JP4445825B2 - Polymerizable composition and planographic printing plate precursor using the same - Google Patents

Description

  The present invention relates to a negative-type polymerizable composition and a lithographic printing plate precursor using the composition for a photosensitive layer, and more specifically, a polymerizable composition that cures with high sensitivity by infrared laser exposure, and The present invention relates to a negative lithographic printing plate precursor that can be recorded with high sensitivity.

In recent years, the development of lasers has been remarkable. In particular, solid-state lasers and semiconductor lasers having a light emitting region from the near infrared region to the infrared region have been increasing in output and size. Therefore, these lasers are very useful as an exposure light source when directly making a plate from digital data such as a computer.
As an image recording medium using such a laser as an exposure light source, for example, a thermopolymerizable recording layer containing a photothermal conversion substance, a thermal polymerization initiator that generates radicals, and a thermopolymerizable resin is known. (For example, refer to Patent Document 1).
Usually, such a negative type image recording material uses a recording system in which a radical generated by light or heat is used as an initiator to cause a polymerization reaction, and a recording layer in an exposed portion is cured to form an image portion. Yes. Negative-type image forming materials have low image-forming properties and promote the curing reaction by polymerization compared to the positive type that causes the recording layer to be solubilized by the energy of infrared laser irradiation due to its image forming mechanism. In order to form a strong image portion, the heat treatment is generally performed before the development step. Examples of the negative image recording material subjected to such post-heating treatment include a recording material composed of a resol resin and a novolac resin (see, for example, Patent Document 2).
However, when general-purpose aluminum is used as the support, energy from infrared laser irradiation diffuses into the support with high thermal conductivity and is not efficiently used to start and accelerate the polymerization reaction that contributes to image formation. There was a problem that sufficient sensitivity could not be obtained.

For this reason, various technologies have been proposed for the purpose of achieving high sensitivity and high printing durability. For example, a compound having an ethylenically unsaturated double bond and absorption at a specific wavelength (550 to 850 nm). A chemical composition (for example, refer to Patent Document 3) containing a compound having a diaryl iodonium salt and a compound having an onium salt and a carboxylate ion and a radical change irreversibly. A heat-sensitive composition (see, for example, Patent Document 4) has been proposed. However, these polymerizable compositions containing various highly polar or highly reactive compounds have other components (mainly alkalis) present in the recording layer under severe aging conditions such as high temperature and high humidity. There is a problem in that an undesired interaction is formed and the solubility in an alkaline aqueous solution is lowered.
JP-A-8-108621 US Pat. No. 5,340,699 Japanese Examined Patent Publication No. 7-103171 JP 2001-261727 A

  The present invention has been made in consideration of the above-mentioned problems in the prior art, and an object of the present invention is to provide a polymerizable composition that can be polymerized and cured with high sensitivity by exposure. Another object of the present invention is to enable recording with high sensitivity by infrared laser exposure using the polymerizable composition as a photosensitive layer, and to suppress a decrease in alkali developability of non-image areas over time. Another object of the present invention is to provide a negative lithographic printing plate precursor having excellent storage stability.

As a result of intensive studies, the present inventors have found that the above object can be achieved by using an onium salt having a counter anion having a specific structure as a polymerization initiator of the polymerizable composition, and to complete the present invention. It came.
That is, the polymerizable composition of the present invention comprises (A) a photopolymerization initiator having a structure represented by the following general formula ( 2 ), (B) a compound having at least one ethylenically unsaturated bond capable of addition polymerization, (C It contains an infrared absorber and (D) a binder polymer.

In the general formula (2), ^{M +} represents an onium cation, X is -NR ³ or -S - represents a. R ^{1 to} R ³ each independently represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. A ² represents a monovalent substituent composed of a nonmetallic atom , and at least one of A ² , R ¹ , R ² , and R ³ has one or more carboxylic acid groups.
As a more preferred embodiment of the photopolymerization initiator having the structure of the general formula (2), a compound having a structure of the following general formula (3) can be mentioned.

In General Formula (3), M ⁺ , R ¹ and R ² have the same meanings as in General Formula (2). R ⁴ represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. Ar represents an aromatic group or a heterocyclic group , and at least one of Ar, R ¹ , R ² , and R ⁴ has one or more carboxylic acid groups.
As a more preferred embodiment of the photopolymerization initiator having the structure of the general formula (2), a compound having the structure of the following general formula (4) can be mentioned.

In General Formula (4), M ⁺ , Ar, R ¹ , R ² , and R ⁴ have the same meaning as in General Formula (3). R ⁵ represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. In the general formula (4), Ar, R ¹ , R ² , R ⁴ , and R ⁵ may or may not have a carboxylic acid group.
As the photopolymerization initiator according to the present invention, from the viewpoint of improving the decomposition rate of the onium cation, the structure represented by the general formula (2) is used, and the structure represented by the general formula (3) is more preferable. The structure represented by the general formula (4) is most preferable.
Moreover, it is preferable to contain the polymer which has a structural unit represented by the following general formula (i) in the polymeric composition of this invention as (D) binder polymer.

In the general formula (i), R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ contains two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. And represents a linking group having 2 to 82 atoms. A represents an oxygen atom or —NR ⁸ —, and R ⁸ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. n represents an integer of 1 to 5.

The lithographic printing plate precursor according to the invention is characterized in that a photosensitive layer comprising the above-described polymerizable composition of the invention is provided on a support.
In the planographic printing plate precursor, it is preferable that a protective layer is provided on the photosensitive layer.

Although the operation of the present invention is not clear, the following is presumed. The polymerizable composition of the present invention uses (A) a photopolymerization initiator having a structure represented by the general formula ( 2 ) (hereinafter referred to as “specific initiator” as appropriate), whereby the specific initiator itself It exhibits high polarity, can form a stable layer, and has an alkali-soluble group introduced into the counter-anion of the radical polymerization initiator, specifically, a function such as a carboxylic acid group or a salt thereof. High solubility.
Furthermore, in the case of an initiator having a known general onium salt structure, when it is stored under severe conditions such as high temperature and high humidity, as described above, other components present in the photosensitive layer, particularly a binder polymer the interaction is formed between the alkali-soluble group in, but would also be present which solubility in an alkaline aqueous solution tends to decrease, in the case of using a specific initiator according to the present invention, onium salts In the structure, it forms a high interaction with this specific counter anion and suppresses the formation of an undesired time-dependent interaction with other coexisting compounds, so that alkali solubility Can be suppressed.
In addition, since the specific initiator according to the present invention has a counter anion represented by the general formula ( 2 ), radicals are generated with high sensitivity by improving the decomposition rate of the onium cation, and further generated. It is considered that the polymerization initiation radical and the polymerization growth radical that have undergone radical chain transfer to the counter anion compound promote the polymerization reaction of the polymerizable compound, and these functions combine to achieve high sensitivity.

Therefore, when such a polymerizable composition of the present invention is used as a photosensitive layer (recording layer) of a lithographic printing plate precursor, the non-image area has good alkali developability and is subjected to severe conditions such as high temperature and high humidity. It is considered that even when the film is stored in a non-image area, the residual film formation is suppressed without lowering the alkali developability. In general, when a highly polar compound such as an onium salt is used as a radical polymerization initiator, the initiator is adsorbed to an aluminum substrate or the like as a support to generate a residual color in a non-image area. Although there is a tendency, the radical polymerization initiator has a counter anion represented by the general formula ( 2 ), so that the alkali solubility of the initiator itself is improved, and stains are generated in the non-image area. Is considered to be suppressed. Further, it is presumed that recording with high sensitivity is possible due to the above-described effect of promoting the polymerization reaction.

According to the present invention, a polymerizable composition that can be polymerized and cured with high sensitivity by exposure can be provided.
Further, by using the polymerizable composition of the present invention as a photosensitive layer, it is possible to record with high sensitivity by infrared laser exposure, and the deterioration of alkali developability of the non-image area with time is suppressed, so that the storage stability is improved. an effect called can provide a lithographic printing plate precursor excellent negative sexual.

The present invention will be described in detail below.
(Polymerizable composition)
The polymerizable composition of the present invention comprises (A) a photopolymerization initiator represented by the general formula ( 2 ), (B) a compound having at least one ethylenically unsaturated bond capable of addition polymerization, and (C) infrared absorption. And (D) a binder. Below, each compound which can be used for the polymeric composition of this invention is demonstrated one by one.
[(A) Photopolymerization initiator represented by formula ( 2 )]
First, the photopolymerization initiator represented by the following general formula ( 2 ), which is a characteristic component of the polymerizable composition of the present invention, will be described. This specific initiator is characterized by having an onium cation and having at least one carboxylic acid group in the counter anion.

In General Formula (2), M ⁺ represents an onium cation, and X represents —NR ³ — or —S — . R ^{1 to} R ³ each independently represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. A ² represents a monovalent substituent composed of a nonmetallic atom , and at least one of A ² , R ¹ , R ² , and R ³ has one or more carboxylic acid groups.
As a more preferred embodiment of the specific initiator, a compound having the structure of the following general formula (3) can be mentioned.

In General Formula (3), M ⁺ , R ¹ and R ² have the same meanings as in General Formula (2). R ⁴ represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. Ar represents an aromatic group or a heterocyclic group , and at least one of Ar, R ¹ , R ² , and R ⁴ has one or more carboxylic acid groups.
As a most preferred embodiment of the specific initiator, a compound having the structure of the following general formula (4) can be mentioned.

In the general formula (4), M ⁺ , Ar, R ¹ , R ² and R ⁴ have the same meanings as in the general formula (3). R ⁵ represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. In the general formula (4), Ar, R ¹ , R ² , R ⁴ , and R ⁵ may or may not have a carboxylic acid group.

In the general formula (2) to (4), wherein M ⁺ represents an onium cation, the M ^+, ammonium, sulfonium, phosphonium, iodonium, and the like azinium the like, iodonium salts, sulfonium salts preferably, sulfonium More preferred are salts. Among the sulfonium salts, most preferred are those having a triarylsulfonium salt structure in the cation moiety and having at least one electron withdrawing group in the aryl group.

In the general formulas ( 2 ) to (4), R ^{1 to} R ⁵ each independently represent a monovalent substituent composed of a hydrogen atom or a nonmetallic atom, and these represent a nonmetallic atom when they represent a substituent. Examples of monovalent substituents composed of halogen atom, amino group, substituted amino group, substituted carbonyl tomb, hydroxyl group, substituted oxy group, thiol group, thioether group, silyl group, nitro group, cyano group, alkyl Group, alkenyl group, aryl group, heterocyclic group, sulfo group, substituted sulfonyl group, sulfonate group, substituted sulfinyl group, phosphono group, substituted phosphono group, phosphonate group, substituted phosphonate group, etc. May further have a substituent.

R ^{1 to} R ⁵ are preferably a hydrogen atom, a methyl group, a methoxymethyl group, a chloromethyl group, an acetyloxymethyl group, or a methoxycarbonylmethyl group.

Examples of the alkyl group represented by R ^{1 to} R ⁵ include linear, branched or cyclic alkyl groups having 1 to 20 carbon atoms. Among these, a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, and a cyclic alkyl group having 5 to 10 carbon atoms are more preferable. Specific examples thereof include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group. , Eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group And 2-norbornyl group.

When the alkyl group represented by R ^{1 to} R ⁵ has a substituent (that is, a substituted alkyl group), the alkyl part of the substituted alkyl group includes hydrogen on the alkyl group having 1 to 20 carbon atoms described above. A divalent organic residue obtained by removing any one of the atoms can be exemplified, and the preferable range of the number of carbon atoms is the same as that of the alkyl group.

Preferable specific examples when R ^{1 to} R ⁵ are substituted alkyl groups include chloromethyl group, bromomethyl group, 2-chloroethyl group, trifluoromethyl group, methoxymethyl group, methoxycarbonylmethyl group, isopropoxymethyl group , Butoxymethyl group, s-butoxybutyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, acetyloxymethyl group, methylthiomethyl group, tolylthiomethyl group, pyridylmethyl group, tetramethylpiperidinylmethyl group N-acetyltetramethylpiperidinylmethyl group, trimethylsilylmethyl group, methoxyethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarba Iroxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxycarbonylbutyl Group, chlorophenoxycarbonylmethyl group,

Carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group Sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phosphonophenyl) sulfamoyl Octyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxy Propyl group, phosphona Oxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2- Examples thereof include a methylallyl group, a 2-methylpropenylmethyl group, a 2-propynyl group, a 2-butynyl group, and a 3-butynyl group.

Examples of the substituent that can be introduced into the alkyl group represented by R ^{1 to} R ⁵ include a monovalent composed of non-metal atoms exemplified below in addition to the substituents described in the description of the substituted alkyl group. Substituents are also included. Preferable examples including the above-described substituent include a halogen atom (—F, —Br, —Cl, —I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryl. Dithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-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 group, aryl A sulfoxy group, an acylthio group, an acylamino group, -Alkylacylamino group, N-arylacylamino group, ureido group, N'-alkylureido group, N ', N'-dialkylureido group, N'-arylureido group, N', N'-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N′-alkyl-N-arylureido group, N ′, N '-Dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N'-aryl-N-arylureido group, N ', N '-Diaryl-N-alkylureido group, N', N'-diaryl-N-arylureido group, N'-alkyl-N'-aryl-N-alkylureido group, N'-alkyl A ru-N′-aryl-N-arylureido group,

Alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N -Aryloxycarbonylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N- di arylcarbamoyl 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 (sul Nato group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinaimoyl group, N-arylsulfinamoyl group, N, N-diaryl Sulfinamoyl 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,

A phosphono group (—PO ₃ H ₂ ) and its conjugate base group (referred to as a phosphonate group), a dialkylphosphono group (—PO ₃ (alkyl) ₂ ) “alkyl = alkyl group, the same shall apply hereinafter”, a diarylphosphono group ( -PO ₃ (aryl) ₂ ) “aryl = aryl group, hereinafter the same”, alkylarylphosphono group (—PO ₃ (alkyl) (aryl)), monoalkylphosphono group (—PO ₃ (alkyl)) and its Conjugated base group (referred to as alkylphosphonate group), monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group (referred to as arylphosphonate group), phosphonooxy group (—OPO ₃ H ₂₎ ) and (referred to as phosphonatooxy group), dialkylphosphono group (-OPO ₃ H (alkyl) its conjugate base group _2), diarylphosphono Alkoxy group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphono group _{(-OPO 3 (alkyl) (aryl} )), monoalkyl phosphono group (-OPO ₃ H (alkyl)) and its conjugated base group (Referred to as alkylphosphonatoxy group), monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group (referred to as arylphosphonatoxy group), cyano group, nitro group, aryl group Alkenyl group, alkynyl group, heterocyclic group, silyl group, and the like.

Specific examples of the alkyl moiety in the substituent that can be introduced into the alkyl group represented by R ^{1 to} R ⁵ are the same as those in the case where R ^{1 to} R ³ described above are substituted alkyl groups, and the preferred ranges are also the same. is there.
Specific examples of the aryl moiety in the substituent that can be introduced into the alkyl group represented by R ^{1 to} R ⁵ include a phenyl group, a biphenyl group, a naphthyl group, a tolyl group, a xylyl group, a mesityl group, a cumenyl group, and a chlorophenyl group. Group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group Dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, cyanophenyl group, sulfone Group, a sulfophenyl group, phosphono phenyl group, phosphonium Hona preparative phenyl group, and the like.

Examples of the alkenyl group represented by R ^{1 to} R ⁵ include alkenyl groups having 2 to 20 carbon atoms. Among these, an alkenyl group having 2 to 10 carbon atoms is preferable, and an alkenyl group having 2 to 8 carbon atoms is more preferable. The alkenyl group may further have a substituent. Examples of the substituent that can be introduced include a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group. A cyclic alkyl group is preferred. Specific examples of the alkenyl group include, for example, vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group, 1-pentenyl group, 1-hexenyl group, 1-octenyl group, 1-methyl-1-propenyl group, A 2-methyl-1-propenyl group, a 2-methyl-1-butenyl group, a 2-phenyl-1-ethenyl group, a 2-chloro-1-ethenyl group, and the like can be given.

Examples of the alkynyl group represented by R ^{1 to} R ⁵ include alkynyl groups having 2 to 20 carbon atoms. Among these, an alkynyl group having 2 to 10 carbon atoms is preferable, and an alkynyl group having 2 to 8 carbon atoms is more preferable. Specific examples thereof include ethynyl group, 1-propynyl group, 1-butynyl group, phenylethynyl group, trimethylsilylethynyl group and the like.

Examples of the aryl group represented by R ^{1 to} R ⁵ include a benzene ring, a group in which 2 to 3 benzene rings form a condensed ring, and a group in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. be able to. Specific examples thereof include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable.

When the aryl group represented by R ¹ to R ⁵ has a substituent (i.e., if a substituted aryl group), examples of the substituent the aryl group, as a substituent on the ring-forming carbon atoms, composed of non-metallic atoms And those having a monovalent substituent. Preferable examples of the substituent to be introduced include those described in the above description of the alkyl group, the substituted alkyl group, and the substituent in the substituted alkyl group.

Preferred examples when R ^{1 to} R ⁵ are substituted aryl groups include biphenyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, fluorophenyl group, chloromethylphenyl group, Trifluoromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl group, phenoxyphenyl group, methylthiophenyl group, tolylthiophenyl group, ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, Acetyloxyphenyl group, benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group, acetylaminophenyl group, N-methylbenzoylaminopheny Group, carboxyphenyl group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, carbamoylphenyl group, N-methylcarbamoylphenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) Carbamoylphenyl group, N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfamoyl Phenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, phosphonophenyl group, phosphonatophenyl group, diethylphosphonophenyl group, diphenylphosphono Phenyl group, methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonatophenyl group, allylphenyl group, 1-propenylmethylphenyl group, 2-butenylphenyl group, 2-methylallylphenyl Group, 2-methylpropenylphenyl group, 2-propynylphenyl group, 2-butynylphenyl group, 3-butynylphenyl group and the like. Among these, a biphenyl group, a tolyl group, a xylyl group, a mesityl group, a chlorophenyl group and the like are preferable.

The heterocyclic group represented by R ^{1 to} R ⁵ is preferably a 3- to 8-membered heterocyclic group, more preferably a 3- to 6-membered heterocyclic group containing a nitrogen atom, an oxygen atom, or a sulfur atom. A 5- to 6-membered heterocyclic group containing a nitrogen atom, oxygen atom or sulfur atom is more preferred. Specific examples thereof include a pyridyl group and a piperidinyl group.

The silyl group represented by R ^{1 to} R ⁵ may have a substituent, preferably a silyl group having 0 to 30 carbon atoms, more preferably a silyl group having 3 to 20 carbon atoms, and 3 carbon atoms. To 10 silyl groups are more preferred. Specific examples thereof include a trimethylsilyl group, a triethylsilylyl group, a tripropylsilyl group, a triisopropylsilyl group, a cyclohexyldimethylsilyl group, and a dimethylvinylsilyl group .

As the thiol group represented by R ^{1 to} R ⁵ , the thiol group represented by R ^{1 to} R ³ may have a substituent, preferably a thiol group having 0 to 30 carbon atoms, A thiol group having 3 to 20 carbon atoms is more preferable, and a thiol group having 1 to 10 carbon atoms is more preferable. Specific examples thereof include a mercaptomethyl group, a mercaptoethyl group, a 4-mercaptocyclohexyl group, and a 4-mercaptophenyl group.

The thioether group represented by R ^{1 to} R ⁵ may have a substituent, preferably a thioether group having 0 to 30 carbon atoms, more preferably a thioether group having 3 to 20 carbon atoms, A thioether group having a number of 1 to 10 is more preferable.
Specific examples thereof include alkylthio groups such as methylthio group, ethylthio group and cyclohexylthio group, arylthio groups such as phenylthio group, and the like.
Examples of the halogen atom represented by R ^{1 to} R ³ include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom. Among these, a chlorine atom and a bromine atom are preferable.

The substituted oxy group (R ⁰⁶ O-), can be used a group R ⁰⁶ is a monovalent nonmetallic atom group exclusive of a hydrogen atom. Preferred substituted oxy groups include alkoxy groups, aryloxy groups, acyloxy groups, carbamoyloxy groups, N-alkylcarbamoyloxy groups, N-arylcarbamoyloxy groups, N, N-dialkylcarbamoyloxy groups, N, N-diarylcarbamoyloxy groups. Groups, N-alkyl-N-arylcarbamoyloxy groups, alkylsulfoxy groups, arylsulfoxy groups, phosphonooxy groups, and phosphonatoxy groups. Examples of the alkyl group and aryl group in these include the alkyl groups, substituted alkyl groups, aryl groups, and substituted aryl groups described above. Examples of the acyl group (R ⁰⁷ CO—) in the acyloxy group include those in which R ⁰⁷ is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group mentioned as the previous example. Among these substituents, an alkoxy group, an aryloxy group, an acyloxy group, and an arylsulfoxy group are more preferable. Specific examples of preferred substituted oxy groups include methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, pentyloxy, hexyloxy, dodecyloxy, benzyloxy, allyloxy, phenethyloxy, Carboxyethyloxy group, methoxycarbonylethyloxy group, ethoxycarbonylethyloxy group, methoxyethoxy group, phenoxyethoxy group, methoxyethoxyethoxy group, ethoxyethoxyethoxy group, morpholinoethoxy group, morpholinopropyloxy group, allyloxyethoxyethoxy group, Phenoxy group, tolyloxy group, xylyloxy group, mesityloxy group, mesityloxy group, cumenyloxy group, methoxyphenyloxy group, ethoxyphenyloxy group, chlorophenyl Alkoxy group, bromophenyl group, acetyloxy group, benzoyloxy group, naphthyloxy group, a phenylsulfonyloxy group, a phosphonooxy group, phosphonatoxy group, and the like.

The amino group may be a substituted amino group including an amide group. The substituted amino group (R ⁰⁸ NH—, (R ⁰⁹ ) (R ⁰¹⁰ ) N—) including an amide group is a group in which R ⁰⁸ , R ⁰⁹ , and R ⁰¹⁰ are monovalent nonmetallic atomic groups excluding hydrogen atoms Can be used. R ⁰⁹ and R ⁰¹⁰ may be bonded to form a ring. Preferred examples of the substituted amino group include an N-alkylamino group, an N, N-dialkylamino group, an N-arylamino group, an N, N-diarylamino group, an N-alkyl-N-arylamino group, an acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N′-alkyl-N-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N′-alkyl-N′-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, '-Dialkyl-N'-arylureido group, N'-aryl-N-alkylureido group, N'-aryl-N-arylureido group, N', N'-diaryl-N-alkylureido group, N ', N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxy A carbonylamino group, an N-alkyl-N-alkoxycarbonylamino group, an N-alkyl-N-aryloxycarbonylamino group, an N-aryl-N-alkoxycarbonylamino group, and an N-aryl-N-aryloxycarbonylamino group. Can be mentioned. Examples of the alkyl group and aryl group include those described above as the alkyl group, substituted alkyl group, aryl group, and substituted aryl group, such as acylamino group, N-alkylacylamino group, and N-arylacylamino. R ⁰⁷ groups definitive acyl group (R ⁰⁷ CO-) are as described above. Of these, more preferred are an N-alkylamino group, an N, N-dialkylamino group, an N-arylamino group, and an acylamino group. Specific examples of preferred substituted amino groups include methylamino group, ethylamino group, diethylamino group, morpholino group, piperidino group, pyrrolidino group, phenylamino group, benzoylamino group, acetylamino group and the like.

As the substituted sulfonyl group (R ⁰¹¹ —SO ₂ —), those in which R ⁰¹¹ is a group composed of a monovalent nonmetallic atomic group can be used. More preferable examples include an alkylsulfonyl group, an arylsulfonyl group, and a substituted or unsubstituted sulfamoyl group. Examples of the alkyl group and aryl group in these include those described above as the alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Specific examples of such a substituted sulfonyl group include butylsulfonyl group, phenylsulfonyl group, chlorophenylsulfonyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfuryl group. A famoyl group, an N-alkyl-N-arylsulfamoyl group, and the like.

As described above, the sulfonate group (—SO ₃ —) means a conjugate base anion group of the sulfo group (—SO ₃ H), and is usually preferably used together with a counter cation. Such counter cations include those generally known, that is, various oniums (ammonium, sulfonium, phosphonium, iodonium, azinium, etc.) and metal ions (Na ⁺ , K +, Ca ^{2). +} , Zn ^2+, etc.).

As the substituted carbonyl group (R ⁰¹³ —CO—), those in which R ⁰¹³ is a group composed of a monovalent nonmetallic atomic group can be used. Preferred examples of the substituted carbonyl group include formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N′-arylcarbamoyl group may be mentioned. Examples of the alkyl group and aryl group in these include those described above as the alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Among these, more preferred substituted carbonyl groups include formyl, acyl, carboxyl, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, N-alkylcarbamoyl, N, N-dialkylcarbamoyl, N-ary. A rucarbamoyl group can be mentioned, and even more preferred are a formyl group, an acyl group, an alkoxycarbonyl group and an aryloxycarbonyl group. Specific examples of preferred substituted carbonyl groups include formyl group, acetyl group, benzoyl group, carboxyl group, methoxycarbonyl group, ethoxycarbonyl group, allyloxycarbonyl group, dimethylaminophenylethenylcarbonyl group, methoxycarbonylmethoxycarbonyl group, N -Methylcarbamoyl group, N-phenylcarbamoyl group, N, N-diethylcarbamoyl group, morpholinocarbonyl group and the like.

As the substituted sulfinyl group (R ⁰¹⁴ —SO—), a group in which R ⁰¹⁴ is a monovalent nonmetallic atomic group can be used. Preferred examples include alkylsulfinyl group, arylsulfinyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl. Group, N-alkyl-N-arylsulfinamoyl group. Examples of the alkyl group and aryl group in these include those described above as the alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Of these, more preferred examples include an alkylsulfinyl group and an arylsulfinyl group. Specific examples of such a substituted sulfinyl group include a hexylsulfinyl group, a benzylsulfinyl group, and a tolylsulfinyl group.

  The substituted phosphono group means a group in which one or two hydroxyl groups on the phosphono group are substituted with other organic oxo groups, and preferred examples thereof include the above-mentioned dialkylphosphono group, diarylphosphono group, alkylarylphospho group. Group, monoalkylphosphono group and monoarylphosphono group. Of these, dialkylphosphono groups and diarylphosphono groups are more preferred. Specific examples thereof include a diethyl phosphono group, a dibutyl phosphono group, a diphenyl phosphono group, and the like.

Phosphonato group _{(-PO 3 H 2 -, -} PO 3 H-) and the meaning of a phosphono group (-PO ₃ H _2), first dissociation or acid, a conjugated base anion group derived from the second dissociation acid To do. Usually, it is preferable to use it with a counter cation. Such counter cations include those generally known, that is, various oniums (ammonium, sulfonium, phosphonium, iodonium, azinium, etc.), and metal ions (Na ⁺ , K ⁺ , Ca ²⁺ , Zn ^{2+ and the} like).

The substituted phosphonato group is a conjugated base anion group obtained by substituting one organic oxo group in the above-described substituted phosphono group. As a specific example, the above-described monoalkylphosphono group (—PO ₃ H ( alkyl)), and a conjugate base of a monoarylphosphono group (—PO ₃ H (aryl)).

  Ar represents an aromatic group or a heterocyclic group. Examples of the aromatic group include a benzene ring, two to three benzene rings forming a condensed ring, a benzene ring and a 5-membered unsaturated ring. Those having a condensed ring are exemplified. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable.

  In addition, the aromatic group represented by Ar may have a substituent on the carbon atom forming the ring, and as such a substituent, a monovalent substituent composed of a nonmetallic atom. Is mentioned. Preferable examples of the substituent to be introduced include those described above in the description of the alkyl group, the substituted alkyl group, and the substituent in the substituted alkyl group.

  The heterocyclic group represented by Ar is preferably a 3-membered to 9-membered heterocyclic group, more preferably a 3-membered to 6-membered heterocyclic group containing a nitrogen atom, an oxygen atom, or a sulfur atom, A 5- to 6-membered heterocyclic group containing a nitrogen atom, an oxygen atom, or a sulfur atom is more preferred. Specific examples thereof include pyrrole ring group, furan ring group, thiophene ring group, benzopyrrole ring group, benzofuran ring group, benzothiophene ring group, pyrazole ring group, isoxazole ring group, isothiazole ring group, indazole ring group, benzo Isoxazole ring group, benzoisothiazole ring group, imidazole ring group, oxazole ring group, thiazole ring group, benzimidazole ring group, benzoxazole ring group, benzothiazole ring group, pyridine ring group, quinoline ring group, isoquinoline ring group , Pyridazine ring group, pyrimidine ring group, pyrazine ring group, phthalazine ring group, quinazoline ring group, quinoxaline ring group, acylidine ring group, phenanthridine ring group, carbazole ring group, purine ring group, pyran ring group, piperidine ring group , Piperazine ring group, morpholine ring group, indole ring group, indoli Ring group, a chromene ring group, a cinnoline ring group, an acridine ring group, a phenothiazine ring group, a tetrazole ring group, a triazine ring group, and the like.

  Moreover, the heterocyclic group represented by Ar may have a substituent on the carbon atom forming the ring, and as such a substituent, a monovalent substituent composed of a nonmetallic atom is used. Is mentioned. Preferable examples of the substituent to be introduced include those described above in the description of the alkyl group, the substituted alkyl group, and the substituent in the substituted alkyl group.

R ^{1 to} R ⁵ and Ar may be bonded to each other to form a hydrocarbon ring and a condensed ring of a benzene ring / heterocycle together with the carbon atom to which they are bonded.
Next, a preferred embodiment of R ^{1 to} R ⁵ will be described. As R ¹ and R ² , a hydrogen atom and an alkyl group which may have a substituent having 1 to 20 carbon atoms are preferable, and a hydrogen atom and carbon number 1 are preferable. An alkyl group that may have 10 to 10 substituents is more preferable, and an alkyl group that may have a hydrogen atom and a substituent having 1 to 6 carbon atoms is more preferable. Moreover, it is most preferable that both R ¹ and R ² are hydrogen atoms from the viewpoint of the above-described polymerization promoting function.
R ⁴ and R ⁵ are preferably an alkyl group, an aromatic group or a heterocyclic group which may have a substituent having 1 to 20 carbon atoms, and an alkyl which may have a substituent having 1 to 10 carbon atoms. A group, an aromatic group, and a heterocyclic group are more preferable, and an alkyl group, an aromatic group, and a heterocyclic group that may have a C1-C10 substituent containing an alkali-soluble group are more preferable.

Ar is preferably a benzene ring, two to three benzene rings forming a condensed ring, or a benzene ring and a five-membered unsaturated ring forming a condensed ring, specifically a phenyl group, naphthyl Group, anthryl group, phenanthryl group, indenyl group, acenaphthenyl group, and fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable.
As X, —NR ³ — and —NR ³ — are most preferable among —NR ³ — and —S— from the viewpoint of sensitivity.
Specific examples of the specific initiator represented by the general formula ( 2 ) used in the present invention are listed below, but the scope of the present invention is not limited thereto. [Exemplary compounds (S-1) , (S-9), (S-10), (S-12), (S-16), (S-17), (S-19) to (S-19) to (S-)] 24), (S-26) to (S-29), (S-31), (S-32), (S-34) to (S-39), (S-41), (S-43) To (S-45)] is a sulfonium salt compound, [Exemplary compounds (I-1) , (I-9), (I-10), (I-12) to (I-15), (I-17)] To (I-19), (I-21), (I-23), (I-26) to (I- 29 )] are iodonium salt compounds, [Exemplary compounds (N-1) to (N-4) , (N-6), (N- 7 )] are ammonium salt compounds.

<Synthesis Example of Exemplary Compound (S-16)>
1. Synthesis of triphenylsulfonium bromide 7.8 g of diphenylsulfoxide was dissolved in 100 mL of tetrahydrofuran (THF), and 40 mL of phenylmagnesium bromide in THF (1.02 mol / L) was added dropwise to the reaction solution under ice cooling. 9.08 g of chloride was added dropwise and stirred for 30 minutes at room temperature. The reaction solution was quenched with hydrobromic acid, and the organic layer was extracted with methylene chloride and dried to obtain 10.3 g of triphenylsulfonium bromide.

2. Synthesis of Exemplary Compound (S-16) 6 g of triphenylsulfonium bromide was dissolved in 100 mL of methanol, and 4.6 g of silver oxide was added to this solution, followed by stirring at room temperature for 4 hours. The solution was filtered, and 4.2 g of N-phenyliminodiacetic acid was added thereto. The reaction solution was concentrated, the concentrate was reslurried with hexane, acetone and diisopropyl ether, and the supernatant was decanted and vacuum dried to obtain 6.8 g of (A-16).

The (A) specific initiator according to the present invention may be used alone or in combination of two or more.
As content of the specific initiator contained in the polymeric composition of this invention, it is preferable that it is 0.1-30 mass% in polymeric composition total solid, and is 1-20 mass%. More preferably, the content is 2 to 10% by mass.
Moreover, you may use together other radical polymerization initiators other than the said specific initiator with the polymeric composition of this invention. As other radical polymerization initiators that can be used in combination, radicals are generated by the energy of light and / or heat, and the polymerization reaction of the compound (B) having an ethylenically unsaturated bond capable of addition polymerization described below is initiated and accelerated. If it is a compound to be, there is no restriction | limiting in particular.
Examples of the mother structure of the specific initiator that does not contain the alkali-soluble group include conventionally known thermal polymerization initiators, photopolymerization initiators, compounds having a bond with small bond dissociation energy, and the like. Common radical polymerization initiators listed in paragraphs [0052] to [0080] of Japanese Patent Application No. 2003-202961 previously filed by the applicant of the present application can be mentioned, and the content thereof is a specific start. It is preferable that it is 0-50 mass% in all the radical polymerization initiators containing an agent, It is more preferable that it is 0-30 mass%, It is most preferable that it is 0-15 mass%.

  Specific examples of polymerization initiators that can be used in combination include organic halogenated compounds, carbonyl compounds, organic peroxide compounds, azo polymerization initiators, azide compounds, metallocene compounds, hexaarylbiimidazole compounds, organic boric acid compounds, Examples thereof include disulfonic acid compounds and oxime ester compounds. Among them, from the viewpoints of reactivity and stability, organic halogenated compounds, organic boronic acid compounds, and oxime ester compounds are preferable, and organic halogenated compounds and organic boronic acid compounds are preferred. More preferred.

[(B) Compound having at least one ethylenically unsaturated bond capable of addition polymerization]
The compound (B) used in the present invention having at least one addition-polymerizable ethylenically unsaturated bond (hereinafter referred to as “polymerizable compound” as appropriate) has at least one ethylenically unsaturated double bond. The addition-polymerizable compound is preferably selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These include, for example, those having chemical forms such as monomers, prepolymers, that is, dimers, trimers and oligomers, or mixtures thereof and copolymers thereof.

  Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), and esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, unsaturated carboxylic acid ester having a nucleophilic substituent such as hydroxyl group, amino group, mercapto group, amide and monofunctional or polyfunctional isocyanate, addition reaction product of epoxy, monofunctional or A dehydration condensation reaction product with a polyfunctional carboxylic acid is also preferably used.

  In addition, an unsaturated carboxylic acid ester having an electrophilic substituent such as an isocyanate group or an epoxy group, an addition reaction product of an amide with a monofunctional or polyfunctional alcohol, amine or thiol, halogen A substitution reaction product of an unsaturated carboxylic acid ester or amide with a monofunctional or polyfunctional alcohol, amine or thiol having a leaving group such as a group or a tosyloxy group is also suitable. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, polypropylene glycol diacrylate, and the like.

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

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

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

  Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, and JP-A-59-5240. And those having an aromatic skeleton described in JP-A-59-5241, JP-A-2-226149, and those containing an amino group described in JP-A-1-165613. Used.
Furthermore, the ester monomers described above can also be used as a mixture.

Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.
Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

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

In the general formula (g), R and R ′ each independently represents a hydrogen atom or CH ₃ .
Further, urethane acrylates as described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56-17654 And urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418.

  Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the case, a polymerizable composition having an excellent curing reaction rate can be obtained.

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

  For these compounds (B) having an ethylenically unsaturated bond, details of how to use such as what structure is used, whether they are used alone or in combination, and how much is added, are the final photosensitive materials It can be set arbitrarily according to the performance design. For example, it is selected from the following viewpoints. From the viewpoint of photosensitive speed, a structure having a high unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image area, that is, the cured film, those having three or more functionalities are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrenic compound, vinyl ether). It is also effective to adjust both photosensitivity and strength by using a compound of the type). A compound having a large molecular weight or a compound having a high hydrophobicity is not preferable in terms of development speed and precipitation in a developing solution, although it is excellent in photosensitive speed and film strength.

(B) Regarding the compounding ratio of the polymerizable compound, a larger amount is more advantageous in terms of sensitivity, but if it is too much, an undesirable phase separation occurs or a problem in the production process due to the adhesiveness of the composition (for example, When the polymerizable composition of the present invention is used for the photosensitive layer of a lithographic printing plate precursor, problems such as precipitation from the developer may occur. From these viewpoints, the component (B) in the polymerizable composition of the present invention is similarly 20 to 70 masses with respect to the total solid content of the polymerizable composition when it is used for the recording layer of the lithographic printing plate precursor. % Is preferable, and 25 to 50% by mass is more preferable.
Moreover, (B) polymeric compound may be used individually by 1 type, and may be used together 2 or more types.

  In addition, when used for a lithographic printing plate precursor, the selection of (B) polymerizable compound is also required for compatibility and dispersibility with other components in the recording layer (for example, binder polymer, initiator, colorant, etc.). -Usage is an important factor. For example, compatibility may be improved by using low-purity compounds or using two or more kinds in combination.

[(C) Infrared absorber]
The (C) infrared absorber used in the present invention is preferably a compound having absorption at a wavelength of 700 to 1300 nm, and has an absorption maximum at a wavelength of 760 to 1200 nm from the viewpoint of compatibility with an easily available high-power laser. It is preferable that it is an infrared-absorbing dye or pigment. By adding such an infrared absorber, the polymerizable composition of the present invention has sensitivity in the infrared wavelength region.

  Spectral sensitizing dyes or dyes preferred as (C) infrared absorbers used in the present invention include 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.

More preferable spectral sensitizing dyes or dyes include compounds described in the following publications.
The pyrylium salts described in Japanese Patent Publication No. 40-28499, for example, the following compounds may be mentioned.

  Examples of the cyanines described in JP-B No. 46-42363 include the following compounds.

  Examples of the benzofuran dye described in JP-A-2-63053 include the following compounds.

  Examples of the conjugated ketone dyes disclosed in JP-A-2-85858 and JP-A-2-216154 include the following compounds.

  Examples thereof include dyes described in JP-A 57-10605 and azocinnamylidene derivatives described in JP-B-2-30321, such as the following compounds.

  Examples of the cyanine dyes described in JP-A-1-287105 include the following compounds.

  Examples of the xanthene dyes described in JP-A Nos. 62-31844, 62-31848, and 62-143043 include the following compounds.

  Aminostyryl ketone described in JP-B-59-28325, for example, the following compounds may be mentioned.

  The following infrared absorbers (dyes or pigments) are also preferably used as sensitizing dyes. Preferred examples of the dye include cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, and the like. Examples include cyanine dyes described in Japanese Patent No. 434,875.

  In addition, as cyanine dyes that can be suitably used in the present invention, paragraph numbers [0017] to [0019] of JP-A No. 2001-133969, paragraph numbers [0012] to [0038] of JP-A No. 2002-40638, Those described in paragraph numbers [0012] to [0023] of JP-A-2002-23360 can be mentioned. Specific examples include those exemplified below.

  Further, a near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and further, a substituted arylbenzoate described in US Pat. No. 3,881,924 is 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 It is described in the pentamethine thiopyrylium salt described in Japanese Patent No. 4,283,475, and Japanese Patent Publication Nos. 5-13514 and 5-19702. Pyrylium compounds are also preferably used.

  In addition, the near-infrared absorbing dyes described as formulas (I) and (II) in US Pat. No. 4,756,993 and the 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. For example, (b) anionic metal complex, (b) anionic carbon black, (c) anionic phthalocyanine, and (d) a compound represented by the following general formula (i). The counter cation of these anionic infrared absorbers is a monovalent cation containing a proton or a polyvalent cation.

Here, (a) an anionic metal complex refers to an anion formed by the central metal of the complex part that substantially absorbs light and the entire ligand.

  (B) Examples of the 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.

  (C) Anionic phthalocyanine refers to a phthalocyanine skeleton having the anion group previously mentioned in the description of (b) as a substituent bonded to form an anion as a whole.

Next, (d) the compound represented by the general formula (i) will be described in detail. In the general formula (i), 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 (i), 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 ⁻ ), alkylsulfonate anion, and arylsulfonate 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 preferred anionic infrared absorber, and IRC-7, IRC-30, IRC-40, and IRC-42 are nonionic infrared absorbers as cationic infrared absorbers. As IRN-9.

<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” (Yokoshobo), “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 recording layer coating solution, and when it exceeds 10 μm, it is not preferable from the viewpoint of uniformity of the 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).

In addition, although (C) infrared absorber added in order to accelerate | stimulate hardening reaction of the polymeric composition of this invention may be added directly with another component in a composition, another layer adjacent to this may be added. Even if it is provided and added thereto, the same effect can be obtained. Moreover, only 1 type may be used for the (C) infrared absorber in this invention, and it can also use 2 or more types together.
In particular, when the polymerizable composition of the present invention is used as a material for a negative recording layer of an image recording material described later, it may be added to the same layer as the recording layer, or another layer is provided there. Although it may be added, when a negative image recording material is produced, the optical density at the absorption maximum in the wavelength range of 300 nm to 1200 nm of the recording layer is between 0.1 and 3.0. It is preferable from the viewpoint of sensitivity. 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.
In addition, as the content of the infrared absorber in the polymerizable composition of the present invention, when applied to a recording layer such as an image recording material, the content is also 0.01 to the total solid content of the polymerizable composition. 20 mass% is preferable, and within this range, the polymerizable composition of the present invention is excellent in uniformity of the composition, is cured with high sensitivity, and achieves excellent film properties. Moreover, 0.01-10 mass% is more preferable, and 0.02-5 mass% is especially preferable.

[(D) Binder]
The polymerizable composition of the present invention needs to contain (D) a binder polymer from the viewpoint of improving film properties. (D) It is preferable to use a linear organic polymer as the binder polymer. Any polymer compound may be used as long as it is such a “linear organic polymer”, but it is preferably soluble in water or weak alkaline water that enables water development or weak alkaline water development. Or a linear organic polymer that can swell.
The linear organic high molecular polymer is selected and used not only as a film-forming agent for the composition but also according to its use as water, weak alkaline water or an organic solvent developer. For example, when a water-soluble organic polymer is used, water development is possible. Examples of such a linear organic polymer include addition polymers having a carboxylic acid group in the side chain, such as JP-A-59-44615, JP-B-54-34327, JP-B-58-12777, JP-A-54-25957, JP-A-54-92723, JP-A-59-53836, JP-A-59-71048, and the special features previously proposed by the applicant of the present application. Those described in Japanese Patent Application No. 2002-287920, that is, a methacrylic acid copolymer, an acrylic acid copolymer, an itaconic acid copolymer, a crotonic acid copolymer, a maleic acid copolymer, and a partially esterified malein Examples include acid copolymers, 2-methacryloyloxyethyl succinic acid copolymers, and 2-methacryloyloxyethyl hexahydrophthalic acid copolymers. Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group are useful.

  Among them, from the viewpoint of suppressing damage by the developer, Japanese Patent Application No. 2002-287920 (D) binder polymer such as 2-methacryloyloxyethyl succinic acid copolymer, 2-methacryloyloxyethyl hexahydrophthalic acid copolymer, etc. It is preferable to contain the polymer which has the structural unit represented by the following general formula (i) described in the specification.

In the general formula (i), R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ contains two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. And represents a linking group having 2 to 82 atoms. A represents an oxygen atom or —NR ⁸ —, and R ⁸ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. n represents an integer of 1 to 5.
In the general formula (i), it is more preferable that the linking group represented by R ⁷ has an alkylene structure, or a structure in which the alkylene structure is linked via an ester bond.

Hereinafter, the structural unit represented by the general formula (i) will be described in detail.
R ⁶ in the general formula (i) represents a hydrogen atom or a methyl group, and a methyl group is particularly preferable.
The linking group represented by R ⁷ in the general formula (i) represents a linking group composed of one or more atoms selected from the group consisting 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 2-30. 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 ⁷ in the general formula (i) is preferably an (n + 1) -valent hydrocarbon group having an aliphatic cyclic structure having 3 to 30 carbon atoms. 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 And (n + 1) valent hydrocarbon groups by removing (n + 1) hydrogen atoms on an arbitrary carbon atom constituting. R ⁷ preferably has 3 to 30 carbon atoms including a substituent.

One or more arbitrary carbon atoms of the compound constituting the aliphatic cyclic structure may be replaced with a heteroatom selected from a nitrogen atom, an oxygen atom, or a sulfur atom. In terms of printing durability, R ⁷ is a condensed polycyclic aliphatic hydrocarbon, a bridged cyclic aliphatic hydrocarbon, a spiro aliphatic hydrocarbon, an aliphatic hydrocarbon ring assembly (a plurality of rings are connected by a bond or a linking group). A (n + 1) valent hydrocarbon group having an aliphatic cyclic structure which may have a substituent of 5 to 30 carbon atoms containing two or more rings. . Also in this case, the carbon number includes the carbon atom of the substituent.

As the linking group represented by R ⁷ , those having 5 to 10 atoms are further preferred, and structurally a chain structure having an ester bond in the structure, Those having a cyclic structure are preferred.

Examples of the substituent that can be introduced into the linking group represented by R ⁷ 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, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-aryl Ureido 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'-al Kill-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group 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, 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- Dialkylsulfinamoyl group, N-arylsulfinamoyl 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 conjugated base group, N- aryl sulfonylsulfamoyl group _{(-SO 2 NHSO 2 (aryl)} ) and its conjugated base group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ (alkyl)) and its conjugate Base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ (aryl)) and its conjugate base group, alkoxysilyl group (—Si (Oalkyl) ₃ ), aryloxysilyl 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), alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )) , Monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group, monoarylphosphono 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 ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) ( aryl)), monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group, monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group, cyano group, nitro group, group, ₍₂ -B (alkyl)) dialkyl boryl group, Jiariruboriru group (-B (aryl) _2), alkyl aryl boryl -B (alkyl) (aryl)) , dihydroxy boryl group (-B (OH) ₂₎ and its conjugated base group, an alkyl hydroxy boryl group (-B (alkyl) (OH) ) and its conjugated base group, an aryl hydroxy boryl And the group (—B (aryl) (OH)) and its conjugate base group, aryl group, alkenyl group and alkynyl group.

  For example, when the polymerizable composition of the present invention is used as a recording layer of a lithographic printing plate precursor, depending on the design of the recording layer, a substituent having a hydrogen atom capable of hydrogen bonding, particularly an acid rather than a carboxylic acid. Substituents having an acidity with a small dissociation constant (pKa) are not preferred because they tend to lower the printing durability. On the other hand, hydrophobic substituents such as halogen atoms, hydrocarbon groups (alkyl groups, aryl groups, alkenyl groups, alkynyl groups), alkoxy groups, aryloxy groups and the like are more preferable because they tend to improve printing durability. When the cyclic structure is a monocyclic aliphatic hydrocarbon having 6 or less members 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.

R ⁸ in the case where A in the general formula (i) is —NR ⁸ — 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 ⁸ include an alkyl group, an aryl group, an alkenyl group, and an alkynyl group.
Specific examples of the alkyl group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, isobutyl, sec-butyl, 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 a furyl group, a thienyl group, a pyrrolyl group, a pyridyl group, and a quinolyl group.
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 ⁸ may have is the same as those exemplified as the substituent that R ⁷ can introduce. The number of carbon atoms of R ⁸ is 1 to 10 including the carbon number of the substituent.

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

  Although the preferable specific example of the structural unit represented by general formula (i) which comprises the binder polymer especially suitable for this invention below is shown, it is not limited to these.

  The structural unit represented by the general formula (i) may have only one type in the binder polymer, or may have two or more different types. That is, the preferred binder polymer in the present invention may be a polymer composed only of the structural unit represented by the general formula (i), but is generally used as a copolymer combined with other copolymerization components. Is. The total content of the structural unit represented by the general formula (i) in the copolymer is appropriately determined depending on the structure, the design of the polymerizable composition, and the like, but preferably 1 to 99 with respect to the total molar amount of the polymer component. It is contained in the range of mol%, more preferably 5 to 40 mol%, still more preferably 5 to 20 mol%.

  As a copolymerization component in the case of using as a copolymer, a conventionally well-known thing can be used without a restriction | limiting, if it is a monomer which can be radically polymerized. Specific examples include monomers described in “Polymer Data Handbook—Basic Edition” (Edition of Polymer Society, Bafukan, 1986). One type of such copolymerization component may be used, or two or more types may be used in combination.

Among the above binder polymers, in particular, [allyl (meth) acrylate / (meth) acrylic acid / other addition polymerizable vinyl monomer as required] copolymer, JP-A Nos. 2000-131837 and 2002-62648. A polymer containing an acrylic group, a methacryl group or an allyl group as described in JP 2000-187322 A or Japanese Patent Application No. 2002-287920 has a balance of film strength, sensitivity, and developability. It is excellent and suitable.
Among them, a polymer having a structural unit represented by the general formula (i) and a radical polymerizable group (carbon-carbon double bond) having a structure represented by the following general formulas (ii) to (iv) Is most preferred.

In general formulas (ii) to (iv), R ^{21 to} R ⁴² each independently represents a hydrogen atom or a monovalent substituent. X and Y each independently represent an oxygen atom, a sulfur atom, or N—R ²⁴ , and Z represents an oxygen atom, a sulfur atom, —N—R ^24, or a phenylene group. Here, R ²⁴ represents a hydrogen atom or a monovalent organic group.

In the general formula (ii), R ^{21 to} R ²³ each independently represents a hydrogen atom or a monovalent substituent, and R ²¹ may be a hydrogen atom or an alkyl which may have a substituent. An organic group such as a group is mentioned, and specifically, a hydrogen atom, a methyl group, a methylalkoxy group, and a methyl ester group are preferable. R ²² and R ²³ may each independently have a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or a substituent. Alkyl group, aryl group which may have a substituent, alkoxy group which may have a substituent, aryloxy group which may have a substituent, alkylamino group which may have a substituent, substituted An arylamino group that may have a group, an alkylsulfonyl group that may have a substituent, an arylsulfonyl group that may have a substituent, and the like, among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable.
Here, examples of the substituent that can be introduced into these groups include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group, a methyl group, an ethyl group, and a phenyl group.
X represents an oxygen atom, a sulfur atom, or —N—R ²⁴ , where R ²⁴ includes an alkyl group that may have a substituent.

In the general formula (iii), R ^{31 to} R ³⁵ each independently represents a hydrogen atom or a monovalent substituent, and R ^{31 to} R ³⁵ are, for example, a hydrogen atom, a halogen atom, an amino group, Dialkylamino group, carboxyl group, alkoxycarbonyl group, sulfo group, nitro group, cyano group, optionally substituted alkyl group, optionally substituted aryl group, optionally substituted An alkoxy group, an optionally substituted aryloxy group, an optionally substituted alkylamino group, an optionally substituted arylamino group, an optionally substituted alkylsulfonyl group An arylsulfonyl group which may have a substituent, etc., among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group which may have a substituent, an aryl which may have a substituent. Group is preferred.
Here, as a substituent which can be introduced into these groups, those exemplified as the substituent which can be introduced in the general formula (ii) are exemplified.
Y represents an oxygen atom, a sulfur atom, or —N—R ²⁴ . Examples of R ²⁴ include the same as those in general formula (ii).

In the general formula (iv), R ^{41 to} R ⁴³ each independently represents a hydrogen atom or a monovalent substituent. Specific examples thereof include a hydrogen atom, a halogen atom, an amino group, and a dialkylamino group. A carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, Aryloxy group which may have a substituent, alkylamino group which may have a substituent, arylamino group which may have a substituent, alkylsulfonyl group which may have a substituent, substituent An arylsulfonyl group that may have a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group that may have a substituent, and an aryl group that may have a substituent. Masui.
Here, as the substituent that can be introduced into these groups, examples of the substituent that can be introduced into these groups include those exemplified as the substituent that can be introduced in the general formula (ii).
Z represents an oxygen atom, a sulfur atom, —N—R ²⁴ or a phenylene group. Examples of R ²⁴ include the same as those in general formula (ii).

  Among these radical polymerizable groups, a radical polymerizable group having a structure represented by the general formulas (ii) and (iii) is preferable.

Other binder polymers include JP-B Nos. 7-12004, 7-120041, 7-120042, 8-12424, JP-A 63-287944, and JP-A 63-287947. No. 1, Japanese Patent Application Laid-Open No. 1-271741, Japanese Patent Application No. 10-116232, etc., the urethane-based binder polymer containing an acid group is very excellent in strength. It is advantageous in terms of aptitude.
Further, the binder polymer having an amide group described in JP-A-11-171907 has excellent developability and film strength, and this binder polymer can also be applied to the present invention.

In addition, polyvinyl pyrrolidone, polyethylene oxide, and the like are useful as the water-soluble linear organic polymer. In addition, in order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful.
These linear organic high molecular polymers can be mixed in an arbitrary amount in the total polymerizable composition. However, when the blending amount exceeds 90% by mass, a preferable result is not given in terms of the image strength to be formed. Preferably it is 30-85 mass%. Moreover, it is preferable that (C) polymeric compound and linear organic high molecular polymer mentioned above shall be the range of 1 / 9-7 / 3 by mass ratio.
Each of these binder polymers may be used alone or in combination of two or more.

  The molecular weight of the (D) binder polymer in the present invention is appropriately determined from the viewpoints of image formability and printing durability, but usually the preferred molecular weight is 2,000 to 1,000,000, more preferably 5, The range is from 000 to 500,000, more preferably from 10,000 to 200,000.

  As the binder polymer (D) in the present invention, a binder polymer that is substantially insoluble in water and soluble in an alkaline aqueous solution is used. For this reason, the organic solvent which is not environmentally preferable is not used as a developing solution, or it can restrict | limit to the very small usage-amount. The acid value of the (D) binder polymer (the acid content per gram of polymer expressed as a chemical equivalent number) and the molecular weight are appropriately selected from the viewpoint of image strength and developability. The preferred acid value is 0.4 to 3.0 meq / g, the preferred molecular weight is in the range of 2000 to 500,000, more preferably the acid value is 0.6 to 2.0, and the molecular weight is 10,000 to 300,000. Range.

In addition to the essential components (A) to (D), various compounds can be used in combination with the polymerizable composition of the present invention as long as the effects of the present invention are not impaired. Hereinafter, preferable additive components will be described.
[(E) monocarboxylic acid compound]
A compound represented by the following general formula (v) (hereinafter, referred to as “monocarboxylic acid compound” as appropriate) can be added to the polymerizable composition of the present invention. By adding such a compound to the polymerizable compound, the decomposition rate of the radical polymerization initiator can be improved, and further, the generated polymerization initiation radical or polymerization growth radical can undergo radical chain transfer to the monocarboxylic acid compound. It is considered that the polymerization reaction of the polymerizable compound is accelerated. Further, by adding such a compound, there is an effect that the storage stability of the radical polymerization type light-sensitive material, which was originally insufficient, is improved.

In general formula (v), A represents an aromatic group or a heterocyclic group. R ⁵¹ and R ⁵² each independently represents a hydrogen atom or a monovalent substituent. R ⁵¹ and R ⁵² , R ⁵¹ and R ⁵² and X, R ⁵¹ and R ⁵² and A, A and X may be bonded to each other to form a ring structure. X represents —O—, —S—, —SO ₂ —, —NH—, —N (R ⁵³ ) —, —CH ₂ —, —CH (R ⁵⁴ ) — and —C (R ⁵⁴ ) (R ⁵⁵ ) ^. )-Represents a divalent linking group selected from-, R ⁵³ , R ⁵⁴ or R ⁵⁵ each independently represents a hydrogen atom or a monovalent substituent.

Here, in the general formula (v), the aromatic group represented by A includes a benzene ring, two to three benzene rings forming a condensed ring, a benzene ring and a 5-membered unsaturated ring condensed. Examples include those that form a ring. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable.
In addition, the aromatic group may have a substituent, and as the aromatic group having such a substituent, a monovalent other than a hydrogen atom is used as a substituent on a ring-forming carbon atom of an aryl group described later. And those having a group consisting of a nonmetallic atomic group. As the preferred examples of the substituent to be introduced, wherein the alkyl groups mentioned in the description of R ¹ to R ⁵ in the general formula (2) to (4), substituted alkyl groups, and substituted in the substituted alkyl group What was shown as a group can be mentioned.

As the heterocyclic group represented by A, a pyrrole ring group, a furan ring group, a thiophene ring group, a benzopyrrole ring group, a benzofuran ring group, a benzothiophene ring group, a pyrazole ring group, an isoxazole ring group, an isothiazole ring group, Indazole ring group, benzisoxazole ring group, benzoisothiazole ring group, imidazole ring group, oxazole ring group, thiazole ring group, benzimidazole ring group, benzoxazole ring group, benzothiazole ring group, pyridine ring group, quinoline ring Group, isoquinoline ring group, pyridazine ring group, pyrimidine ring group, pyrazine ring group, phthalazine ring group, quinazoline ring group, quinoxaline ring group, acylidene ring group, phenanthridine ring group, carbazole ring group, purine ring group, pyran ring Group, piperidine ring group, piperazine ring group, morpholine ring group, indole ring group, Ndorijin ring group, a chromene ring group, a cinnoline ring group, an acridine ring group, a phenothiazine ring group, a tetrazole ring group, a triazine ring group, and the like.
Moreover, the heterocyclic group may have a substituent, and as such a substituent, the aryl group described in the description of R ^{1 to} R ^{5 in} the general formulas (2) to (4) is used. Substituents introduced on ring-forming carbon atoms are used. Preferred examples of the substituent include the alkyl groups, substituted alkyl groups, and those shown as substituents in the substituted alkyl group.

Next, in the general formula (v), as the monovalent substituent represented by R ⁵¹ and R ⁵² , a halogen atom, an amino group which may have a substituent, an alkoxycarbonyl group, a hydroxyl group, an ether group, Examples include a thiol group, a thioether group, a silyl group, a nitro group, and a cyano group, and an alkyl group, an alkenyl group, an alkynyl group, an aryl group, and a heterocyclic group, each of which may have a substituent.

  Examples of such an alkyl group include linear, branched, and cyclic alkyl groups having 1 to 20 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. Group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t Examples include -butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group, and 2-norbornyl group. Of these, linear alkyl groups having 1 to 12 carbon atoms, branched alkyl groups having 3 to 12 carbon atoms, and cyclic alkyl groups having 5 to 10 carbon atoms are more preferable.

As the substituent that such an alkyl group can have, a group composed of a monovalent nonmetallic atomic group excluding a hydrogen atom is used, and preferred examples include R ^{1 in the} general formulas (2) to (4). those mentioned in the substituent group constituted by non-metal atoms monovalent mentioned in the description of to R ⁵ are mentioned as well.

Next, X in the general formula (v) will be described. X represents —O—, —S—, —SO ₂ —, —NH—, —N (R ⁵³ ) —, —CH ₂ —, —CH (R ⁵⁴ ) — and —C (R ⁵⁴ ) (R ⁵⁵ ) ^. )-Represents a divalent linking group selected from: —NH—, —N (R ⁵³ ) —, —CH ₂ —, —CH (R ⁵⁴ ) —, —C (R ⁵⁴ ) (R ⁵⁵ ) )-Is preferable from the viewpoint of sensitivity, more preferably -NH-, -N (R ³ )-, and most preferably -N (R ⁵³ )-from the viewpoint of sensitivity and storage stability.

Here, R ⁵³ , R ⁵⁴ and R ⁵⁵ in X each independently represent a hydrogen atom or a monovalent substituent. Examples of such a monovalent substituent include R ⁷ in the general formula (i). , R ⁸ is synonymous.
In particular, R ⁵³ is preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, each of which may have a substituent. R ⁵³ preferably has at least one of —CO ₂ — and —CON (R ⁵⁹ ) — in its structure, and the most preferable structure of R ⁵⁹ is represented by the following formula. Is.

In the above formula, R ⁵⁶ , R ⁵⁷ and R ⁵⁸ each independently represent a hydrogen atom or a monovalent substituent, and Z represents a monovalent substituent. Such a monovalent substituent has the same meaning as R ⁷ or R ⁸ in formula (i).

Further, the monovalent substituent represented by R ⁵⁴ and R ⁵⁵ in X is the same as R ⁷ or R ⁸ in the general formula (i).

  Specific examples (A-1) to (A-87) of the monocarboxylic acid compound represented by the general formula (v) are listed below, but the present invention is not limited thereto.

The (E) monocarboxylic acid compound that can be used in the present invention can be synthesized, for example, by the method described in Japanese Patent Application No. 2003-31254 filed earlier by the applicant of the present application.
The monocarboxylic acid compound according to the present invention may be used alone or in combination of two or more. The addition amount of these monocarboxylic acids is 0.1 to 70% by mass, preferably 0.5 to 50% by mass, more preferably 1 to 30% by mass in the total solid content of the polymerizable composition. can do. When the addition amount is within this range, the effect of improving the sensitivity of the polymerizable composition of the present invention can be obtained, and when this polymerizable composition is used as a recording material for a lithographic printing plate precursor, the occurrence of stains in the non-image area Is suppressed, and excellent film properties can be obtained both before and after the recording layer is cured.

[(F) Other components]
In the polymerizable composition of the present invention, other components suitable for its use, production method and the like can be added as appropriate. In particular, additives that are suitable when the polymerizable composition of the present invention is used as a recording layer of a lithographic printing plate precursor will be described below.

(F-1) Co-sensitizer The sensitivity can be further improved by using a certain additive in the polymerizable composition. Such a compound is hereinafter referred to as a co-sensitizer. These mechanisms of action are not clear, but many are thought to be based on the following chemical processes. That is, a co-sensitizer reacts with various intermediate active species (radicals and cations) generated in the course of the photoreaction initiated by the polymerization initiator and the subsequent addition polymerization reaction to generate new active radicals. Estimated. These can be broadly divided into (i) those that can be reduced to produce active radicals, (ii) those that can be oxidized to produce active radicals, and (iii) radicals that are more active by reacting with less active radicals. Can be classified into those that act as chain transfer agents, but there is often no generality as to which of these individual compounds belong.

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

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

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

(Iii) Compounds that react with radicals to convert into highly active radicals or act as chain transfer agents: For example, a compound group having SH, PH, SiH, GeH in the molecule is used. These can donate hydrogen to low-activity radical species to generate radicals, or can be oxidized and then deprotonated to generate radicals. Specifically, 2-mercaptobenzimidazoles etc. are mentioned, for example.

More specific examples of these (F-1) co-sensitizers are described, for example, in JP-A-9-236913 as additives for the purpose of improving sensitivity. The present invention can also be applied.
These (F-1) cosensitizers can be used alone or in combination of two or more. The amount used is suitably in the range of 0.05 to 100 parts by weight, preferably 1 to 80 parts by weight, more preferably 3 to 50 parts by weight with respect to 100 parts by weight of the polymerizable compound (C).

(F-2) Polymerization inhibitor In the present invention, in order to prevent unnecessary thermal polymerization of the polymerizable compound (C) during the production or storage of the polymerizable composition constituting the recording layer, (F -2) It is desirable to add a small amount of a thermal polymerization inhibitor as a polymerization inhibitor. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol ), 2,2′-methylenebis (4-methyl-6-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. In addition, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition due to oxygen, and a lithographic printing plate precursor is dried after coating on a support or the like. In this process, it may be unevenly distributed on the surface of the recording layer. The amount of the higher fatty acid derivative added is preferably about 0.5% by mass to about 10% by mass of the total composition.

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

(F-4) Other additives The polymerizable composition of the present invention is described in the specification of Japanese Patent Application No. 2003-058410 filed earlier by the applicant of the present application for the purpose of further improving sensitivity, stability, and developability. It is preferable to add a compound having at least one carboxylic acid group and at least one amino group or thioether group in the molecule.

  Furthermore, the polymerizable composition of the present invention improves the ink depositing property on the surface of the recording layer when used as an inorganic filler for improving the physical properties of the cured film, as well as a plasticizer and a lithographic printing plate precursor. You may add well-known additives, such as a fat-sensitizing agent obtained.

  Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, and triacetyl glycerin, and a binder was used. In this case, 10% by mass or less can be added with respect to the total mass of the compound having an ethylenically unsaturated double bond and the binder.

Further, for the purpose of improving the film strength (printing durability), which will be described later, a UV initiator, a thermal crosslinking agent, or the like can be added to enhance the effect of heating and exposure after development.
In addition, when applied to the photosensitive layer of a lithographic printing plate precursor described later, it is possible to contain an additive for improving the adhesion between the photosensitive layer and the support and improving the development removability of the unexposed recording layer. . For example, by adding a compound having a relatively strong interaction with the support, such as a compound having a diazonium structure or a phosphone compound, or by undercoating them, it is possible to improve adhesion and improve printing durability. is there. Further, by adding a hydrophilic polymer such as polyacrylic acid or polysulfonic acid, or by undercoating them, the developability of the non-image area is improved, and the stain resistance can be improved.

  The polymerizable composition of the present invention obtained as described above is a polymerizable composition excellent in sensitivity and storage stability, and includes three-dimensional stereolithography, holography, lithographic printing plate precursor, color proof, photoresist and It can be used for image recording materials such as color filters, inks, paints, adhesives, and the like. In particular, it is suitably used as a photosensitive layer (recording layer) of a negative lithographic printing plate precursor as described in detail below. It is done.

[Lithographic printing plate precursor]
The lithographic printing plate precursor according to the present invention comprises a photosensitive layer (recording layer) comprising the polymerizable composition according to the present invention on a support, and in addition to the photosensitive layer, if necessary, Arbitrary layers having various characteristics such as a back coat layer, an intermediate layer, and a protective layer can also be provided.
Hereinafter, although the lithographic printing plate precursor according to the invention will be described in detail, the application of the polymerizable composition according to the invention is not limited to the following embodiments.

  When the polymerizable composition of the present invention is used as a photosensitive layer of a lithographic printing plate precursor, it can be produced by dissolving the polymerizable composition in a solvent and coating it on a suitable support. Depending on the purpose, various additives, backcoat layers, intermediate layers, protective layers and the like described later can be formed in the same manner.

  Solvents used in the photosensitive coating solution include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl Acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, toluene, water, etc. However, it is not limited to this. These solvents are used alone or in combination. The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by mass.

In addition, the coating amount (solid content) of the photosensitive layer on the support obtained after coating and drying varies depending on the use, but the lithographic printing plate precursor is generally 0.5% from the viewpoint of sensitivity and film properties. -5.0 g / m < ² > is preferable.
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

  The polymerizable composition of the present invention is preferably applied to the photosensitive layer of a lithographic printing plate precursor. In order to increase the processing stability of such a photosensitive layer with respect to development conditions, JP-A-62-251740 and Nonionic surfactants as described in JP-A-3-208514, amphoteric surfactants as described in JP-A-59-121044 and JP-A-4-13149, JP-A-62-2 Fluorosurfactants such as those described in 170950 can be added.

  Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like.

Specific examples of amphoteric surfactants include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl-N, N- Examples include betaine type (for example, trade name Amorgen K, manufactured by Dai-ichi Kogyo Co., Ltd.).
The proportion of each surfactant in the photosensitive layer coating solution is preferably 0.05 to 15% by mass, more preferably 0.1 to 5% by mass.

  Furthermore, in the photosensitive layer coating solution according to the present invention, a plasticizer is added as needed to impart flexibility of the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate and the like are used.

(Support)
The support used when forming a lithographic printing plate precursor using the polymerizable composition of the present invention is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, plastic ( For example, paper laminated with polyethylene, polypropylene, polystyrene, etc., metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate) Cellulose, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.). These may be a single component sheet such as a resin film or a metal plate, or may be a laminate of two or more materials. For example, a paper or plastic film on which a metal as described above is laminated or vapor-deposited. And laminated sheets of different plastic films.

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

Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired.
The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used.

  The aluminum plate roughened in this way can be subjected to an anodizing treatment to enhance the water retention and wear resistance of the surface through an alkali etching treatment and a neutralization treatment, if desired. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.

The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. However, in general, the electrolyte concentration is 1 to 80% by mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. dm ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are suitable.
The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodic oxide coating is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image part of the lithographic printing plate is easily scratched, so that the ink adheres to the scratched part during printing. “Scratches and dirt” are likely to occur.
Such anodizing treatment is applied to the surface used for printing the support of the lithographic printing plate, but an anodized film of 0.01 to 3 g / m ² is also formed on the back surface due to the back of the lines of electric force. It is common to form.

The hydrophilic treatment of the support surface is performed after the anodizing treatment, and conventionally known treatment methods are used. Such hydrophilization treatment is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are various alkali metal silicate methods (for example, sodium silicate aqueous solution). In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, it is disclosed in potassium fluoride zirconate disclosed in Japanese Patent Publication No. 36-22063 and US Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid as described above is used.
Among these, a particularly preferred hydrophilic treatment in the present invention is a silicate treatment. The silicate treatment will be described below.

The anodized film of the aluminum plate subjected to the treatment as described above has an alkali metal silicate content of 0.1 to 30% by mass, preferably 0.5 to 10% by mass, and a pH at 25 ° C. of 10 to 13. It is immersed in a certain aqueous solution at, for example, 15 to 80 ° C. for 0.5 to 120 seconds. If the pH of the alkali metal silicate aqueous solution is lower than 10, the solution will gel, and if it is higher than 13.0, the oxide film will be dissolved. Examples of the alkali metal silicate used in the present invention include sodium silicate, potassium silicate, and lithium silicate. Examples of the hydroxide used to increase the pH of the alkali metal silicate aqueous solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, you may mix | blend alkaline-earth metal salt or Group IVB metal salt with said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Can be mentioned. Examples of Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, potassium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, etc. Can do. Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. A preferable range of these metal salts is 0.01 to 10% by mass, and a more preferable range is 0.05 to 5.0% by mass.
Since the hydrophilicity on the surface of the aluminum plate is further improved by the silicate treatment, the ink hardly adheres to the non-image area during printing, and the stain performance is improved.

(Back coat layer)
A back coat is provided on the back surface of the support as necessary. As such a backcoat, a coating comprising a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 A layer is preferably used.
Among these coating layers, silicon alkoxy compounds such as SI (OCH ₃ ) ₄ , SI (OC ₂ H ₅ ) ₄ , SI (OC ₃ H ₇ ) ₄ , SI (OC ₄ H ₉ ) ₄ are available at low cost. The coating layer of the metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

(Middle layer)
In the lithographic printing plate precursor according to the invention, an intermediate layer may be provided for the purpose of improving the adhesion and soiling between the photosensitive layer and the support. Specific examples of such an intermediate layer include JP-B-50-7481, JP-A-54-72104, JP-A-59-101651, JP-A-60-149491, JP-A-60-232998, JP-A-3-56177, JP-A-4-282737, JP-A-5-16558, JP-A-5-246171, JP-A-7-159983, JP-A-7-314937, JP-A-8-202025, Special Kaihei 8-320551, JP 9-34104, JP 9-236911, JP 9-269593, JP 10-69092, JP 10-115931, JP 10-161317, JP 10-260536, JP-A-10-282682, JP-A-11-84684, Japanese Patent Application No. 8-225335, Japanese Patent Application No. 8-270098, Japanese Patent Application No. 9-195863, Japanese Patent Application No. 9-195864, Japanese Patent Application No. 9-89646, Japanese Patent Application No. 9-106068, Japanese Patent Application No. 9-183834, Japanese Patent Application No. 9-264411, Japanese Patent Application No. 9 -127232, Japanese Patent Application No. 9-245419, Japanese Patent Application No. 10-127602, Japanese Patent Application No. 10-170202, Japanese Patent Application No. 11-36377, Japanese Patent Application No. 11-165661, Japanese Patent Application No. 11-284091 No., Japanese Patent Application No. 2000-14697, and the like.

(Protective layer)
Since the lithographic printing plate precursor in which the polymerizable composition of the present invention is applied to the photosensitive layer is usually exposed in the air, a protective layer (also referred to as an overcoat layer) may be further provided on the photosensitive layer. preferable.
The protective layer prevents exposure of low molecular weight compounds such as oxygen and basic substances present in the atmosphere that hinder the image formation reaction caused by exposure in the photosensitive layer to allow exposure in the atmosphere. To do. Therefore, the properties desired for such a protective layer are low permeability of low-molecular compounds such as oxygen, and further, transmission of light used for exposure is not substantially inhibited, and adhesion to the photosensitive layer is excellent. And it is desirable that it can be easily removed in the development process after exposure. Such a device relating to the protective layer has been conventionally devised and is described in detail in US Pat. No. 3,458,311 and Japanese Patent Publication No. 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 the 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. 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, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA- 420, PVA-613, L-8 and the like.

  Components of the protective layer (selection of PVA, use of additives), coating amount, and the like are selected in consideration of fogging, adhesion, and scratch resistance in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of the PVA used (the higher the content of the unsubstituted vinyl alcohol unit in the protective layer), the thicker the film thickness, the higher the oxygen barrier property, which is advantageous in terms of sensitivity. 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 an oleophilic photosensitive layer, film peeling due to insufficient adhesive force is likely 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, U.S. Patent Application No. 292,501 and U.S. Patent Application No. 44,563 disclose an acrylic emulsion or a water-insoluble vinylpyrrolidone-vinyl acetate copolymer in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and the like and laminating on the photosensitive layer.

Any of these known techniques can be applied to the protective layer in the present invention. Such a coating method of the protective layer is described in detail in, for example, US Pat. No. 3,458,311 and JP-B-55-49729.
Therefore, in the present invention, it is preferable to use polyvinyl alcohol and polyvinyl pyrrolidone in combination from the viewpoints of adhesive strength, sensitivity, and unnecessary fog. The addition ratio (mass ratio) is preferably 3/1 or less of polyvinyl alcohol / polyvinylpyrrolidone.

Another preferred embodiment of the protective layer according to the present invention is a protective layer formed by adding a mica compound. That is, by adding at least one polyvinyl alcohol selected from the group consisting of a mica compound and a polyvinyl alcohol having a saponification degree of 90 mol% or less and an acid-modified polyvinyl alcohol to the protective layer, excellent development removability and film Strength can be achieved, and further, matting properties can be imparted to the protective layer. As a result, the protective layer can be prevented from being deteriorated due to deformation or the like in addition to the above-described barrier property against oxygen or the like, and can be removed in the developing step even if the pre-water washing step is omitted. Further, since the matte property is imparted to the protective layer, when the planographic printing plate precursor of the present invention is laminated, the planographic printing plate precursor adjacent to the photosensitive layer side surface (protective layer surface) of the planographic printing plate precursor It also has the advantage that it becomes possible to suppress adhesion to the support side surface.
Hereinafter, the mica compound and specific polyvinyl alcohol used in such a protective layer will be described.

(Mica compound)
The mica compound used in the present invention is, for example, the general formula A (B, C) ₂ -5D ₄ O ₁₀ (OH, F, O) ₂ [where A is any of K, Na, Ca, B And C is any one of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. And mica groups such as natural mica and synthetic mica.

In the mica group, examples of natural mica include muscovite, soda mica, phlogopite, biotite, and mica. Synthetic mica includes non-swelling mica such as fluorine phlogopite mica ₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicon mica KMg _2.5 (Si ₄ O ₁₀ ) F ₂ , and Na tetrasilicic mica NaMg _2.5. (Si ₄ O ₁₀ ) F ₂ , Na or Li teniolite (Na, Li) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , montmorillonite-based Na or Li hectorite (Na, Li) _1/8 Mg _2/5 Examples thereof include swelling mica such as Li _1/8 (Si ₄ O ₁₀ ) F ₂ . Synthetic smectite is also useful.

In the present invention, among the mica compounds, fluorine-based swellable mica is particularly useful. That is, this swellable synthetic mica has a laminated structure composed of unit crystal lattice layers with a thickness of about 10 to 15 mm, and the substitution of metal atoms in the lattice is significantly larger than other viscosity minerals. As a result, the lattice layer is deficient in positive charges, and cations such as Na ⁺ , Ca ²⁺ and Mg ²⁺ are adsorbed between the layers in order to compensate for this. The cations present between these layers are called exchangeable cations and exchange with various cations. In particular, when the cation between the layers is Li ⁺ or Na ⁺ , since the ionic radius is small, the bond between the layered crystal lattices is weak, and the layer swells greatly with water. If shear is applied in this state, it will be easily cleaved to form a stable sol in water. Swellable synthetic mica has a strong tendency and is useful in the present invention. In particular, swellable synthetic mica is preferably used.

  The shape of the mica compound used in the present invention is preferably as thin as possible from the viewpoint of diffusion control, and the plane size is large as long as the smoothness of the coated surface and the transmittance of actinic rays are not hindered. Moderate. Accordingly, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured from, for example, a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  The average diameter of the mica compound used in the present invention is 0.3 to 20 μm, preferably 0.5 to 10 μm, particularly preferably 1 to 5 μm. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. Specifically, for example, the swellable synthetic mica that is a representative compound has a thickness of 1 to 50 nm and a surface size (major axis) of about 1 to 20 μm.

  The amount of the mica compound contained in the protective layer is preferably in the range of 5 to 55% by mass with respect to the total solid content of the protective layer, from the viewpoint of the balance between adhesion resistance and film formation. More preferably, it is the range of 10-40 mass%.

(Polyvinyl alcohol and acid-modified polyvinyl alcohol having a saponification degree of 90 mol% or less)
As in the present invention, the basic characteristic desired for the protective layer provided on the polymerizable negative photosensitive layer is that the low-molecular compound such as oxygen has low permeability, and the transmission of light used for exposure is low. It does not substantially impede, is excellent in adhesion to the photosensitive layer, and can be easily removed in the development step after exposure.
In order to obtain better development removability in addition to the basic properties desired for such a protective layer, in the present invention, as a binder component of the protective layer, polyvinyl alcohol and acid having a saponification degree of 90 mol% or less are used. At least one polyvinyl alcohol selected from the group consisting of modified polyvinyl alcohol is used.
These specific polyvinyl alcohols all have excellent film-forming properties and further have high solubility in a developer.

-Polyvinyl alcohol having a saponification degree of 90 mol% or less-
The polyvinyl alcohol having a saponification degree of 90 mol% or less used in the present invention is partially ester, ether and acetal as long as it contains an unsubstituted vinyl alcohol unit for having the necessary oxygen barrier properties and water solubility. May be substituted. Similarly, some of them may have other copolymer components.
In general, the lower the degree of saponification of the PVA used (the lower the content of the unsubstituted vinyl alcohol unit in the protective layer), the lower the oxygen barrier property, which is disadvantageous in terms of sensitivity. Has improved properties. On the other hand, the protective layer according to the present invention improves the film strength of the protective layer by using polyvinyl alcohol having a saponification degree of 90 mol% or less and the mica compound in combination, thereby reducing the oxygen barrier property. Can be suppressed. As a result, both high sensitivity and development removability can be achieved.

  Such a polyvinyl alcohol having a saponification degree of 90 mol% or less preferably has a molecular weight in the range of 300 to 2400. Specifically, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-224, PVA-217EE, PVA-217E, PVA-220E, manufactured by Kuraray Co., Ltd. PVA-224E, PVA-405, PVA-420, PVA-613, L-8, etc. are mentioned.

-Acid-modified polyvinyl alcohol-
Specific examples of the acid-modified polyvinyl alcohol used in the present invention include itaconic acid, maleic acid-modified carboxy-modified polyvinyl alcohol, and sulfonic acid-modified polyvinyl alcohol. Examples of such acid-modified polyvinyl alcohol include KL-504, KL-506, KL-318, KL-118, KM-618, KM-118, and SK-5102 manufactured by Kuraray Co., Ltd.

The components of the protective layer (selection of PVA and mica compound, 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 specific polyvinyl alcohol is preferably contained in the range of 45 to 95% by mass, and in the range of 60 to 90% by mass, based on the total solid content in the protective layer. Is more preferable. If it is less than 45% by mass, the film forming property is insufficient and the sensitivity is lowered, and if it exceeds 95% by mass, the effect on the adhesion resistance is hardly exhibited.
At least one kind of the specific polyvinyl alcohol may be used, and a plurality of kinds may be used in combination. Even when a plurality of kinds of specific polyvinyl alcohols are used in combination, the total amount is preferably in the above mass range.

Even when the above-described embodiment containing the specific polyvinyl alcohol and the mica compound is used as the protective layer in the present invention, any of the above-described known techniques can be applied to this embodiment as long as these effects are not impaired. it can.
When a large amount (for example, about 3000 to 5000 m ² ) of a printing plate is stored under high humidity and then continuously developed, waste that is estimated to be derived from the protective layer component and the onium salt that is the initiator is generated. However, when the specific initiator of the present invention and the specific protective layer containing the mica compound are used in combination, the occurrence of development residue is effectively suppressed and the stain in the developer tank is improved. It is what you have.

  The protective layer according to the present invention has excellent transparency of light used for exposing the photosensitive layer (infrared light in the present invention) and can efficiently absorb light having a wavelength not related to exposure. An agent (water-soluble dye) may be added. Thereby, safelight aptitude can be improved, without reducing a sensitivity.

(Formation of protective layer)
The protective layer in the present invention is formed by dissolving the binder component described above in an appropriate solvent and applying it to the photosensitive layer, but when using a mica compound, prepare a dispersion in which the mica compound is dispersed, Applying a protective layer coating solution on the photosensitive layer by blending the dispersion and the binder component containing the specific polyvinyl alcohol (or an aqueous solution in which the binder component containing the specific polyvinyl alcohol is dissolved). Formed with.

First, an example of a general dispersion method of the mica compound used for the protective layer will be described. First, 5 to 10 parts by mass of the swellable mica compound mentioned above as a preferable mica compound is added to 100 parts by mass of water, and the mixture is thoroughly swelled and swollen, and then dispersed by a disperser. Examples of the disperser used here include various mills that disperse mechanically by applying a direct force, a high-speed stirring disperser having a large shearing force, and a disperser that provides high-intensity ultrasonic energy. Specifically, ball mill, sand grinder mill, visco mill, colloid mill, homogenizer, tisol bar, polytron, homomixer, homo blender, ketdy mill, jet agitator, capillary emulsifier, liquid siren, electrostrictive ultrasonic generator, An emulsifying device having a Paulman whistle can be used. A dispersion of 2 to 15% by mass of the mica compound dispersed by the above method is highly viscous or gelled, and the storage stability is very good.
When preparing a coating solution for a protective layer using this dispersion, after diluting with water and stirring sufficiently, a binder component containing a specific polyvinyl alcohol (or an aqueous solution in which a binder component containing a specific polyvinyl alcohol is dissolved) It is preferable to blend and prepare.

  Known additives such as a surfactant for improving the coating property and a water-soluble plasticizer for improving the physical properties of the film can be added to the coating solution for the protective layer. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. A water-soluble (meth) acrylic polymer can also be added. Furthermore, known additives for improving the adhesion to the photosensitive layer and the temporal stability of the coating solution may be added to the coating solution.

  The method for coating the protective layer according to the present invention is not particularly limited, and a method described in US Pat. No. 3,458,311 or JP-A-55-49729 can be applied.

The coating amount of the protective layer, in general formula, the film strength, from the viewpoint of scratch resistance and optical transparency is preferably ^{1.0g / m 2 ~3.0g / m 2} . Further, in the embodiment using the mica compound, the coating amount is preferably ^{0.5g / m 2 ~2.0g / m 2} , even more preferably at 0.75g / m ² ~1.5g / m ² . When the coating amount of the protective layer is too large, there is a concern that light incident on the protective layer is scattered due to exposure at the time of image formation, thereby deteriorating image quality.

(Exposure, development and printing)
The lithographic printing plate precursor of the present invention in which the polymerizable composition of the present invention is applied to the photosensitive layer on the above-mentioned support surface can be recorded with an infrared laser. In the present invention, image exposure is preferably performed by a solid-state laser and a semiconductor laser that emit infrared rays having a wavelength of 760 nm to 1200 nm.

After exposure with an infrared laser, the lithographic printing plate precursor is preferably developed with water or an alkaline aqueous solution.
When an alkaline aqueous solution is used as the developer, a conventionally known alkaline aqueous solution can be used as the developer and replenisher for the polymerizable composition of the present invention. For example, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, Examples include inorganic alkali salts such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also used. These alkali agents are used alone or in combination of two or more.

  Further, when developing using an automatic developing machine, the developer in the developing tank for a long time is added to the developer by adding an aqueous solution (replenisher) that is the same as the developer or higher in alkali strength than the developer. It is known that a large amount of a lithographic printing plate precursor can be processed without replacing the plate. This replenishment method is also preferably applied in the present invention.

  Various surfactants, organic solvents, and the like can be added to the developer and the replenisher as necessary for the purpose of promoting and suppressing developability, dispersing development residue, and improving ink affinity of the printing plate image area. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Preferred organic solvents include benzyl alcohol. Moreover, addition of polyethylene glycol or a derivative thereof, or polypropylene glycol or a derivative thereof is also preferable. In addition, non-reducing sugars such as arabit, sorbit and mannitol can be added.

  Further, as necessary, the developer and replenisher may include hydroquinone, resorcin, sulfurous acid or sodium salt of potassium bisulfite, and other inorganic salt-based reducing agents, as well as organic carboxylic acids, antifoaming agents, and water softeners. It can also be added.

  The lithographic printing plate developed using the developer and replenisher described above is post-treated with a desensitizing solution containing rinsing solution containing a washing water, a surfactant and the like, gum arabic and starch derivatives. As the post-treatment when the polymerizable composition of the present invention is applied to the recording layer of the lithographic printing plate precursor, these treatments can be used in various combinations.

In recent years, automatic developing machines for printing plate materials have been widely used in the plate making and printing industries in order to rationalize and standardize plate making operations. This automatic developing machine is generally composed of a developing unit and a post-processing unit, and includes an apparatus for conveying a printing plate material, processing liquid tanks and a spray device. Each processing liquid pumped up is sprayed from a spray nozzle for development processing. In addition, recently, a method is also known in which a printing plate material is immersed and conveyed in a processing liquid tank filled with a processing liquid by a submerged guide roll or the like. In such automatic processing, each processing solution can be processed while being supplemented with a replenisher according to the processing amount, operating time, and the like. In addition, the electrical conductivity can be detected by a sensor and replenished automatically.
In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.

The lithographic printing plate obtained as described above can be subjected to a printing process after applying a desensitized gum if desired. However, if a lithographic printing plate having a higher printing durability is desired, a burning treatment is performed. Is given.
In the case of burning a lithographic printing plate, the preparation as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859 and JP-A-61-159655 is performed before burning. It is preferable to treat with a surface liquid.

As its method, with a sponge or absorbent cotton soaked with the surface-adjusting liquid, it is applied onto a lithographic printing plate, or a method in which the printing plate is immersed and applied in a vat filled with the surface-adjusting liquid, Application by an automatic coater is applied. Further, it is more preferable to make the coating amount uniform with a squeegee or a squeegee roller after coating.
In general, the amount of surface-adjusting solution applied is suitably 0.03 to 0.8 g / m ² (dry mass).
The lithographic printing plate coated with the surface-adjusting liquid is dried if necessary, and then heated to a high temperature with a burning processor (for example, burning processor BP-1300 sold by Fuji Photo Film Co., Ltd.). . In this case, the heating temperature and time are in the range of 180 to 300 ° C. and preferably in the range of 1 to 20 minutes, although depending on the type of components forming the image.

The burned lithographic printing plate can be subjected to conventional treatments such as washing and gumming as needed, but a surface-conditioning solution containing a water-soluble polymer compound or the like is used. In such a case, a so-called desensitizing treatment such as gumming can be omitted.
The lithographic printing plate obtained by such processing is applied to an offset printing machine or the like and used for printing a large number of sheets.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. In this example, the lithographic printing plate using the polymerizable composition of the present invention as a recording layer is evaluated, and the evaluation is regarded as the evaluation of the polymerizable composition of the present invention.

[Examples 1 to 11 and Comparative Examples 1 to 4 ]
(Production of support)
A molten metal of JIS A 1050 alloy containing 99.5% or more of aluminum and Fe 0.30%, SI 0.10%, TI 0.02%, and Cu 0.013% was subjected to cleaning treatment and cast. In the cleaning process, a degassing process was performed to remove unnecessary gases such as hydrogen in the molten metal, and a ceramic tube filter process was performed. The casting method was a DC casting method. The solidified 500 mm thick ingot was chamfered 10 mm from the surface and homogenized at 550 ° C. for 10 hours so as not to coarsen the intermetallic compound.
Next, after hot rolling at 400 ° C. and intermediate annealing at 500 ° C. for 60 seconds in a continuous annealing furnace, cold rolling was performed to obtain an aluminum rolled plate having a plate pressure of 0.30 mm. By controlling the roughness of the rolling roll, the centerline average surface roughness Ra after cold rolling was controlled to 0.2 μm. Then, it applied to the tension leveler in order to improve planarity.

Next, a surface treatment for making a lithographic printing plate support was performed.
First, in order to remove the rolling oil on the surface of the aluminum plate, degreasing treatment was carried out with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization and smut removal treatment were carried out with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds.
Next, in order to improve the adhesion between the support and the recording layer and to provide water retention to the non-image area, a so-called graining treatment was performed to roughen the surface of the support. While maintaining an aqueous solution containing 1% nitric acid and 0.5% aluminum nitrate at 45 ° C. and flowing an aluminum web through the aqueous solution, an alternating waveform with a current density of 20 A / dm ² and a duty ratio of 1: 1 by an indirect power supply cell Then, electrolytic graining was performed by giving an anode side electric quantity of 240 C / dm ² . Thereafter, etching treatment was performed with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization and smut removal treatment were performed with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds.

Furthermore, in order to improve wear resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. An anodized film of 2.5 g / m ² by using a 20% sulfuric acid aqueous solution as an electrolyte at 35 ° C. and carrying out an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power feeding cell while carrying an aluminum web into the electrolyte. Was made.

(Formation of photosensitive layer)
A photosensitive layer coating solution 1 having the following composition was prepared, applied to the aluminum support obtained as described above using a wire bar, and dried at 115 ° C. for 45 seconds in a hot air dryer to form a photosensitive layer. Formed. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² . Furthermore, the protective layer coating solution 1 having the following composition was applied using a slide hopper, and dried at 120 ° C. for 75 seconds with a hot air dryer to obtain a lithographic printing plate precursor according to the present invention. The coating amount of the protective layer was 2.3 g / m ² .

<Photosensitive layer coating solution 1>
-(A) Specific initiator or comparative initiator (compound described in Table 1) 0.35 g
(B) Compound having at least one ethylenically unsaturated bond capable of addition polymerization (compound described in Table 1) 2.0 g
-(C) Infrared absorber (compound described in Table 1) 0.08 g
-(D) Binder polymer (compound described in Table 1) 2.0 g
・ Fluorine-based surfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0.01 g
・ Methyl ethyl ketone 9.0g
・ Propylene glycol monomethyl ether 8.0g
・ Methanol 10.0g

<Protective layer coating solution 1>
-Polyvinyl alcohol (saponification degree 98.5 mol%, polymerization degree 500) 2.5g
・ Polyvinylpyrrolidone 0.5g
(K30, Tokyo Chemical Industry Co., Ltd. molecular weight 40,000)
・ Nonionic surfactant 0.05g
(EMAREX NP-10 manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 96.95g

Hereinafter, the specific initiator used in each example, which is a characteristic component of the present invention (A) is a specific initiator, compared initiator used in Comparative Example 1 to 4, specific to the present invention outside the scope of the radical polymerization initiator of the initiator. The structures of the radical polymerization initiators (H-1) and (H-2) used in the comparative examples are shown below.

The compounds (M-1) and (M-2) having at least one non-polymerizable ethylenically unsaturated bond used in Examples and Comparative Examples of the present invention are as follows (M- 1): NK Ester A-BPE-4 manufactured by Parent Nakamura Chemical Co., Ltd.
(M-2): Compound having the following structure

  Next, the structures of (C) infrared absorbers (IR-1) to (IR-3) shown in Examples and Comparative Examples are shown below.

  The structures of (D) binder polymers (B-1) to (B-3) used in Examples and Comparative Examples are shown below.

(exposure)
The obtained negative lithographic printing plate precursor is exposed with a Trendsetter 3244VFS manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser under the conditions of an output of 9 W, an outer drum rotation speed of 210 rpm, a plate surface energy of 100 mJ / cm ² , and a resolution of 2400 dpI. did.

(Development processing)
After the exposure, the film was developed using an automatic processor Stablon 900N manufactured by Fuji Photo Film Co., Ltd. As the developer, a 1: 4 water diluted solution of DV-2 manufactured by Fuji Photo Film Co., Ltd. was used for both the feed solution and the replenisher solution. The temperature of the developing bath was 30 ° C. As the finisher, a 1: 1 water dilution (pH = 10.8) of FN-6 manufactured by Fuji Photo Film Co., Ltd. was used.

[Evaluation of sensitivity]
The amount of energy required for recording was calculated based on the line width and laser output of the image obtained by the above exposure (with an infrared laser having a wavelength of about 830 to 850 nm) and development, the loss in the optical system, and the scanning speed. The smaller the value, the higher the sensitivity. The results are also shown in Table 1 below.

[Evaluation of storage stability]
The negative lithographic printing plate precursor before laser exposure was left under high temperature conditions (60 ° C.) for 3 days. After that, the negative lithographic printing plate precursor after storage is exposed to laser in the same manner as described above, the amount of energy required for recording is calculated, and the energy ratio before and after high humidity storage (energy after high temperature storage / energy before high temperature storage) Asked. This energy ratio of 1.1 or less is preferable for production, and it can be said that the storage stability is also good. The evaluation results are also shown in Table 1 below.

[Evaluation of printing durability]
The obtained lithographic printing plate was printed using a GEOS-G (N) ink manufactured by Dainippon Ink with a R201 printer manufactured by Roland. The printed matter in the solid image portion was visually observed, and the printing durability was evaluated by the number of sheets on which the image began to fade. The greater the number, the better the printing durability. The results are also shown in Table 1 below.

As apparent from Table 1, the planographic printing plates of Examples 1 to 11 to which (A) specific initiator according to the present invention was added were polymerization initiators (H-1) outside the range of the specific initiator according to the present invention. ) And (H-2) were found to be superior in sensitivity, storage stability and printing durability as compared to the lithographic printing plates of Comparative Examples 1 to 4 .

[Examples 12 to 25 , Comparative Examples 5 to 8]
(Formation of undercoat layer)
An undercoat liquid having the following composition was applied to the same aluminum support as in Example 1 with a wire bar, and dried at 90 ° C. for 30 seconds using a hot air dryer. The coating amount after drying was 10 mg / m ² .

<Undercoat liquid>
・ Β-Alanine 0.1g
・ Phenylphosphonic acid 0.1g
・ Methanol 40g
・ Pure water 60g

(Formation of photosensitive layer)
Next, the photosensitive layer coating solution 2 having the following composition was prepared, applied to the above-mentioned undercoated aluminum plate using a wire bar, and dried at 115 ° C. for 45 seconds with a hot air drying apparatus to form a photosensitive layer. did. The coating amount of the photosensitive layer after drying was in the range of 1.2 to 1.3 g / m ² . Further, the same protective layer layer coating solution 1 as in Example 1 was applied using a slide hopper, and dried at 120 ° C. for 75 seconds in a hot air dryer to obtain a lithographic printing plate precursor. The coating amount of the protective layer was 2.3 g / m ² .

<Photosensitive layer coating solution 2>
-(A) Specific initiator or comparative initiator (compound described in Table 2 ) 0.35 g
(B) Compound having at least one ethylenically unsaturated bond capable of addition polymerization (compound described in Table 2 ) 2.0 g
-(C) Infrared absorber (compound described in Table 2 ) 0.08 g
-(D) Binder polymer (compound described in Table 2 ) 2.0 g
・ Fluorine-based surfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0.01 g
・ Victoria Pure Blue Naphthalenesulfonic Acid 0.04g
・ Methyl ethyl ketone 9.0g
・ Propylene glycol monomethyl ether 8.0g
・ Methanol 10.0g

(Exposure and development processing)
The obtained negative planographic printing plate precursor was subjected to infrared laser exposure and development in the same manner as in Example 1 to obtain a planographic printing plate.

[Evaluation of sensitivity, storage stability and printing durability]
The obtained lithographic printing plate was evaluated in the same manner as in Example 1 for sensitivity, storage stability and printing durability. The results are shown in Table 2.

As is apparent from Table 2, the planographic printing plates of Examples 12 to 25 using the (A) specific initiator according to the present invention are polymerization initiators (H-1) outside the range of the specific initiator according to the present invention. ) And (H-2) were confirmed to be superior in sensitivity, oxygen dependence of sensitivity, storage stability, and printing durability compared to the lithographic printing plates of Comparative Examples 5-8.

[Examples 26 to 37 , Comparative Examples 9 to 12]
(Formation of undercoat layer)
A silicate treatment was performed on the same aluminum support as in Example 1 in order to ensure hydrophilicity as a non-image portion of the printing plate. The treatment was carried with a 1.5% aqueous solution of sodium silicate 3 maintained at 70 ° C. so that the contact time of the aluminum web was 15 seconds, and further washed with water. The adhesion amount of Si was 10 mg / m ² . Ra (center line surface roughness) of the support prepared as described above was 0.25 μm.

(Formation of photosensitive layer)
A photosensitive layer coating solution 3 having the following composition was coated on the undercoated aluminum support using a wire bar and dried at 115 ° C. for 45 seconds in a hot air drying apparatus to form a photosensitive layer. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² . Further, the same protective layer coating solution 1 as in Example 1 was applied using a slide hopper, and dried at 120 ° C. for 75 seconds with a hot air dryer to obtain a lithographic printing plate precursor. The coating amount of the protective layer was 2.3 g / m ² .

<Photosensitive layer coating solution 3>
-(A) Specific initiator or comparative initiator (compound described in Table 3 ) 0.35 g
(B) Compound having at least one ethylenically unsaturated bond capable of addition polymerization
(Compound described in Table 3 ) 2.0 g
-(C) Infrared absorber (compound described in Table 3 ) 0.08 g
-(D) Binder polymer (compound described in Table 3 ) 2.0 g
・ Fluorine-based surfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0.01 g
・ Victoria Pure Blue Naphthalenesulfonic Acid 0.04g
・ Methyl ethyl ketone 9.0g
1-methoxy-2-propanol 8.0g
・ Methanol 10.0g

(Exposure and development processing)
The obtained negative planographic printing plate precursor was subjected to infrared laser exposure and development in the same manner as in Example 1 to obtain a planographic printing plate.

[Evaluation of sensitivity, storage stability and printing durability]
The obtained lithographic printing plate was evaluated in the same manner as in Example 1 for sensitivity, storage stability and printing durability. The results are listed in Table 3.

As is apparent from Table 3, the planographic printing plates of Examples 26 to 37 using the (A) specific initiator according to the present invention are polymerization initiators (H-1) outside the range of the specific initiator according to the present invention. ) And (H-2) were confirmed to be highly sensitive and excellent in storage stability as compared with the planographic printing plates of Comparative Examples 9-12.

[Examples 38 to 46 ]
A photosensitive layer coating solution 4 was prepared in the same manner as in Example 1 except that the compounds used in the photosensitive layer coating solution 1 used in Example 1 were changed as shown in Table 4, and a wire bar was prepared on the aluminum plate. And dried at 115 ° C. for 45 seconds with a hot air dryer to form a photosensitive layer. The coating amount of the photosensitive layer after drying was in the range of 1.2 to 1.3 g / m ² . Further, a protective layer was formed as follows to obtain lithographic printing plate precursors of Examples 38 to 46 . The coating amount of the protective layer was 1.15 g / m ² as follows.

(Protective layer coating solution 2)
(1) Preparation of Mica Compound Dispersion 6.4 g of synthetic mica (“Somasif ME-100” manufactured by Corp Chemical Co., aspect ratio: 1000 or more) was added to 193.6 g of water, and the average particle size was measured using a homogenizer. : Dispersed until the diameter corresponding to a circle became 3 μm (laser scattering method) to obtain a mica dispersion.

(2) Application of protective layer coating solution 2 On the surface of the photosensitive layer described above, the obtained mica dispersion and a specific polyvinyl alcohol having a saponification degree of 90 mol% or less (PVA-203: saponification degree 88 mol%, Polymerization degree 300, manufactured by Kuraray Co., Ltd., a copolymer of polyvinylpyrrolidone and vinyl acetate (ICP, LUVITEC VA64W: polyvinylpyrrolidone / vinyl acetate = 6/4), and a surfactant (manufactured by Nippon Emulsion Co., Emalex) 710) and a mixed aqueous solution (coating solution for protective layer) were applied with a wire bar and dried at 125 ° C. for 75 seconds with a hot air dryer.
The content ratio of mica solid content / specific polyvinyl alcohol / copolymer of polyvinylpyrrolidone and vinyl acetate / surfactant in the mixed aqueous solution (protective layer coating solution 2) was 16/80/2/2 ( The total coating amount (the coating amount after drying) was 1.15 g / m ² .

(Comparative Examples 13 to 16)
In the photosensitive layer coating solution 1 used in Example 1, except that each compound was changed as shown in Table 4, a photosensitive layer coating solution was prepared in the same manner as in Example 1, and a wire bar was attached to the aluminum plate. And a photosensitive layer was formed by drying at 115 ° C. for 45 seconds using a hot air dryer. The coating amount of the photosensitive layer after drying was in the range of 1.2 to 1.3 g / m ² . Furthermore, the examples mixed aqueous solution used in 38 (protective layer coating solution 2) in the same manner as in Example 38 to form a protective layer was used to obtain a lithographic printing plate precursor of Comparative Example 13 to 16.

(Exposure and development processing)
Exposure was performed in the same manner as in Example 1, and after the exposure, heat treatment and washing with water were not performed, and development processing was performed at a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The developer used was a 1: 4 water diluted solution of DH-N, and the finisher used was a 1: 1 water diluted solution of GN-2K manufactured by FUJIFILM Corporation.

[Evaluation of sensitivity, storage stability and printing durability]
The obtained lithographic printing plates of Examples 38 to 46 and Comparative Examples 13 to 16 were evaluated in the same manner as in Example 1 for sensitivity, storage stability and printing durability. The results are shown in Table 4.

(Dirt of developer tank)
Further, in this example, the stain on the developer tank was evaluated.
The obtained lithographic printing plate precursor is left under high temperature conditions (60 ° C.) for 3 days, and then the stored negative lithographic printing plate precursor is exposed in the same manner as the exposure conditions described above, and the developer 45L After developing the amount corresponding to 5000 m ² , the developer was discharged, and the dirt in the developer tank was visually observed and evaluated as follows.
○ Dirt × No stain Table 4 shows the above results.

As is apparent from Table 4, the planographic printing plates of Examples 38 to 46 using the (A) specific initiator according to the present invention are polymerization initiators (H-1) outside the range of the specific initiator according to the present invention. ) And (H-2) were confirmed to be highly sensitive and excellent in storage stability as compared with the lithographic printing plates of Comparative Examples 13 to 16. Furthermore, it was found that even if the pre-water washing step was omitted and continuous development processing was performed, the inside of the developer tank was not soiled. On the other hand, the lithographic printing plate precursors of Comparative Examples 13 to 16 having a photosensitive layer not containing (A) a specific initiator have high humidity even if they have a protective layer containing a mica compound and a specific polyvinyl alcohol. It was found that when a large amount of continuous development processing was performed with the pre-water washing step omitted, dirt was seen in the developer tank and there was a problem in practical use.

Claims (6)

(A) a photopolymerization initiator having a structure represented by the following general formula ( 2 ), (B) a compound having at least one addition-polymerizable ethylenically unsaturated bond, (C) an infrared absorber, and (D) a binder A polymerizable composition containing a polymer.

In the general formula (2), M ⁺ represents an onium cation, and X represents —NR ³ — or —S—. R ^{1 to} R ³ each independently represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. A ² represents a monovalent substituent composed of a nonmetallic atom , and at least one of A ² , R ¹ , R ² , and R ³ has one or more carboxylic acid groups. The polymerizable composition according to claim 1, wherein the photopolymerization initiator having the structure of the general formula (2) is a compound having a structure of the following general formula (3).

In the general formula (3), M ⁺ Represents an onium cation, R ¹ , R ² And R ⁴ Each independently represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. Ar represents an aromatic group or a heterocyclic group, Ar, R ¹ , R ² And R ⁴ Among them, at least one has one or more carboxylic acid groups. The polymerizable composition according to claim 1, wherein the photopolymerization initiator having the structure of the general formula (2) is a compound having a structure of the following general formula (4).

In the general formula (4), M ⁺ Represents an onium cation, R ¹ , R ² , R ⁴ And R ⁵ Each independently represents a monovalent substituent composed of a hydrogen atom or a nonmetallic atom. Ar represents an aromatic group or a heterocyclic group. Ar, R ¹ , R ² , R ⁴ And R ⁵ May or may not have a carboxylic acid group. M ⁺ The polymerizable composition according to any one of claims 1 to 3, wherein the onium cation represented by formula (1) is a sulfonium cation. A lithographic printing plate precursor comprising a support and a photosensitive layer comprising the polymerizable composition according to any one of claims 1 to 4 . The lithographic printing plate precursor according to claim 5 , further comprising a protective layer on the photosensitive layer.