. X ⁹ represents a substituent having a Hammett sigma (σ) value in the range of −0.9 to +0.5. Y ⁴ represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group, an acyl group or an alkoxycarbonyl group. Preferable specific examples include the compounds shown below.

A merocyanine dye represented by the following general formula (19) described in Japanese Patent Application No. 6-269047.

In the general formula (19), R ⁶² , R ⁶³ , R ⁶⁴ , R ⁶⁵ , R ⁷⁰ , R ⁷¹ , R ⁷² and R ⁷³ are each independently a hydrogen atom, a halogen atom, an alkyl group, a substituted alkyl group, Aryl group, substituted aryl group, hydroxyl group, substituted oxy group, mercapto group, substituted thio group, amino group, substituted amino group, substituted carbonyl group, sulfo group, sulfonate group, substituted sulfinyl group, substituted sulfonyl group, phosphono group, substituted Represents a phosphono group, a phosphonate group, a substituted phosphonate group, a cyano group, a nitro group, or R ⁶² and R ⁶³ , R ⁶³ and R ⁶⁴ , R ⁶⁴ and R ⁶⁵ , R ⁷⁰ and R ⁷¹ , R ⁷¹ and R ⁷² may be bonded R ⁷² and R ⁷³ with each other to form an aliphatic or aromatic ring, R ⁶⁶ represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group, R ⁶⁷ Is a substitution, or Substituted alkenyl group, or a substituted or unsubstituted alkynyl group, R ^68, R ⁶⁹ are each independently a hydrogen atom, a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a substituted Represents a carbonyl group. Preferable specific examples include the compounds shown below.

  A benzopyran dye represented by the following general formula (20) described in Japanese Patent Application No. 7-164583.

In the general formula (20), R ^{74 to} R ⁷⁷ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a hydroxyl group, an alkoxy group or an amino group. R ^{74 to} R ⁷⁷ may form a ring composed of a nonmetallic atom together with carbon atoms to which they can be bonded. R ⁷⁸ represents a hydrogen atom, an alkyl group, an aryl group, a heteroaromatic group, a cyano group, an alkoxy group, a carboxy group, or an alkenyl group. R ⁷⁹ is a group represented by R ⁷⁸ or —Z ⁷ —R ⁷⁸ , and Z ⁷ represents a carbonyl group, a sulfonyl group, a sulfinyl group or an arylene carbonyl group. R ⁷⁸ and R ⁷⁹ may both form a ring composed of a nonmetallic atom. A ⁵ represents an O atom, an S atom, NH or an N atom having a substituent. B ² represents an O atom or a group of ═C (G ⁷ ) (G ⁸ ). G ⁷ and G ⁸ may be the same or different, and may be a hydrogen atom, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, an arylcarbonyl group, an alkylthio group, an arylthio group, an alkylsulfonyl group, an arylsulfonyl group, Or represents a fluorosulfonyl group. However, G ⁷ and G ⁸ are not hydrogen atoms at the same time. G ⁷ and G ⁸ may form a ring composed of a nonmetallic atom together with a carbon atom.

  In addition, specific indolenine cyanine dyes described in the specifications of Japanese Patent Application Nos. 2001-6326 and 2001-237840 previously proposed by the present inventors are also preferable examples.

  In addition, the following infrared absorbers (dyes or pigments) are also preferably used as sensitizing dyes. Preferred examples of the dye include cyanine described in, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787. And dyes, cyanine dyes described in British Patent 434,875, and the specific indolenine cyanine dyes.

  Further, near infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used, and further substituted aryl benzoates described in US Pat. No. 3,881,924 are also used. (Thio) pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A 58-181051, 58-220143, 59 -41363, 59-84248, 59-84249, 59-146063, 59-146061, pyranyl compounds described in JP-A-59-216146, cyanine dyes described in US The pentamethine thiopyrylium salt described in Japanese Patent No. 4,283,475, and the like described in Japanese Patent Publication Nos. 5-13514 and 5-19702 That pyrylium compounds are also preferably used.

  In addition, near infrared absorbing dyes described as formulas (I) and (II) in US Pat. No. 4,756,993 and phthalocyanine dyes described in EP 916513A2 are also preferable dyes. Can do.

  Furthermore, the anionic infrared absorber described in Japanese Patent Application No. 10-79912 can also be suitably used. An anionic infrared absorbing agent refers to an anionic infrared absorbing agent having an anionic structure without a cationic structure in the mother nucleus of a dye that substantially absorbs infrared rays. Examples include (c1) anionic metal complexes, (c2) anionic carbon black, (c3) anionic phthalocyanine, and (c4) a compound represented by the following general formula (21). The counter cation of these anionic infrared absorbers is a monovalent cation containing a proton or a polyvalent cation.

  Here, the (c1) anionic metal complex refers to an anion that forms an anion in the central metal and the entire ligand of the complex part that substantially absorbs light.

  Examples of (c2) anionic carbon black include carbon black to which anionic groups such as sulfonic acid, carboxylic acid, and phosphonic acid groups are bonded as substituents. In order to introduce these groups into carbon black, as described in Carbon Black Handbook 3rd Edition (Edited by Carbon Black Association, April 5, 1995, published by Carbon Black Association), page 12, What is necessary is just to take means, such as oxidizing carbon black.

  (C3) Anionic phthalocyanine refers to a phthalocyanine skeleton bonded with the anionic group previously mentioned in the description of (c2) as a substituent to form an anion as a whole.

Next, the compound (c4) represented by the general formula (21) will be described in detail. In the general formula (21), G ⁹ represents an anionic substituent, and G ¹⁰ represents a neutral substituent. (X ¹⁰ ) ⁺ represents a 1 to m-valent cation containing a proton, and m represents an integer of 1 to 6. M ⁵ represents a conjugated chain, and this conjugated chain M ⁵ may have a substituent or a ring structure. The conjugated chain M ⁵ can be represented by the following formula.

In the formula, R ⁸⁰ , R ⁸¹ and R ⁸² are each independently a hydrogen atom, halogen atom, cyano group, alkyl group, aryl group, alkenyl group, alkynyl group, carbonyl group, thio group, sulfonyl group, sulfinyl group, oxy A group and an amino group, which may be linked to each other to form a ring structure. n represents an integer of 1 to 8.

  Of the anionic infrared absorbers represented by the general formula (21), those of the following IRA-1 to IRA-5 are preferably used.

  Moreover, the cationic infrared absorber shown to the following IRC-1-IRC-44 can also be used preferably.

In the structural formula, T ⁻ represents a monovalent counter anion, preferably a halogen anion (F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ ), a Lewis acid anion (BF ₄ ⁻ , PF ₆ ⁻ , SbCl _6). ⁻ , ClO ₄ ⁻ ), an alkyl sulfonate anion, and an aryl sulfonate anion.

  The alkyl of the alkyl sulfonic acid means a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, a butyl group. , Pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s-butyl, t- A butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group, and 2-norbornyl group can be exemplified. Of these, linear alkyl groups having 1 to 12 carbon atoms, branched alkyl groups having 3 to 12 carbon atoms, and cyclic alkyl groups having 5 to 10 carbon atoms are more preferable.

  The aryl of the aryl sulfonic acid includes one consisting of one benzene ring, two or three benzene rings forming a condensed ring, and one having a benzene ring and a 5-membered unsaturated ring forming a condensed ring. Specific examples thereof include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenabutenyl group, and a fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable.

  Moreover, the nonionic infrared absorber shown to the following IRN-1-IRN-9 can also be used preferably.

  Among the exemplified compounds, IRA-1 is a particularly preferable anionic infrared absorber, and IRC-7, IRC-30, IRC-40, and IRC-42 are nonionic infrared absorbers as cationic infrared absorbers. Examples of the agent include IRN-9. Other preferable cationic infrared absorbers include specific indolenine cyanine dyes described in Japanese Patent Application Nos. 2001-6326 and 2001-237840 previously filed by the present applicant. it can.

<Pigment>
Examples of the pigment used in the present invention include commercially available pigments and color index (CI) manual, “Latest Pigment Handbook” (edited by Japan Pigment Technology Association, published in 1977), “Latest Pigment Application Technology” (CMC Publishing, 1986), “Printing Ink Technology”, CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

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

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. When the particle diameter of the pigment is less than 0.01 μm, it is not preferable from the viewpoint of stability of the dispersion in the image recording layer coating solution, and when it exceeds 10 μm, it is not preferable from the viewpoint of uniformity of the image recording layer.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

The sensitizing dye added to accelerate the curing reaction of the polymerizable composition of the present invention may be added directly to the composition together with other components, but a separate layer adjacent to this may be provided. Even if it is added thereto, the same effect can be obtained.
In particular, when the polymerizable composition of the present invention is used for a negative recording layer of a lithographic printing plate precursor described later, it may be added to the same layer of the recording layer or may be added to another layer provided. However, when a negative lithographic printing plate precursor is produced, the optical density at the absorption maximum in the wavelength range of 300 nm to 1200 nm of the recording layer is preferably between 0.1 and 3.0. . In this range, recording with high sensitivity is possible. Since the optical density is determined by the addition amount of the sensitizing dye and the thickness of the recording layer, the predetermined optical density can be obtained by controlling both conditions.
The optical density of the recording layer can be measured by a conventional method. As a measuring method, for example, on a transparent or white support, a recording layer having a thickness appropriately determined in a range where the coating amount after drying is necessary as a lithographic printing plate is formed, and a transmission optical densitometer is used. Examples thereof include a measuring method, a method of forming a recording layer on a reflective support such as aluminum, and measuring a reflection density.
These pigments or dyes are 0.01 to 50% by weight, preferably 0.1 to 10% by weight, particularly preferably 0.5 to 10% by weight, based on the total solid content of the polymerizable composition. In the case of a pigment, it can be particularly preferably added at a ratio of 0.1 to 10% by mass. When the amount of the pigment or dye added is in this range, high sensitivity can be achieved, and a uniform and excellent film can be formed.

  When (D) sensitizing dye is used, the molar ratio of (C) polymerization initiator to (D) sensitizing dye in the polymerizable composition is 100: 0 to 1:99, more preferably 90: 10 to 10:90, most preferably 80:20 to 20:80.

Furthermore, the polymerizable composition of the present invention may contain a known compound having a function of further improving sensitivity or suppressing polymerization inhibition by oxygen as a co-sensitizer.
Examples of such co-sensitizers include amines such as MR Sander et al., “Journal of Polymer Society”, Vol. 10, page 3173 (1972), Japanese Examined Patent Publication No. 44-20189, JP-A No. 51-82102, Compounds described in JP-A-52-134692, JP-A-59-138205, JP-A-60-84305, JP-A-62-18537, JP-A-64-33104, Research Disclosure 33825, etc. Specific examples include triethanolamine, p-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline, and the like.

  Other examples of co-sensitizers include thiols and sulfides, for example, thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142773, and JP-A-56. And the like, and specific examples include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzoimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercaptonaphthalene. Etc.

  Other examples include amino acid compounds (eg, N-phenylglycine, N-phenyliminodiacetic acid and derivatives thereof), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), Hydrogen donors described in Japanese Patent Publication No. 55-34414, sulfur compounds described in Japanese Patent Application No. 5-91089 (eg, trithiane), phosphorus compounds described in Japanese Patent Application No. 5-32147 (diethylphosphite etc.), Examples thereof include Si-H and Ge-H compounds described in Japanese Patent Application No. 6-191605.

  When using the above-mentioned co-sensitizer, it is appropriate to use 0.01 to 50 parts by weight, more preferably 0.02 to 20 parts by weight, most preferably, relative to 1 part by weight of the polymerization initiator. 0.05 to 10 parts by mass.

[Other ingredients]
In addition to the components described above, various additives such as a laser light absorber, a colorant, a plasticizer, and a polymerization inhibitor may be added to the polymerizable composition of the present invention as necessary.

In order to prevent unnecessary thermal polymerization of a compound having a polymerizable ethylenically unsaturated double bond contained in the composition during the production or storage of the polymerizable composition of the present invention, a small amount of thermal polymerization is prevented. It is desirable to add an agent.
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-tert-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like.
The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the mass of the entire composition.
If necessary, higher fatty acid derivatives such as behenic acid and behenic acid amide may be added to prevent polymerization inhibition due to oxygen and unevenly distributed on the surface of the photosensitive layer during the drying process after coating. Good. 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.

  Further, a dye or pigment may be added for the purpose of coloring the recording layer. Thereby, when the polymerizable composition of the present invention is applied to a lithographic printing plate precursor, so-called plate inspection such as visibility after plate making and suitability for an image density measuring instrument can be improved. As the colorant used here, it is particularly preferable to use a pigment. This is because many dyes may cause a reduction in exposure sensitivity of the polymerizable composition, and this point should be taken into consideration when using the dye as a colorant. Specific examples of the colorant 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. Can be mentioned. 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.

  In addition to the above-mentioned additives, known additives such as inorganic fillers, plasticizers, and oil-sensitizing agents that can improve the ink inking property on the surface of the photosensitive layer in order to improve the physical properties of the cured film. May be added.

  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.

  In addition, additives such as UV initiators and thermal crosslinking agents are used to enhance the effect of post-development heating / exposure treatment for the purpose of improving the film strength (printing durability) of the lithographic printing plate precursor described later You can also

  The polymerizable composition of the present invention is an image recording material typified by a lithographic printing plate precursor described later, a highly sensitive optical modeling material, a change in refractive index accompanying polymerization, a hologram material, a photoresist, etc. It can also be applied to the production of electronic materials.

[Image recording material (lithographic printing plate precursor)]
The above-described polymerizable composition of the present invention is suitably used as a negative recording layer of an image recording material typified by a lithographic printing plate precursor. Hereinafter, the image recording material of the present invention will be described. The image recording material of the present invention is a suitable application example of the polymerizable composition of the present invention. The image recording material of the present invention is constituted by providing a recording layer containing the polymerizable composition of the present invention and, if necessary, other layers on a support.

(Recording layer)
The recording layer (photosensitive layer) in the image recording material of the present invention (hereinafter, appropriately referred to as a lithographic printing plate precursor) includes, as an essential component, the above-described (A) alkali-soluble polymer (crosslinked structure-containing polymer), (B) polymerization. A polymerizable photosensitive layer comprising a polymerizable composition (also referred to as an addition polymerizable compound) and a polymerizable composition containing (C) a polymerization initiator. Such a polymerizable photosensitive layer has a mechanism in which a polymerization initiator is decomposed by laser light to generate radicals, and the polymerizable compound causes a polymerization reaction by the generated radicals. Furthermore, the lithographic printing plate precursor according to the present invention is particularly suitable for plate making by direct drawing with a laser beam having a wavelength of 300 to 1,200 nm, and has higher printing durability and image than the conventional lithographic printing plate precursor. Expresses formability.

In the lithographic printing plate precursor according to the invention, in order to improve the adhesion between the recording layer and the support and to improve the development removability in the unexposed area of the recording layer, it is also possible to provide an intermediate layer therebetween. .
It is also possible to add a compound capable of forming an interaction with the support substrate in the recording layer. Examples of such a compound include a compound having a diazonium structure, a phosphone compound, and the like, which are added to the recording layer or added to the coating composition for forming the undercoat layer. And the printing durability can be improved. Further, in order to improve the removability of the non-image area, it is sufficient to add a hydrophilic polymer such as polyacrylic acid or polysulfonic acid, or to take a means such as forming an undercoat layer containing this, As a result, the developability of the non-image area is improved, and contamination of the non-image area can be effectively suppressed.

When the polymerizable composition of the present invention is applied on a support to form a recording layer, the polymerizable composition may be 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 is ethyl. These solvents can be used alone or in combination. The solid content in the coating solution is suitably 2 to 50% by mass.

The coating amount of the recording layer mainly affects the sensitivity of the recording layer, the developability, the strength of the exposed film, and the printing durability, and is preferably selected as appropriate according to the application. When the coating amount is too small, the printing durability tends to be lowered. When the coating amount is too large, the sensitivity is lowered, the exposure takes time, and the development process takes a longer time.
When the lithographic printing plate precursor according to the present invention is used as a lithographic printing plate precursor for scanning exposure, the recording layer coating amount is suitably in the range of about 0.1 to about 10 g / m ^{2 by} weight after drying. preferably from 0.5 to 5 g / m ^2.

(Support)
As a support that can be used in the lithographic printing plate precursor according to the present invention, a support having a hydrophilic surface is desirable, and any conventionally known hydrophilic support used in a lithographic printing plate can be used without any particular limitation. Can do.
The support substrate 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.), as described above For example, paper or plastic film laminated or vapor-deposited with a new metal is included. As the support, those obtained by subjecting the surface of these base materials to known physical and chemical treatments appropriate for the purpose of imparting hydrophilicity and improving the strength as required can be used.

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

  In the case of a support having a surface of metal, particularly aluminum, roughening (graining) treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluoride zirconate, phosphate, etc., or anodic oxidation treatment, etc. It is preferable that surface treatment is performed.

  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 solution of sodium silicate and has been hydrophilized can be used preferably. For example, as described in Japanese Patent Publication No. 47-5125, an aluminum plate was anodized. After that, an immersion treatment in an aqueous solution of an alkali metal silicate is preferably used. 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 thereof is used alone or in combination of two or more. 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 effective as such a hydrophilic treatment with a silicic acid compound on the surface of the support. Furthermore, a support body provided with electrolytic grains as disclosed in JP-B-46-27481, JP-A-52-58602, and JP-A-52-30503, the above-mentioned anodizing treatment and sodium silicate A surface treatment combining treatments 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.

  Further, after performing these treatments, a water-soluble resin such as polyvinyl phosphonic acid, a polymer and copolymer having a sulfonic acid group in the side chain, polyacrylic acid, a water-soluble metal salt (for example, zinc borate) or Those having a primer such as a yellow dye or an amine salt are also suitable.

As another example of the hydrophilic treatment on the surface of the support, a sol-gel treated substrate in which a functional group capable of causing an addition reaction by a radical as disclosed in Japanese Patent Application No. 5-304358 is also suitable. It is mentioned in.
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, a hydrophilic swelling layer described in JP-A-9-80744, and a special surface Examples thereof include sol-gel films made of titanium oxide, polyvinyl alcohol, and silicic acids described in JP-A-8-507727.

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

(Protective layer)
When the lithographic printing plate precursor according to the invention is used for a lithographic printing plate for scanning exposure, a protective layer can be provided on the recording layer as necessary. Such a lithographic printing plate precursor is usually exposed in the air, but the protective layer is a low molecular weight molecule such as oxygen or a basic substance present in the air that inhibits the image forming reaction caused by exposure in the photosensitive layer. Prevents the compound from being mixed into the photosensitive layer and enables exposure in the air. 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.

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

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

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

  On the other hand, various proposals have been made to improve the adhesion between these two layers. For example, in U.S. Patent Application No. 292,501 and U.S. Patent Application No. 44,563, an acrylic emulsion or a water-insoluble vinyl pyrrolidone-vinyl acetate copolymer is added to a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesion can be obtained by mixing ˜60 mass% and laminating on the polymerized layer. Any of these known techniques can be applied to the protective layer in the present invention. Such a coating method for the protective layer is described in detail in, for example, US Pat. No. 3,458,311 and JP-A-55-49729.

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

  Furthermore, other functions can be imparted to the protective layer. For example, when laser light is used as the light source, the photosensitive composition is excellent in photosensitivity at the wavelength of the light source, but may not be sensitized at other wavelengths. For example, if the light source is in the infrared region of 750 nm or more, it can be used in a bright room substantially, but in fact, it may be exposed to short-wave light such as light from a fluorescent lamp. In that case, it is preferable to add a colorant (such as a water-soluble dye) that is excellent in light transmittance of the light source and can efficiently absorb light having a wavelength of less than 700 nm. As another example, if the light source is in the ultraviolet region of 450 nm or less, it can be used under a safelight substantially. However, in actuality, there are cases where exposure is made with visible light of 500 nm or more. In that case, the addition of a colorant (such as a water-soluble dye) that excels in light transmittance of the light source and can efficiently absorb light of 500 nm or more can further enhance the suitability for safelight without causing a decrease in sensitivity. be able to.

As the exposure method for the lithographic printing plate precursor according to the invention, known methods can be used without limitation. A laser is preferable as the light source. For example, the following can be used as an available laser light source having a wavelength of 350 to 450 nm.
As a gas laser, Ar ion laser (364 nm, 351 nm, 10 mW to 1 W), Kr ion laser (356 nm, 351 nm, 10 mW to 1 W), He-Cd laser (441 nm, 325 nm, 1 mW to 100 mW), and Nd as a solid laser : Combination of YAG (YVO ₄ ) and SHG crystal × 2 times (355 mm, 5 mW to 1 W), combination of Cr: LiSAF and SHG crystal (430 nm, 10 mW). As the semiconductor laser system, KNbO ₃ , ring resonator (430 nm, 30 mW), waveguide type wavelength conversion element and AlGaAs, combination of InGaAs semiconductor (380 nm to 450 nm, 5 mW to 100 mW), waveguide type wavelength conversion element and AlGaInP, Combination of AlGaAs semiconductors (300 nm to 350 nm, 5 mW to 100 mW), AlGaInN (350 nm to 450 nm, 5 mW to 30 mW), other pulse lasers such as N ₂ laser (337 nm, pulse 0.1 to 10 mJ), XeF (351 nm, pulse 10 ~ 250 mJ).
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.

In addition, as an available light source of 450 nm to 700 nm, Ar ⁺ laser-(488 nm), YAG-SHG laser (532 nm), He-Ne laser (633 nm), He-Cd laser, red semiconductor laser (650-690 nm), Further, as an available light source of 700 nm to 1200 nm, a semiconductor laser (800 to 850 nm) and an Nd-YAG laser (1064 nm) can be preferably used.

Other ultra high pressure, high pressure, medium pressure, low pressure mercury lamp, chemical lamp, carbon arc lamp, xenon lamp, metal halide lamp, ultraviolet laser lamp (ArF excimer laser, KrF excimer laser, etc.), radiation as electron beam, X Lines, ion beams, far infrared rays, etc. can also be used.
Among the above, the light source used for image exposure of the image recording material according to the present invention is preferably a light source having a light emission wavelength from the near infrared region to the infrared region, and a solid laser or a semiconductor laser is particularly preferable.

  The exposure mechanism may be any of an internal drum system, an external drum system, a flat bed system, and the like. In addition, by using a highly water-soluble recording layer component according to the present invention, it can be made soluble in neutral water or weak alkaline water. After loading, the exposure-development processing is performed on the machine, and a so-called on-machine development method that does not require a special liquid bath development process can be performed.

  In the lithographic printing plate precursor according to the invention, usually, after image exposure, an unexposed portion of the recording layer is removed with a developer to obtain an image. Preferred developers used in the present invention include developers described in JP-B-57-7427, such as sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide. , Inorganic alkaline agents such as sodium triphosphate, dibasic sodium phosphate, tribasic ammonium phosphate, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, aqueous ammonia etc. and monoethanolamine or diethanolamine An aqueous solution of such an organic alkali agent is suitable. It is added so that the concentration of such an alkaline solution is 0.1 to 10% by mass, preferably 0.5 to 5% by mass.

Such an alkaline aqueous solution can contain a small amount of an organic solvent such as a surfactant, benzyl alcohol, 2-phenoxyethanol, or 2-butoxyethanol as necessary. Examples thereof include those described in US Pat. Nos. 3,375,171 and 3,615,480.
Furthermore, the developers described in JP-A-50-26601, 58-54341, JP-B-56-39464, and 56-42860 are also excellent.
In addition, the use of a specific aromatic nonionic surfactant-containing developer described in the specification of Japanese Patent Application No. 2001-62270 as a developer can be used for developing the system using a polymer-based polymerizable composition. It is more preferable in terms of sex.

The printing plate developed using the developer and the replenisher is post-treated with water-washing water, a rinsing solution containing a surfactant and the like, a desensitizing solution containing gum arabic and starch derivatives. As the post-treatment when the image recording material of the present invention is used as a printing plate, these treatments can be used in various combinations.
In addition, as the plate making process of the lithographic printing plate precursor according to the present invention, the entire surface may be heated before exposure, during exposure, and between exposure and development, if necessary. Such heating promotes an image forming reaction in the recording layer, and may have advantages such as improvement of sensitivity and printing durability and stabilization of sensitivity. Further, for the purpose of improving the image strength and printing durability, it is also effective to carry out whole surface post-heating or whole surface exposure on the developed image. Usually, heating before development is preferably performed under mild conditions of 150 ° C. or less. If the temperature is too high, problems such as covering the non-image area occur. Very strong conditions are used for heating after development. Usually, it is the range of 200-500 degreeC. In this temperature range, a sufficient image strengthening effect is exhibited, and problems such as deterioration of the support and thermal decomposition of the image portion do not occur. As a method for exposing a scanning exposure lithographic printing plate according to the present invention, a known method can be used without limitation.

  The image recording material of the present invention is particularly suitable for the recording layer of the lithographic printing plate precursor for scanning exposure described in detail, but is also suitable for other uses, for example, a high-sensitivity stereolithography material, and is accompanied by polymerization. It can also be applied to hologram materials using the change in refractive index and to the manufacture of electronic materials such as photoresists.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

[Synthesis of crosslinked polymer-containing alkali-soluble polymer]
(Synthesis Example 1: Alkali-soluble polymer (P-1))
In the flask, 2-bromo-2-methylpropionyloxyethyl methacrylate (0.5 mol), methyl methacrylate (0.295 mol), methacrylic acid (0.2 mol), compound I-1 (bifunctional crosslinking agent) (0. 005 mol), V-601 (manufactured by Wako Pure Chemical Industries, Ltd., azo thermal polymerization initiator) (0.006 mol) and N, N-dimethylacetamide (700 mL) are mixed and stirred at 80 ° C. for 5 hours. The reaction solution was cooled to 0 ° C., DBU (1,8-diazabicyclo [5,4,0] -7-undecene) (1.0 mol) was added, and the mixture was stirred for 5 hours, and then stirred in 10 L of 0.1N aqueous hydrochloric acid. While adding the reaction solution little by little, white powder precipitates. This powder was filtered and dried to obtain polymer P-1 in a yield of 85%. The structure of this material was confirmed by NMR, IR and GPC.
This synthesis example is a synthesis example in which a modification treatment with an acid is performed after the polymerization step.

<Synthesis Example 2: Alkali-soluble polymer P-28>
2-Bromo-2-methylpropionyloxyethyl methacrylate (0.5 mol), N-phenylmethacrylamide (0.395 mol), methacrylic acid (0.1 mol), compound I-33 (bifunctional cross-linking agent) in the flask (0.005 mol), V-601 (manufactured by Wako Pure Chemical Industries, Ltd., azo thermal polymerization initiator) (0.006 mol) and N, N-dimethylacetamide (700 mL) are mixed and stirred at 80 ° C. for 5 hours. The reaction solution was cooled to 0 ° C., DBU (1,8-diazabicyclo [5,4,0] -7-undecene) (1.0 mol) was added, and the mixture was stirred for 5 hours, and then stirred in 10 L of 0.1N aqueous hydrochloric acid. While adding the reaction solution little by little, white powder precipitates. This powder was filtered and dried to obtain polymer P-28 in a yield of 90%. The structure of this material was confirmed by NMR, IR and GPC.
This synthesis example is a synthesis example in which a modification treatment with an acid is performed after the polymerization step.
<Synthesis Example 3: Alkali-soluble polymer P-47>
In the flask, methyl methacrylate (0.295 mol), methacrylic acid (0.4 mol), methacrylamide (0.3 mol), compound I-1 (bifunctional crosslinker) (0.005 mol), V-601 (sum) A mixture of azo thermal polymerization initiator (0.006 mol) and N, N-dimethylacetamide (700 mL) manufactured by Kojunyaku Co., Ltd. is mixed and stirred at 80 ° C. for 5 hours. When the reaction solution is added little by little while stirring in 10 L of water, a white powder precipitates. The powder was filtered and dried to obtain polymer P-47 in a yield of 95%. The structure of this material was confirmed by NMR, IR and GPC.
This synthesis example is a synthesis example in which no modification was performed after the polymerization step.
In the same manner as described above, polymerization and, if desired, further modification with acid or base are performed, and the crosslinked structure-encapsulated alkali-soluble polymers (P-2) to (P-52) described in Tables 1 to 6 are obtained. Obtained.

  The comparative binder polymer (TP) used in the comparative example was synthesized in the same manner as the polymer (P) of the present invention except that no bifunctional cross-linking agent was added during synthesis. The polymer (P) is a polymer that contains each structural unit excluding the crosslinking component in substantially the same ratio and does not have a crosslinked structure. In the GPC profile, the polymer has only one peak in the polymer distribution. is there.

[Examples 1 to 21, Comparative Examples 1 to 19]
(Production 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 back coat coating solution 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 back coat layer having a coating amount of 70 mg / m ² after drying. Produced.

<Sol-gel reaction solution>
・ Tetraethyl silicate 50 mass parts ・ Water 20 mass parts ・ Methanol 15 mass parts ・ Phosphoric acid 0.05 mass parts

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

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

(Formation of recording layer)
On the aluminum support provided with the backcoat layer as described above, a photopolymerizable composition (recording layer coating solution) having the following composition was applied so that the dry coating amount was 1.5 g / m ^2, and 100 ° C. And dried for 1 minute to form a recording layer.

<Recording layer coating solution>
-Polymerizable compound (compound [R] described in Tables 10 to 12) 0.9 g
・ Binder polymer 1.1g
[Polymer of the present invention or comparative polymer, compounds described in Tables 10 to 12]
Sensitizing dye (compound [Y] described in Table 10 to Table 12) 0.3 g
-Polymerization initiator (compound [X] of Table 10-Table 12) 0.3g
・ Fluorine surfactant 0.03g
(Dai Nippon Ink Chemical Co., Ltd., MegaFuck F-780F)
・ N-phenyliminodiacetic acid 0.1g
・ Victoria Pure Blue Naphthalenesulfonate 0.04g
・ Methyl ethyl ketone 9.0g
・ Propylene glycol monomethyl ether 8.0g
・ Methanol 10.0g

(Formation of protective layer)
A 3% by weight aqueous solution of polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 550) was applied onto the recording layer so that the dry coating weight was 2 g / m ² and dried at 100 ° C. for 2 minutes for protection. A layer was provided.
As described above, lithographic printing plate precursors of Examples 1 to 21 and Comparative Examples 1 to 19 were produced.

(Exposure of planographic printing plate precursor)
The lithographic printing plate precursor obtained as described above was subjected to scanning exposure with a laser corresponding to each photosensitive material. Details of the exposure conditions are as follows.

(1) Lithographic printing plate precursors of Examples 1 to 7 and Comparative Examples 1 to 7 For the obtained lithographic printing plate precursors, an InGaN semiconductor laser with an oscillation wavelength of 400 nm was used, the beam system on the plate surface was 25 μm, and the exposure energy density Scanning exposure was performed under the condition of 0.15 mJ / cm ² .
(2) Lithographic printing plate precursors of Examples 8 to 11 and Comparative Examples 8 to 11 For the obtained lithographic printing plate precursors, an FD-YAG (532 nm) laser exposure machine (Heidenberg plate setter: Gutenberg) was used. The plate surface exposure energy density was 200 μJ / cm ² .

(3) Lithographic printing plate precursors of Examples 12 to 21 and Comparative Examples 12 to 19 A Crend Trendsetter 3244VFS equipped with a water-cooled 40 W infrared semiconductor laser (830 nm) on each of the obtained lithographic printing plate precursors, an output of 9 W The exposure was performed under the conditions of an outer drum rotating speed of 210 rpm, a plate surface energy of 100 mJ / cm ² , and a resolution of 2400 dpi.

(Development / plate making)
After exposure, the following developer and 1: 1 water dilution solution development of finisher Fuji Photo Film FN-6 were respectively charged into an automatic processor Stablon 900N manufactured by Fuji Photo Film Co., Ltd. and developed at 30 ° C. Plate making was performed to obtain a lithographic printing plate.

<Developer>
・ 800g of water
-DV-2 (Fuji Photo Film Co., Ltd.) 200g

[Evaluation]
(Image quality-evaluation of printing durability)
The obtained lithographic printing plate precursor was subjected to scanning exposure with a laser corresponding to each recording layer to form a 0.5% halftone dot (highlight), and after the exposure, developed with the developer. The photosensitive material obtained at this time was used as a printing plate, and after printing with a printing machine: Heidel KOR-D machine (manufactured by Heidelberg), the number of finished prints at which a good image was obtained was relatively compared as an index of printing durability. Here, Examples 1, 8, and 12 were expressed as printing durability indices based on the reference (200) in each exposure system according to the exposure wavelength. In production, the larger the index, the better the printing durability, which is preferable. A large number indicates that the printing durability in a high-definition highlight area is good, a substantially good image quality image is formed, and the printing durability in minute image areas such as halftone dots is excellent. It is an indicator of the balance between image quality and printing durability.

(Evaluation of sensitivity)
Sensitivity evaluation was performed using each exposure light source shown above.
In the sensitivity evaluation experiment, the standard exposure amount was lowered when performing exposure using the light source, and the minimum exposure amount at which an image after development was formed was calculated as sensitivity. The evaluation results are expressed as relative sensitivities in which Examples 1, 8, and 12 are used as the reference (1.0) in each exposure system according to each exposure wavelength.
Here, the relative sensitivity is defined by the following equation.
(Relative sensitivity = Sensitivity of standard photosensitive material / sensitivity of target photosensitive material)
The relative sensitivity indicates that the higher the value, the higher the sensitivity.

(Evaluation of storage stability)
After the same pre-exposure sample used for sensitivity evaluation was stored at 60 ° C. for 4 months, the sensitivity was evaluated in the same manner, and the sensitivity fluctuation ratio with the evaluation result of the sample before storage was calculated by the following formula. . This sensitivity fluctuation ratio was used as an index of storage stability. The value with no sensitivity variation is 1.0, and the closer to the numerical value, the better the storage stability.
Sensitivity fluctuation ratio = [(sensitivity before storage) / (sensitivity after storage at 60 ° C. for 4 months)]

  The evaluation results are shown in Table 10 for Examples 1-7 and Comparative Examples 1-7, in Table 11 for Examples 8-11 and Comparative Examples 8-11, and in Examples 12-21 and Comparative Examples 12-19. Is shown in Table 12.

  Here, the structures of polymerization initiators (X-1 to X-4), sensitizing dyes (Y-1 to Y-6), and polymerizable compounds (R-1 to R-4) in Tables 10 to 12 Is shown below.

  As is apparent from Tables 10 to 12, the lithographic printing plate precursor provided with a recording layer comprising the polymerizable composition of the present invention containing a crosslinked structure-containing alkali-soluble polymer is capable of recording with high sensitivity, and has a halftone dot. It has been found that even in a minute image portion such as the above, it has excellent printing durability and good storage stability. For example, in contrast between Example 1 and Comparative Example 1, Example 8 and Comparative Example 8, and Example 12 and Comparative Example 12, even a binder polymer having the same structural unit has a crosslinked structure in the molecule. The lithographic printing plate precursor of the comparative example provided with a recording layer containing a non-polymer was compared with the example of the example provided with a recording layer containing a crosslinked structure inclusion polymer, printing durability, sensitivity, and storage stability at the halftone dot portion. It turns out that all of sex is low. Moreover, the same tendency was seen in any exposure wavelength of 400 nm to 840 nm.

  In particular, in comparison with the results of Examples 19 to 21 and Comparative Example 19, the polymer containing the polymer obtained in the range of addition ratio of the bifunctional crosslinking agent in the range of 0.1 to 3.0% by mass, In particular, it can be seen that the above-described performances are good and the crosslinked structure existing in the polymer structure is important.

Claims (6)

An alkali-soluble polymer having an intramolecular cross-linking structure formed by a bifunctional cross-linking agent having two radical polymerizable groups in the molecule. The alkali-soluble polymer according to claim 1, wherein the intramolecular cross-linked structure is an intramolecular cross-linked structure represented by the following general formula (I-1).

In general formula (I-1), Q represents a hydrocarbon linking group, and the linking group structure may have —O— or —CO ₂ —. X represents N—R ′, an O atom, or an S atom, where R ′ represents a hydrogen atom or an alkyl group. A polymerizable composition comprising the alkali-soluble polymer having an intramolecular crosslinked structure according to claim 1. An image recording material comprising a photosensitive layer containing the polymerizable composition according to claim 3 on a support. i) a bifunctional crosslinking agent having two radically polymerizable groups in the molecule; ii) a monofunctional radically polymerizable monomer; iii) a polymerization initiator; and iv) a radical in the presence of an organic solvent. A method for producing an alkali-soluble polymer, wherein a polymerization reaction is caused and progressed to produce a polymer having an intramolecular cross-linked structure. 6. The method for producing an alkali-soluble polymer according to claim 5, wherein the polymer having an intramolecular cross-linked structure generated by the radical polymerization reaction is further modified with an acid or a base.