JPWO2008156073A1 - Dampening solution composition for lithographic printing and image forming method - Google Patents

Abstract

The present invention has good on-press developability, and also has good on-press developability for a lithographic printing plate material after high-temperature storage, and it is difficult for stains on unexposed areas of printed matter to occur. Providing fountain solution for lithographic printing suitable for top development CTP and image forming method, and effective even with fountain solution containing no organic solvent such as isopropanol, and stable with little change due to evaporation of organic solvent The present invention provides a fountain solution for lithographic printing suitable for on-press development CTP and an image forming method, which has good on-press developability and can avoid VOC countermeasures and flammability problems. This means is characterized by a fountain solution for lithographic printing containing a water-soluble phosphobetaine compound.

Description

  The present invention relates to a fountain solution composition for lithographic printing and an image forming method for printing using the fountain solution composition for lithographic printing, and in particular, image formation is possible by a computer-to-plate (CTP) method. The present invention relates to a fountain solution for lithographic printing used for a lithographic printing plate material, and an image forming method for printing using the fountain solution for lithographic printing.

  In recent years, so-called processless CTP (including development on a printing press) that does not require special development processing has been developed. Processless CTP is attracting a great deal of attention because it can be applied to a direct imaging (DI) printing apparatus in which an image is directly recorded on a printing apparatus and printing is performed as it is.

  One form of processless CTP is ablation type CTP. For example, those described in JP-A-8-507727, JP-A-6-186750, JP-A-6-199064, JP-A-7-314934, JP-A-10-58636, and JP-A-10-244773.

  In these, for example, a hydrophilic layer and a lipophilic layer are laminated on a base material with either layer as a surface layer. If the surface layer is a hydrophilic layer and the lower layer is a lipophilic layer containing a photothermal conversion material, it is exposed imagewise, and the explosive heat generation of the lipophilic layer causes the hydrophilic layer to be ablated and removed imagewise. An image portion can be formed by exposing the oily layer. However, since the ablated material scatters from the plate surface during exposure, the exposure apparatus needs to be provided with a mechanism for sucking and removing the ablated material, and the versatility of the exposure apparatus is lacking. In addition, since ablation requires a large amount of energy, the sensitivity is generally low, that is, the productivity is poor when the same exposure apparatus is used.

  On the other hand, development of a printing plate material that can form an image without causing ablation and does not require a development process or a wiping process using a special developer is also underway. For example, a processless CTP (hereinafter referred to as on-machine development CTP) capable of dampening water development using thermoplastic fine particles and a water-soluble binder in an image forming layer is disclosed (see Patent Document 1).

  Since such on-machine development CTP does not require any special mechanism added to the exposure apparatus, exposure can be performed with the same exposure apparatus as the exposure apparatus for wet type thermal CTP, and a relatively high sensitivity design can be achieved. Therefore, sufficient exposure productivity can be obtained.

  The general configuration of the on-press development CTP is such that an on-press developable image forming layer is provided on a hydrophilic surface substrate. The on-press developable image forming layer contains thermoplastic hydrophobic resin fine particles, heat-sensitive hydrophobizing precursors such as microcapsules enclosing a hydrophobic compound, and on-press development accelerators such as water-soluble resins. It is.

  The above-mentioned heat-sensitive hydrophobized precursor is fixed on a hydrophilic surface base material by fusing by the heat generated by infrared laser exposure, or by crosslinking or polymerizing the image forming layer itself, and the printing machine The effect of obtaining an image intensity that is not removed even by contact with the water roller and the ink roller is exhibited.

  However, such on-machine development methods have problems such as stains on the unexposed areas of printed matter because the developability of the hydrophilic layer such as grain is insufficient compared to conventional development processing methods. .

Further, on-press development CTP using such a heat-sensitive hydrophobized precursor is generally inferior in thermal storage stability, and stains on the unexposed portion of the printed matter due to deterioration of on-press developability after high temperature storage, etc. It was a big problem.
JP-A-9-123387

  The present invention has been made in view of the above problems, and an object of the present invention is to have good on-machine developability and good on-machine developability for a lithographic printing plate material after high-temperature storage. An object of the present invention is to provide a fountain solution for lithographic printing suitable for on-press development CTP and an image forming method.

  It is also effective in dampening water that does not contain an organic solvent such as isopropanol, is stable with little change due to evaporation of the organic solvent, and can prevent VOC (volatile organic compound) countermeasures and flammability problems. An object of the present invention is to provide a fountain solution for lithographic printing having on-press developability and suitable for on-press development CTP, and an image forming method.

  The above object of the present invention can be achieved by the following constitution.

  1. A fountain solution composition for lithographic printing comprising a water-soluble phosphobetaine compound.

  2. 2. The fountain solution composition for lithographic printing according to 1, wherein the water-soluble phosphobetaine compound is a compound having a phosphorylcholine group.

  3. 3. The fountain solution for lithographic printing according to 1 or 2, which is substantially free of a volatile organic solvent.

  4). After image exposure of the lithographic printing plate material, on-press development to a lithographic printing plate on a printing machine using the fountain solution for lithographic printing according to any one of 1 to 3, followed by printing An image forming method.

  According to the present invention, it has good on-press developability, and also has good on-press developability for a lithographic printing plate material after high-temperature storage, and it is difficult for stains on unexposed areas of printed matter to occur. A fountain solution for lithographic printing suitable for on-press development CTP, and an image forming method can be provided.

  It is also effective in dampening water that does not contain an organic solvent such as isopropanol, is stable with little change due to evaporation of the organic solvent, has good on-machine developability that can prevent VOC measures and avoid flammability problems. A fountain solution for lithographic printing suitable for on-press development CTP and an image forming method can be provided.

  Hereinafter, although the best mode for carrying out the present invention will be described, the present invention is not limited to these.

  Hereinafter, the present invention will be described in detail.

<Dampening water composition for lithographic printing>
The fountain solution is generally concentrated and commercialized when used on a commercial basis, and when used, such a concentrate is appropriately diluted and used as a fountain solution. In the present specification, the concentrated product is called a fountain solution for lithographic printing. The contents and addition amounts of various components mentioned below are based on the total mass of dampening water during use unless otherwise specified.

  The fountain solution composition for lithographic printing according to the present invention contains a water-soluble phosphobetaine compound.

  When a water-soluble phosphobetaine compound is used as the fountain solution for lithographic printing, the non-image area of the plate is uniformly wetted and is less likely to cause stains.

  Therefore, it has good on-press developability and has good on-press developability even for lithographic printing plate materials after high-temperature storage. A fountain solution for lithographic printing suitable for development CTP and an image forming method can be provided.

  In addition, when a water-soluble phosphobetaine compound is used, it is effective even in dampening water that does not substantially contain isopropanol or an organic solvent, is stable with little change due to evaporation of an organic solvent such as isopropanol, and is flammable. This problem can also be avoided.

  The water-soluble phosphobetaine compound according to the present invention will be described.

  Examples of the water-soluble phosphobetaine compound according to the present invention include compounds having the structure of the following general formula (1) (compounds represented by the general formula (1)).

(In general formula (1), R ₁ and R ₂ represent a hydrogen atom or an alkyl group, R ₃ represents a hydrocarbon group or an acyl group, and X represents an alkylene group having 1 to 3 carbon atoms.)
The water-soluble in the present invention means that 0.1 g or more is dissolved in 100 g of water at 20 ° C.

  In addition, the water-soluble phosphobetaine compound according to the present invention is preferably a compound having a phosphorylcholine group.

  Examples of the phosphorylcholine group include a structure represented by the following general formula (2) (group represented by the general formula (2)).

(Wherein R ¹ , R ² and R ³ are the same or different groups and represent an alkyl group or a hydroxyalkyl group having 1 to 8 carbon atoms, and R ⁴ represents — (CH ₂ —CHR ⁶ O) _m. — (CH ₂ —CHR ⁶ ) — group (wherein R ⁶ represents a hydrogen atom, a methyl group or an ethyl group, and m represents an integer of 0 to 10).
). R ⁵ represents — (CH ₂ ) _g — (where g is an integer of 0 to 10). )
In the general formula (2), examples of the alkyl group having 1 to 8 carbon atoms or hydroxyalkyl group represented by R ¹ , R ² , and R ³ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, A hexyl group, an isopropyl group, an isobutyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxyhexyl group and the like may be mentioned, which may be the same or different. From the viewpoint of availability, a methyl group is preferable.

Specific examples of R ⁴ include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an ethoxylene ethylene group, a propyleneoxypropylene group, a poly (ethyleneoxy) ethylene group, and a poly (propyleneoxy) propylene group. Etc.

Specific examples of R ⁵ include a methylene group, an ethylene group, a propylene group, and a butylene group.

  The water-soluble phosphobetaine compound used in the present invention is preferably a polymer having the phosphorylcholine group (hereinafter abbreviated as PC group) in the side chain (hereinafter abbreviated as PC polymer).

  The PC polymer can be obtained, for example, by homopolymerizing a monomer having a group represented by the general formula (2) (abbreviated as PC monomer) or copolymerizing with another monomer. . The PC monomer may have a polymerizable double bond and a group represented by the general formula (2) in the molecule. As a PC monomer, the monomer represented by following General formula (3) is mentioned, for example.

(In the formula, R ¹ , R ² and R ³ are the same or different groups and represent an alkyl group or a hydroxyalkyl group having 1 to 8 carbon atoms, and n represents an integer of 2 to 4. ⁷ represents a hydrogen atom or a methyl group.)
In the general formula (3), the alkyl group having 1 to 8 carbon atoms represented by R ¹ , R ² and R ³ is methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, isopropyl group. And an isobutyl group, and the hydroxyalkyl group includes a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxyhexyl group, and the like, which may be the same or different. From the viewpoint of availability, a methyl group is preferable.

  Specific examples of the monomer (PC monomer) represented by the formula (3) include, for example, 2- (meth) acryloyloxyethyl-2 ′-(trimethylammonio) ethyl phosphate, 3- (meth) Acryloyloxypropyl-2 '-(trimethylammonio) ethyl phosphate, 4- (meth) acryloyloxybutyl-2'-(trimethylammonio) ethyl phosphate, 5- (meth) acryloyloxypentyl-2 '-(trimethylammoni) E) Ethyl phosphate, 2- (meth) acryloyloxyethyl-2 ′-(triethylammonio) ethyl phosphate, 3- (meth) acryloyloxypropyl-2 ′-(triethylammonio) ethyl phosphate, 4- (meth) Acryloyloxybutyl-2 '-(triethylammonio) Tyl phosphate, 5- (meth) acryloyloxypentyl-2 '-(triethylammonio) ethyl phosphate, 2- (meth) acryloyloxyethyl-2'-(tripropylammonio) ethyl phosphate, 3- (meth) acryloyl Oxypropyl-2 '-(tripropylammonio) ethyl phosphate, 4- (meth) acryloyloxybutyl-2'-(tripropylammonio) ethyl phosphate, 5- (meth) acryloyloxypentyl-2 '-(tri Propylammonio) ethyl phosphate, 2- (meth) acryloyloxyethyl-2 '-(tributylammonio) ethyl phosphate, 3- (meth) acryloyloxypropyl-2'-(tributylammonio) ethyl phosphate, 4- ( Meta) Liloyloxybutyl-2 '-(tripropylammonio) ethyl phosphate, 5- (meth) acryloyloxypentyl-2'-(tributylammonio) ethyl phosphate, 2- (meth) acryloyloxyethyl-3 '-( Trimethylammonio) propyl phosphate, 2- (meth) acryloyloxyethyl-4 '-(trimethylammonio) butyl phosphate, 2- (meth) acryloyloxyethyl-3'-(triethylammonio) propyl phosphate, 2- ( (Meth) acryloyloxyethyl-4 '-(triethylammonio) butyl phosphate, 2- (meth) acryloyloxyethyl-3'-(tripropylammonio) propyl phosphate, 2- (meth) acryloyloxyethyl-4'- (Tripro Pyrammonio) butyl phosphate.

  Further, 2- (meth) acryloyloxyethyl-3 '-(tributylammonio) propyl phosphate, 2- (meth) acryloyloxyethyl-4'-(tributylammonio) butyl phosphate, 3- (meth) acryloyloxypropyl -3 '-(trimethylammonio) propyl phosphate, 3- (meth) acryloyloxypropyl-4'-(trimethylammonio) butyl phosphate, 3- (meth) acryloyloxypropyl-3 '-(triethylammonio) propyl Phosphate, 3- (meth) acryloyloxypropyl-4 '-(triethylammonio) butyl phosphate, 3- (meth) acryloyloxypropyl-3'-(tripropylammonio) propyl phosphate, 3- (meth) acryloyl Oxypropyl-4 '-(tripropylammonio) butyl phosphate, 3- (meth) acryloyloxypropyl-3'-(tributylammonio) propyl phosphate, 3- (meth) acryloyloxypropyl-4 '-(tributylammoni) E) Butyl phosphate, 4- (meth) acryloyloxybutyl-3 '-(trimethylammonio) propyl phosphate, 4- (meth) acryloyloxybutyl-4'-(trimethylammonio) butyl phosphate, 4- (meth) Acryloyloxybutyl-3 '-(triethylammonio) propyl phosphate, 4- (meth) acryloyloxybutyl-4'-(triethylammonio) butyl phosphate, 4- (meth) acryloyloxybutyl-3 '-(tripropyl) Nmonio) propyl phosphate, 4- (meth) acryloyloxybutyl-4 '-(tripropylammonio) butyl phosphate, 4- (meth) acryloyloxybutyl-3'-(tributylammonio) propyl phosphate, 4- (meta ) Acryloyloxybutyl-4 '-(tributylammonio) butyl phosphate.

  Furthermore, the derivative | guide_body of monomers, such as maleic acid, fumaric acid, itaconic acid which have 1-2 groups represented by General formula (2), etc. can be mentioned.

Among the PC monomers, a monomer represented by the general formula (3) is preferable, and R ¹ , R ² , R ^{3 in the} general formula (3) are particularly studied and various points have been studied from the viewpoint of availability. Are both methyl groups, R ⁷ is a methyl group, and n is 2, 2-methacryloyloxyethyl-2 ′-(trimethylammonio) ethyl phosphate (hereinafter sometimes abbreviated as MPC) is preferable. MPC is represented by the following general formula (4).

  The PC monomers may be used alone for polymerization, or two or more types may be mixed and used for polymerization.

  Examples of other monomers copolymerized with the PC monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n- Alkyl (meth) acrylates such as dodecyl (meth) acrylate, cyclohexyl (meth) acrylate, n-stearyl (meth) acrylate and isostearyl (meth) acrylate; 3-{(meth) acryloyloxypropyl} trimethoxysilane, 3- Silyl group-containing (meth) acrylates such as {(meth) acryloyloxypropyl} triateoxysilane, 3-{(meth) acryloyloxypropyl} tripropyloxysilane; 2- (perfluorooctyl) ethyl (meth) acrylate, 1H, 1H, 5H-O Fluorine-based (meth) acrylates such as tafluoropentyl (meth) acrylate, 1H, 1H, 7H-dodecafluoroheptyl (meth) acrylate, 2,2,2-trifluoro-1-trifluoromethylethyl (meth) acrylate; Hydroxyl group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and polypropylene glycol mono (meth) acrylate; (meth) acrylic acid amide, N Amide monomers such as N-dimethyl (meth) acrylic acid amide; (meth) acrylic acid. Furthermore, as other monomers, for example, substituted or unsubstituted styrene monomers such as styrene, methylstyrene, chloromethylstyrene; vinyl ether monomers such as ethyl vinyl ether and butyl vinyl ether; vinyl esters such as vinyl acetate Monomers; vinyl silane monomers such as trimethoxyvinyl silane and triate xyl vinyl silane; substituted or unsubstituted hydrocarbon monomers such as ethylene, propylene, isobutylene, vinyl chloride, vinylidene chloride; diethyl fumarate, diethyl Examples thereof include dibasic acid ester monomers such as malate; N-vinylpyrrolidone and the like. Among these monomers, more preferred are hydroxyl group-containing (meth) acrylates, alkyl (meth) acrylates, styrene monomers, and vinylsilane monomers. Among them, a methacrylic acid ester having an alkyl group having 4 to 18 carbon atoms or a hydroxyalkyl group is more preferable in view of characteristics.

  Specific examples of the PC polymer used in the present invention include, for example, a polymer of (2-((meth) acryloyloxy) ethyl-2 ′-(trimethylammonio) ethyl phosphate), and (2-((meta ) Acryloyloxy) ethyl-2 '-(trimethylammonio) ethyl phosphate) -butyl (meth) acrylate copolymer, 2-((meth) acryloyloxy) ethyl-2'-(trimethylammonio) ethyl phosphate-lauryl (Meth) acrylate copolymer, (2-((meth) acryloyloxy) ethyl-2 '-(trimethylammonio) ethyl phosphate) -polypropylene glycol mono (meth) acrylate copolymer, 2-((meth) acryloyl Oxy) ethyl-2 '-(trimethylammonio) ethyl phosphate Butyl methacrylate-2-hydroxyethyl methacrylate terpolymer, 2-((meth) acryloyloxy) ethyl-2 '-(trimethylammonio) ethyl phosphate-polypropylene glycol mono (meth) acrylate- (meth) acrylic acid 3 Preferred examples include copolymers containing 2-((meth) acryloyloxy) ethyl-2 '-(trimethylammonio) ethyl phosphate, which is a phospholipid-like monomer such as an original copolymer.

  Even if isopropyl alcohol is replaced by using a fountain solution containing 0.005 to 1% by mass, preferably 0.01 to 0.5% by mass of the above water-soluble phosphobetaine compound, it is satisfactory. Demonstrate printability. Further, after the fountain solution is applied, even if the water droplets remaining on the plate at the time of printing stop are left to evaporate and become concentrated, the image area of the plate is not affected.

  The fountain solution composition for lithographic printing of the present invention further comprises a bromonitroalcohol compound, a 1,2-benzisothiazolin-3-one compound, a p-hydroxybenzoic acid derivative, an azole compound, and a heterocyclic alkylammonium salt. At least one compound selected from the group consisting of:

  Bromonitroalcohol compounds that can be used in the present invention include compounds represented by the following general formulas [A] to [C].

(In the formula, R _{1 to} R ₁₃ each independently represents a hydrogen atom or an alkyl group.)
When R _{1 to} R ₁₃ in the general formulas [A] to [C] represent an alkyl group, a lower alkyl group is preferable, particularly an alkyl group having 1 to 3 carbon atoms such as a methyl group, an ethyl group, a propyl group, An isopropyl group or the like is suitable. One or more of these bromonitroalcohol compounds can be used.

  Particularly preferred among the bromonitroalcohol compounds that can be used in the present invention are 2-bromo-2-nitropropane-1,3-diol (pronopol), 1,1-dibromo-1-nitro-2- Ethanol (DBNE), 1,1-dibromo-1-nitro-2-propanol (DBNP), 3-bromo-3-nitropentane-2,4-diol, and the like. Many bromonitroalcohol compounds are poorly water-soluble substances, but can be used by dissolving in methanol or glycol organic solvents. Further, it can be used as a fountain solution by using an anionic, cationic or nonionic surfactant in combination without using an organic solvent.

  The range of the content of the bromonitroalcohol compound in the fountain solution is suitably 0.001 to 5% by mass, preferably 0.005 to 3% by mass.

  Next, the 1,2-benzisothiazolin-3-one compound will be described. Among the 1,2-benzisothiazolin-3-one compounds, one that is preferably used is 1,2-benzisothiazolin-3-one having the following structural formula.

(In the formula, R represents a hydrogen atom or an alkyl group, X represents an alkyl group, an alkoxy group, or a halogen atom, and n represents 0 or an integer of 1 to 4).
In the above formula, when R represents an alkyl group, a lower alkyl group is preferred, specifically an alkyl group having 1 to 4 carbon atoms, and particularly a methyl group. When X represents an alkyl group, a lower alkyl group is preferable, and an alkyl group having 1 to 4 carbon atoms is particularly preferable. When X represents an alkoxy group, an alkoxy group having 1 to 4 carbon atoms is preferable. When X represents a halogen atom, a chlorine atom or a bromine atom is preferable.

  In the fountain solution used in the present invention, one or more 1,2-benzisothiazolin-3-one compounds can be used.

  Among the 1,2-benzisothiazolin-3-one compounds used in the present invention, the following are preferably used.

  The range of the content of the 1,2-benzisothiazolin-3-one compound in the fountain solution is suitably 0.001 to 5% by mass, preferably 0.005 to 3% by mass.

  Examples of p-hydroxybenzoic acid derivatives that can be used in the present invention include isobutyl p-hydroxybenzoate, isopropyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, butyl p-hydroxybenzoate, p-hydroxybenzoate. Examples include propyl acid, methyl p-hydroxybenzoate, vinyl p-hydroxybenzoate, and the like.

  In the fountain solution used in the present invention, one or more p-hydroxybenzoic acid derivatives can be used.

  0.001-5 mass% is suitable for the range of content of the p-hydroxybenzoic acid derivative in dampening water, Preferably it is 0.005-3 mass%.

  Examples of azole compounds that can be used in the present invention include α- (4-chlorophenyl) -α- (1-cyclopropylethyl) -1H-1,2,4-triazole-1-ethanol (generic name: silane). Proconazole), (±) α- [2- (4-chlorophenyl) ethyl] -α- (1,1-dimethylethyl) -1H-1,2,4-triazole-1-ethanol (generic name: tebuconazole) And 1-[[2- (2,4-dichlorophenyl) -4-n-propyl-1,3-dioxolan-2-yl] methyl] -1H-1,2,4-triazole (generic name: propico) Nazole). One or more azole compounds can be used for the fountain solution.

  0.001-5 mass% is suitable for the range of content of the azole compound in dampening water, Preferably it is 0.005-3 mass%.

  The heterocyclic alkylammonium salt that can be used in the present invention is one or more heterocyclic alkylammonium salts selected from the group consisting of alkyl-pyridinium salts, alkyl-quinolinium salts, and alkyl-isoquinolinium salts. Among them, those having an alkyl group having 8 to 18 carbon atoms are preferable. For example, lauryl isoquinolinium chloride, cetyl pyridinium chloride and the like can be mentioned.

  0.001-5 mass% is suitable for the range of content of the heterocyclic alkyl ammonium salt in the fountain solution, Preferably it is 0.005-3 mass%.

  The fountain solution composition for lithographic printing according to the present invention comprises a bromonitroalcohol compound, a 1,2-benzisothiazolin-3-one compound, a p-hydroxybenzoic acid derivative, an azole compound, and a heterocyclic alkylammonium salt. In the case of containing at least two kinds of compounds selected from the group, the total content thereof is suitably in the range of 0.001 to 5% by mass in the fountain solution.

  A water-soluble polymer compound may be further added to the fountain solution for lithographic printing of the present invention.

  Specific examples of such water-soluble polymer compounds include gum arabic, starch derivatives (eg, dextrin, enzymatically degraded dextrin, hydroxypropylated enzymatically degraded dextrin, carboxymethylated starch, phosphate starch, octenyl succinated starch), alginic acid. Natural products of salts, fiber derivatives (such as carboxymethylcellulose, carboxyethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxypropylmethylcellulose, and their glyoxal modified products) and modified products thereof, polyvinyl alcohol and derivatives thereof, polyvinylpyrrolidone, polyacrylamide and Copolymers, polyacrylic acid and its copolymers, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, etc. Thing, and the like. These polymer compounds can be used alone or as a mixture, and the range of the content thereof is 0.0001 to 5 mass%, more preferably 0.003 to 1 mass% in dampening water.

  In the present invention, among the above water-soluble polymer compounds, polyvinyl pyrrolidone can be particularly preferably used. The polyvinylpyrrolidone contained in the fountain solution for lithographic printing means a homopolymer of vinylpyrrolidone. Polyvinylpyrrolidone having a molecular weight of 200 to 3,000,000 is appropriate, preferably having a molecular weight of 300 to 500,000, more preferably 300 to 100,000. Particularly preferred is 300 to 30,000.

  These polyvinyl pyrrolidones can be used alone or in combination of two or more kinds having different molecular weights. Further, it can be combined with a low molecular weight polyvinyl pyrrolidone, for example, a vinyl pyrrolidone oligomer having a polymerization degree of 3 to 5.

  As such polyvinyl pyrrolidone, a commercially available product can be used. For example, various great grades such as K-15, K-30, K-60, K-90, K-120 manufactured by ISP can be used.

  The range of the content of polyvinylpyrrolidone in the fountain solution is suitably 0.001 to 0.3% by mass, preferably 0.005 to 0.2% by mass.

  The fountain solution composition for lithographic printing according to the present invention preferably contains at least one selected from the group consisting of sugars and glycerin. The sugar to be used can be selected from monosaccharides, disaccharides, oligosaccharides, and the like, and includes sugar alcohols obtained by hydrogenation. Specific examples include D-erythrose, D-throse, D-arabinose, D-ribose, D-xylose, D-erythro-pentulose, D-allulose, D-galactose, D-glucose, D-mannose, D-talose, β -D-fructose, α-L-sorbose, 6-deoxy-D-glucose, D-glycero-D-galactose, α-D-allo-heptulose, β-D-alto-3-heptulose, saccharose, lactose, D Maltose, isomaltose, inulobiose, hyalbiouron, maltotriose, D, L-arabit, rebit, xylit, D, L-sorbit, D, L-mannit, D, L-digit, D, L-talit, zulcit , Allozulcit, maltitol, reduced water candy, etc. It is. These saccharides may be used alone or in combination of two or more.

  Glycerin may be used alone or in combination with sugars.

  In the fountain solution, the content range of at least one selected from the group consisting of saccharides and glycerin is suitably 0.01 to 1% by mass, preferably 0.05 to 0.5% by mass.

  It is desirable that the fountain solution is generally used in the acidic region, that is, in the range of pH 3 to 7. When the pH is less than 3, the etching effect on the support becomes strong and the printing durability may be lowered, and the above range is preferable. In order to adjust the pH value to 3 to 7, generally, at least one selected from water-soluble organic acids, inorganic acids and salts thereof can be used. These compounds are effective in adjusting the pH of the fountain solution or buffering the pH, and appropriate etching or anticorrosion of the lithographic printing plate support. Preferred organic acids include, for example, citric acid, ascorbic acid, malic acid, tartaric acid, lactic acid, acetic acid, gluconic acid, hydroxyacetic acid, succinic acid, malonic acid, levulinic acid, sulfanilic acid, p-toluenesulfonic acid, phytic acid, and organic phosphones. An acid etc. are mentioned. Examples of the inorganic acid include phosphoric acid, nitric acid, sulfuric acid, and polyphosphoric acid. Further, alkali metal salts, alkaline earth metal salts or ammonium salts of these organic acids and / or inorganic acids, and organic amine salts are also preferably used, and one of these organic acids, inorganic acids and salts thereof is used alone. Or you may use it as a mixture of 2 or more types. In this case, the content of dampening water at the time of use is suitably in the range of 0.0002 to 0.1 mol / liter in combination of organic acid, inorganic acid and their salts. The fountain solution for lithographic printing according to the present invention also contains an alkali metal hydroxide, phosphoric acid, alkali metal salt, alkali carbonate metal salt, silicate, etc., and has a pH of 7 to 11 as a fountain solution. It can also be used in the alkaline region.

  In addition to the above components, a chelate compound can also be added to the fountain solution composition for lithographic printing of the present invention. Usually, the fountain solution composition for lithographic printing, which is a concentrated solution, is diluted by adding tap water, well water or the like, and used as a fountain solution. At this time, calcium ions or the like contained in the tap water or well water to be diluted may affect the printing and cause the printed matter to be easily stained. In such a case, the above disadvantages can be eliminated by adding a chelate compound. Preferred chelate compounds include, for example, ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, potassium salt thereof, sodium salt thereof; hydroxyethylethylenediaminetriacetic acid Nitrilotriacetic acid, its potassium salt, its sodium salt; 1,2-diaminocyclohexanetetraacetic acid, its potassium salt, its sodium salt; 1,3-diamino-2-propanoltetraacetic acid, its Aminopolycarboxylic acids such as potassium salt and sodium salt thereof, 2-phosphonobutanetricarboxylic acid-1,2,4, potassium salt and sodium salt thereof; 2-phosphonobutanetricarboxylic acid- , 3,4, its potassium salt, its sodium salt; 1-phosphonoethanetricarboxylic acid-1,2,2, its potassium salt, its sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, its potassium salt Organic phosphonic acids or phosphonoalkanetricarboxylic acids such as aminotri (methylenephosphonic acid), potassium salt, sodium salt, and the like.

  Organic amine salts are also effective in place of the sodium or potassium salts of the above chelating agents.

  These chelating agents are selected so that they are stably present in the dampening water and do not impair the printability. The range of the amount contained is suitably 0.001 to 3% by mass, preferably 0.01 to 1% by mass in dampening water.

  The fountain solution composition for lithographic printing of the present invention may further contain a colorant, a rust inhibitor, an antifoaming agent, and the like. Food coloring agents and the like can be preferably used as the colorant. For example, CINo. 19140, 15985 and CI No. 16185, 45430, 16255, 45380, 45100, and purple pigments such as CI No. 42640, as a blue pigment, CI No. 42090 and 73015, CINo. 42095, and the like.

  Examples of the rust preventive include benzotriazole, 5-methylbenzotriazole, thiosalicylic acid, benzimidazole and derivatives thereof.

  As the antifoaming agent, a silicon antifoaming agent is preferable, and any of an emulsified dispersion type and a solubilized type can be used.

  The fountain solution composition for lithographic printing according to the present invention further includes a corrosion inhibitor such as magnesium nitrate, zinc nitrate, calcium nitrate, sodium nitrate, potassium nitrate, lithium nitrate and ammonium nitrate, and a hardening agent such as a chromium compound and an aluminum compound. , Cyclic ether: containing, for example, an organic solvent such as 4-butyrolactone, a water-soluble surface active organometallic compound described in JP-A No. 61-193893, and the like in a range of 0.0001 to 1% by mass of dampening water. You can also.

  The fountain solution composition for lithographic printing of the present invention may further contain a small amount of a surfactant.

  For example, anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid salts, linear alkyl benzene sulfonic acid salts, branched alkyl benzene sulfonic acid salts, alkyl naphthalene. Sulfonates, alkylphenoxy polyoxyethylenepropyl sulfonates, polyoxyethylene alkylsulfophenyl ether salts, N-methyl-N-oleyl taurine sodium, N-alkylsulfosuccinic acid monoamide disodium salts, petroleum sulfonates, Hydrogenated castor oil, sulfated beef tallow oil, fatty acid alkyl ester sulfate ester salt, alkyl sulfate ester salt, polyoxyethylene alkyl ether sulfate ester salt, fatty acid monoglyceride Acid ester salts, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates, styrene Examples thereof include partially saponified products of maleic anhydride copolymers, partially saponified products of olefin-maleic anhydride copolymers, and naphthalene sulfonate formalin condensates. Among these, dialkyl sulfosuccinates, alkyl sulfates and alkyl naphthalene sulfonates are particularly preferably used.

  Nonionic surfactants include polyoxyalkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxypropylene alkyl ether, glycerin fatty acid partial esters, sorbitan fatty acid moieties. Esters, pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid partial esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyglycerin fatty acid partial esters, poly Oxyethylenated castor oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxy Alkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, such as trialkylamine oxides. Of these, polyoxyethylene alkylphenyl ethers, polyoxyethylene-polyoxypropylene block polymers and the like are preferably used.

Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, polyethylene polyamine derivatives, and the like. Examples of amphoteric surfactants include alkyl imidazolines. In addition, examples of the fluorine-based anionic surfactant include fluorine-based surfactants, such as perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkyl phosphate esters, and fluorine-based nonionic surfactants. Examples of the perfluoroalkylethylene oxide adduct, perfluoroalkylpropylene oxide adduct, and fluorine-based cationic surfactant include perfluoroalkyltrimethylammonium salts.
In consideration of foaming, the content of these surfactants is 10% by mass or less, preferably 0.01 to 3.0% by mass in dampening water.

  Further, the fountain solution composition for lithographic printing according to the present invention may contain glycols and / or alcohols as a wetting agent. Examples of such a wetting agent include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol. Monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monopropyl ether, triethylene glycol monopropyl ether, tetraethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, triethylene glycol monoisopropyl ether Tetraethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, triethylene glycol monoisobutyl ether, tetraethylene glycol Monoisobutyl ether, ethylene glycol monotertiary butyl ether, diethylene glycol monotertiary butyl ether, triethylene glycol monotertiary butyl ether, tetraethylene glycol monotertiary butyl ether, propylene glycol monomethyl ether, dipropylene glycol mono Chill ether, tripropylene glycol monomethyl ether, tetrapropylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monoethyl ether, tetrapropylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol Monopropyl ether, tripropylene glycol monopropyl ether, tetrapropylene glycol monopropyl ether, propylene glycol monoisopropyl ether, dipropylene glycol monoisopropyl ether, tripropylene glycol monoisopropyl ether, tetrapropylene glycol monoisopropyl ether, propylene glycol Cole monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, tetrapropylene glycol monobutyl ether, propylene glycol monoisobutyl ether, dipropylene glycol monoisobutyl ether, tripropylene glycol monoisobutyl ether, tetrapropylene glycol monoisobutyl ether, propylene Glycol monotertiary butyl ether, dipropylene glycol monotertiary butyl ether, tripropylene glycol monotertiary butyl ether, tetrapropylene glycol monotertiary butyl ether, polypropylene glycol having a molecular weight of 200 to 1000 and their monomethyl ether, monoethyl ether, monopro Ether, monoisopropyl ether and monobutyl ether, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol and pentapropylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, butylene glycol, hexylene glycol, ethyl alcohol, n-propyl alcohol, benzyl alcohol, ethylene glycol monophenyl ether, 2-ethyl-1,3-hexanediol, 3-methoxy-3-methyl-1-butanol, 1-butoxy-2-propanol, diglycerin, polyglycerin , Trimethylolpropane, pentaerythritol, methoxyethanol, ethoxyethanol, butoxyeta Lumpur, such as 3-methoxy butanol.

  These wetting agents can be used alone or in combination of two or more in a range of 0.01 to 1% by mass in dampening water.

  The balance is water as a component of the fountain solution composition for lithographic printing according to the present invention.

  Accordingly, in consideration of the content of the various components in the fountain solution and the dilution rate of the fountain solution composition, water, preferably demineralized water, i.e., pure water, is used to adjust the various components at appropriate concentrations. A fountain solution for lithographic printing which is dissolved and can be obtained as a concentrated liquid can be obtained. Such a concentrated solution is diluted about 10 to 200 times with tap water, well water or the like during normal use to obtain a dampening water during use.

  The fountain solution composition for lithographic printing according to the present invention can completely replace isopropyl alcohol without using it together with a volatile organic solvent. Therefore, the fountain solution for lithographic printing according to the present invention can be a fountain solution for lithographic printing that does not substantially contain a volatile organic solvent. Here, “substantially free of volatile organic solvent” means that the amount of volatile organic solvent is 10% by mass or less in the fountain solution for lithographic printing, which is a concentrated solution, according to the measurement method of ASTM D 2369-95. It means that.

  ASTM D 2369-95 is a method for determining the amount of a volatile organic solvent by the following formula using a 3 ml sample in a hot air oven at 110 ° C. for 1 hour.

Formula: {(mass of sample−mass of heating residue−mass of moisture in sample) / (mass of sample)} × 100 = amount of volatile organic solvent (mass%)
Further, even when isopropyl alcohol is used in the range of 1 to 15% by mass in dampening water during use, there is no problem in print quality.

<Lithographic printing plate material>
The fountain solution composition for lithographic printing of the present invention can be used for various lithographic printing plate materials. In particular, a photosensitive lithographic printing plate having an aluminum plate as a support and a photosensitive layer thereon ( A printing plate to which photosensitivity has been imparted in advance, called a PS plate) can be suitably used for a lithographic printing plate obtained by image exposure and development. The preferred PS plate is a mixture of a diazo resin (a salt of a condensate of p-diazodiphenylamine and paraformaldehyde) and a shellac as described in British Patent 1,350,521, for example. A photosensitive layer comprising an aluminum plate, a diazo resin and a hydroxyethyl methacrylate unit as described in British Patent Nos. 1,460,978 and 1,505,739, or A photosensitive layer comprising a mixture of a polymer having a hydroxyethyl acrylate unit as a main repeating unit provided on an aluminum plate, and containing a dimethylmaleimide group described in JP-A-2-236552 and JP-A-4-274429 A negative PS plate, such as a photosensitive polymer system on an aluminum plate And a photosensitive layer comprising a mixture of O- Kinonjiado photosensitive material and a novolac-type phenolic resins as described in JP-A-50-125806 includes positive PS plate provided on the aluminum plate. It can also be used for a positive PS plate that has been burned.

  In the composition forming the photosensitive layer, an alkali-soluble resin other than the alkali-soluble novolak resin can be blended as necessary. For example, styrene-acrylic acid copolymer, methyl methacrylate-methacrylic acid copolymer, alkali-soluble polyurethane resin, alkali-soluble vinyl resin described in JP-B-52-28401, alkali-soluble polybutyral resin, and the like. it can. Further, a PS plate in which a photosensitive layer of a photopolymerizable photopolymer composition as described in U.S. Pat. Nos. 4,072,528 and 4,072,527 is provided on an aluminum plate, PS plate in which a photosensitive layer made of a mixture of an azide and a water-soluble polymer as described in British Patent Nos. 1,235,281 and 1,495,861 is provided on an aluminum plate Is also preferable.

  Furthermore, it can also be suitably used for a lithographic printing plate material (CTP plate) for CTP that is directly exposed with a visible or infrared laser. Specific examples include a photopolymer type digital plate (for example, Kodak GC Co., Ltd .: Exthermo TP-W) and a thermal positive type digital plate (for example, Fuji Film Co., Ltd .: HP-F). .

  In particular, in the case of the lithographic printing plate material (CTP plate) for CTP, the water-soluble phosphobetaine compound is considered to have a function of adsorbing the phosphorylcholine group to the support surface. For this reason, when the fountain solution for lithographic printing of the present invention containing a water-soluble phosphobetaine compound is used, it is considered that a thin layer of the phosphobetaine compound is formed at the interface between the image forming layer and the support. It is considered that the on-press developability of the unexposed area is improved by this functioning as a kind of release layer. Further, even in the case of a lithographic printing plate material stored over time due to this action effect, excellent on-press developability can be exhibited.

  By using the water-soluble phosphobetaine compound, a good on-press developability is obtained even in a region where the content of the water-soluble compound, which will be described later, used for imparting on-press developability is small in the image forming layer. Will be able to. In addition, it is possible to use a lithographic printing plate material with a reduced content of water-soluble compounds in the image forming layer, and the water-soluble components remaining in the coating film on the image area are reduced, improving the image strength and water resistance. As a result, printing durability and chemical resistance are improved.

  Examples of the image forming layer include image forming layers containing microcapsules enclosing thermoplastic particles (heat-melting particles and heat-fusible particles) and hydrophobic materials described later.

(Example of lithographic printing plate material for on-press development CTP)
A planographic printing plate material for on-press development CTP that can be preferably used in the present invention will be described below with a preferred example.

  Examples of the image forming layer include image forming layers containing microcapsules encapsulating thermoplastic particles (heat-fusible particles, heat-fusible particles) described later and hydrophobic materials. More preferably, the image forming layer may contain the water-soluble phosphobetaine compound.

(Thermoplastic resin particles)
The thermoplastic resin particles are thermoplastic resin particles, and the average particle size of the particles needs to be in the range of 10 to 600 nm. The average particle diameter is further preferably in the range of 20 to 300 nm, and more preferably in the range of 40 to 150 nm.

  The average particle diameter referred to here is the average value obtained from the values of these particle diameters by measuring the particle diameter by observing 100 particles with a scanning electron microscope as the average value of the long diameter and the short diameter. Value.

  A plurality of types of thermoplastic resin particles having different average particle diameters within the above range can be mixed and used. In this case, the thermoplastic resins may be the same or different.

  Specific examples of the thermoplastic resin particles include the following.

  Examples of the thermoplastic resin particles used in the present invention include heat-fusible particles and heat-fusible particles.

  The heat-meltable particles are particles formed of a material that has a low viscosity when melted, and is generally classified as a wax, among thermoplastic materials. The physical properties are preferably a softening point of 40 ° C. or higher and 120 ° C. or lower, a melting point of 60 ° C. or higher and 150 ° C. or lower, more preferably a softening point of 40 ° C. or higher and 100 ° C. or lower, and a melting point of 60 ° C. or higher and 120 ° C. or lower.

  Usable materials include paraffin, polyolefin, polyethylene wax, microcrystalline wax, fatty acid wax and the like. These preferably have a molecular weight of about 800 to 10,000. In addition, these waxes can be oxidized to introduce polar groups such as hydroxyl groups, ester groups, carboxyl groups, aldehyde groups and peroxide groups. Furthermore, in order to lower the softening point and improve the workability, these waxes are stearamide, linolenamide, laurylamide, myristamide, hardened beef fatty acid amide, palmitoamide, oleic acid amide, rice sugar fatty acid amide, coconut fatty acid amide. Alternatively, methylolated products of these fatty acid amides, methylene bisstellaramide, ethylene bisstellaramide, and the like can be added. Coumarone-indene resin, rosin-modified phenol resin, terpene-modified phenol resin, xylene resin, ketone resin, acrylic resin, ionomer, and copolymers of these resins can also be used.

  Among these, it is preferable to contain any of polyethylene, microcrystalline, fatty acid ester, and fatty acid. Since these materials have a relatively low melting point and a low melt viscosity, high-sensitivity image formation can be performed.

  The heat-meltable particles are preferably dispersible in water.

  Moreover, the composition of the inside and the surface layer of the heat-meltable particles may be continuously changed, or may be coated with a different material.

  As a coating method, a known microcapsule formation method, a sol-gel method, or the like can be used.

  Examples of the heat-fusible particles include thermoplastic polymer particles, and there is no specific upper limit for the softening temperature of the polymer particles, but the temperature is preferably lower than the decomposition temperature of the polymer particles. . The weight average molecular weight (Mw) of the polymer is preferably in the range of 10,000 to 1,000,000.

  Specific examples of the polymer constituting the polymer particles include, for example, diene (co) polymers such as polypropylene, polybutadiene, polyisoprene, and ethylene-butadiene copolymer, styrene-butadiene copolymer, Synthetic rubbers such as methyl methacrylate-butadiene copolymer, acrylonitrile-butadiene copolymer, polymethyl methacrylate, methyl methacrylate- (2-ethylhexyl acrylate) copolymer, methyl methacrylate-methacrylic acid copolymer, methyl acrylate- ( N-methylolacrylamide) copolymer, (meth) acrylic acid ester such as polyacrylonitrile, (meth) acrylic acid (co) polymer, polyvinyl acetate, vinyl acetate-vinyl propionate copolymer, vinyl acetate-ethylene copolymer Vinyl such as polymer Ester (co) polymer, vinyl acetate - (2-ethylhexyl acrylate) copolymers, polyvinyl chloride, polyvinylidene chloride, polystyrene and copolymers thereof. Of these, (meth) acrylic acid esters, (meth) acrylic acid (co) polymers, vinyl ester (co) polymers, polystyrene, and synthetic rubbers are preferably used.

  The heat-fusible particles are preferably dispersible in water.

  Further, the composition of the heat fusible particles may vary continuously between the inside and the surface layer, or may be coated with a different material. As a coating method, a known microcapsule formation method, a sol-gel method, or the like can be used.

  The range of the content of the thermoplastic resin particles in the image forming layer is 50 to 90% by mass with respect to the total solid content of the image forming layer in terms of sensitivity, on-press development property, and printing durability, and 55 It is preferable that it is -80 mass%, and it is more preferable that it is 60-75 mass%.

  The image forming layer preferably contains a photothermal conversion agent.

(Photothermal conversion agent)
The photothermal conversion agent is a material that can convert exposure light into heat to form an image on the image forming layer. Examples of the photothermal conversion agent include the following dyes and pigments.

  Examples of the dye include organic compounds such as cyanine dyes, croconium dyes, polymethine dyes, azurenium dyes, squalium dyes, thiopyrylium dyes, naphthoquinone dyes, anthraquinone dyes, which are general infrared absorbing dyes, phthalocyanines , Naphthalocyanine-based, azo-based, thioamide-based, dithiol-based, and indoaniline-based organometallic complexes. Specifically, JP-A-63-139191, JP-A-64-33547, JP-A-1-160683, JP-A-1-280750, JP-A-1-293342, JP-A-2-2074, Kaihei 3-26593, JP-A-3-30991, JP-A-3-34891, JP-A-3-36093, JP-A-3-36094, JP-A-3-36095, JP-A-3-42281, JP-A-3-42281 Examples thereof include compounds described in JP-A-3-97589, JP-A-3-103476, and the like. These can be used alone or in combination of two or more.

  JP-A-11-240270, JP-A-11-265062, JP-A-2000-309174, JP-A-2002-49147, JP-A-2001-162965, JP-A-2002-144750, JP-A-2001-219667. The compounds described in 1 can also be preferably used.

  Examples of the pigment include carbon, graphite, metal, metal oxide and the like.

  As carbon, furnace black or acetylene black is particularly preferable. The particle size (d50) is preferably 100 nm or less, and more preferably 50 nm or less.

  As the graphite, fine particles having a particle size of 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less can be used.

  As the metal, any metal can be used as long as the particle diameter is 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less. The shape may be any shape such as a spherical shape, a piece shape, or a needle shape. Colloidal metal fine particles (Ag, Au, etc.) are particularly preferable.

  As the metal oxide, a material that is black in the visible light region, or a material that has conductivity or is a semiconductor can be used.

  Examples of the former include black iron oxide and black composite metal oxides containing two or more metals.

Examples of the latter include Sb-doped SnO ₂ (ATO), Sn-added In ₂ O ₃ (ITO), TiO ₂ , and TiO ₂ reduced TiO (titanium oxynitride, generally titanium black). Can be mentioned. Further, it can also be used those obtained by coating the core material _{(BaSO 4, TiO 2, 9Al} 2 O 3 · 2B 2 O, K 2 O · nTiO 2 , etc.) in these metal oxides. These particle sizes are 0.5 μm or less, preferably 100 nm or less, and more preferably 50 nm or less.

  Among these photothermal conversion materials, black iron oxide and black composite metal oxides containing two or more metals are more preferable materials.

The black iron oxide (Fe ₃ O ₄ ) is preferably particles having an average particle diameter of 0.01 to 1 μm and an acicular ratio (major axis diameter / minor axis diameter) of 1 to 1.5. It is preferably substantially spherical (acicular ratio 1) or has an octahedral shape (acicular ratio about 1.4).

  Examples of such black iron oxide particles include TAROX series manufactured by Titanium Industry Co., Ltd. As the spherical particles, BL-100 (particle size: 0.2 to 0.6 μm), BL-500 (particle size: 0.3 to 1.0 μm), or the like can be preferably used. In addition, as octahedral shaped particles, ABL-203 (particle size: 0.4 to 0.5 μm), ABL-204 (particle size: 0.3 to 0.4 μm), ABL-205 (particle size: 0.2 to 0) .3 μm), ABL-207 (particle size 0.2 μm), and the like can be preferably used.

Furthermore, particles whose surface is coated with an inorganic substance such as SiO ₂ can also be preferably used. As such particles, spherical particles coated with SiO ₂ : BL-200 (particle size 0.2 to 0) .3 μm), octahedral shaped particles: ABL-207A (particle size 0.2 μm).

  Specifically, the black composite metal oxide is a composite metal oxide composed of two or more metals selected from Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sb, and Ba. . These are disclosed by methods disclosed in JP-A-8-27393, JP-A-9-25126, JP-A-9-237570, JP-A-9-241529, JP-A-10-231441, and the like. Can be manufactured.

  The composite metal oxide is particularly preferably a Cu-Cr-Mn-based or Cu-Fe-Mn-based composite metal oxide. In the case of a Cu—Cr—Mn system, it is preferable to perform the treatment disclosed in JP-A-8-27393 in order to reduce the elution of hexavalent chromium. These composite metal oxides are colored with respect to the amount added, that is, they have good photothermal conversion efficiency.

  These composite metal oxides preferably have an average primary particle size of 1 μm or less, and more preferably have an average primary particle size in the range of 0.01 to 0.5 μm. When the average primary particle diameter is 1 μm or less, the photothermal conversion ability with respect to the addition amount becomes better, and when the average primary particle diameter is within the range of 0.01 to 0.5 μm, the photothermal conversion ability with respect to the addition amount is obtained. Better.

  However, the photothermal conversion ability with respect to the addition amount is greatly affected by the degree of dispersion of the particles, and the better the dispersion, the better. Therefore, it is preferable to disperse these composite metal oxide particles by a known method separately before adding them to the layer coating solution to prepare a dispersion (paste).

  A dispersing agent can be appropriately used for the dispersion. 0.01-5 mass% is preferable with respect to composite metal oxide particle, and the range of the addition amount of a dispersing agent is more preferable 0.1-2 mass%.

  The range of the content of the photothermal conversion agent in the image forming layer is 1 to 20% by mass, preferably 3 to 15% by mass, and preferably 5 to 12% by mass with respect to the total solid content of the image forming layer. It is more preferable that

  The image forming layer can contain a water-soluble compound (polymer, oligomer, monomer, inorganic salt, organic salt, etc.) other than the above-described phosphobetaine compound. Moreover, additives, such as a pH adjuster, surfactant, and a thickener, can also be contained suitably.

(Water-soluble compounds)
The water-soluble compound refers to a compound that dissolves in an amount of 0.1 g or more in 100 g of water at 25 ° C., and preferably a compound that dissolves in an amount of 1 g or more in 100 g of water at 25 ° C. However, the water-soluble compound used in the present invention excludes the above-mentioned water-soluble phosphate ester compound and the photothermal conversion agent used in the present invention.

  The range of the content of the water-soluble compound in the image forming layer is 1 to 40% by mass, preferably 5 to 30% by mass with respect to the image forming layer in terms of on-press developability and chemical resistance. 10 to 25% by mass is more preferable.

  Specific examples of the water-soluble compound include the following, but are not limited thereto.

  Glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and their ether or ester derivatives, polyhydroxys such as glycerin and pentaerythritol, triethanolamine, diethanolamine monoethanolamine, etc. Organic amines and salts thereof, quaternary ammonium salts such as tetraethylammonium bromide, organic sulfonic acids and salts thereof such as toluenesulfonic acid and benzenesulfonic acid, organic phosphonic acids and salts thereof such as phenylphosphonic acid, tartaric acid and oxalic acid , Organic carboxylic acids such as citric acid, malic acid, lactic acid, gluconic acid, amino acids and salts thereof, phosphates (phosphoric acid tri-Na, hydrogen phosphate di-Na, dihydrogen phosphate Na, Phosphate guanidine), carbonates (carbonate Na, guanidine carbonate), other water-soluble organic salts, inorganic salts. Saccharides (monosaccharides, oligosaccharides, etc.), polysaccharides, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyethylene glycol (PEG), polyvinyl ether, polyacrylic acid, polyacrylate, polyacrylamide, polyvinylpyrrolidone, polystyrene sulfonic acid, Water-soluble polymers such as polystyrene sulfonate are listed. Further, water dispersible latexes such as styrene-butadiene copolymer latex, conjugated diene polymer latex of methyl methacrylate-butadiene copolymer, acrylic polymer latex, and vinyl polymer latex can be exemplified.

  A water-soluble polymerizable compound can also be used. Specifically, the following can be mentioned.

  (Meth) acrylonitrile, (meth) acrylamide, (meth) acrylic acid, sodium (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n -Butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, dimethylamino Ethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, β-ethoxyethyl cellosolve (meth) acrylate, (meth) acrylaldehyde, N, N′-methylenebis (meth) acrylamide, 2-hexyloxy Cyl-N-methacryloylcarbamate, allyl (meth) acrylate, 2-chloroethyl acrylate, 2,2-bis [4- (methacryloxy-polyethoxy) phenyl] propane, diethylene glycol ethoxylate, polyethylene glycol di (meth) ) Acrylate, 3- (meth) acryloilymino-1-phenyl-5-pyrazolone, ω-carboxy-polycaprolactone (n = 2) monoacrylate, monohydroxyethyl phthalate (meth) acrylate, monohydroxyethyl oxalate (meta ) Acrylate, acrylic acid dimer, 2-hydroxy-3-phenoxypropyl acrylate, isocyanuric ethylene oxide (EO) modified diacrylate, pentaerythritol triacrylate, glycerol mono ) Acrylate, glycerol (meth) acrylate, hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether.

  Among the above-mentioned water-soluble compounds, salt compounds such as the above-mentioned organic salts and inorganic salts and water-soluble polymers are preferably used. It is particularly preferable to use a salt compound and a water-soluble polymer in combination.

  The image forming layer may contain a pH adjuster, a surfactant, a thickener and the like in addition to the above components, and may further contain a polymerization initiator. The polymerization initiator is preferably water-soluble or water-dispersible.

  Examples of the water-soluble photopolymerization initiator include (2-acryloyloxy) (4-benzoylbenzyl) dimethylammonium bromide, 2- (3-dimethylamino-2-hydroxypropoxy) -3, 4-dimethyl-9H. -Known examples such as -thioxanthone-9-one mesochloride, (4-benzoylbenzyl) trimethylammonium chloride, 2 (2'-trimethylammoniumethylamino) -4,6-bis (trichloromethyl) -S-triazine As the water-dispersible polymerization initiator, a conventionally known organic solvent-soluble polymerization initiator may be used as an aqueous dispersion using an oil protection dispersion method or the like.

  And as a 1st aspect, it contains a water-soluble phosphobetaine compound in an image formation layer, and contains a water-soluble phosphobetaine compound in 0.1-50 mass% especially in an image formation layer. It is preferable to contain in the range of 0.5-30 mass%. Thus, the object of the present invention can be achieved more suitably.

The dry coating amount of the image forming layer is preferably in the range of 0.05 to 2 g / m ^2, and more preferably in the range of 0.2~1g / m ^2.

  The image forming layer is formed by applying and drying on a support described later. As the coating solvent for the image forming layer, water alone or a mixed solvent of water and an organic solvent is preferably used. As the organic solvent, alcohols, glycols and the like that are miscible with water are preferably used. Specific examples include methanol, ethanol, isopropanol, 1,3-butanediol, 1,2,3-propanetriol, 2-phenoxyethanol, 1,3-butylene glycol and the like.

  As described above, the phosphobetaine compound is considered to have a function of adsorbing the above phosphorylcholine group to the surface of the support. For this reason, when a phosphobetaine compound is contained, it is considered that a thin layer of the phosphobetaine compound is formed at the interface between the image forming layer and the support. This is thought to improve the on-press developability of some parts. Further, since the layer functioning as the release layer is stable to heat, even when kept in a high temperature environment of about 40 to 60 ° C. for 1 to several days, almost no deterioration in on-press developability is observed. .

  By using the phosphobetaine compound, it is possible to obtain good on-press developability even in a region where the content of the water-soluble compound, which will be described later, used for imparting on-press developability is small in the image forming layer. It becomes like this. On the other hand, in the exposed area, there is little inhibition of image formation of a lipophilic image forming material such as thermoplastic particles, microcapsules, and polymerizable compounds described later, and no substantial reduction in sensitivity is observed. In addition, as described above, the water-soluble compound content in the image forming layer can be reduced, and the water-soluble component remaining in the image portion coating film is reduced, so that the image strength and water resistance are improved. As a result, printing durability and chemical resistance are improved.

  As a second aspect, in a printing plate material having an undercoat layer and an image forming layer in this order on a support having a hydrophilic surface, the undercoat layer contains a water-soluble phosphobetaine compound.

  The same effects as described above can also be obtained in an embodiment in which an undercoat layer containing a phosphobetaine compound is provided.

The range of dry coating amount of phosphobetaine compound in the undercoat layer is preferably from ^{1~50mg / m 2, 5~30mg / m} 2 is more preferable.

  The undercoat layer may further contain the above-described water-soluble compound, water-soluble polymerizable compound, polymerization initiator, photothermal conversion agent, and the like.

  Among the water-soluble compounds described above, for example, water-soluble polymers such as polyvinyl alcohol, polyethylene glycol (PEG), polyvinyl ether, polyacrylic acid, polyacrylate, polyacrylamide, polyvinyl pyrrolidone, polystyrene sulfonic acid, polystyrene sulfonate, and the like. Also functions as a binder for the primer layer.

  The undercoat layer can be obtained by applying and drying an undercoat layer coating solution containing the above components on a support. Examples of the coating solvent used in the coating solution for the undercoat layer include water, alcohol, and other organic solvents miscible with water.

(Support)
The support preferably has a hydrophilic surface, and the support having a hydrophilic surface is a base material having a surface that can become a non-image part because the portion from which the thermal image forming layer has been removed becomes water-receptive during printing. A substrate having a hydrophilic surface layer and a substrate provided with a hydrophilic layer containing a hydrophilic substance can be used.

  As the support, a known material used as a substrate of a printing plate can be used. For example, a metal plate, a plastic film, a paper treated with a polyolefin, a composite base material obtained by appropriately bonding the above materials, or the like Is mentioned.

  The thickness of the support is not particularly limited as long as it can be attached to a printing press, but a thickness in the range of 50 to 500 μm is generally easy to handle.

  As the support, a metal plate obtained by hydrophilizing the substrate surface is preferably used.

  Examples of the metal plate include iron, stainless steel, and aluminum. In the present invention, aluminum or an aluminum alloy (hereinafter referred to as an aluminum plate) is particularly preferable because of the relationship between specific gravity and rigidity. Those subjected to any of the known roughening treatment, anodic oxidation treatment, and surface hydrophilization treatment (so-called aluminum grained plate) are more preferred.

  Various aluminum alloys can be used as the base material. For example, an alloy of aluminum such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, titanium, sodium, iron, and the like is used. It is done.

  The aluminum plate used as the substrate is preferably subjected to a degreasing treatment in order to remove the rolling oil on the surface prior to roughening (graining treatment). As the degreasing treatment, a degreasing treatment using a solvent such as trichlene or thinner, an emulsion degreasing treatment using an emulsion such as kesilon or triethanol, or the like is used. In addition, an alkaline aqueous solution such as caustic soda can be used for the degreasing treatment. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, dirt and oxide film that cannot be removed only by the degreasing treatment can be removed. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, smut is generated on the surface of the base material. In this case, it is immersed in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid, or a mixed acid thereof and desmutted. It is preferable to perform the treatment. Examples of the roughening method include a mechanical method and a method of etching by electrolysis.

The mechanical roughening method used is not particularly limited, but a brush polishing method and a honing polishing method are preferable. The roughening by the brush polishing method is performed, for example, by rotating a rotating brush using brush bristles having a diameter of 0.2 to 0.8 mm, and, for example, volcanic ash having a particle diameter of 10 to 100 μm on the substrate surface. While supplying a slurry in which particles are uniformly dispersed in water, the brush can be pressed. The roughening by honing polishing is performed by, for example, uniformly dispersing volcanic ash particles having a particle size in the range of 10 to 100 μm in water, injecting pressure from a nozzle, and causing the substrate surface to collide obliquely. It can be carried out. Further, for example, abrasive particles having a particle size in the range of 10 to 100 μm are formed on the substrate surface at a density in the range of 2.5 × 10 ³ to 10 × 10 ³ particles / cm ² at intervals of 100 to 200 μm. It is also possible to perform roughening by laminating the coated sheets so as to exist and transferring the rough surface pattern of the sheet by applying pressure.

After roughening by the above-mentioned mechanical roughening method, it is preferable to immerse in an aqueous solution of acid or alkali in order to remove the abrasive that has digged into the surface of the base material, formed aluminum scraps, and the like. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like. Examples of the base include sodium hydroxide and potassium hydroxide. Among these, it is preferable to use an aqueous alkali solution such as sodium hydroxide. The dissolution amount of aluminum in the support surface, 0.5 to 5 g / m ² is preferred. After the immersion treatment with an alkaline aqueous solution, it is preferable to carry out a neutralization treatment by immersion in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid or a mixed acid thereof.

The electrochemical surface roughening method is not particularly limited, but a method of electrochemical surface roughening in an acidic electrolyte is preferable. As the acidic electrolytic solution, an acidic electrolytic solution usually used in an electrochemical surface roughening method can be used, but a hydrochloric acid-based or nitric acid-based electrolytic solution is preferably used. As the electrochemical surface roughening method, for example, methods described in Japanese Patent Publication No. 48-28123, British Patent No. 896,563 and Japanese Patent Laid-Open No. 53-67507 can be used. This roughening method can be generally performed by applying a voltage in the range of 1 to 50 volts, but is preferably selected from the range of 10 to 30 volts. Current density may be in the range of 10 to 200 A / dm ^2, preferably selected from the range of 50 to 150 A / dm ^2. The quantity of electricity, may be in the range of 5000 C / dm ^2, preferably selected from the range of 100~2000C / dm ^2. The temperature at which the roughening method is performed can be in the range of 10 to 50 ° C, but is preferably selected from the range of 15 to 45 ° C.

When electrochemical surface roughening is performed using a nitric acid-based electrolyte as the electrolyte, it can be generally performed by applying a voltage in the range of 1 to 50 volts, but is selected from the range of 10 to 30 volts. Is preferred. Current density may be in the range of 10 to 200 A / dm ^2, preferably selected from the range of 20 to 100 A / dm ^2. The quantity of electricity, may be in the range of 5000 C / dm ^2, preferably selected from the range of 100~2000C / dm ^2. The temperature at which the electrochemical roughening method is performed can be in the range of 10 to 50 ° C, but is preferably selected from the range of 15 to 45 ° C. The concentration of nitric acid in the electrolytic solution is preferably 0.1 to 5% by mass. If necessary, nitrates, chlorides, amines, aldehydes, phosphoric acid, chromic acid, boric acid, acetic acid, oxalic acid, and the like can be added to the electrolytic solution.

When a hydrochloric acid-based electrolyte is used as the electrolyte, it can be generally applied by applying a voltage in the range of 1 to 50 volts, but is preferably selected from the range of 2 to 30 volts. Current density may be in the range of 10 to 200 A / dm ^2, preferably selected from the range of 50 to 150 A / dm ^2. The quantity of electricity, may be in the range of ^{100~5000C / dm 2, 100~2000C / dm} 2, and more preferably selected from the range of 200~1000C / dm ^2. The temperature at which the electrochemical roughening method is performed can be in the range of 10 to 50 ° C, but is preferably selected from the range of 15 to 45 ° C. The concentration of hydrochloric acid in the electrolytic solution is preferably 0.1 to 5% by mass.

  After the surface is roughened by the electrochemical surface roughening method, it is preferably immersed in an acid or alkali aqueous solution in order to remove aluminum scraps on the surface. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like. Examples of the base include sodium hydroxide and potassium hydroxide.

Among these, it is preferable to use an alkaline aqueous solution. The dissolution amount of aluminum in the support surface, the range of 0.5 to 5 g / m ² is preferred. In addition, it is preferable that after the immersion treatment with an alkaline aqueous solution, neutralization treatment is performed by immersion in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid or a mixed acid thereof.

  The mechanical surface roughening method and the electrochemical surface roughening method may each be used alone for roughing, or the mechanical surface roughening method followed by the electrochemical surface roughening method. You may roughen.

Following the roughening treatment, anodizing treatment is preferably performed. There is no restriction | limiting in particular in the method of the anodizing process which can be used in this invention, A well-known method can be used. By performing the anodizing treatment, an oxide film is formed on the substrate. For the anodizing treatment, a method of electrolyzing an aqueous solution containing sulfuric acid and / or phosphoric acid or the like at a concentration in the range of 10 to 50% as an electrolytic solution in a current density of 1 to 10 A / dm ² is preferably used. Other methods include electrolysis at a high current density in sulfuric acid described in US Pat. No. 1,412,768, and electrolysis using phosphoric acid described in US Pat. No. 3,511,661. And a method using a solution containing one or more of chromic acid, oxalic acid, malonic acid and the like. The formed anodic oxidation coating amount is suitably in the range of 1 to 50 mg / dm ² , preferably in the range of 10 to 40 mg / dm ² . The anodic oxidation coating amount is obtained by, for example, immersing an aluminum plate in a chromic phosphate solution (produced by dissolving 85% phosphoric acid solution: 35 ml, chromium oxide (IV): 20 g in 1 L of water), dissolving the oxide coating, It is calculated | required from the mass change measurement etc. before and after melt | dissolution of the coating.

  The anodized base material may be subjected to a sealing treatment as necessary. These sealing treatments can be performed using known methods such as hot water treatment, boiling water treatment, water vapor treatment, sodium silicate treatment, dichromate aqueous solution treatment, nitrite treatment, and ammonium acetate treatment.

  Further, after these treatments, as a hydrophilization treatment, a water-soluble resin such as polyvinylphosphonic acid, a polymer or copolymer having a sulfonic acid group in the side chain, polyacrylic acid, a water-soluble metal salt ( For example, zinc borate) or a primer coated with a yellow dye, an amine salt or the like is also suitable. Further, a sol-gel treated substrate in which a functional group capable of causing an addition reaction by a radical as disclosed in JP-A No. 5-304358 is covalently used.

  Examples of the plastic film used as the substrate include polyethylene terephthalate, polyethylene naphthalate, polyimide, polyamide, polycarbonate, polysulfone, polyphenylene oxide, cellulose esters, and the like.

  In the present invention, it is preferable to use an aluminum grain.

<Processless on-machine development>
(exposure)
In the present invention, the printing plate material preferably forms an image using laser light.

  Among these, it is particularly preferable to form an image by exposure with a thermal laser.

  For example, scanning exposure using a laser that emits light in the infrared and / or near infrared region, that is, emits light in the wavelength range of 700 to 1500 nm is preferable.

  A gas laser may be used as the laser, but it is particularly preferable to use a semiconductor laser that emits light in the near infrared region.

  As an apparatus suitable for scanning exposure, any apparatus may be used as long as it can form an image on the surface of a printing plate material in accordance with an image signal from a computer using the semiconductor laser.

  In general, (1) a printing plate material held by a flat plate holding mechanism is exposed two-dimensionally using one or a plurality of laser beams to expose the entire surface of the printing plate material. ) The printing plate material held along the cylindrical surface inside the fixed cylindrical holding mechanism is used in the circumferential direction of the cylinder (main scanning direction) using one or more laser beams from inside the cylinder. A method in which the entire surface of the printing plate material is exposed by moving in a direction perpendicular to the circumferential direction (sub-scanning direction) while scanning, and (3) printing held on the surface of a cylindrical drum that rotates about an axis as a rotating body The plate material is printed by moving in the direction perpendicular to the circumferential direction (sub-scanning direction) while scanning in the circumferential direction (main scanning direction) by rotating the drum using one or multiple laser beams from the outside of the cylinder. A method that exposes the entire plate material That. In particular, in an apparatus that performs exposure on a printing apparatus, the exposure method (3) is used.

(printing)
The image-exposed printing plate material can be subjected to general lithographic printing using dampening water and printing ink.

  As a printing method, it is particularly preferable to use a fountain solution that does not contain isopronol as the fountain solution (the content is not more than 0.5% by mass with respect to water).

  In the present invention, the printing plate material is subjected to image exposure with an infrared laser, and is subjected to on-press development with dampening water or dampening water and printing ink on a printing press for printing.

  The printing plate material after image formation is directly attached to the plate cylinder of the printing press, or the image forming is performed after the printing plate material is attached to the plate cylinder of the printing press, and the water supply roller and / or ink supply is performed while rotating the plate cylinder. By bringing the roller into contact with the printing plate material, it is possible to remove the non-image portion of the thermal image forming layer.

  The removal of the non-image area, a so-called on-press development method will be described below.

  The removal of the non-image part (unexposed part) of the heat-sensitive image forming layer on the printing press can be carried out by contacting a watering roller or an ink roller while rotating the plate cylinder, as in the following examples: Alternatively, it can be performed by various other sequences.

  In that case, the water amount may be adjusted by increasing or decreasing the amount of dampening water required for printing, and the water amount adjustment may be divided into multiple stages or steplessly. You may change it to.

  (1) As a sequence for starting printing, a watering roller is brought into contact with the plate cylinder to make one to several dozen rotations, then an ink roller is brought into contact with the plate cylinder to make one to several dozen rotations, and then Start printing.

  (2) As a sequence for starting printing, an ink roller is contacted to rotate the plate cylinder 1 to several tens of turns, then a watering roller is contacted to rotate the plate cylinder 1 to tens of rotations, Start printing.

  (3) As a sequence for starting printing, the watering roller and the ink roller are brought into contact with each other substantially simultaneously to rotate the plate cylinder 1 to several tens of times, and then printing is started.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. In addition, unless otherwise indicated, "part" in an Example shows a "mass part".

Example 1
<Preparation of fountain solution composition>
According to the composition of Table 1 below, Various fountain solution compositions 1 to 6 were prepared. The balance of the composition was water and finally 1000 ml. The unit of content of each component in the composition is primary ammonium phosphate, ammonium acetate, secondary ammonium citrate and the sum of these in moles / liter, the others are grams. These are all concentrated types and are diluted at the time of use.

  Each of the above fountain solution compositions is diluted 40-fold with water, and NaOH (5 (mol / liter) concentration aqueous solution) and phosphoric acid (85 mass) so that the pH is around 4.8 to 5.3. % Aqueous solution) to prepare a dampening solution that is actually used. These fountain solutions were subjected to the following tests.

<Preparation of lithographic printing plate material>
A planographic printing plate material was prepared by the method of Example 1 of JP-A-2005-148196.

<Evaluation methods>
The above-described lithographic printing plate material (produced by the method of JP-A-2005-148196, Example 1) is 2400 dpi (dpi represents the number of dots per 2.54) using a processor manufactured by Heidelberg. ), Pattern exposure of 0%, 30% and 100% of the 175 line was performed. After exposure at an exposure energy of 45 μJ / cm ² , with a printing press (DAIYA 1F-1 manufactured by Mitsubishi Heavy Industries, Ltd.), coated paper, printing ink (soybean oil ink “Naturalis manufactured by Dainippon Ink and Chemicals, Inc.” 100 ") and the fountain solution described above were printed and evaluated as follows.

(A) Continuous printing stability:
Obtain the amount of dampening water (minimum water raising amount) that does not cause stains and does not cause water loss, and according to the following evaluation criteria according to the number of prints until good prints are not obtained due to occurrence of stains or water loss judge.

○: 10,000 sheets or more Δ: 9999 to 3000 sheets or more ×: 2999 sheets or less (b) Aging property:
The fountain solution after printing 10,000 sheets is collected and allowed to elapse for 3 days at 35 ° C., then set again on the water supply tray of the printing press, and the same evaluation as in (a) above is repeated. As in (a), the amount of dampening water that does not cause stains and does not cause water loss (minimum water raising amount) is obtained, and until a good printed matter cannot be obtained due to occurrence of stains on the printed matter or water loss. Judgment is made according to the following evaluation criteria by the number of printed sheets.

○: 10,000 sheets or more Δ: 9999 to 3000 sheets or more ×: 2999 sheets or less (c) Image portion deterioration Stop the printing machine, and use a syringe for the solid portion of the planographic printing plate and the image portion of the 30% halftone dot portion, 5 μl, 10 μl, 20 μl and 50 μl of each fountain solution are added dropwise and left for 60 minutes. Thereafter, printing is resumed, the image area is visually observed for deterioration, and evaluated according to the following evaluation criteria.

○: No problem △: Slightly deteriorated (with ring marks)
X: Unusable due to image region deterioration The results are shown in Table 1 below.

  From Table 1, it can be seen that the fountain solution according to the example of the present invention is excellent in all of the continuous printing stability, aging property and image portion deterioration, and a good printed matter can be obtained. Further, the fountain solution compositions of Examples 1 to 7 are different from isopropyl alcohol, have no problems in terms of occupational safety and fire safety, and are organic solvents that are included in existing isopropyl alcohol alternative fountain solutions. Is not used, and the amount of the volatile organic solvent can be extremely reduced, which is very preferable from the viewpoint of the environment.

Example 2
A support was prepared as follows.

[Support]
An aluminum plate (material 1050, tempered H16) having a thickness of 0.24 mm was immersed in a 1% by mass sodium hydroxide aqueous solution at 50 ° C., dissolved so that the dissolved amount became 2 g / m ² , and washed with water. Then, it was immersed in 5 mass% nitric acid aqueous solution at 25 ° C. for 30 seconds, neutralized, and then washed with water.

Next, the aluminum plate was subjected to electrolytic surface roughening with an electrolytic solution containing hydrochloric acid 11 g / L, acetic acid 10 g / L, and aluminum 8 g / L using a sinusoidal alternating current at a peak current density of 80 A / dm ^2. Processed. The distance between the electrode and the sample surface at this time was 10 mm. Electrolytic surface-roughening treatment was performed by dividing into 8 times, and the quantity of electricity used in one treatment (the anode time) the 40C / dm ^2, treatment quantity of electricity Total (anode) and 320C / dm ^2. In addition, a pause time of 3 seconds was provided between each treatment.

After electrolytic surface roughening, it is immersed in a 10% by mass phosphoric acid aqueous solution maintained at 50 ° C. and etched so that the amount of dissolution including the smut of the roughened surface becomes 0.65 g / m ^2. , Washed with water.

Next, an anodizing treatment was performed in a 20% sulfuric acid aqueous solution under the condition that an anodic oxide film having a weight of 2.5 g / m ² was formed at a current density of 5 A / dm ² and further washed with water.

  Next, after squeezing the surface water after washing with water, it was immersed in a 0.5% by weight aqueous solution of dihydrogen hydrogen phosphate kept at 70 ° C. for 15 seconds, washed with water, dried at 80 ° C. for 5 minutes, and supported. Body 2 was obtained.

  The surface shape parameter Ra value of the support was determined by the following method. The Ra value was 0.38 μm.

[Measurement method of surface shape parameter of support]
After depositing platinum rhodium with a thickness of 1.5 nm on the surface of the sample, using a non-contact three-dimensional roughness measuring apparatus manufactured by WYKO: RST plus, a 40-fold condition (111.2 μm × 149.7 μm measurement) The measurement point was 236 × 368 and the resolution was about 0.5 μm within the range, and the measurement data was processed by applying inclination correction and a media smoothing filter to remove noise, and then the Ra value was obtained. The measurement was performed 5 times while changing the measurement location, and the average was obtained.

The following undercoat layer coating solution B is applied to the surface obtained as described above using a wire bar so that the dry weight is 15 mg / m ^2, and dried at 100 ° C. for 1 minute. A support having a layer was obtained.

Undercoat layer coating solution B
Phosphobetaine compound [2] (supra) 0.15 parts Pure water 99.85 parts [Hydrophilic layer]
A material having the following composition was sufficiently stirred and mixed using a homogenizer and then filtered to prepare a hydrophilic layer coating solution having a solid content of 15% by mass.

On the roughened aluminum plate, a hydrophilic layer coating solution is applied using a wire bar so that the applied amount after drying is 2.5 g / m ² and dried at 110 ° C. for 3 minutes. Thus, a hydrophilic layer was produced.

(Hydrophilic layer coating composition)
Hydrophilic layer colloidal silica (alkaline): Snowtex-S (Nissan Chemical Co., Ltd.)
(Solid content 30.0%) 3.33 parts Necklace-shaped colloidal silica (alkaline): Snowtex-PSM
(Nissan Chemical Co., Ltd.) (solid content 20.0%) 7.50 parts lithium silicate 35
(Nissan Chemical Co., Ltd., solid content 20.0% as amorphous silica) 3.00 parts Layered mineral particles Montmorillonite: Mineral colloid MO (Southern Cray Products, average particle size 0.1 μm) was vigorously stirred with a homogenizer to obtain 5 2.00 parts of low-magnetization amount black pigment: ETB-300 (manufactured by Titanium Industry Co., Ltd.) 4.79 parts of trisodium phosphate.12 water (reagent manufactured by Kanto Chemical Co., Inc.) 0% by weight aqueous solution
0.10 parts Porous metal oxide particle silton AMT08 (manufactured by Mizusawa Chemical Co., Ltd., porous aluminosilicate particles, average particle size 0.6 μm) 1.50 parts Porous metal oxide particle Shilton JC-30 (manufactured by Mizusawa Chemical Co., Ltd.) , Porous aluminosilicate particles, average particle size 3 μm) 0.50 parts Pure water 7.28 parts [Preparation of coating solution for image forming layer]
The materials shown in the table below were sufficiently mixed and stirred and filtered to prepare an image forming layer coating solution having a solid content concentration of 5% by mass. As the order of addition of the raw materials, pure water was added to the aqueous dispersion of thermoplastic resin particles, and then the aqueous water-soluble compound solution was dropped and mixed while stirring this. Next, when it contained a water-soluble phosphate ester compound, the aqueous solution was dropped and mixed, and when it contained other additives, this was added and mixed. Finally, an aqueous solution of the compound having plasmon absorption of the present invention that absorbs an infrared dye and is a photothermal conversion agent and a comparative cyanine dye were dropped and mixed.

(Image forming layer coating solution composition (numbers in the table represent parts by mass))
Thermoplastic resin particles: Styrene acrylic particle dispersion (average particle size 80 nm, Tg 100 ° C., solid content 40% by mass, pH 8 solvent composition: water / IPA = 90/10) 8.75 parts Cyanine dye aqueous solution (solid content 1% ) 50 parts Water-soluble compound (Mass ratio of aqueous solution of a mixture of polyacrylic acid (Mw 2.5 million) and tri-Na phosphate 12 hydrate: 20/80, solid content 10% by mass) 8.50 parts Phosphobetaine compound [ 2] (supra) 0.15 parts pure water 32.60 parts

[Preparation of planographic printing plate material 2-1]
The image forming layer coating solution was applied onto the support using a wire bar so that the dry weight was 0.5 g / m ² and dried at 55 ° C. for 3 minutes. Next, this was subjected to an aging treatment at 40 ° C. for 24 hours to prepare a lithographic printing plate material 2-1.

[Exposure with infrared laser]
The lithographic printing plate material was wound around the exposure drum and fixed. A laser beam having a wavelength of 830 nm and a spot diameter of about 18 μm was used for exposure, and an image was formed with 2400 dpi (dpi represents the number of dots per 2.54 cm) and 175 lines. The exposed image includes a solid image and a 1 to 99% halftone dot image. The exposure energy was 120 mJ / cm ² .

[On-press development and printing evaluation]
Printing machine: DAIYA1F-1 manufactured by Mitsubishi Heavy Industries, Ltd. Coated paper, dampening water: lithographic printing after exposure using dampening water and ink (TK High Unity MZ Red, manufactured by Toyo Ink Co., Ltd.) The plate material was directly attached to the plate cylinder, 30 sheets were printed using the same printing conditions and printing sequence as the PS plate, and development processing was performed on the printing press. Thereafter, printing evaluation was performed in the same manner as in Example 1.

  The results are shown in Table 2 below.

  From Table 2, it can be seen that the fountain solution according to the examples of the present invention is excellent in continuous printing stability, aging, and image portion deterioration, and a good printed matter can be obtained. Further, the fountain solution compositions of Examples 1 to 7 are different from isopropyl alcohol, have no problems in terms of occupational safety and fire safety, and are organic solvents that are included in existing isopropyl alcohol alternative fountain solutions. Is not used, and the amount of the volatile organic solvent can be extremely reduced, which is very preferable from the viewpoint of the environment.

[Preparation of planographic printing plate material 2-2]
In the production of the lithographic printing plate material 2-1, the lithographic printing plate material 2-1 was prepared except that an undercoat layer was not applied and the water-soluble phosphate compound (2) was not added to the image forming layer. In the same manner as above, a planographic printing plate material 2-2 was produced.

  Two types of lithographic printing plate materials 2-1 and 2-2 are prepared: one that is evaluated as it is after aging treatment, and one that is evaluated after heat storage processing at 55 ° C. for 48 hours. The following evaluation was performed.

[Exposure with infrared laser]
The lithographic printing plate material was wound around the exposure drum and fixed. A laser beam having a wavelength of 830 nm and a spot diameter of about 18 μm was used for exposure, and an image was formed with 2400 dpi (dpi represents the number of dots per 2.54 cm) and 175 lines. The exposed image includes a solid image and a 1 to 99% halftone dot image. The exposure energy was 120 mJ / cm ² .

[On-press development and printing evaluation]
Printing machine: DAIYA1F-1 manufactured by Mitsubishi Heavy Industries, Ltd. Coated paper, dampening water: lithographic printing after exposure using dampening water and ink shown in Table 3 (TK High Unity MZ Red manufactured by Toyo Ink Co., Ltd.) The plate material was directly attached to the plate cylinder, 500 sheets were printed using the same printing conditions and printing sequence as the PS plate, and development processing was performed on the printing press.

  Next, the printing paper was changed to high-quality paper (Shiraoi), and printing was performed up to 20,000 sheets.

[Evaluation of on-press developability]
The number of printed materials obtained from printing was determined to obtain a good image. A good image has no background stain, 90% halftone dot images are open, and the density of the solid image portion is 1.5 or more. When a good image was not obtained even after printing 500 coated papers, the number was 500 or more.

[Evaluation of printing durability]
The printed matter was sampled every 1000 prints, and the degree of image deterioration in the 3% halftone dot image portion and the solid image portion was confirmed. The point in time when missing halftone dots were confirmed in the 3% halftone image portion, or the point where blurring was visually confirmed in the solid image portion was defined as the printing end point, and the number of printed sheets was defined as the number of printed sheets. Even after 20,000 sheets were printed, 3% halftone dot images were missing or solid images were not confirmed to be 20,000 sheets or more.

[Evaluation of chemical resistance]
500 sheets were printed using coated paper in the same manner as described above. The plate surface after printing was uniformly applied to the plate surface with a sponge containing an ultra plate cleaner (manufactured by SK Liquid Manufacturing Co., Ltd.). After maintaining for 2 minutes in this state, the plate surface cleaner was wiped off with a sponge wrung out of water. Next, another 100 sheets are printed, and the prints of the 500th sheet and the 600th sheet are compared, and the degree of deterioration of the image (10 to 50% halftone dot image portion and solid image portion) before and after the cleaning process. Was visually evaluated using the following indices.
◯: Degradation of the image is hardly seen Δ: Degradation is seen in the 10% to 50% halftone image part ×: Degradation is seen in the solid image part Table 3 shows the results.

  From Table 3, when the fountain solution of the present invention is used, the printing plate material has good on-press developability after heat preservation treatment, and is excellent in printing durability and chemical resistance. Recognize.

The fountain solution composition for lithographic printing of the present invention is good even after the heat preservation treatment of the lithographic printing plate material of the on-press development CTP, which is a heat-bonding hydrophobized (thermoplastic hydrophobic resin fine particle) type. It can be seen that it is suitable for on-press development CTP because it has excellent on-press developability and is difficult to cause stains on the unexposed portion of the printed matter. (In addition, it was excellent in printing durability and chemical resistance.)
Example 3
(Production of support)
In order to remove rolling oil on the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm, a degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution. The aluminum surface was grained using three bundle-planted nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm and washed thoroughly with water. This plate was etched by being immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C for 9 seconds, washed with water, further immersed in 20 mass% nitric acid at 60 ° C for 20 seconds, and washed with water. The etching amount of the grained surface at this time was about 3 g / m ² .

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

Next, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an anode In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying. The plate was provided with a DC anodized film of 2.5 g / m ² at a current density of 15 A / dm ² using 15% by mass sulfuric acid (containing 0.5% by mass of aluminum ions) as an electrolytic solution, then washed with water and dried.

  Next, it processed for 10 second at 30 degreeC with 2.5 mass% sodium silicate aqueous solution. 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.

Furthermore, the following undercoat liquid (1) was applied so that the dry coating amount was 10 mg / m ² to prepare a support used in the following experiments.

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

[Preparation of lithographic printing plate materials]
(1) Production of lithographic printing plate material (1) An image recording layer coating solution (1) having the following composition was bar-coated on the support, and then oven-dried at 100 ° C for 60 seconds to obtain a dry coating amount of 1. An image recording layer of 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 microcapsule solution (1) immediately before coating.

Photosensitive solution (1)
・ The following binder polymer (1) 0.162 g
-0.1 g of the following polymerization initiator (1)
・ The following infrared absorber (1) 0.020 g
・ Polymerizable compound (Aronix M215, manufactured by Toagosei Co., Ltd.) 0.385 g
-0.044 g of the following fluorosurfactant (1)
・ Methyl ethyl ketone 1.091g
・ 1-methoxy-2-propanol 8.609g
Microcapsule liquid (1)
・ Microcapsule synthesized as follows (1) 2.640 g
・ Water 2.425g

(Synthesis of microcapsule (1))
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemical Co., Ltd., Takenate D-110N) 10 g, pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., SR444) 3.15 g, Infrared absorber (2) 0.35 g, 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane (ODB manufactured by Yamamoto Kasei Co., Ltd.) 1 g, and pionine A-41C (Takemoto) 0.1 g of Oil (fat) was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12,000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 3 hours. The microcapsule solution thus obtained was diluted with distilled water so that the solid content concentration was 15% by mass. The average particle size was 0.2 μm.

(Formation of protective layer)
A protective layer coating solution (1) having the following composition was further bar-coated on the image recording layer, followed by oven drying at 100 ° C. for 75 seconds to form a protective layer having a dry coating amount of 1 g / m ² and lithographic printing. A plate material (301) was obtained.

Protective layer coating solution (1)
・ Polyvinyl alcohol (Poval PVA105) 0.895g
(Kuraray Co., Ltd., saponification degree 98-99 mol%, polymerization degree 500)
・ Polyvinylpyrrolidone (K30) 0.035g
(Wako Pure Chemical Industries, Ltd., weight average molecular weight 400,000)
・ Nonionic surfactant 0.020g
(Product name: EMALEX 710, manufactured by Nippon Emulsion Co., Ltd.)
・ P-toluenesulfonic acid 0.100 g
・ Water 16.200g
[Exposure with infrared laser]
The lithographic printing plate material was wound around the exposure drum and fixed. A laser beam having a wavelength of 830 nm and a spot diameter of about 18 μm was used for exposure, and an image was formed with 2400 dpi (dpi represents the number of dots per 2.54 cm) and 175 lines. The exposed image includes a solid image and a 1 to 99% halftone dot image. The exposure energy was 120 mJ / cm ² .

[On-press development and printing evaluation]
Printing machine: using DAIYA1F-1 manufactured by Mitsubishi Heavy Industries, Ltd., using coated paper, dampening water (dampening water listed in Table 4), ink (TK High Unity MZ Red manufactured by Toyo Ink Co., Ltd.), and after exposure The planographic printing plate material was directly attached to the plate cylinder, 30 sheets were printed using the same printing conditions and printing sequence as the PS plate, and development processing was performed on the printing press. Thereafter, in the same manner as in Example 1, no. Printing evaluation of 301 to 304 was performed.

  The results are shown in Table 4 below.

  As is apparent from Table 4, the fountain solution composition for lithographic printing according to the present invention has good on-press development even in the case of a lithographic printing plate material for on-press development CTP of the photothermal polymerization (microcapsule) type. It can be seen that it is suitable for on-press development CTP because it is less likely to cause stains in the unexposed areas of the printed matter.

  As is apparent from Examples 1-3 above, the present invention has good on-press developability and good on-press developability for lithographic printing plate materials after high-temperature storage. It can be seen that a fountain solution for lithographic printing suitable for on-press development CTP and an image forming method can be provided.

  It is also effective in dampening water that does not contain organic solvents such as isopropanol, is stable with little change due to evaporation of organic solvents, has good on-machine developability that can avoid VOC and flammability problems. It can be seen that a fountain solution for lithographic printing suitable for on-press development CTP and an image forming method can be provided.

Claims (4)

  A fountain solution composition for lithographic printing comprising a water-soluble phosphobetaine compound.   The fountain solution for lithographic printing according to claim 1, wherein the water-soluble phosphobetaine compound is a compound having a phosphorylcholine group.   The fountain solution composition for lithographic printing according to claim 1 or 2, which is substantially free of a volatile organic solvent.   After image exposure of the lithographic printing plate material, the lithographic printing dampening solution according to any one of claims 1 to 3 is used to convert the lithographic printing plate material into a lithographic printing plate on a printing press. An image forming method, wherein the image is developed and then printed.