JP2010084046A - Method of manufacturing polymer and polymer for lithographic printing plate precursor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a polymer which has an equal effect as compared to that of a polymer manufactured by using NMP when applied to a lithographic printing plate, and to provide a polymer for a lithographic printing plate. <P>SOLUTION: A solution represented by formula (1), in which a quaternary ammonium salt monomer is dissolved, is added dropwise to a solution represented by formula (2) in which a monomer is dissolved. A solvent dissolving the monomer is preferably a mixed solvent composed of a ketone-based solvent and an alcohol based solvent. (In the formula, R<SP>11</SP>is hydrogen atom or the like; L<SP>1</SP>is a single bond or divalent linking group; R<SP>12</SP>-R<SP>14</SP>are each independently hydrogen atom or the like; X<SP>-</SP>is an ion pair required for neutralizing a charge; R<SP>21</SP>is hydrogen atom or the like; and R<SP>22</SP>is an ester group or the like). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polymer production method and a polymer for a lithographic printing plate precursor obtained by the production method.

In general, a lithographic printing plate comprises an oleophilic image area that receives ink in the printing process and a hydrophilic non-image area that receives dampening water. Lithographic printing utilizes the property that water and oil-based inks repel each other, so that the oleophilic image area of the lithographic printing plate is the ink receiving area, and the hydrophilic non-image area is dampened with the water receiving area (ink non-receiving area). In this method, a difference in ink adhesion is caused on the surface of the lithographic printing plate, and after ink is applied only to the image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, conventionally, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support has been widely used. Usually, after exposing the lithographic printing plate precursor through an original image such as a lithographic film, the image recording layer to be an image portion is left, and the other unnecessary image recording layer is removed with an alkaline developer or an organic solvent. Plate making is performed by a method of exposing the surface of the hydrophilic support by dissolving and removing to obtain a lithographic printing plate.

  In the conventional plate making process of a lithographic printing plate precursor, after exposure, a step of dissolving and removing unnecessary image recording layers with a developer or the like is necessary, but such additional wet processing is made unnecessary or Simplification is cited as one of the issues. In particular, in recent years, disposal of waste liquids discharged with wet processing has become a major concern for the entire industry due to consideration for the global environment, and therefore, the demand for solving the above-mentioned problems has become stronger.

On the other hand, as one of simple plate making methods, an image recording layer that can remove the image recording layer of the lithographic printing plate precursor in a normal printing process is used. A method called on-press development has been proposed in which an image recording layer corresponding to a portion is removed to obtain a lithographic printing plate.
As a specific method of on-press development, for example, a method of using a lithographic printing plate precursor having an image recording layer that can be dissolved or dispersed in dampening water, an ink solvent, or an emulsion of dampening water and ink , A method of mechanically removing the image recording layer by contact with rollers or a blanket cylinder of a printing press, cohesion of the image recording layer by penetration of dampening water, ink solvent, etc. There is a method in which after the adhesive force is weakened, the image recording layer is mechanically removed by contact with rollers or a blanket cylinder.
In the present specification, unless otherwise specified, the “development processing step” means using a device other than a printing machine (usually an automatic developing machine) and contacting a liquid (usually an alkaline developer). This refers to the process of removing the infrared laser unexposed portion of the lithographic printing plate precursor and exposing the surface of the hydrophilic support, and “on-press development” refers to a liquid (usually printing ink and (Or dampening water) to remove the infrared laser unexposed portion of the lithographic printing plate precursor and expose the surface of the hydrophilic support.

On the other hand, in recent years, digitization techniques for electronically processing, storing, and outputting image information by a computer have become widespread, and various new image output methods corresponding to such digitization techniques are put into practical use. It is becoming. Along with this, digitized image information is carried by high-convergence radiation such as laser light, and the lithographic printing plate precursor is scanned and exposed with that light, directly without using a lithographic film. Computer-to-plate (CTP) technology has been attracting attention. Therefore, obtaining a lithographic printing plate precursor adapted to such a technique is one of the important technical issues.
As described above, in recent years, the simplification, drying, and no processing of plate making operations have become more desirable than ever in terms of consideration for the global environment and adaptation to digitalization. It is coming.

  As a lithographic printing plate precursor adapted to the above-mentioned demand, a lithographic printing plate precursor having a light and / or heat-polymerizable image recording layer is used. In these lithographic printing plate precursors, a protective layer (overcoat layer) is provided on the image recording layer in order to impart oxygen barrier properties, prevent scratches in the image recording layer, and prevent ablation that occurs during high-illuminance laser exposure. Provided. Examples of the protective layer material include water-soluble acrylic resins such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl imidazole, and polyacrylic acid, gelatin, gum arabic, and cellulose polymers (eg, carboxymethyl cellulose). It is known that by adding a layered compound such as mica to these, the oxygen barrier property is improved and the occurrence of scratches in the image recording layer is further prevented (see, for example, Patent Documents 1 and 2).

However, when a layered compound is used for the protective layer, one or a plurality of performances such as an initial printing property, an in-printing property, a developing property, and an on-press developing property may be deteriorated. . In particular, when water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, and cellulose-based polymers that are suitably used as a protective layer and layered compounds such as mica are added thereto, good oxygen barrier properties are exhibited. However, the development property and the inking property are often lowered, and this improvement is one of the important technical problems.
In order to improve the reduction in wearability, it has been proposed to contain a phosphonium compound in an image recording layer or a protective layer (see, for example, Patent Documents 3 and 4). It is still inadequate in terms of bringing the sex to an excellent level.

  Therefore, the present applicant, in the on-press development type lithographic printing plate precursor having a protective layer containing a layered compound, by adding a polymer containing a structural unit having an ammonium structure to the image recording layer or the protective layer, The inventor has found that printing durability, inking property, and on-press developability are all further improved.

  In producing such a polymer containing a structural unit having an ammonium structure, it is advantageous in terms of solubility to use N-methylpyrrolidone (NMP) as a reaction solvent, but NMP is advantageous in terms of price, safety, etc. Not necessarily enough in terms. Moreover, since the boiling point is high, it may be unsuitable for the use in the form which apply | coats to a board | substrate.

  For example, the use of a mixed solvent of a ketone solvent such as methyl ethyl ketone (MEK) and an alcohol solvent, which are readily available as a reaction solvent, was examined. However, simply changing NMP as a reaction solvent to a mixed solvent of a ketone solvent and an alcohol solvent does not yield a desired copolymerized polymer, and even when applied to a lithographic printing plate precursor, NMP is used. In some cases, the effect could not be obtained as compared with the polymer produced.

Patent Document 5 describes that cyclohexanone is used as a reaction solvent when a monomer having an ammonium structure and another copolymerizable monomer are polymerized. However, nothing is described about applying the polymer obtained by the polymerization method described in Patent Document 5 to a lithographic printing plate precursor.
JP 2001-171250 A JP 2005-119273 A JP 2006-297907 A JP 2007-50660 A JP 2004-198717 A

  An object of the present invention is to provide a polymer production method and a lithographic printing method in which a polymer in a desired copolymerized state is obtained, and even when applied to a lithographic printing plate precursor, it has the same effect as a polymer produced using NMP. It is to provide a polymer for an original plate.

As a result of intensive investigations to achieve the above object, the present inventors have obtained a desired copolymerized polymer by devising a method for adding a monomer component to a polymerization reaction system, and applied it to a lithographic printing plate precursor. However, it has been found that a polymer having an effect equivalent to that of a polymer produced using NMP can be obtained, and the present invention has been completed.
That is, the present invention is as follows.

(1) A method for producing a polymer by polymerizing a quaternary ammonium salt monomer represented by the following general formula (1) and a monomer represented by the following general formula (2), wherein the following general formula (2) A polymer in which a solution in which a quaternary ammonium salt monomer represented by the following general formula (1) is dissolved is dropped into a solution in which the monomer represented by formula (1) is dissolved, and the dropping speed is changed at least once. Manufacturing method.

(In General Formula (1), R ¹¹ represents a hydrogen atom, an alkyl group, or a halogen atom. L ¹ represents a single bond or a divalent linking group, and R ¹² , R ^13, and R ¹⁴ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, or .R ¹² representing an alkylidene group, at least two selected from R ¹³ and R ¹⁴ may be bonded to form a ring together, .X ^- is This represents a counter ion necessary for neutralizing the charge, wherein R ²¹ represents a hydrogen atom, an alkyl group, or a halogen atom, and R ²² represents an ester group, an amide group, a cyano group, or a hydroxy group. Or an aryl group.)

(2) The method for producing a polymer according to (1), wherein when the dropping speed is changed, the dropping speed is changed.
(3) The solvent for dissolving the monomer is a mixed solvent of a ketone solvent and an alcohol solvent, and the ratio is ketone solvent: alcohol solvent = 70: 30 to 30:70. The manufacturing method of the polymer of said (1).
(4) The method for producing a polymer according to (1), wherein in the general formula (1), L ¹ is a group having at least a group selected from a phenylene group, a carbonyloxy group, and a carbonylimino group.
(5) In the general formula (1), X ⁻ is selected from a halide ion, a carboxylate ion, an alkyl sulfonate ion, an alkyl phosphate ion, a phosphonate ion, an aryl sulfonate ion, PF ₆ ^— and BF ₄ ^—. (1) The method for producing a polymer according to (1) above.
(6) The method for producing a polymer according to (1), wherein in the general formula (2), R ²² is an ester group, an amide group or a phenyl group which may have a substituent.
(7) The method for producing a polymer according to (1), wherein in the general formula (2), R ²² is a group containing a polyalkyleneoxy group.

(8) A lithographic printing plate precursor polymer produced by polymerizing a quaternary ammonium salt monomer represented by the following general formula (1) and a monomer represented by the following general formula (2): A solution in which a quaternary ammonium salt monomer represented by the following general formula (1) is dissolved is dropped into a solution in which the monomer represented by the formula (2) is dissolved, and the dropping speed is changed at least once. A polymer for a lithographic printing plate precursor produced by

(In General Formula (1), R ¹¹ represents a hydrogen atom, an alkyl group, or a halogen atom. L ¹ represents a single bond or a divalent linking group, and R ¹² , R ^13, and R ¹⁴ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, or .R ¹² representing an alkylidene group, at least two selected from R ¹³ and R ¹⁴ may be bonded to form a ring together, .X ^- is This represents a counter ion necessary for neutralizing the charge, wherein R ²¹ represents a hydrogen atom, an alkyl group, or a halogen atom, and R ²² represents an ester group, an amide group, a cyano group, or a hydroxy group. Or an aryl group.)

  According to the present invention, even when applied to a lithographic printing plate precursor in a desirable copolymerization state, a polymer having an effect equivalent to that of a polymer produced using NMP was obtained.

  The method for producing a polymer of the present invention comprises the following general formula (1) in a solution in which a monomer represented by the following general formula (2) (hereinafter also simply referred to as “copolymerization monomer” or “monomer (2)”) is dissolved. ) Quaternary ammonium salt monomer (hereinafter, also simply referred to as “quaternary ammonium salt-containing monomer” or “monomer (1)”) is added dropwise.

(In General Formula (1), R ¹¹ represents a hydrogen atom, an alkyl group, or a halogen atom. L ¹ represents a single bond or a divalent linking group, and R ¹² , R ^13, and R ¹⁴ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, or .R ¹² representing an alkylidene group, at least two selected from R ¹³ and R ¹⁴ may be bonded to form a ring together, .X ^- is This represents a counter ion necessary for neutralizing the charge, wherein R ²¹ represents a hydrogen atom, an alkyl group, or a halogen atom, and R ²² represents an ester group, an amide group, a cyano group, or a hydroxy group. Or an aryl group.)

Although it does not specifically limit as a solvent which melt | dissolves the said monomer (2) and the monomer (1), respectively, For example, the mixed solvent of a ketone solvent and an alcohol solvent is preferable.
A ketone solvent used in a mixed solvent of a ketone solvent and an alcohol solvent (hereinafter also simply referred to as “solvent” or “reaction solvent”) is not particularly limited, but is not limited to methyl ethyl ketone (MEK), pinacolone, 2-pentanone, Examples include 3-pentanone, 2-heptanone, 3-heptanone, 2-octanone, cyclohexanone, cyclopentanone, methyl isobutyl ketone, 2-propylcyclohexanone, and 2,6-dimethyl-4-heptanone.
The alcohol solvent is not particularly limited, but methoxypropylene glycol (MFG), 1-methoxy-2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2 -(2-methoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethanol, 3-hydroxytetrahydrofuran, 2-hydroxyethyl acetate, 2-hydroxypropyl acetate, 2- (2-hydroxyethoxy) ethyl acetate, 2-cyclohex Siloxyethanol, 1-methoxy-2-methyl-2-propanol, 1-propoxy-2-propanol and the like can be mentioned.

  The mixing ratio of the ketone solvent and the alcohol solvent is not particularly limited, but is preferably ketone solvent: alcohol solvent = 90: 10 to 10:90, more preferably 80:20 to 20: 80, more preferably 70:30 to 30:70.

  The dropping condition of the reaction solvent in which the monomer (1) is dissolved in the reaction solvent in which the monomer (2) is dissolved is not particularly limited, but it is preferable to change the dropping speed at least once, and the dropping speed is 2 to 5 stages. It is more preferable to change to. When changing the dropping speed, it is preferable to change the dropping speed so that the subsequent dropping speed is slower than the preceding stage.

In the polymerization reaction in the present invention, it is preferable to use a polymerization initiator. As the polymerization initiator, the type, addition amount, and other addition conditions can be appropriately selected depending on the monomer, solvent, and reaction scale used in the polymerization reaction.
The polymerization reaction temperature is not particularly limited, and can be appropriately selected depending on the monomer, polymerization initiator, solvent, and reaction scale to be used, but a range of 60 to 80 ° C. is usually preferable.

Next, each monomer used in the method for producing a polymer of the present invention will be described in detail.
[Monomer (1) Represented by General Formula (1)]
In the monomer (1) represented by the general formula (1), R ¹¹ represents a hydrogen atom or a substituent. L ¹ represents a divalent linking group, and R ¹² , R ¹³ and R ¹⁴ each independently represents a hydrogen atom or a substituent. X ⁻ represents a counter ion necessary for neutralizing the electric charge.

R ¹¹ will be described. In general formula (1), R ¹¹ represents a hydrogen atom or a substituent. Preferably, it represents a hydrogen atom, an alkyl group, an aryl group, a substituted carbonyl group, a substituted oxy group, a heterocyclic group or a halogen atom, more preferably a hydrogen atom, an alkyl group or a halogen atom, particularly preferably a hydrogen atom or Represents an alkyl group.

Preferred examples of the alkyl group represented by R ¹¹ 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 groups.

The aryl group represented by R ¹¹ preferably represents a substituted or unsubstituted aryl group having 5 to 20 carbon atoms, more preferably 6 to 18 carbon atoms, and particularly preferably 6 to 12 carbon atoms. The aryl group represented by R ¹¹ may further have a substituent.
Preferred examples include phenyl group, 4-methylphenyl group, 4-methoxyphenyl group, 4-chlorophenyl group, 4- (dimethylamino) group, 1-naphthyl group, 2-naphthyl group, biphenyl group, xylyl group, mesityl. Group, cumenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methyl Aminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, cyanopheny Group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, phosphate Hona preparative phenyl group, and the like.

The heterocyclic group represented by R ¹¹ is preferably a 3- to 8-membered ring, more preferably a 3- to 6-membered ring, and particularly preferably a 5- to 6-membered ring. Moreover, as a kind of hetero atom which comprises a heterocyclic ring, it is preferable that a nitrogen atom, an oxygen atom, or a sulfur atom is included. The heterocyclic group represented by R ¹¹ may further have a substituent.
Preferred examples 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, benzoiso Xazole 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, acylidin 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.

The substituted carbonyl group represented by R ¹¹ is preferably a group represented by (R ¹⁵ —CO—). R ¹⁵ represents a hydrogen atom or a substituent. Preferred examples of R ¹¹ 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. 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 substituted carbonyl groups include formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-ary. A rucarbamoyl group is exemplified, and particularly preferred are a formyl group, an acyl group, an alkoxycarbonyl group, and an aryloxycarbonyl group.
Preferred examples of R ¹¹ include formyl group, acetyl group, benzoyl group, carboxyl group, methoxycarbonyl group, ethoxycarbonyl group, allyloxycarbonyl group, dimethylaminophenylethenylcarbonyl group, methoxycarbonylmethoxycarbonyl group, N- Examples thereof include a methylcarbamoyl group, an N-phenylcarbamoyl group, an N, N-diethylcarbamoyl group, and a morpholinocarbonyl group.

The substituted oxy group represented by R ¹¹ is preferably a group represented by (R ¹⁶ O—). R ¹⁶ represents a hydrogen atom or a substituent. Preferred examples of the substituted oxy group include hydroxyl group, alkoxy group, aryloxy group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N- Examples thereof include a diarylcarbamoyloxy group, an N-alkyl-N-arylcarbamoyloxy group, an alkylsulfoxy group, an arylsulfoxy group, a phosphonooxy group, and a phosphonatoxy group. 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. Specific examples of the acyl group when the substituted oxy group represented by R ¹¹ represents an acyloxy group include the examples where R ¹¹ represents a substituted carbonyl group. 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 halogen atom represented by R ¹¹ is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, more preferably a fluorine atom, a chlorine atom or a bromine atom, and a fluorine atom, a chlorine atom or a bromine atom. It is particularly preferred that

When the group represented by R ¹¹ can be substituted, it may further have a substituent. Any kind of substituent can be selected as long as it is a substitutable group. For example, an alkyl group, aryl group, alkenyl group, alkynyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom) ), Hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N , N-Diarylcarbamoyloxy group, N-alkyl-N- Lillecarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N ′ -Dialkylureido group, N'-arylureido group, N ', N'-diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl -N-alkylureido group, N'-alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl -N-alkylureido group, N'-aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', '- diaryl -N- arylureido group, N'- alkyl -N'- aryl -N- alkylureido group, N'- alkyl -N'- aryl -N- arylureido group,

Alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-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 (scan Phonato 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, hereinafter the same”, 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 its conjugated base group (referred to as phosphonatooxy group), dialkylphosphono group (-OPO ₃ H (alkyl) _2), diaryl Suhonookishi 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.
These groups may be further combined to form a composite substituent.

Particularly preferred as R ¹¹ is a hydrogen atom or a methyl group.

R ¹² , R ¹³ and R ¹⁴ will be described. R ¹² , R ¹³ and R ¹⁴ each independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group or an alkylidene group, more preferably a hydrogen atom or an alkyl group, particularly preferably Represents an alkyl group. Provided that one of R ¹² , R ¹³ and R ¹⁴ is an alkylidene group (that is, a divalent group derived by further removing one hydrogen atom from a carbon atom having a free valence of a monovalent hydrocarbon group). ) Represents one remaining group that can be substituted for N, and therefore one of R ¹² , R ^13, and R ¹⁴ does not exist. R ¹² , R ¹³ and R ¹⁴ may be bonded to each other to form a ring.

When R ¹² , R ¹³ and R ¹⁴ represent an alkyl group, preferred examples include methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group, neo-pentyl group, cyclopentyl group, n-hexyl group, i-hexyl group , Sec-hexyl group, t-hexyl group, cyclohexyl group, cyclohexylmethyl group, cyclopentyl group, cyclopropylmethyl group, cyclohexylmethyl group, cyclobutylmethyl group, linear or branched heptyl group, cyclopentylethyl group, linear or Branched octyl group, linear or branched nonyl group, linear or branched decyl group, dodecyl group, tetradecyl group A syl group, a hexadecyl group, an octadecyl group, an icosyl group, and the like can be mentioned. More preferred examples include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, i -Butyl group, sec-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group, neo-pentyl group, cyclopentyl group, n-hexyl group, Examples thereof include i-hexyl group, sec-hexyl group, t-hexyl group, cyclohexyl group, cyclohexylmethyl group, linear or branched heptyl group, cyclopentylethyl group, linear or branched octyl group, and particularly preferable. Examples include methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group i-butyl group, sec-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group, neo-pentyl group, cyclopentyl group, n-hexyl group I-hexyl group, sec-hexyl group, t-hexyl group and cyclohexyl group.

The group represented by R ¹² , R ¹³ and R ¹⁴ may have a substituent. As the substituent, any substitutable group can be selected. Preferred examples include trifluoromethyl group, fluoro group, chloro group, bromo group, methoxy group, hydroxyl group, nitro group, vinyl group, dimethyl group. An amino group, an aryl group, a methoxycarbonyl group, an ethoxycarbonyl group, etc. can be mentioned, and more preferred examples include a fluoro group, a chloro group, a bromo group, a methoxy group, a hydroxyl group, a vinyl group, a dimethylamino group, and a phenyl group. Methoxycarbonyl group, ethoxycarbonyl group and the like, and particularly preferred examples include fluoro group, chloro group, bromo group, methoxy group, hydroxyl group, vinyl group, phenyl group, methoxycarbonyl group, ethoxycarbonyl group, etc. Can be mentioned. These groups may be further substituted with the same substituent.
Preferred examples of the group represented by R ¹² , R ¹³ and R ¹⁴ having a substituent include a benzyl group, a 4-methylbenzyl group, a 3-methylbenzyl group, a 2-methylbenzyl group, and 4-methoxybenzyl. Group, 3-methoxybenzyl group, 2-methoxybenzyl group, 4-dimethylaminobenzyl group, 3,5-dimethylbenzyl group, 3,4,5-trimethylbenzyl group, 4-phenylbenzyl group, 4-phenoxybenzyl, And so on.
Further preferred examples include benzyl group, 4-methylbenzyl group, 3-methylbenzyl group, 2-methylbenzyl group, 4-methoxybenzyl group, 3-methoxybenzyl group, 2-methoxybenzyl group, 4-dimethylaminobenzyl. Group, 3,5-dimethylbenzyl group, and the like.
Particularly preferred examples include benzyl group, 4-methylbenzyl group, 3-methylbenzyl group, 2-methylbenzyl group, 4-methoxybenzyl group, 3-methoxybenzyl group, 2-methoxybenzyl group, 4-dimethylaminobenzyl. Group, and the like.

The groups represented by R ¹² , R ¹³ and R ¹⁴ may be the same or different, or two of the three may be the same, and any combination can be selected. R ¹² , R ¹³ and R ¹⁴ are all preferably alkyl groups having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and particularly preferably 1 to 8 carbon atoms. R ¹² , R ¹³ and R ¹⁴ may all be the same or different.

In the present invention, examples of preferable combinations of groups represented by R ¹² , R ¹³ and R ¹⁴ include (methyl group, methyl group, and methyl group combination), (methyl group, methyl group, and ethyl group). Group combination), (combination of methyl group, methyl group, and propyl group), (combination of methyl group, methyl group, and isopropyl group), (combination of methyl group, methyl group, and butyl group), (Combination of methyl group, methyl group, and isobutyl group), (combination of methyl group, methyl group, and pentyl group), (combination of methyl group, methyl group, and hexyl group), (methyl group, methyl group) Group and benzyl group) (ethyl group, ethyl group and methyl group combination), (ethyl group, ethyl group and methyl group combination), (ethyl group, ethyl group, And combinations of ethyl groups), (combination of ethyl groups, ethyl groups, and propyl groups), (combination of ethyl groups, ethyl groups, and isopropyl groups), (ethyl groups, ethyl groups, and butyl groups) Combination), (ethyl group, ethyl group, and isobutyl group combination), (ethyl group, ethyl group, and pentyl group combination), (ethyl group, ethyl group, and hexyl group combination), (ethyl A combination of a group, an ethyl group, and a benzyl group).
Examples of further preferred combinations of the groups represented by R ¹² , R ¹³ and R ¹⁴ include (a combination of methyl group, methyl group and methyl group), (a combination of methyl group, methyl group and ethyl group) ), (Combination of methyl, methyl and propyl), (combination of methyl, methyl and isopropyl), (combination of methyl, methyl and butyl), (methyl) , Methyl group and isobutyl group), (methyl group, methyl group and pentyl group combination), (methyl group, methyl group and hexyl group combination), (methyl group, methyl group and And a combination of benzyl groups).
Examples of particularly preferred combinations of the groups represented by R ¹² , R ¹³ and R ¹⁴ include (combination of methyl group, methyl group and methyl group), (combination of methyl group, methyl group and ethyl group) ), (Combination of methyl, methyl and propyl), (combination of methyl, methyl and isopropyl), (combination of methyl, methyl and butyl), (methyl) , A combination of methyl group and isobutyl group), (a combination of methyl group, methyl group and pentyl group).

When R ¹² , R ¹³ and R ¹⁴ represent an aryl group or a heterocyclic group, preferred examples of R ¹¹ described above can be given as preferred examples.

Preferred when R ¹² , R ¹³ and R ¹⁴ represent an alkylidene group (that is, a divalent group derived by removing one hydrogen atom from a carbon atom having the free valence of a monovalent hydrocarbon group). Examples include methylene, ethylene, propylene, and the like. More preferably, examples in which a ring is formed by bonding to the remaining group capable of substituting N (pyridinium, pyrazinium, thiazolinium, imidazolium, oxazolinium, indolinium, isoindolinium, benzoimidazolinium, etc.) are given. be able to.

As an example in which R ¹² , R ¹³ and R ¹⁴ are bonded to each other to form a ring, the nitrogen-containing complex formed when one of R ¹² , R ¹³ and R ¹⁴ described above is an alkylidene group. Examples of the ring include pyrrolidinium, imidazolidinium, piperidinium, piperazinium, morpholinium, and indolinium.

L ¹ will be described. L ¹ represents a single bond or a divalent linking group.
When L ¹ is a divalent linking group, 1 to 60 carbon atoms, 0 to 10 nitrogen atoms, 0 to 50 oxygen atoms, 1 to 100 hydrogen atoms , And 0 to 20 sulfur atoms.
More specifically, the following divalent groups or groups formed by appropriately combining these groups can be exemplified.

More preferable examples of the divalent linking group represented by L ¹ include divalent groups represented by the following structural formulas.

X ^- will be described. X ⁻ represents a counter ion necessary for neutralizing the electric charge.
X ⁻ includes a halide ion (F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ ), a carboxylate ion having 1 to 100 carbon atoms, an alkyl sulfonate ion having 1 to 100 carbon atoms, and an aryl having 6 to 100 carbon atoms. Sulfonate ion, C1-C100 alkyl sulfate ion, sulfate ion, hydrogen sulfate ion, sulfite ion, hydrogen sulfite ion, phosphate ion, hydrogen phosphate ion, C1-C100 alkyl phosphate ion, carbon number 6-100 aryl phosphate ions, C1-C100 alkyl phosphonate ions, C 6-100 aryl phosphonate ions, hydroxide ions, carbonate ions, bicarbonate ions, PF ₆ ⁻ , BF ₄ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , and combinations thereof are preferred,
Halide ion (F ⁻ , Cl ⁻ , Br ⁻ ), C 1 -70 carboxylate ion, C 1 -70 alkyl sulfonate ion, C 6 -70 aryl sulfonate ion, C 1 -C 1 70 alkyl sulfate ions, sulfate ions, phosphate ions, alkyl phosphate ions having 1 to 70 carbon atoms, alkyl phosphonate ions having 1 to 70 carbon atoms, aryl phosphonate ions having _{6 to} 70 carbon atoms, PF ₆ ⁻ , BF ₄ ⁻ , and a combination thereof are more preferable, a carboxylic acid ion having 1 to 50 carbon atoms, an alkyl sulfonic acid ion having 1 to 50 carbon atoms, an aryl sulfonic acid ion having 6 to 50 carbon atoms, and 1 to 50 carbon atoms. Alkyl sulfate ion, sulfate ion, phosphate ion, alkyl phosphate ion having 1 to 50 carbon atoms, alkyl phosphonate ion having 1 to 50 carbon atoms, carbon number Particularly preferred are 6 to 50 arylphosphonate ions, PF ₆ ⁻ , BF ₄ ⁻ , and combinations thereof.

When X ⁻ represents a carboxylate ion, an alkyl sulfonate ion, an aryl sulfonate ion, an alkyl sulfate ion, an alkyl phosphate ion, an alkyl phosphonate ion, or an aryl phosphonate ion, preferred examples include the following. be able to. However, it is not limited to these.

  The repeating unit having an ammonium structure contained in the polymer obtained by the production method of the present invention more preferably has a structure represented by the following general formula (6), (7) or (8).

Formula (6), (7) and (8) in, R ^{11, R 12, R 13, R} 14 and X ^- is, R ¹¹ in the general formula (1) ^{in, R 12, R 13, R} 14 and X ^- as synonymous. Further, L is the same meaning as L ¹ in the general formula (1).

[Monomer (2) Represented by General Formula (2)]
In the monomer (1) represented by the general formula (1), R ²¹ represents a hydrogen atom or a substituent. R ²² represents a substituent.
Preferred examples of R ²¹ include the preferred examples of R ¹¹ in general formula (1). Preferable examples of R ²² include an ester group, an amide group, a cyano group, a hydroxy group, or an aryl group. Of these, an ester group, an amide group, or a phenyl group which may have a substituent is preferable.
Examples of the substituent for the phenyl group include those listed as the substituents for R ^{12 to} R ^{14 in} the general formula (1), alkyl groups, aralkyl groups, alkoxy groups, acetoxymethyl groups, and the like. Moreover, the substituent of the phenyl group may further have a substituent.

  Examples of the monomer (2) represented by the general formula (2) include acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, N-substituted acrylamides, N-substituted methacrylamides, N, Examples thereof include N-2 substituted acrylamides, N, N-2 substituted methacrylamides, styrenes, acrylonitriles, methacrylonitriles and the like. Preferably, acrylic esters, methacrylic esters, acrylamides, methacrylamides, N-substituted acrylamides, N-substituted methacrylamides, N, N-2 substituted acrylamides, N, N-2 substituted methacrylamides And styrenes.

  Specifically, for example, acrylic esters such as alkyl acrylate (the alkyl group preferably has 1 to 20 carbon atoms), (for example, methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid) Butyl, amyl acrylate, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate Glycidyl acrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.), aryl acrylate (eg phenyl Methacrylic acid esters (for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl) such as alkyl methacrylate (the alkyl group preferably has 1 to 20 carbon atoms). Methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, Furfuryl methacrylate, tetrahydrofurfuryl meta Relates, etc.), aryl methacrylates (eg, phenyl methacrylate, cresyl methacrylate, naphthyl methacrylate, etc.), styrenes such as styrene, alkyl styrene (eg, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl) Styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, benzyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, etc.), alkoxy styrene (for example, methoxy styrene, 4-methoxy-3-methyl styrene, Dimethoxystyrene), halogen styrene (eg, chlorostyrene, dichlorostyrene, trichlorostyrene) , Tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, etc.) , Acrylonitrile, methacrylonitrile acrylic acid, radically polymerizable compounds containing carboxylic acid (acrylic acid, methacrylic acid, itaconic acid, p-carboxylstyrene, and metal salts of these acid groups, ammonium salt compounds, etc.) .

Moreover, it is preferable that the general formula (2) has a polyalkyleneoxy group in the molecule. Examples of polyalkyleneoxy groups include -O- (CH ₂ CH ₂ -O-) _n -R ²³ , -O- (CH (CH ₃ ) CH ₂ -O-) _n -R ²³ , -O- ( A group represented by CH ₂ CH (CH ₃ ) —O—) _n —R ²³ is exemplified. Here, n is preferably 1 to 10, more preferably 1 to 6, still more preferably 1 to 4, and particularly preferably 1 to 2. Here, n may be single or a mixture of a plurality of types, and in the case of a mixture, n represents an average value. R ²³ preferably represents a substituent having 1 to 30 carbon atoms, more preferably 1 to 20, more preferably 1 to 10 carbon atoms, and particularly preferably 1 to 10 carbon atoms.
Examples of R ²³ include methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group, neo-pentyl group, cyclopentyl group, n-hexyl group, i-hexyl group, sec-hexyl group, t-hexyl group, cyclohexyl group Cyclohexylmethyl group, cyclopentyl group, cyclopropylmethyl group, cyclohexylmethyl group, cyclobutylmethyl group, linear or branched heptyl group, cyclopentylethyl group, linear or branched octyl group, linear or branched nonyl group, Linear or branched decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, icosi And more preferable examples include methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i-butyl group, sec-butyl group, t -Butyl group, cyclobutyl group, n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group, neo-pentyl group, cyclopentyl group, n-hexyl group, i-hexyl group, sec-hexyl group, Examples thereof include a t-hexyl group, a cyclohexyl group, a cyclohexylmethyl group, a linear or branched heptyl group, a cyclopentylethyl group, a linear or branched octyl group, and particularly preferable examples include a methyl group, an ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, n-hexyl group, linear or branched Octyl, and the like.

[Other copolymerization monomers]
In the method for producing a polymer of the present invention, in addition to the monomer (1) and the monomer (2), in order to improve various performances such as image strength of a lithographic printing plate precursor, the effects of the present invention are not impaired. Furthermore, other monomers may be copolymerized. Examples of the other monomer to be copolymerized include a copolymerizable monomer having a polymerizable group.

<Copolymerized monomer having a polymerizable group>
Examples of the copolymerizable monomer having a polymerizable group include those having an ethylenically unsaturated group in addition to the polymerizable group involved in the copolymerization.
The ethylenically unsaturated group as used herein represents a known arbitrary group having a substituted or unsubstituted ethylene group, and preferred examples include acryloyl group, methacryloyl group, styryl group, allyl group, vinyl group, acrylonitrile group. Methacrylonitrile group, maleic acid structure, maleimide structure, cinnamic acid structure and the like.
The ethylenically unsaturated group and the monomer main body may be bonded via an arbitrary linking group, but a preferable example is a linking group represented by L ¹ in the general formula (1). it can.

  When the copolymerizable monomer having a polymerizable group has an ethylenically unsaturated group, the ethylenically unsaturated group preferably has a structure represented by the following general formula (3).

In General Formula (3), R ^{31 to} R ³³ each independently represents a hydrogen atom or a substituent. X ¹ and Y ¹ each independently represents a single bond or a divalent linking group. Z represents a linking group represented by the following general formula (4) or general formula (5). In the general formula (4), R ^{41 to} R ⁴⁵ each independently represents a hydrogen atom or a monovalent substituent. In General Formula (5), R ^{51 to} R ⁵⁶ each independently represent a hydrogen atom or a monovalent substituent. A and B each independently represent a hydrogen atom or a monovalent substituent. However, at least one of A and B is a hydroxyl group.

The substituent represented by R ^{31 to} R ³³ in the general formula (3) may be any substituent as long as it is a substitutable group, but is a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom). , Amino group, substituted amino group, substituted carbonyl group, substituted oxy group, mercapto group, substituted thio group, silyl group, nitro group, cyano group, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, sulfo group Preferred examples include a substituted sulfonyl group, a sulfonate group, a substituted sulfinyl group, a phosphono group, a substituted phosphono group, a phosphonato group, and a substituted phosphonato group.

More preferred examples of R ^{31 to} R ³³ include preferred examples of R ¹¹ in the general formula (1).
R ³¹ is particularly preferably a hydrogen atom or a methyl group, and R ³² and R ³³ are particularly preferably a hydrogen atom.

In the general formula (3), X ¹ represents a linking group between the copolymer monomer main body and the group represented by Z. Preferable examples of X ¹ and Y ¹ include preferred examples of L ¹ in the general formula (1).

Preferable examples of R ^{41 to} R ⁴⁵ and R ^{51 to} R ^{56 in} the general formula (4) and the general formula (5) include preferable examples of R ¹¹ in the general formula (1). More preferably, they are a hydrogen atom and an alkyl group, and particularly preferably a hydrogen atom and an alkyl group having 6 or less carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, Isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, cyclohexyl group, etc.).

  One of A and B in the general formula (5) is particularly preferably a hydroxyl group and the other is a hydrogen atom.

  Although the preferable example of the structure which has an ethylenically unsaturated group in a side chain below is given, it is not limited to these.

In the method for producing a polymer of the present invention, the polymerization ratio of the monomer (1) and the monomer (2) is not particularly limited, but is preferably 1:99 to 99: 1, more preferably 5:95 to 95: 5 in molar ratio. More preferably, it is 5:95 to 80:20, still more preferably 10:90 to 50:50, and particularly preferably 20:80 to 40:60. Within these ranges, when applied to a lithographic printing plate precursor, the effects of excellent inking properties and on-press developability are remarkable while maintaining printing durability.
The polymerization ratio of the copolymerizable monomer having an ethylenically unsaturated group in the side chain is preferably 1:99 to a total of the monomer (1) and the monomer (2) having an ammonium structure in a molar ratio. The ratio is 50:50, more preferably 1:99 to 30:70, and more preferably 1:99 to 20:80. Within these ranges, when applied to a lithographic printing plate precursor, the effects of excellent inking properties and on-press developability are remarkable, and printing durability can be improved.

In the method for producing a polymer of the present invention, another copolymerization monomer may be further copolymerized within a range in which the effect of the present invention can be secured. Other copolymerization monomers that can be used in the present invention are not particularly limited as long as two or more copolymerizations are possible, but crotonic acid, maleic acid, (anhydrous) maleic acid, partially esterified maleic acid, partial Amidated maleic acid, aromatic hydrocarbon rings having vinyl groups, heteroaromatic rings having vinyl groups (vinyl imidazole, vinyl triazole, vinyl carbazoles, vinyl pyrrolidone, etc.), (meth) acrylonitrile, (meth) croton Nitriles, various benzoyloxyethylenes, various acetoxyethylenes, vinyl ketones, vinyl ethers and the like can be mentioned.
Although the number of types of monomers to be copolymerized is not particularly limited, 0 to 12 types are preferable, 0 to 8 types are more preferable, and 0 to 5 types are particularly preferable.

  The polymer obtained by the production method of the present invention has a reduced specific viscosity (unit: CSt / g / ml) determined by the following measurement method, preferably in the range of 5 to 120, and in the range of 10 to 110. More preferably, the thing of the range of 15-100 is especially preferable.

-Measurement method of reduced specific viscosity-
A 33% polymer solution (30% solution of a polymerization solvent) (3.33 g, 1 g as a solid content) is weighed into a 20 ml volumetric flask and diluted with N-methylpyrrolidone. This solution is put in an Ubbelohde reduced viscosity tube (viscosity constant = 0.010 cSt / s), and the time to flow down at 30 ° C. is measured. The calculation formula (“kinematic viscosity” = “viscosity constant” × “ Time of passage (second) ") was calculated by a conventional method.

Two or more kinds of polymers obtained by the production method of the present invention may be contained in the lithographic printing plate precursor.
The polymer obtained by the production method of the present invention (hereinafter also referred to as “specific polymer of the present invention”) is contained in at least one of the image recording layer and the protective layer of the lithographic printing plate precursor. Further, it may be contained in both the image recording layer and the protective layer. Furthermore, it may be contained in the undercoat layer in addition to the image recording layer and / or the protective layer.

  The content of the specific polymer of the present invention is preferably 0.0005% by mass to 30.0% by mass, more preferably 0.001% by mass to 20.0% by mass with respect to the total solid content of the layer to be contained. 0.002% by mass to 15.0% by mass is most preferable. Within this range, good inking properties can be obtained.

  Specific examples of the specific polymer of the present invention are shown below, but the specific polymer of the present invention is not limited to the following examples, and in combination with a coating liquid component for preparing a printing plate precursor, The structure and the amount added can be changed.

  The lithographic printing plate precursor to which the polymer obtained by the production method of the present invention can be applied (hereinafter, also simply referred to as “the lithographic printing plate precursor of the present invention”) is not particularly limited, but an image recording layer and a protective layer on a support. Those having layers in this order and containing a layered compound in the protective layer are preferred, and the polymer is contained in at least one of the image recording layer and the protective layer.

[Protective layer]
The lithographic printing plate precursor according to the invention has a protective layer (overcoat layer) on the image recording layer. In addition to the function of suppressing the image formation inhibition reaction by blocking oxygen, the protective layer also has functions such as preventing scratches in the image recording layer and preventing ablation during high-illuminance laser exposure. Hereinafter, the protective layer components and the like will be described.

  Usually, the exposure processing of a lithographic printing plate is carried out in the atmosphere. The image forming reaction in the image recording layer caused by the exposure process can be inhibited by low molecular compounds such as oxygen and basic substances present in the atmosphere. The protective layer prevents low molecular compounds such as oxygen and basic substances from entering the image recording layer, and as a result, suppresses image formation inhibition reaction in the air. Therefore, the property desired for the protective layer is to reduce the permeability of low-molecular compounds such as oxygen, and furthermore, the transparency of light used for exposure is good, and the adhesiveness with the image recording layer is excellent. And it can be easily removed in an on-press development process after exposure. The protective layer having such characteristics is described in, for example, US Pat. No. 3,458,311 and JP-B-55-49729.

  As the protective layer of the lithographic printing plate precursor according to the invention, known techniques described in JP2007-50660A, JP2008-191468A, and the like can be appropriately applied.

The coating amount of the protective layer, the coating amount after drying is preferably in the range of 0.01 to 10 g / m ^2, more preferably in the range of 0.02 to 3 g / m ^2, and most preferably 0. It is in the range of 02 to 1 g / m ² .

(Image recording layer)
The image recording layer of the present invention preferably contains (A) a sensitizing dye, (B) a polymerization initiator, and (C) a polymerizable monomer, and can record an image with a laser, particularly an infrared laser or a blue laser. Some are preferred.
Furthermore, the image recording layer of the present invention can contain other components in addition to these elements as required.
Hereinafter, formation of these image recording layer constituent components and the image recording layer will be described.

<(A) Sensitizing dye>
As the sensitizing dye contained in the image recording layer of the present invention, those having an absorption peak at 300 to 1200 nm are preferable, and those having an absorption peak at 360 to 850 nm are more preferable. Examples of such sensitizing dyes include spectral sensitizing dyes and the following dyes or pigments that absorb light from a light source and interact with a polymerization initiator.

  Preferred spectral sensitizing dyes or dyes include polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrolan, rhodamine B, rose bengal), cyanines (eg, thianes). Carbocyanine, oxacarbocyanine), merocyanines (eg, merocyanine, carbomerocyanine), thiazines (eg, thioene, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), phthalocyanines ( For example, phthalocyanine, metal phthalocyanine), porphyrins (for example, tetraphenylporphyrin, central metal-substituted porphyrin), chlorophylls (for example, chlorophyll, chlorophyllin, central gold) Substituted chlorophyll), metal complexes, anthraquinones (e.g., anthraquinone), Sutaariumu compound (such as Sutaariumu), and the like.

The sensitizing dye that absorbs light of 360 nm to 450 nm is 1.0% of the total solid content of the image recording layer.
It is preferably used in the range of ˜10.0% by mass. More preferably, it is the range of 1.5-5.0 mass%.

<(B) Polymerization initiator>
The polymerization initiator used in the present invention is a compound that generates radicals by light, heat, or both, and initiates and accelerates polymerization of a compound having a polymerizable unsaturated group. As the polymerization initiator that can be used in the present invention, a known thermal polymerization initiator, a compound having a bond with a small bond dissociation energy, a photopolymerization initiator, or the like can be used, and a radical that is suitably used in the present invention is generated. The compound that generates radicals by thermal energy,
The compound which starts and accelerates | stimulates superposition | polymerization of the compound which has a polymerizable unsaturated group. As the thermal radical generator according to the present invention, a known polymerization initiator, a compound having a bond with a small bond dissociation energy, or the like can be appropriately selected and used. Moreover, the compound which generate | occur | produces a radical can be used individually or in combination of 2 or more types.

Examples of the compound that generates radicals include organic halides, carbonyl compounds,
Examples thereof include organic peroxides, azo polymerization initiators, azide compounds, metallocene compounds, hexaarylbiimidazole compounds, organic borate compounds, disulfone compounds, oxime ester compounds, and onium salt compounds.

Specific examples of the organic halide include Wakabayashi et al., “Bull Chem. Soc.
Japan "42, 2924 (1969), U.S. Pat. No. 3,905,815,
JP-B-46-4605, JP-A-48-36281, JP-A-55-32070, JP-A-60-239736, JP-A-61-169835, JP-A-61-169837,
JP-A 62-58241, JP-A 62-212401, JP-A 63-70243,
JP-A-63-298339, M.K. P. Hutt “Journal of Het
The compound described in erocyclic Chemistry "1 (No3), (1970)" etc. is mentioned, As an especially preferable thing, the oxazole compound and s-triazine compound which substituted the trihalomethyl group are mentioned.

The polymerization initiator is not limited to the above, but a triazine-based initiator, an organic halogen compound, an oxime ester compound, a diazonium salt, an iodonium salt, and a sulfonium salt are more preferable from the viewpoints of reactivity and stability. Among these, from the viewpoint of improving the visibility of the printout image in combination with an infrared absorber, it is an onium salt and has an inorganic anion such as PF ₆ ⁻ , BF ₄ ⁻ or the like as a counter ion. Those are preferred. Furthermore, diaryliodonium is preferred as the onium because of its excellent color development.

These polymerization initiators are each 0.1 to 50% by mass with respect to the total solid content constituting the image recording layer.
More preferably, it is 0.5-30 mass%, More preferably, it can add in the ratio of 0.8-20 mass%. Within this range, good sensitivity and good stain resistance of the non-image area during printing can be obtained. These polymerization initiators may be used alone or in combination of two or more. Moreover, these polymerization initiators may be added to the same layer as other components, or another layer may be provided and added thereto.

<(C) Polymerizable monomer>
The polymerizable monomer that can be used in the present invention is a compound having at least one addition-polymerizable ethylenically unsaturated double bond, and a compound having at least one terminal ethylenically unsaturated bond, preferably two or more. Chosen from. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters thereof,
Amides are mentioned, and preferably, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and a monofunctional or polyfunctional compound. A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol 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.

About these polymerizable monomers, the details of usage, such as the structure, single use or combination, addition amount, etc. can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.
From the viewpoint of sensitivity, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image area, that is, the cured film, those having three or more functionalities are preferable, and furthermore, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrenic compound, vinyl ether type). A method of adjusting both sensitivity and strength by using a compound) is also effective.
Further, the selection and use method of the addition polymerization compound is also an important factor for the compatibility and dispersibility with other components (for example, binder polymer, initiator, colorant, etc.) in the image recording layer. In some cases, the compatibility can be improved by using a low-purity compound or by using two or more kinds in combination. In addition, a specific structure may be selected for the purpose of improving the adhesion of the substrate and the protective layer described later.
The polymerizable monomer is preferably 5 to 80% by mass with respect to the nonvolatile component in the image recording layer.
More preferably, it is used in the range of 25 to 75% by mass. These may be used alone or in combination of two or more. In addition, the use method of the polymerizable monomer is determined from the viewpoint of the degree of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface adhesiveness, etc.
The addition amount can be arbitrarily selected, and in some cases, a layer configuration and coating method such as undercoating and overcoating can also be carried out.

<Other image recording layer components>
The image recording layer of the present invention can further contain various additives as required. These will be described below.

<1> Microcapsule and Microgel In the present invention, several modes can be used as a method for incorporating the above-mentioned image recording layer constituents and other constituents described later into the image recording layer. One is a molecular dispersion type image recording layer in which the constituent components are dissolved and applied in an appropriate solvent as described in JP-A-2002-287334, for example. Another embodiment is disclosed in, for example, JP-A-2001-277.
As described in Japanese Patent Application Laid-Open No. 740 and Japanese Patent Application Laid-Open No. 2001-277742, it is a microcapsule type image recording layer in which all or part of the constituent components are encapsulated in a microcapsule and contained in the image recording layer. Further, in the microcapsule type image recording layer, the constituent component can be contained outside the microcapsule. Here, it is preferable that the microcapsule-type image recording layer includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule.
As still another embodiment, an embodiment in which the image recording layer contains crosslinked resin particles, that is, microgel, can be mentioned. The microgel may contain a part of the constituent component in and / or on the surface thereof. In particular, an embodiment in which (C) a polymerizable microgel is formed by having a polymerizable monomer on the surface thereof is particularly preferable from the viewpoint of image forming sensitivity and printing durability.
In order to obtain better on-press developability, the image recording layer is preferably a microcapsule type or microgel type image recording layer.

As a method of microencapsulating or microgelling the image recording layer constituents,
Known methods can be applied.

The average particle size of the microcapsules or microgel is preferably 0.01 to 3.0 μm. 0.05-2.0 micrometers is further more preferable, and 0.10-1.0 micrometer is especially preferable. Within this range, good resolution and stability over time can be obtained.

<2> Binder polymer In the image recording layer of the present invention, a binder polymer can be used in order to improve the film strength of the image recording layer. As the binder polymer that can be used in the present invention, conventionally known binder polymers can be used without limitation, and polymers having film properties are preferred. Examples of such binder polymers include acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, methacrylic resins, polystyrene resins, novolac phenolic resins, polyester resins, and synthetic rubbers. And natural rubber.
The binder polymer may have crosslinkability in order to improve the film strength of the image area. In order to impart crosslinkability to the binder polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may be introduced by copolymerization.
Examples of polymers having an ethylenically unsaturated bond in the main chain of the molecule include poly-1,4-
Examples thereof include butadiene and poly-1,4-isoprene.
Examples of polymers having an ethylenically unsaturated bond in the side chain of the molecule are polymers of esters or amides of acrylic acid or methacrylic acid where the ester or amide residue (R of -COOR or -CONHR) is Mention may be made of polymers having an ethylenically unsaturated bond.

Examples of residues having an ethylenically unsaturated bond (R above) include — (CH ₂ ) _n CR ¹ ═
^{CR 2 R 3, - (CH} 2 O) n CH 2 CR 1 = CR 2 R 3, - (CH 2 CH 2 O) n CH
^{_{2 CR 1 = CR 2 R 3}} , - (CH 2) n NH-CO-O-CH 2 CR 1 = CR 2 R 3, -
_{(CH 2) n -O-CO} -CR 1 = CR 2 R 3 and _{(CH 2 CH 2 O) 2} -X ( wherein,
R ^{1 to} R ³ each represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkoxy group or an aryloxy group, and R ¹ and R ² or R ³ are bonded to each other to form a ring. May be formed. n represents an integer of 1 to 10. X represents a dicyclopentadienyl residue. ).
Specific examples of the ester _{residue, -CH 2 CH = CH 2,} ( described in JP Kokoku _{7-21633.) - CH 2 CH 2} O-CH 2 CH = CH 2, -CH 2 C (CH ₃ )
_{= CH 2, -CH 2 CH =} CH-C 6 H 5, -CH 2 CH 2 OCOCH = CH-C 6 H 5
_{, -CH 2 CH 2 -NHCOO-CH} 2 CH = CH 2 and CH ₂ CH ₂ O-X (wherein,
X represents a dicyclopentadienyl residue. ).
Specific examples of the amide residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ —Y (wherein Y
Represents a cyclohexene residue. ), —CH ₂ CH ₂ —OCO—CH═CH ₂ .

For example, the binder polymer having a crosslinkable property has a free radical (
A polymerization initiation radical or a growth radical in the polymerization process of a polymerizable monomer) is added, and addition polymerization is performed directly between polymers or via a polymerization chain of the polymerizable monomer to form a crosslink between polymer molecules and cure. Alternatively, atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to the functional bridging group) are abstracted by free radicals to form polymer radicals that are bonded to each other so that crosslinking between the polymer molecules occurs. Forms and cures.

The content of the crosslinkable group in the binder polymer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 per 1 g of the binder polymer.
mmol, more preferably 1.0-7.0 mmol, most preferably 2.0-5.5 mm
ol. Within this range, good sensitivity and good storage stability can be obtained.

The content of the binder polymer is 5 to 90% by mass, preferably 5 to 80% by mass, and more preferably 10 to 70% by mass with respect to the total solid content of the image recording layer. Within this range, good image area strength and image formability can be obtained.
(C) The polymerizable monomer and the binder polymer are preferably used in an amount of 0.5 / 1 to 4/1 in terms of mass ratio.

<3> Surfactant In the image recording layer of the present invention, a surfactant can be used in order to promote on-press developability and improve the coated surface state. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorosurfactants. Surfactant may be used independently and may be used in combination of 2 or more type.

The nonionic surfactant used for this invention is not specifically limited, A conventionally well-known thing can be used. For example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol Fatty acid partial esters,
Propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylenated castor oil , Polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamine, triethanolamine fatty acid ester, trialkylamine oxide, polyethylene glycol, polyethylene And a copolymer of glycol and polypropylene glycol.

The anionic surfactant used in the present invention is not particularly limited, and conventionally known anionic surfactants can be used. For example, fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinate esters, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy poly Oxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, fatty acid alkyl esters Sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alcohols Ruphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, styrene / maleic anhydride Examples thereof include partial saponification products of polymers, partial saponification products of olefin / maleic anhydride copolymers, and naphthalene sulfonate formalin condensates.

The cationic surfactant used in the present invention is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.
The amphoteric surfactant used in the present invention is not particularly limited, and conventionally known amphoteric surfactants can be used. Examples thereof include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric acid esters, and imidazolines.

Of the above surfactants, the term “polyoxyethylene” can be read as “polyoxyalkylene” such as polyoxymethylene, polyoxypropylene, polyoxybutylene, etc. These surfactants can also be used.

More preferable surfactants include fluorine-based surfactants containing a perfluoroalkyl group in the molecule. Examples of such fluorosurfactants include anionic types such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and perfluoroalkyl phosphates; amphoteric types such as perfluoroalkyl betaines; Cation type such as trimethylammonium salt; perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct, oligomer containing perfluoroalkyl group and hydrophilic group, oligomer containing perfluoroalkyl group and lipophilic group, perfluoroalkyl Nonionic types such as an oligomer containing a group, a hydrophilic group and a lipophilic group, and a urethane containing a perfluoroalkyl group and a lipophilic group.
JP-A-62-170950, JP-A-62-226143, and JP-A-60-16814.
The fluorine-type surfactant described in each gazette of No. 4 is also mentioned suitably.

Surfactant can be used individually or in combination of 2 or more types.
The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 5% by mass with respect to the total solid content of the image recording layer.

<4> Colorant In the image recording layer of the present invention, a dye having a large absorption in the visible light region can be used as an image colorant. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603
, Oil Black BY, Oil Black BS, Oil Black T-505 (made by Orient Chemical Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI425)
55), methyl violet (CI42535), ethyl violet, rhodamine B (
CI145170B), malachite green (CI42000), methylene blue (CI
52015) and the like, and dyes described in JP-A-62-293247. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, titanium oxide, etc. can be suitably used.
When these colorants are used, it is easy to distinguish between an image area after image formation and a non-image area, so it is preferable to add them. The added amount is 0.01 to about the total solid content of the image recording material.
The ratio is 10% by mass.

<5> Print-out agent To the image-recording layer of the invention, a compound that changes color by an acid or a radical can be added in order to produce a print-out image. As such a compound, for example, various dyes such as diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminoquinone, azo, and azomethine are effectively used.

A suitable addition amount of the dye that changes color by an acid or radical is 0.01 to 10% by mass with respect to the solid content of the image recording layer.

<6> Polymerization inhibitor A small amount of a thermal polymerization inhibitor is added to the image recording layer of the present invention in order to prevent unnecessary thermal polymerization of the polymerizable monomer (C) during the production or storage of the image recording layer. It is preferable to do this.
Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, di-t-
Butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4
'-Thiobis (3-methyl-6-tert-butylphenol), 2,2'-methylenebis (4
-Methyl-6-t-butylphenol) and N-nitroso-N-phenylhydroxylamine aluminum salts are preferred. The addition amount of the thermal polymerization inhibitor is preferably about 0.01 to about 5% by mass with respect to the total solid content of the image recording layer.

<7> Higher fatty acid derivatives and the like In the image recording layer of the present invention, a higher fatty acid derivative such as behenic acid and behenic acid amide is added to prevent polymerization inhibition due to oxygen, and a drying process after coating. May be unevenly distributed on the surface of the image recording layer. The amount of the higher fatty acid derivative added is preferably about 0.1 to about 10% by mass with respect to the total solid content of the image recording layer.

<8> Plasticizer The image recording layer of the present invention may contain a plasticizer in order to improve the on-press developability.
Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate,
Phthalic acid esters such as dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diallyl phthalate; dimethyl glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, triethylene Glycol esters such as glycol dicaprylate; Phosphate esters such as tricresyl phosphate and triphenyl phosphate; Aliphatics such as diisobutyl adipate, dioctyl adipate, dimethyl sebacate, dibutyl sebacate, dioctyl azelate, dibutyl maleate Dibasic acid esters: polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, lauric acid Le can be preferably used.
The plasticizer content is preferably about 30% by mass or less based on the total solid content of the image recording layer.

<9> Inorganic fine particles The image recording layer of the present invention may contain inorganic fine particles in order to improve the cured film strength and on-press developability.
As the inorganic fine particles, for example, silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate or a mixture thereof can be preferably mentioned. These can be used for strengthening the film, enhancing interfacial adhesion by surface roughening, and the like.
The inorganic fine particles preferably have an average particle diameter of 5 nm to 10 μm, preferably 0.5 μm to 3 μm.
It is more preferable that Within the above range, it is possible to form a non-image portion having excellent hydrophilicity, which is stably dispersed in the image recording layer, sufficiently retains the film strength of the image recording layer, and hardly causes stains during printing.
The inorganic fine particles as described above can be easily obtained as a commercial product such as a colloidal silica dispersion.
The content of the inorganic fine particles is preferably 40% by mass or less, and more preferably 30% by mass or less, based on the total solid content of the image recording layer.

<10> Low molecular weight hydrophilic compound The image-recording layer of the invention may contain a hydrophilic low molecular weight compound in order to improve the on-press developability. Examples of hydrophilic low molecular weight compounds include water-soluble organic compounds such as glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol, and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, organic sulfonic acids such as alkylsulfonic acid, toluenesulfonic acid and benzenesulfonic acid and salts thereof, alkylsulfamic acid and the like Organic sulfamic acids and salts thereof, organic sulfuric acids and salts thereof such as alkyl sulfuric acid and alkyl ether sulfuric acid, organic phosphonic acids and salts thereof such as phenylphosphonic acid, Stone acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, organic carboxylic acids and salts thereof such as amino acids and the like.

The amount of these low molecular weight hydrophilic compounds added to the image recording layer is 0.5% of the total solid content of the image recording layer.
It is preferable that it is 20 mass% or less. More preferably, they are 1 mass% or more and 10 mass% or less, More preferably, they are 2 mass% or more and 8 mass% or less. In this range, good on-press developability and printing durability can be obtained.
These compounds may be used alone or in combination of two or more.

<11> Grease-sensitizing agent In the present invention, a phosphonium compound may be used in combination with the specific polymer of the present invention in order to improve the inking property. Phosphonium compounds are surface coating agents for inorganic layered compounds (
It functions as a sensitizing agent) and prevents deterioration of the inking property during printing by the inorganic layered compound. Suitable phosphonium compounds include phosphonium compounds described in JP-A-2006-297907 and compounds represented by the following general formula (VII).

In formula (VII), Ar _{1 to} Ar ₆ each independently represents an aryl group or a heterocyclic group, and L is 2
Represents a valent linking group, X ⁿ⁻ represents an n-valent counter anion, n represents an integer of 1 to 3,
m represents a number satisfying nxm = 2.

Here, as the aryl group, phenyl group, naphthyl group, tolyl group, xylyl group, fluorophenyl group, chlorophenyl group, bromophenyl group, methoxyphenyl group, ethoxyphenyl group, dimethoxyphenyl group, methoxycarbonylphenyl group, dimethylaminophenyl A group and the like are preferable. Examples of the heterocyclic group include a pyridyl group, a quinolyl group, a pyrimidinyl group, a thienyl group, and a furyl group. L is preferably a linking group having 6 to 15 carbon atoms, more preferably a linking group having 6 to 12 carbon atoms.

Preferable examples of X ⁿ⁻ include halogen anions such as Cl ⁻ , Br ⁻ and I ⁻ , sulfonate anions, carboxylate anions, sulfate anions, PF ₆ ⁻ , BF ₄ ⁻ and perchlorate anions. . Of these, halogen anions such as Cl ⁻ , Br ⁻ and I ⁻ , sulfonate anions, and carboxylate anions are particularly preferable.

The amount of the phosphonium compound added to the image recording layer is 0.01 to 2% of the solid content of the image recording layer.
0 mass% is preferable, 0.05-10 mass% is further more preferable, and 0.1-5 mass% is the most preferable. Within these ranges, good ink fillability during printing can be obtained.

  The present sensitizer can be added not only to the image recording layer but also to the protective layer.

<12> Co-sensitizer In the image recording layer of the present invention, a known compound called a co-sensitizer or a chain transfer agent having an action such as further improving sensitivity or suppressing polymerization inhibition by oxygen is contained. May be added. In the case of a lithographic printing plate precursor for blue laser light having a wavelength of 360 nm to 450 nm, which is particularly required to have high sensitivity, it is preferable to use a cosensitizer.

Examples of such compounds include amines such as “Journal of Polym” by MR Sander et al.
er Society ”10: 3173 (1972), Japanese Examined Patent Publication No. 44-20189, Japanese Patent Laid-Open No. 51
-82102, JP-A-52-134692, JP-A-59-138205, JP-A-6
0-84305, JP-A 62-18537, JP-A 64-33104, Research D
isclosure 33825, and the like. Specifically, triethanolamine, p-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-
And methylthiodimethylaniline.

As another example of acting as a chain transfer agent, for example, SH, PH, SiH, G in the molecule
The compound group which has eH is mentioned. These can donate hydrogen to low-activity radical species to generate radicals, or can be oxidized and then deprotonated to generate radicals.

The amount of these co-sensitizers used is preferably 0.01 with respect to the total solid content of the image recording layer.
-20% by mass, more preferably 0.1-15% by mass. More preferably 1.0-1
0% by mass.

<Formation of image recording layer>
The image recording layer of the present invention is applied by preparing a coating solution by dispersing or dissolving each of the necessary components in a solvent. Examples of the solvent used here 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,
Examples thereof include N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyl lactone, toluene, water, and the like, but are not limited thereto. These solvents are
Used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The image recording layer of the present invention can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeating a plurality of coatings and dryings.

Further, the coating amount (solid content) of the image recording layer on the support obtained after coating and drying varies depending on the use, but generally 0.3 to 3.0 g / m ² is preferable. Within this range, good sensitivity and good film properties of the image recording layer can be obtained.
Various methods can be used as the coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

[Support]
The support used for the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, plastic (eg, polyethylene, polypropylene,
Paper, metal plates (eg, aluminum, zinc, copper, etc.)
, Plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.) Alternatively, vapor-deposited paper or plastic film can be used. Preferable supports include a polyester film and an aluminum plate. Among these, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable.

The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of different elements, or a plastic laminated on a thin film of aluminum or an aluminum alloy. 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 preferably 10% by mass or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in the refining technology.
It may contain a slightly different element. The composition of the aluminum plate is not specified, and a publicly known material can be used as appropriate.

The thickness of the support is preferably from 0.1 to 0.6 mm, more preferably from 0.15 to 0.4 mm.

[Lithographic printing method]
The lithographic printing plate precursor of the present invention is subjected to on-press development by supplying printing ink and fountain solution after exposure and without being subjected to a development processing step. And then used for printing. Hereinafter, the printing method of the present invention will be described in detail.

〔exposure〕
In the present invention, a laser is preferable as a light source used for imagewise exposure. Although the laser used for this invention is not specifically limited, The solid laser and semiconductor laser which irradiate infrared rays with a wavelength of 760-1200 nm, the semiconductor laser etc. which irradiate 250-420 nm light etc. are mentioned suitably.
With respect to the infrared laser, the output is preferably 100 mW or more, the exposure time per pixel is preferably within 20 microseconds, and the irradiation energy amount is 10 to 10.
It is preferably 300 mJ / cm ² . In a semiconductor laser that emits light of 250 to 420 nm, the output is preferably 0.1 mW or more. In any laser, it is preferable to use a multi-beam laser device in order to shorten the exposure time.

[On-machine development]
The exposed lithographic printing plate precursor is mounted on a plate cylinder of a printing machine. In the case of a printing press equipped with a laser exposure device, imagewise exposure is performed after a lithographic printing plate precursor is mounted on a plate cylinder of the printing press.

After the lithographic printing plate precursor is exposed imagewise with an infrared laser or the like, printing is performed by supplying printing ink and fountain solution without going through a development process such as a wet development process, and the like in the exposed part of the image recording layer. The image recording layer cured by exposure forms a printing ink receiving portion having an oleophilic surface. On the other hand, in the unexposed area, the uncured image recording layer is removed by dissolution or dispersion by the supplied dampening water and / or printing ink, and a hydrophilic surface is exposed in that area. As a result, the fountain solution adheres to the exposed hydrophilic surface, and the printing ink is deposited on the image recording layer in the exposed area and printing is started.

Here, dampening water or printing ink may be supplied to the printing plate first, but the dampening water is prevented from being contaminated by the components of the image recording layer from which the dampening water has been removed. It is preferable to supply printing ink. As the fountain solution and printing ink, normal lithographic fountain solution and printing ink are used.
In this way, the lithographic printing plate precursor is subjected to on-press development on an offset printing machine and used as it is for printing a large number of sheets.

In the case where the lithographic printing plate precursor of the present invention is not capable of on-machine development as described above and requires a development processing step such as a wet development processing step, the exposure step and the printing step described above are performed. In the meantime, development processing is performed.
The development processing applied to the present invention is determined by the image recording layer, but the lithographic printing plate precursor of the present invention is preferably subjected to the development processing shown below.

[Development processing]
The developer suitably used in the present invention is an aqueous solution having a pH of 2 to 10. For example,
Water alone or an aqueous solution containing water as a main component (containing 60% by mass or more of water) is preferable, and in particular, an aqueous solution having the same composition as a generally known fountain solution, a surfactant (anionic, nonionic, cationic) Etc.) and aqueous solutions containing water-soluble polymer compounds are preferred. In particular,
An aqueous solution containing both a surfactant and a water-soluble polymer compound is preferred. The pH of the developer is
More preferably, the acidity is 3 to 8, more preferably 4 to 6.9.

  Known techniques described in JP-A-2007-50660, JP-A-2008-191468, and the like can be appropriately applied to the support of the planographic printing plate precursor of the present invention and other matters related to the planographic printing plate precursor.

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

〔Example〕
(Synthesis of Intermediate Monomer (1))

361.58 g (2.3 mol) of N, N-dimethylaminoethyl methacrylate, 0.1647 g of p-methoxyphenol and 1150 ml of acetonitrile were mixed and stirred at room temperature. Subsequently, n-butyl tosylate (525.11 g: 2.3 mol) was added dropwise over 30 minutes. The mixture was stirred at 80 ° C. for 8 hours and then allowed to cool. The reaction solution was dropped into a solution obtained by dissolving 846.68 g of KPF _{6 in} 12.6 L of water to obtain white crystals. The mixture was further stirred for 30 minutes, filtered, and washed with 5 L of water. Further, after washing in 5 L of water and filtering, the resulting crystals were washed with 3 L of ethyl acetate / hexane = 50/50 (vol.) And then filtered to obtain 1 L of ethyl acetate / hexane = 50/50 (vol.). And then dried after washing. It dried under reduced pressure at room temperature and obtained 561.4g of intermediate monomers (1) of the white powder.

  In a 500 ml four-necked flask equipped with a cooling bowl and stirring blades (rotation speed 250 rpm), 77.43 g of a mixed solution of methyl ethyl ketone (MEK): methoxypropylene glycol (MFG) = 1: 1, Blemmer PME100 (NOF Co., Ltd.) (Manufactured) 45.17 g was added and the internal temperature was set to 70 ° C. Monomer solution consisting of 51.26 g of the above intermediate monomer (1), methyl ethyl ketone: methoxypropylene glycol = 1: 1 mixed solution 51.26 g and 0.691 g of V-601F (radical polymerization initiator manufactured by Wako Pure Chemical Industries), methyl ethyl ketone: methoxypropylene glycol A radical polymerization initiator solution consisting of 17.94 g of a mixed solution of = 1: 1 was prepared. The monomer solution was added dropwise to the reaction vessel at 1.6 ml / min for 30 minutes, 0.33 ml / min for 90 minutes, and 0.13 ml / min for 180 minutes while changing the dropping speed in three stages. Further, the radical polymerization initiator solution was dropped at a constant rate of 0.33 ml / min from the start to the end of dropping of the monomer solution. After completion of the monomer solution dropping, stirring was continued for 2 hours, and then the initiator solution was added dropwise at a constant rate of 40 ml / min so that the amount of V-601F was 1.36 g. Next, immediately after the addition of the initiator, the temperature was raised to 90 ° C., and stirring was continued for 2 hours, followed by cooling to obtain a polymer solution. The reduced specific viscosity was 60.6 and the solid content concentration was 31.7% by mass.

[Comparative Example]
150 g of a mixed solution of methyl ethyl ketone: methoxypropylene glycol = 1: 1 was placed in a 500 ml four-necked flask equipped with a cooling pad and a stirring blade (rotation speed: 250 rpm), and the internal temperature was set to 70.degree. Monomer solution consisting of 42.50 g of the above intermediate monomer (1), 89.67 g of Bremer PME100, 100 g of methyl ethyl ketone: methoxypropylene glycol = 1: 1, and 1.36 g of V-601F, 1.36 g of methyl ethyl ketone: methoxypropylene glycol = 1: 1 A radical polymerization initiator solution consisting of 35 g of the solution was prepared. The monomer solution was added dropwise at a constant rate of 1.93 ml / min over 2 hours. Further, the radical polymerization initiator solution was dropped at a constant rate of 0.33 ml / min from the start to the end of dropping of the monomer solution. After completion of the monomer solution dropping, stirring was continued for 2 hours, and then the initiator solution was added dropwise at a constant rate of 40 ml / min so that the amount of V-601F was 1.36 g. Next, immediately after the addition of the initiator, the temperature was raised to 90 ° C., and stirring was continued for 2 hours, followed by cooling to obtain a polymer solution. The reduced specific viscosity was 58.2 and the solid content concentration was 30.4% by mass.

[Reference Example] (Synthesis with NMP solvent)
150 g of N-methylpyrrolidone (NMP) was placed in a 500 ml four-necked flask equipped with a cooling pad and a stirring blade (rotation speed: 250 rpm), and the internal temperature was adjusted to 70 ° C. A monomer solution consisting of 42.50 g of the intermediate monomer (1), 89.67 g of Blemmer PME100, and 100 g of NMP and a radical polymerization initiator solution consisting of 1.36 g of V-601F and 35 g of NMP were prepared. The monomer solution was added dropwise at a constant rate of 0.33 ml / min over 2 hours. The radical polymerization initiator solution was added dropwise at a constant rate of 1.93 ml / min from the start to the end of the addition of the monomer solution. After completion of the monomer solution dropping, stirring was continued for 2 hours, and then the initiator solution was added dropwise at a constant rate of 40 ml / min so that the amount of V-601F was 1.36 g. Next, immediately after the addition of the initiator, the temperature was raised to 90 ° C., and stirring was continued for 2 hours, followed by cooling to obtain a polymer solution. The reduced specific viscosity was 61.8, and the solid content concentration was 30.5% by mass.

  A lithographic printing plate precursor was prepared using each polymer (specific polymer) obtained by each of the production methods of the above Examples, Comparative Examples, and Reference Examples, and its characteristics were evaluated.

[Preparation of lithographic printing plate precursor (on-press development type)]

(1) Production of support 1 In order to remove the rolling oil on the surface of a 0.3 mm thick aluminum plate (material 1050), degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution. Thereafter, the aluminum surface was grained using three bundle-planted nylon brushes having a bristle diameter of 0.3 mm and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm, and washed thoroughly with water. This plate was etched by being immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C for 9 seconds, washed with water, further immersed in 20 mass% nitric acid at 60 ° C for 20 seconds, and washed with water. The etching amount of the grained surface at this time was about 3 g / m ² .
Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass aqueous nitric acid solution (containing 0.5% by mass aluminum ions), and the liquid temperature was 50 ° C. Time TP until the current value reaches the peak from zero as the AC power supply waveform
Was subjected to electrochemical surface roughening treatment using a trapezoidal rectangular wave alternating current with a duty ratio of 1: 1 and a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. The amount of electricity in the nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode. Then, water washing by spraying was performed.

Next, a 0.5 mass% hydrochloric acid aqueous solution (containing 0.5 mass% aluminum ions), a liquid temperature of 50
An electrolytic surface roughening treatment was performed in the same manner as in nitric acid electrolysis under the conditions of an electrolytic amount of 50 ° C./dm ² when the aluminum plate was an anode when the aluminum plate was an anode, and then washed with water by spraying. .
This plate was provided with a DC anodized film of 2.5 g / m ² at a current density of 15 A / dm ² using 15% by mass sulfuric acid (containing 0.5% by mass of aluminum ions) as an electrolyte, then washed with water and dried. A support 1 was prepared. The center line average roughness (Ra) of the support 1 was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.
Furthermore, the following undercoat liquid (1) was applied and dried at 100 ° C. for 3 minutes. The dry coating amount is 6m
g / m ² .

-Undercoat liquid (1)-
・ Undercoat compound (1) (Mw: 60,000) 0.017 g
・ Methanol 9.00 g
・ Water 1.00g

(2) Formation of Image Recording Layer and Protective Layer An image recording layer coating solution 1 having the following composition was bar-coated on the support on which the undercoat layer had been formed, followed by oven drying at 100 ° C. for 60 seconds, and a dry coating amount of 1 An image recording layer of 0.0 g / m ² was formed. Subsequently, a protective layer coating solution 1 having the following composition was bar coated on the image recording layer,
The lithographic printing plate precursor (1) was obtained by oven drying in 60 seconds to form a protective layer having a dry coating amount of 0.160 g / m ² .
The image recording layer coating solution 1 was obtained by mixing and stirring the following photosensitive solution and microgel solution immediately before coating.

-Sensitive solution-
Binder polymer (1) 0.177g
(B) Polymerization initiator (the following compound I-28) 0.142 g
(A) Infrared absorber (1) 0.0308 g
(C) Polymerizable monomer (Aronix M-215 (manufactured by Toa Gosei Co., Ltd.)) 0.319 g
0.05g of specific polymers listed in Table 1
Fluorosurfactant (1) 0.004g
Ionic surfactant 0.125g
(Pionine A-24-EA (Takemoto Yushi Co., Ltd., 40% by mass aqueous solution)
Methyl ethyl ketone 2.554g
1-methoxy-2-propanol 7.023 g

-Microgel solution-
Microgel dispersion (1) 1.800 g
1.678 g of water

In addition, the synthesis | combining method of the specific polymer used for the said photosensitive liquid, the synthesis | combination of the microgel dispersion liquid (1) used for a microgel liquid, and the structure of another compound are shown below.

-Synthesis of microgel dispersion (1)-
As an oil phase component, trimethylolpropane and xylene diisocyanate adduct (manufactured by Mitsui Takeda Chemical Co., Ltd., Takenate D-110N, 75% by mass ethyl acetate solution) 10.0 g
As a polymerizable monomer, 6.00 g of Aronix M-215 (manufactured by Toa Gosei Co., Ltd.) and 0.12 g of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in 16.67 g of ethyl acetate. As an aqueous phase component, 37.5 g of a 4 mass% aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12,000 rpm using a homogenizer.
The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 2 hours. The microgel dispersion thus obtained was diluted with distilled water so that the solid content concentration was 21% by mass to obtain a microgel dispersion (1). The average particle size was 0.23 μm.

−Protective layer coating solution 1−
-1.5 g of the following layered compound dispersion (1)
・ Polyvinyl alcohol 0.06g
(PVA105, manufactured by Kuraray Co., Ltd., saponification degree 98.5 mol%, polymerization degree 500)
・ Polyvinylpyrrolidone 0.01g
(Polyvinylpyrrolidone K30, manufactured by Tokyo Chemical Industry Co., Ltd., Mw = 40,000)
・ Vinyl pyrrolidone / vinyl acetate copolymer 0.01g
(LUVITEC VA64W, manufactured by ISP, copolymerization ratio = 6/4)
・ Nonionic surfactant 0.013g
(Emalex 710, manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 6.0g

-Preparation of layered compound dispersion (1)-
Synthetic mica Somasif ME-100 (manufactured by Coop Chemical Co., Ltd.) is added at a ratio of 6.4 g to 193.6 g of ion-exchanged water, and the average particle diameter (laser scattering method) is 3 μm using a homogenizer. Dispersed. The aspect ratio of the obtained dispersed inorganic particles was 100 or more.

[Evaluation of planographic printing plate precursor]
Each of the obtained lithographic printing plate precursors was exposed with a Trend setter 3244VX manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser under the conditions of an output of 11.7 W, an outer drum rotational speed of 250 rpm, and a resolution of 2400 dpi. The upper developability, the wall-thickness and the printing durability were evaluated. The results are shown in Table 1.

(Evaluation of on-press developability)
Without developing the exposed lithographic printing plate precursor, the Heidelberg printing press SOR
Attached to the cylinder of -M, dampening water (EU-3 (Effect manufactured by FUJIFILM Corporation) / water / isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink ( After supplying fountain solution and ink using Dainippon Ink & Chemicals, Inc.
Printing was performed at a printing speed of 000 sheets. At this time, the number of print sheets required until the ink was not transferred to the unexposed portion (non-image portion) of the image recording layer was evaluated as on-press developability.
The smaller the number, the better the on-press developability.

(Evaluation of inking properties)
As the number of printed sheets is increased, the ink receptivity of the image recording layer gradually decreases, so that the ink density on the printing paper decreases. The ink density (reflection density) is less than that at the start of printing.
The number of printed sheets when 01 decreased was evaluated as the inking property. It is evaluated that the larger the number, the better the inking property.

(Evaluation of printing durability)
When printing is continued and the number of printed sheets is increased, the image recording layer is gradually worn and the ink acceptability is lowered, so that the ink density on the printing paper is lowered. Printing durability was evaluated by the number of printed sheets when the ink density (reflection density) was reduced by 0.1 from the start of printing. The larger the number of sheets, the better the printing durability.

  As is apparent from Table 1, the lithographic printing plate precursor using the polymer obtained by the production method of the example is a lithographic printing plate using the polymer obtained by the production method of the reference example using NMP as a polymerization solvent. It had the same characteristics as the original. On the other hand, the lithographic printing plate precursor using the polymer obtained by the production method of the comparative example is compared with each lithographic printing plate precursor using the polymer obtained by the production method of Examples and Reference Examples, The characteristics were inferior.

Claims (8)

A method for producing a polymer by polymerizing a quaternary ammonium salt monomer represented by the following general formula (1) and a monomer represented by the following general formula (2), which is represented by the following general formula (2): A method for producing a polymer, wherein a solution in which a quaternary ammonium salt monomer represented by the following general formula (1) is dissolved is dropped into a solution in which the monomer is dissolved, and the dropping speed is changed at least once .

(In General Formula (1), R ¹¹ represents a hydrogen atom, an alkyl group, or a halogen atom. L ¹ represents a single bond or a divalent linking group, and R ¹² , R ^13, and R ¹⁴ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, or .R ¹² representing an alkylidene group, at least two selected from R ¹³ and R ¹⁴ may be bonded to form a ring together, .X ^- is This represents a counter ion necessary for neutralizing the charge, wherein R ²¹ represents a hydrogen atom, an alkyl group, or a halogen atom, and R ²² represents an ester group, an amide group, a cyano group, or a hydroxy group. Or an aryl group.)   The method for producing a polymer according to claim 1, wherein when the dropping speed is changed, the dropping speed is changed.   The solvent for dissolving the monomer is a mixed solvent of a ketone solvent and an alcohol solvent, and the ratio thereof is ketone solvent: alcohol solvent = 70: 30 to 30:70. A process for producing the polymer described in 1. In the general formula (1), method for producing a polymer according to claim 1 in which L ^1, characterized in that at least a group having a group selected from a phenylene group, a carbonyl group and carbonyl imino group. In the general formula (1), X ⁻ is at least 1 selected from halide ion, carboxylate ion, alkylsulfonate ion, alkylphosphate ion, phosphonate ion, arylsulfonate ion, PF ₆ ^— and BF ₄ ^—. The method for producing a polymer according to claim 1, wherein the polymer is a seed. In the general formula (2), the method of producing polymer according to claim 1, wherein R ²² is an ester group, an amide group or a phenyl group which may have a substituent. In the general formula (2), method for producing a polymer according to claim 1, wherein R ²² is a group containing a polyalkylene group. A lithographic printing plate precursor polymer produced by polymerizing a quaternary ammonium salt monomer represented by the following general formula (1) and a monomer represented by the following general formula (2), the polymer having the following general formula (2 ) Is dissolved in a solution in which the monomer represented by formula (1) is dissolved, and the dropping speed is changed at least once. A polymer for a lithographic printing plate precursor characterized by the above.

(In General Formula (1), R ¹¹ represents a hydrogen atom, an alkyl group, or a halogen atom. L ¹ represents a single bond or a divalent linking group, and R ¹² , R ^13, and R ¹⁴ are each independently a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, or .R ¹² representing an alkylidene group, at least two selected from R ¹³ and R ¹⁴ may be bonded to form a ring together, .X ^- is This represents a counter ion necessary for neutralizing the charge, wherein R ²¹ represents a hydrogen atom, an alkyl group, or a halogen atom, and R ²² represents an ester group, an amide group, a cyano group, or a hydroxy group. Or an aryl group.)