JP5537881B2 - Planographic printing plate precursor and planographic printing method - Google Patents

Description

  The present invention relates to a lithographic printing plate precursor and a lithographic printing method using the same. More specifically, the present invention relates to a lithographic printing plate precursor and a lithographic printing method which can be developed with dampening water and ink on a printing press after exposure and have improved developability, printing durability and sensitivity.

In general, a lithographic printing plate comprises an oleophilic image area that receives ink in the printing process and a hydrophilic non-image area that receives dampening water. Lithographic printing utilizes the property that water and oil-based inks repel each other, so that the oleophilic image area of the lithographic printing plate is the ink receiving area, and the hydrophilic non-image area is dampened with the water receiving area (ink non-receiving area). In this method, a difference in ink adhesion is caused on the surface of the lithographic printing plate, and after ink is applied only to the image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, conventionally, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support is used. After exposure through a mask such as a film, development with an alkaline developer is performed to leave the image recording layer corresponding to the image area, and dissolve and remove the unnecessary image recording layer corresponding to the non-image area. And obtained a lithographic printing plate.

  Due to recent advances in this field, lithographic printing plates are now available with CTP (computer to plate) technology. That is, a lithographic printing plate can be obtained by scanning and exposing a lithographic printing plate precursor directly using a laser or a laser diode without a lith film, and developing it.

  Along with the above progress, problems related to the lithographic printing plate precursor have been changed to improvements in image formation characteristics, printing characteristics, physical characteristics and the like corresponding to the CTP technology. In addition, due to increasing interest in the global environment, environmental issues related to waste liquids associated with wet processing such as development processing have been highlighted as another issue related to lithographic printing plate precursors.

For the above environmental problems, simplification and no processing of development or plate making are directed. As one simple plate making method, a method called “on-press development” is performed. That is, after the exposure of the lithographic printing plate precursor, conventional development is not performed, but it is mounted on a printing machine as it is, and unnecessary portions of the image recording layer are removed at the initial stage of a normal printing process.
In addition, as a simple development method, a method called “gum development” in which unnecessary portions of the image recording layer are removed with a finisher or gum solution having a pH close to neutral instead of a conventional highly alkaline developer is also performed. ing.

  In the simplification of the plate making operation as described above, a system using a lithographic printing plate precursor and a light source that can be handled in a bright room or under a yellow light is preferable in terms of ease of work. A solid-state laser such as a semiconductor laser or a YAG laser emitting an infrared ray of 1200 nm is used. Further, a UV laser can be used.

  As a lithographic printing plate precursor capable of on-press development, for example, Patent Documents 1 and 2 disclose lithographic printing having an image recording layer (thermosensitive layer) containing a microcapsule enclosing a radically polymerizable compound on a hydrophilic support. The original edition is listed. Patent Document 3 describes a lithographic printing plate precursor in which an image recording layer (photosensitive layer) containing an infrared absorber, a radical polymerization initiator, and a radical polymerizable compound is provided on a support. Further, in Patent Document 4, on-press development is possible in which an image recording layer containing a radically polymerizable compound and a graft polymer having a polyethylene oxide chain in the side chain or a block polymer having a polyethylene oxide block is provided on a support. A lithographic printing plate precursor is described. Patent Document 5 describes a lithographic printing plate using a binder having an ethyleneoxy group.

  Thus, the method using a polymerization reaction has a feature that the image strength is relatively good because the chemical bond density of the image portion is high, but from a practical point of view, on-press developability, printing durability and None of the sensitivity was still inadequate.

Patent Document 6 discloses an alkali-soluble composition comprising an unsaturated group- and carboxyl group-containing epoxy resin in which a polycarboxylic acid or an anhydride thereof is added to an α, β-unsaturated monocarboxylic acid adduct of an epoxy resin. It is described that a blue-violet laser-sensitive composition using a resin can be used for a lithographic printing plate.
Patent Document 7 describes a photopolymerizable composition using an aromatic epoxy resin derivative having a polymerizable unsaturated group and an aprotic onium base.
Patent Document 8 discloses an unsaturated double compound of a reaction product (I) of an epoxy resin (a) having two or more epoxy groups in the molecule, dimethylolpropionic acid and an unsaturated group-containing monocarboxylic acid (b). Energy beam curable resin containing a reaction product (A) obtained by neutralizing a compound obtained by adding a compound (c) having an amino group having at least one active hydrogen to a part of the bond A composition is described.
Patent Document 9 discloses a photopolymerizable composition containing a resin obtained by reacting an unsaturated group-containing isocyanate compound with a novolak type epoxy resin to which a secondary amine is added.
Patent Document 10 adds a compound having an amino group having at least one active hydrogen to a part of an unsaturated double bond of a compound derived from an epoxy compound and a compound having an unsaturated double bond. An energy ray curable resin composition comprising a resin A obtained by neutralizing a compound obtained by the above process is described.

  The above-described techniques are insufficient to obtain a lithographic printing plate precursor excellent in on-press developability, printing durability and sensitivity.

JP 2001-277740 A JP 2001-277742 A JP 2002-287334 A US Patent Application Publication No. 2003/0064318 JP 2007-055224 A JP 2004-117857 A Japanese Patent No. 3481316 Japanese Patent Laid-Open No. 2-1858 Japanese Patent No. 2864070 JP-A-5-339330

  The present invention has been made in view of the above situation, and an object of the present invention is a lithographic printing plate precursor and a lithographic printing method capable of on-machine development with good on-machine developability, printing durability and sensitivity. Is to provide.

  As a result of intensive studies, the present inventor has been able to achieve the above object by using a modified epoxy resin having a hydrophilic functional group. That is, the present invention is as follows.

<1> A lithographic printing plate precursor having an image recording layer containing the following (A) to (C) on a support and capable of being developed with dampening water and ink on a printing press.
(A) Modified epoxy resin having at least one hydrophilic functional group selected from a polyalkylene oxide group, a sulfonic acid group, a sulfonic acid group, an amide group, an ammonium group and an amino group
(B) Infrared absorber
(C) radical polymerization initiator
<2> The lithographic printing plate precursor as described in <1>, wherein the modified epoxy resin having a hydrophilic functional group has an ethylenically unsaturated group.
<3> Modified epoxy resin (A-1) obtained by reacting the modified epoxy resin with a compound having an epoxy resin, a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin, and a hydrophilic functional group The lithographic printing plate precursor as described in <1> or <2> above, wherein
<4> The modified epoxy resin is obtained by reacting (1) an epoxy resin with a compound having a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin, and (2) a modified epoxy resin. <1> or <2>, which is a modified epoxy resin (A-2) obtained by reacting a compound having a functional group capable of reacting with a substituent in the resin and a hydrophilic functional group. Lithographic printing plate precursor.
<5> The modified epoxy resin is obtained by further reacting the modified epoxy resin (A-1) with a compound having a functional group capable of reacting with an epoxy group or a substituent in the resin (A-1). The lithographic printing plate precursor as described in <3> above, which is a modified epoxy resin (A-3).
<6> The functional group capable of reacting with an epoxy group or a substituent in the epoxy resin is selected from a carboxy group, an amino group, a hydroxy group, a mercapto group, an isocyanate group, a 1,3-diketo group, and an acid anhydride group. The lithographic printing plate precursor as described in any one of <3> to <5> above, wherein the lithographic printing plate precursor is a group.
<7> The functional group capable of reacting with the epoxy group or substituent in the modified epoxy resin (A-1) is a carboxy group, an amino group, a hydroxy group, a mercapto group, an isocyanate group, a 1,3-diketo group, and an acid. The lithographic printing plate precursor as described in <5> above, which is a group selected from an anhydride group.
<8> The lithographic printing according to any one of <1> to <7>, wherein the modified epoxy resin is a resin having a mass average molar mass (Mw) of 3,000 to 300,000. Version original edition.
<9> The lithographic printing plate precursor as described in any one of <1> to <8>, wherein the image recording layer further contains (D) a radical polymerizable compound.
<10> The lithographic printing plate precursor as described in any one of <1> to <9>, wherein the image recording layer further contains (E) polymer fine particles.
<11> The lithographic printing plate precursor as described in <10>, wherein the polymer fine particle is a microcapsule containing a compound having one or more ethylenically unsaturated groups.
<12> The lithographic printing plate precursor as described in <10>, wherein the polymer fine particles are fine particles of a polymer containing acrylonitrile as a monomer unit.
<13> The lithographic printing plate precursor as described in any one of <1> to <12>, further comprising a protective layer on the image recording layer.
<14> The lithographic printing plate precursor as described in <13>, wherein the protective layer contains a hydrophilic resin.
<15> The lithographic printing plate precursor as described in <13>, wherein the protective layer contains an inorganic stratiform compound.
<16> A lithographic printing method comprising exposing the image of the lithographic printing plate precursor according to any one of <1> to <15> imagewise, and then placing the lithographic printing plate precursor on a printing press to perform printing as it is. .
<17> A lithographic printing method comprising: placing the lithographic printing plate precursor according to any one of <1> to <15> above in a printing machine, exposing the image like the image, and printing the image as it is.
The present invention relates to the lithographic printing plate precursor and the lithographic printing method described in <1> to <17> above, but other matters are also described for reference.
1. A lithographic printing plate precursor having an image recording layer containing the following (A) to (C) on a support and capable of being developed with dampening water and ink on a printing press.
(A) Modified epoxy resin having a hydrophilic functional group (B) Infrared absorber (C) Radical polymerization initiator 2. The lithographic printing plate precursor as described in 1 above, wherein the modified epoxy resin having a hydrophilic functional group has an ethylenically unsaturated group.
3. 3. The lithographic plate as described in 1 or 2 above, wherein the hydrophilic functional group is at least one group selected from a polyalkylene oxide group, a sulfonic acid group, a sulfonic acid group, an amide group, an ammonium group and an amino group. A printing plate master.
4). The modified epoxy resin is a modified epoxy resin (A-1) obtained by reacting an epoxy resin with a compound having a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin and a hydrophilic functional group. The lithographic printing plate precursor as described in any one of 1 to 3 above.
5. In the modified epoxy resin obtained by reacting the modified epoxy resin with (1) a compound having a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin,
(2) Modified epoxy resin (A-2) obtained by reacting a compound having a hydrophilic functional group with a functional group capable of reacting with a substituent in the modified epoxy resin. The lithographic printing plate precursor as described in any one of the above items.
6). The modified epoxy resin is further added to the modified epoxy resin (A-1) and the resin (A-1).
5) The lithographic printing plate precursor as described in 4 above, which is a modified epoxy resin (A-3) obtained by reacting a compound having a functional group capable of reacting with an epoxy group or a substituent.
7). The functional group capable of reacting with an epoxy group or a substituent in the epoxy resin is a group selected from a carboxy group, an amino group, a hydroxy group, a mercapto group, an isocyanate group, a 1,3-diketo group, and an acid anhydride group. The lithographic printing plate precursor as described in any one of 4 to 6 above, wherein
8). The functional group capable of reacting with the epoxy group or substituent in the modified epoxy resin (A-1) is a carboxy group, an amino group, a hydroxy group, a mercapto group, an isocyanate group, a 1,3-diketo group, and an acid anhydride group. The lithographic printing plate precursor as described in 6 above, which is a selected group.
9. The modified epoxy resin has a mass average molar mass (Mw) of 3,000 to 300,000.
The lithographic printing plate precursor as described in any one of 1 to 8 above, wherein
10. The lithographic printing plate precursor as described in any one of 1 to 9 above, wherein the image recording layer further contains (D) a radical polymerizable compound.
11. The lithographic printing plate precursor as described in any one of 1 to 10 above, wherein the image recording layer further comprises (E) polymer fine particles.
12 12. The lithographic printing plate precursor as described in 11 above, wherein the polymer fine particle is a microcapsule containing a compound having one or more ethylenically unsaturated groups.
13. 12. The lithographic printing plate precursor as described in 11 above, wherein the polymer fine particles are fine particles of a polymer containing acrylonitrile as a monomer unit.
14 The lithographic printing plate precursor as described in any one of 1 to 13 above, further comprising a protective layer on the image recording layer.
15. 15. The lithographic printing plate precursor as described in 14 above, wherein the protective layer contains a hydrophilic resin.
16. The lithographic printing plate precursor as described in 14 above, wherein the protective layer contains an inorganic stratiform compound.
17. After exposing the lithographic printing plate precursor according to any one of 1 to 16 imagewise,
A lithographic printing method characterized in that it is installed on a printing press and printed as it is.
18. A lithographic printing method comprising: printing the lithographic printing plate precursor according to any one of 1 to 16 on an image-like basis after exposure to image printing.

  According to the present invention, it is possible to provide a lithographic printing plate precursor and a lithographic printing method capable of on-press development with good on-press developability, printing durability and sensitivity.

[Lithographic printing plate precursor]
The lithographic printing plate precursor according to the invention has an image recording layer containing the following components (A) to (C) on a support, and can be developed with dampening water and ink on a printing press.
(A) Modified epoxy resin having a hydrophilic functional group (B) Infrared absorber (C) Radical polymerization initiator Hereinafter, components and components of the lithographic printing plate precursor according to the invention will be described in detail.

(Image recording layer)
The image recording layer used in the present invention is a radical polymerization type image recording layer that can be developed on-press. As typical aspects of the on-machine developable image recording layer, (1) (A) a modified epoxy resin having a hydrophilic functional group, (B) an infrared absorber, (C) a radical polymerization initiator, and ( D) An embodiment containing a radical polymerizable compound, (2) (A) a modified epoxy resin having a hydrophilic functional group and an ethylenically unsaturated group, (B) an infrared absorber, and (C) a radical polymerization initiator And (3) (A) a modified epoxy resin having a hydrophilic functional group and an ethylenically unsaturated group, (B) an infrared absorber, (C) a radical polymerization initiator, and (D) a radical polymerizability An embodiment containing a compound can be given. Further, (E) polymer fine particles may be contained in the above-mentioned aspects (1), (2) and (3).
Below, each component which can be contained in an image recording layer is demonstrated one by one.

(A) Modified epoxy resin having a hydrophilic functional group The modified epoxy resin having a hydrophilic functional group used in the present invention is hydrophilic obtained by modifying a compound having at least two epoxy groups in the molecule. Any resin having a functional group can be suitably used.
Hereinafter, the modified epoxy resin having a hydrophilic functional group is simply referred to as a modified epoxy resin (A) or a resin (A).

Any compound having at least two epoxy groups in the molecule can be suitably used as long as it is a known epoxy resin. Specific examples of epoxy resins that can be used in the present invention include phenols; various alkylphenols such as o-cresol, m-cresol, p-cresol, and thymol; condensed aromatic phenols such as naphthol; bisphenol A and bisphenol F. , Novolak type epoxy resins obtained by the reaction of novolak resin, which is a reaction product of bisphenols such as bisphenol S, and aldehydes such as formaldehyde, and epihalohydrin: bisphenol A, bisphenol F, bisphenol S, brominated bisphenol A, etc. Bisphenol-type epoxy resin obtained by the reaction of bisphenols with epihalohydrin: polyols such as hydrogenated bisphenol A, glycerol, biphenol, bixylenol, and epihalohydrin Type epoxy resin obtained by reaction with bisphenol: epoxy resin obtained by reacting bisphenol type epoxy resin and / or polyol type epoxy resin with polyhydroxy compounds such as bisphenols, biphenol, bixylenol, hydrogenated bisphenol A, glycerol, etc. And its epihalohydrin modified: trisphenol methane type epoxy resin: tetraphenylol ethane type epoxy resin: aliphatic epoxy resin: alicyclic epoxy resin: glycidyl amine type epoxy obtained by reaction of primary or secondary amine with epihalohydrin Examples thereof include an isocyanuric acid type epoxy resin obtained by reacting a resin, triglycidyl isocyanurate and a polyhydroxy compound. Among these, novolac type epoxy resins, bisphenol type epoxy resins, polyol type epoxy resins, bisphenol type epoxy resins and epoxy resins obtained by condensing polyol type epoxy resins and polyhydroxy compounds, and their epihalohydrin modified products, trisphenol methane Type epoxy resin, tetraphenylolethane type epoxy resin, and isocyanuric acid type epoxy resin are more preferable.
Among these epoxy resins, an epoxy resin having a unit represented by the following general formula (1) or (2) is particularly preferable.

In the formula, A represents a divalent linking group, R _{1 to} R ₆ each independently represents a monovalent substituent, and * represents a unit linking part. A ring may be formed by any two of A and R _{1 to} R ₄ with the benzene ring, and a ring may be formed with R ₅ and R ₆ of the benzene ring.
Specific examples of A include a single bond, —CH ₂ —, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —O—, —S—, —SO ₂ —, and the following general formula. Examples include the linking group represented by (3).
R _{1 to} R ₆ are preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 24 carbon atoms, an aryl group having 6 to 24 carbon atoms, a nitro group, a cyano group, or an alkoxy having 1 to 12 carbon atoms. Group, an aryloxy group having 6 to 12 carbon atoms.

In formula (3), Ra and Rb have the same meaning as R ₁ and are connected to the benzene ring in formula (1) at the * part.
Specific examples of R _{1 to} R ₆ include a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and 2 to 12 carbon atoms. Alkynyl group, halogen atom, cyano group, nitro group, -OR ₇ , -SR ₇ , -NR ₇ R ₈ , -COOR ₇ , -COR ₇ (wherein R ₇ and R ₈ are each independently a hydrogen atom, An alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkynyl group having 2 to 12 carbon atoms).

  Specific examples of the epoxy resin used in the present invention are shown below. The present invention is not limited to these. In specific examples, G represents a hydrogen atom or a glycidyl group.

  As commercially available epoxy resins, “jER1002”, “jER1055”, “jER1009”, “jER1010”, “jER4007P”, “jER4110”, “jER4210”, “jER1256”, “jER4250”, “jER4275”, “jER154” ”,“ JER157S70 ”,“ jER1031S ”,“ jER872 ”,“ jERYX8034 ”,“ jERYX4000 series ”,“ jERYL6677 ”(manufactured by Japan Epoxy Resin Co., Ltd.),“ Sumiepoxy ESCN Series ”(manufactured by Sumitomo Chemical Co., Ltd.) , “EOCN series”, “EPPN series” (manufactured by Nippon Kayaku Co., Ltd.), “YDCN series”, “YDPN series”, “Epototo YD series”, “YDF series”, “YDB series”, “ "T series", "YH-300 series", "YH-434 series" (manufactured by Tohto Kasei Co., Ltd.), "Epicron series", "Epicron N-600 series", "Epicron N-700 series", "Epicron N" -800 series "," EPICLON EXA-4710 "," EPICLON EXA-4816 / EXA-4822 "," EPICLON EXA-4850 series "(manufactured by Dainippon Ink & Chemicals, Inc.)," Araldite ECN-1200 "," Araldite EPN-1100 series "(manufactured by Ciba Geigy Co., Ltd.), D.C. E. N. 400 series (manufactured by Dow Chemical Japan), SR-BBS, SR-TBA-400 (manufactured by Sakamoto Pharmaceutical Co., Ltd.), “NER-1302” (manufactured by Nippon Kayaku Co., Ltd.), “Adeka Resin EP -4100 Series "," Adeka Resin EP-4900 Series "," Adeka Resin EP-5100 Series "," Adeka Resin EPU Series "," Adeka Resin EPR Series "," Adeka Resin EP-6000 Series "(manufactured by ADEKA Corporation), etc. are also suitable. Can be used for Among these epoxy resins, an epoxy resin having at least one aromatic ring in the molecule is preferable, and two or more are particularly preferable.

  As the mass average molar mass (Mw) of the epoxy resin used in the present invention, any mass average molar mass epoxy resin can be used, but it is preferably 200 or more and 500,000 or less, more preferably 300 or more and 400,000 or less. 500 to 300,000 is particularly preferable. Moreover, as an epoxy equivalent, it is preferable that it is 0.1 mol or more with respect to 1 kg of resin. These epoxy resins may use only 1 type and may use 2 or more types together.

  The modified epoxy resin (A) used in the present invention can be suitably used as long as it is a resin having a hydrophilic functional group modified by modifying the epoxy resin as described above. A resin (A-1) obtained by reacting an epoxy resin such as a compound (a) having a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin and a hydrophilic functional group, (2) above An epoxy resin in the resin (C ′) is obtained by reacting an epoxy resin such as the above and a compound (b ′) having a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin. A resin (A-2) obtained by reacting a functional group capable of reacting with a group or substituent and a compound (c) having a hydrophilic functional group, (3) the resin (A-1) as described above, An agent capable of reacting with an epoxy group or a substituent in the resin (A-1) Resins obtained by reacting a compound having a group of (d) (A-3), is preferably either. You may perform reaction (2) or (3) repeatedly after reaction of (2) or (3).

  The “compound having a functional group capable of reacting with an epoxy group or a substituent in an epoxy resin and a hydrophilic functional group (a)” used in the present invention is a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin. Any compound having (a) and a hydrophilic functional group (a) can be suitably used.

  As the functional group (a), any epoxy group or substituent that exists in the epoxy resin (eg, a hydroxyl group, an ester group, an amino group, a carbonyl group, an acrylic group, a carboxy group, or the like) can be used. Can be preferably used, but a carboxy group, an amino group, a hydroxy group, a mercapto group, an isocyanate group, a 1,3-diketo group, an acid anhydride group, and an epoxy group are preferable, and a carboxy group, a hydroxy group, and an isocyanate group. More preferred are amino groups and acid anhydride groups.

As the hydrophilic functional group (A), any functional group capable of imparting hydrophilicity to the modified epoxy resin can be suitably used, but a polyalkylene oxide group, a sulfonic acid group, a sulfonic acid group, an amide group An ammonium group and an amino group are preferable in terms of hydrophilicity, and a polyalkylene oxide group, a sulfonic acid group, a sulfonic acid group, and an amide group are particularly preferable. The polyalkylene oxide group is particularly preferably a polyethylene oxide group having 4 to 200 carbon atoms and a polypropylene oxide group having 6 to 300 carbon atoms. The amide group represents —CONR ₁₁ R ₁₂ (R ₁₁ and R ₁₂ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, May be formed) is preferred. The ammonium group is —N ⁺ R ₁₃ R ₁₄ R ₁₅ (R ₁₃ , R ₁₄ and R ₁₅ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkenyl having 2 to 4 carbon atoms. And a functional group represented by any two may form a ring). The amino group represents —NR ₁₆ R ₁₇ (R ₁₆ and R ₁₇ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, May be formed) is preferred.

  As the compound (a) used in the present invention, any compound having at least one functional group (a) and one functional group (a) in the molecule can be preferably used. Specific examples of the compound (a) are shown below, but the present invention is not limited thereto.

  Only one type of compound (a) used in the present invention may be used, or two or more types may be used in combination.

The “compound (b) having a functional group capable of reacting with an epoxy group or a substituent in an epoxy resin” used in the present invention has at least a functional group (a) capable of reacting with an epoxy group or a substituent in the epoxy resin. Any compound having one compound can be suitably used.
Examples of the functional group (a) include the functional groups described above, and a carboxy group, a hydroxy group, an isocyanate group, an amino group, and a mercapto group are more preferable.

Specific examples of the compound (b) include acetic acid, propionic acid, 2-ethylhexanoic acid, cyclohexanecarboxylic acid, glycolic acid, lactic acid, benzoic acid, oleic acid, linoleic acid, monoethyl succinate, dimethyl citrate, and cinnamic acid. , Salicylic acid, methanol, isopropyl alcohol, stearyl allyl alcohol, butyl isocyanate, trimethyl-1,6-diisocyanatohexane, phenyl isocyanate, dodecylamine, dibenzylamine, N-methylaniline, dodecyl mercaptan, 2-mercaptobenzimidazole, etc. The present invention is not limited to these examples.
As the compound (b) used in the present invention, only one type may be used, or two or more types may be used in combination.

“Compound (c) having a functional group and a hydrophilic functional group capable of reacting with an epoxy group or a substituent in the resin (C ′) obtained by reacting the epoxy resin with the compound (b)” used in the present invention. Any compound that has at least one functional group (U) and hydrophilic functional group (A) capable of reacting with an epoxy group or a substituent in the resin (C ′) in the molecule is preferably used. be able to.
As the functional group (c), any epoxy group or substituent present in the resin (C ′) or a substituent that reacts with the substituent (eg, hydroxy group, ester group, amino group, carbonyl group, acrylic group, etc.) can be used. Can be preferably used, but a carboxy group, an amino group, a hydroxy group, a mercapto group, an isocyanate group, a 1,3-diketo group, an acid anhydride group, an ester group, and an acid halide group are preferable, a carboxy group, An isocyanate group, an amino group, an acid anhydride group, a mercapto group, and a 1,3-diketo group are more preferable.
Examples of the hydrophilic functional group (A) include the functional groups described above, and polyalkylene oxide groups, sulfonic acid groups, sulfonic acid groups, and amide groups are particularly preferable.

  Specific examples of the compound (c) include the compounds (a-1) to (a-28) described above, but the present invention is not limited thereto. Only one type of compound (c) used in the present invention may be used, or two or more types may be used in combination.

The “compound (d) having a functional group capable of reacting with an epoxy group or a substituent in the modified epoxy resin (A-1)” used in the present invention is an epoxy group or a substituent in the resin (A-1). Any compound having at least one functional group (d) capable of reacting in the molecule can be suitably used.
As the functional group (d), any substituent that reacts with a substituent (eg, a hydroxy group, an ester group, an amino group, a carbonyl group, an acrylic group, etc.) present in the resin (A-1) is suitable. Carboxy group, amino group, hydroxy group, mercapto group, isocyanate group, 1,3-diketo group, ester group, acid anhydride group, acid halide group are preferable, carboxy group, isocyanate group An amino group, an ester group, a mercapto group, and a 1,3-diketo group are more preferable. Specific examples of compound (d) include the specific examples of compound (b) described above, but the present invention is not limited thereto.
Only 1 type may be used for the compound (d) used for this invention, and 2 or more types may be used together.

  The modified epoxy resin (A) used in the present invention preferably has an ethylenically unsaturated group. Any ethylenically unsaturated group can be used as long as it is a carbon-carbon double bond that undergoes a polymerization reaction by a radical, but the functionalities represented by the following general formulas (4) to (6) The group is particularly preferred.

In the formula, Rc represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, —OR ₁₄ group, —SR ₁₄ group, —OCOR ₁₄ group, —OCONR ₁₄ R _15. Group, -OCOOR ₁₄ group, -OSO ₂ R ₁₄ group, -OPO (OR ₁₄ ) (OR ₁₅ ) group, -OPOR ₁₄ (OR ₁₅ ) group, -COR ₁₄ group, -COOR ₁₄ group, -NR ₁₄ R ₁₅ Group, -NR ₁₄ COR ₁₅ group, -NR ₁₄ COOR ₁₅ group, -NR ₁₄ CONR ₁₅ R ₁₆ group, -NR ₁₄ SO ₂ R ₁₅ group, -n (SO ₂ R ₁₄ ) (SO ₂ R ₁₅ ) group, _{-n (COR 14) (COR 15} ) _group, -SO _{2 R 14 group,} -SO _{3 R 14 groups, -PO (OR 14) (OR} 15) group _{(R 14, R 15, R} 16 are, Independently a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, and a monovalent substituent such as an alkynyl group), a hydrogen atom, a methyl group, point -CH 2 X _'is a radical polymerization reactivity Is preferable.
The alkyl group, alkenyl group, alkynyl group, and aryl group may have a substituent in the structure, and examples of the substituent include the monovalent substituent of Rc described above. The alkyl group, alkenyl group, and alkynyl group may be branched or may form a ring.
Examples of X ′ include the monovalent substituent of Rc described above, and include a halogen atom, cyano group, —OR ₁₄ group, —OCOR ₁₄ group, —OCONR ₁₄ R ₁₅ group, —OCOOR ₁₄ group, —NR ₁₄ R. ₁₅ groups, -NR ₁₄ COR ₁₅ group, -NR ₁₄ COOR ₁₅ group, -NR ₁₄ CONR ₁₅ R ₁₆ group, -SR ₁₄ group, -COOR ₁₄ group are particularly preferred.

As Rd and Re, the monovalent substituent of Rc described above can be mentioned independently, and a hydrogen atom, an alkyl group, or a —COOR ₁₄ group is preferable from the viewpoint of radical polymerization reactivity.
Examples of X include —O—, —S—, and —NR ₁₄ —, and —O— and —NR ₁₄ — are particularly preferable. Examples of R ₁₄ include the functional groups described above.
* Represents a site where the ethylenically unsaturated group represented by the formula (4) is linked to the resin (A).
Any two of R _C , Rd, Re, and X in formula (4) may form a ring.

In formula (5), examples of Rf and Rg include the monovalent substituents of Rc described above. A hydrogen atom and an alkyl group are preferable, and a hydrogen atom and an alkyl group having 1 to 6 carbon atoms are particularly preferable.
Examples of Rh, Ri, and Rj include the monovalent substituent of Rc described above, and a hydrogen atom, an alkyl group, a —COOR ₁₄ group, and a —CONR ₁₄ R ₁₅ group are preferable from the viewpoint of radical polymerization reactivity.
Examples of Y include —O—, —S—, —NR ₁₄ —, and —CR ₁₄ R ₁₅ —, and —O— and —NR ₁₄ — are particularly preferable. R ₁₄ and R ₁₅ have the same meanings as R ₁₄ and R ₁₅ in Rc described above.
* Represents a site where the ethylenically unsaturated group represented by the formula (5) is linked to the resin (A).
A ring may be formed by any two of Rf to Rj and Y in the formula (5).

In the formula (6), examples of Rk, Rl, and Rm include the monovalent substituent of Rc described above, and a hydrogen atom, an alkyl group, an aryl group, a —COOR ₁₄ group, and a —CONR ₁₄ R ₁₅ group are radically polymerized. It is preferable in terms of reactivity.
Examples of Z include —O—, —S—, —NR ₁₄ —, and —C ₆ H ₄ —, and —O— and —C ₆ H ₄ — are preferable from the viewpoint of radical polymerization reactivity.
* Represents a site where the ethylenically unsaturated group represented by the formula (6) is linked to the resin (A).
A ring may be formed by any two of Rk to Rm and Z in the formula (6).

As a method for introducing the ethylenically unsaturated group into the modified epoxy resin (A) used in the present invention, any one of the aforementioned compounds (a) to (d) further having the ethylenically unsaturated group is used. It is preferable to introduce by using.
Specific examples of the compounds (a) to (d) having an ethylenically unsaturated group used in the present invention are shown below, but the present invention is not limited thereto.

  The introduction amount of the ethylenically unsaturated group in the modified epoxy resin (A) used in the present invention is preferably 0.1 mol or more and 30 mol or less, and 0.2 mol or more and 20 mol per kg of the resin (A). It is more preferably no greater than mol, and particularly preferably no less than 0.3 mol and no greater than 10 mol. Two or more ethylenically unsaturated groups may be used in combination.

  The modified epoxy resin (A) used in the present invention is prepared by a conventionally known method. Specifically, the above-mentioned epoxy resin is acetone, methyl ethyl ketone, cyclohexanone, diethylene glycol ethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl acetate. , Butyl acetate, tetrahydrofuran, diisopropyl ether, chloroform, dichloromethane, tetrachloroethane, toluene, xylene, γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, dimethylsulfoxide , Tetraethylurea, sulfolane, propylene carbonate, 1-methoxy-2-propanol, etc. Tertiary amines such as ruamine and tribenzylamine, or quaternary ammonium salts such as tetramethylammonium chloride, methyltriethylammonium chloride, tetraethylammonium bromide, tetraethylammonium tosylate, tetrabutylammonium chloride, and trimethylbenzylammonium chloride. In the presence of a catalyst such as a phosphorus compound such as triphenylphosphine, or a stibine such as triphenylstibine, hydroquinone, hydroquinone monomethyl ether, methyl hydroquinone, 2,2,6,6-tetramethylpiperidine-1- In the presence of a thermal polymerization inhibitor such as oxyl and p-benzoquinone, the above compound (a) is added, and an addition reaction is usually performed at a temperature of 60 to 150 ° C, preferably 80 to 120 ° C. can get. Further, the resin obtained as described above can be obtained by dissolving the compound in an organic solvent and reacting the compound (d) with the presence of a thermal polymerization inhibitor if necessary.

  In addition, the above compound (b) is reacted with the above epoxy resin in the same manner to synthesize a resin (C ′), or the resin (C ′) is reprecipitated from a poor solvent or the solvent is distilled off. It can also be obtained by taking it out or the like and then dissolving it in another solvent and reacting the compound (c) with the presence of a thermal polymerization inhibitor if necessary.

The polystyrene-equivalent mass average molar mass (Mw) measured by gel permeation chromatography (GPC) of the resin (A) used in the present invention is preferably 3,000 to 300,000, more preferably 4,000 to 250,000, and more preferably 5,000. Above 200,000 is particularly preferable.
The resin (A) used in the present invention is substantially an epoxy group, -COOM1 group, -OPO (OM1) (OM2) group, -PO (OM1) (OM2) group [M1 and M2 are each independently hydrogen. It represents an atom or a metal ion such as sodium, potassium or lithium or an ammonium ion. ] Is preferable. The content of these functional groups is preferably 0.3 mol / kg or less, and more preferably 0.1 mol / kg or less. When these functional groups are included, developability is lowered.
Two or more modified epoxy resins (A) used in the present invention may be used in combination.
The content of the modified epoxy resin (A) used in the present invention in the image recording layer is preferably 1 to 99% by mass, more preferably 2 to 95% by mass, and more preferably 5 to 90% by mass. The following are particularly preferred:

(B) Infrared absorbent The infrared absorbent of the present invention is preferably an infrared absorbing dye. The infrared absorbing dye has a function of converting absorbed infrared light into heat and a function of being excited by infrared light to transfer electrons and / or energy to a polymerization initiator described later. The infrared absorbing dye used in the present invention is a dye having an absorption maximum at a wavelength of 760 to 1200 nm.

As the infrared absorbing dye, compounds described in paragraph numbers [0058] to [0087] of JP-A-2008-195018 can be used.
Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes. Particularly preferred examples include cyanine dyes represented by the following general formula (a).

In the general formula (a), ^{X 1} represents a hydrogen atom, a halogen ^{atom, -N (R 9) (R} 10), - X 2 -L ¹ or a group shown below. Here, R ⁹ and R ¹⁰ may be the same or different, and may have a substituent, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or an alkyl group having 1 to 8 carbon atoms. Represents a hydrogen atom, and R ⁹ and R ¹⁰ may be bonded to each other to form a ring. Of these, a phenyl group is preferred. X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or a hydrocarbon group having 1 to 12 carbon atoms including a hetero atom. . In addition, a hetero atom here shows N, S, O, a halogen atom, and Se. In the group shown below, Xa ^- has Za described later ^- is defined as for, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom .

R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the image recording layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring. Or it is particularly preferable that a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxy groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Za ⁻ represents a counter anion. However, Za ⁻ is not necessary when the cyanine dye represented by formula (a) has an anionic substituent in its structure and neutralization of charge is not necessary. Preferred Za ⁻ is a halide ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, in view of the storage stability of the image recording layer coating solution. , Hexafluorophosphate ions, and aryl sulfonate ions.

  Specific examples of the cyanine dye represented by the general formula (a) that can be suitably used in the present invention include paragraph numbers [0017] to [0019] of JP-A No. 2001-133969 and JP-A No. 2002-023360. Examples thereof include those described in paragraph Nos. [0012] to [0021] of Japanese Patent Publication No. and paragraph Nos. [0012] to [0037] of JP-A No. 2002-040638.

  Moreover, only 1 type may be used for these (B) infrared absorbers, 2 or more types may be used together, and infrared absorbers other than infrared absorbing dyes, such as a pigment, may be used together. As the pigment, compounds described in JP 2008-195018 A [0072] to [0076] are preferable.

  The content of the infrared absorber in the image recording layer in the present invention is preferably 0.1 to 10.0% by mass, more preferably 0.5 to 5.0% by mass of the total solid content of the image recording layer. .

(C) Radical polymerization initiator The (C) radical polymerization initiator used in the present invention is a compound that initiates and accelerates polymerization of a radical polymerizable compound or the like. As the radical polymerization initiator that can be used in the present invention, a known thermal polymerization initiator, a compound having a bond with a small bond dissociation energy, a photopolymerization initiator, and the like can be used.
Examples of the radical polymerization initiator in the present invention include (a) an organic halide, (b) a carbonyl compound, (c) an azo compound, (d) an organic peroxide, (e) a metallocene compound, and (f) an azide compound. (G) hexaarylbiimidazole compound, (h) organic borate compound, (i) disulfone compound, (j) oxime ester compound, (k) onium salt compound.

  (A) As the organic halide, compounds described in paragraph numbers [0022] to [0023] of JP-A-2008-195018 are preferable.

  (B) As the carbonyl compound, compounds described in paragraph [0024] of JP-A-2008-195018 are preferable.

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

  (D) As the organic peroxide, for example, compounds described in paragraph [0025] of JP-A-2008-195018 are preferable.

  As the (e) metallocene compound, for example, the compound described in paragraph [0026] of JP-A-2008-195018 is preferable.

(F) Examples of the azide compound include 2,6-bis (4-azidobenzylidene) -4-methylcyclohexanone.
(G) As the hexaarylbiimidazole compound, for example, a compound described in paragraph [0027] of JP-A-2008-195018 is preferable.

  (H) As the organic borate compound, for example, a compound described in paragraph [0028] of JP-A-2008-195018 is preferable.

  (I) Examples of the disulfone compound include compounds described in JP-A Nos. 61-166544 and 2002-328465.

  (J) As the oxime ester compound, for example, compounds described in paragraph numbers [0028] to [0030] of JP-A-2008-195018 are preferable.

  (K) Examples of the onium salt compounds 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, U.S. Pat. Nos. 339,049, 410,201, U.S. Patent Application Publication No. 2008 No. 0311520, iodonium salts described in JP-A-2-150848, JP-A-2-296514, JP-A-2008-195018, European Patent Nos. 370,693 and 390,214. 233,567, 297,443, 297,442, U.S. Pat.Nos. 4,933,377, 161,811 410,201, 339,049, 4,760,013, 4,734,444, 2,833,827, German Patent 2,904,626, 3 , 604, 580, and 3,604, 581, the sulfonium salts described in the respective specifications; 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 azinium salts described in JP-A-2008-195018.

  Of these, more preferred are onium salts, especially iodonium salts, sulfonium salts and azinium salts. Although the specific example of these compounds is shown below, it is not limited to this.

  As an example of the iodonium salt, a diphenyl iodonium salt is preferable, and a diphenyl iodonium salt substituted with an electron donating group such as an alkyl group or an alkoxyl group is particularly preferable, and an asymmetric diphenyl iodonium salt is more preferable. Specific examples include diphenyliodonium = hexafluorophosphate, 4-methoxyphenyl-4- (2-methylpropyl) phenyliodonium = hexafluorophosphate, 4- (2-methylpropyl) phenyl-p-tolyliodonium = hexa. Fluorophosphate, 4-hexyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, 4-hexyloxyphenyl-2,4-diethoxyphenyliodonium = tetrafluoroborate, 4-octyloxy Phenyl-2,4,6-trimethoxyphenyliodonium = 1-perfluorobutanesulfonate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, bis ( -t- butylphenyl) iodonium tetraphenylborate and the like.

  Examples of sulfonium salts include triphenylsulfonium = hexafluorophosphate, triphenylsulfonium = benzoylformate, bis (4-chlorophenyl) phenylsulfonium = benzoylformate, bis (4-chlorophenyl) -4-methylphenylsulfonium = Examples include tetrafluoroborate and tris (4-chlorophenyl) sulfonium = 3,5-bis (methoxycarbonyl) benzenesulfonate.

  Examples of azinium salts include 1-cyclohexylmethyloxypyridinium = hexafluorophosphate, 1-cyclohexyloxy-4-phenylpyridinium = hexafluorophosphate, 1-ethoxy-4-phenylpyridinium = hexafluorophosphate, 1-cyclohexyl (2-ethylhexyloxy) -4-phenylpyridinium = hexafluorophosphate, 4-chloro-1-cyclohexylmethyloxypyridinium = hexafluorophosphate, 1-ethoxy-4-cyanopyridinium = hexafluorophosphate, 3,4 -Dichloro-1- (2-ethylhexyloxy) pyridinium = hexafluorophosphate, 1-benzyloxy-4-phenylpyridinium = hexafluorophosphate, 1-phenethylo Ci-4-phenylpyridinium = hexafluorophosphate, 1- (2-ethylhexyloxy) -4-phenylpyridinium = p-toluenesulfonate, 1- (2-ethylhexyloxy) -4-phenylpyridinium = perfluorobutanesulfonate 1- (2-ethylhexyloxy) -4-phenylpyridinium bromide, 1- (2-ethylhexyloxy) -4-phenylpyridinium tetrafluoroborate.

  The content of the radical polymerization initiator is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, and particularly preferably 0.8 to 20% by mass with respect to the total solid content constituting the image recording layer. % Can be added. Within this range, good sensitivity and good stain resistance of the non-image area during printing can be obtained.

(D) Radical polymerizable compound The (D) radical polymerizable compound that can be used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and has at least a terminal ethylenically unsaturated bond. It is preferably selected from compounds having one, preferably two or more. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and their (co) polymers.

  Specific examples include the compounds described in JP-A-2008-195018, paragraphs [0089] to [0098]. Among them, preferred are esters of aliphatic polyhydric alcohol compounds and unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and the like). Another preferred radically polymerizable compound includes a polymerizable compound having an isocyanuric acid structure described in JP-A-2005-329708.

  Among them, tris (acryloyloxyethyl) isocyanurate, bis (acryloyloxyethyl) hydroxyethyl isocyanurate, etc. are excellent in the balance between the hydrophilicity involved in on-press developability and the polymerization ability involved in printing durability. Isocyanuric acid ethylene oxide modified acrylates are particularly preferred.

  In the present invention, the radically polymerizable compound (D) is preferably used in the range of 5 to 80% by mass, more preferably 15 to 75% by mass, based on the total solid content of the image recording layer.

(E) Polymer fine particles In the present invention, polymer fine particles can be used to improve the on-press developability. The polymer fine particles in the present invention are preferably at least one fine particle selected from hydrophobic thermoplastic polymer fine particles, thermally reactive polymer fine particles, microcapsules enclosing a hydrophobic compound, and crosslinked polymer fine particles (microgel).
In the present invention, it is preferable from the viewpoint of on-press developability that the polymer fine particles have a polyoxyalkylene structure. In particular, the oxyalkylene group is preferably an oxyethylene group, and is preferably a polyoxyethylene group having 12 to 250 repeating units of the oxyethylene group.

  Hydrophobic thermoplastic polymer fine particles refer to Research Disclosure No. 1 of January 1992. 333003, JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, JP-A-9-171250 and European Patent No. 931647, etc. It means fine particles that become hydrophobized by fusing with heat generated during the process.

  Specific examples of the hydrophobic thermoplastic polymer fine particles include ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, and acrylate having a polyoxyalkylene structure. Or a homopolymer or copolymer of monomers such as methacrylate or mixtures thereof. Among these, a homopolymer or copolymer of a monomer selected from styrene, acrylonitrile, methyl methacrylate, and an acrylate or methacrylate having a polyoxyethylene structure is preferable. The fine polymer particles can be synthesized by a known method of emulsion polymerization or suspension polymerization of the above monomers.

The heat-reactive polymer fine particles include polymer fine particles having a heat-reactive group, and these mean fine particles that form a hydrophobized region by crosslinking due to a thermal reaction and a functional group change at that time. The thermoreactive group may be any functional group that performs a reaction as long as a chemical bond is formed, but an ethylenically unsaturated group that performs a radical polymerization reaction (for example, an acryloyl group, a methacryloyl group, a vinyl group, Allyl groups, etc.), cationically polymerizable groups (eg, vinyl groups, vinyloxy groups, etc.), isocyanate groups that perform addition reactions or their block bodies, epoxy groups, vinyloxy groups, and functional groups having active hydrogen atoms that are reaction partners thereof. A group (for example, an amino group, a hydroxy group, a carboxy group, etc.), a carboxy group that performs a condensation reaction, and a hydroxy group or amino group that is a reaction partner, an acid anhydride that performs a ring-opening addition reaction, and an amino group or hydroxy that is a reaction partner A group etc. can be mentioned as a suitable thing.
Introduction of the heat-reactive functional group and the polyoxyalkylene structure into the polymer fine particles may be performed at the time of polymerization, or may be performed using a polymer reaction after the polymerization.

  As the microcapsules used in the present invention, for example, as described in JP-A Nos. 2001-277740 and 2001-277742, all or part of the constituent components of the image recording layer are encapsulated in the microcapsules. Is. The constituent components of the image recording layer can also be contained outside the microcapsules. Furthermore, it is preferable that the image recording layer containing the microcapsule includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule.

  In this invention, the aspect containing a crosslinked resin particle, ie, a microgel, may be sufficient. This microgel can contain a part of the components of the image recording layer in and / or on the surface thereof. In particular, the microgel has a reactive microgel by having (C) a polymerizable compound on the surface thereof. From the viewpoint of image formation sensitivity and printing durability, it is particularly preferable.

  The introduction of a polyoxyalkylene structure into a microcapsule or microgel is a known method such as a method of adding polyoxyalkylene monoalkyl ether to a component of interfacial polymerization using a polyfunctional isocyanate. It can be done as an application.

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

  The content of the polymer fine particles is preferably in the range of 5 to 90% by mass of the total solid content of the image recording layer.

(F) Other components The image recording layer in the invention may further contain other components as required.

(1) Low molecular weight hydrophilic compound The image recording layer in the invention may contain a low molecular weight hydrophilic compound in order to improve the on-press developability without reducing the printing durability.
As the low molecular weight hydrophilic compound, for example, as the water-soluble organic compound, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and the like glycols and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol and tris (2-hydroxyethyl) isocyanurate, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, organic sulfones such as alkylsulfonic acid, toluenesulfonic acid and benzenesulfonic acid Acids and salts thereof, organic sulfamic acids such as alkylsulfamic acid and salts thereof, organic sulfuric acids such as alkylsulfuric acid and alkylethersulfuric acid and salts thereof, phenylphosphone Organic phosphonic acids and their salts etc., tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, organic carboxylic acids and salts thereof such as amino acids, betaines, and the like.

  Among these, in the present invention, it is preferable to contain at least one selected from the group consisting of polyols, organic sulfates, organic sulfonates, and betaines.

  Specific examples of organic sulfonates include alkyl sulfonates such as sodium n-butyl sulfonate, sodium n-hexyl sulfonate, sodium 2-ethylhexyl sulfonate, sodium cyclohexyl sulfonate, and sodium n-octyl sulfonate. Sodium 5,8,11-trioxapentadecane-1-sulfonate, sodium 5,8,11-trioxaheptadecane-1-sulfonate, 13-ethyl-5,8,11-trioxaheptadecane-1; Alkyl sulfonates containing ethylene oxide chains such as sodium sulfonate, 5,8,11,14-tetraoxatetradecosane-1-sodium sulfonate; sodium benzenesulfonate, sodium p-toluenesulfonate, p-hydroxy Benzenesulfo Acid sodium, sodium p-styrenesulfonate, sodium dimethyl-5-sulfonate isophthalate, sodium 1-naphthylsulfonate, sodium 4-hydroxynaphthylsulfonate, disodium 1,5-naphthalenedisulfonate, 1,3,6 -Aryl sulfonates such as trisodium naphthalene trisulfonate. The salt may be a potassium salt or a lithium salt.

  Organic sulfates include sulfates of alkyl, alkenyl, alkynyl, aryl or heterocyclic monoethers of polyethylene oxide. The number of ethylene oxide units is preferably 1 to 4, and the salt is preferably a sodium salt, potassium salt or lithium salt.

  As the betaines, compounds having 1 to 5 carbon atoms of the hydrocarbon substituent on the nitrogen atom are preferable. Specific examples include trimethylammonium acetate, dimethylpropylammonium acetate, 3-hydroxy-4-trimethyl. Ammonioobylate, 4- (1-pyridinio) butyrate, 1-hydroxyethyl-1-imidazolioacetate, trimethylammonium methanesulfonate, dimethylpropylammonium methanesulfonate, 3-trimethylammonio-1-propanesulfonate, Examples include 3- (1-pyridinio) -1-propanesulfonate.

  The above low molecular weight hydrophilic compound has a small hydrophobic part structure and almost no surface-active action, so that dampening water penetrates into the exposed part of the image recording layer (image part) and the hydrophobicity and film strength of the image part. Ink acceptability and printing durability of the image recording layer can be maintained satisfactorily.

The amount of these low molecular weight hydrophilic compounds added to the image recording layer is preferably 0.5% by mass or more and 25% by mass or less of the total solid content of the image recording layer. More preferably, it is 1 mass% or more and 20 mass% or less, More preferably, it is 2 mass% or more and 15 mass% or less. In this range, good on-press developability and printing durability can be obtained.
These compounds may be used alone or in combination of two or more.

(2) Grease Sensitizer In the image recording layer of the present invention, a lipid sensitizer such as a phosphonium compound, a nitrogen-containing low molecular weight compound, or an ammonium group-containing polymer is used for the image recording layer in order to improve the inking property. be able to. In particular, when an inorganic layered compound is contained in the protective layer, these compounds function as a surface coating agent for the inorganic layered compound, and prevent a decrease in the inking property during printing by the inorganic layered compound.

  Suitable phosphonium compounds include phosphonium compounds described in JP-A-2006-297907 and JP-A-2007-50660. Specific examples include tetrabutylphosphonium iodide, butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide, 1,4-bis (triphenylphosphonio) butanedi (hexafluorophosphate), 1,7-bis (tri Phenylphosphonio) heptane sulfate, 1,9-bis (triphenylphosphonio) nonane = naphthalene-2,7-disulfonate, and the like.

  Examples of the nitrogen-containing low molecular weight compound include amine salts and quaternary ammonium salts. Also included are imidazolinium salts, benzoimidazolinium salts, pyridinium salts, and quinolinium salts. Of these, quaternary ammonium salts and pyridinium salts are preferable. Specific examples include tetramethylammonium = hexafluorophosphate, tetrabutylammonium = hexafluorophosphate, dodecyltrimethylammonium = p-toluenesulfonate, benzyltriethylammonium = hexafluorophosphate, benzyldimethyloctylammonium = hexafluorophosphate. Examples thereof include fert and benzyldimethyldodecyl ammonium = hexafluorophosphate.

  The ammonium group-containing polymer may be any polymer as long as it has an ammonium group in its structure, but a polymer containing 5 to 80 mol% of a (meth) acrylate having an ammonium group in the side chain as a copolymerization component is preferable. .

  The ammonium salt-containing polymer has a reduced specific viscosity (unit: cSt / g / ml) determined by the following measurement method, preferably in the range of 5 to 120, more preferably in the range of 10 to 110. The range of 15-100 is especially preferable.

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

Specific examples of the ammonium group-containing polymer are shown below.
(1) 2- (trimethylammonio) ethyl methacrylate = p-toluenesulfonate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 10/90)
(2) 2- (Trimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80)
(3) 2- (Ethyldimethylammonio) ethyl methacrylate = p-toluenesulfonate / hexyl methacrylate copolymer (molar ratio 30/70)
(4) 2- (Trimethylammonio) ethyl methacrylate = hexafluorophosphate / 2-ethylhexyl methacrylate copolymer (molar ratio 20/80)
(5) 2- (Trimethylammonio) ethyl methacrylate = methyl sulfate / hexyl methacrylate copolymer (molar ratio 40/60)
(6) 2- (butyldimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80)
(7) 2- (Butyldimethylammonio) ethyl acrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80)
(8) 2- (butyldimethylammonio) ethyl methacrylate = 13-ethyl-5,8,11-trioxa-1-heptadecanesulfonate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80 )
(9) 2- (butyldimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate / 2-hydroxy-3-methacryloyloxypropyl methacrylate copolymer (molar ratio 15/80/5 )

  The content of the sensitizer is preferably 0.01 to 30.0% by mass, more preferably 0.1 to 20.0% by mass, and 1 to 15% by mass with respect to the total solid content of the image recording layer. Is more preferable.

(3) Others Further, as other components, surfactants, colorants, print-out agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic fine particles, inorganic layered compounds, co-sensitizers or chain transfer agents, etc. Can be added. Specifically, paragraph numbers [0114] to [0159] of JP-A-2008-284817, paragraph numbers [0023] to [0027] of JP-A-2006-091479, US Patent Application Publication No. 2008/0311520. The compounds and addition amounts described in the specification [0060] are preferred.

(G) Formation of Image Recording Layer The image recording layer in the present invention may be prepared by using the necessary components described above as described in paragraphs [0142] to [0143] of JP-A-2008-195018, for example. A coating solution is prepared by dispersing or dissolving in a coating solution, which is formed by applying the coating solution on a support by a known method such as bar coater coating and drying. The image recording layer coating amount (solid content) on the support obtained after coating and drying varies depending on the application, but is generally preferably 0.3 to 3.0 g / m ² . Within this range, good sensitivity and good film characteristics of the image recording layer can be obtained.

(Undercoat layer)
In the lithographic printing plate precursor according to the invention, an undercoat layer (sometimes referred to as an intermediate layer) is preferably provided between the image recording layer and the support. The undercoat layer enhances the adhesion between the support and the image recording layer in the exposed area, and easily peels off the image recording layer from the support in the unexposed area. Contributes to improvement. In the case of infrared laser exposure, the undercoat layer functions as a heat insulating layer, thereby preventing the heat generated by the exposure from diffusing to the support and reducing the sensitivity.

Specific examples of the compound used for the undercoat layer include silane coupling agents having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679, and JP-A-2- Examples thereof include phosphorus compounds having an ethylenic double bond reactive group described in Japanese Patent No. 304441. More preferable is a polymer resin having an adsorptive group, a hydrophilic group, and a crosslinkable group that can be adsorbed on the surface of the support, as described in JP-A Nos. 2005-125749 and 2006-188038. It is done. The polymer resin is preferably a copolymer of a monomer having an adsorptive group, a monomer having a hydrophilic group, and a monomer having a crosslinkable group. More specifically, a phenolic hydroxyl group, a carboxyl _{group, -PO 3 H 2, -OPO 3} H 2, -CONHSO 2 -, - SO 2 NHSO 2 -, - having an adsorptive group such as COCH 2 COCH ₃ Examples thereof include a polymer resin that is a copolymer of a monomer, a monomer having a hydrophilic sulfo group, and a monomer having a polymerizable crosslinkable group such as a methacryl group or an allyl group. This polymer resin may have a crosslinkable group introduced by salt formation between a polar substituent of the polymer resin, a substituent having a counter charge and a compound having an ethylenically unsaturated bond, Other monomers, preferably hydrophilic monomers, may be further copolymerized.

The content of unsaturated double bonds in the polymer resin for the undercoat layer is preferably 0.1 to 10.0 mmol, and most preferably 2.0 to 5.5 mmol, per 1 g of the polymer resin.
The polymer resin for the undercoat layer preferably has a mass average molar mass of 5000 or more, more preferably 10,000 to 300,000.

  The undercoat layer of the present invention comprises, in addition to the above undercoat compound, a chelating agent, a secondary or tertiary amine, a polymerization inhibitor, an amino group, or a functional group having a polymerization inhibiting ability, in order to prevent contamination over time. Compounds having a group that interacts with the surface of an aluminum support (for example, 1,4-diazabicyclo [2,2,2] octane (DABCO), 2,3,5,6-tetrahydroxy-p-quinone, chloranil , Sulfophthalic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylenediaminediacetic acid, hydroxyethyliminodiacetic acid, and the like.

The undercoat layer is applied by a known method. The 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.}

(Support)
As the support used in the lithographic printing plate precursor according to the invention, a known support is used. Of these, an aluminum plate that has been roughened and anodized by a known method is preferred.
In addition, the above aluminum plate is optionally subjected to micropore enlargement treatment or sealing treatment of an anodized film described in JP-A Nos. 2001-253181 and 2001-322365, and US Pat. 714,066, 3,181,461, 3,280,734 and 3,902,734, or alkali metal silicates as described in U.S. Pat. Surface hydrophilization treatment with polyvinylphosphonic acid or the like as described in each specification of 3,276,868, 4,153,461 and 4,689,272 is appropriately performed and performed. be able to.
The support preferably has a center line average roughness of 0.10 to 1.2 μm.

  If necessary, the support of the present invention includes an organic polymer compound described in JP-A-5-45885 and a silicon alkoxy compound described in JP-A-5-45885 on the back surface. A backcoat layer can be provided.

(Protective layer)
In the lithographic printing plate precursor according to the invention, a protective layer (overcoat layer) is preferably provided on the image recording layer. In addition to the function of suppressing the image formation inhibition reaction by blocking oxygen, the protective layer has a function of preventing scratches in the image recording layer and preventing ablation during high-illuminance laser exposure.

  The protective layer having such characteristics is described in, for example, US Pat. No. 3,458,311 and Japanese Patent Publication No. 55-49729. As the low oxygen permeability polymer used for the protective layer, either a water-soluble polymer or a water-insoluble polymer can be appropriately selected and used. Specific examples include polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, water-soluble cellulose derivatives, poly (meth) acrylonitrile, and the like.

Further, in order to enhance the oxygen barrier property, the protective layer preferably contains an inorganic layered compound such as natural mica and synthetic mica as described in JP-A-2005-119273.
Further, the protective layer may contain known additives such as a plasticizer for imparting flexibility, a surfactant for improving coating properties, and inorganic fine particles for controlling surface slipperiness. Further, the protective layer can contain the sensitizer described in the description of the image recording layer.

The protective layer is applied by a known method. The coating amount of the protective layer, the coating amount after drying is preferably in the range of 0.01 to 10 g / ^{m 2,} more preferably in the range of 0.02 to 3 g / ^{m 2,} and most preferably 0. in the range of 02~1g / ^{m 2.}

[Lithographic printing method]
The plate making of the lithographic printing plate precursor according to the invention is preferably carried out by an on-press development method. The on-press development method includes an image exposure process for a lithographic printing plate precursor, a printing process in which an oil-based ink and an aqueous component are supplied and printed without performing any development process on the exposed lithographic printing plate precursor. And the unexposed portion of the lithographic printing plate precursor is removed during the printing process. Imagewise exposure may be performed on the printing machine after the lithographic printing plate precursor is mounted on the printing machine, or may be separately performed with a plate setter or the like. In the latter case, the exposed lithographic printing plate precursor is mounted on a printing machine without undergoing a development process. Thereafter, by using the printing machine and supplying the oil-based ink and the aqueous component and printing as it is, an on-press development process, that is, an image recording layer in an unexposed area is removed at an early stage of printing, Accordingly, the surface of the hydrophilic support is exposed to form a non-image part. As the oil-based ink and the aqueous component, ordinary lithographic printing ink and fountain solution are used.
This will be described in more detail below.

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

  The exposed lithographic printing plate precursor is mounted on a plate cylinder of a printing press. In the case of a printing press equipped with a laser exposure device, image exposure is performed after a lithographic printing plate precursor is mounted on a plate cylinder of the printing press.

  When printing is performed by supplying dampening water and printing ink to the lithographic printing plate precursor exposed imagewise, the image recording layer cured by exposure has a printing ink acceptance having an oleophilic surface in the exposed portion of the image recording layer. Forming part. On the other hand, in the unexposed area, the uncured image recording layer is removed by dissolution or dispersion by the supplied dampening water and / or printing ink, and a hydrophilic surface is exposed in that area. As a result, the fountain solution adheres to the exposed hydrophilic surface, and the printing ink is deposited on the image recording layer in the exposed area and printing is started.

Here, dampening water or printing ink may be supplied to the printing plate first, but printing is first performed in order to prevent the dampening water from being contaminated by the removed image recording layer components. It is preferable to supply ink.
In this way, the lithographic printing plate precursor according to the invention is developed on the machine on an offset printing machine and used as it is for printing a large number of sheets.

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

[Synthesis Example of Modified Epoxy Resin (A) Having Hydrophilic Functional Group]

Synthesis of modified epoxy resin (AA-1) Epoxy resin having the structure of specific example (2): 100 g (mass average molar mass (Mw): 10,000, epoxy equivalent: 0.3 mol), 2- [2- ( 2-methoxyethoxy) ethoxy] acetic acid: 89 g (0.5 mol) was dissolved in methyl ethyl ketone: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After cooling the reaction solution to room temperature, the reaction solution was slowly poured into 5 mol of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for one day and night. Then, drying was continued until the mass became constant under reduced pressure at room temperature to obtain 152 g of a modified epoxy resin (AA-1) having a hydrophilic functional group. The obtained modified epoxy resin (AA-1) had a mass average molar mass of 11,000.

Synthesis of modified epoxy resin (AA-2) Epoxy resin having the structure of specific example (4): 100 g (mass average molar mass: 15,000, epoxy equivalent: 0.55 mol), compound (a-1): 20 g ( 0.064 mol), methacrylic acid: 8.6 g (0.1 mol), p-benzoquinone: 1.6 mg are dissolved in methyl ethyl ketone: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) is added and stirred. The mixture was refluxed for 5 hours. After 5 hours, the reaction solution was cooled to room temperature, acetic acid: 30 g (0.5 mol) was added, and the mixture was refluxed for 3 hours while stirring again. After 3 hours, the reaction solution was slowly poured into 5 L of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. Add 2 L of water to the remaining viscous solid and continue stirring for 30 minutes. Then, remove the supernatant in the same manner, spread the remaining viscous solid on a petri dish, and air-dry for two days and nights. Modified epoxy resin (AA-2) having: 121 g was obtained. The obtained modified epoxy resin (AA-2) had a mass average molar mass of 17,000.

Synthesis of modified epoxy resin (AA-3) Epoxy resin having the structure of specific example (9): 100 g (mass average molar mass: 5,500, m / n = 8/2, epoxy equivalent: 0.43 mol), methacryl Acid: 43 g (0.5 mol) and p-benzoquinone: 10 mg were dissolved in methyl ethyl ketone: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After 5 hours, the reaction solution was cooled to room temperature, and then the reaction solution was slowly poured into 5 L of a vigorously stirred 1 mol / L sodium bicarbonate aqueous solution. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. The total amount of the obtained resin was redissolved in 500 g of methyl ethyl ketone, 20 g (0.033 mol) of compound (a-3) and 1 g of dibutyltin dilaurate were added, and the mixture was stirred at 50 ° C. for 6 hours. After 6 hours, the reaction solution was cooled to room temperature, and then diluted with 500 g of ethyl acetate, and the reaction solution was washed with a saturated aqueous sodium hydrogen carbonate solution: 500 mL and a saturated saline solution: 500 mL. After drying the reaction solution over magnesium sulfate, 10 mg of p-benzoquinone was added and the solvent was concentrated under reduced pressure to obtain 155 g of a modified epoxy resin (AA-3) having a hydrophilic functional group. The obtained modified epoxy resin (AA-3) had a mass average molar mass of 6,000.

Synthesis of modified epoxy resin (AA-4) Epoxy resin having the structure of specific example (1): 100 g (mass average molar mass: 2,500, epoxy equivalent: 0.34 mol), acrylic acid: 36 g (0.5 mol) , P-benzoquinone: 10 mg was dissolved in methyl ethyl ketone: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After 5 hours, the reaction solution was cooled to room temperature, butyl isocyanate: 30 g (0.3 mol) and dibutyltin dilaurate: 3 g were added, and the mixture was stirred at 50 ° C. for 6 hours. After 6 hours, the reaction solution was cooled to room temperature, and then slowly poured into 5 L of a vigorously stirred 1 mol / L aqueous sodium hydrogen carbonate solution: 5 L. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. The total amount of the resin obtained was dissolved in 500 g of acetonitrile, p-benzoquinone: 10 mg, triethylamine: 4 g (0.04 mol), compound (a-11): 3.4 g (0.02 mol) was added, and 5 at room temperature was added. Stir for hours. After 5 hours, the reaction solution was ice-cooled to 5 ° C. or lower, 1N tetrabutylammonium hydroxide: 20 mL was added over 1 hour, and the mixture was further stirred for 1 hour while being ice-cooled. After 1 hour, the solvent and triethylamine were concentrated under reduced pressure to obtain 165 g (solid content concentration: 90% by mass) of a modified epoxy resin (AA-4) having a hydrophilic functional group. The obtained modified epoxy resin (AA-4) had a mass average molar mass of 3,200.

Synthesis of modified epoxy resin (AA-5) Epoxy resin having the structure of specific example (2): 10 g (mass average molar mass: 10,000, epoxy equivalent: 0.03 mol), compound (a-23): 1 g ( 0.0025 mol), tetramethylammonium iodide: 0.1 g was added and heated at 170 ° C. for 3 hours with stirring. After cooling the reaction solution to room temperature, the reaction mixture was dissolved in acetonitrile: 50 mL, 2-ethylhexanoic acid: 1.4 g (0.01 mol) was added, and the mixture was refluxed for 5 hours with stirring. After 5 hours, acetic acid: 3 g (0.05 mol) was added while the reaction solution was heated, and the reflux was further continued for 5 hours. Excess acetic acid and solvent were removed from the reaction solution cooled to room temperature under reduced pressure to obtain 9 g of a modified epoxy resin (AA-5) having a hydrophilic functional group. The obtained modified epoxy resin (AA-5) had a mass average molar mass of 10,500.

Synthesis of Modified Epoxy Resin (AA-6) Epoxy resin having the structure of specific example (2): 100 g (mass average molar mass: 10,000, epoxy equivalent: 0.3 mol), compound (a-16): 59 g ( 0.5 mol) was dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After cooling the reaction solution to room temperature, the reaction solution was slowly poured into 5 mol of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for one day and night. Then, drying was continued until the mass became constant under reduced pressure at room temperature to obtain 143 g of a modified epoxy resin (AA-6) having a hydrophilic functional group. The obtained modified epoxy resin (AA-6) had a mass average molar mass of 10,700.

Synthesis of Modified Epoxy Resin (AA-7) Epoxy resin having the structure of specific example (2): 100 g (mass average molar mass: 10,000, epoxy equivalent: 0.3 mol), compound (a-25): 14 g ( 0.06 mol) was dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After 5 hours, acetic acid: 30 g (0.5 mol) was added while the reaction solution was heated, and the reflux was further continued for 5 hours. Excess acetic acid and solvent were removed from the reaction solution cooled to room temperature under reduced pressure to obtain 115 g of a modified epoxy resin (AA-7) having a hydrophilic functional group. The obtained modified epoxy resin (AA-7) had a mass average molar mass of 10,300.

Synthesis of Modified Epoxy Resin (AA-8) Epoxy Resin having Structure of Specific Example (2): 100 g (mass average molar mass: 10,000, epoxy equivalent: 0.3 mol), Compound (a-27): 10 g ( 0.1 mol) was dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After 5 hours, acetic acid: 30 g (0.5 mol) was added while the reaction solution was heated, and the reflux was further continued for 5 hours. After cooling to room temperature, the reaction solution was slowly poured into 5 L of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for one day and night. Thereafter, drying was continued until the mass became constant under reduced pressure at room temperature. The obtained resin was dissolved in acetonitrile, the solution was stirred and cooled to 5 ° C. or lower, and camphorsulfonic acid: 21 g (0.09 mol) was added little by little so that the liquid temperature did not exceed 5 ° C. After the total amount was added, stirring was continued at 5 ° C. or lower for 30 minutes. The solvent was removed from the reaction solution under reduced pressure to obtain 135 g of a modified epoxy resin having a hydrophilic functional group (AA-8). The obtained modified epoxy resin (AA-8) had a mass average molar mass of 11,100.

Synthesis of Modified Epoxy Resin (AA-9) Epoxy Resin having Structure of Specific Example (2): 100 g (mass average molar mass: 10,000, epoxy equivalent: 0.3 mol), compound (a-4): 15 g ( 0.032 mol) was dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After 5 hours, the reaction solution was cooled to room temperature, acetic acid: 30 g (0.5 mol) was added, and the mixture was refluxed for 3 hours while stirring again. After 3 hours, the reaction solution was slowly poured into 5 L of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. Water: 2 L was added to the remaining viscous solid, and stirring was continued for 30 minutes. Then, the supernatant liquid was removed in the same manner, the remaining viscous solid was spread on a petri dish and air-dried for one day and night. And dried until the mass did not change. Thus, 114 g of a modified epoxy resin (AA-9) having a hydrophilic functional group was obtained. The obtained modified epoxy resin (AA-9) had a mass average molar mass of 10,900.

Synthesis of Modified Epoxy Resin (AA-10) Epoxy Resin having Structure of Specific Example (2): 100 g (mass average molar mass: 10,000, epoxy equivalent: 0.3 mol), Compound (a-2): 10 g ( 0.005 mol), tetraethylammonium bromide: 7.2 g (0.034 mol) was dissolved in N-methylpyrrolidone: 500 g and heated at 150 ° C. for 5 hours with stirring. After 5 hours, the reaction solution was cooled to room temperature, acetic acid: 30 g (0.5 mol) was added, and the mixture was heated at 150 ° C. for 3 hours while stirring again. After 3 hours, the reaction solution was slowly poured into 5 L of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. Water: 2 L was added to the remaining viscous solid, and stirring was continued for 30 minutes. Then, the supernatant liquid was removed in the same manner, the remaining viscous solid was spread on a petri dish and air-dried for one day and night. And dried until the mass did not change. Thus, 111 g of a modified epoxy resin (AA-10) having a hydrophilic functional group was obtained. The obtained modified epoxy resin (AA-10) had a mass average molar mass of 13,100.

Synthesis of modified epoxy resin (AA-11) Epoxy resin having the structure of specific example (2): 100 g (mass average molar mass: 10,000, epoxy equivalent: 0.3 mol), acrylic acid: 36 g (0.5 mol) Tetraethylammonium bromide: 7.2 g (0.034 mol) and p-benzoquinone: 10 mg were dissolved in 500 g of methyl ethyl ketone and refluxed for 5 hours with stirring. After 5 hours, the reaction solution was cooled to room temperature, and then the reaction solution was slowly poured into 5 L of a vigorously stirred 1 mol / L sodium bicarbonate aqueous solution. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. The obtained resin was dissolved in acetonitrile: 500 g, p-benzoquinone: 10 mg, triethylamine: 3 g were added, and the mixture was stirred at room temperature. Compound (a-8): 20 g (0.02 mol) was added to this mixed solution over 1 hour, and the mixture was stirred at 75 ° C. for 3 hours after completion of the addition. After 3 hours, acetonitrile and triethylamine were distilled off from the reaction solution under reduced pressure, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. Thus, 132 g of a modified epoxy resin (AA-11) having a hydrophilic functional group was obtained. The obtained modified epoxy resin (AA-11) had a mass average molar mass of 12,000.

Synthesis of modified epoxy resin (AA-12) Epoxy resin having the structure of specific example (2): 100 g (mass average molar mass: 10,000, epoxy equivalent: 0.3 mol), acrylic acid: 36 g (0.5 mol) Tetraethylammonium bromide: 7.2 g (0.034 mol) and p-benzoquinone: 10 mg were dissolved in 500 g of methyl ethyl ketone and refluxed for 5 hours with stirring. After 5 hours, the reaction solution was cooled to room temperature, and then the reaction solution was slowly poured into 5 L of a vigorously stirred 1 mol / L sodium bicarbonate aqueous solution. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. The obtained resin was dissolved in acetonitrile: 500 g, p-benzoquinone: 10 mg, triethylamine: 3 g were added, and the mixture was stirred at room temperature. Compound (a-9): 20 g (0.02 mol) was added to this mixed solution over 1 hour, and the mixture was stirred at 75 ° C. for 3 hours after completion of the addition. After 3 hours, acetonitrile and triethylamine were distilled off from the reaction solution under reduced pressure, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. Thus, 132 g of modified epoxy resin (AA-12) having a hydrophilic functional group was obtained. The obtained modified epoxy resin (AA-12) had a mass average molar mass of 12,100.

Synthesis of modified epoxy resin (AA-13) Epoxy resin having the structure of specific example (15): 100 g (mass average molar mass: 1,800, epoxy equivalent: 0.39 mol), acrylic acid: 36 g (0.5 mol) , P-benzoquinone: 10 mg was dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After cooling the reaction solution to room temperature, the reaction solution was slowly poured into 5 mol of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. The dried resin was dissolved in acetonitrile: 500 g, p-benzoquinone: 10 mg, compound (a-21): 43 g (0.2 mol) and Neostan U-600 (manufactured by Nitto Kasei Co., Ltd.): 1 g were added, and 50 ° C. And stirred for 6 hours. Then, acetonitrile was depressurizingly distilled and the modified epoxy resin (AA-13) which has a hydrophilic functional group: 150g (solid content concentration: 91 mass%) was obtained. The obtained modified epoxy resin (AA-13) had a mass average molar mass of 2,000.

Synthesis of modified epoxy resin (AA-14) Epoxy resin having the structure of specific example (9): 100 g (mass average molar mass: 3,500, m / n = 6/4, epoxy equivalent: 0.55 mol), itacon Acid monoamide: 65 g (0.5 mol) and p-benzoquinone: 10 mg were dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After cooling the reaction solution to room temperature, the reaction solution was slowly poured into 5 mol of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. Thus, 123 g of a modified epoxy resin (AA-14) having a hydrophilic functional group was obtained. The obtained modified epoxy resin (AA-14) had a mass average molar mass of 3,900.

Synthesis of modified epoxy resin (AA-15) Epoxy resin having the structure of specific example (6): 100 g (mass average molar mass: 4,000, m / n = 8/2, epoxy equivalent: 0.5 mol), the following Compound: 51 g (0.25 mol) and p-benzoquinone: 10 mg were dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. The reaction mixture was cooled to room temperature, acetic acid: 30 g (0.5 mol) was added, and the mixture was further refluxed for 3 hours. The reaction solution cooled to room temperature was slowly poured into 5 L of a vigorously stirred 1 mol / L aqueous sodium bicarbonate solution: 5 L. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for 2 days and nights. 141 g of a modified epoxy resin (AA-15) having a hydrophilic functional group was obtained. The obtained modified epoxy resin (AA-15) had a mass average molar mass of 4,500.

Synthesis of modified epoxy resin (AA-16) jER1256 (Japan Epoxy Resin Co., Ltd. epoxy resin) 100 g (mass average molar mass: 50,000, epoxy equivalent: 0.013 mol), compound (a-6): 51 g ( 0.05 mol) was dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. The reaction solution was cooled to room temperature and then slowly poured into 5 L of a vigorously stirred 1 mol / L aqueous sodium bicarbonate solution: 5 L. After stirring for 30 minutes, stirring was stopped and the viscous solid precipitated was settled to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining viscous solid and stirring for 30 minutes, the supernatant was removed in the same manner, and the remaining viscous solid was spread on a petri dish and air-dried for one day and night. Then, it dried until the mass did not change under reduced pressure at room temperature to obtain 111 g of a modified epoxy resin (AA-16) having a hydrophilic functional group. The obtained modified epoxy resin (AA-16) had a mass average molar mass of 51,000.

Synthesis of Modified Epoxy Resin (AA-17) EPICLON EXA-4850-150 (Epoxy Resin, Dainippon Ink & Chemicals, Inc.) 100 g (mass average molar mass: 900, epoxy equivalent: 0.22 mol), adipic acid: 2 g (0.015 mol) was dissolved in acetonitrile: 500 g, tetraethylammonium bromide: 7.2 g (0.034 mol) was added, and the mixture was refluxed for 5 hours with stirring. After cooling the reaction solution to room temperature, methacrylic acid: 43 g (0.5 mol) and p-benzoquinone: 10 mg were added, and the mixture was further refluxed for 5 hours with stirring. The reaction solution was poured slowly into 5 L of 1 mol / L aqueous sodium hydrogen carbonate solution vigorously stirred. After stirring for 30 minutes, stirring was stopped and the precipitated compound was allowed to settle to the bottom of the container, and the supernatant was carefully removed. After adding 2 L of water to the remaining compound and stirring for 30 minutes, the supernatant was removed in the same manner, the remaining compound was spread on a petri dish and air-dried for 2 days and nights. The obtained resin was dissolved in acetonitrile: 500 g, p-benzoquinone: 10 mg, compound (a-21): 22 g (0.1 mol), Neostan U-600 (manufactured by Nitto Kasei Co., Ltd.): 1 g was added, The mixture was heated and stirred at 50 ° C. for 6 hours. Thereafter, acetonitrile was distilled off under reduced pressure, and then dissolved in 1 L of ethyl acetate. The obtained ethyl acetate solution was washed with saturated aqueous sodium hydrogen carbonate solution: 500 mL and saturated brine: 500 mL, and then dried over magnesium sulfate. The ethyl acetate solution was filtered and then concentrated under reduced pressure to obtain 147 g (solid content concentration: 88% by mass) of a modified epoxy resin (AA-17) having a hydrophilic functional group. The obtained modified epoxy resin (AA-17) had a mass average molar mass of 3,100.

Synthesis of Modified Epoxy Resin (AA-18) A modified epoxy resin (AA-18) was synthesized in the same manner as the modified epoxy resin (AA-1) except that the mass average molar mass of the epoxy resin was changed to 5000. The molecular weight of the obtained modified epoxy resin (AA-18) was 5100.

Synthesis of Modified Epoxy Resin (AA-19) A modified epoxy resin (AA-19) was synthesized in the same manner as the modified epoxy resin (AA-1) except that the mass average molar mass of the epoxy resin was changed to 2500. The molecular weight of the obtained modified epoxy resin (AA-19) was 2600.

[Examples 1 to 6 and Comparative Example 1]
(1) Production of lithographic printing plate support (1) In order to remove rolling oil on the surface of an aluminum plate (material JIS A 1050) having a thickness of 0.3 mm, a 10 mass% sodium aluminate aqueous solution was used at 50 ° C. for 30 minutes. After degreasing for 2 seconds, the aluminum surface was grained using ^three bundled nylon brushes having a bristle diameter of 0.3 mm and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm. Wash well 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. At this time, the etching amount of the grained surface was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power source waveform is electrochemical roughening treatment using a trapezoidal rectangular wave alternating current with a time ratio TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave alternating current. Went. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. The amount of electricity in nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode. Then, water washing by spraying was performed.

Subsequently, nitric acid electrolysis was performed with an aqueous solution of 0.5% by mass of hydrochloric acid (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. under the condition of an electric quantity of 50 C / dm ² when the aluminum plate was the anode. In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying.
Next, the plate was provided with a direct current anodic oxide film having a current density of 15 A / dm ² and a current density of 15 g / m ² using 15% by mass sulfuric acid (containing 0.5% by mass of aluminum ions) as an electrolytic solution, followed by washing with water. It dried and produced the support body (1).
Thereafter, in order to ensure the hydrophilicity of the non-image area, the support (1) was subjected to a silicate treatment at 60 ° C. for 10 seconds using an aqueous 2.5 mass% No. 3 sodium silicate solution, and then washed with water for support. Body (2) was obtained. The adhesion amount of Si was 10 mg / m ² . 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) Formation of undercoat layer Next, the following undercoat layer coating solution (1) is applied onto the support (2) so that the dry coating amount is 20 mg / m ² , and used in the following experiments. A support having a layer was prepared.

<Coating liquid for undercoat layer (1)>
-Undercoat layer compound (1) having the following structure: 0.18 g
・ Hydroxyethyliminodiacetic acid 0.10g
・ Methanol 55.24g
・ Water 6.15g

(3) Formation of image recording layer The image recording layer coating solution (1) having the following composition was bar-coated on the undercoat layer formed as described above, and then oven-dried at 100 ° C for 60 seconds to obtain a dry coating amount. An image recording layer of 1.0 g / m ² was formed.
The image recording layer coating solution (1) was obtained by mixing and stirring the following photosensitive solution (1) and microgel solution (1) immediately before coating.

<Photosensitive solution (1)>
・ Modified epoxy resin (A) [described in Table 1] 0.432 g
Infrared absorbing dye (1) [the following structure] 0.030 g
-Radical polymerization initiator (1) [the following structure] 0.162 g
・ Low molecular weight hydrophilic compound (1) [the following structure] 0.050 g
・ Sensitizer Benzyl-dimethyl-octylammonium ・ PF ₆ salt 0.018g
-Sensitizing agent Ammonium group-containing polymer [the following structure, reduced specific viscosity 44 cSt / g / ml] 0.035 g
・ Fluorosurfactant (1) [The following structure] 0.008g
・ 2-butanone 1.091g
・ 1-methoxy-2-propanol 8.609g

<Microgel solution (1)>
・ Microgel (1) 2.640 g
・ Distilled water 2.425g

  The structures of the infrared absorbing dye (1), the radical polymerization initiator (1), the low molecular weight hydrophilic compound (1), the ammonium group-containing polymer, and the fluorosurfactant (1) are as shown below. is there.

-Synthesis of microgel (1)-
As an oil phase component, trimethylolpropane and xylene diisocyanate adduct (Mitsui Chemical Polyurethane Co., Ltd., Takenate D-110N) 10 g, pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., SR444) 3.15 g, And 0.1 g of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4 mass% aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12,000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 50 ° C. for 3 hours. The microgel solution thus obtained was diluted with distilled water to a solid content concentration of 15% by mass, and this was designated as the microgel (1). When the average particle size of the microgel was measured by a light scattering method, the average particle size was 0.2 μm.

(4) Formation of protective layer After the bar coating of the protective layer coating solution (1) having the following composition was further applied on the image recording layer, it was oven-dried at 120 ° C. for 60 seconds, and the dry coating amount was 0.15 g / m ² A lithographic printing plate precursor for Examples 1 to 6 and Comparative Example 1 was obtained.

<Coating liquid for protective layer (1)>
・ Inorganic layered compound dispersion (1) 1.5 g
-Polyvinyl alcohol (Nippon Synthetic Chemical Industry Co., Ltd. CKS50, sulfonic acid modification,
Saponification degree 99 mol% or more, polymerization degree 300) 6% by mass aqueous solution 0.55 g
・ Polyvinyl alcohol (PVA-405 manufactured by Kuraray Co., Ltd.)
Degree of saponification 81.5 mol%, degree of polymerization 500) 6% by weight aqueous solution 0.03 g
・ Nippon Emulsion Co., Ltd. surfactant (Emalex 710) 1% by weight aqueous solution 0.86g
・ Ion-exchanged water 6.0g

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

4). Evaluation of lithographic printing plate precursor (1) On-press developability The obtained lithographic printing plate precursor was subjected to an external drum rotation speed of 1000 rpm and a laser output of 70% on a Luxel PLANETTER T-6000III manufactured by FUJIFILM Corporation equipped with an infrared semiconductor laser. The exposure was performed under the condition of a resolution of 2400 dpi. The exposure image included a solid image and a 50% halftone dot chart of a 20 μm dot FM screen.
The obtained exposed original plate was attached to a plate cylinder of a printing machine LITHRONE 26 manufactured by Komori Corporation without developing. Equality-2 (manufactured by FUJIFILM Corporation) / tap water = 2/98 (volume ratio) dampening water and Values-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.) After dampening water and ink were supplied by the standard automatic printing start method of LITHRONE 26 and developed on the machine, 100 sheets were printed on Tokuhishi Art (76.5 kg) paper at a printing speed of 10,000 sheets per hour.
The number of print sheets required until the on-press development on the printing press of the unexposed portion of the image recording layer was completed and the ink was not transferred to the non-image portion was measured as on-press developability. The results are shown in Table 1.

(2) Printing durability After the above-described evaluation of on-press developability, the printing was further continued. As the number of printed sheets was increased, the image recording layer was gradually worn out, so that the ink density on the printed material decreased. Printing durability was evaluated using the number of printed copies when the value measured by the Gretag densitometer for the 50% halftone dot area ratio of the FM screen in the printed material was 5% lower than the measured value for the 100th printed sheet. . The results are shown in Table 1.

Resin C-1 for Comparative Example 1
Unsaturated group and carboxyl group-containing epoxy resin (acid value 50 KOH · mg / g, mass average molar mass 5,000, “PR-300” manufactured by Showa Polymer Co., Ltd.)

  As is clear from Table 1, when the resin of the present invention is used, it is excellent in on-press developability and printing durability as compared with conventionally known epoxy resins.

[Examples 7 to 15 and Comparative Example 2]
1. Preparation of lithographic printing plate precursor The following image recording layer coating solution (2) was bar coated on the above support having an undercoat layer, followed by oven drying at 70 ° C. for 60 seconds, and a dry coating amount of 0.6 g / m. ² image recording layers were prepared, and lithographic printing plate precursors for Examples 7 to 15 and Comparative Example 2 were obtained.

<Image recording layer coating solution (2)>
-Polymer fine particle aqueous dispersion (1) 20.0 g
・ Infrared absorbing dye (2) [the following structure] 0.2g
・ Radical polymerization initiator Irgacure 250
(Ciba Specialty Chemicals) 0.5g
-Radical polymerizable compound SR-399 (Sartomer) 1.50 g
・ Mercapto-3-triazole 0.2g
・ Byk336 (byk chimie) 0.4g
・ KlucelM (Hercules) 4.8g
-0.25 g of modified epoxy resin (A) listed in Table 2
・ N-propanol 55.0g
・ 2-butanone 17.0g

In addition, the compounds described by trade names in the above composition are as follows.
Irgacure 250: (4-methoxyphenyl) [4- (2-methylpropyl) phenyl] iodonium = hexafluorophosphate (75% by mass propylene carbonate solution)
SR-399: dipentaerythritol pentaacrylate
Byk 336: modified dimethylpolysiloxane copolymer (25% by mass xylene / methoxypropyl acetate solution)
・ Klucel M: Hydroxypropyl cellulose (2% by mass aqueous solution)
ELVACITE 4026: Hyperbranched polymethyl methacrylate (10% by mass 2-butanone solution)

(Production of polymer fine particle aqueous dispersion (1))
A 1000 ml four-necked flask was equipped with a stirrer, thermometer, dropping funnel, nitrogen inlet tube, reflux condenser, and nitrogen gas was introduced to perform deoxygenation, while polyethylene glycol methyl ether methacrylate (average of PEGMA ethylene glycol) The repeating unit was 50) 10 g, distilled water 200 g and n-propanol 200 g were added and heated until the internal temperature reached 70 ° C. Next, a premixed mixture of 10 g of styrene (St), 80 g of acrylonitrile (AN) and 0.8 g of 2,2′-azobisisobutyronitrile was added dropwise over 1 hour. After completion of the dropwise addition, the reaction was continued for 5 hours, and then 0.4 g of 2,2′-azobisisobutyronitrile was added to raise the internal temperature to 80 ° C. Subsequently, 0.5 g of 2,2′-azobisisobutyronitrile was added over 6 hours. Polymerization progressed 98% or more at the stage of reaction for a total of 20 hours, and a polymer fine particle aqueous dispersion (1) having a mass ratio of PEGMA / St / AN = 10/10/80 was obtained. The particle size distribution of the polymer fine particles had a maximum value at a particle size of 150 nm.

  Here, the particle size distribution is obtained by taking an electron micrograph of polymer fine particles, measuring a total of 5000 fine particle sizes on the photograph, and a logarithmic scale between 0 and the maximum value of the obtained particle size measurement values. And the frequency of appearance of each particle size was plotted and obtained. For non-spherical particles, the particle size of spherical particles having the same particle area as that on the photograph was used as the particle size.

2. Evaluation of lithographic printing plate precursor The lithographic printing plate precursor obtained as described above was evaluated in the same manner as in Example 1 for (1) on-press developability and (2) printing durability. Moreover, (3) sensitivity was evaluated by the method shown below. The results are shown in Table 2.

(3) Sensitivity For each of the obtained lithographic printing plate precursors, a laser output of 10% was obtained under the conditions of an external drum rotating speed of 1000 rpm and a resolution of 2400 dpi using a Luxel PLANETSETTER T-6000III equipped with an infrared semiconductor laser. Ten exposed plates were produced by changing in 10% increments up to -100%. The exposure image included a solid image and a 50% halftone dot chart of a 20 μm dot FM screen.
100 sheets of the obtained exposed original plate were printed in the same manner as described above. The laser output with a 50% halftone dot image remaining after printing 100 sheets was evaluated as sensitivity. Therefore, the lower the output, the higher the sensitivity.

  As is apparent from Table 2, when the resin of the present invention is used, unexpectedly high sensitivity, on-press developability and printing durability can be obtained as compared with conventional resins.

[Examples 16 to 19 and Comparative Example 3]
1. Preparation of lithographic printing plate precursor An image recording layer coating solution (3) having the following composition was bar coated on the undercoat layer formed as described above, and then oven-dried at 100 ° C. for 60 seconds. An image recording layer of 0 g / m ² was formed. The image recording layer coating solution (3) was obtained by mixing and stirring the following photosensitive solution (3) and the microgel solution (1) immediately before coating.

<Photosensitive solution (3)>
・ Modified epoxy resin (A) listed in Table 3 0.240 g
Infrared absorbing dye (1) [above structure] 0.030 g
・ Radical polymerization initiator (1) [above structure] 0.162 g
-Radical polymerizable compound Tris (acryloyloxyethyl) isocyanurate (NK ester A-9300, manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.192 g
・ Low molecular weight hydrophilic compound Tris (2-hydroxyethyl) isocyanurate 0.062g
・ Low molecular weight hydrophilic compound (1) [above structure] 0.050 g
-Sensitizing agent Phosphonium compound (1) [the following structure] 0.055 g
・ Sensitizer Benzyl-dimethyl-octylammonium ・ PF ₆ salt 0.018g
-Sensitizer Ammonium group-containing polymer [The above structure, reduced specific viscosity 44 cSt / g / ml] 0.035 g
・ Fluorine-based surfactant (1) [above structure] 0.008 g
・ 2-butanone 1.091g
・ 1-methoxy-2-propanol 8.609g

On the image recording layer, the above protective layer coating solution (1) was further bar coated and then oven dried at 120 ° C. for 60 seconds to form a protective coating layer having a dry coating amount of 0.15 g / m ^2. Lithographic printing plate precursors for Examples 16 to 19 and Comparative Example 3 were obtained.

2. Evaluation of lithographic printing plate precursor The obtained lithographic printing plate precursor was evaluated for on-press developability, printing durability and sensitivity in the same manner as in Example 7. The results are shown in Table 3.

  As is apparent from Table 3, the printing plate of the present invention is excellent in on-press developability, printing durability and sensitivity.

[Examples 20 to 21 and Comparative Example 4]
<Preparation and evaluation of lithographic printing plate precursor>
On the support having the undercoat layer described in Example 1, the image recording layer coating solution (4) described below was applied to form an image recording layer having a dry coating amount of 2 g / m ² .

<Image recording layer coating solution (4)>
Reaction product of DESMODUR (registered trademark) N100, hydroxyethyl acrylate and pentaerythritol triacrylate * 1 3.74 parts by mass Modified epoxy resin (A) described in Table 4 3.53 parts by mass Sartomer 355 * 2 0.78 parts by mass Part 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl)
2-triazine 0.42 parts by mass Anilino-N, N-2 acetic acid 0.23 parts by mass Infrared absorbing dye (3) * 3 0.09 parts by mass Byk 307 * 4 0.02 parts by mass n-propanol 72.95 Parts by weight water 18.24 parts by weight

* 1 DESMODUR® 100: 479 g, dibutyltin dilaurate catalyst, stabilizer 2,6-di-tertbutyl-4-methylphenol is dissolved in methyl ethyl ketone at 40 ° C .; final concentration of non-volatile components is about 30 The amount of methyl ethyl ketone was selected so as to be mass%. Next, 174 g of hydroxyethyl acrylate and 447 g of pentaerythritol triacrylate were added so that the temperature did not exceed 42 ° C. After 2 hours of stirring, the temperature was raised to 60 ° C. and maintained for another 2 hours. The reaction was monitored by infrared spectroscopy and the isocyanate still present at the end was quenched with an appropriate amount of methanol.
This was slowly added to 30 liters of stirred water, and the precipitated components were taken out and dried. 1080 g of precipitate was obtained.
* 2 Sartomer 355 is based on Sartomer Co. , Inc. Is a polyfunctional acrylic monomer available from
* 3 Infrared absorbing dye (3) is 2- [2- [2-phenylthio-3-[(1,3-dihydro-1,3,3-trimethyl-2H-indole-2-ylidene) ethylidene] -1 -Cyclohexen-1-yl] ethenyl] -1,3,3-trimethyl-3H-indolium salt compound.
* 4 Byk 307 is a modified polysiloxane available from Byk Chemie.

On the obtained image recording layer, a protective layer coating solution prepared by dissolving polyvinyl alcohol (5.26 parts) and polyvinyl imidazole (0.93 parts) in isopropanol (3.94 parts) and water (89.87 parts). The lithographic printing plate precursor having a protective layer having a dry coating amount of 2 g / m ² was obtained by coating.

The on-press developability and printing durability were evaluated in the same manner as in Example 1 except that the lithographic printing plate precursor thus obtained was subjected to image formation at 250 mJ / cm ² using a Creo Trendsetter 3244x. The results are shown in Table 4.

  Resin C-3 (graft copolymer 1) of Comparative Example 4 was synthesized as follows.

(1) Synthesis of Macromer 1

  Toluene (266 g) was placed in a 500 mL flask followed by addition of poly (ethylene glycol monomethyl ether) (80 g) (Mn 2000) and methacryloyl chloride (4.2 g) in a nitrogen atmosphere. Thereafter, triethylamine (4.52 g) was added over 20 minutes while maintaining the reaction temperature at 30 ° C. After an additional 2 hours, the temperature of the reaction mixture was raised to 50 ° C. and kept at that temperature for an additional 2 hours. The reaction mixture was then cooled to room temperature and filtered to remove the theoretical amount of triethylamine hydrochloride obtained. Petroleum ether was added to the filtrate to precipitate Macromer 1, which was collected by filtration and dried in a room temperature vacuum oven. This reaction is shown in the above scheme. The average value of n is preferably about 45.

(2) Synthesis of Graft Copolymer 1 Macromer 1 (7.5 g), water (48 g), and 1-propanol (192 g) were placed in a 500 mL flask and heated to 80 ° C. Styrene (66.9 g) and azobisisobutyronitrile (0.48 g) (Vazo-64, from DuPont de Nemours Co) were mixed in a separate beaker and a portion of this solution (12 g) was mixed into the macromer solution. Upon addition, it became cloudy within about 10 minutes. The remaining solution was then added over 30 minutes. After a further 3 hours, the conversion to graft copolymer 1 was about 97% by weight based on the measurement of% non-volatile content. The weight ratio of styrene: macromer 1 was about 90:10 in graft copolymer 1.

Claims (17)

A lithographic printing plate precursor having an image recording layer containing the following (A) to (C) on a support and capable of being developed with dampening water and ink on a printing press.
(A) Modified epoxy resin having at least one hydrophilic functional group selected from polyalkylene oxide group, sulfonic acid group, sulfonic acid group, amide group, ammonium group and amino group (B) Infrared absorber (C) radical Polymerization initiator The lithographic printing plate precursor as claimed in claim 1, wherein the modified epoxy resin having a hydrophilic functional group has an ethylenically unsaturated group. The modified epoxy resin is a modified epoxy resin (A-1) obtained by reacting an epoxy resin with a compound having a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin and a hydrophilic functional group. The lithographic printing plate precursor as claimed in claim 1 or 2 , wherein: The modified epoxy resin is obtained by reacting (1) an epoxy resin with a modified epoxy resin obtained by reacting a compound having a functional group capable of reacting with an epoxy group or a substituent in the epoxy resin (2
) According to claim 1 or 2, characterized in that a compound having a modified epoxy resin of the reactable with substituent functional group and a hydrophilic functional group is a modified epoxy resin obtained by reacting (A-2) Lithographic printing plate precursor. The modified epoxy resin obtained by reacting the modified epoxy resin (A-1) with a compound having a functional group capable of reacting with an epoxy group or a substituent in the resin (A-1). The lithographic printing plate precursor as claimed in claim 3 , which is (A-3). The functional group capable of reacting with an epoxy group or a substituent in the epoxy resin is a group selected from a carboxy group, an amino group, a hydroxy group, a mercapto group, an isocyanate group, a 1,3-diketo group, and an acid anhydride group. The lithographic printing plate precursor as claimed in any one of claims 3 to 5 , wherein the lithographic printing plate precursor is present. The functional group capable of reacting with the epoxy group or substituent in the modified epoxy resin (A-1) is a carboxy group, an amino group, a hydroxy group, a mercapto group, an isocyanate group, a 1,3-diketo group, and an acid anhydride group. The lithographic printing plate precursor as claimed in claim 5 , wherein the lithographic printing plate precursor is a group selected from: The lithographic printing plate precursor as claimed in any one of claims 1 to 7 , wherein the modified epoxy resin is a resin having a mass average molar mass (Mw) of 3,000 to 300,000. The lithographic printing plate precursor as claimed in any one of claims 1 to 8 , wherein the image recording layer further comprises (D) a radical polymerizable compound. The image recording layer further comprises (E) polymer fine particles.
The lithographic printing plate precursor as described in any one of 9 above. The polymer particles, the lithographic printing plate precursor according to claim 1 0, characterized in that the microcapsules encapsulating a compound having one or more ethylenically unsaturated groups. The polymer particles, the lithographic printing plate precursor according to claim 1 0, characterized in that the fine particles of a polymer containing acrylonitrile as a monomer unit. The lithographic printing plate precursor as claimed in any one of claims 1 to 1 2, characterized by further comprising a protective layer on the image recording layer. The protective layer The lithographic printing plate precursor as claimed in claims 1 to 3, characterized by containing a hydrophilic resin. The lithographic printing plate precursor as claimed in claim 1 3 wherein the protective layer, characterized in that it contains the inorganic stratiform compound. A lithographic printing method, comprising: exposing the lithographic printing plate precursor according to any one of claims 1 to 15 on an image-like basis; A lithographic printing method comprising printing the lithographic printing plate precursor according to any one of claims 1 to 15 as it is after being placed in a printing machine and exposed imagewise.