JP2006130777A - Original lithographic printing plate and lithographic printing method using this original plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original lithographic printing plate which can facilitate image exposure by laser and also an aboard-the-machine development process, and can ensure the compatibility of high sensitivity with white light safety. <P>SOLUTION: This original lithographic printing plate has an image recording layer which contains (A) a polymerization initiator and (B) a polymerizable compound and can be removed by a printing ink and/or a damping water, formed on a support. In addition, the original plate has a sensitivity more than 100 times the sensitivity under an atmosphere of 20 vol% oxygen concentration, when it comes to the sensitivity under the atmosphere of 0.05 vol% oxygen concentration, and can record an image using a laser light with 250 to 420 nm wavelength under the atmosphere of not more than 0.05 vol% oxygen concentration. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lithographic printing plate precursor capable of image recording by laser light and on-machine development, and a lithographic printing method using the same.

  In recent years, in the field of lithographic printing, computer-to-plate technology has been developed in which lithographic printing plate precursors are directly exposed to laser on the basis of digital data such as computers without using a lithographic film. A lithographic printing plate of the type has been developed.

  However, conventional high-sensitivity lithographic printing plate precursors compatible with Ar lasers and FD-YAG lasers can remove plates from cardboard packaging, load them into platesetter cassettes, and sometimes manually insert plates into platesetters. They all had to work under a dark red light, and the workability was extremely bad. In contrast, conventional diazo type printing plates can be handled under yellow light or UV-cut white light, and workability is good. Therefore, the improvement in safelight suitability of high-sensitivity laser recording planographic printing plates is a market from the viewpoint of workability. It was a big request.

  In contrast, Patent Document 1 discloses a photopolymerizable photosensitive layer and an oxygen barrier protective layer containing a compound containing an ethylenic double bond capable of addition polymerization, a photopolymerization initiator system, and an organic polymer. A method for making a lithographic printing plate is described, in which a lithographic printing plate precursor having a surface is exposed with an inner drum type plate setter using semiconductor laser light in the ultraviolet to visible light region (360 to 450 nm). According to this plate making method, handling under a yellow light is possible.

On the other hand, in the plate making process of the conventional lithographic printing plate precursor, a step of dissolving and removing unnecessary portions of the image recording layer with a developer or the like is necessary after exposure. In recent years, such additional wet processing is performed. One of the problems is to make the processing unnecessary or simplified.
As one of the simple plate making methods that respond to this, for example, an exposed plate mounted on a printing machine using a lithographic printing plate precursor having an image recording layer that can be dissolved or dispersed in printing ink and / or fountain solution A method called on-press development has been proposed in which printing ink and / or dampening water is supplied to remove unexposed portions of the image recording layer to obtain a lithographic printing plate.

However, when an image recording method using light in the ultraviolet to visible region is used for an unprocessed printing plate that does not require development processing with such a developer, the image recording layer is not fixed, and is exposed to room light after exposure. Because it has photosensitivity, it must be completely shielded from light after the lithographic printing plate precursor is taken out of the package until development on the machine is completed, or it must be handled in a safelight environment. . In other cases, for example, if it is handled under a white light after exposure, unnecessary portions of the image recording layer are fogged and a remaining film is formed, which causes printing stains. Therefore, conventionally, it has been necessary to make the environment of a safe light up to a printing press work that does not require a safe light, and there has been a problem in printing work such as color adjustment. Therefore, there is a demand for a printing plate system that does not require development processing that can be operated under white light.
JP 2000-35673 A

  The present invention meets the above needs. That is, an object of the present invention is to provide a lithographic printing plate precursor capable of image exposure with a laser and on-press development, having both high sensitivity and white light safety, and a lithographic printing method using the same. .

The present invention is as follows.
1. A lithographic printing plate precursor comprising an image recording layer containing (A) a polymerization initiator and (B) a polymerizable compound and removable by printing ink and / or dampening water on a support, and having an oxygen concentration of 20 Laser light having a wavelength of 250 to 420 nm in an atmosphere having an oxygen concentration of 0.05 vol% or less and having a sensitivity of 100 times or more in an atmosphere having an oxygen concentration of 0.05 vol% with respect to the sensitivity in a volume% atmosphere. A lithographic printing plate precursor that can be used for image recording.

  2. 2. The lithographic printing plate precursor as described in 1 above, wherein the polymerization initiator is at least one selected from the group consisting of a sulfonium compound, an iodonium compound and an oxime ester compound.

  3. 3. The lithographic printing plate precursor as described in 1 or 2 above, wherein the image recording layer further contains at least one sensitizer selected from an oxadiazole compound and a coumarin compound.

  4). 4. The lithographic printing plate precursor as described in any one of 1 to 3 above, wherein the image recording layer further contains a compound having a carboxylic acid group.

  5. 5. The lithographic printing plate precursor as described in any one of 1 to 4 above, wherein the addition amount of the polymerization initiator is in the range of 1 to 10% by mass with respect to the total mass of the image recording layer.

6). The lithographic printing plate as described in any one of 1 to 5 above, which has no protective layer on the image recording layer or has a protective layer having a coating weight of 0.3 g / m ² or less. Original edition.

  7. A lithographic printing plate precursor as described in any one of 1 to 6 above, wherein the lithographic printing plate precursor is exposed in an atmosphere having an oxygen concentration of 0.05% by volume or less.

  8). An image recording layer containing (A) a polymerization initiator and (B) a polymerizable compound is provided on the support, and the oxygen concentration is 0.05 vol% with respect to the sensitivity in an atmosphere having an oxygen concentration of 20 vol%. A lithographic printing plate precursor having a sensitivity of 100 times or more in an atmosphere is exposed imagewise in an atmosphere having an oxygen concentration of 0.05% by volume or less using a light source having a wavelength of 250 to 420 nm, and then a development processing step is performed. A lithographic printing method characterized by supplying printing ink and fountain solution without printing.

The present invention has been made as a result of earnest research based on the following concept.
The white light safety of lithographic printing plate precursors using photopolymerization by UV exposure is that the polymerization reaction is suppressed if the image recording layer is exposed to the atmosphere except during exposure and oxygen diffuses quickly into the image recording layer. Therefore, it can be secured easily. On the other hand, the sensitivity of image recording can be sufficiently obtained if image exposure is performed in an oxygen-blocked state. To achieve both sensitivity and white light safety with this concept, the sensitivity difference between the presence and absence of oxygen interruption is large, that is, the oxygen concentration is 0.05 vol% with respect to the sensitivity in an atmosphere having an oxygen concentration of 20 vol%. In the case of a specific initiator species or a specific sensitizer species, the present inventor has a large sensitivity difference with or without oxygen blocking, And found that it can be compatible with.

  ADVANTAGE OF THE INVENTION According to this invention, the image exposure by a laser and on-machine image development are possible, and the lithographic printing plate precursor which can make high sensitivity and white lamp safety compatible can be provided.

  Hereinafter, the elements and components constituting the lithographic printing plate precursor according to the invention will be described in detail.

(Image recording layer)
The image recording layer of the present invention contains (A) a polymerization initiator and (B) a polymerizable compound, and can be removed by printing ink and / or fountain solution. In addition, the image recording layer of the present invention has a sensitivity of 100 times or more in an atmosphere with an oxygen concentration of 0.05 vol%, and an oxygen concentration of 0.05 vol with respect to the sensitivity in an atmosphere with an oxygen concentration of 20 vol%. %, A lithographic printing plate precursor capable of recording an image with a laser beam having a wavelength of 250 to 420 nm is obtained.

<(A) Polymerization initiator>
The polymerization initiator used in the present invention is a compound that generates radicals by light energy and initiates and accelerates the polymerization of a compound having a polymerizable unsaturated group. In particular, the polymerization initiator alone or the polymerization initiator and It is a compound that generates radicals by absorbing light of 250 nm to 420 nm in combination with a sensitizer. As such a photo radical generator, a known polymerization initiator, a compound having a bond having a small bond dissociation energy, or the like can be appropriately selected and used.
The emission spectrum intensity of white light is strong in the visible region exceeding 400 nm, and a polymerization initiator having sufficient photosensitivity in that region is likely to cause fogging under white light. Therefore, absorption of the initiator and the sensitizer is difficult. The maximum is preferably 400 nm or less.

  Examples of the polymerization initiator having a sensitivity of 100 times or more in an atmosphere having an oxygen concentration of 0.05% by volume with respect to the sensitivity in an atmosphere having an oxygen concentration of 20% by volume include, for example, carbonyl compounds, organic peroxides, and azo series. Examples thereof include compounds, azide compounds, hexaarylbiimidazole compounds, organic boron compounds, disulfone compounds, oxime ester compounds, and onium salt compounds.

  Examples of the carbonyl compound include benzophenone, Michler ketone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2-chlorobenzophenone, 4-bromobenzophenone, 2-carboxybenzophenone and other benzophenone derivatives, 2,2-dimethoxy- 2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, α-hydroxy-2-methylphenylpropanone, 1-hydroxy-1-methylethyl- (p-isopropylphenyl) ketone, 1- Hydroxy-1- (p-dodecylphenyl) ketone, 2-methyl- (4 ′-(methylthio) phenyl) -2-morpholino-1-propanone, 1,1,1-trichloromethyl- (p-butylphenyl) Acetophenone derivatives such as ketones, thioxanthone derivatives such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, p- Examples thereof include benzoic acid ester derivatives such as ethyl dimethylaminobenzoate and ethyl p-diethylaminobenzoate.

  As the azo compound, for example, an azo compound described in JP-A-8-108621 can be used.

  Examples of the organic peroxide include trimethylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-butyl). Peroxy) cyclohexane, 2,2-bis (tert-butylperoxy) butane, tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydro Peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, tert-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2, -Oxanoyl peroxide, succinic peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate , Dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, tert-butyl peroxyacetate, tert-butyl peroxypivalate, tert-butyl peroxyneodecanoate, tert- Butyl peroxyoctanoate, tert-butyl peroxylaurate, tersyl carbonate, 3,3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4 ′ − Tra- (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogen diphthalate), carbonyl And di (t-hexylperoxydihydrogen diphthalate).

Examples of the hexaarylbiimidazole compound include the specifications of JP-B-6-29285, US Pat. Nos. 3,479,185, 4,311,783, and 4,622,286. And, specifically, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-bromophenyl) )) 4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (
o, p-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (m-methoxyphenyl) ) Bididazole, 2,2′-bis (o, o′-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-nitrophenyl) -4,4 ′ , 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4 '
, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, and the like.

  Examples of the organoboron compound include JP-A-62-143044, JP-A-62-1050242, JP-A-9-188585, JP-A-9-188686, JP-A-9-188710, JP-A 2000-. No. 131837, Japanese Patent Application Laid-Open No. 2002-107916, Japanese Patent No. 2764769, Japanese Patent Application Laid-Open No. 2002-116539, and Kunz, Martin “Rad Tech '98. Proceeding April 19-22, 1998, Chicago”, etc. The organic borate described in JP-A-6-157623, JP-A-6-175564, JP-A-6-175561, or organic boron oxosulfonium complex, JP-A-6-175554 No. 6, JP-A-6-17555 Organoboron iodonium complex described in JP-A-9-188, organoboron phosphonium complex described in JP-A-9-188710, JP-A-6-34811, JP-A-7-128785, JP-A-7-140589, Examples thereof include organoboron transition metal coordination complexes such as Kaihei 7-306527 and JP-A-7-292014.

  Examples of the disulfone compound include compounds described in JP-A Nos. 61-166544 and 2003-328465.

  Examples of the oxime ester compound include JCS Perkin II (1979) 1653-1660), JCSPerkin II (1979) 156-162, Journal of Photopolymer Science and Technology (1995) 202-232, and JP-A 2000-66385. Compounds, compounds described in JP-A No. 2000-80068, specifically, compounds represented by the following structural formulas may be mentioned.

  Examples of the onium salt compound include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Diazonium salts described in Bal et al, Polymer, 21, 423 (1980), ammonium salts described in US Pat. No. 4,069,055, JP-A-4-365049, etc., US Pat. No. 4,069 , 055, 4,069,056, phosphonium salts described in European Patent Nos. 104,143, US Pat. Nos. 339,049, 410,201, JP -150848, JP-A-2-296514, iodonium salts, European Patent Nos. 370,693, 390,214, 233,567, 297,443, and 297 442, U.S. Pat. Nos. 4,933,377, 161,811, 410,201, 339,049, 4,760,013 No. 4,734,444, No. 2,833,827, German Patent No. 2,904,626, No. 3,604,580, No. 3,604,581 Or a sulfonium salt described in J. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), and onium salts such as arsonium salts.

In the present invention, these onium salts function not as acid generators but as ionic radical polymerization initiators.
The onium salts suitably used in the present invention are onium salts represented by the following general formulas (RI-I) to (RI-III).

In the formula (RI-I), Ar ₁₁ represents an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include an alkyl group having 1 to 12 carbon atoms and a carbon number. 1-12 alkenyl group, C1-C12 alkynyl group, C1-C12 aryl group, C1-C12 alkoxy group, C1-C12 aryloxy group, halogen atom, C1-C1 12 alkylamino groups, C1-C12 dialkylamino groups, C1-C12 alkylamide groups or arylamide groups, carbonyl groups, carboxyl groups, cyano groups, sulfonyl groups, C1-C12 thioalkyl groups And a thioaryl group having 1 to 12 carbon atoms. Z ₁₁ ^- represents a monovalent anion, specifically a halogen ion, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, thiosulfonate ion, a sulfate ion Can be mentioned. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion and sulfinate ion are preferable from the viewpoint of stability.

In the formula (RI-II), Ar ₂₁ and Ar ₂₂ each independently represent an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include 1 to 1 carbon atoms. 12 alkyl groups, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 1 to 12 carbon atoms, Halogen atom, C1-C12 alkylamino group, C1-C12 dialkylamino group, C1-C12 alkylamide group or arylamide group, carbonyl group, carboxyl group, cyano group, sulfonyl group, carbon Examples thereof include a thioalkyl group having 1 to 12 carbon atoms and a thioaryl group having 1 to 12 carbon atoms. Z ₂₁ ^- represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable from the viewpoint of stability and reactivity.

In the formula (RI-III), R ₃₁ , R ₃₂ and R ₃₃ are each independently an aryl group, alkyl group, alkenyl group or alkynyl having 20 or less carbon atoms, which may have 1 to 6 substituents. Represents a group. Among them, an aryl group is preferable from the viewpoint of reactivity and stability. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, Aryloxy group having 1 to 12 carbon atoms, halogen atom, alkylamino group having 1 to 12 carbon atoms, dialkylamino group having 1 to 12 carbon atoms, alkylamide group or arylamide group having 1 to 12 carbon atoms, carbonyl group, carboxyl Group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms. Z ₃₁ ^- represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable from the viewpoints of stability and reactivity. More preferred are the carboxylate ions described in JP-A No. 2001-343742, and particularly preferred are the carboxylate ions described in JP-A No. 2002-148790.

  As the polymerization initiator, the above-mentioned polymerization initiators are useful, but oxime ester compounds, iodonium salts, and sulfonium salts are more preferable from the viewpoints of reactivity and stability.

  These oxime ester, iodonium, and sulfonium-based polymerization initiators are preferably used in combination with a sensitizer (also called a spectral sensitizer). By using in combination with a sensitizer, the photopolymerization rate can be increased, and the sensitivity in an atmosphere with an oxygen concentration of 0.05 vol% is higher than the sensitivity in an atmosphere with an oxygen concentration of 20 vol%. Become.

  When a sensitizer is combined with the initiator system of the present invention, a sensitizer that increases the photopolymerization rate when used in combination with the photopolymerization initiator is selected. Specific examples of such a sensitizer include benzoin, benzoin methyl ether, benzoin ethyl ether, 9-fluorenone, 2-chloro-9-fluorenone, 9-anthrone, 2-bromo-9-anthrone, and 2-ethyl-9. Anthrone, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, 2-t-butyl-9,10-anthraquinone, 2,6-dichloro-9,10-anthraquinone, xanthone, 2-methylxanthone, 2-methoxyxanthone, thioxanthone, benzyl, dibenzylacetone, p- (dimethylamino) phenyl styryl ketone, p- (dimethylamino) phenyl p-methylstyryl ketone, benzophenone, p- (dimethylamino) benzophenone (or Michler's ketone), p- (Diethyla Roh) benzophenone, such as benzanthrone can be mentioned.

  Furthermore, preferred sensitizers in the present invention include compounds represented by the general formula (1) described in JP-B-51-48516.

In the formula, R ₁ is an alkyl group (for example, methyl group, ethyl group, propyl group, etc.) or a substituted alkyl group (for example, 2-hydroxyethyl group, 2-methoxyethyl group, carboxymethyl group, 2-carboxyethyl group) Etc.). R ₂ represents an alkyl group (eg, methyl group, ethyl group, etc.) or an aryl group (eg, phenyl group, p-hydroxyphenyl group, naphthyl group, thienyl group, etc.).
Z ¹ is a group of non-metallic atoms necessary for forming a nitrogen-containing heterocyclic nucleus usually used in cyanine dyes, such as benzothiazoles (benzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, etc.), naphtho Thiazoles (α-naphthothiazole, β-naphthothiazole, etc.), benzoselenazoles (benzoselenazole, 5-chlorobenzoselenazole, 6-methoxybenzoselenazole, etc.), naphthoselenazoles (α-naphthoselenazole) , Β-naphthselenazole, etc.), benzoxazoles (benzoxazole, 5-methylbenzoxazole, 5-phenylbenzoxazole, etc.) and naphthoxazoles (α-naphthoxazole, β-naphthoxazole, etc.).

Specific examples of the compound represented by the general formula (1) are those having a chemical structure combining these Z ¹ , R ¹ and R ² , and many exist as known substances. Therefore, it can be used by appropriately selecting from these known ones. Furthermore, preferred sensitizers in the present invention also include merocyanine dyes described in JP-B-5-47095 and JP-A-2000-147663.

  Furthermore, as a preferable sensitizer in this invention, the oxadiazole compound shown by following General formula (2) is mentioned.

In the formula, R ₃ and R ₄ are each an alkyl group (for example, methyl group, ethyl group, propyl group, etc.), a substituted alkyl group (for example, 2-hydroxyethyl group, 2-methoxyethyl group, carboxymethyl group, 2 -Carboxyethyl group, etc.) or an aryl group (for example, phenyl group, p-hydroxyphenyl group, naphthyl group, p-aminophenyl group, biphenyl group, etc.).

  Moreover, as a preferable sensitizer in this invention, the coumarin compound shown by following General formula (3) is also mentioned.

(In the formula, Y represents a carbonyl group, a thiocarbonyl group, an imino group or an alkylidene group represented by the partial structural formula (1), and X ₁ and X ₂ are each independently a monovalent nonmetallic atom. And X ₁ and X ₂ may combine with each other to form an acidic nucleus of the dye. R ₅ to R ₁₀ each independently represents a monovalent nonmetallic atomic group.)

Preferred examples of the monovalent nonmetallic atomic group represented by X ₁ to X ₂ and R ₅ to R ₁₀ in the general formula (3) include a hydrogen atom, an alkyl group (for example, a methyl group, an ethyl group, a propyl group). 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, 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, methoxycarbonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl Group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- Sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N- Methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphono Hexyl 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-propeni Rumethyl 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 group, phenoxycarbonylphenyl group, N Phenylcarbamoylphenyl group, phenyl 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, sinoline, pteridine , Carbazole, carboline, phenanthrine, acridine, perimidine, phenanthroline, phthalazine, phenazazine, phenoxazine, furazane, phenoxadi Etc.), alkenyl groups (for example, vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group, 2-chloro-1-ethenyl group, etc.), alkynyl groups (for example, ethynyl group, 1-propynyl group, 1- Butynyl group, trimethylsilylethynyl group, etc.), halogen atom (-F, -Br, -Cl, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group , Amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N -Alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarba Moyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacyl Amino 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 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, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group N-alkylcarbamoyl group, N, N-dialkylcal Moil group, N- arylcarbamoyl group, N, N- di arylcarbamoyl group, N- alkyl -N- arylcarbamoyl group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H ) And its conjugate base group (hereinafter referred to as sulfonate group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfina Moyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfuric group Famoyl group, N, N-diaryls Rufamoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonato group), dialkylphosphono group (—PO ₃ (alkyl) ₂ ), Diarylphosphono group (—PO ₃ (aryl) ₂ ), alkylaryl phosphono group (—PO ₃ (alkyl) (aryl)), monoalkylphosphono group (—PO ₃ H (alkyl)) and conjugation thereof A base group (hereinafter referred to as an alkylphosphonate group), a monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as an arylphosphonate group), a phosphonooxy group (—OPO ₃ H) ₂ ) and its conjugate base group (hereinafter referred to as phosphonatoxy group), dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphono An oxy group (—OPO ₃ (alkyl) (aryl)), a monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as an alkylphosphonatoxy group), a monoarylphosphono Examples thereof include an oxy group (—OPO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as arylphosphonatooxy group), a cyano group, a nitro group, etc. Among these substituents, a hydrogen atom, an alkyl Particularly preferred are groups, aryl groups, halogen atoms, alkoxy groups and acyl groups.

  Specific examples of the oxadiazole compound and the coumarin compound are given below, but the sensitizer that can be used in the present invention is not limited thereto.

  As the sensitizer, merocyanine dyes described in JP-A No. 2000-147763 can also be used. Specifically, the following compounds can be mentioned.

  These polymerization initiators and sensitizers are each preferably added in an amount of 1 to 10 mass%, more preferably 1 to 5 mass%, based on the total solid content constituting the image recording layer. Within this range, both sensitivity and safety can be achieved. These polymerization initiators may be used alone or in combination of two or more. Moreover, these polymerization initiators may be added to the same layer as other components, or another layer may be provided and added thereto.

<(B) Polymerizable compound>
The polymerizable compound that can be used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is selected from compounds having at least one ethylenically unsaturated bond, preferably two or more. It is. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), and esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and a monofunctional or polyfunctional compound. A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or Also suitable are substitution reaction products of unsaturated carboxylic acid esters or amides having a leaving substituent such as a tosyloxy group with monofunctional or polyfunctional alcohols, amines or thiols. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

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

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

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

  Examples of other esters include, for example, aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, and JP-A-59-5241. Those having an aromatic skeleton described in 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-54-21726.

In addition, urethane-based addition-polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. 1 to which a vinyl monomer containing a hydroxyl group represented by the following general formula (4) was added to a polyisocyanate compound having two or more isocyanate groups.
Examples thereof include vinyl urethane compounds containing two or more polymerizable vinyl groups in the molecule.

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

  Further, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56-17654 Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable. Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238. Can obtain a photopolymerizable composition having an excellent photosensitive speed.

  Other examples include reacting polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490. And polyfunctional acrylates and methacrylates such as epoxy acrylates. Further, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, and JP-B-1-40336, vinylphosphonic acid compounds described in JP-A-2-25493, and the like are 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 selection and use method of the polymerized compound is also an important factor for the compatibility and dispersibility with other components in the image recording layer (for example, binder polymer, initiator, colorant, etc.). The compatibility may be improved by using a low-purity compound or using two or more kinds in combination. In addition, a specific structure may be selected for the purpose of improving the adhesion of the substrate and the protective layer described later.

  The polymerizable compound is preferably used in the range of 5 to 80% by mass, more preferably 25 to 75% by mass with respect to the total solid content constituting the image recording layer. These may be used alone or in combination of two or more. In addition, the use method of the addition polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface adhesiveness, etc. Depending on the case, a layer configuration and coating method such as undercoating and overcoating can be performed.

<Compound having a carboxylic acid group>
The image recording layer of the present invention preferably contains a compound having a carboxylic acid group in order to accelerate polymerization and improve on-press developability.
The compound having a carboxylic acid group used in the present invention is not limited and any conventionally known compound may be used. Further, carboxylic acid compounds and polycarboxylic acid compounds described in International Publication No. 00/048836 and International Publication No. 97/12759 are also preferred.
Moreover, the monocarboxylic acid compound represented by following General formula (5) is mentioned as one of the preferable aspects.

In general formula (5), A represents an aromatic group or a heterocyclic group. R ¹ and R ² each independently represents a hydrogen atom or a monovalent substituent. R ¹ and R ² , R ¹ and R ² and X, R ¹ and R ² and A, A and X may be bonded to each other to form a ring structure. X is —O—, —S—, —SO ₂ —, —NH—, —N (R ³ ) —, —CH ₂ —, —CH (R ⁴ ) — and —C (R ⁴ ) (R ⁵ )-Represents a divalent linking group selected from R, R ³ , R ⁴ or R ⁵ each independently represents a hydrogen atom or a monovalent substituent.

Here, in the general formula (5), the aromatic group represented by A includes a benzene ring, two to three benzene rings forming a condensed ring, and a benzene ring and a 5-membered unsaturated ring condensed. Examples thereof include those having a ring formed. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable.
The aromatic group may have a substituent, and examples of the aromatic group having such a substituent include a substituted aryl group described later. In addition, as an example of the preferable substituent introduce | transduced here, what was shown as a substituent in the below-mentioned alkyl group, substituted alkyl group, and substituted alkyl group can be mentioned.

As the heterocyclic group represented by A, a pyrrole ring group, a furan ring group, a thiophene ring group, a benzopyrrole ring group, a benzofuran ring group, a benzothiophene ring group, a pyrazole ring group, an isoxazole ring group, an isothiazole ring group, Indazole ring group, benzisoxazole ring group, benzoisothiazole ring group, imidazole ring group, oxazole ring group, thiazole ring group, benzimidazole ring group, benzoxazole ring group, benzothiazole ring group, pyridine ring group, quinoline ring Group, isoquinoline ring group, pyridazine ring group, pyrimidine ring group, pyrazine ring group, phthalazine ring group, quinazoline ring group, quinoxaline ring group, acylidene ring group, phenanthridine ring group, carbazole ring group, purine ring group, pyran ring Group, piperidine ring group, piperazine ring group, morpholine ring group, indole ring group, Ndorijin ring group, a chromene ring group, a cinnoline ring group, an acridine ring group, a phenothiazine ring group, a tetrazole ring group, a triazine ring group, and the like.
Further, the heterocyclic group may have a substituent, and examples of such a substituent include a substituent of a substituted aryl group described later. Examples of preferred substituents include the alkyl groups, substituted alkyl groups described below, and those shown as substituents in the substituted alkyl group.

Next, as the monovalent substituent represented by R ¹ and R ² in the general formula (5), a halogen atom, an amino group which may have a substituent, an alkoxycarbonyl group, a hydroxyl group, an ether group, Examples include a thiol group, a thioether group, a silyl group, a nitro group, and a cyano group, and an alkyl group, an alkenyl group, an alkynyl group, an aryl group, and a heterocyclic group, each of which may have a substituent.

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

As the substituent that such an alkyl group may have, a group consisting of a monovalent non-metallic atomic group excluding a hydrogen atom is used, and preferable examples include halogen atoms (—F, —Br, —Cl, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-aryl Amino 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-arylcarba Ileoxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkyl Ureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N -Alkylureido group, N'-alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N -Alkylureido group, N'-aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl -N-arylureido group, N'-alkyl-N'-aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl Group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N -Arylcarbamoyl group, alkyl Rusulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group (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-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 (a phosphonato group Be), dialkylphosphono group (-PO ₃ (alkyl) ₂₎ "alkyl = alkyl group, hereinafter the" diarylphosphono group (-PO ₃ (aryl) ₂₎ "aryl = aryl group, hereinafter the" alkyl An arylphosphono group (—PO ₃ (alkyl) (aryl)), a monoalkylphosphono group (—PO ₃ (alkyl)) and its conjugate base group (referred to as an alkylphosphonato group), a monoarylphosphono group (— PO ₃ H (aryl)) and its conjugate base group (referred to as arylphosphonate group), phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (referred to as phosphonatoxy group), dialkylphosphonooxy group (—OPO) ₃ H (alkyl) _2), diaryl phosphono group _{(-OPO 3 (aryl) 2)} , alkyl aryl phosphites flames key Group (-OPO ₃ (alkyl) (aryl)), (referred to as alkylphosphonato group) monoalkyl phosphono group (-OPO ₃ H (alkyl)) and its conjugated base group, monoarylphosphono group ( -OPO ₃ H (aryl)) and its conjugated base group (hereinafter referred to as aryl phosphite Hona preparative group), a cyano group, a nitro group, an aryl group, an alkenyl group, an alkynyl group, a heterocyclic group, a silyl group, and the like.

  Specific examples of the alkyl group in these substituents include the above-described alkyl groups, and specific examples of the aryl group in the substituent include 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 group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl , It can be exemplified cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, a phosphate Hona preparative phenyl group.

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.
The R ⁰¹ of the acyl group (R ⁰¹ CO-), include hydrogen atom, and the above-described alkyl group, an aryl group. Among these substituents, halogen atoms (—F, —Br, —Cl, —I), alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, N-alkylamino groups, N, N are more preferable. -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 Group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonate group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfa group Moyl group, N-arylsulfur Amoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group, phosphonato group, dialkylphosphono group, diarylphosphono group, monoalkylphosphono group, alkylphosphonato group, monoarylphosphono group, arylphospho Examples thereof include a nato group, a phosphonooxy group, a phosphonatooxy group, an aryl group, and an alkenyl group.
Examples of the heterocyclic group include a pyridyl group and a piperidinyl group. Examples of the silyl group include a trimethylsilyl group.

  On the other hand, examples of the alkylene group in the substituted alkyl group include divalent organic residues 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. Preferable specific examples of the substituted alkyl group obtained by combining such a substituent and an alkylene group include a chloromethyl group, a bromomethyl group, a 2-chloroethyl group, a trifluoromethyl group, a methoxymethyl group, and an isopropoxymethyl group. , Butoxymethyl group, s-butoxybutyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, pyridylmethyl group, tetramethylpiperidinylmethyl group, N-acetyltetra Methylpiperidinylmethyl group, trimethylsilylmethyl group, methoxyethyl 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, 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- (phosphonov Nyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl 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- Examples thereof include a propenylmethyl group, a 2-butenyl group, a 2-methylallyl group, a 2-methylpropenylmethyl group, a 2-propynyl group, a 2-butynyl group, and a 3-butynyl group.

Examples of the aryl group include a benzene ring, a ring in which 2 to 3 benzene rings form a condensed ring, and a group in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. Specific examples include: Examples thereof include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable.
As the substituted aryl group, those having a group consisting of a monovalent non-metallic atomic group other than a hydrogen atom as a substituent on the ring-forming carbon atom of the aforementioned aryl group are used. 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, cal Xiphenyl 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, diphenylphosphonophenyl Methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonophenyl group, allylphenyl group, 1-propenylmethylphenyl group, 2-butenylphenyl group, 2-methylallylphenyl group, A 2-methylpropenylphenyl group, a 2-propynylphenyl group, a 2-butynylphenyl group, a 3-butynylphenyl group, and the like can be given.

An alkenyl group, a substituted alkenyl group, an alkynyl group, and a substituted alkynyl group (—C (R ⁰² ) ═C (R ⁰³ ) (R ⁰⁴ ) and —C≡C (R ⁰⁵ )) include R ⁰² , R ⁰³ , R ⁰⁴ , and R ⁰⁵ can be a group composed of a monovalent nonmetallic atomic group. Preferable examples of R ⁰² , R ⁰³ , R ⁰⁴ and R ⁰⁵ include a hydrogen atom, a halogen atom, an alkyl group, a substituted alkyl group, an aryl group and a substituted aryl group. Specific examples thereof include those shown as the above examples. More preferable groups of R ⁰² , R ⁰³ , R ⁰⁴ , and R ⁰ include a hydrogen atom, a halogen atom, and a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms.

Preferable specific examples of such alkenyl group, substituted alkenyl group, alkynyl group and substituted alkynyl group include vinyl group, 1-propenyl group, 1-butenyl group, 1-pentenyl group, 1-hexenyl group and 1-octenyl group. 1-methyl-1-propenyl group, 2-methyl-1-propenyl group, 2-methyl-1-butenyl group, 2-phenyl-1-ethenyl group, 2-chloro-1-ethenyl group, ethynyl group, 1 -A propynyl group, 1-butynyl group, and phenylethynyl group can be mentioned.
Examples of the heterocyclic group include the pyridyl group exemplified as the substituent of the substituted alkyl group.

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

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

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

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

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

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

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

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

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

Next, X in the general formula (5) will be described. X is —O—, —S—, —SO ₂ —, —NH—, —N (R ³ ) —, —CH ₂ —, —CH (R ⁴ ) — and —C (R ⁴ ) (R ⁵ ) - represents a divalent linking group selected from, among others, -NH -, - N (R 3) -, - CH 2 -, - CH (R 4) -, - C (R 4) (R 5 ) - preferably from the viewpoint of sensitivity, -NH -, - N (R 3) - , more preferably, -N (R ³⁾ - is most preferable in terms of sensitivity and storage stability is.

Here, R ³ , R ⁴ and R ⁵ in X each independently represent a hydrogen atom or a monovalent substituent. Examples of such a monovalent substituent include R ¹ in the general formula (5). , R ² is synonymous.
In particular, R ³ is preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, each of which may have a substituent. R ³ preferably has at least one of —CO ₂ — and —CON (R ⁸ ) — in its structure, and the most preferable structure of R ³ is represented by the following formula. Is.

In the above formula, R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or a monovalent substituent, and Z represents a monovalent substituent. Such a monovalent substituent has the same meaning as R ¹ or R ² in the general formula (5).

Further, the monovalent substituent represented by R ⁴ and R ⁵ in X is the same as R ¹ or R ² in the general formula (5).

  Hereinafter, although the specific example (A-1)-(A-87) of the monocarboxylic acid compound represented by General formula (5) is given, this invention is not limited to these.

  The compound having a carboxylic acid group according to the present invention described above may be used alone or in combination of two or more. The amount of the compound having a carboxylic acid group added is 0.1 to 70% by mass, preferably 0.5 to 50% by mass, more preferably 1 to 30% by mass in the total solid content constituting the image recording layer. % Can be added. When the addition amount is 0.1% by mass or more, the effect of improving the sensitivity is sufficient, and when the addition amount is 70% by mass or less, the on-press developability is improved, and the film properties of the image recording layer before and after curing are also improved. It becomes good.

<Binder polymer>
In the present invention, a binder polymer can be used for improving the film strength and film property of the image recording layer and improving the on-press developability. A conventionally well-known thing can be used as a binder polymer without a restriction | limiting, The linear organic polymer which has film property is preferable. Examples of such binder polymers include acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, methacrylic resins, polystyrene resins, novolac phenolic resins, polyester resins, and synthetic rubbers. And natural rubber.
The binder polymer preferably has crosslinkability in order to improve the film strength of the image area. In order to impart crosslinkability to the binder polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may be introduced by copolymerization.
Examples of the polymer having an ethylenically unsaturated bond in the main chain of the molecule include poly-1,4-butadiene and poly-1,4-isoprene.
Examples of polymers having an ethylenically unsaturated bond in the side chain of the molecule are polymers of esters or amides of acrylic acid or methacrylic acid where the ester or amide residue (R of -COOR or -CONHR) is Mention may be made of polymers having an ethylenically unsaturated bond.

Examples of the residue (the R) having an ethylenically unsaturated _{bond, - (CH 2) n CR} 1 = CR 2 R 3, - (CH 2 O) n CH 2 CR 1 = CR 2 R 3, - _{(CH 2 CH 2 O) n} CH 2 CR 1 = CR 2 R 3, - (CH 2) n NH-CO-O-CH 2 CR 1 = CR 2 R 3, - (CH 2) n -O-CO —CR ¹ ═CR ² R ³ and — (CH ₂ CH ₂ O) ₂ —X (wherein R ^{1 to} R ³ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, Represents an alkoxy group or an aryloxy group, and R ¹ and R ² or R ³ may combine with each other to form a ring, n represents an integer of 1 to 10. X represents dicyclopentadienyl. Represents a residue).
Specific examples of the ester _{residue, -CH 2 CH = CH 2,} ( described in JP Kokoku _{7-21633.) - CH 2 CH 2} O-CH 2 CH = CH 2, -CH 2 C _{(CH 3) = CH 2,} -CH 2 CH = CH-C 6 H 5, -CH 2 CH 2 OCOCH = CH-C 6 H 5, -CH 2 CH 2 -NHCOO-CH 2 CH = CH 2 and - CH ₂ CH ₂ O—X (wherein X represents a dicyclopentadienyl residue).
Specific examples of the amide residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ —Y (wherein Y represents a cyclohexene residue), —CH ₂ CH ₂ —OCO—CH═CH _2. Is mentioned.

  In the case of a binder polymer having crosslinkability, 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 a polymerization chain of a polymerizable compound is formed directly between polymers. Through addition polymerization, a cross-link is formed between the polymer molecules and cured. Alternatively, atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to the functional bridging group) are abstracted by free radicals to form polymer radicals that are bonded to each other so that crosslinking between the polymer molecules occurs. Forms and cures.

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

Further, from the viewpoint of on-press developability of the image recording layer unexposed portion, the binder polymer preferably has high solubility or dispersibility in ink and / or fountain solution.
In order to improve the solubility or dispersibility in ink, the binder polymer is preferably lipophilic, and in order to improve the solubility or dispersibility in dampening water, the binder polymer is hydrophilic. Is preferred. For this reason, in the present invention, it is also effective to use a lipophilic binder polymer and a hydrophilic binder polymer in combination.

  Examples of hydrophilic binder polymers include hydroxy groups, carboxyl groups, carboxylate groups, hydroxyethyl groups, polyoxyethyl groups, hydroxypropyl groups, polyoxypropyl groups, amino groups, aminoethyl groups, aminopropyl groups, and ammonium. Preferred are those having a hydrophilic group such as a group, an amide group, a carboxymethyl group, a sulfonic acid group, and a 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 binder polymer 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. More preferred. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The binder polymer may be any of a random polymer, a block polymer, a graft polymer, and the like, but is preferably a random polymer.

The binder polymer can be synthesized by a conventionally known method. Solvents used in the synthesis include, for example, tetrahydrofuran, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, diethylene glycol dimethyl ether, 1-methoxy. Examples include 2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, toluene, ethyl acetate, methyl lactate, ethyl lactate, dimethyl sulfoxide, and water. These may be used alone or in combination of two or more.
As the radical polymerization initiator used for synthesizing the binder polymer, known compounds such as an azo initiator and a peroxide initiator can be used.

A binder polymer may be used independently or may be used in mixture of 2 or more types.
The content of the binder polymer is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and still more preferably 30 to 70% by mass with respect to the total solid content of the image recording layer. Within this range, good image area strength and image formability can be obtained.
Moreover, it is preferable to use (B) polymeric compound and binder polymer in the quantity used as 1 / 9-7 / 3 by mass ratio.

<Other image recording layer components>
In the image recording layer of the present invention, additives such as a surfactant, a colorant, a print-out agent, a polymerization inhibitor, a higher fatty acid derivative, a plasticizer, inorganic fine particles, and a low molecular weight hydrophilic compound are added as necessary. Can be contained. These will be described below.

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

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

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

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

Surfactant can be used individually or in combination of 2 or more types.
The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 7% by mass with respect to the total solid content of the image recording layer.

<Colorant>
In the present invention, various compounds other than these may be added as necessary. For example, 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) Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc., and JP-A-62-2 And dyes described in Japanese Patent No. 293247. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, titanium oxide, etc. can be suitably used.

  These colorants are preferably added since it is easy to distinguish an image area from a non-image area after image formation. The amount added is preferably 0.01 to 10% by mass with respect to the total solid content of the image recording material.

<Bakeout agent>
In the image recording layer of the present invention, a compound that changes color by an acid or a radical can be added to produce 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, Parafuchsin, 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 image recording layer.

<Polymerization inhibitor>
In order to prevent unnecessary thermal polymerization of the (C) radical polymerizable compound during production or storage of the image recording layer, it is preferable to add a small amount of a thermal polymerization inhibitor to the image recording 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 image recording layer.

<Higher fatty acid derivatives, etc.>
A higher fatty acid derivative such as behenic acid or behenic acid amide or the like may be added to the image recording layer of the present invention so that it is unevenly distributed on the surface of the image recording layer in the course of drying after coating. The amount of the higher fatty acid derivative added is preferably about 0.1 to about 10% by mass with respect to the total solid content of the image recording layer.

<Plasticizer>
The image recording layer of the present invention may contain a plasticizer in order to improve the on-press developability.
Examples of the plasticizer include 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 image recording layer.

<Inorganic fine particles>
The image recording layer of the present invention may contain inorganic fine particles for the purpose of improving the strength of the cured film in the image area and improving the on-press developability of the non-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 image recording layer, sufficiently retains the film strength of the image recording layer, and hardly causes stains during printing. .
The inorganic fine particles as described above can be easily obtained as a commercial product such as a colloidal silica dispersion.
The content of the inorganic fine particles is preferably 20% by mass or less, and more preferably 10% by mass or less, based on the total solid content of the image recording layer.

<Low molecular hydrophilic compound>
The image recording layer of the present invention may contain a hydrophilic low molecular weight compound for improving on-press developability. Examples of hydrophilic low molecular weight compounds include water-soluble organic compounds such as glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol, and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, ammonium salts such as tetraethylammonium chloride, organic sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid and salts thereof, phenyl Organic phosphonic acids such as phosphonic acid and salts thereof, organic carboxylic acids such as tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid and amino acids, and The salt and the like.

<Formation of image recording layer>
In the present invention, several modes can be used as a method for incorporating the above-mentioned image recording layer constituents into the image recording layer. One is a molecular dispersion type image recording layer in which the constituent components are dissolved and applied in an appropriate solvent as described in, for example, JP-A-2002-287334. Another aspect is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2001-277740 and 2001.
As described in JP-A-277742, a microcapsule type image recording layer in which all or part of the constituent components are encapsulated in a microcapsule and contained in the image recording layer. Further, in the microcapsule type image recording layer, the constituent component can be contained outside the microcapsule. Here, it is preferable that the microcapsule-type image recording layer includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule. In order to obtain better on-press developability, the image recording layer is preferably a microcapsule type image recording layer.

  As a method of microencapsulating the above-mentioned image recording layer constituent components, known methods can be applied. For example, as a method for producing microcapsules, a method using coacervation as described in the specifications of U.S. Pat. Nos. 2,800,047 and 2,800,498, U.S. Pat. No. 3,287,154, JP-B-38-19574, and 42. -46 method by interfacial polymerization, US Pat. No. 3,418,250, US Pat. No. 3,660,304, by polymer precipitation method, US Pat. No. 3,796,669, isocyanate polyol wall A method using a material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, a urea-formaldehyde system or a urea found in US Pat. Nos. 4001140, 4087376, and 4089802 Formaldehyde-resorcinol system A method using a 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 a monomer polymerization as shown in Japanese Patent Publication Nos. 36-9163 and 51-9079 In situ method, British Patent No. 930422, US Pat. No. 3,111,407 spray drying method, British Patent No. 952807, US Pat. No. 967074 specification, etc. 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.

The image recording layer of the present invention is applied by preparing 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 image recording layer of the present invention can also 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.

Further, the coating mass (solid content) of the image recording layer on the support obtained after coating and drying varies depending on the use, but generally 0.3 to 3.0 g / m ² is preferable. Within this range, good sensitivity and good film properties of the image recording layer can be obtained.
Various methods can be used as 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.

[Support]
The support used for the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, 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 foreign 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 is easy to improve hydrophilicity and secure adhesion between the image recording 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 cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. 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.

  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 with 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 with the image recording 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 image recording layer is provided on the undercoat layer. The undercoat layer enhances the adhesion between the support and the image recording layer in the exposed area, and in the unexposed area, the image recording layer is easily peeled off from the support. Will improve.
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. Preferable examples include phosphorus compounds having an ethylenic double bond reactive group described in the publication. A compound having a polymerizable group such as a methacryl group or an allyl group and a support adsorbing group such as a sulfonic acid group, a phosphoric acid group or a phosphoric acid ester is also preferred. Furthermore, a compound obtained by adding a hydrophilicity-imparting group such as an ethyleneoxy group to this compound is also suitable.
Coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / m ^2, and more preferably 1 to 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.

[Protective layer]
In the lithographic printing plate precursor according to the present invention, in order to improve white light safety, it is preferable not to include a protective layer for the purpose of blocking oxygen. In order to prevent ablation, a protective layer can be provided on the image recording layer as necessary.

Examples of the material used for the protective layer include water-soluble polymer compounds. Specific examples include water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid.
As long as the polyvinyl alcohol contains an unsubstituted vinyl alcohol unit, a part thereof may be substituted with an ester, an ether or an acetal, and a part may have other copolymerization components.
Specific examples of the polyvinyl alcohol include those having a hydrolysis degree of 71 to 100 mol% and a polymerization degree in the range of 300 to 2400. Specifically, for example, PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA manufactured by Kuraray Co., Ltd. -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, and L-8.

As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the (co) polymer Mass% can be added.

  In addition, adhesion of the protective layer to the image area, scratch resistance, and the like are extremely important in handling the lithographic printing plate precursor. That is, when a hydrophilic protective layer containing a water-soluble polymer compound is laminated on an oleophilic image recording layer, the protective layer is likely to be peeled off due to insufficient adhesion. On the other hand, various proposals have been made to improve the adhesion between the image recording layer and the protective layer. For example, JP-A-49-70702 and British Patent Application No. 1303578 disclose an acrylic emulsion, a water-insoluble vinylpyrrolidone-vinyl acetate copolymer, etc. 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 an image recording layer. Any of these known techniques can be used in the present invention.

  Furthermore, other functions can be imparted to the protective layer. For example, by adding a colorant (for example, a water-soluble dye) that is excellent in the transparency of light used for exposure and that can efficiently absorb light of other wavelengths, safe light is not caused. Suitability can be improved.

The coating amount of the protective layer in the present invention, 0~0.3g / m ² are suitable, in particular 0~0.1g / m ² are preferred.
The method for applying the protective layer is described in detail, for example, in US Pat. No. 3,458,311 and JP-B-55-49729.

[Lithographic printing method]
The planographic printing plate precursor of the present invention is image-exposed with a laser that emits light having a wavelength of 250 nm to 420 nm. Specific examples of such a laser include 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), and a He—Cd laser (325 nm, 1 mW to 100 mW). ), As a solid-state laser, a quadruple wave (266 nm, 20 to 100 mW) of a 1064 nm oscillation mode-locked solid-state laser such as YAG, YVO _4, etc. 100 mW), a combination of a waveguide wavelength conversion element and AlGaInP, an AlGaAs semiconductor (300 nm to 350 nm, 5 mW to 100 mW), AlGaInN (350 nm to 470 nm, 5 mW to 100 mW), and others, a pulse laser As N ₂ laser (337 nm, pulse 0.1~10mJ), XeF (351nm, pulse 10~250mJ), YAG, 3 harmonic (355nm, 1~4W) of 1064nm oscillation mode-locked solid-state laser such as YVO _4, etc. Can be mentioned.

  In particular, a suitable laser among these is an AlGaInN semiconductor laser (commercially available InGaN-based semiconductor laser 375 nm or 405 nm, 5 to 100 mW), in terms of cost and high light intensity capable of increasing the polymerization rate and production. This is a 355 nm laser with high output in terms of the characteristics, and a 266 nm laser that has the smallest emission spectrum overlap of the white fluorescent lamp in terms of wavelength suitability and can be highly sensitive.

When these lasers are used, the pixel residence time is preferably as short as possible in order to minimize the competitive reaction with oxygen, and is preferably 1 millisecond or less. More preferably, it is 500 microseconds or less. The amount of energy is preferably 0.1 to 10 mJ / cm ² .

The exposure in an atmosphere having an oxygen concentration of 0.05% by volume or less according to the present invention can be performed with a printing plate exposure apparatus as shown in FIG. 1 and FIGS.
Hereinafter, these printing plate exposure apparatuses will be described in detail.

FIG. 1 is a side view showing a main configuration of a printing plate exposure apparatus according to an embodiment of the present invention.
A printing plate exposure apparatus 100 according to the present embodiment includes a planographic printing plate precursor (hereinafter also referred to as a light-sensitive material) containing portion 102 and an oxygen-free state for replacing the air in the light-sensitive material containing portion 102 with an inert gas. It is mainly comprised of the realization part 104 and the photosensitive material exposure means 106 which performs predetermined exposure to the photosensitive material 122. FIG.

  The photosensitive material container 102 is moved back and forth (in the direction of arrow A) by a flat transparent holding member 108 made of glass or the like and a moving mechanism (not shown), and is pressed and isolated (pressed) on the transparent holding member 108. The holding member 110 made of a rigid material to be released is disposed so as to surround both of them, and reciprocally rotates (in the direction of the arrow B) so as to seal and release the sensitive material housing portion 102. The side wall member 112 is mainly configured. Note that the other two surfaces of the side wall (two surfaces parallel to the paper surface in the figure) are fixedly installed.

  FIG. 1A shows a state in which the side wall member 112 corresponds to the loading and discharging of the photosensitive material 122 in which the transparent holding member 108 and the pressing member 110 are separated from each other, and FIG. The side wall member 112 shows a state corresponding to the time of exposure of the photosensitive material 122 in which the space between the transparent holding member 108 and the pressing member 110 is closed (the photosensitive material accommodating portion 102 is sealed).

  The oxygen-free state realization unit 104 includes an inert gas cylinder such as nitrogen (or a generation device thereof, represented by a cylinder below) 114, an oxygen cutoff time control unit 116 that controls the operation of the inert gas cylinder 114, and the inert gas cylinder 114. From a gas ejection nozzle 118 for sending an inert gas supplied from an active gas cylinder 114 into the light-sensitive material storage unit 102, and an exhaust nozzle 120 for discharging the gas from the light-sensitive material storage unit 102 after the exposure is completed. Composed.

  Here, with respect to the gas ejection nozzle 118 for feeding the inert gas into the photosensitive material accommodating portion 102, for example, in order to quickly replace the air in the photosensitive material accommodating portion 102, the width direction of the sensitive material ( It is preferable to consider such as arranging a plurality in a direction perpendicular to the drawing sheet. In addition, the exhaust nozzle 120 is preferably set to the minimum necessary cross-sectional size in order to prevent the inert gas from being lost after the replacement.

  The photosensitive material exposure means 106 is a general known scan for performing predetermined exposure on the image recording layer (the upper surface in the drawing of the photosensitive material 122) 124 of the photosensitive material 122 loaded in the photosensitive material container 102. This is a beam type exposure apparatus, in which an image recording layer 124 of a plate-shaped photosensitive material 122 is two-dimensionally scanned and exposed by a laser beam modulated based on image data to be recorded. However, the present invention is not limited to this.

  In the printing plate exposure apparatus 100 according to the present embodiment, first, the space between the transparent holding member 108 and the pressing member 110 is opened, and the side wall member 112 is opened, so that the sensation to be exposed in the light-sensitive material container 102 is exposed. After the material 122 is loaded, the space between the transparent holding member 108 and the pressing member 110 is closed, the side wall member 112 is rotated, and the photosensitive material container 102 is sealed by the packing 112a. Thereafter, in accordance with a preset inert gas supply pattern (details will be described later), the inert gas is supplied from the inert gas cylinder 114 under the control of the oxygen shut-off time control means 116, and the sensitivity is increased. Inert gas replacement of the air in the material container 102 is performed.

  When the inert gas replacement is completed after the elapse of a predetermined time, the photosensitive material exposure unit 106 performs a predetermined scanning beam exposure on the photosensitive material 122 loaded in the photosensitive material accommodating portion 102. Here, even during this exposure, the supply of the inert gas from the inert gas cylinder 114 is continued under the control of the oxygen cutoff time control means 116. Further, after a predetermined time has passed after the exposure is completed, the supply of the inert gas is also stopped under the control of the oxygen cutoff time control means 116, and the gap between the transparent holding member 108 and the pressing member 110 is opened. Then, the side wall member 112 is opened, and the inside of the light-sensitive material accommodating portion 102 is returned to a normal air atmosphere.

The above is the main configuration and operation outline of the printing plate exposure apparatus 100 according to the embodiment.
Hereinafter, an example of a method for producing a printing plate according to the present invention performed using such a printing plate exposure apparatus 100 will be described.

  FIG. 2 is an operation flowchart showing an outline of a printing plate manufacturing method using the printing plate exposure apparatus 100 according to the embodiment. In the printing plate manufacturing method described below, as shown in FIG. 2, first, the space between the transparent holding member 108 and the pressing member 110 is opened, the side wall member 112 is opened, and the inside of the photosensitive material container 102 is opened. The photosensitive material 122 to be exposed is loaded so that the image recording layer 124 is the upper surface (step 202, this situation is indicated by the arrow C in FIG. 1).

Next, the space between the transparent holding member 108 and the pressing member 110 is closed, the side wall member 112 is sealed, and the replacement of the air in the light-sensitive material accommodating portion 102 with an inert gas is started (step 204, this The situation is indicated by the arrow D in FIG. This operation is all performed under the control of the oxygen cutoff time control means 116.
In other words, the oxygen cutoff time control means 116 is preset with oxygen cutoff time data before and after the exposure to the photosensitive material 122. Based on this data, first, here, the air in the photosensitive material accommodating portion 102 is first set. That is, the replacement with the inert gas is started.

  When the preset predetermined time elapses after the replacement of the air in the photosensitive material container 102 with the inert gas has started, it is assumed that the replacement with the inert gas has substantially ended, and the photosensitive material exposure unit 106 Thus, a predetermined scanning beam exposure is performed on the photosensitive material 122 (actually, the image recording layer 124) (step 206). Needless to say, the exposure performed here is so-called imagewise exposure based on image data for producing a printing plate.

  After the exposure in the above step 206 is completed, the supply of the inert gas from the inert gas cylinder 114 is further performed based on the oxygen interruption duration time after the completion of the exposure set in the oxygen interruption time control means 116 in advance. When the predetermined time has elapsed (step 208), the supply of the inert gas from the gas cylinder 114 is stopped, the side wall member 112 is returned to the open state, and the photosensitive material container 102 is sealed. The state is released (step 210).

  In this way, the exposed state of the photosensitive material 122 loaded in the photosensitive material accommodating portion 102 can contain oxygen in the image recording layer 124 by releasing the sealed state of the photosensitive material accommodating portion 102. Therefore, the photosensitivity beyond this level is substantially lost, and after that, it becomes possible to handle in the bright room. Therefore, the operator sets the photosensitive material 122 in this state on a predetermined printing machine in order to develop it on the machine (step 212).

  In the on-press development step of Step 212, for example, ink and dampening water are simultaneously supplied to the photosensitive material 122 set in the printing machine, as is conventionally performed, and the printing machine is operated to perform a normal operation. By performing the same operation as the printing operation, so-called on-press development is performed, and the production of the printing plate is completed at this point.

According to the method for preparing a printing plate shown in the above examples, even when using a printing plate precursor that does not have an oxygen blocking layer, forms a latent image by photopolymerization, and develops on a printing machine, A printing plate preparation method from a printing plate precursor that can be entirely performed in a bright room can be realized.
And the printing plate exposure apparatus 100 shown to the said embodiment is a printing plate exposure apparatus which can be used suitably in order to implement | achieve this method.

Here, a modification of the printing plate manufacturing method shown above will be described.
In the printing plate manufacturing method shown in the above-described embodiments, the time required for the replacement of the air in the light-sensitive material container 102 with the inert gas substantially before the exposure of the light-sensitive material 122 starts. The oxygen blocking operation is started, and the replacement operation with the inert gas is continued for a time substantially corresponding to the time required for the oxygen to penetrate into the image recording layer 124 of the photosensitive material 122 even after the exposure is completed. It is really necessary to block oxygen from the light-sensitive material 122 during exposure of the light-sensitive material, that is, a period in which radicals for photopolymerization generated in the light-sensitive material exist.

  Therefore, any or all of the oxygen blocking operation before the start of exposure or the oxygen blocking operation after the end of exposure can be omitted. In this case, however, it is needless to say that the determination as to whether or not omission is possible is preferably made based on the results of studies by detailed experiments and the like.

Further, in the printing plate manufacturing method shown above, an example in which the oxygen shut-off operation is realized by replacing the air in the light-sensitive material container 102 with an inert gas is shown. Needless to say, this can also be realized by removing substantially all of the air in the unit 102 (actually, oxygen).
In addition, the oxygen blocking operation is first performed in two stages: a first step of removing substantially all of the air in the light-sensitive material container 102 and a second step of introducing an inert gas after removing the air. A method of formulating can also be used.

Hereinafter, some other embodiments of the printing plate exposure apparatus that can be used in place of the printing plate exposure apparatus 100 will be described.
Each of these printing plate exposure apparatuses realizes a printing plate exposure apparatus that can be suitably used for the direct plate making as described above, which is easy to operate and does not cause an increase in running cost.

  FIG. 3 is a side view showing a main configuration of a printing plate exposure apparatus 300 according to another embodiment of the present invention. The printing plate exposure apparatus 300 according to the present embodiment has a configuration that can be called an improved version of the printing plate exposure apparatus 100 shown in FIG. The printing plate exposure apparatus 100 shown in FIG. 1 is different from the printing plate exposure apparatus 100 in that the pressing member 310 of the photosensitive material container 302 is provided with a buffer layer 310a made of a flexible material such as rubber or gel on a rigid material. It is in the point to.

In the printing plate exposure apparatus 300 according to the present embodiment, since the holding member 310 is provided with the buffer layer 310a as described above, the volume of the gap around the photosensitive material generated when the pressing member 310 is pressed against the photosensitive material 322. As a result, the effect of removing air or replacing with an inert gas can be obtained more reliably.
In FIG. 3, the same constituent elements as those of the printing plate exposure apparatus 100 shown in FIG. 1 are denoted by the related numbers to which 200 is added, and detailed description thereof is omitted.

  FIG. 4 is a side view showing the main configuration of a printing plate exposure apparatus 400 according to still another embodiment of the present invention. The printing plate exposure apparatus 400 according to the present embodiment has a configuration that can be called a modification of the printing plate exposure apparatus 100 shown in FIG. That is, the difference from the printing plate exposure apparatus 100 shown in FIG. 1 is that substantially all of the air in the photosensitive material accommodating portion 402 is removed instead of air replacement with an inert gas.

  That is, the printing plate exposure apparatus 400 according to the present embodiment is an oxygen-free state in which the printing plate exposure apparatus 100 shown in FIG. 1 includes an inert gas cylinder 114 and an oxygen cutoff time control means 116 that controls the operation thereof. The realization unit 104 is provided to replace the air in the light-sensitive material accommodation unit 102 with an inert gas, whereas the inert gas ejection nozzle 418 is used as a degassing port by the vacuum pump 426. Is.

Thereby, in the printing plate exposure apparatus 400 according to the present embodiment, there is an effect that it is possible to form an oxygen-blocking atmosphere at a relatively low cost by the method of removing the air in the photosensitive material container 402. can get.
In FIG. 4, the same components as those of the printing plate exposure apparatus 100 shown in FIG. 1 are denoted by the related numbers with 300 added thereto, and detailed description thereof is omitted.

  FIG. 5 is a side view showing a modification of the printing plate exposure apparatus 400 according to the embodiment shown in FIG. The printing plate exposure apparatus 500 according to the present embodiment uses a pressing member 510 provided with a roller 510a made of an elastic body such as rubber, instead of the pressing member 410 of the printing plate exposure apparatus 400 shown in FIG. It is characterized by a point.

As a result, in the printing plate exposure apparatus 500 according to the present embodiment, the photosensitive material 522 loaded in the photosensitive material storage unit 502 can be loaded and discharged more smoothly, and the photosensitive material 522 is loaded and discharged. Since the degree of opening of the pressing member 510 of the photosensitive material accommodating portion 502 at that time can be reduced, an effect that the time required for the photosensitive material replacement can be shortened can be obtained.
In FIG. 5, the same components as those of the printing plate exposure apparatus 400 shown in FIG. 4 are indicated by adding related numbers to which 100 is added, and detailed description thereof is omitted.

  Up to now, an example of a so-called flat-bed type printing plate exposure apparatus in which a photosensitive material is set on a flat plate has been described, but in the following, a so-called drum-type printing plate exposure apparatus having a drum-type photosensitive material holding unit Give an example. As is well known, drum-type printing plate exposure apparatuses include an inner drum type (method of exposing from the inner surface of the drum) and an outer drum type (method of exposing from the outer surface of the drum). Take an example.

  FIGS. 6A to 6D show an embodiment of an inner drum type printing plate exposure apparatus, and are sectional views in a state where a drum type photosensitive material holding section is cut along a plane perpendicular to the central axis thereof. Is shown. 6 (a) to 6 (d) respectively show before (a) loading of the photosensitive material, during loading of the photosensitive material (b), during preparation for degassing after loading of the photosensitive material (c), and during degassing (d). Indicates the situation.

  The printing plate exposure apparatus 600 according to the present embodiment includes a transparent holding member 608 formed of a glass cylinder with a part cut away, and a flexible pressing member 610 disposed outside the transparent holding member 608. A feed / winding mechanism, an exhaust mechanism (vacuum pump 626) for removing air in a sealed space (details will be described later) formed by both, and a rotation disposed inside the transparent holding member 608 It is mainly composed of laser beam scanning exposure means 606 using a mirror (spinner mirror).

  The feeding / winding mechanism of the pressing member 610 is configured so that the pressing member 610 can be fed and wound at an arbitrary position between both ends thereof, and can be driven in the same direction or in different directions. It is configured. As a result, the feeding / winding mechanism of the pressing member 610 receives the loaded photosensitive material 622 and conveys it to a predetermined position, and further, at that position, the photosensitive material 622 is made transparent by cooperation with the exhaust mechanism. It can be held in a sealed space between the holding member 608.

  In the printing plate exposure apparatus 600 according to the present embodiment, the photosensitive material 622 supplied with the image recording layer 624 on the transparent holding member 608 side (that is, the inner surface side) is provided with a feeding / winding mechanism for the pressing member 610. Received by driving in the direction of the arrow (FIG. 6 (a)), transported as indicated by arrows E and F to a predetermined position suitable for exposure by the scanning exposure means 606 ((b) to (d)). The space (sealed space) formed between the transparent holding member 608 holding the photosensitive material 622 in a state is evacuated by the cooperative action with the exhaust mechanism.

  Thus, after the air around the photosensitive material 622 loaded at a predetermined position is substantially exhausted, the scanning exposure means 606 performs general laser beam scanning exposure on the photosensitive material 622. Is called. It is preferable that the evacuated state (that is, the oxygen-blocked state) in the sealed space as described above is maintained until the exposure is completed, and further until a predetermined time after the exposure is completed.

Thereby, in the printing plate exposure apparatus 600 according to the present embodiment, even when the drum-type transparent holding member 608 is used, it is possible to remove substantially all of the air in the light-sensitive material storage unit 602. The effect that the exposure of the loaded photosensitive material 622 in an oxygen-blocking environment can be performed reliably and easily is obtained.
In FIG. 6, the same components as those of the printing plate exposure apparatus 100 shown in FIG. 1 are denoted by the related numbers added with 500, and detailed description thereof is omitted.

  Next, FIGS. 7A and 7B show an embodiment of an outer drum type printing plate exposure apparatus, and FIG. 7A is a plane perpendicular to the central axis of the drum type photosensitive material holding part. Sectional drawing of the state cut | disconnected by (4), (b) has shown in sectional drawing of the state cut | disconnected by the plane which passes along the same central axis. 7 (a) and 7 (b) are a schematic perspective view (a) showing a photosensitive material loading state and a diagram (b) for explaining a deaeration operation after loading the photosensitive material, respectively.

  The printing plate exposure apparatus 700 according to the present embodiment includes a transparent holding member 708 formed of a glass cylinder, an inner cylindrical flexible pressing member 710 disposed inside the transparent holding member 708, and both An exhaust mechanism (having a vacuum pump not shown) for removing air in a sealed space (details will be described later) formed by the laser beam, and laser beam scanning exposure means arranged outside the transparent holding member 708 706 is mainly composed.

  Here, both end portions of the transparent holding member 708 are closed by cap-like closing members 728a and 728b, and one of them, for example, 728b, is between the transparent holding member 708 and the holding member 710 described above. An exhaust port 732a used for removing the air in the circumferential gap 730 formed in is provided, and this exhaust port is connected to the aforementioned vacuum pump. The closing member 728b is provided with a conduction port 732b for maintaining the inside of the pressing member 710 at atmospheric pressure.

  With this configuration, in the printing plate exposure apparatus 700 according to the present embodiment, the photosensitive material 722 is loaded into the gap 730 (in the direction of arrow G), and the gap is released from the exhaust port 732a by the vacuum pump described above. When the air in 730 is removed, the pressing member 710 presses the photosensitive material 722 in the direction of the transparent holding member 708 by the atmospheric pressure applied to the inside thereof through the conduction port 732b, and securely holds the photosensitive material 722. At the same time, the surrounding vacuum state can be reliably maintained.

As described above, after substantially all the air around the photosensitive material 722 is exhausted, the scanning exposure means 706 performs laser beam scanning exposure on the photosensitive material 722. As described above, it is preferable that the evacuated state (oxygen-blocked state) in the sealed space (gap 730) is maintained until the exposure is completed, and further, until a predetermined time after the exposure is completed. .

  Thereby, in the printing plate exposure apparatus 700 according to the present embodiment, even when the drum-type transparent holding member 708 is used, it is possible to remove substantially all of the air in the photosensitive material accommodating portion 702, An effect is obtained that exposure of the loaded photosensitive material 722 in an oxygen-blocked environment can be performed reliably and easily.

  In the printing plate exposure apparatuses 600 and 700 shown in the above embodiment, the exhaust mechanism can be replaced with an air replacement mechanism in the light-sensitive material container 702 using an inert gas. It goes without saying that a more reliable oxygen-blocking environment can be realized with this configuration.

  Each of the above embodiments is merely an example of the present invention, and the present invention is not limited to the above embodiment, and various modifications and changes can be made without departing from the spirit of the present invention. Needless to say, improvements may be made.

  For example, in the printing plate exposure apparatus using the oxygen-blocking method according to the above-described embodiment, the transparent holding member that supports the photosensitive material is configured by an opaque member, and conversely, the pressing member that presses the photosensitive material against the supporting member is damaged. It is possible to make exposure in an oxygen-blocking environment by using a transparent sheet or the like that is less likely to generate and removing the air between them.

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

[Example 1]
(1) Production of support Al: 99.5% by mass or more, Fe: 0.30% by mass, Si: 0.10% by mass, Ti: 0.02% by mass, Cu: 0.013% by mass The remainder was cast by subjecting a molten JIS A1050 aluminum alloy, which is an inevitable impurity, to cleaning treatment. As the cleaning treatment, degassing treatment was performed to remove unnecessary gas such as hydrogen in the molten metal, and further ceramic tube filter treatment was performed. The casting method was a DC casting method. The surface of the ingot having a thickness of 500 mm was chamfered by 10 mm, and homogenized at 550 ° C. for 10 hours so that the intermetallic compound would not become coarse. Subsequently, it was hot-rolled at 400 ° C., subjected to intermediate annealing at 500 ° C. for 60 seconds in a continuous annealing furnace, and then cold-rolled to obtain an aluminum rolled plate having a thickness of 0.30 mm. By controlling the roughness of the rolling roll, to control the center line average roughness R _a after cold rolling to 0.2 [mu] m. Then, it applied to the tension leveler in order to improve planarity. The obtained aluminum plate was subjected to the following surface treatment.

In order to remove the rolling oil on the surface of the aluminum plate, after degreasing at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution, three bundled nylon brushes having a bristle diameter of 0.3 mm and the median The aluminum surface was grained using a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a diameter of 25 μm and thoroughly washed with water. This plate was etched by being immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C for 9 seconds, washed with water, further immersed in 20 mass% nitric acid at 60 ° C for 20 seconds, and washed with water. The etching amount of the grained surface at this time was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time is a 1% by mass aqueous solution of nitric acid (containing 0.5% by mass of aluminum ions), a liquid temperature of 5
It was 0 ° 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, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an 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 direct current anodized film of 2.5 g / m ² at a current density of 15 A / dm ² using 15% sulfuric acid (containing 0.5% by mass of aluminum ions) as an electrolyte, then washed with water, dried, Then, it was treated with an aqueous 2.5 mass% sodium silicate solution at 30 ° C for 10 seconds. The centerline average roughness (Ra) of this substrate was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.

(2) Preparation of lithographic printing plate precursor An undercoat layer coating solution (1) having the following composition was coated on the support using a bar having a liquid volume of 7.5 ml / m ² , Oven dried in seconds. On top of that, an image recording layer coating solution (1) having the following composition was bar coated, followed by oven drying at 70 ° C. for 60 seconds to form an image recording layer having a dry coating mass of 1.0 g / m ² and lithographic printing. An original plate (1) was obtained.

<Undercoat layer coating solution (1)>
・ 300 g of water
・ Methanol 2700g
-The following compound C-1 1.45g

<Image recording layer coating solution (1)>
・ The following polymerization initiator (1) 0.3 g
・ The following binder polymer (1) (average molecular weight 80,000) 6.0 g
・ Polymerizable compound 12.4g
Isocyanuric acid EO-modified triacrylate (M-315 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 3.0g
・ Thermal polymerization inhibitor 0.1g
N-nitrosophenylhydroxylamine aluminum salt 0.1 g of tetraethylammonium chloride
・ 0.1 g of the following fluorosurfactant (1)
・ Methyl ethyl ketone 70.0g

[Example 2]
A lithographic printing plate precursor (2) is obtained in the same manner as in the production of the lithographic printing plate precursor (1) except that the image recording layer coating solution (1) is changed to an image recording layer coating solution (2) having the following composition. It was.

<Image recording layer coating solution (2)>
・ The following polymerization initiator (1) 0.3 g
・ The following sensitizer (1) 0.45 g
・ The following binder polymer (1) (average molecular weight 80,000) 6.0 g
・ Polymerizable compound 12.4g
Isocyanuric acid EO-modified triacrylate (M-315 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 3.0g
・ Thermal polymerization inhibitor 0.1g
N-nitrosophenylhydroxylamine aluminum salt 0.1 g of tetraethylammonium chloride
・ 0.1 g of the following fluorosurfactant (1)
・ Methyl ethyl ketone 70.0g

Example 3
A lithographic printing plate precursor (3) was obtained in the same manner as the preparation of the lithographic printing plate precursor (2) except that the polymerization initiator (1) was changed to the polymerization initiator (2) shown below.

Example 4
A lithographic printing plate precursor (4) was obtained in the same manner as in the production of the lithographic printing plate precursor (2) except that the polymerization initiator (1) was changed to the following polymerization initiator (3).

Example 5
A lithographic printing plate precursor (5) was obtained in the same manner as the preparation of the lithographic printing plate precursor (2) except that the sensitizer (1) was changed to the following sensitizer (2).

Example 6
A lithographic printing plate precursor (6) was obtained in the same manner as in the production of the lithographic printing plate precursor (5) except that the polymerization initiator (1) was changed to the polymerization initiator (2).

Example 7
A lithographic printing plate precursor (7) was obtained in the same manner as in the production of the lithographic printing plate precursor (5) except that the polymerization initiator (1) was changed to the polymerization initiator (3).

Example 8
A lithographic printing plate precursor (8) is obtained in the same manner as in the production of the lithographic printing plate precursor (2) except that the image recording layer coating solution (2) is changed to an image recording layer coating solution (3) having the following composition. It was.

<Image recording layer coating solution (3)>
・ The above polymerization initiator (2) 0.3 g
-0.45 g of the above sensitizer (1)
-Compound (A-85) having a carboxylic acid group 0.3 g
・ The following binder polymer (1) (average molecular weight 80,000) 6.0 g
・ Polymerizable compound 12.4g
Isocyanuric acid EO-modified triacrylate (M-315 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 3.0g
・ Thermal polymerization inhibitor 0.1g
N-nitrosophenylhydroxylamine aluminum salt 0.1 g of tetraethylammonium chloride
・ 0.1 g of the following fluorosurfactant (1)
・ Methyl ethyl ketone 70.0g

Example 9
A lithographic printing plate precursor (9) is obtained in the same manner as in the production of the lithographic printing plate precursor (2) except that the image recording layer coating solution (2) is changed to an image recording layer coating solution (4) having the following composition. It was.

<Image recording layer coating solution (4)>
・ 0.3 g of the above polymerization initiator (1)
-0.45 g of the above sensitizer (1)
・ Binder polymer (1) (average molecular weight 80,000) 3.0 g
-Polymerizable compound 6.2g
Isocyanuric acid EO-modified triacrylate (M-315 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 3.0g
・ Thermal polymerization inhibitor 0.1g
N-nitrosophenylhydroxylamine aluminum salt 0.1 g of tetraethylammonium chloride
・ 0.1 g of the above-mentioned fluorosurfactant (1)
・ The following microcapsule (1) (in terms of solid content) 10.0 g
・ Methyl ethyl ketone 35.0g
・ 3-methoxy-2-propanol 35.0 g
・ Water 10.0g

(Synthesis of microcapsule (1))
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemical Co., Ltd., Takenate D-110N) 10 g, pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., SR444) 3.15 g, 1 g of 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane (ODB manufactured by Yamamoto Kasei Co., Ltd.) and 0.1 g of Pionin A-41C (manufactured by Takemoto Oil & Fat Co., Ltd.) Dissolved in 17 g. 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 (1) thus obtained was diluted with distilled water so that the solid content concentration became 20% by mass. The average particle size was 0.24 μm.

Example 10
A lithographic printing plate precursor (10) was obtained in the same manner as in the production of the lithographic printing plate precursor (9) except that the polymerization initiator (1) was changed to the polymerization initiator (2).

Example 11
A lithographic printing plate precursor (11) was obtained in the same manner as in the production of the lithographic printing plate precursor (9) except that the polymerization initiator (1) was changed to the polymerization initiator (3).

[Comparative Example 1]
The lithographic printing plate precursor is the same as the production of the lithographic printing plate precursor (1) except that the polymerization initiator (1) used for the production of the lithographic printing plate precursor (1) is changed to the following polymerization initiator (4). (12) was obtained.

[Comparative Example 2]
A lithographic printing plate precursor is prepared in the same manner as the production of the lithographic printing plate precursor (9) except that the polymerization initiator (1) used for the production of the lithographic printing plate precursor (9) is changed to the polymerization initiator (4). (13) was obtained.

[Comparative Example 3]
The following protective layer coating solution (1) is applied from above the lithographic printing plate precursor (2) so that the dry coating mass is 1.0 g / m ^2, and dried at 120 ° C. for 1 minute to obtain a lithographic printing plate precursor. (14) was obtained.

<Protective layer coating solution (1)>
Polyvinyl alcohol (saponification degree 95 mol%, polymerization degree 800) 40 g
Polyvinylpyrrolidone (molecular weight 50,000) 5g
Poly (vinyl pyrrolidone / vinyl acetate (1/1)) molecular weight 75,5 g
950g of water

[Comparative Example 4]
From the top of the lithographic printing plate precursor (9), the protective layer coating solution (1) is applied so that the dry coating weight is 1.0 g / m ^2, and dried at 120 ° C. for 1 minute to obtain a lithographic printing plate precursor ( 15) was obtained.

[Evaluation of planographic printing plate precursor]
<Sensitivity>
The obtained lithographic printing plate precursor was attached to the printing plate preparation apparatus shown in FIG. After confirming that the oxygen concentration reached 0.05% by volume, exposure was performed with a 375 nm semiconductor laser under the conditions of an output of 2 mW, an outer drum with a peripheral length of 900 mm, a drum rotation speed of 800 rpm, and a resolution of 2400 dpi. Inert gas replacement was stopped 30 seconds after exposure. The exposed exposed original plate was attached to a printing machine SOR-M manufactured by Heidelberg without developing, and dampening water (EU-3 (Etchi solution manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol = 1 / 89/10 (volume 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. After 100 sheets were printed and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were continuously printed. In the total 600th printed matter, the exposure amount with no unevenness in the ink density in the image area was measured as sensitivity.
Separately, the same evaluation was performed without replacing with an inert gas in the apparatus of FIG. The results are shown in Table 1.

<Safety of white light>
An unexposed lithographic printing plate precursor was placed under a white fluorescent lamp and placed under conditions where the light amount of 400 lux was obtained on the surface of the lithographic printing plate precursor, and exposure was performed. These lithographic printing plate precursors exposed to white light were subjected to development processing for those requiring development processing, and then attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg, and printed 100 sheets as described above. Thereafter, the exposure time was measured under a white fluorescent lamp where no ink smear occurred. The results are shown in Table 1. The longer this time, the better the white light safety.

  As is clear from the above results, it can be seen that the image forming method and the lithographic printing method (Examples 1 to 11) of the present invention have both sensitivity and white light safety.

(A), (b) is a side view which shows schematic structure of the printing plate exposure apparatus which concerns on one Embodiment. It is an operation | movement flowchart which shows the outline | summary of the manufacturing method of the printing plate which concerns on one Example. It is a side view which shows schematic structure of the printing plate exposure apparatus which concerns on other embodiment. (A), (b) is a side view which shows schematic structure of the printing plate exposure apparatus which concerns on other embodiment. It is a side view which shows schematic structure of the printing plate exposure apparatus which concerns on other embodiment. (A)-(d) is sectional drawing which shows schematic structure of the printing plate exposure apparatus which concerns on other embodiment. It is sectional drawing which shows schematic structure of the printing plate exposure apparatus which concerns on other embodiment, (a) is a perspective view, (b) is sectional drawing.

Explanation of symbols

100, 300, 400, 500, 600, 700 Printing plate exposure apparatus 102, 302, 402, 502 Sensitive material container 104, 304 Oxygen-free state realizing unit 106, 306, 406, 606, 706 Exposure means 108, 308, 408 , 508, 608, 708 Transparent holding member 110, 310, 410, 510, 610, 710 Pressing member 112, 312, 412, 512 Side wall member 112a, 312a, 412a, 512a Packing 114, 314 Inert gas cylinder 116, 316 Oxygen shut-off Time control means 118,318 Gas ejection nozzle 120,320 Exhaust nozzle 122,322,422,522,622,722 Photosensitive material (lithographic printing plate precursor)
124, 324, 424, 524, 624, 724 (sensitive material) image recording layer 202 to 212 Processing step 310a (pressing member) buffer layer 426, 526, 626 Vacuum pump 510a (pressing member) roller 728a, 728b Blocking Member 730 Crevice 732a Exhaust port 732b Conduction port A Holding member moving direction B Side wall member rotating direction C, E, F, G Sensitive material loading direction D Inert gas supply direction

Claims (8)

  A lithographic printing plate precursor comprising an image recording layer containing (A) a polymerization initiator and (B) a polymerizable compound and removable by printing ink and / or dampening water on a support, and having an oxygen concentration of 20 Laser light having a wavelength of 250 to 420 nm in an atmosphere having an oxygen concentration of 0.05 vol% or less and having a sensitivity of 100 times or more in an atmosphere having an oxygen concentration of 0.05 vol% with respect to the sensitivity in a volume% atmosphere. A lithographic printing plate precursor that can be used for image recording.   The lithographic printing plate precursor as claimed in claim 1, wherein the polymerization initiator is at least one selected from the group consisting of a sulfonium compound, an iodonium compound, and an oxime ester compound.   The lithographic printing plate precursor as claimed in claim 1 or 2, wherein the image recording layer further contains at least one sensitizer selected from an oxadiazole compound and a coumarin compound.   The lithographic printing plate precursor as claimed in any one of claims 1 to 3, wherein the image recording layer further contains a compound having a carboxylic acid group.   The lithographic printing plate precursor as claimed in any one of claims 1 to 4, wherein the addition amount of the polymerization initiator is in the range of 1 to 10 mass% with respect to the total mass of the image recording layer. The lithographic printing according to any one of claims 1 to 5, which has no protective layer on the image recording layer or has a protective layer having a coating mass of 0.3 g / m ² or less. Version original edition.   A lithographic printing plate precursor according to any one of claims 1 to 6, wherein the lithographic printing plate precursor is exposed in an atmosphere having an oxygen concentration of 0.05 vol% or less.   An image recording layer containing (A) a polymerization initiator and (B) a polymerizable compound is provided on the support, and the oxygen concentration is 0.05 vol% with respect to the sensitivity in an atmosphere having an oxygen concentration of 20 vol%. A lithographic printing plate precursor having a sensitivity of 100 times or more in an atmosphere is exposed imagewise in an atmosphere having an oxygen concentration of 0.05% by volume or less using a light source having a wavelength of 250 to 420 nm, and then a development processing step is performed. A lithographic printing method characterized by supplying printing ink and fountain solution without printing.

Images