JP2007316598A - Lithographic printing plate original and method for preparation of lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithographic printing plate original which is developable with an aqueous developer having pH of 2.0-10.0 and excels in printing durability. <P>SOLUTION: The lithographic printing plate original having a photosensitive layer on a support is used in a system comprising: imagewise exposing the lithographic printing plate original with a laser beam of 350-450 nm; and rubbing a surface of the exposed lithographic printing plate original with a rubbing member in a presence of a developer having pH of 2-10 in an automatic processor equipped with the rubbing member to remove an unexposed area of the photosensitive layer, wherein the photosensitive layer comprises a photosensitive resin composition containing (A) a sensitizing dye absorbing light of 350-450 nm, (B) a polymerization initiator, (C) a polymerizable compound and (D) a binder polymer, and (D) the binder polymer is a specific acrylic resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a planographic printing plate precursor and a method for producing a planographic printing plate.

In general, a lithographic printing plate has a surface composed of an oleophilic image portion and a hydrophilic non-image portion. In lithographic printing, dampening water and oil-based ink are alternately applied to the plate surface, and the hydrophilic non-image area is dampened with a dampening water receiving area (ink non-receiving area) by utilizing the property that water and oil repel each other. ), After the ink is received only in the oleophilic image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive 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. The lithographic printing plate is obtained by carrying out plate making by a method in which the surface of the hydrophilic support is exposed by dissolving and removing to form a non-image portion.

  In the conventional plate making process of a lithographic printing plate precursor, a step of dissolving and removing unnecessary image recording layers with a developer or the like is necessary after exposure, but simplifies such additional wet processing. This is one of the issues. As one of simplification, it is desired that development can be performed with an aqueous solution close to neutrality or simple water.

  On the other hand, in recent years, digitization technology that electronically processes, stores, and outputs image information using a computer has become widespread, and various new image output methods corresponding to such digitization technology have been put into practical use. It has come to be. 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 technology for manufacturing is attracting attention. Accordingly, obtaining a lithographic printing plate precursor adapted to such a technique is one of the important technical issues.

  From the background as described above, it is now more strongly desired than ever to adapt both the simplification of the plate making operation and the digitization.

On the other hand, for example, in Patent Document 1, in an image forming layer of a lithographic printing plate precursor having an image forming layer containing a hydrophobic precursor, a hydrophilic resin, and a photothermal conversion agent on a hydrophilic support. In addition to on-press development, it can be used for printing after being exposed to a liquid development treatment using water or a suitable aqueous solution as a developer, by containing a compound having an ethylene oxide chain. ing.

Patent Document 2 contains (i) a hydrophilic support, and (ii) a radical polymerizable ethylenically unsaturated monomer, a radical polymerization initiator and an infrared absorbing dye, and is cured by infrared laser exposure. Moreover, a lithographic printing plate precursor comprising an oleophilic heat-sensitive layer containing 60% by mass or more of water and developable with an aqueous developer having a pH of 2.0 to 10.0 is prepared and exposed imagewise with an infrared laser. A processing method for a lithographic printing plate precursor comprising removing an uncured region of the heat-sensitive layer with an aqueous developer is described.
JP 2002-365789 A US Patent Application Publication No. 2004/0013968

  However, in order to maintain developability with respect to an aqueous developer having a pH of 2.0 to 10.0, the photosensitive layer of the lithographic printing plate precursor needs to be hydrophilic or highly water-permeable, but is cured by exposure. The resulting photosensitive layer lacked water resistance and film strength, and the resulting lithographic printing plate had insufficient printing durability. Accordingly, an object of the present invention is to provide a lithographic printing plate precursor which can be developed with an aqueous developer having a pH of 2.0 to 10.0 and provides a lithographic printing plate having excellent printing durability. Another object of the present invention is to provide a lithographic printing plate precursor having high sensitivity and excellent safelight suitability. Furthermore, it is providing the production method of the lithographic printing plate which uses this lithographic printing plate precursor.

The present inventor has found that the above problem can be solved by using a specific acrylic resin having an acid value of 0.3 meq / g or less as a binder polymer in the photosensitive layer.
That is, the present invention is as follows.

(1) An image is exposed to a lithographic printing plate precursor having a photosensitive layer on a support with a 350 to 450 nm laser, and then in the presence of a developer having a pH of 2 to 10 by an automatic processor equipped with a rubbing member. In the lithographic printing original plate in which the photosensitive layer in the non-exposed area is removed by rubbing the plate surface with a rubbing member, the photosensitive layer is (A) a sensitizing dye that absorbs 350 to 450 nm light, and (B) polymerization. It comprises a photosensitive resin composition containing an initiator, (C) a polymerizable compound, and (D) a binder polymer, wherein the (D) binder polymer has a hydrophilic group and a crosslinkable group with an acid value of 0.3 meq / A lithographic printing plate precursor characterized by being an acrylic resin of g or less.
(2) In the presence of a developer having a pH of 2 to 10 by an automatic processor equipped with a rubbing member after image exposure with a 350 to 450 nm laser on a lithographic printing plate precursor having a photosensitive layer on a support. In the lithographic printing original plate in which the photosensitive layer in the non-exposed area is removed by rubbing the plate surface with a rubbing member, the photosensitive layer is (A) a sensitizing dye that absorbs 350 to 450 nm light, and (B) polymerization. It comprises a photosensitive resin composition containing an initiator, (C) a polymerizable compound, and (D) a binder polymer, and the (D) binder polymer has an SP value of 19.0 to 21.5 (MPa) ^{1 / 2.} A lithographic printing plate precursor comprising an acrylic resin having an acid value of 0.3 meq / g or less.
(3) The lithographic printing plate precursor as described in (2), wherein the acrylic resin has a hydrophilic group and a crosslinkable group.
(4) The lithographic printing plate precursor as described in (1) or (3), wherein the acrylic resin contains a polymer unit having a hydrophilic group and a crosslinkable group.
(5) The lithographic printing plate precursor as described in (4), wherein the crosslinkable group is an ethylenically unsaturated bond group.
(6) The lithographic printing plate precursor as described in (5), wherein the ethylenically unsaturated bond group is an allyl group or a methacryloyl group.
(7) The lithographic printing plate precursor as described in any one of (1) to (6), wherein a protective layer is provided on the photosensitive layer.
(8) The lithographic printing plate precursor as described in any one of (1) to (7), wherein some or all of the components contained in the photosensitive layer are encapsulated in microcapsules.
(9) The lithographic printing plate precursor as described in any one of (1) to (8), wherein the polymerization initiator (B) is a hexaarylbiimidazole compound.
(10) The lithographic printing plate precursor as described in any one of (1) to (9), wherein the photosensitive layer further contains (E) a chain transfer agent.
(11) The lithographic printing plate precursor as described in (10), wherein the chain transfer agent (E) is a thiol compound represented by the following general formula (I).

（ここで、Ｒは置換基を有してもよいアルキル基または置換基を有してもよいアリール基を表し、ＡはＮ＝Ｃ−Ｎ部分と共に炭素原子を有する５員環または６員環のヘテロ環を形成する原子団を表し、Ａはさらに置換基を有してもよい。）
（１２） 上記（Ｃ）重合性化合物及び（Ｄ）バインダーポリマーの合計含有量が、上記感光層の全成分に対して、８０質量％以下であることを特徴とする（１）〜（１１）のいずれか一項に記載の平版印刷版原版。
（１３） 上記支持体と上記感光層の間に下塗り層を有し、該下塗り層が架橋性基を有する高分子化合物を含有することを特徴とする（１）〜（１２）のいずれか一項に記載の平版印刷版原版。
（１４） 支持体上に、 (Ａ)３５０〜４５０ｎｍの光を吸収する増感色素、(Ｂ)重合開始剤、(Ｃ)重合性化合物、及び(Ｄ) 親水性基及び架橋性基を有する酸価が０.３ｍｅｑ/ｇ以下のアクリル樹脂であるバインダーポリマーを含有する感光層を有する平版印刷版原版を、３５０〜４５０ｎｍのレーザーで画像露光した後、擦り部材を備えた自動処理機により、ｐＨが２〜１０の現像液の存在下、擦り部材で版面を擦ることにより、非露光部の感光層を除去することを特徴とする平版印刷版の作製方法。
（１５） 支持体上に、 (Ａ)３５０〜４５０ｎｍの光を吸収する増感色素、(Ｂ)重合開始剤、(Ｃ)重合性化合物、及び(Ｄ) ＳＰ値が１９．０〜２１．５（ＭＰａ）^１／２、且つ、酸価が０．３ｍｅｑ／ｇ以下のアクリル樹脂であるバインダーポリマーを含有する感光層を有する平版印刷版原版を、３５０〜４５０ｎｍのレーザーで画像露光した後、擦り部材を備えた自動処理機により、ｐＨが２〜１０の現像液の存在下、擦り部材で版面を擦ることにより、非露光部の感光層を除去することを特徴とする平版印刷版の作製方法。
（１６） 上記現像液のｐＨが３〜８であることを特徴とする（１４）又は（１５）に記載の平版印刷版の作製方法。
（１７） 上記擦り部材が、少なくとも２本の回転ブラシロールであることを特徴とする（１４）〜（１６）のいずれか一項に記載の平版印刷版の作製方法。
（１８） 露光から現像までの間に、さらに、露光された平版印刷版原版を加熱処理することを特徴とする（１４）〜（１７）のいずれか一項に記載の平版印刷版の作製方法。

Wherein R represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and A represents a 5-membered or 6-membered ring having a carbon atom together with an N═C—N moiety. (A) may further have a substituent.
(12) The total content of the polymerizable compound (C) and the binder polymer (D) is 80% by mass or less based on all components of the photosensitive layer (1) to (11) The lithographic printing plate precursor as described in any one of the above.
(13) Any one of (1) to (12), wherein an undercoat layer is provided between the support and the photosensitive layer, and the undercoat layer contains a polymer compound having a crosslinkable group. The lithographic printing plate precursor as described in the paragraph.
(14) On the support, (A) a sensitizing dye that absorbs light of 350 to 450 nm, (B) a polymerization initiator, (C) a polymerizable compound, and (D) a hydrophilic group and a crosslinkable group A lithographic printing plate precursor having a photosensitive layer containing a binder polymer which is an acrylic resin having an acid value of 0.3 meq / g or less is image-exposed with a laser of 350 to 450 nm, and then an automatic processor equipped with a rubbing member, A method for preparing a lithographic printing plate, comprising removing a photosensitive layer in an unexposed area by rubbing the plate surface with a rubbing member in the presence of a developer having a pH of 2 to 10.
(15) On the support, (A) a sensitizing dye that absorbs light of 350 to 450 nm, (B) a polymerization initiator, (C) a polymerizable compound, and (D) an SP value of 19.0 to 21. A lithographic printing plate precursor having a photosensitive layer containing a binder polymer that is an acrylic resin having an acid value of 5 (MPa) ^1/2 and an acid value of 0.3 meq / g or less was image-exposed with a 350 to 450 nm laser, Preparation of a lithographic printing plate characterized in that the photosensitive layer in the non-exposed area is removed by rubbing the plate surface with a rubbing member in the presence of a developer having a pH of 2 to 10 by an automatic processor equipped with a rubbing member Method.
(16) The method of preparing a lithographic printing plate as described in (14) or (15), wherein the pH of the developer is from 3 to 8.
(17) The method for producing a lithographic printing plate as described in any one of (14) to (16), wherein the rubbing member is at least two rotating brush rolls.
(18) The method for preparing a lithographic printing plate as described in any one of (14) to (17), wherein the exposed lithographic printing plate precursor is further subjected to heat treatment between exposure and development. .

  According to the present invention, it is possible to provide a lithographic printing plate precursor that can be developed with an aqueous developer having a pH of 2.0 to 10.0 and that provides a lithographic printing plate having excellent printing durability. Further, a method for producing a lithographic printing plate using this lithographic printing plate precursor can be provided.

[Lithographic printing plate precursor]
First, a planographic printing plate precursor according to the present invention will be described. The lithographic printing plate precursor according to the present invention is subjected to image exposure with a 350 to 450 nm laser, and then rubbed with a rubbing member in the presence of a developer having a pH of 2 to 10 by an automatic processor equipped with a rubbing member. Thus, the lithographic printing plate precursor is of a type that removes the photosensitive layer in the non-exposed area, and has a photosensitive layer on the support.

<Photosensitive layer>
The photosensitive layer of the lithographic printing plate precursor according to the invention contains (A) a sensitizing dye that absorbs light of 350 to 450 nm, (B) a polymerization initiator, (C) a polymerizable compound, and (D) a binder polymer. The binder polymer is an acrylic resin having a hydrophilic group and a crosslinkable group and an acid value of 0.3 meq / g or less, or an SP value of 19.0 to 21.5 (MPa) ^1/2 And an acrylic resin having an acid value of 0.3 meq / g or less. The photosensitive layer of the present invention can further contain other components as required. Hereinafter, the components of the photosensitive layer will be described in detail.

(A) Sensitizing dye The photosensitive layer of the present invention contains a sensitizing dye corresponding to the wavelength of the exposure light source.
First, a sensitizing dye that absorbs light of 350 to 450 nm will be described. The sensitizing dye that absorbs light of 350 to 450 nm preferably has a maximum absorption in the wavelength region of 350 to 450 nm. Examples of such a sensitizing dye include merocyanine dyes represented by the following general formula (V), benzopyrans and coumarins represented by the following general formula (VI), and fragrances represented by the following general formula (VII). And anthracenes represented by the following general formula (VIII).

(In the formula, A represents an S atom or NR ₆ , R ₆ represents a monovalent non-metallic atomic group, Y represents a basic nucleus of the dye in cooperation with the adjacent A and the adjacent carbon atom. A non-metallic atomic group, X ₁ and X ₂ each independently represent a monovalent non-metallic atomic group, and X ₁ and X ₂ may combine with each other to form an acidic nucleus of the dye.)

(In the formula, = Z represents an oxy group, a thioxy group, an imino group or an alkylidene group represented by the partial structural formula (1 ′), and X ₁ and X ₂ have the same meanings as those in the general formula (V); R _{7 to} R ₁₂ each independently represents a monovalent nonmetallic atomic group.)

(In the formula, Ar ₃ represents an aromatic group or a heteroaromatic group which may have a substituent, and R ₁₃ represents a monovalent nonmetallic atomic group. More preferable R ₁₃ represents an aromatic group or It is a heteroaromatic group, and Ar ₃ and R ₁₃ may be bonded to each other to form a ring.)

(In the formula, X ₃ , X ₄ and R _{14 to} R ₂₁ each independently represents a monovalent nonmetallic atomic group, and more preferable X ₃ and X ₄ are electron donating groups having a Hammett's substituent constant being negative. .)

In the general formulas (V) to (VIII), preferred examples of the monovalent nonmetallic atomic group represented by X ₁ to X ₄ and R ₆ to R ₂₁ include a hydrogen atom, an alkyl group (for example, a 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, 2-norbornyl group, chloromethyl group , Bromomethyl group, 2-chloroethyl group, trifluoromethyl group, methoxymethyl group, methoxy ester Toxiethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl Group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxycarbonylbutyl group, chloro Phenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, -Methyl-N- (sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfa Moylpropyl group, N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methyl Phosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonatoxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group P-methylbenzyl group , Cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, etc.), aryl group ( For example, phenyl group, biphenyl group, naphthyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group , Acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl Phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, nitrophenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, phosphonatophenyl group, etc.), heteroaryl group (for example, thiophene, Thiathrene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, indoyl, indazole, purine, quinolidine, isoquinoline, Phthalazine, naphthyridine, quinazoline, cinolin, pteridine, carbazole, carboline, phenanthrine, acridine, perimidine, phenanthroline, phthalazine, phena A group derived from a heteroaryl ring such as zazine, phenoxazine, furazane, phenoxazine), an alkenyl group (for example, vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group, 2-chloro-1-ethenyl group, Etc.), alkynyl groups (eg, ethynyl group, 1-propynyl group, 1-butynyl group, trimethylsilylethynyl group, etc.), halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups, alkoxy groups, 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-alkyl Rucarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy 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-aryl Ureido group, N ′, N′-dialkyl-N-alkylureido group, ', N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N'-aryl-N-arylureido group, N', N'-diaryl-N-alkylureido group, N ', N'-diaryl-N-arylureido group, N'-alkyl-N'-aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, Aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group Group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl Carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, alkylsulfinyl group, arylsulfinyl group, Alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group (hereinafter referred to as sulfonate group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group , N, N-Dial Kill sulfamoyl group, N- aryl sulfamoyl group, N, N- diaryl sulfamoyl group, N- alkyl -N- arylsulfamoyl group, a phosphono group (-PO ₃ H ₂₎ and its conjugated base group ( Hereinafter, referred to as a phosphonate group), a dialkyl phosphono group (—PO ₃ (alkyl) ₂ ), a diaryl phosphono group (—PO ₃ (aryl) ₂ ), an alkylaryl phosphono group (—PO ₃ (alkyl) (aryl). )), Monoalkyl phosphono group (—PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkyl phosphonate group), monoaryl phosphono group (—PO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as aryl phosphonophenyl group), phosphonooxy group (-OPO ₃ H ₂₎ and its conjugated base group (hereinafter Phosphodiesterase referred to isocyanatomethyl group), dialkyl phosphonooxy group _{(-OPO 3 (alkyl) 2)} , diaryl phosphonooxy group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphonooxy group (-OPO ₃ (alkyl ) (Aryl)), a monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as an alkylphosphonatooxy group), a monoarylphosphonooxy group (—OPO ₃ H ( aryl)) and its conjugated base group (hereinafter referred to as arylphosphonatooxy group), cyano group, nitro group, and the like. Among the above substituents, a hydrogen atom, an alkyl group, an aryl group, a halogen atom, An alkoxy group and an acyl group are particularly preferable.

  Examples of the basic nucleus of the dye formed together with A adjacent to Y in the general formula (V) and the adjacent carbon atom include 5-, 6-, and 7-membered nitrogen-containing or sulfur-containing heterocycles. A 5- or 6-membered heterocyclic ring is preferable.

  Examples of nitrogen-containing heterocycles include L. G. Brooker et al. , J .; Am. Chem. Soc. 73, 5326-5358 (1951). Any of those known to constitute a basic nucleus in the merocyanine dyes described in the literature and the references can be suitably used. Specific examples include thiazoles (for example, thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4,5- Di (p-methoxyphenylthiazole), 4- (2-thienyl) thiazole, etc.), benzothiazoles (for example, benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, 7- Chlorobenzothiazole, 4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 4-phenylbenzothiazole, 5-phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzo Cheer , 6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-di Oxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6-hydroxybenzothiazole, 6-dimethylaminobenzothiazole, 5-ethoxycarbonylbenzothiazole, etc.), naphthothiazoles (for example, naphtho [1,2] thiazole, naphtho [2 , 1] thiazole, 5-methoxynaphtho [2,1] thiazole, 5-ethoxynaphtho [2,1] thiazole, 8-methoxynaphtho [1,2] thiazole, 7-methoxynaphtho [1,2] thiazole, etc.) , Chianafuteno 7 ′, 6 ′, 4,5-thiazole (for example, 4′-methoxythianaphtheno-7 ′, 6 ′, 4,5-thiazole, etc.), oxazole (for example, 4-methyloxazole, 5-methyloxazole) 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, 5-phenyloxazole, etc.), benzoxazoles (benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole) 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 6-methoxybenzoxazole, 5-methoxybenzoxazole, 4-ethoxybenzoxazole, 5-chloroben Zoxazole, 6-methoxybenzoxazole, 5-hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.), naphthoxazoles (eg, naphtho [1,2] oxazole, naphtho [2,1] oxazole, etc.), selenazoles ( For example, 4-methylselenazole, 4-phenylselenazole, etc.), benzoselenazoles (for example, benzoselenazole, 5-chlorobenzoselenazole, 5-methoxybenzoselenazole, 5-hydroxybenzoselenazole, tetrahydrobenzo Selenazole etc.), naphthoselenazoles (eg naphtho [1,2] selenazole, naphtho [2,1] selenazole etc.), thiazolines (eg thiazoline, 4-methylthiazoline etc.), quinolines (eg quinoline) , 3-methyl Quinoline, 5-methylquinoline, 7-methylquinoline, 8-methylquinoline, 6-chloroquinoline, 8-chloroquinoline, 6-methoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinoline, 8-hydroxyquinoline, etc.), isoquinoline (Eg, isoquinoline, 3,4-dihydroisoquinoline, etc.), benzimidazoles (eg, 1,3-diethylbenzimidazole, 1-ethyl-3-phenylbenzimidazole, etc.), 3,3-dialkylindolenins ( For example, 3,3-dimethylindolenine, 3,3,5, -trimethylindolenine, 3,3,7, -trimethylindolenine, etc.), pyridines (for example, pyridine, 5-methylpyridine, etc.), etc. be able to.

Examples of the sulfur-containing heterocycle include a dithiol partial structure in dyes described in JP-A-3-296759.
Specific examples include benzodithiols (for example, benzodithiol, 5-t-butylbenzodithiol, 5-methylbenzodithiol, etc.), naphthodithiols (for example, naphtho [1,2] dithiol, naphtho [2,1] Dithiols, etc.), dithiols (for example, 4,5-dimethyldithiols, 4-phenyldithiols, 4-methoxycarbonyldithiols, 4,5-dimethoxycarbonyldithiols, 4,5-ditrifluoromethyldithiols, 4, Examples include 5-dicyanodithiol, 4-methoxycarbonylmethyldithiol, 4-carboxymethyldithiol, and the like.

  As mentioned above, the description used for the description of the heterocyclic ring described above has conventionally used the name of the heterocyclic mother skeleton for convenience, but in the case of the basic skeleton partial structure of the sensitizing dye, for example, in the case of the benzothiazole skeleton , 3-substituted-2 (3H) -benzothiazolylidene groups, such as alkylidene type substituents with one degree of unsaturation.

  Of the sensitizing dyes having an absorption maximum in a wavelength range of 360 nm to 450 nm, a dye more preferable from the viewpoint of high sensitivity is a dye represented by the following general formula (IX).

(In the general formula (IX), A represents an aromatic ring group or a heterocyclic group which may have a substituent, and X represents an oxygen atom, a sulfur atom or N (R ₃ ). R ₁ , R ₂ And R ₃ each independently represents a monovalent nonmetallic atomic group, and A and R ₁ or R ₂ and R ₃ may be bonded to each other to form an aliphatic or aromatic ring. Good.)

General formula (IX) will be described in more detail. R ₁ , R ₂ and R ₃ are each independently a monovalent nonmetallic atomic group, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group Represents a substituted or unsubstituted aromatic heterocyclic residue, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a hydroxyl group, or a halogen atom.

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

As the substituent of the substituted alkyl group, a monovalent nonmetallic atomic group excluding hydrogen is used, and preferred examples include a halogen atom (—F, —Br, —Cl, —I), a hydroxyl group, an alkoxy group, Aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, Reelsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N'-alkylureido group, N ', N'-dialkylureido group, N'-arylureido Group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N′- Alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N'- Aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-ary Luureido 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, 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, alkylsulfinyl Group, Arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group (hereinafter referred to as sulfonate group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkyls Rufinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkyl Sulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group (-PO ₃ H ₂₎ and its conjugated base group (hereinafter referred to as phosphonato group , Dialkyl phosphono group _{(-PO 3 (alkyl) 2)} , diaryl phosphono group _{(-PO 3 (aryl) 2)} , alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )), monoalkyl phosphono Group (—PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkylphosphonate group), monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as arylphosphine group). A phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as a phosphonatooxy group), a dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), a diarylphosphine Fonookishi group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphonooxy group (-OPO ₃ (alkyl (Aryl)), monoalkyl phosphonooxy group (-OPO ₃ H (alkyl)) and its conjugated base group (hereinafter referred to as alkyl phosphonophenyl group), monoaryl phosphonooxy group (-OPO ₃ H (aryl )) And conjugated base groups thereof (hereinafter referred to as arylphosphonatooxy groups), cyano groups, nitro groups, aryl groups, heteroaryl groups, alkenyl groups, and alkynyl groups.

  Specific examples of the alkyl group in these substituents include the above-described alkyl groups, and specific examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, a tolyl group, a xylyl group, a mesityl group, and a cumenyl group. , Chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylamino Phenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group Cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl phenyl group, phosphonophenyl phenyl group and the like.

  As the heteroaryl group, a monocyclic or polycyclic aromatic ring group containing at least one of nitrogen, oxygen and sulfur atoms is used. Examples of particularly preferred heteroaryl groups include, for example, thiophene, thiathrene, furan , Pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, indoyl, indazole, purine, quinolidine, isoquinoline, phthalazine, naphthyridine , Quinazoline, cynoline, pteridine, carbazole, carboline, phenanthrine, acridine, perimidine, phenanthroline, phthalazine, phenazazine, phenoxazine, furazane, phenoxazine, etc. Groups derived are exemplified by these may be further benzo-fused or may have a substituent.

Examples of alkenyl groups include vinyl, 1-propenyl, 1-butenyl, cinnamyl, 2-chloro-1-ethenyl, etc. Examples of alkynyl include ethynyl, 1 -Propynyl group, 1-butynyl group, trimethylsilylethynyl group and the like. Examples of G ₁ in the acyl group (G ₁ CO—) include hydrogen and the above alkyl groups and aryl groups. Among these substituents, even more preferred are halogen atoms (—F, —Br, —Cl, —I), alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, N-alkylamino groups, N, N— Dialkylamino group, acyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, acylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonate group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group Group, N-arylsulfa Yl group, N-alkyl-N-arylsulfamoyl group, phosphono group, phosphonate group, dialkyl phosphono group, diaryl phosphono group, monoalkyl phosphono group, alkyl phosphonate group, monoaryl phosphono group, aryl phosphine group Examples include an onato group, a phosphonooxy group, a phosphonateoxy group, an aryl group, and an alkenyl group.

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

Specific examples of preferred substituted alkyl groups as R ₁ , R ₂ and R ₃ obtained by combining the above substituents with an alkylene group include chloromethyl group, bromomethyl group, 2-chloroethyl group, trifluoromethyl group, methoxymethyl Group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N- Cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbo Nylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl- N- (sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobu Group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonateoxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p -Methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, etc. Can be mentioned.

Specific examples of preferred aryl groups as R ₁ , R ₂ and R ₃ include those in which 1 to 3 benzene rings form a condensed ring, and those in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group, and among these, a phenyl group and a naphthyl group are more preferable.

Specific examples of preferred substituted aryl groups as R ₁ , R ₂ and R ₃ include those having a monovalent non-metallic atomic group excluding hydrogen as a substituent on the ring-forming carbon atom of the aryl group described above. . Examples of preferred substituents include the alkyl groups, substituted alkyl groups, and those previously shown as substituents in the substituted alkyl group. Preferred examples of such a substituted aryl group include biphenyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, fluorophenyl group, chloromethylphenyl group, trifluoromethylphenyl group. Hydroxyphenyl group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl group, phenoxyphenyl group, methylthiophenyl group, tolylthiophenyl group, ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, acetyloxyphenyl group, Benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group, acetylaminophenyl group, N-methylbenzoylaminophenyl group, carbo Cyphenyl group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, carbamoylphenyl group, N-methylcarbamoylphenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) carbamoylphenyl group N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, phosphonophenyl group, phosphonatophenyl group, diethylphosphonophenyl group, diphenylphosphono Enyl group, methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonatophenyl group, allylphenyl group, 1-propenylmethylphenyl group, 2-butenylphenyl group, 2-methylallylphenyl Group, 2-methylpropenylphenyl group, 2-propynylphenyl group, 2-butynylphenyl group, 3-butynylphenyl group and the like.

Examples of preferred substituted or unsubstituted alkenyl groups and substituted or unsubstituted aromatic heterocyclic residues as R ₁ , R ₂ and R ₃ are the same as those described above for alkenyl groups and heteroaryl groups. Can be mentioned.

Next, A in the general formula (IX) will be described. A represents an aromatic ring group or a heterocyclic group which may have a substituent, and specific examples of the aromatic ring group or the heterocyclic group which may have a substituent include those in the general formula (IX) Examples thereof are the same as those described for R ₁ , R ₂ and R ₃ .

  The sensitizing dye represented by the general formula (IX) of the present invention is a condensation reaction between an acidic nucleus having an acidic nucleus or an active methylene group as shown above and a substituted or unsubstituted aromatic ring or heterocyclic ring. Obtained by. Specifically, it can be synthesized with reference to the description of JP-B-59-28329.

  Preferred specific examples (D1) to (D75) of the compound represented by the general formula (IX) are shown below. In addition, an isomer with a double bond connecting an acidic nucleus and a basic nucleus is not limited to either isomer.

Details of the usage such as which structure of these sensitizing dyes are used, whether they are used alone or in combination of two or more, and the addition amount can be appropriately set in accordance with the performance design of the lithographic printing plate precursor.
For example, the compatibility with the photosensitive layer can be increased by using two or more sensitizing dyes in combination. In selecting the sensitizing dye, in addition to the photosensitivity, the molar extinction coefficient at the emission wavelength of the light source used is an important factor. By using a dye having a large molar extinction coefficient, the amount of the dye added can be made relatively small, which is economical and advantageous when used for a lithographic printing plate precursor in terms of film physical properties of the photosensitive layer. is there. Since the photosensitivity and resolution of the photosensitive layer and the physical properties of the exposure film are greatly affected by the absorbance at the light source wavelength, the addition amount of the sensitizing dye is appropriately selected in consideration of these.

  However, for example, for the purpose of curing a thick film having a thickness of 5 μm or more, the degree of curing may be increased by lower absorbance. When used as a lithographic printing plate precursor used in a relatively thin film thickness, the addition amount of the sensitizing dye is such that the absorbance of the photosensitive layer of the present invention is in the range of 0.1 to 1.5, preferably from 0.25. It is preferable to set so as to be in the range of 1. Usually, the amount is preferably 0.05 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and most preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the total solid content of the photosensitive layer.

(B) Polymerization initiator The photosensitive layer of the invention contains a polymerization initiator (hereinafter also referred to as an initiator compound). The initiator compound is a compound that undergoes a chemical change through the action of electron transfer, energy transfer, heat generation, etc. caused by the electronic excitation state of the sensitizing dye, and generates at least one selected from radicals, acids, and bases. is there. Hereinafter, radicals, acids, and bases generated in this way are simply referred to as active species. When the initiator compound is not present or when only the initiator compound is used alone, practically sufficient sensitivity cannot be obtained. As one mode in which a sensitizing dye and an initiator compound are used in combination, they can be used as a single compound by an appropriate chemical method (such as linking a sensitizing dye and an initiator compound through a chemical bond). It is.

  Usually, many of these initiator compounds are considered to generate active species through the initial chemical processes represented by the following (1) to (3). (1) Reductive decomposition of the initiator compound based on the electron transfer reaction from the electronically excited state of the sensitizing dye to the initiator compound, (2) Electron transfer from the initiator compound to the electronically excited state of the sensitizing dye (3) decomposition of the initiator compound from the electronically excited state based on energy transfer from the electronically excited state of the sensitizing dye to the initiator compound. Although it is often ambiguous as to which type of (1) to (3) each individual initiator compound belongs, the sensitizing dye in the present invention is extremely in combination with any of these types of initiator compounds. Shows a high sensitizing effect.

As the initiator compound in the present invention, those known to those skilled in the art can be used without limitation, and specifically, for example, Bruce M. Monroe et al., Chemical Revue, 93, 435 (1993), R.
S. Davidson, Journal of Photochemistry and biology A: Chemistry, 73. 81 (1993), JP Faussier, Photoinitiated Polymerization-Theory and Applications: Rapra Review vol. 9, Report, Rapra Technology (1998), M. Tsunooka et al. , Prog. Polym. Sci., 21, 1 (1996), and many other compounds can be used. Further, as other compounds having the functions of (1) and (2), FD Saeva, Topics in Current Chemistry, 156, 59 (1990), GG Maslak, Topics in Current Chemistry, 168, 1 (1993) Year), HB Shuster et al, JACS, 112, 6329 (1990), IDF Eaton et al, JACS, 102, 3298 (1980), etc. A group of compounds can also be used as initiator compounds.

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

(A) Those that are reduced to cause bond cleavage and generate active species.
Compound having carbon-halogen bond: It is considered that a carbon-halogen bond is reductively cleaved to generate an active species (for example, described in Polymer Preprints, Jpn., 41 (3) 542 (1992)). ). As the active species, radicals and acids can be generated. Specifically, for example, in addition to halomethyl-s-triazines, MP Hutt, EF Elslager and LM Merbel Journal
of Heterocyclic chemistry, 7, 511 (1970), and halomethyloxadiazoles which can be easily synthesized by those skilled in the art, and German Patent Nos. 2641100, 3333450, 3021590, and 3021599. Can be preferably used.
Compound having nitrogen-nitrogen bond or nitrogen-containing heterocycle-nitrogen-containing heterocycle bond: reductive bond cleavage (for example, described in J. Pys. Chem., 96, 207 (1992)) . Specifically, hexaarylbiimidazoles and the like are preferably used. The active species to be generated are lophine radicals, which together with a hydrogen donor if necessary, initiate radical chain reaction, and image formation using oxidation reaction with lophine radicals is also known (J. Imaging Sci., 30 , 215 (1986)).

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

  Onium compound: It is considered that a carbon-hetero bond or oxygen-nitrogen bond is reductively cleaved to generate an active species (for example, as described in J. Photopolym. Sci. Technol., 3, 149 (1990)). ) Specifically, for example, iodonium salts described in European Patent No. 104143, U.S. Pat. No. 4,837,124, Japanese Patent Laid-Open No. 2-150848, and Japanese Patent Laid-Open No. 2-96514, European Patent Nos. 370693, 233567, 297443, 293442, 279210, 422570, U.S. Pat. Nos. 3,902,144, 4,933,377, 4,760013, 4,734,344 and 2,833,827, sulfonium salts and diazonium salts (which may have a substituent) Diazonium, etc.), diazonium salt resins (formaldehyde resin of diazodiphenylamine, etc.), N-alkoxypyridinium salts, etc. (for example, US Pat. No. 4,743,528, JP-A-63-138345, JP-A-63-142345) , JP-A-6 -142346, Japanese Patent Publication No. 46-42363, etc., specifically 1-methoxy-4-phenylpyridinium tetrafluoroborate, etc.), and further, Japanese Patent Publication Nos. 52-14727 and 52-14728. The compounds described in JP-A-52-14729 are preferably used. Generates radicals and acids as active species.

Active esters: nitrobenzyl esters of sulfonic acid and carboxylic acid, esters of sulfonic acid and carboxylic acid and N-hydroxy compounds (N-hydroxyphthalimide, oxime, etc.), sulfonic acid esters of pyrogallol, naphthoquinone diazide-4 -Sulfonates can be reductively decomposed. As the active species, radicals and acids can be generated. Specific examples of the sulfonic acid esters include European Patent Nos. 0290750, 046083, 156153, 271851, 0388343, U.S. Pat. Nos. 3,901,710 and 4,181,531, JP-A-60-198538. Nitrobenzle ester compounds described in JP-A-53-133022, European Patents 0196672, 84515, 199672, 044115, 0101122, US Pat. Nos. 4,618,564, 4371605, and 4431774, The iminosulfonate compounds described in JP-A-64-18143, JP-A-2-245756, JP-A-4-365048, JP-B-62-2223, JP-B-63-14340, JP-A-59-174831 Compounds, etc. For example compounds may be mentioned below.

  (In the formula, Ar represents an aromatic group or an aliphatic group which may be substituted.)

Moreover, it is also possible to produce | generate a base as an active species, for example, the following compound groups are known.
Ferrocene and iron arene complexes: An active radical can be reductively generated. Specifically, for example, they are disclosed in JP-A-1-304453 and JP-A-1-152109.

(In the formula, R represents an optionally substituted aliphatic group or aromatic group.)
Disulfones: Reducing S—S bond reductively and generating an acid. For example, diphenyl disulfones as described in JP-A 61-166544 are known.

(B) Those that are oxidized to cause bond cleavage and generate active species.
Alkylate complex: It is considered that an active radical is generated by oxidative cleavage of a carbon-hetero bond (for example, as described in J. Am. Chem. Soc., 112, 6329 (1990)). Specifically, for example, triarylalkyl borates are preferably used.

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

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

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

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

(C) Although the sensitization mechanism is not clear, the compound can function as an initiator compound. Other sensitization mechanisms are not clear, but many of them can function as an initiator compound, and these are also the initiators in the present invention. It can be used as a compound. For example, organometallic compounds such as titanocene compounds and ferrocene compounds, aromatic ketones, acylphosphine, bisacylphosphine and the like can be mentioned, and radicals or acids can be generated as active species.

Hereinafter, among the initiator compounds used in the present invention, a preferred compound group particularly excellent in sensitivity and stability will be specifically exemplified.
(1) Halomethyltriazines Examples of halomethyltriazines include compounds represented by the following formula [II]. Particularly excellent in radical generation and acid generation ability.

In the formula [II], X represents a halogen atom. Y ¹ represents —CX ₃ , —NH ₂ , —NHR ₂ , —N (R ₂ ) ₂ , —OR ₂ . Here, R ₂ represents an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. R ¹ represents —CX ₃ , an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or a substituted alkenyl group.
Specific examples of such compounds include, for example, Wakabayashi et al., Bull. Chem. Soc. Japan, 4
2, 2924 (1969), for example, 2-phenyl-4,6-bis (trichloromethyl) -S-triazine, 2- (p-chlorophenyl) -4,6-bis (trichloromethyl) -S -Triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (2 ′, 4′-dichlorophenyl) -4,6-bis (trichloromethyl) -S-triazine, 2,4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6- Bis (trichloromethyl) -S-triazine, 2-n-nonyl-4,6-bis (trichloromethyl) -S-triazine, 2- (α, α, β-trichloroethyl) -4,6-bis (trichloro Methyl) -S- triazine. In addition, compounds described in GB 1388492, for example, 2-styryl-4,6-bis (trichloromethyl) -S-triazine, 2- (p-methylstyryl) -4,6-bis (trichloromethyl) ) -S-triazine, 2- (p-methoxystyryl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxystyryl) -4-amino-6-trichloromethyl-S-triazine Compounds described in JP-A-53-133428, such as 2- (4-methoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxy-naphtho) -1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- [4- (2-ethoxyethyl) -naphth-1-yl] -4,6-bis-trichloromethyl S-triazine, 2- (4,7-dimethoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (acenaphtho-5-yl) -4,6-bis-trichloro Examples thereof include methyl-S-triazine and the compounds described in DE 3337024, JP-A 62-58241, and JP-A 5-281728.

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

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

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

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

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

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

Examples of the alkenyl group of RR ^{51 to} R ⁵⁴ include straight chain, branched, and cyclic groups having 2 to 18 carbon atoms, and examples of the substituent for the substituted alkenyl group include those for the substituted alkyl group. Is included.

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

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

Specific examples of the compound represented by the formula [III] are specifically US Pat. No. 3,567,453, 4
No. 343891, European Patent Nos. 109772 and 109773, and the compounds shown below.

(4) Hexaarylbiimidazoles Excellent in stability and capable of generating highly sensitive radicals. Specifically, lophine dimers described in JP-B Nos. 45-37377 and 44-86516, for example, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′- Tetraphenylbiimidazole, 2,2′-bis (o-bromophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole, 2,2'-bis (O, o'-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4,4', 5,5'-tetraphenylbiimidazole Imidazole, 2,2'-bis (o- Methylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2
2,2′-bis (o-trifluoromethylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole and the like.

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

(6) Organic peroxide When an organic peroxide type initiator compound is used, radicals can be generated as active species with very high sensitivity.
The organic peroxide includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples thereof include methyl ethyl ketone peroxide, cyclohexanone peroxide, and 3,3,5-trimethylcyclohexanone. Peroxide, methylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 2, 2-Bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paraffin hydroperoxide, 2,5-dimethylhexane-2,5-dihydride Peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, bis (t-butylperoxyisopropyl) benzene, 2 , 5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, acetyl peroxide, isobutyryl peroxide, Octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, succinic peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, meta-toluoyl peroxide , Diisopropyl peroxy dicarbonate Di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, t-butyl peroxyacetate , T-butylperoxypivalate, t-butylperoxyneodecanoate, t-butylperoxyoctanoate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxy Laurate, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylmaleic acid, t-butylper Oxyisopropyl carbonate, 3,3 ′, 4,4 ′ − Tra- (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-hexylper) Oxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-octylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (cumylperoxycarbonyl) benzophenone, 3,3 ′, Examples include 4,4′-tetra (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogen diphthalate), carbonyldi (t-hexylperoxydihydrogendiphthalate), and the like.

  Among these, 3,3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (t-amylperoxycarbonyl) benzophenone, 3 , 3 ′, 4,4′-tetra (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-octylperoxycarbonyl) benzophenone, 3,3 ′, 4,4 ′ Peroxyesters such as tetra (cumylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (p-isopropylcumylperoxycarbonyl) benzophenone, di-t-butyldiperoxyisophthalate are preferred. .

(7) Titanocene compound As the titanocene compound suitable for the initiator compound, JP-A 59-152396, JP-A 61-151197, JP-A 63-41484, JP-A 2-249, JP-A 2-2 And titanocene compounds described in each publication such as -4705.

  Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl. Di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6-trifluorophen-1 -Yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, di-methylcyclopenta Dienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1 − Di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyridin-1-yl) Phenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (methylsulfonamido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- Butylbialoyl-amino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-ethylacetylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-methylacetyl) Amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-ethylpropionylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3 -(N-ethyl- (2,2-dimethylbutanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butyl- (2,2-dimethylbutane) Noyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-pentyl- (2,2-dimethylbutyl) Noyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-hexyl)-(2,2-dimethylbutanoyl) phenyl] titanium, bis (cyclopentadienyl) ) Bis [2,6-difluoro-3- (N-methylbutyrylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-methylpentanoylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-ethylcyclohexylcarbonylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-ethyl) Isobutyrylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-ethylacetylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6- Difluoro-3- (2,2,5,5-tetramethyl-1,2,5-azadisilolidin-1-yl) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- ( Octylsulfonamido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (4-tolylsulfonamide) Phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (4-dodecylphenyl sulfonyl) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (4- (1-pentylheptyl) phenylsulfonylamido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3 -(Ethylsulfonylamido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3-((4-bromophenyl) -sulfonylamido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2-naphthylsulfonylamido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (hexadecylsulfonylamido) phenyl] titanium, bis (cyclo Pentadienyl) bis [2,6-difluoro-3- (N-methyl- (4-dodecylphenyl)] Ruhoniruamido) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-methyl-4- (1-pentylheptyl) phenyl) sulfonylamide)] titanium, bis (cyclopentadienyl) bis [2,6 -Difluoro-3- (N-hexyl- (4-tolyl) -sulfonylamido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (pyrrolidine-2,5-dioni-1) -Yl) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (3,4-dimethyl-3-pyrrolidin-2,5-dioni-1-yl) phenyl] titanium, bis (Cyclopentadienyl) bis [2,6-difluoro-3- (phthalimido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3 Isobutoxycarbonylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (ethoxycarbonylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro- 3-((2-chloroethoxy) -carbonylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (phenoxycarbonylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (3-phenylthioureido) Phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (3-butylthioureido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- ( 3-phenylureido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (3-butylureido) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro -3- (N, N-diacetylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro 3- (3,3-dimethyl-ureido) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (acetylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (butyrylamino) phenyl] titanium, bis (Cyclopentadienyl) bis [2,6-difluoro-3- (decanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (octadecanoylamino) phenyl] Titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (isobutyrylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2-ethyl) Hexanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2-methylbuta) Ylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (pivaloylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (2,2-dimethylbutanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2 -Ethyl-2-methylheptanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (cyclohexylcarbonylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2 , 6-Difluoro-3- (2,2-dimethyl-3-chloropropanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (3-phenylpropanoylamino) Phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2-chloromethyl-2-methyl) 3-chloro-propanoylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (3,4-xyloylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (4- Ethylbenzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2,4,6-mesitylcarbonylamino) phenyl] titanium, bis (cyclopentadienyl) bis [ 2,6-difluoro-3- (benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-phenylpropyl) benzoylamino) phenyl] titanium, bis (Cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-ethylheptyl) -2,2-dimethylpentanoylamino ] Phenyl titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-isobutyl- (4-toluyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6- Difluoro-3- (N-isobutylbenzoylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-cyclohexylmethylpivaloylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N -(Oxolan-2-ylmethyl) benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-ethylheptyl) -2,2-dimethylbutanoylamino ) Phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-phenylpropyl- (4-toluyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (oxolani-2-ylmethyl)-(4-toluyl) amino) phenyl] titanium, bis (si Ropentajieniru) bis [2,6-difluoro -3- (N- (4- Toruirumechiru) benzoylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (4-toluylmethyl)-(4-toluyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6 -Difluoro-3- (N-butylbenzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butyl- (4-toluyl) amino) phenyl] titanium, bis (Cyclopentadienyl) bis [2,6-difluoro-3- (N-hexyl- (4-toluyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- ( N- (2,4-dimethylpentyl) -2,2-dimethylbutanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro- - (2,4-dimethylpentyl) -2,2-dimethyl pentanoylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3-((4-toluyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2,2 -Dimethylpentanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2,2-dimethyl-3-ethoxypropanoylamino) phenyl] titanium, bis (cyclopentadi) Enyl) bis [2,6-difluoro-3- (2,2-dimethyl-3-allyloxypropanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N -Allylacetylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (2-ethylbutanoylamino) Phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3-(N-cyclohexylmethyl-benzoylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-cyclohexylmethyl- (4-toluyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3 -(N- (2-ethylhexyl) benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-isopropylbenzoylamino) phenyl] titanium, bis (cyclopentadienyl) ) Bis [2,6-difluoro-3- (N- (3-phenylpropyl) -2,2-dimethylpentanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro- 3- (N-hexylbenzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro -3- (N-cyclohexylmethyl-2,2-dimethylpentanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butylbenzoylamino) phenyl] titanium ,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (2-ethylhexyl) -2,2-dimethylpentanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2 , 6-Difluoro-3- (N-hexyl-2,2-dimethylpentanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-isopropyl-2,2 -Dimethylpentanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-phenylpropyl) pivaloylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butyl-2,2-dimethylpentanoylamino) phenyl] titanium, bis (cyclo Ntajieniru) bis [2,6-difluoro -3- (N- (2- methoxyethyl) benzoylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-benzylbenzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-benzyl- (4-Toluyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (2-methoxyethyl)-(4-toluyl) amino) phenyl] titanium, bis (Cyclopentadienyl) bis [2,6-difluoro-3- (N- (4-methylphenylmethyl) -2,2-dimethylpentanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2 , 6-Difluoro-3- (N- (2-methoxyethyl) -2,2-dimethylpentanoylamino) phenyl] titanium, bis (cyclopentadiene) Le) bis [2,6-difluoro-3-(N-cyclohexylmethyl - (2-ethyl-2-methyl-heptanoyl) amino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butyl- (4-chlorobenzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3 -(N-hexyl- (2-ethyl-2-methylbutanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-cyclohexyl-2,2-dimethyl) Pentanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (oxolani-2-ylmethyl) -2,2-dimethylpentanoyl) amino) phenyl] titanium Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-cyclohexyl- (4-chlorobenzoyl) amino) phenyl Titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-cyclohexyl- (2-chlorobenzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro -3- (3,3-dimethyl-2-azetidinoni-1-yl) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3-isocyanatophenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-ethyl- (4-tolylsulfonyl) ) Amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-hexyl- (4-tolylsulfonyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [ 2,6-difluoro-3- (N-butyl- (4-tolylsulfonyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-isobutyl- (4- Tolylsulfonyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butyl- (2,2-di) Chill -3 chloropropanoyl) amino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-phenylpropanoyl) -2,2-dimethyl-3-chloropropanoyl) amino) phenyl] titanium, bis (cyclopenta Dienyl) bis [2,6-difluoro-3- (N-cyclohexylmethyl- (2,2-dimethyl-3-chloropropanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6 -Difluoro-3- (N-isobutyl- (2,2-dimethyl-3-chloropropanoyl) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butyl- ( 2-chloromethyl-2-methyl-3-chloropropanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3 (Butyl thiocarbonyl amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (phenylthio carbonylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3-isocyanatophenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-ethyl- (4-tolylsulfonyl) ) Amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-hexyl- (4-tolylsulfonyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [ 2,6-difluoro-3- (N-butyl- (4-tolylsulfonyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-isobutyl- (4- Tolylsulfonyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3-
(N-butyl- (2,2-dimethyl-3-chloropropanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-phenylpropanoyl) ) -2,2-dimethyl-3-chloropropanoyl) amino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-cyclohexylmethyl- (2,2-dimethyl-3-chloropropanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-isobutyl- (2,2-dimethyl-3-chloropropanoyl) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N -Butyl- (2-chloromethyl-2-methyl-3-chloropropanoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (butylthiocarbonylamino) phenyl] Titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (phenylthiocarbonylamino) phenyl] titanium, bis Methylcyclopentadienyl) bis [2,6-difluoro-3-(N-hexyl-2,2-dimethyl-butanoylamino) amino) phenyl] titanium,

Bis (methylcyclopentadienyl) bis [2,6-difluoro-3- (N-hexyl-2,2-dimethylpentanoylamino) phenyl] titanium, bis (methylcyclopentadienyl) bis [2,6- Difluoro-3- (N-ethylacetylamino) phenyl] titanium, bis (methylcyclopentadienyl) bis [2,6-difluoro-3- (N-ethylpropionylamino) phenyl] titanium, bis (trimethylsilylpentadienyl) ) Bis [2,6-difluoro-3- (N-butyl-2,2-dimethylpropanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- ( 2-methoxyethyl) -trimethylsilylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6- Fluoro-3- (N-butylhexyldimethylsilylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-ethyl- (1,1,2, -trimethylpropyl) Dimethylsilylamino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (3-ethoxymethyl-3-methyl-2-azethiodinon-1-yl) phenyl] titanium, bis (cyclopentadienyl) bis [2, 6-difluoro-3- (3-allyloxymethyl-3-methyl-2-azetidinon-1-yl) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (3-chloro Methyl-3-methyl-2-azetidinoni-1-yl) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-benzyl-2,2-dimethylpropanoylamino) phenyl ] Titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (5,5-dimethyl-2-pyrrolidinoni-1-yl) phenyl] tita , Bis (cyclopentadienyl) bis [2,6-difluoro-3- (6,6-diphenyl-2-Piperijinoni-1-yl) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (2,3-dihydro-1,2-benzisothiazolo-3-one (1,1-dioxide) -2-yl) phenyl] Titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-hexyl- (4-chlorobenzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro -3- (N-hexyl- (2-chlorobenzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-isopropyl- (4-chlorobenzoyl) amino) Phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (4-methylphenylmethyl)-(4-chlorobenzoyl) a Roh) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3-(N-(4-methylphenyl methyl) - (2-chlorobenzoyl) amino) phenyl] titanium,

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

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

The polymerization initiator in the present invention is suitably used alone or in combination of two or more.
The amount of the polymerization initiator used in the photosensitive layer in the present invention is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, and still more preferably 1. It is 0-10 mass%.

(C) Polymerizable compound The polymerizable compound used in the photosensitive layer in the invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and preferably has at least one terminal ethylenically unsaturated bond, preferably It is selected from compounds having two or more. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, ie dimers, trimers and oligomers, or copolymers thereof, or mixtures thereof. Examples of monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids. An ester of an acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are 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 monofunctional or polyfunctional 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.

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

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

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate Sorbitol tetritaconate, etc. Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, JP-A-59- Those having an aromatic skeleton described in JP-A No. 5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.
Furthermore, the ester monomers described above can also be used as a mixture.

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

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

_{CH 2 = C (R 4)} COOCH 2 CH (R 5) OH (A)
(However, R ₄ and R ₅ represent H or CH _3. )

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56- Urethane compounds having an ethylene oxide skeleton described in Japanese Patent No. 17654, Japanese Patent Publication No. 62-39417, and Japanese Patent Publication No. 62-39418 are also suitable. Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the case, it is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

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

About these polymerizable compounds, the details of usage such as the structure, single use or combination, addition amount, etc. can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.
From the viewpoint of 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. Further, 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.
In addition, the compatibility and dispersibility with other components in the photosensitive layer (for example, binder polymer, polymerization initiator, colorant, etc.), the selection and use method of the polymerizable compound is an important factor. 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 adhesion to a support or a protective layer described later. In addition, the use method of the polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface adhesiveness, etc. The layer configuration and coating method such as undercoating and overcoating can be considered.

  The polymerizable compound is preferably used in the range of 5 to 75% by mass, more preferably 25 to 70% by mass, and particularly preferably 30 to 60% by mass with respect to the total solid content of the photosensitive layer.

(D) Binder polymer The binder polymer used in the photosensitive layer according to the invention is a specific acrylic resin having an acid value of 0.3 meq / g or less. Specifically, (1) an acrylic resin having a hydrophilic group and a crosslinkable group having an acid value of 0.3 meq / g or less (hereinafter also referred to as acrylic resin 1) or (2) an SP value of 19.0 to 21 .5 (MPa) ^1/2 and an acid value of 0.3 meq / g or less (hereinafter also referred to as “acrylic resin 2”). Here, the acid value represents the acid content per gram of the acrylic resin by the number of chemical equivalents. The acid value of the acrylic resin is preferably 0.1 meq / g or less.

Below, the acrylic resins 1 and 2 used for this invention are demonstrated in detail.
The hydrophilic group possessed by the acrylic resin 1 used in the present invention is selected from monovalent or divalent or higher non-acidic hydrophilic groups such as a hydroxy group, a carboxylate group, a hydroxyethyl group, an ethyleneoxy group, a hydroxy group. A propyl group, an amino group, an aminoethyl group, an aminopropyl group, an ammonium group, an amide group, a carboxymethyl group, an ether group, or a salt obtained by neutralizing an acid group such as carboxylic acid, sulfonic acid or phosphoric acid is preferable. group, -CH ₂ CH ₂ O- repeating units, or, -CH ₂ CH ₂ NH- repeating unit is preferred.

  The content of the unit having a hydrophilic group is preferably 1 to 70 mol% in the acrylic resin 1 from the viewpoint of developability. Considering compatibility between developability and printing durability, the content is more preferably 1 to 50 mol%, particularly preferably 1 to 30 mol%.

  The acrylic resin 1 has a crosslinkable group. Here, the crosslinkable group is a group that crosslinks the acrylic resin binder in the process of radical polymerization reaction that occurs in the photosensitive layer when the lithographic printing plate precursor is exposed. Although it will not specifically limit if it is a group of such a function, For example, an ethylenically unsaturated bond group, an amino group, an epoxy group etc. are mentioned as a functional group which can be addition-polymerized. Moreover, the functional group which can become a radical by light irradiation may be sufficient, As such a crosslinkable functional group, a thiol group, a halogen group, an onium salt structure etc. are mentioned, for example. Especially, an ethylenically unsaturated bond group is preferable and the functional group represented by the following general formula (1)-(3) is especially preferable.

In the general formula (1), R ^{1 to} R ³ each independently represent a hydrogen atom or a monovalent organic group. R ¹ is preferably a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom or a methyl group is preferable because of high radical reactivity. R ² and R ³ are each independently a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an optionally substituted alkyl group, or a substituted group. An aryl group which may have a group, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, and a substituent An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable because of high radical reactivity.

X represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² represents a hydrogen atom or a monovalent organic group. Here, examples of the monovalent organic group include an alkyl group which may have a substituent. Among these, as R ¹² , a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group is preferable because of high radical reactivity.

  Here, examples of the substituent that can be introduced include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom, an amino group, an alkylamino group, an arylamino group, a carboxyl group, an alkoxycarbonyl group, A sulfo group, a nitro group, a cyano group, an amide group, an alkylsulfonyl group, an arylsulfonyl group and the like can be mentioned.

In the general formula (2), R ^{4 to} R ⁸ each independently represent a hydrogen atom or a monovalent organic group. R ^{4 to} R ⁸ are preferably a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, An aryl group that may have a substituent, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent. An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a group and an aryl group which may have a substituent are preferable.

Examples of the substituent that can be introduced are the same as those in the general formula (1). Y represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —. R ¹² has the same meaning as R ^{12 in} formula (1), and preferred examples thereof are also the same.

In the general formula (3), R ⁹ represents a hydrogen atom or a monovalent organic group. Preferable examples include a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom and a methyl group are preferable because of high radical reactivity. R ¹⁰ and R ¹¹ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or an alkyl group which may have a substituent. An aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, a substituent An arylamino group that may have, an alkylsulfonyl group that may have a substituent, an arylsulfonyl group that may have a substituent, and the like, among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable because of high radical reactivity.

Here, examples of the substituent that can be introduced are the same as those in the general formula (1). Z represents an oxygen atom, a sulfur atom, —N (R ¹³ ) —, or an optionally substituted phenylene group. Examples of R ¹³ include an alkyl group which may have a substituent. Among them, a methyl group, an ethyl group, and an isopropyl group are preferable because of high radical reactivity.

In the acrylic resin 1, for example, free radicals (polymerization initiation radicals or growth radicals in the polymerization process of a polymerizable compound) are added to the crosslinkable functional group, and are added directly between polymers or via a polymerization chain of the polymerizable compound. Polymerizes to form crosslinks between the polymer molecules and cure.
Alternatively, atoms in the polymer (for example, hydrogen atoms on carbon atoms adjacent to the crosslinkable functional group) are extracted by free radicals to form polymer radicals that are bonded to each other, thereby causing crosslinking between polymer molecules. Forms and cures.

  The content of the crosslinkable group in the acrylic resin 1 (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol, more preferably 1 g per 1 g of the acrylic resin 1. It is 1.0-7.0 mmol, Most preferably, it is 2.0-5.5 mmol.

  Further, from the viewpoint of improving printing durability, the crosslinkable group is desirably in the vicinity of the hydrophilic group, and more preferably, the hydrophilic group and the crosslinkable group are on the same polymer unit. Examples of such a polymerized unit having a crosslinkable group and a hydrophilic group include a repeating unit having a group represented by the following general formula (4) or a repeating unit represented by the following general formula (5). preferable.

In the general formulas (4) and (5), P represents a hydrophilic group, preferably an amide group, —CH ₂ CH ₂ O—repeating unit or —CH ₂ CH ₂ NH—repeating unit, and the like, Q ^{1 to} Q ³ represents a single bond, an alkylene group which may have a substituent, or an arylene group which may have a substituent, and K represents a crosslinkable group, preferably the above general formulas (1) to (3 ) And the like.

The group represented by the general formula (4) may be present anywhere in the monomer unit. When Q < ¹ > is an alkylene group, 1-7 are preferable, as for carbon number, 1-4 are more preferable, and 1-2 are especially preferable. In the repeating unit represented by the general formula (5), when Q ² and Q ³ are both alkylene groups or single bonds, the sum of the carbon numbers of Q ² and Q ³ is preferably 1 to 6, ~ 4 is more preferable, and 1-2 is particularly preferable. Further, when either Q ² or Q ³ is an arylene group, the other is preferably a single bond or an alkylene group having 1 to 4 carbon atoms, and more preferably an alkylene group having 1 to 2 carbon atoms.

Thus, in the case of a unit having a hydrophilic group and a crosslinkable group on the same polymerization unit, the crosslinking reaction proceeds in the vicinity of the hydrophilic group, so the printing durability due to the increase in the content of the hydrophilic group. The drop in is small. Therefore, such a unit can be contained in a larger amount than a unit having only a hydrophilic group. In the acrylic resin 1, the content of such a polymerized unit is preferably 1 to 90 mol%, and preferably 1 to 70 mol%. % Is more preferable, and 1 to 50 mol% is particularly preferable.
The hydrophilic group and the crosslinkable group may be introduced by copolymerization or may be introduced by a polymer reaction.

The acrylic resin 1 used in the present invention is a unit of an alkyl (meth) acrylate or an aralkyl ester in addition to the unit having a hydrophilic group, a unit having a crosslinkable group, a unit having a hydrophilic group and a crosslinkable group. It is preferable to have. The alkyl group of the (meth) acrylic acid alkyl ester is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group. Examples of (meth) acrylic acid aralkyl esters include benzyl (meth) acrylate.
The acrylic resin 1 used in the present invention preferably has substantially no acid group such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Moreover, it is preferable that the acrylic resin 1 used for this invention is insoluble with respect to water and aqueous solution of pH10 or more. The solubility of the acrylic resin in water or an aqueous solution having a pH of 10 or more (acrylic resin concentration at saturation dissolution) is preferably 1.0% by mass or less. The solubility measurement temperature is a normal temperature during plate-making development, and is 25 ° C. here.

The acrylic resin 1 preferably has a mass average molecular weight of 5,000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1,000 or more, preferably 2000 to 250,000. Is more preferable. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The acrylic resin 1 may be any of a random polymer, a block polymer, a graft polymer, and the like.

The acrylic resin 1 may be used alone or in combination of two or more. The content of the acrylic resin 1 is preferably 5 to 75% by mass, more preferably 10 to 70% by mass, with respect to the total solid content of the photosensitive layer, from the viewpoint of good image area strength and image formability. More preferably, it is -60 mass%.
The total content of the polymerizable compound and the acrylic resin 1 is preferably 80% by mass or less based on the total solid content of the photosensitive layer. If it exceeds 80% by mass, the sensitivity and developability may be lowered. More preferably, it is 35-75 mass%.
Although the specific example of the polymerization unit which comprises the acrylic resin 1 used for this invention below, and the specific example of the acrylic resin 1 are shown, this invention is not limited by these examples.

The acrylic resin 2 used for the photosensitive layer of the lithographic printing plate precursor according to the invention has an SP value of 19.0 to 21.5 (MPa) ^1/2 and an acid value of 0.3 meq / g or less.

The SP value means a solubility parameter (Solubility Parameter) and is known as a measure indicating the level of polarity of a substance. A large SP value indicates that the compound has high polarity, and a small SP value indicates that the compound has low polarity, and is also used for evaluation of solubility and compatibility. The SP value of the compound can be obtained by actual measurement or by estimation from the compound structural formula. As the measured value, for example, Handbook of Solubility Parameter and Other Cohesion Parameters 2 nd Ed., CRC Press Boca Roton Fla (1911), Polymer Handbook 4 th Ed., There is described, for example, in Wiely-Interscience (1999). The chemical structural formulas Properties of Polymers 3 The estimated from ^{rd Ed., Elsever (1990)} , Toshinao Okitsu, adhesive is described in such 246 Vol.38 (6) (1994) .
The SP value of the acrylic resin 2 is preferably 19.5 to 21.0 (MPa) ^{1/2 and} more preferably 19.7 to 20.8. If the SP value is less than 19.0, the developability may be inferior, and if the SP value is greater than 21.5, the printing durability may be inferior.

The acrylic resin 2 is preferably substantially free of an acid group such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group, and the acid value of the acrylic resin 2 is 0.3 meq / g or less, preferably 0. .1 meq / g or less. When the acid value exceeds 0.3 meq / g, problems such as deterioration in developability (generation of residual film) and reduction in printing durability due to increase in hydrophilicity may occur.
The acrylic resin 2 is preferably substantially insoluble in water and an aqueous solution having a pH of 10 or higher. The solubility of the acrylic resin 2 in water or an aqueous solution having a pH of 10 or higher (the acrylic resin concentration at the time of saturated dissolution) is preferably 1.0% by mass or less. The solubility measurement temperature is a normal temperature during plate-making development, and is 25 ° C. here.
By using the acrylic resin 2 as described above, the film strength, the water resistance and the inking property of the photosensitive layer are improved and the printing durability is improved while maintaining good developability with respect to the aqueous developer.

  The acrylic resin 2 can be obtained using a known acrylic monomer by adjusting the type and amount ratio of the monomer so as to have the characteristics (SP value, acid value, etc.) within the above range. As the acrylic monomer, for example, (meth) acrylic acid esters and crotonic acid esters (meth) acrylamides are preferable. Specific examples of such a monomer include the following compounds.

  Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, acetoxyethyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate , Cyclohexyl (meth) acrylate, benzyl (meth) acrylate, diethylene glycol monomethyl ether (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, diethylene glycol monophenyl ether (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, tri Ethylene glycol monoethyl ether (meth) acrylate, dipropylene glycol monomethyl ether (meth) acrylate, polyethylene glycol monomethyl ether (meth) acrylate, polypropylene glycol monomethyl ether (meth) acrylate, monomethyl copolymer of ethylene glycol and propylene glycol Ether (meth) acrylate, N, N-di Chill aminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate.

  Examples of the crotonic acid esters include butyl crotonic acid and hexyl crotonic acid.

Examples of (meth) acrylamides include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, Nn butylacryl (meth) amide, N-tert. Butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N -Phenyl (meth) acrylamide, N-benzyl (meth) acrylamide, (meth) acryloylmorpholine, etc. are mentioned.
An acrylic monomer having a urethane group or a urea group can also be used. Examples of such a compound include the following compounds.

In order to obtain an acrylic resin 2 having an acid value of 0.3 meq / g or less and an SP value of 19.0 to 21.5 (MPa) ^1/2 , an acrylic monomer having a non-acidic hydrophilic group is used. It is preferable to use it for a part of resin component.
Examples of hydrophilic groups include hydroxy groups, carboxylate groups, hydroxyethyl groups, ethyleneoxy groups, hydroxypropyl groups, amino groups, aminoethyl groups, aminopropyl groups, ammonium groups, amide groups, carboxymethyl groups, and the like. Polyether groups (diethylene oxide, triethylene oxide, polyethylene oxide, dipropylene oxide, tripropylene oxide, polypropylene oxide, ditetramethylene oxide, tritetramethylene oxide, polytetramethylene oxide, combinations thereof, etc.) It is preferable to use an acrylic monomer having such a hydrophilic group.

More specifically, R of the ester residue (—COOR) of (meth) acrylic acid ester is —CH ₂ CH ₂ O— unit, —CH ₂ CH (CH ₃ ) O— unit or —CH ₂ CH _2. Particularly preferred are resins containing at least one kind such as (meth) acrylic acid esters containing NH-units, hydroxyl group-containing (meth) acrylic acid esters, (meth) acrylamides and the like. Moreover, 5-70 mol% is preferable, as for the ratio of the acrylic monomer which has a hydrophilic group in the acrylic resin 2 of this invention, 10-60 mol% is more preferable, and 15-50 mol% is especially preferable. If the ratio of the acrylic monomer having a hydrophilic group is less than 5 mol%, the developability may be lowered, and if it exceeds 70 mol%, the printing durability may be lowered.
In addition, the acrylic resin 2 preferably has crosslinkability in order to further improve the film strength of the image area. In order to give the acrylic resin 2 crosslinkability, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced. The crosslinkable functional group may be introduced by copolymerization or may be introduced by a polymer reaction.

  Here, the crosslinkable group is a group that crosslinks the acrylic resin binder in the process of radical polymerization reaction that occurs in the photosensitive layer when the lithographic printing plate precursor is exposed. About such a crosslinkable group, the description regarding the crosslinkable group in the said acrylic resin 1 is applicable similarly.

  In the acrylic resin 2 having crosslinkability, for example, free radicals (polymerization initiating radicals or growth radicals in the polymerization process of the polymerizable compound) are added to the crosslinkable functional group, and the polymerization chain of the polymerizable compound directly or between the polymers. Addition polymerization is carried out to form a cross-link 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 acrylic resin 2 (content of the unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol, more preferably 1 g per 1 g of the acrylic resin 2. It is 1.0-7.0 mmol, Most preferably, it is 2.0-5.5 mmol. Even in the case of the acrylic resin 2 having these crosslinkable groups, it is necessary to satisfy the aforementioned characteristics (SP value, acid value, etc.).

 Although the example of the compound of the acrylic resin 2 which can be used conveniently for this invention is shown, if this invention satisfy | fills the above-mentioned characteristic, it will not be limited to these. In addition, the numerical value attached | subjected to each compound shows SP value.

  The glass transition temperature (Tg) of the acrylic resin 2 according to the present invention is preferably 0 to 150 ° C, more preferably 20 to 120 ° C, and particularly preferably 30 to 100 ° C. When the glass transition temperature is less than 0 ° C., the printing durability may be deteriorated, and when the glass transition temperature exceeds 150 ° C., the developability may be deteriorated.

The acrylic resin 2 preferably has a mass average molecular weight of 5,000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1,000 or more, preferably 2000 to 250,000. Is more preferable. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The acrylic resin 2 may be any of a random polymer, a block polymer, a graft polymer, and the like.

The acrylic resin 2 may be used alone or in combination of two or more.
The content of the acrylic resin 2 is preferably 5 to 75% by mass, more preferably 10 to 60% by mass, and more preferably 20 to 20% by mass with respect to the total solid content of the photosensitive layer, from the viewpoint of good image area strength and image formability. 50% by mass is particularly preferred.
Moreover, it is preferable that the total content of the said polymeric compound and the acrylic resin 2 is 80 mass% or less with respect to the total solid of a photosensitive layer. If it exceeds 80% by mass, the sensitivity and developability may be lowered. More preferably, it is 30-75 mass%.

(E) Chain transfer agent The photosensitive layer of the invention preferably contains a chain transfer agent. Chain transfer agents contribute to improved sensitivity and storage stability. As the compound that acts as a chain transfer agent, for example, a compound group having SH, PH, SiH, GeH in the molecule is used. These can donate hydrogen to low-activity radical species to generate radicals, or can be oxidized and then deprotonated to generate radicals.

In the photosensitive layer of the present invention, in particular, a thiol compound (for example, 2-mercaptobenzimidazoles) can be preferably used as a chain transfer agent.
Especially, the thiol compound represented by the following general formula (I) is used especially suitably. By using this thiol compound as a chain transfer agent, the problem of odor and sensitivity reduction due to evaporation from the photosensitive layer and diffusion to other layers are avoided, and it has excellent storage stability and high sensitivity and high printing durability. A lithographic printing plate precursor is obtained.

  In general formula (I), R represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and A represents a 5-membered ring having a carbon atom together with an N = CN moiety. Alternatively, it represents an atomic group that forms a 6-membered heterocycle, and A may further have a substituent.

  More preferably, those represented by the following general formula (IA) or general formula (IB) are used.

  In general formulas (IA) and (IB), R represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and X represents a halogen atom, an alkoxyl group or a substituent. The alkyl group which may have or the aryl group which may have a substituent is represented.

  Specific examples of the compound represented by formula (I) are shown below, but the present invention is not limited to these.

  The amount of the chain transfer agent such as thiol compound used is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, and still more preferably 1.0%, based on the total solid content of the photosensitive layer. -10 mass%.

<Microcapsule>
In the present invention, as a method for causing the photosensitive layer to contain the above-described photosensitive layer constituents and other constituents described later, for example, as described in JP-A Nos. 2001-277740 and 2001-277742, A part of the components can be encapsulated in microcapsules and added to the photosensitive layer. In that case, each component can be contained in any ratio in and out of the microcapsule.

  As a method for microencapsulating the photosensitive layer constituent components, known methods can be applied. For example, as a method for producing microcapsules, a method using coacervation found in US Pat. Nos. 2,800,547 and 2,800,498, each specification of US Pat. No. 3,287,154, Japanese Patent Publication No. 38-19574, 42-446 by the interfacial polymerization method, US Pat. No. 3,418,250, US Pat. No. 3,660,304 by precipitation of polymer, US Pat. No. 3,796,669, isocyanate polyol A method using a wall material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, and a urea-formaldehyde system found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802. Or urea formaldehyde-resorcino A method using a wall forming material, a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose, as shown in US Pat. No. 4,025,445, and Japanese Patent Publication Nos. 36-9163 and 51-9079. In situ method using monomer polymerization, spray drying method found in British Patent No. 930422, US Pat. No. 3,111,407, electrolytic dispersion cooling method seen in British Patent Nos. 952807 and 967074, etc. However, it is not limited to these.

  A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. Moreover, you may introduce | transduce into the microcapsule wall the compound which has crosslinkable functional groups, such as an ethylenically unsaturated bond which can be introduce | transduced into said binder polymer.

  The average particle size of the microcapsules 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.

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

<Surfactant>
In the present invention, it is preferable to use a surfactant in the photosensitive layer in order to promote 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 in the photosensitive layer of the invention is not particularly limited, and conventionally known nonionic surfactants 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 alkylamines, triethanolamine fatty acid ester, trialkylamine oxide, polyethylene glycol, copolymers of polyethylene glycol and polypropylene glycol.

  The anionic surfactant used in the photosensitive layer of the 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 alcohol 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 photosensitive layer of 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 photosensitive layer of the present invention is not particularly limited, and conventionally known ones can be used. Examples thereof include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric 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. Also preferred are the fluorosurfactants described in JP-A-62-170950, JP-A-62-226143 and JP-A-60-168144.

Among the surfactants, anionic surfactants and cationic surfactants are preferable from the viewpoint of developability.
The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 7% by mass with respect to the total solid content of the photosensitive layer.

<Hydrophilic polymer>
In the present invention, a hydrophilic polymer can be contained in order to improve the developability and the microcapsule dispersion stability.
Examples of the hydrophilic polymer include hydroxy group, carboxyl group, carboxylate group, hydroxyethyl group, polyoxyethyl group, hydroxypropyl group, polyoxypropyl group, amino group, aminoethyl group, aminopropyl group, ammonium group, Preferred examples include those having a hydrophilic group such as an amide group, carboxymethyl group, sulfonic acid group, and phosphoric acid group.

  Specific examples include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids and their salts, Polymethacrylic acids and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers and copolymers of hydroxypropyl acrylate, homopolymers of hydroxybutyl methacrylate Polymers and copolymers, homopolymers and copolymers of hydroxybutyl acrylate Polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide homopolymers and copolymers having a hydrolysis degree of 60 mol% or more, preferably 80 mol% or more , Homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide, polyvinylpyrrolidone, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, etc. Is mentioned.

The hydrophilic polymer preferably has a mass average molecular weight of 5000 or more, more preferably 10,000 to 300,000. The hydrophilic polymer may be any of a random polymer, a block polymer, a graft polymer, and the like.
The content of the hydrophilic polymer in the photosensitive layer is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total solid content of the photosensitive layer.

<Colorant>
In 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 (orientated chemistry) Industrial Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI451)
70B), malachite green (CI42000), methylene blue (CI52015) 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.

  These colorants are preferably added since the image portion and the non-image portion can be easily distinguished after image formation. The addition amount is preferably 0.01 to 10% by mass with respect to the total solid content of the photosensitive layer.

<Bakeout agent>
In the photosensitive layer of the present invention, a compound that changes color by an acid or a radical can be added in order to form a printout image. As such a compound, various dyes such as diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminoquinone, azo, and azomethine are effectively used.

Specific examples include brilliant green, ethyl violet, methyl green, crystal violet, basic fuchsin, methyl violet 2B, quinaldine red, rose bengal, methanyl yellow, thymol sulfophthalein, xylenol blue, methyl orange, paramethyl red, Congo Fred, Benzopurpurin 4B, α-Naphthyl Red, Nile Blue 2B, Nile Blue A, Methyl Violet, Malachide Green, Parafukusin, Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.], Oil Blue # 603 [Orient Chemical Kogyo Co., Ltd.], Oil Pink # 312 [Orient Chemical Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd.], Oil Scarlet # 308 [Orient Gaku Kogyo Co., Ltd.], Oil Red OG [Orient Chemical Co., Ltd.], Oil Red RR [Orient Chemical Co., Ltd.], Oil Green # 502 [Orient Chemical Co., Ltd.], Spiron Red BEH Special [made by Hodogaya Chemical Co., Ltd.], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p- Diethylaminophenyliminonaphthoquinone, 2-carboxystearylamino-4-pN, N-bis (hydroxyethyl) amino-phenyliminonaphthoquinone, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4- - dyes and p of diethylamino phenyl imino-5-pyrazolone, p ', p "- hexamethyl triamnotriphenylmethane (leuco crystal violet), and a leuco dye such as Pergascript Blue SRB (manufactured by Ciba-Geigy).

  In addition to the above, a leuco dye known as a material for thermal paper or pressure-sensitive paper is also suitable. Specific examples include crystal violet lactone, malachite green lactone, benzoylleucomethylene blue, 2- (N-phenyl-N-methylamino) -6- (Np-tolyl-N-ethyl) amino-fluorane, 2-anilino. -3-methyl-6- (N-ethyl-p-toluidino) fluorane, 3,6-dimethoxyfluorane, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) ) -Fluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane, 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane, 3 -(N, N-diethylamino) -6-methyl-7-xylidinofluorane, 3- (N, N-diethylamino) -6-methyl-7-chloro Fluorane, 3- (N, N-diethylamino) -6-methoxy-7-aminofluorane, 3- (N, N-diethylamino) -7- (4-chloroanilino) fluorane, 3- (N, N-diethylamino) -7-chlorofluorane, 3- (N, N-diethylamino) -7-benzylaminofluorane, 3- (N, N-diethylamino) -7,8-benzofluorane, 3- (N, N-dibutyl) Amino) -6-methyl-7-anilinofluorane, 3- (N, N-dibutylamino) -6-methyl-7-xylidinofluorane, 3-piperidino-6-methyl-7-anilinofluorane 3-pyrrolidino-6-methyl-7-anilinofluorane, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis (1-n-butyl- -Methylindol-3-yl) phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl- 2-methylindol-3-yl) -4-zaphthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, and the like.

  A suitable addition amount of the dye that changes color by acid or radical is 0.01 to 15% by mass relative to the solid content of the photosensitive layer.

<Thermal polymerization inhibitor>
In order to prevent unnecessary thermal polymerization of the radical polymerizable compound during the production or storage of the photosensitive layer, it is preferable to add a small amount of a thermal polymerization inhibitor to the photosensitive layer of the present invention.
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-t- (Butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt 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 photosensitive layer.

<Higher fatty acid derivatives>
In order to prevent polymerization inhibition by oxygen, a higher fatty acid derivative such as behenic acid or behenamide is added to the photosensitive layer of the present invention so that it is unevenly distributed on the surface of the photosensitive layer during the drying process after coating. May be. The amount of the higher fatty acid derivative added is preferably from about 0.1 to about 10% by weight based on the total solid content of the photosensitive layer.

<Plasticizer>
The photosensitive layer of the present invention may contain a plasticizer. Examples of the plasticizer include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diallyl phthalate; Glycol esters such as glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, triethylene glycol dicaprylate; Phosphate esters such as tricresyl phosphate and triphenyl phosphate Diisobutyl adipate, dioctyl adipate, dimethyl sebacate, dibutyl sebacate, dioct Ruazereto, aliphatic dibasic acid esters such as dibutyl maleate; polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, butyl laurate in. The plasticizer content is preferably about 30% by mass or less based on the total solid content of the photosensitive layer.

<Inorganic fine particles>
The photosensitive layer of the present invention may contain inorganic fine particles in order to improve the cured film strength of the image area. 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. Even if they are not photothermally convertible, they 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 size of 5 nm to 10 μm, and more preferably 0.5 to 3 μm. Within the above range, it is possible to form a non-image portion excellent in hydrophilicity that is stably dispersed in the photosensitive layer, sufficiently retains the film strength of the photosensitive layer, and does not easily cause 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 20% by mass or less, and more preferably 10% by mass or less, based on the total solid content of the photosensitive layer.

<Hydrophilic low molecular weight compound>
The photosensitive layer of the present invention can contain a hydrophilic low molecular weight compound for improving developability. Examples of the hydrophilic low-molecular compound include water-soluble organic compounds such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and the like, and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol, organic amines such as triethanolamine, diethanolamine monoethanolamine and salts thereof,
Organic sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid and their salts, organic phosphonic acids such as phenylphosphonic acid and their salts, organic carboxylic acids such as tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, amino acids Examples thereof include acids and salts thereof, and organic quaternary ammonium salts such as tetraethylamine hydrochloride.

In addition to the above, the photosensitive layer of the present invention can contain, for example, a cosensitizer. Sensitivity can be further improved by using a co-sensitizer. These mechanisms of action are not clear, but many are thought to be based on the following chemical processes. That is, a co-sensitizer reacts with various intermediate active species (radicals and cations) generated in the course of the photoreaction initiated by the polymerization initiator and the subsequent addition polymerization reaction to generate new active radicals. Estimated. These can be broadly divided into (a) those that can be reduced to generate active radicals, (b) those that can be oxidized to generate active radicals, and (c) radicals that are more active by reacting with less active radicals. Can be classified into those that act as chain transfer agents, but there is often no generality as to which of these individual compounds belong.

(A) Compound that is reduced to produce an active radical Compound having a carbon-halogen bond: It is considered that the carbon-halogen bond is reductively cleaved to generate an active radical. Specifically, for example, trihalomethyl-s-triazines and trihalomethyloxadiazoles can be preferably used.
Compound having nitrogen-nitrogen bond: It is considered that the nitrogen-nitrogen bond is reductively cleaved to generate an active radical. Specifically, hexaarylbiimidazoles and the like are preferably used.
Compound having oxygen-oxygen bond: It is considered that an oxygen-oxygen bond is reductively cleaved to generate an active radical. Specifically, for example, organic peroxides are preferably used.

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

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

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

(C) Compounds that react with radicals to convert to highly active radicals or act as chain transfer agents: For example, compounds having SH, PH, SiH, and GeH in the molecule are used. These can generate hydrogen by donating hydrogen to a low-activity radical species to generate radicals, or after being oxidized and deprotonated. Specific examples include 2-mercaptobenzimidazoles.
More specific examples of these co-sensitizers are described, for example, in JP-A-9-236913 as additives for the purpose of improving sensitivity, and these are also applied in the present invention. be able to.

<Formation of photosensitive layer>
The photosensitive layer of the present invention is formed by preparing or applying a coating solution by dispersing or dissolving the necessary components described above in a solvent. Solvents 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, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The photosensitive 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 repeatedly applying and drying a plurality of times.

The coating, the photosensitive layer coating amount on the support obtained after drying (solid content) may be varied according to the intended purpose, generally 0.3 to 3.0 g / m ² is preferred. Within this range, good sensitivity and good film properties of the photosensitive layer can be obtained.
Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

  The photosensitive layer of the lithographic printing plate precursor according to the present invention is obtained by subjecting the lithographic printing plate precursor to image exposure with a laser having a wavelength of 350 to 450 nm, and then using an automatic processor equipped with a rubbing member, in the presence of a developer having a pH of 2 to 10, By rubbing the plate surface with a rubbing member, the non-exposed portion is removed.

<Protective layer>
The lithographic printing plate precursor according to the invention is preferably provided with a protective layer (oxygen blocking layer) on the photosensitive layer in order to block diffusion and penetration of oxygen that hinders the polymerization reaction during exposure. The protective layer used in the present invention has an oxygen permeability A of 1.0 ≦ A ≦ 20 (mL / m ² · day) at 25 ° C. and 1 atm.
) Is preferable. When the oxygen permeability A is extremely low at less than 1.0 (mL / m ² · day), unnecessary polymerization reaction occurs at the time of production and raw storage, and unnecessary fogging and image streaking occur during image exposure. The problem that fatness arises arises. Conversely, when the oxygen permeability A exceeds 20 (mL / m ² · day) and is too high, the sensitivity is lowered. The oxygen permeability A is more preferably 1.5 ≦ A ≦ 12 (mL / m ² · day), and further preferably 2.0 ≦ A ≦ 10.0 (
mL / m ² · day). In addition to the oxygen permeability described above, the properties desired for the protective layer further do not substantially inhibit the transmission of light used for exposure, have excellent adhesion to the photosensitive layer, and are easy in the development process after exposure. It is desirable that it can be removed. The device concerning such a protective layer has been conventionally made, and is described in detail in US Pat. No. 3,458,311 and JP-B-55-49729.

  As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, vinyl alcohol / vinyl phthalate copolymer, vinyl acetate / vinyl are used. Examples include water-soluble polymers such as alcohol / vinyl phthalate copolymer, vinyl acetate / crotonic acid copolymer, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, polyacrylic acid, and polyacrylamide. Or they can be mixed. Of these, the use of polyvinyl alcohol as the main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability.

  The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. Specific examples of the polyvinyl alcohol include those having a hydrolysis degree of 71 to 100 mol% and a polymerization repeating unit in the range of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA- 420, PVA-613, L-8 and the like, and these can be used alone or in combination. In a preferred embodiment, the content of polyvinyl alcohol in the protective layer is 20 to 95% by mass, and more preferably 30 to 90% by mass.

  Moreover, well-known modified polyvinyl alcohol can also be used preferably. For example, various hydrophilic modification sites such as anion modification sites modified with anions such as carboxyl groups and sulfo groups, cation modification sites modified with cations such as amino groups and ammonium groups, silanol modification sites, and thiol modification sites are randomly selected. Polyvinyl alcohol having various degrees of polymerization, the anion-modified site, the cation-modified site, the silanol-modified site, the thiol-modified site, the alkoxyl-modified site, the sulfide-modified site, and the ester modification of vinyl alcohol and various organic acids. Examples thereof include polyvinyl alcohol having various polymerization degrees having various modified sites such as a site, an ester-modified site of the anion-modified site and alcohols, an epoxy-modified site, and the like.

  As a component used by mixing with polyvinyl alcohol, polyvinyl pyrrolidone or a modified product thereof is preferable from the viewpoint of oxygen barrier properties and development removability, and the content in the protective layer is 3.5 to 80% by mass, preferably 10 to 60%. It is 15 mass%, More preferably, it is 15-30 mass%.

  Components of the protective layer (selection of PVA, use of additives), coating amount, and the like are selected in consideration of fogging, adhesion, and scratch resistance in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of the PVA used (the higher the content of the unsubstituted vinyl alcohol unit in the protective layer), the thicker the film thickness, the higher the oxygen barrier property, which is advantageous in terms of sensitivity. The water-soluble polymer such as polyvinyl alcohol (PVA) may have a molecular weight in the range of 2000 to 10 million, preferably in the range of 20,000 to 3 million.

As another composition of the protective layer, glycerin, dipropylene glycol, etc. can be added in an amount corresponding to several mass% with respect to the water-soluble polymer to give flexibility. Also, sodium alkyl sulfate, sodium alkyl sulfonate Anionic surfactants such as: amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ether are added in an amount of several percent by mass relative to the water-soluble polymer. be able to.

  In addition, adhesion to the image area and scratch resistance are extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on an oleophilic photosensitive layer, film peeling due to insufficient adhesion tends to occur, and the peeled part causes defects such as poor film hardening due to inhibition of oxygen polymerization. On the other hand, various proposals have been made to improve the adhesion between these two layers. For example, in U.S. Patent Application No. 292,501 and U.S. Patent Application No. 44,563, an acrylic emulsion or a water-insoluble vinyl pyrrolidone-vinyl acetate copolymer is contained in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and laminating on a photosensitive layer. Any of these known techniques can be applied to the protective layer in the present invention. Such a coating method for the protective layer is described in detail in, for example, US Pat. No. 3,458,311 and Japanese Patent Publication No. 55-49729.

Furthermore, the protective layer in the lithographic printing plate precursor according to the invention preferably contains an inorganic stratiform compound for the purpose of improving oxygen barrier properties and photosensitive layer surface protection.
Here, the inorganic layered compound is a particle having a thin flat plate shape. For example, the following general formula A (B, C) _2-5 D ₄ O ₁₀ (OH, F, O) ₂
[However, A is any one of K, Na, and Ca, B and C are any of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. And mica groups such as natural mica and synthetic mica, talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by the formula 3MgO.4SiO.H ₂ O.

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

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

As the shape of the inorganic layered compound used in the present invention, from the viewpoint of diffusion control, the smaller the thickness, the better. The plane size is as long as it does not hinder the smoothness of the coated surface or the transmittance of actinic rays. Larger is better. Therefore, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  As for the particle diameter of the inorganic stratiform compound used in the present invention, the average major axis is 0.3 to 20 μm, preferably 0.5 to 10 μm, particularly preferably 1 to 5 μm. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. For example, among inorganic layered compounds, the size of the swellable synthetic mica that is a representative compound is about 1 to 50 nm in thickness and about 1 to 20 μm in surface size.

  When the inorganic layered compound particles having such a large aspect ratio are contained in the protective layer, the coating film strength is improved, and the permeation of oxygen and moisture can be effectively prevented. Deterioration is prevented, and even when stored for a long time under high-humidity conditions, the storage stability of the planographic printing plate precursor does not deteriorate due to changes in humidity, and the storage stability is excellent.

  It is preferable that content of the inorganic stratiform compound in a protective layer is 5/1-1/100 by mass ratio with respect to the quantity of the binder used for a protective layer. Even when a plurality of types of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-described mass ratio.

  Next, an example of a general dispersion method of the inorganic stratiform compound used for the protective layer will be described. First, 5 to 10 parts by mass of the swellable layered compound mentioned above as a preferred inorganic layered compound is added to 100 parts by mass of water, and the mixture is thoroughly swelled and swollen, and then dispersed by a disperser. Examples of the disperser used here include various mills that disperse mechanically by applying a direct force, a high-speed stirring disperser having a large shearing force, and a disperser that provides high-intensity ultrasonic energy. Specifically, ball mill, sand grinder mill, visco mill, colloid mill, homogenizer, tisol bar, polytron, homomixer, homo blender, ketdy mill, jet agitator, capillary emulsifier, liquid siren, electrostrictive ultrasonic generator, An emulsifying device having a Paulman whistle can be used. A dispersion of 5 to 10% by mass of the inorganic stratiform compound dispersed by the above method is highly viscous or gelled and has very good storage stability. When preparing a protective layer coating solution using this dispersion, it is preferably prepared by diluting with water and stirring sufficiently, and then blending with a binder solution.

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

  The protective layer coating solution thus prepared is applied onto the photosensitive layer provided on the support and dried to form a protective layer. The coating solvent can be appropriately selected in relation to the binder, but when a water-soluble polymer is used, it is preferable to use distilled water or purified water. The method for applying the protective layer is not particularly limited, and a known method such as the method described in US Pat. No. 3,458,311 or Japanese Patent Publication No. 55-49729 can be applied. . Specific examples of the protective layer include blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, and bar coating.

The coating amount of the protective layer is preferably in the range of 0.05 to 10 g / m ^{2 in} terms of the coating amount after drying. When the inorganic layered compound is contained, 0.1 to 0.5 g / More preferably in the range of m ² , 0.5 to 5 g when no inorganic layered compound is contained.
More preferably, it is in the range of / m ² .

[Support]
The support used in the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like hydrophilic support. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. 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 terms of refining technology, and therefore 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, and even more preferably from 0.2 to 0.3 mm.

  Prior to using the aluminum plate, it is preferable to perform a surface treatment such as roughening treatment or anodizing treatment. By the surface treatment, it becomes easy to improve hydrophilicity and secure adhesion between the photosensitive layer and the support. Prior to roughening the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like for removing rolling oil on the surface is performed as desired.

The surface roughening treatment of the aluminum plate is performed by various methods. For example, mechanical surface roughening treatment, electrochemical surface roughening treatment (surface roughening treatment for dissolving the surface electrochemically), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.

  The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and if desired, wear resistant. In order to increase the anodic oxidation treatment.

As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, an electrolyte concentration of 1 to 80% by mass solution, a liquid temperature of 5 to 70 ° C., a current density of 5 to 60 A / d m ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / m ^2, and more preferably 1.5 to 4.0 g / m ^2. Within this range, good printing durability and good scratch resistance of the non-image area of the lithographic printing plate can be obtained.

  As the support used in the present invention, the substrate having the above-mentioned surface treatment and having an anodized film may be used as it is, but for further improvement in adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation and the like. If necessary, it contains a micropore enlargement treatment, a micropore sealing treatment, and a hydrophilic compound described in Japanese Patent Application Laid-Open Nos. 2001-253181 and 2001-322365. A surface hydrophilization treatment immersed in an aqueous solution can be selected as appropriate. Of course, these enlargement processing and sealing processing are not limited to those described above, and any conventionally known method can be performed.

Sealing treatment includes vapor sealing, single treatment with zirconic fluoride, treatment with an aqueous solution containing an inorganic fluorine compound such as treatment with sodium fluoride, vapor sealing with addition of lithium chloride, sealing with hot water. Hole processing is also possible.
Of these, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and sealing treatment with hot water are preferable.

  The hydrophilization treatment is described in the specifications of US Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. There are such alkali metal silicate methods. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated. In addition, the treatment with potassium zirconate fluoride described in JP-B 36-22063, U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689, And a method of treating with polyvinylphosphonic acid as described in the specification of No. 272.

  When using a support having insufficient surface hydrophilicity, such as a polyester film, as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. As the hydrophilic layer, at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony, and a transition metal described in JP-A-2001-199175 A hydrophilic layer formed by coating a coating solution containing a colloid of oxide or hydroxide, or organic hydrophilicity obtained by crosslinking or pseudo-crosslinking an organic hydrophilic polymer described in JP-A-2002-79772 A hydrophilic layer having a hydrophilic matrix, a hydrophilic layer having an inorganic hydrophilic matrix obtained by sol-gel conversion comprising hydrolysis, condensation reaction of polyalkoxysilane, titanate, zirconate or aluminate, or a metal oxide A hydrophilic layer made of an inorganic thin film having a surface is preferred. Arbitrariness. Among these, a hydrophilic layer formed by applying a coating solution containing a silicon oxide or a hydroxide colloid is preferable.

  Moreover, when using a polyester film etc. as a support body of this invention, it is preferable to provide an antistatic layer in the hydrophilic layer side of a support body, the opposite side, or both sides. In the case where the antistatic layer is provided between the support and the hydrophilic layer, it also contributes to improving the adhesion with the hydrophilic layer. As the antistatic layer, a polymer layer in which metal oxide fine particles or a matting agent are dispersed as described in JP-A-2002-79772 can be used.

The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion to the photosensitive layer, good printing durability and good stain resistance can be obtained.
The color density of the support is preferably 0.15 to 0.65 as the reflection density value. Within this range, good image formability by preventing halation during image exposure and good plate inspection after development can be obtained.

(Undercoat layer)
In the lithographic printing plate precursor according to the invention, it is preferable to provide an undercoat layer of a compound containing a polymerizable group on a support. When an undercoat layer is used, the photosensitive layer is provided on the undercoat layer. The undercoat layer reinforces the adhesion between the support and the photosensitive layer in the exposed area, and easily peels the photosensitive layer from the support in the unexposed area, thereby improving the developability.
As the undercoat layer, specifically, a silane coupling agent having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679, JP-A-2-304441. The phosphorus compound etc. which have the ethylenic double bond reactive group of description are mentioned suitably. Particularly preferred compounds include compounds having a polymerizable group such as a methacryl group and an allyl group and a support-adsorptive group such as a sulfonic acid group, a phosphoric acid group and a phosphoric acid ester. A compound having a hydrophilicity-imparting group such as an ethylene oxide group in addition to the polymerizable group and the support-adsorbing group can also be exemplified as a suitable compound.
The coating amount (solid content) of the undercoat layer is preferably 0.1 to 100 mg / m ² ,
More preferably, it is 30 mg / m ² .

[Back coat layer]
After the surface treatment is performed on the support or after the undercoat layer is formed, a back coat can be provided on the back surface of the support, if necessary.
Examples of the back coat include hydrolysis and polycondensation of organic polymer compounds described in JP-A-5-45885, organometallic compounds or inorganic metal compounds described in JP-A-6-35174. A coating layer made of a metal oxide obtained in this manner is preferred. Among them, it is inexpensive to use a silicon alkoxy compound such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC ₄ H ₉ ) _4. It is preferable in terms of easy availability.

[Plate making method]
After the lithographic printing plate precursor in the present invention is image-exposed with a light source of 350 nm to 450 nm, the plate surface is rubbed with a rubbing member in the presence of a developer having a pH of 2 to 10 by an automatic developing machine. The photosensitive layer can be removed to form an image on the support surface. When the lithographic printing plate precursor has a protective layer, the protective layer is also removed at the same time.
Such processing in an automatic developing machine has an advantage that it is freed from dealing with development residue derived from the protective layer / photosensitive layer that occurs in the case of on-press development.

The developer 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. In particular, an aqueous solution having the same composition as that of a generally known fountain solution, a surfactant (anionic, nonionic, An aqueous solution containing a cationic system or the like, or an aqueous solution containing a water-soluble polymer compound is preferable. In particular, an aqueous solution containing both a surfactant and a water-soluble polymer compound is preferable. The pH of the developer is preferably 3-8, more preferably 4-7.
When an acidic to neutral developer is used, it is preferable to contain either an organic acid or an inorganic acid. By containing an organic acid or an inorganic acid, developability can be improved during plate making, and it is possible to suppress the occurrence of stains in the non-image area of the plate that has been made.

Examples of the anionic surfactant used in the developer of the present invention include fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid salts, linear alkyl benzene sulfonic acid salts, and branched alkyl benzene sulfonic acid. Acid salts, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium, N-alkyl sulfosuccinic acid monoamide disodium salts, petroleum Sulfonates, sulfated castor oil, sulfated beef tallow oil, sulfate esters of fatty acid alkyl esters, alkyl sulfate esters, polyoxyethylene alkyl ether sulfate esters, Fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates , Partially saponified products of styrene-maleic anhydride copolymer, partially saponified products of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensate and the like. Among these, dialkyl sulfosuccinates, alkyl sulfate esters and alkyl naphthalene sulfonates are particularly preferably used.

  The cationic surfactant used in the developer of the present invention is not particularly limited, and conventionally known ones can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.

Nonionic surfactants used in the developer of the present invention include polyethylene glycol type higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide adduct, polyhydric alcohol fatty acid ester ethylene oxide adduct, higher Alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, oil and fat ethylene oxide adducts, polypropylene glycol ethylene oxide adducts, dimethylsiloxane-ethylene oxide block copolymers, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymers, etc. , Fatty acid ester of glycerol of polyhydric alcohol type, fatty acid ester of pentaerythritol, sorbitol and Fatty acid esters of Rubitan, fatty acid esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines.
These nonionic surfactants may be used alone or in admixture of two or more. In the present invention, ethylene oxide adduct of sorbitol and / or sorbitan fatty acid ester, polypropylene glycol ethylene oxide adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymer, polyhydric alcohol Fatty acid esters are more preferred.

Further, from the viewpoint of stable solubility or turbidity in water, the nonionic surfactant used in the developer of the present invention is HLB (Hydrophile-Lipophile).
The (Balance) value is preferably 6 or more, and more preferably 8 or more. Furthermore, the ratio of the nonionic surfactant contained in the developer is preferably 0.01 to 10% by mass, and more preferably 0.01 to 5% by mass.
Also, acetylene glycol-based and acetylene alcohol-based oxyethylene adducts, fluorine-based and silicon-based surfactants can be used in the same manner.
As the surfactant used in the developer of the present invention, a nonionic surfactant is particularly suitable from the viewpoint of foam suppression.

Examples of the water-soluble polymer compound used in the developer of the present invention include soybean polysaccharide, modified starch, gum arabic, dextrin, fibrin derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, pullulan. , Polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone, polyacrylamide and acrylamide copolymer, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, styrene / maleic anhydride copolymer, etc. It is done.

  A well-known thing can be used for the said soybean polysaccharide, for example, there exists a brand name Soya Five (made by Fuji Oil Co., Ltd.) as a commercial item, and the thing of various grades can be used. What can be preferably used is one in which the viscosity of a 10% by mass aqueous solution is in the range of 10 to 100 mPa / sec.

  As the modified starch, known ones can be used, and starch such as corn, potato, tapioca, rice and wheat is decomposed with acid or enzyme in the range of 5 to 30 glucose residues per molecule, and further in an alkali. It can be made by a method of adding oxypropylene or the like.

Two or more water-soluble polymer compounds can be used in combination. The content of the water-soluble polymer compound in the developer is preferably from 0.1 to 20% by mass, and more preferably from 0.5 to 10% by mass.

  Further, the developer of the present invention may contain an organic solvent. Examples of the organic solvent that can be contained include aliphatic hydrocarbons (hexane, heptane, “Isopar E, H, G” (manufactured by Esso Chemical Co., Ltd.) or gasoline, kerosene, etc.), and aromatic hydrocarbons (toluene). , Xylene, etc.), halogenated hydrocarbons (methylene dichloride, ethylene dichloride, tricrene, monochlorobenzene, etc.) and polar solvents.

  Polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene glycol monomethyl ether, 2-ethoxyethanol, diethylene glycol monoethyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether , Propylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polypropylene glycol, tetraethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monobenzyl ether, ethylene glycol monophenyl ether, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol, etc.) , (Acetone, methyl ethyl ketone, ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), esters (ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, methyl lactate, butyl lactate, ethylene glycol monobutyl acetate, propylene Glycol monomethyl ether acetate, diethylene glycol acetate, diethyl phthalate, butyl levulinate, etc.) and others (triethyl phosphate, tricresyl phosphate, N-phenylethanolamine, N-phenyldiethanolamine, etc.).

  If the organic solvent is insoluble in water, it can be used after being solubilized in water using a surfactant or the like. If the developer contains an organic solvent, safety, ignition, From the viewpoint of property, the concentration of the solvent is preferably less than 40% by mass.

  In addition to the above, the developer of the present invention may contain a preservative, a chelate compound, an antifoaming agent, an organic acid, an inorganic acid, an inorganic salt, and the like.

Preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzisothiazolin-3-one, benztriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, pyridine, Derivatives such as quinoline and guanidine, diazine, triazole derivatives, oxazole, oxazine derivatives, nitrobromoalcohol-based 2-bromo-2-nitropropane-1,3diol, 1,1-dibromo-1-nitro-2-ethanol, 1,1-dibromo-1-nitro-2-propanol and the like can be preferably used.

  Examples of the chelate compound include ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, potassium salt thereof, sodium salt thereof, hydroxyethylethylenediaminetriacetic acid Nitrilotriacetic acid, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri (methylenephosphonic acid), potassium salt, sodium salt And organic phosphonic acids and phosphonoalkanetricarboxylic acids. Organic amine salts are also effective in place of the sodium and potassium salts of the chelating agents.

As the antifoaming agent, a general silicon-based self-emulsifying type, emulsifying type, or nonionic surfactant having a HLB of 5 or less can be used. Silicon antifoaming agents are preferred.
Among them, emulsification dispersion type and solubilization can be used.

  Examples of organic acids include citric acid, acetic acid, succinic acid, malonic acid, salicylic acid, caprylic acid, tartaric acid, malic acid, lactic acid, levulinic acid, p-toluenesulfonic acid, xylenesulfonic acid, phytic acid, and organic phosphonic acid. . The organic acid can also be used in the form of its alkali metal salt or ammonium salt.

  Examples of inorganic acids and inorganic salts include phosphoric acid, metaphosphoric acid, primary ammonium phosphate, secondary ammonium phosphate, primary sodium phosphate, secondary sodium phosphate, primary potassium phosphate, secondary potassium phosphate, Examples include sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium sulfite, ammonium sulfite, sodium hydrogen sulfate, nickel sulfate and the like.

  The developer described above can be used as a developer and developer replenisher for the exposed negative lithographic printing plate precursor, and is preferably applied to an automatic processor described later. When developing using an automatic processor, the developing solution becomes fatigued according to the amount of processing, so the processing capability may be restored using a replenisher or a fresh developer. This replenishing method is also preferably applied to the lithographic printing plate making method of the present invention.

  The development treatment with an aqueous solution having a pH of 2 to 10 in the present invention can be preferably carried out by an automatic processor equipped with a developer supply means and a rubbing member. As an automatic processor, for example, an automatic processor described in JP-A-2-220061 and JP-A-60-59351, which performs a rubbing process while transporting a lithographic printing plate precursor after image recording, or a cylinder Examples thereof include an automatic processor described in US Pat. Nos. 5,148,746, 5,568,768 and British Patent 2,297,719, which rub the lithographic printing plate precursor after image recording set thereon while rotating a cylinder. Among these, an automatic processor using a rotating brush roll as the rubbing member is particularly preferable.

The rotating brush roll that can be preferably used in the present invention can be appropriately selected in consideration of the difficulty of scratching the image area and the stiffness of the support of the lithographic printing plate precursor. As the rotating brush roll, a known one formed by planting a brush material on a plastic or metal roll can be used. For example, as described in Japanese Patent Application Laid-Open No. 58-159533, Japanese Patent Application Laid-Open No. 3-100554, or Japanese Utility Model Publication No. 62-167253, metal or plastic in which brush materials are implanted in rows. A brush roll can be used in which the groove mold material is radially wound around a plastic or metal roll as a core without a gap.
The brush material includes plastic fibers (for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6.6 and nylon 6.10, polyacrylonitrile, poly (meth) acrylate, etc. Acrylic and polyolefin synthetic fibers such as polypropylene and polystyrene) can be used. For example, the fiber has a hair diameter of 20 to 400 μm and a hair length of 5 to 30 mm. Can be used.
Furthermore, the outer diameter of the rotating brush roll is preferably 30 to 200 mm, and the peripheral speed at the tip of the brush rubbing the plate surface is preferably 0.1 to 5 m / sec.
Moreover, it is preferable to use two or more rotating brush rolls.

  The rotating direction of the rotating brush roll used in the present invention may be the same or opposite to the conveying direction of the planographic printing plate precursor of the present invention. Thus, when two or more rotating brush rolls are used, it is preferable that at least one rotating brush roll rotates in the same direction and at least one rotating brush roll rotates in the opposite direction. This further ensures the removal of the heat sensitive layer in the non-image area. Furthermore, it is also effective to swing the rotating brush roll in the direction of the rotation axis of the brush roll.

  Although the temperature of the developer can be used at any temperature, it is preferably 10 ° C to 50 ° C.

  In the present invention, the lithographic printing plate after the rubbing treatment can be optionally washed with water, dried and desensitized. In the desensitizing treatment, a known desensitizing solution can be used.

In addition, as the plate-making process of the lithographic printing plate from the lithographic printing plate precursor according to the present invention, the entire surface may be heated before exposure, during exposure, and between exposure and development, if necessary. Such heating promotes an image forming reaction in the photosensitive layer, and may have advantages such as improvement of sensitivity and printing durability and stabilization of sensitivity. Further, for the purpose of improving the image strength and printing durability, it is also effective to subject the developed image to full post heating or full exposure. Usually, the heating before development is preferably performed under a mild condition of 150 ° C. or less. If the temperature is too high, problems such as covering up to the non-image area occur. Very strong conditions are used for heating after development. Usually, it is the range of 200-500 degreeC. If the temperature is low, sufficient image strengthening action cannot be obtained. If the temperature is too high, problems such as deterioration of the support and thermal decomposition of the image area occur.

The plate making process will be further described in detail.
In the present invention, as described above, the development treatment may be performed immediately after the exposure step, but a heat treatment step may be provided between the exposure step and the development step. This heat treatment has the effect of improving the printing durability and further improving the uniformity of the image curing degree within the plate surface, and the conditions can be appropriately set within the range where these effects are present. Examples of the heating means include a conventional convection oven, an IR irradiation device, an IR laser, a microwave device, a Wisconsin oven, and the like. For example, it can be carried out by holding the plate surface temperature in the range of 70 to 150 ° C. for 1 second to 5 minutes. Preferably, the temperature is 80 ° C to 140 ° C for 5 to 1 minute, more preferably 90 ° C to 130 ° C for 10 to 30 seconds. This range is preferable in that the above effect can be obtained efficiently and there is no adverse effect such as deformation of the printing plate due to heat.
In the present invention, a development processing step is performed after the above-described exposure step and preferably the heat treatment step to obtain a lithographic printing plate. The plate setter used in the exposure process, the heat treatment means used in the heat treatment, and the developing device used in the development process are preferably connected to each other and automatically continuously processed. Specifically, it is a plate making line in which a plate setter and a developing device are coupled by a conveying means such as a conveyor. A heat treatment unit may be provided between the plate setter and the developing device, and the heating unit and the developing device may be integrated.

When the printing plate to be used is easily affected by ambient light in the work environment, it is preferable that the plate making line is shielded by a filter or a cover.
After the image formation as described above, the entire surface may be exposed with an actinic ray such as ultraviolet light to accelerate the curing of the image portion. Examples of the light source for the entire surface exposure include a carbon arc lamp, a mercury lamp, a gallium lamp, a metal halide lamp, a xenon lamp, a tungsten lamp, and various laser lights. Furthermore, in order to obtain sufficient printing durability, the overall exposure amount is preferably at least 10 mJ / cm ² or more, more preferably 100 mJ / cm ² or more.
Heating may be performed simultaneously with the entire surface exposure, and further improvement in printing durability is recognized by heating. Examples of the heating device include a conventional convection oven, an IR irradiation device, an IR laser, a microwave device, and a Wisconsin oven. At this time, the plate surface temperature is preferably 30 to 150 ° C, more preferably 35 to 130 ° C, and still more preferably 40 to 120 ° C.

Prior to the above development processing, the lithographic printing plate precursor is exposed imagewise by laser exposure through a transparent original image having a line image, a halftone dot image or the like, or by laser beam scanning by digital data.
A desirable wavelength of the light source is 350 nm to 450 nm, and specifically, an InGaN semiconductor laser is suitable. The exposure mechanism may be any of an internal drum system, an external drum system, a flat bed system, and the like.

As available laser light sources of 350 nm to 450 nm, the following can be used.
As a gas laser, an Ar ion laser (364 nm, 351 nm, 10 mW to 1 W), a Kr ion laser (356 nm, 351 nm, 10 mW to 1 W), a He—Cd laser (441 nm, 325 nm, 1 mW to 100 mW), and a solid laser as Nd: YAG (YVO ₄ ) and SHG crystal × 2 combinations (355 nm, 5 mW to 1 W), Cr: LiSAF and SHG crystal combination (430 nm, 10 mW), as a semiconductor laser system, KNbO ₃ ring resonator (430 nm, 30 mW), Combination of waveguide type wavelength conversion element and AlGaAs / InGaAs semiconductor (380 nm to 450 nm, 5 mW to 100 mW), combination of waveguide type wavelength conversion element and AlGaInP, AlGaAs semiconductor (300 nm to 350 nm, 5 mW to 100 mW) ), AlGaInN (350 nm to 450 nm, 5 mW to 30 mW), N ₂ laser (337 nm, pulse 0.1 to 10 mJ), XeF (351 nm, pulse 10 to 250 mJ) as a pulse laser. In particular, an AlGaInN semiconductor laser (commercially available InGaN-based semiconductor laser 400 to 410 nm, 5 to 30 mW) is preferable in terms of wavelength characteristics and cost.

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

       X · S = n · q · t (eq 1)

i) In the case of the internal drum (single beam) system, the laser rotation speed f (radians / s), the sub-scanning length Lx (cm) of the photosensitive material, the resolution Z (dots / cm), and the total exposure time t (s) In general, equation (eq 2) holds.

       f · Z · t = Lx (eq 2)

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

       F.Z.n.t = Lx (eq 3)

iii) Flat head (multi-beam) system Polygon mirror rotation speed H (radians / s), photosensitive material sub-scanning length Lx (cm), resolution Z (dots / cm), total exposure time t (s), Equation (eq 4) is generally established between the number of beams (n).

       F.Z.n.t = Lx (eq 4)

Resolution (2560 dpi) required for the actual printing plate, plate size (A1 / B1, sub-scan length 42 inch), exposure conditions of about 20 sheets / hour and photosensitive characteristics of the planographic printing plate precursor of the present invention (photosensitive wavelength, By substituting (sensitivity: about 0.1 mJ / cm ² ) into the above formula, it is understood that a combination with a multi-beam exposure method using a laser having a total output of 20 mW or more is particularly preferable in the planographic printing plate precursor of the present invention. it can. Further, by combining operability, cost, etc., a combination with an external drum type semiconductor laser multi-beam (10 or more) exposure apparatus is most preferable.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
[Synthesis of acrylic resin binder polymer]

Synthesis Example 1: Synthesis of binder polymer P-3 70 g of 1-methoxy-2-propanol was placed in a three-necked flask equipped with a condenser and a stirrer and heated to 70 ° C. Under a nitrogen stream, 12.0 g of methyl methacrylate 12.0 g, allyl methacrylate 5.1 g, Bremer PME100 (trade name: manufactured by Nippon Oil & Fats Co., Ltd.) 7.25, V-65 (trade name: manufactured by Wako Pure Chemical Industries, Ltd.) 1 A solution dissolved in 70 g of -methoxy-2-propanol was added dropwise over 2.5 hours. The mixture was further reacted at 70 ° C. for 2 hours. Next, the reaction solution was poured into water to precipitate a copolymer. This was collected by filtration, washed and dried to obtain an exemplary binder polymer P-3. The average molecular weight was measured by gel permeation chromatography (GPC) using polystyrene as a standard substance, and the result was 60,000.
Exemplified binder polymers P-4, P-11, P-14, and P-90 were synthesized in the same manner as in Synthesis Example 1.

Synthesis Example 2: Synthesis of binder polymer P-22 In a three-necked flask equipped with a condenser and a stirrer, 80 g of N-methylpyrrolidone was placed and heated to 75 ° C. Under a nitrogen stream, 12 g of methyl methacrylate, 11.05 g of Blemmer PME200 (trade name: manufactured by NOF Corporation), 11.2 g of the following compound A, 0.46 g of V-601 (trade name: manufactured by Wako Pure Chemical Industries), N-methyl A solution dissolved in 80 g of pyrrolidone was added dropwise over 2.5 hours. The mixture was further reacted at 75 ° C. for 2 hours. After this solution was cooled to room temperature, 0.07 g of 4-hydroxy-TEMPO and 15 g of DBU were added. After stirring for 30 minutes, the mixture was allowed to stand overnight. Next, the reaction solution was poured into water to precipitate a copolymer. This was collected by filtration, washed and dried to obtain an exemplary binder polymer P-22. As a result of measuring the average molecular weight by gel permeation chromatography (GPC) using polystyrene as a standard substance, it was 80,000.
In the same manner as in Synthesis Example 2, the exemplified binder polymers P-21, P-27, P-35, P-40, P-47, P-57, P-63, P-71, P-73, P- 74, P-77, P-79, P-85, P-86, P-93, P-94, P-109, and P-110 were synthesized.

(Production of support)
In order to remove rolling oil on the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm, a degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution. The aluminum surface was grained using three bundle-planted nylon brushes 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 a 20 mass% nitric acid aqueous solution 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 nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power source waveform is electrochemical roughening treatment using a trapezoidal rectangular wave alternating current with a time ratio TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave alternating current. Went. 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, nitric acid electrolysis was performed with an aqueous solution of 0.5% by mass hydrochloric acid (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. under the condition of an electric quantity of 50 C / dm ² when the aluminum plate was the anode. In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying. The plate was provided with a DC anodized film of 2.5 g / m ² at a current density of 15 A / dm ² using a 15% by mass sulfuric acid aqueous solution (containing 0.5% by mass of aluminum ions) as an electrolyte, then washed with water and dried. .
The centerline average roughness Ra (JIS B0601) of the surface of the support thus obtained was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.

Further, the following undercoat liquid (1) was bar-coated and then oven-dried at 80 ° C. for 10 seconds to prepare a support having an undercoat layer having a dry coating amount of 10 mg / m ² .

<Undercoat liquid (1)>
・ Undercoat compound (1) 0.017 g
・ Methanol 9.00 g
・ Water 1.00g

[Preparation of lithographic printing plate precursor (1)]
A photosensitive layer coating solution (1) having the following composition was bar coated on the support provided with the undercoat layer, followed by oven drying at 70 ° C. for 60 seconds, and a photosensitive layer having a dry coating amount of 1.1 g / m ² . A protective layer coating solution (1) having the following composition was applied thereon using a bar, and then dried at 125 ° C. for 70 seconds to form a protective layer having a dry coating amount of 0.75 g / m ^2. A lithographic printing plate precursor (1) was obtained.

<Photosensitive layer coating solution (1)>
・ Binder polymer P-3 0.54g
・ Polymerizable compound 0.40g
Isocyanuric acid EO-modified triacrylate (manufactured by Toa Gosei Co., Ltd., Aronix M-315)
・ Polymerizable compound Ethoxylated trimethylolpropane triacrylate 0.08 g
(Nippon Kayaku Co., Ltd., SR9035, EO addition mole number 15, molecular weight 1000)
・ The following sensitizing dye (1) 0.06 g
・ The following polymerization initiator (1) 0.18 g
・ The following chain transfer agent (1) 0.07 g
・ 0.40 g of ε-phthalocyanine pigment dispersion
(Pigment: 15 parts by mass, dispersant Binder polymer (P-3): 10 parts by mass, solvent cyclohexanone / methoxypropyl acetate / 1-methoxy-2-propanol = 15 parts by mass / 20 parts by mass / 40 parts by mass)
・ Thermal polymerization inhibitor 0.01g
N-nitrosophenylhydroxylamine aluminum salt-The following fluorosurfactant (1) 0.001 g
・ Polyoxyethylene-polyoxypropylene condensate 0.04g
(Asahi Denka Kogyo Co., Ltd., Pluronic L44)
・ Tetraethylamine hydrochloride 0.01g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

Protective layer coating solution (1)
Polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 500) 40 g
Polyvinylpyrrolidone (molecular weight 50,000) 5g
Poly (vinyl pyrrolidone / vinyl acetate (1/1)) (molecular weight 70,000) 0.5g
Surfactant (Emalex 710, manufactured by Nippon Emulsion Co., Ltd.) 0.5g
950g of water

[Preparation of lithographic printing plate precursors (2) to (24) and comparative lithographic printing plate precursors (1) to (4)]
A lithographic printing plate except that the binder polymer P-3 of the photosensitive layer coating solution (1) is replaced with binder polymers P-4 to P-110 and comparative binder polymers P-121 to P-124 shown in Table A below. In the same manner as the original plate (1), lithographic printing plate precursors (2) to (24) and comparative lithographic printing plate precursors (1) to (4) were obtained.
The binder polymers P-4 to P-110 in Table A are those exemplified above, and the comparative binder polymers P-121 to P-124 are those shown in Table B.

[Preparation of lithographic printing plate precursor (25)]
A lithographic printing plate precursor (25) was obtained in the same manner as in the production of the lithographic printing plate precursor (1) except that the photosensitive layer coating solution (1) was changed to a photosensitive layer coating solution (2) having the following composition.

<Photosensitive layer coating solution (2)>
・ 0.2 g of the above polymerization initiator (1)
・ Sensitizing dye (1) 0.1 g
・ Binder polymer P-74 3.0g
-Polymerizable compound 6.2g
Isocyanuric acid EO-modified diacrylate (Aronix M-215 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 0.2g
・ 0.1 g of the above fluorosurfactant (1)
・ The following microcapsule dispersion 25.0 g
・ Methyl ethyl ketone 35.0g
・ 3-methoxy-2-propanol 35.0 g

(Microcapsule dispersion)
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemical Co., Ltd., Takenate D-110N) 10 g, isocyanuric acid EO-modified diacrylate (Toa Gosei Co., Ltd. Aronix M-215) 4.15 g and 0.1 g of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by 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 12000 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 3 hours. The microcapsule liquid thus obtained was diluted with distilled water to a solid content concentration of 20% by mass to obtain a microcapsule dispersion. The average particle size of the microcapsules was 0.25 μm.

[Examples 1 to 25 and Comparative Examples 1 to 4]
(1) Exposure, development and printing For each of the above lithographic printing plate precursors (1) to (25) and comparative lithographic printing plate precursors (1) to (4), the energy density was determined using a 405 nm semiconductor laser with an output of 100 mW. The imagewise exposure was performed with a change.
Thereafter, the developing solution (1) having the following composition was used, and development processing was carried out with an automatic developing processor having a structure shown in FIG. The pH of the developer was 4.6. The automatic developing processor is an automatic processor having two rotating brush rolls. As the rotating brush roll, the first brush roll is made of polybutylene terephthalate fiber (hair diameter: 200 μm, hair length: 17 mm). Using a brush roll with an outer diameter of 90 mm implanted with 200 mm / min in the same direction as the conveying direction (peripheral speed 0.94 m / sec at the tip of the brush), the second brush roll is made of polybutylene terephthalate Using a brush roll having an outer diameter of 60 mm in which fibers (hair diameter: 200 μm, hair length: 17 mm) were implanted, it was rotated 200 times per minute in the direction opposite to the conveying direction (peripheral speed of the brush tip: 0.63 m / sec). . The planographic printing plate precursor was transported at a transport speed of 100 cm / min.
The developer was showered from the spray pipe with a circulation pump and supplied to the plate surface. The tank capacity of the developer was 10 liters.

Developer (1)
・ Water 100g
・ Benzyl alcohol 1g
・ Polyoxyethylene naphthyl ether 1g
(Average number of oxyethylene n = 13)
・ Dioctyl sulfosuccinate sodium salt 0.5g
・ 1g gum arabic
・ Ethylene glycol 0.5g
・ Primary ammonium phosphate 0.05g
・ Citric acid 0.05g
・ Ethylenediaminetetraacetate tetrasodium salt 0.05g

  Subsequently, the developed lithographic printing plate is attached to a printing machine SOR-M manufactured by Heidelberg, and dampening water (EU-3 (Etchi solution manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol = 1/89/10. (Capacity ratio)) and TRANS-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.) were used for printing at a printing speed of 6000 sheets per hour.

(2) Evaluation The developability and printing durability of the lithographic printing plate precursor were evaluated as follows. The results are shown in Table C.
<Developability>
The lithographic printing plate precursor was exposed and developed as described above, the non-image area of the obtained lithographic printing plate was visually confirmed, and the presence or absence of the remaining photosensitive layer was evaluated according to the following criteria.
○: No residual film, △: Slightly residual film, ×: Residual film <Print durability>
When printing was performed as described above, as the number of printed sheets increased, the image area gradually worn out and the ink acceptability decreased, so the ink density in the printing paper decreased. 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.

  As is apparent from the results shown in Table C, the lithographic printing plate precursor using the specific acrylic resin of the present invention as a binder polymer for the photosensitive layer is excellent in both developability and printing durability. On the other hand, a comparative lithographic printing plate precursor using a binder polymer outside the scope of the present invention for the photosensitive layer is inferior in developability or printing durability.

Example 26
Within 30 seconds after the image exposure, the lithographic printing plate precursor was placed in an oven, hot air was blown to heat the entire surface of the lithographic printing plate precursor, and held at 110 ° C. for 15 seconds. Thereafter, exposure, development, printing and evaluation were performed in the same manner as in Example 1 except that the same development treatment as in Example 1 was performed within 30 seconds. By heat treatment, developability was good and printing durability was 52,000 sheets.

Example 27
The lithographic printing plate precursor (1) was subjected to image exposure using a violet semiconductor laser plate setter Vx9600 (equipped with InGaN semiconductor laser 405 nm ± 10 nm emission / output 30 mW) manufactured by FUJIFILM Electronic Imaging Ltd. The image was drawn using a FM screen (TAFFETA 20) manufactured by Fuji Photo Film Co., Ltd. with a resolution of 2438 dpi, and a 35% flat screen was drawn with a plate exposure of 0.09 mJ / cm ² . Within 30 minutes after image exposure of the exposed lithographic printing plate precursor, development processing was carried out using an automatic processor LP1250PLX manufactured by Fuji Photo Film Co., Ltd. The automatic processor is configured in the order of heating unit / washing unit / developing unit / rinsing unit / finishing unit. The heating condition of the heating unit is 100 ° C. for 10 seconds, and the washing unit, developing unit, rinsing unit All the baths in the unit / finishing unit were charged with the developer (1). The temperature of the developer was 28 ° C., and the planographic printing plate was transported at a transport speed of 110 cm / min.
After development, the non-image area and the image of the lithographic printing plate were visually confirmed. As a result, the photosensitive layer did not remain in the non-image area, and a uniform flat net image without unevenness was formed. Further, this lithographic printing plate was printed under the above printing conditions. The developability was ○, and the printing durability was 52,000 sheets.

[Preparation of lithographic printing plate precursor (26)]
A lithographic printing plate precursor (26) was obtained in the same manner as in the production of the lithographic printing plate precursor (1) except that the photosensitive layer coating solution (1) was changed to a photosensitive layer coating solution (3) having the following composition.

<Photosensitive layer coating solution (3)>
-0.54g of the following binder polymer (1)
・ Polymerizable compound 0.40g
Isocyanuric acid EO-modified triacrylate (manufactured by Toa Gosei Co., Ltd., Aronix M-315)
・ Polymerizable compound Ethoxylated trimethylolpropane triacrylate 0.08 g
(Nippon Kayaku Co., Ltd., SR9035, EO addition mole number 15, molecular weight 1000)
-0.06 g of the above sensitizing dye (1)
・ The above polymerization initiator (1) 0.18 g
・ The chain transfer agent (1) 0.07 g
・ 0.40 g of ε-phthalocyanine pigment dispersion
(Pigment: 15 parts by mass, dispersant Binder polymer (1): 10 parts by mass, solvent cyclohexanone / methoxypropyl acetate / 1-methoxy-2-propanol = 15 parts by mass / 20 parts by mass / 40 parts by mass)
・ Thermal polymerization inhibitor 0.01g
N-nitrosophenylhydroxylamine aluminum salt-Fluorosurfactant (1) 0.001 g
・ Polyoxyethylene-polyoxypropylene condensate 0.04g
(Asahi Denka Kogyo Co., Ltd., Pluronic L44)
・ Tetraethylamine hydrochloride 0.01g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

[Preparation of planographic printing plate precursors (27) to (36)]
The binder polymer (1) of the photosensitive layer coating solution (3) is changed to the following binder polymer (2) to
The lithographic printing plate precursors (27) to (36) were obtained in the same manner as the lithographic printing plate precursor (26) except that each of them was replaced with (11).

[Preparation of lithographic printing plate precursor (37)]
A lithographic printing plate precursor (37) was obtained in the same manner as in the production of the lithographic printing plate precursor (26) except that the photosensitive layer coating solution (3) was changed to a photosensitive layer coating solution (4) having the following composition.

<Photosensitive layer coating solution (4)>
・ 0.2 g of the above polymerization initiator (1)
・ Sensitizing dye (1) 0.1 g
・ 3.0 g of the above binder polymer (2)
-Polymerizable compound 6.2g
Isocyanuric acid EO-modified diacrylate (Aronix M-215 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 0.2g
・ 0.1 g of the above fluorosurfactant (1)
・ The following microcapsule dispersion 25.0 g
・ Methyl ethyl ketone 35.0g
・ 3-methoxy-2-propanol 35.0 g

(Microcapsule dispersion)
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemical Co., Ltd., Takenate D-110N) 10 g, isocyanuric acid EO-modified diacrylate (Toa Gosei Co., Ltd. Aronix M-215) 4.15 g and 0.1 g of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by 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 12000 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 3 hours. The microcapsule liquid thus obtained was diluted with distilled water to a solid content concentration of 20% by mass to obtain a microcapsule dispersion. The average particle size of the microcapsules was 0.25 μm.

[Examples 28 to 35 and Comparative Examples 5 to 8]
(1) Exposure, development and printing For each of the above lithographic printing plate precursors (26) to (37), exposure, development, printing and evaluation were carried out in the same manner as in Example 1. The results are shown in Table D.

  As is apparent from the results shown in Table D, the lithographic printing plate precursor using the specific acrylic resin of the present invention as the binder polymer for the photosensitive layer is excellent in both developability and printing durability. On the other hand, a comparative lithographic printing plate precursor using a binder polymer outside the scope of the present invention for the photosensitive layer is inferior in developability or printing durability.

Structure of automatic processor

Explanation of symbols

1: rotating brush roll 2: receiving roll 3: transport roll 4: transport guide plate 5: spray pipe 6: pipeline 7: filter 8: plate supply table 9: plate discharge table 10: developer tank 11: circulation pump 12: plate

Claims (18)

  A lithographic printing plate precursor having a photosensitive layer on a support, subjected to image exposure with a laser of 350 to 450 nm, and then subjected to an rubbing member by an automatic processor equipped with a rubbing member in the presence of a developer having a pH of 2 to 10 In the planographic printing original plate in which the photosensitive layer in the non-exposed portion is removed by rubbing the plate surface, the photosensitive layer is (A) a sensitizing dye that absorbs light of 350 to 450 nm, (B) a polymerization initiator, (C) A polymerizable compound, and (D) a photosensitive resin composition containing a binder polymer, wherein the (D) binder polymer has a hydrophilic group and a crosslinkable group and has an acid value of 0.3 meq / g or less. A lithographic printing plate precursor characterized by being an acrylic resin. A lithographic printing plate precursor having a photosensitive layer on a support, subjected to image exposure with a laser of 350 to 450 nm, and then subjected to an rubbing member by an automatic processor equipped with a rubbing member in the presence of a developer having a pH of 2 to 10 In the planographic printing original plate in which the photosensitive layer in the non-exposed portion is removed by rubbing the plate surface, the photosensitive layer is (A) a sensitizing dye that absorbs light of 350 to 450 nm, (B) a polymerization initiator, (C) a polymerizable compound, and (D) a photosensitive resin composition containing a binder polymer, wherein the (D) binder polymer has an SP value of 19.0 to 21.5 (MPa) ^1/2 , and A lithographic printing plate precursor comprising an acrylic resin having an acid value of 0.3 meq / g or less.   The lithographic printing plate precursor as claimed in claim 2, wherein the acrylic resin has a hydrophilic group and a crosslinkable group.   The lithographic printing plate precursor as claimed in claim 1 or 3, wherein the acrylic resin contains polymerized units having a hydrophilic group and a crosslinkable group.   The lithographic printing plate precursor as claimed in claim 4, wherein the crosslinkable group is an ethylenically unsaturated bond group.   The lithographic printing plate precursor as claimed in claim 5, wherein the ethylenically unsaturated bond group is an allyl group or a methacryloyl group.   The lithographic printing plate precursor as claimed in any one of claims 1 to 6, further comprising a protective layer on the photosensitive layer.   The lithographic printing plate precursor as claimed in any one of claims 1 to 7, wherein some or all of the components contained in the photosensitive layer are encapsulated in microcapsules.   The lithographic printing plate precursor as claimed in any one of claims 1 to 8, wherein the polymerization initiator (B) is a hexaarylbiimidazole compound.   The lithographic printing plate precursor as claimed in any one of claims 1 to 9, wherein the photosensitive layer further contains (E) a chain transfer agent. The lithographic printing plate precursor as claimed in claim 10, wherein the chain transfer agent (E) is a thiol compound represented by the following general formula (I).

Wherein R represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and A represents a 5-membered or 6-membered ring having a carbon atom together with an N═C—N moiety. (A) may further have a substituent.   The total content of the polymerizable compound (C) and the binder polymer (D) is 80% by mass or less based on the total components of the photosensitive layer. The lithographic printing plate precursor described in 1.   The lithographic plate according to any one of claims 1 to 12, further comprising an undercoat layer between the support and the photosensitive layer, wherein the undercoat layer contains a polymer compound having a crosslinkable group. A printing plate master.   On the support, (A) a sensitizing dye that absorbs light of 350 to 450 nm, (B) a polymerization initiator, (C) a polymerizable compound, and (D) an acid value having a hydrophilic group and a crosslinkable group. A lithographic printing plate precursor having a photosensitive layer containing a binder polymer which is an acrylic resin of 0.3 meq / g or less is image-exposed with a 350 to 450 nm laser, and then the pH is 2 by an automatic processor equipped with a rubbing member. A method for preparing a lithographic printing plate, comprising removing a photosensitive layer in an unexposed area by rubbing the plate surface with a rubbing member in the presence of 10 to 10. On the support, (A) a sensitizing dye that absorbs light of 350 to 450 nm, (B) a polymerization initiator, (C) a polymerizable compound, and (D) an SP value of 19.0 to 21.5 (MPa ) After exposing the lithographic printing plate precursor having a photosensitive layer containing a binder polymer that is ^1/2 and an acid value of an acrylic resin having an acid value of 0.3 meq / g or less with a laser of 350 to 450 nm, the rubbing member is A method for preparing a lithographic printing plate, comprising removing an unexposed photosensitive layer by rubbing the plate surface with a rubbing member in the presence of a developer having a pH of 2 to 10 with an automatic processor provided.   16. The method for preparing a lithographic printing plate according to claim 14, wherein the developer has a pH of 3 to 8.   The method for preparing a lithographic printing plate according to any one of claims 14 to 16, wherein the rubbing member is at least two rotating brush rolls.   The method for producing a lithographic printing plate according to any one of claims 14 to 17, wherein the exposed lithographic printing plate precursor is further subjected to a heat treatment between exposure and development.

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