JP2008033087A - Photosensitive lithographic printing plate material and method for producing lithographic printing plate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive lithographic printing plate material having high sensitivity and free of staining of a non-image area even by development at low pH, and a method for producing a lithographic printing plate using the same. <P>SOLUTION: The photosensitive lithographic printing plate material has a photosensitive layer containing a spectral sensitizer, a polymerization initiator, a coinitiator, a polymerizable monomer and a polymer binder on a support and an oxygen blocking layer containing polyvinyl alcohol on the photosensitive layer, wherein the photosensitive layer contains a hexaarylbisimidazole compound as the polymerization initiator and a mercapto compound of a specific structure as the coinitiator. When a lithographic printing plate is produced, the unexposed part of the photosensitive layer after recording image information by exposure with a laser light source having an emission wavelength in a range of 350-450 nm is removed with an aqueous solution containing a water-soluble resin and a surfactant and having pH of 3.0-9.0 at 25°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photosensitive lithographic printing plate used in a so-called computer-to-plate (hereinafter referred to as “CTP”) system, and particularly to exposure with a laser beam having a wavelength of 350 to 450 nm. The present invention relates to a suitable photosensitive lithographic printing plate material and a method for producing a lithographic printing plate using the same.

  In recent years, digitization technology that electronically processes, stores, and outputs image information using a computer has become widespread, and in printing plate preparation technology for offset printing, directivity is determined according to digitized image information. A so-called CTP system that scans a high laser beam and directly records it on a photosensitive lithographic printing plate has been developed, and its practical application is progressing.

  Among these, in the field of printing that requires a relatively high printing durability, it is known to use a negative photosensitive lithographic printing plate material having a polymerization type photosensitive layer containing a polymerizable compound. (For example, refer to Patent Documents 1 and 2.)

  Light sources such as Ar laser (488 nm) and YD-YAG (532 nm) are known as light sources used for the polymerization type photosensitive layer, but the output is not sufficiently high in plate making using these light sources. Therefore, it is insufficient to increase the productivity of the plate making process, and the workability is insufficient from the viewpoint of the use of the safelight.

  On the other hand, in recent years, lasers capable of continuous transmission within the range of high-power and small-sized shortwave light (wavelength: 350 to 450 nm) have become readily available.

  In order to improve the above-described productivity and safelight properties, printing plate materials suitable for these short-wave lasers have been developed. For example, a printing plate material containing biimidazole in the photosensitive layer is known. Further, as a photopolymerizable composition having high sensitivity and low sublimation, for example, a hexagon containing an aryl group having a substituent such as an alkyl group. A photopolymerizable composition containing an arylbiimidazole compound is known (see, for example, Patent Documents 3 and 4).

  However, these printing plate materials still have problems such as insufficient sensitivity and proper development.

  On the other hand, the photopolymerization type photosensitive lithographic printing plate material is usually subjected to image exposure and, if necessary, heat treatment, followed by washing with water for removing the oxygen blocking layer, and dissolving and removing unexposed portions (non-image portions). Development processing, water washing treatment, and finisher gum treatment for hydrophilizing the non-image area are performed to obtain a lithographic printing plate. In preparing a lithographic printing plate from this photosensitive lithographic printing plate material, in order to completely remove the unexposed photosensitive layer of the photosensitive layer, that is, to perform development, usually, a pH 12. It was common to use 5 or more.

However, in recent years, processing with an alkaline developer having a lower pH has been desired from the viewpoint of workability, safety, environmental suitability, and the like. However, such a relatively low pH developer basically has poor dissolving power of the photosensitive layer, and therefore has problems such as insufficient development and contamination of non-image areas.
JP-A-1-105238 JP-A-2-127404 JP 2001-194882 A JP 2004-137152 A

  SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a photosensitive lithographic printing plate material that is highly sensitive and does not cause stains in non-image areas even when developed at a low pH, and production of a lithographic printing plate using the same. It is an object to provide a method.

  The above-mentioned problem according to the present invention is solved by the following means.

  1. It has a photosensitive layer containing a spectral sensitizer, a polymerization initiator, a co-initiator, a polymerizable monomer, and a polymer binder on the support, and further has an oxygen barrier layer containing polyvinyl alcohol on it. A photosensitive lithographic printing plate material, wherein the photosensitive layer contains a hexaarylbisimidazole compound as a polymerization initiator, a compound represented by the following general formula (1) as a co-initiator, and a lithographic plate When the printing plate is prepared, the unexposed portion after exposing and recording image information with a laser light source having an emission wavelength in the range of 350 nm to 450 nm contains a water-soluble resin and a surfactant and has a temperature of 25 ° C. A photosensitive lithographic printing plate material, which can be removed with an aqueous solution having a pH of 3.0 to 9.0.

[X represents an oxygen atom, —NR ₁ — or selenium, R ₁ represents an alkyl group which may have a substituent, or an aryl group which may have a substituent, and Y represents N═C—X. It represents an atomic group that forms a 5-membered heterocycle with the moiety, and Y may further have a substituent. ]
2. 2. The photosensitive lithographic printing plate material as described in 1 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[R ₁ represents an alkyl group that may have a substituent, or an aryl group that may have a substituent, and R ₂ represents a hydrogen atom, an alkyl group that may have a substituent, or a substituent. Represents an aryl group which may have ]
3. 2. The photosensitive lithographic printing plate material as described in 1 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (3).

[R ₂ represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. ]
4). 2. The photosensitive lithographic printing plate material as described in 1 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (4).

[R ₁ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. ]
5. 2. The photosensitive lithographic printing plate material as described in 1 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (5).

[R ₂ and R ₃ each independently represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. ]
6). 2. The photosensitive lithographic printing plate material as described in 1 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (6).

[R ₁ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. R _{4 to} R ₇ represent a hydrogen atom, a halogen atom, an alkoxyl group, a dialkylamino group, an alkyl group that may have a substituent, or an aryl group that may have a substituent. ]
7). The photosensitive lithographic printing plate material as described in any one of 1 to 6 above, wherein the photosensitive layer contains a polymerizable compound having a hydroxyl group in the molecule as the polymerizable monomer.

  8). 8. The photosensitive lithographic printing plate material as described in any one of 1 to 7, wherein the photosensitive layer contains a homopolymer or copolymer of N-vinylpyrrolidone as the polymer binder.

  9. After exposing and recording image information on the photosensitive lithographic printing material according to any one of 1 to 8 with a laser light source, the plate surface is heated to a temperature of 80 ° C. to 160 ° C., and then water-soluble. A method for preparing a lithographic printing plate, comprising removing an unexposed portion with an aqueous solution containing a functional resin and a surfactant and having a pH of 3.0 to 9.0 at 25 ° C.

  10. After the step of heating so that the temperature of the printing plate is 80 ° C. to 160 ° C., an unexposed portion is formed by an aqueous solution containing a water-soluble resin and a surfactant and having a pH of 3.0 to 9.0 at 25 ° C. 10. The method of preparing a lithographic printing plate as described in 9 above, further comprising a step of removing a part of the oxygen blocking layer and the photosensitive layer by washing with water before the step of removing.

  By the above-mentioned means of the present invention, a photosensitive lithographic printing plate material which is highly sensitive and does not cause stains in non-image areas even by developing at a low pH, and a method for producing a lithographic printing plate using the same Can be provided.

  More specifically, the invention described in claims 1 to 6 can provide a photosensitive lithographic printing plate material that is highly sensitive and that does not cause stains in non-image areas even when developed at low pH. Furthermore, the invention described in claims 7 and 8 can further enhance the suitability for development processing at low pH from the side of the photosensitive lithographic printing plate material itself. Furthermore, according to the ninth and tenth aspects of the invention, from the aspect of the lithographic printing plate production process, it is possible to achieve higher sensitivity and improved development processing suitability, that is, reduction of non-image area stains. I can do it.

  The photosensitive lithographic printing plate material of the present invention has a photosensitive layer containing a spectral sensitizer, a polymerization initiator, a co-initiator, a polymerizable monomer, and a polymer binder on a support, and further thereon. A photosensitive lithographic printing plate material having an oxygen barrier layer containing polyvinyl alcohol, wherein the photosensitive layer contains a hexaarylbisimidazole compound as a polymerization initiator, and is represented by the general formula (1) as a coinitiator In the preparation of a lithographic printing plate, the unexposed portion after exposing and recording image information with a laser light source having a light emission wavelength in the range of 350 nm to 450 nm contains a water-soluble resin and a compound represented by It can be removed by an aqueous solution containing a surfactant and having a pH of 3.0 to 9.0 at 25 ° C. The method for producing a lithographic printing plate according to the present invention is characterized in that it utilizes the technical characteristics of the photosensitive lithographic printing plate material and is a method suitable for achieving the above-described solution at a higher level. .

  The “unexposed portion” after image information is exposed and recorded by a laser light source is a portion of the entire photosensitive layer where the laser beam does not substantially reach and no photochemical or physicochemical change occurs, That is, it refers to a so-called “non-image portion”.

  Hereinafter, the present invention and its components will be described in detail.

(Co-initiator: compound represented by general formula (1))
The photosensitive lithographic printing plate material of the present invention is characterized in that the photosensitive layer contains a compound represented by the general formula (1) as a coinitiator.

  Here, the “co-initiator” refers to a compound having a function of promoting a polymerization reaction that proceeds with the reaction of a polymerization initiator described later.

  More specifically, the compound represented by the general formula (1) as the coinitiator according to the present invention is preferably a compound represented by the general formulas (2) to (6).

In the general formulas (1) to (6), X represents an oxygen atom, —NR ₁ —, or selenium, Y represents an atomic group that forms a 5-membered heterocycle with the N═C—X moiety, You may have a substituent.

R _{1 to} R ₃ represent an alkyl group which may have a substituent or an aryl group which may have a substituent.

R _{4 to} R ₇ represent a hydrogen atom, a halogen atom, an alkoxyl group, a dialkylamino group, an alkyl group that may have a substituent, or an aryl group that may have a substituent.

  The alkyl group which may have the above substituent is not particularly limited, but is methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group. N-pentyl group, n-hexyl group, cyclohexyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group and other linear, branched, and cyclic alkyl groups, and those having any substituents are examples. As mentioned. The substituents that can be substituted on these alkyl groups are not particularly limited, and examples thereof include alkyl groups, alkoxy groups, alkylamino groups, dialkylamino groups, halogens, aryl groups, and aralkyl groups.

  Preferable examples include methyl group, ethyl group, n-butyl group, t-butyl group, methoxymethyl group, methoxyethyl group, benzyl group, chloromethyl group and the like.

Examples of the aryl group that may have the above-described substituent include a phenyl group, a naphthyl group, and those having an arbitrary substituent on them. The substituent that can be substituted on the aryl group is not particularly limited, and examples thereof include an alkyl group, an alkoxy group, an alkylamino group, a dialkylamino group, a halogen, an aryl group, and an aralkyl group.
Preferable examples include phenyl group, tolyl group, methoxyphenyl group, chlorophenyl group, t-butylphenyl group, dialkylaminophenyl group and the like.

  Specific examples of the compounds represented by the general formulas (1) to (6) are given below, but are not limited thereto.

  The amount of the compounds represented by the general formulas (1) to (6) is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, based on the total solid content of the photosensitive layer. %. More preferably, it is 1.0-10 mass%.

  In the present invention, various co-initiators conventionally known in the technical field according to the present invention, for example, co-initiators disclosed in JP-A-8-254821 and JP-A-2005-062482 are used in combination. You can also.

(Aqueous solution for removing unexposed areas)
The photosensitive lithographic printing plate material of the present invention has an unexposed portion (non-image portion) after exposing and recording image information with a laser light source having a light emission wavelength in the range of 350 nm to 450 nm when preparing a lithographic printing plate. It can be removed with an aqueous solution containing a water-soluble resin and a surfactant and having a pH at a temperature of 25 ° C. in the range of 3.0 to 9.0.

  Examples of the water-soluble resin according to the present invention include gum arabic, fiber derivatives (for example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose and the like) and modified products thereof, polyvinyl alcohol and derivatives thereof, polyvinylpyrrolidone, polyacrylamide and copolymers thereof. Vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, styrene / maleic anhydride copolymer, and the like. The content of these water-soluble resins is suitably 0.1 to 50% by mass, more preferably 0.5 to 3.0% by mass in the composition.

  In addition, examples of the surfactant according to the present invention include an anionic surfactant and a nonionic surfactant. For example, anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinates, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfones. Acid salts, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, polyoxyethylene aryl ether sulfonates, polyoxyethylene naphthyl ether sulfonates, N-methyl-N-oleyl taurine sodium salts N-alkylsulfosuccinic acid monoamido disodium salts, petroleum sulfonates, nitrated castor oil, sulfated beef tallow oil, sulfate esters of fatty acid alkyl esters, Rualkyl nitrates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphate esters, polyoxyethylene alkyl ethers Phosphate ester salts, polyoxyethylene alkylphenyl ether phosphate ester salts, partially saponified products of styrene-maleic anhydride copolymer, partially saponified products of olefin-maleic anhydride copolymer, naphthalenesulfonate formalin condensates Etc. Among these, dialkyl sulfosuccinates, alkyl sulfate esters, and alkyl naphthalene sulfonates are particularly preferably used.

  Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene aryl ethers, polyoxyethylene naphthyl ether, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxy Propylene alkyl ether, glycerin fatty acid partial ester, sorbitan fatty acid partial ester, pentaerythritol fatty acid partial ester, propylene glycol mono fatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid moiety Esters, polyethylene glycol fatty acid esters, polyglycerol fatty acid partial esters, polyoxyethylenated ester List oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides, etc. It is done. Of these, polyoxyethylene alkylphenyl ethers, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene-polyoxypropylene block polymers and the like are preferably used. Fluorine-based and silicon-based anions and nonionic surfactants can also be used.

  Examples of preferable surfactants include surfactants added to the lithographic printing plate surface protective agents described in JP-A Nos. 2004-167903, 2004-230650, and 2005-43393. .

  Two or more of these surfactants can be used in combination. For example, two or more different from each other can be used in combination. For example, a combination of two or more different anionic surfactants or a combination of an anionic surfactant and a nonionic surfactant is preferable. Although the usage-amount of the said surfactant does not need to specifically limit, Preferably it is 0.01-20 mass% of a post-processing liquid.

  The pH of the aqueous solution according to the present invention can be used in the range of 3.0 to 9.0. When using in the acidic range pH 3-6, it adjusts by adding a mineral acid, an organic acid, an inorganic salt, etc. in aqueous solution. The addition amount is preferably 0.01 to 2% by mass. Examples of mineral acids include nitric acid, sulfuric acid, phosphoric acid, and metaphosphoric acid.

  Examples of the organic acid include citric acid, acetic acid, succinic acid, malonic acid, p-toluenesulfonic acid, tartaric acid, malic acid, lactic acid, levulinic acid, phytic acid, and organic phosphonic acid.

Further, examples of the inorganic salt include magnesium nitrate, primary sodium phosphate, secondary sodium phosphate, nickel sulfate, sodium hexamethanoate, sodium tripolyphosphate, and the like. You may use together at least 1 sort (s) or 2 or more types, such as a mineral acid, an organic acid, or an inorganic salt.
When used in the basic region pH 8 to 9, it can be adjusted to the pH by adding a water-soluble organic base or inorganic base. A water-soluble organic base is preferable, and examples include triethanolamine, diethanolamine, and ethanolamine.

  Moreover, antiseptic | preservative, an antifoamer, etc. can be added to the aqueous solution which concerns on this invention.

  For example, as a preservative, phenol or a derivative thereof, o-phenylphenol, p-chlorometacresol, hydroxybenzoic acid alkyl ester, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, benzoisothiazoline-3- ON, benztriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, derivatives of pyridine, quinoline, guanidine, diazine, triazole derivatives, oxazole, oxazine derivatives and the like. A preferable addition amount is an amount that exerts a stable effect on bacteria, molds, yeasts, etc., and varies depending on the type of bacteria, molds, yeasts, but 0.01% with respect to the plate surface protective agent at the time of use. The range of ˜4% by mass is preferable, and it is preferable to use two or more kinds of preservatives in combination so as to be effective against various molds and sterilization. As the antifoaming agent, a silicon antifoaming agent is preferable. Among them, emulsification dispersion type and solubilization can be used. Preferably the range of 0.01-1.0 mass% is optimal.

  Further, a chelate compound may be added. Preferred chelate compounds include, for example, ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, sodium salt thereof; ethylenediamine disuccinic acid, potassium salt thereof. Triethylenetetramine hexaacetic acid, potassium salt thereof, sodium salt thereof, hydroxyethylethylenediaminetriacetic acid, potassium salt thereof, sodium salt thereof: nitrilotriacetic acid, sodium salt thereof; 1-hydroxyethane-1,1-diphosphone Acids, potassium salts, sodium salts; organic phosphonic acids or phosphonoalkanetricarboxylic acids such as aminotri (methylenephosphonic acid), potassium salts, sodium salts, etc. It can be mentioned.

  An organic amine salt is also effective in place of the sodium salt and potassium salt of the chelating agent. These chelating agents are selected so that they are stably present in the gum solution composition and do not impair the printability. The addition amount is suitably 0.001 to 1.0% by mass.

  In addition to the above components, a sensitizer can be added as necessary. For example, hydrocarbons such as turpentine oil, xylene, toluene, low heptane, solvent naphtha, kerosene, mineral spirit, petroleum fraction having a boiling point of about 120 ° C to about 250 ° C, such as dibutyl phthalate, dihebutyl phthalate, di-n-octyl Phthalic acid diester agents such as phthalate, di (2-ethylhexyl) phthalate, dinonyl phthalate, didecyl phthalate, dilauryl phthalate, butyl benzyl phthalate, such as dioctyl adipate, butyl glycol adipate, dioctyl azelate, dibutyl sebacate, di ( 2-ethylhexyl) aliphatic dibasic acid esters such as sebacate and dioctyl sebacate, epoxidized triglycerides such as epoxidized soybean oil, such as tricresyl phosphate, trioctylfolate Feto, phosphoric acid esters such as tris chloroethyl phosphate, for example, freezing point, such as benzoic acid esters of benzyl benzoate and at 15 ℃ below boiling point at one atmosphere include 300 ° C. or more plasticizers.

  Furthermore, caproic acid, enanthic acid, caprylic acid, helargonic acid, capric acid, undecyl acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, lignoserine Saturated fatty acids such as acid, serotic acid, heptacosanoic acid, montanic acid, melicinic acid, lactelic acid, isovaleric acid, and acrylic acid, crotonic acid, isocrotonic acid, undecylenic acid, oleic acid, elaidic acid, celetic acid, nillic acid, buteticidin Examples also include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, propiolic acid, stearolic acid, sardine acid, talylic acid and licanoic acid. More preferably, it is a fatty acid that is liquid at 50 ° C., more preferably 5 to 25 carbon atoms, and most preferably 8 to 21 carbon atoms. These sensitizers can be used alone or in combination of two or more. A preferable range for the amount used is 0.01 to 10% by mass, and a more preferable range is 0.05 to 5% by mass.

  The photosensitive lithographic printing plate material of the present invention has an unexposed portion after exposure and recording of image information with a laser light source having a light emission wavelength in the range of 350 nm to 450 nm when the lithographic printing plate is produced. It is characterized in that it can be removed by an aqueous solution containing a functional resin and a surfactant and having a pH of 3.0 to 9.0 at a temperature of 25 ° C. Can be used.

  For example, in the present invention, it is one of the preferred embodiments that the unexposed portion can be removed by selecting an appropriate condition for the type and content of the polymerizable monomer contained in the photosensitive layer of the photosensitive lithographic printing plate material. is there. As an example of this embodiment, a polymerizable compound having at least a hydroxyl group in the molecule is selected as the polymerizable monomer to be contained in the photosensitive layer, and a homopolymer or copolymer of at least N-vinylpyrrolidone is used as the polymer binder. It is preferable to select the combination from the viewpoint of solving the problem according to the present invention.

Further, in order to be able to remove the unexposed part, as another means, after exposing and recording image information with a laser light source on the photosensitive lithographic printing material of the present invention, the temperature of the plate surface is 80 ° C. to 160 ° C. A method of removing unexposed portions with the aqueous solution through the step of heating to become,
After the step of heating so that the temperature of the plate surface is 80 ° C. to 160 ° C., before the step of removing the unexposed portion with the aqueous solution, a step of removing a part of the oxygen blocking layer and the photosensitive layer by washing with water in advance. It is preferable from the viewpoint of solving the problems according to the present invention.

(Polymerization initiator)
The polymerization initiator according to the present invention is capable of initiating polymerization of a polymerizable ethylenic double bond-containing compound by image exposure. In the present invention, the photosensitive layer has a hexaarylbisimidazole compound as a polymerization initiator. It is characterized by containing.

  Processes for the preparation of hexaarylbiimidazole (HABI, triaryl-imidazole dimer) compounds used in the present invention are described in DE 1,470,154 and their use in photopolymerizable compositions. Use is described in EP 24,629, EP 107,792, US 4,410,621, EP 215,453 and DE 3,211,312.

  Preferred derivatives are, for example, 2,4,5,2 ′, 4 ′, 5′-hexaphenylbiimidazole, 2,2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetraphenylbiimidazole. Imidazole, 2,2'-bis (2-bromophenyl) -4,5,4 ', 5'-tetraphenylbiimidazole, 2,2'-bis (2,4-dichlorophenyl) -4,5,4' , 5'-tetraphenylbiimidazole, 2,2'-bis (2-chlorophenyl) -4,5,4 ', 5'-tetrakis (3-methoxyphenyl) biimidazole, 2,2'-bis (2- Chlorophenyl) -4,5,4 ', 5'-tetrakis (3,4,5-trimethoxyphenyl) -biimidazole, 2,5,2', 5'-tetrakis (2-chlorophenyl) -4,4 ' -Bis (3,4-dimethyl) Xylphenyl) biimidazole, 2,2'-bis (2,6-dichlorophenyl) -4,5,4 ', 5'-tetraphenylbiimidazole, 2,2'-bis (2-nitrophenyl) -4,5 , 4 ', 5'-tetraphenylbiimidazole, 2,2'-di-o-tolyl-4,5,4', 5'-tetraphenylbiimidazole, 2,2'-bis (2-ethoxyphenyl) -4,5,4 ', 5'-tetraphenylbiimidazole and 2,2'-bis (2,6-difluorophenyl) -4,5,4', 5'-tetraphenylbiimidazole.

  In the present invention, as a polymerization initiator, other types of polymerization initiators can be used in combination with hexaarylbiimidazole. For example, titanocene compounds, monoalkyltriaryl borate compounds, iron arene complex compounds, and polyhalogen compounds are preferably used.

  Examples of titanocene compounds include compounds described in JP-A-63-41483 and JP-A-2-291. More preferred specific examples include bis (cyclopentadienyl) -Ti-di-chloride, bis (Cyclopentadienyl) -Ti-bis-phenyl, bis (cyclopentadienyl) -Ti-bis-2,3,4,5,6-pentafluorophenyl, bis (cyclopentadienyl) -Ti-bis -2,3,5,6-tetrafluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,4,6-trifluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,6 -Difluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,4-difluorophenyl, bis (methylcyclopentadienyl) -Ti-bis- , 3,4,5,6-pentafluorophenyl, bis (methylcyclopentadienyl) -Ti-bis-2,3,5,6-tetrafluorophenyl, bis (methylcyclopentadienyl) -Ti-bis -2,6-difluorophenyl (IRUGACURE 727L: manufactured by Ciba Specialty Chemicals), bis (cyclopentadienyl) -bis (2,6-difluoro-3- (py-1-yl) phenyl) titanium (IRUGACURE 784: Ciba Specialty Chemicals), bis (cyclopentadienyl) -bis (2,4,6-trifluoro-3- (pyridin-1-yl) phenyl) titanium bis (cyclopentadienyl) -bis (2, 4,6-trifluoro-3- (2-5-dimethylpy-1-yl) phenyl) titanium and the like It is below.

  Examples of the monoalkyl triaryl borate compound include compounds described in JP-A-62-150242 and JP-A-62-143044, and more preferable specific examples include tetra-n-butylammonium / n-butyl- Trinaphthalen-1-yl-borate, tetra-n-butylammonium / n-butyl-triphenyl-borate, tetra-n-butylammonium / n-butyl-tri- (4-tert-butylphenyl) -borate, tetra -N-butylammonium · n-hexyl-tri- (3-chloro-4-methylphenyl) -borate, tetra-n-butylammonium · n-hexyl-tri- (3-fluorophenyl) -borate, etc. .

  Examples of the iron arene complex compound include compounds described in JP-A-59-219307. More preferred specific examples include η-benzene- (η-cyclopentadienyl) iron hexafluorophosphate, η-cumene. -(Η-cyclopentadienyl) iron hexafluorophosphate, η-fluorene- (η-cyclopentadienyl) iron hexafluorophosphate, η-naphthalene- (η-cyclopentadienyl) iron hexafluorophosphate, η- Examples include xylene- (η-cyclopentadienyl) iron hexafluorophosphate, η-benzene- (η-cyclopentadienyl) iron tetrafluoroborate.

  As the polyhalogen compound, a compound having a trihalogenmethyl group, a dihalogenmethyl group or a dihalomethylene group is preferably used, and in particular, a halogen compound represented by the following general formula (PIH1) and the above group is substituted with an oxadiazole ring. A compound is preferably used.

  Among these, a halogen compound represented by the following general formula (PIH2) is particularly preferably used.

Formula (PIH1) R ¹ —CY ₂ — (C═O) —R ²
In the formula, R ¹ represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an acyl group, an alkylsulfonyl group, an arylsulfonyl group, an iminosulfonyl group, or a cyano group. R ² represents a monovalent substituent. R ¹ and R ² may be bonded to form a ring. Y ₂ represents a halogen atom.

Formula (PIH2) CY ₃ — (C═O) —X—R ³
In the formula, R ³ represents a monovalent substituent. X represents —O— or —NR ⁴ —. R ⁴ represents a hydrogen atom or an alkyl group. R ³ and R ⁴ may be bonded to form a ring. Y ₃ represents a halogen atom. Among these, those having a polyhalogenacetylamide group are particularly preferably used.

  A compound in which a polyhalogen methyl group is substituted on the oxadiazole ring is also preferably used. Furthermore, the oxadiazole compounds described in JP-A Nos. 5-34904, 45875 and 8-240909 are also preferably used.

  A biimidazole compound is a derivative of biimidazole, and examples thereof include compounds described in JP-A No. 2003-295426.

  In addition, any polymerization initiator can be used in combination. For example, J. et al. Carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo, diazo compounds, halogen compounds, and photoreductive dyes as described in Chapter 5 of “Light Sensitive Systems” by J. Kosar Etc. More specific compounds are disclosed in British Patent 1,459,563.

  That is, as the polymerization initiator that can be used in combination, the following can be used.

  Benzoin derivatives such as benzoin methyl ether, benzoin-i-propyl ether, α, α-dimethoxy-α-phenylacetophenone; benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4′-bis (dimethyl) Benzophenone derivatives such as amino) benzophenone; thioxanthone derivatives such as 2-chlorothioxanthone and 2-i-propylthioxanthone; anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone; N-methylacridone, N-butylacridone and the like In addition to α, α-diethoxyacetophenone, benzyl, fluorenone, xanthone and uranyl compounds, JP-B-59-1281, 61-9621 and JP-A-60-60104 Triazine derivatives; organic peroxides described in JP-A-59-1504 and JP-A-61-243807; JP-B-43-23684, JP-A-44-6413, JP-A-44-6413, JP-A-47-1604, and US patents Diazonium compounds described in US Pat. No. 3,567,453; organic azide compounds described in US Pat. Nos. 2,848,328 and 2,852,379 and 2,940,853; O-quinonediazides described in JP-A Nos. 13109, 38-18015 and 45-9610; JP-B-55-39162, JP-A-59-14023 and “Macromolecules”, Vol. 10, 1307 Various onium compounds described on page 1977; azo compounds described in JP-A-59-142205 Compound: JP-A-1-54440, European Patents 109,851, 126,712 and “Journal of Imaging Science (J. Imag. Sci.)”, Vol. 30, 174 (1986) (Oxo) sulfonium organoboron complexes described in Japanese Patent Application Nos. 4-56831 and 4-89535; "Coordination Chemistry Review", 84, 85-277 (1988) ) And transition metal complexes containing a transition metal such as ruthenium described in JP-A-2-182701; 2,4,5-triarylimidazole dimer described in JP-A-3-209477; carbon tetrabromide, JP Organic halogen compounds described in JP-A-59-107344, etc.

  The content of the polymerization initiator according to the present invention (total amount of polymerization initiator) is preferably 0.1% by mass to 20% by mass and preferably 0.5% by mass to 15% with respect to the polymerizable ethylenically unsaturated bond-containing compound. Mass% is particularly preferred.

(Polymerizable monomer)
The polymerizable monomer is a compound (monomer) that can be polymerized with the product of the reaction of the polymerization initiator by image exposure as a trigger. As the polymerizable monomer according to the present invention, a wide range of compounds that can start a polymerization reaction triggered by a reaction with a radical species generated from the polymerization initiator according to the present invention can be used.

  As the polymerizable monomer according to the present invention, an ethylenically unsaturated bond-containing compound that is preferably used is a polymerizable compound, which is generally used for general radical polymerizable monomers and ultraviolet curable resins. Polyfunctional monomers and polyfunctional oligomers having a plurality of addition-polymerizable ethylenic double bonds in the molecule to be used.

  The polymerizable monomer according to the present invention is not limited, but preferred examples thereof include 2-ethylhexyl acrylate, 2-hydroxypropyl acrylate, glycerol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate, tetrahydrofurfuryl. Monofunctional acrylic acid esters such as oxyethyl acrylate, tetrahydrofurfuryloxyhexanolide acrylate, acrylate of ε-caprolactone adduct of 1,3-dioxane alcohol, 1,3-dioxolane acrylate, or methacrylates of these acrylates, Methacrylic acid, itaconic acid, crotonic acid, maleate esters such as ethylene instead of itaconate, crotonate, maleate Recall diacrylate, Triethylene glycol diacrylate, Pentaerythritol diacrylate, Hydroquinone diacrylate, Resorcin diacrylate, Hexanediol diacrylate, Neopentyl glycol diacrylate, Tripropylene glycol diacrylate, Diacrylate of hydroxypivalate neopentyl glycol Diacrylate of neopentyl glycol adipate, diacrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate, 2- (2-hydroxy-1,1-dimethylethyl) -5-hydroxymethyl-5-ethyl-1 , 3-dioxane diacrylate, tricyclodecane dimethylol acrylate, ε-cation of tricyclodecane dimethylol acrylate Lactone adduct, bifunctional acrylic acid ester such as diacrylate of diglycidyl ether of 1,6-hexanediol, or methacrylic acid, itaconic acid, crotonic acid in which these acrylates are replaced with methacrylate, itaconate, crotonate, maleate, Maleic acid esters, such as trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate , Ε-caprolactone adduct of dipentaerythritol hexaacrylate, pyroga Multifunctional acrylic acid ester acid such as methyltriacrylate, propionic acid / dipentaerythritol triacrylate, propionic acid / dipentaerythritol tetraacrylate, hydroxypivalylaldehyde-modified dimethylolpropane triacrylate, or these acrylates with methacrylate, itaconate, Mention may be made of methacrylic acid, itaconic acid, crotonic acid, maleic acid ester, etc. instead of crotonate and maleate.

  Prepolymers can also be used as described above. Examples of the prepolymer include compounds as described below, and a prepolymer obtained by introducing acrylic acid or methacrylic acid into an oligomer having an appropriate molecular weight and imparting photopolymerizability can be preferably used. These prepolymers may be used singly or in combination of two or more, and may be used by mixing with the above-mentioned monomers and / or oligomers.

  Examples of prepolymers include adipic acid, trimellitic acid, maleic acid, phthalic acid, terephthalic acid, hymic acid, malonic acid, succinic acid, glutaric acid, itaconic acid, pyromellitic acid, fumaric acid, glutaric acid, pimelic acid, Polybasic acids such as sebacic acid, dodecanoic acid, tetrahydrophthalic acid, and ethylene glycol, propylene glycol, diethylene glycol, propylene oxide, 1,4-butanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, trimethylol Polyester obtained by introducing (meth) acrylic acid into a polyester obtained by combining polyhydric alcohols such as propane, pentaerythritol, sorbitol, 1,6-hexanediol, 1,2,6-hexanetriol Chlorates such as bisphenol A, epichlorohydrin, (meth) acrylic acid, and epoxy acrylates in which (meth) acrylic acid is introduced into an epoxy resin such as phenol novolac, epichlorohydrin, (meth) acrylic acid, such as ethylene glycol, adipine Acid / tolylene diisocyanate / 2-hydroxyethyl acrylate, polyethylene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate, hydroxyethylphthalyl methacrylate / xylene diisocyanate, 1,2-polybutadiene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate , Trimethylolpropane, propylene glycol, tolylene diisocyanate, 2-hydroxyethyl acrylate In addition, urethane acrylates in which (meth) acrylic acid is introduced into urethane resin, for example, silicone resin acrylates such as polysiloxane acrylate, polysiloxane diisocyanate, 2-hydroxyethyl acrylate, etc., and (meth) acryloyl in oil-modified alkyd resins Examples thereof include prepolymers such as alkyd-modified acrylates having introduced groups and spirane resin acrylates.

  The photosensitive layer according to the present invention includes a phosphazene monomer, triethylene glycol, isocyanuric acid EO (ethylene oxide) modified diacrylate, isocyanuric acid EO modified triacrylate, dimethylol tricyclodecane diacrylate, trimethylolpropane benzoic acid benzoic acid. Addition-polymerizable oligomers and prepolymers having monomers such as esters, alkylene glycol type acrylic acid-modified, urethane-modified acrylates, and structural units formed from the monomers can be contained.

  Furthermore, examples of the ethylenic monomer that can be used in combination with the present invention include phosphate ester compounds containing at least one (meth) acryloyl group. The compound is not particularly limited as long as it is a compound in which at least part of the hydroxyl group of phosphoric acid is esterified and has a (meth) acryloyl group.

  In addition, JP-A-58-212994, 61-6649, 62-46688, 62-48589, 62-173295, 62-187092, 63- 67189, JP-A-1-244891, and the like. Further, “11290 Chemical Products”, Chemical Industry Daily, p. 286-p. 294, “UV / EB Curing Handbook (raw material)”, Kobunshi Publishing Co., p. The compounds described in 11 to 65 can also be suitably used in the present invention. Of these, compounds having two or more acrylic groups or methacryl groups in the molecule are preferred in the present invention, and those having a molecular weight of 10,000 or less, more preferably 5,000 or less are preferred.

  In the photosensitive layer according to the present invention, it is preferable to use an addition-polymerizable ethylenic double bond-containing compound containing a tertiary amino group in the molecule, which is a tertiary amine monomer. Although there is no particular limitation on the structure, a tertiary amine compound having a hydroxyl group modified with glycidyl methacrylate, methacrylic acid chloride, acrylic acid chloride or the like is preferably used. Specifically, polymerizable compounds described in JP-A-1-165613, JP-A-1-203413, and JP-A-1-197213 are preferably used.

  Furthermore, in the present invention, a tertiary amine monomer, a polyhydric alcohol containing a tertiary amino group in the molecule, a diisocyanate compound, and a compound containing an ethylenic double bond capable of addition polymerization with a hydroxyl group in the molecule are used. It is preferred to use a reaction product.

  Examples of the polyhydric alcohol having a tertiary amino group in the molecule include triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-tert. -Butyldiethanolamine, N, N-di (hydroxyethyl) aniline, N, N, N ', N'-tetra-2-hydroxypropylethylenediamine, p-tolyldiethanolamine, N, N, N', N'-tetra- 2-hydroxyethylethylenediamine, N, N-bis (2-hydroxypropyl) aniline, allyldiethanolamine, 3- (dimethylamino) -1,2-propanediol, 3-diethylamino-1,2-propanediol, N, N -Di (n-propyl) amino-2,3-propanediol, N, N-di (iso-propyl) amino-2,3-propanediol, 3- (N-methyl-N-benzylamino) -1, Although 2-propanediol etc. are mentioned, it is not limited to this.

  Examples of the diisocyanate compound include butane-1,4-diisocyanate, hexane-1,6-diisocyanate, 2-methylpentane-1,5-diisocyanate, octane-1,8-diisocyanate, 1,3-diisocyanate methyl-cyclohexanone. 2,2,4-trimethylhexane-1,6-diisocyanate, isophorone diisocyanate, 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene-2,4-diisocyanate, tolylene- Examples include 2,5-diisocyanate, tolylene-2,6-diisocyanate, 1,3-di (isocyanatomethyl) benzene, 1,3-bis (1-isocyanato-1-methylethyl) benzene, and the like. Limited to Not.

  Examples of the compound containing a hydroxyl group and addition-polymerizable ethylenic double bond in the molecule include 2-hydroxyethyl methacrylate (MH-1), 2-hydroxyethyl acrylate (MH-2), 4-hydroxybutyl. Examples include acrylate (MH-4), 2-hydroxypropylene-1,3-dimethacrylate (MH-7), 2-hydroxypropylene-1-methacrylate-3-acrylate (MH-8), and the like.

  Specific examples of polyhydric alcohol containing a tertiary amino group in the molecule, a diisocyanate compound, and a compound containing an ethylenic double bond capable of addition polymerization with a hydroxyl group in the molecule are as follows. As a reaction product. These reactions can be carried out in the same manner as a method for synthesizing urethane acrylate by a reaction of a normal diol compound, diisocyanate compound, and hydroxyl group-containing acrylate compound.

M-1: reaction product of triethanolamine (1 mol), hexane-1,6-diisocyanate (3 mol), 2-hydroxyethyl methacrylate (3 mol) M-2: triethanolamine (1 mol), isophorone Reaction product of diisocyanate (3 mol) and 2-hydroxyethyl acrylate (3 mol) M-3: Nn-butyldiethanolamine (1 mol), 1,3-bis (1-isocyanato-1-methylethyl) Reaction product of benzene (2 mol) and 2-hydroxypropylene-1-methacrylate-3-acrylate (2 mol) M-4: Nn-butyldiethanolamine (1 mol), 1,3-di (isocyanatomethyl) ) Reaction of benzene (2 mol), 2-hydroxypropylene-1-methacrylate-3-acrylate (2 mol) Product M-5: Reaction product of N-methyldiethanolamine (1 mol), tolylene-2,4-diisocyanate (2 mol), 2-hydroxypropylene-1,3-dimethacrylate (2 mol) An acrylate or an alkyl acrylate described in JP-A-1-105238 and JP-A-2-127404 can be used.

  In the present invention, among the polymerizable monomers, it is particularly preferable to use a polymerizable compound having a hydroxyl group in the molecule in order to solve the above-mentioned problem according to the present invention.

  As the polymerizable compound having a hydroxyl group in the molecule that can be used in the present invention, a compound represented by the following general formula (PMOH) is preferable.

[Wherein, R ¹ represents a hydrogen atom or a methyl group, and X ¹ represents —CH ₂ —CR ² R ³ —CH ₂ —, — (CH ₂ —CH (OR ⁴ ) —CH ₂ —O) _m —. CH ₂ —CH (OR ⁵ ) CH ₂ —, — (CH (R ⁶ ) CH ₂ O) _n —CH (R ⁶ ) CH ₂ —, —CO—X ² —CO— or —X ² — is represented. R ² and R ³ each independently represents a hydrogen atom, an alkyl group, or a substituted alkyl group. R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom or an alkyl group. X ² represents an arylene group, an alkylene group, or a cycloalkylene group. m and n represent the integer of 1-20. ]
Preferable alkyl groups of R ^{2 to} R ⁶ in the general formula (PMOH) include, for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group and the like. Of these, an alkyl group having 1 to 10 carbon atoms is preferable. Particularly preferably, an alkyl group having 1 to 5 is mentioned, and R ² and R ³ are particularly preferably an alkyl group having 1 to 4 carbon atoms, and R ^{4 to} R ⁶ are particularly preferably a methyl group.

  Substituents of substituted alkyl include aryl groups (eg, phenyl group, naphthyl group, etc.), alkoxyl groups (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, etc.), alkoxycarbonyl groups ( For example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, etc.), amide group (for example, Methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group), amino group (example) For example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine) Atom, bromine atom, etc.).

  Among these substituents, an aryl group, an amino group, an amide group, an alkoxycarbonyl group, and a hydroxyl group are preferable.

Examples of the alkylene group for X ² include an ethylene group, a trimethylene group, a tetramethylene group, a propylene group, an ethylethylene group, a pentamethylene group, a hexamethylene group, and a 2,2,4-trimethylhexamethylene group.

  Examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group.

  Examples of the arylene group include a phenylene group and a naphthylene group.

  Specific examples of the compound represented by the general formula (PMOH) according to the present invention are given below, but the present invention is not limited thereto.

(Spectral sensitizer)
The photosensitive layer according to the present invention needs to contain a spectral sensitizer having an absorption maximum wavelength of 350 to 450 nm as a spectral sensitizer.

  Examples of the spectral sensitizer include cyanine, merocyanine, porphyrin, spiro compound, ferrocene, fluorene, fulgide, imidazole, perylene, phenazine, phenothiazine, acridine, acridone, azo compound, diphenylmethane, triphenylmethane, triphenylamine, coumarin. Derivatives, quinacridone, indigo, styryl, pyrylium compounds, pyromethene compounds, pyrazolotriazole compounds, benzothiazole compounds, barbituric acid derivatives, thiobarbituric acid derivatives, ketoalcohol borate complexes, and the like.

  Examples of the coumarin derivatives include B-1 to B-22 coumarin derivatives of JP-A-8-129258, D-1 to D-32 coumarin derivatives of JP-A 2003-21901, and JP-A 2002. No. 1-363206, 1 to 21 coumarin derivatives, JP 2002-363207 A to 40 coumarin derivatives, JP 2002-363208 A to 34 coumarin derivatives, JP 2002-363209 A, Examples thereof include 1 to 56 coumarin derivatives and can be preferably used.

  Examples of other dyes that can be preferably used include, for example, JP-A No. 2000-98605, JP-A No. 2000-147663, JP-A No. 2000-206690, JP-A No. 2000-258910, JP-A No. 2000-309724, and JP-A No. 2001. And spectral sensitizers described in JP-A-042525, JP-A-2002-202598, and JP-A-2000-221790.

(Polymer binder)
The polymer binder according to the present invention is capable of supporting the components contained in the photosensitive layer on a support. Examples of the polymer binder include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, Polyester resin, epoxy resin, phenol resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl formal resin, shellac, and other natural resins can be used. Two or more of these may be used in combination.

  A vinyl copolymer obtained by copolymerization of acrylic monomers is preferred. Furthermore, the copolymer composition of the polymer binder is preferably a copolymer of (a) a carboxyl group-containing monomer, (b) a methacrylic acid alkyl ester, or an acrylic acid alkyl ester.

  Specific examples of the carboxyl group-containing monomer include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride and the like. In addition, carboxylic acids such as phthalic acid and 2-hydroxymethacrylate half ester are also preferable.

  Specific examples of alkyl methacrylates and alkyl esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate. , Decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, acrylic In addition to unsubstituted alkyl esters such as decyl acid, undecyl acrylate and dodecyl acrylate, cyclic alkyl esters such as cyclohexyl methacrylate and cyclohexyl acrylate Substituted alkyl esters such as benzyl methacrylate, 2-chloroethyl methacrylate, N, N-dimethylaminoethyl methacrylate, glycidyl methacrylate, benzyl acrylate, 2-chloroethyl acrylate, N, N-dimethylaminoethyl acrylate, and glycidyl acrylate Also mentioned.

  Further, in the polymer binder, monomers described in the following (1) to (14) can be used as copolymerization monomers.

  1) Monomers having an aromatic hydroxyl group, such as o- (or p-, m-) hydroxystyrene, o- (or p-, m-) hydroxyphenyl acrylate and the like.

  2) Monomers having an aliphatic hydroxyl group, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, N-methylol methacrylamide, 4-hydroxybutyl methacrylate, 5-hydroxypentyl acrylate, 5-hydroxypentyl methacrylate , 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide, hydroxyethyl vinyl ether and the like.

  3) A monomer having an aminosulfonyl group, such as m- (or p-) aminosulfonylphenyl methacrylate, m- (or p-) aminosulfonylphenyl acrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p -Aminosulfonylphenyl) acrylamide and the like.

  4) Monomers having a sulfonamide group, such as N- (p-toluenesulfonyl) acrylamide, N- (p-toluenesulfonyl) methacrylamide and the like.

  5) Acrylamide or methacrylamides such as acrylamide, methacrylamide, N-ethylacrylamide, N-hexylacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N- (4-nitrophenyl) acrylamide, N-ethyl-N- Phenylacrylamide, N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide and the like.

  6) Monomers containing fluorinated alkyl groups such as trifluoroethyl acrylate, trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, hexafluoropropyl methacrylate, octafluoropentyl acrylate, octafluoropentyl methacrylate, heptadecafluorodecyl methacrylate, N- Butyl-N- (2-acryloxyethyl) heptadecafluorooctylsulfonamide and the like.

  7) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether and the like.

  8) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate and the like.

  9) Styrenes such as styrene, methyl styrene, chloromethyl styrene and the like.

  10) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.

  11) Olefins such as ethylene, propylene, i-butylene, butadiene, isoprene and the like.

  12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine and the like.

  13) Monomers having a cyano group, such as acrylonitrile, methacrylonitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile, 2-cyanoethyl acrylate, o- (or m-, p-) cyanostyrene.

  14) A monomer having an amino group, such as N, N-diethylaminoethyl methacrylate, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, polybutadiene urethane acrylate, N, N-dimethylaminopropyl acrylamide, N, N-dimethylacrylamide, acryloylmorpholine, Ni-propylacrylamide, N, N-diethylacrylamide and the like.

  Further, other monomers that can be copolymerized with these monomers may be copolymerized.

  Furthermore, the polymer binder is preferably a vinyl polymer having a carboxyl group and a polymerizable double bond in the side chain. For example, an unsaturated bond-containing vinyl copolymer obtained by addition-reacting a compound having a (meth) acryloyl group and an epoxy group in the molecule to a carboxyl group present in the molecule of the vinyl copolymer. Is also preferred as a polymer binder.

  Specific examples of the compound containing both an unsaturated bond and an epoxy group in the molecule include glycidyl acrylate, glycidyl methacrylate, and an epoxy group-containing unsaturated compound described in JP-A No. 11-271969. In addition, an unsaturated bond-containing vinyl copolymer obtained by adding a compound having a (meth) acryloyl group and an isocyanate group in the molecule to a hydroxyl group present in the molecule of the vinyl polymer is also high. Preferred as a molecular binder. Compounds having both an unsaturated bond and an isocyanate group in the molecule include vinyl isocyanate, (meth) acrylic isocyanate, 2- (meth) acryloyloxyethyl isocyanate, m- or p-isopropenyl-α, α'-dimethylbenzyl. Isocyanates are preferred, and (meth) acrylic isocyanate, 2- (meth) acryloyloxyethyl isocyanate and the like can be mentioned.

  The vinyl polymer having a carboxyl group and a polymerizable double bond in the side chain is preferably 50 to 100% by mass, and more preferably 100% by mass in the total polymer binder.

  In the photosensitive lithographic printing plate material of the present invention, among the above-mentioned polymer binders, in particular, it is possible to contain a homopolymer or copolymer of N-vinylpyrrolidone in the photosensitive layer. Preferred for.

  When a copolymer of N-vinylpyrrolidone is used, the monomer to be copolymerized is not particularly limited, but vinyl acetate can be preferably used.

  The content of the polymer binder in the photosensitive layer is preferably in the range of 10 to 90% by mass, more preferably in the range of 15 to 70% by mass, and the use in the range of 20 to 50% by mass from the viewpoint of sensitivity. Particularly preferred.

(Various additives)
In the photosensitive layer according to the present invention, in addition to the above-mentioned various components, in order to prevent unnecessary polymerization of an ethylenic double bond monomer that can be polymerized during production or storage of a photosensitive lithographic printing plate material, It is desirable to add a polymerization inhibitor.

  Suitable polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol) 2,2'-methylenebis (4-methyl-6-t-butylphenol), N-nitrosophenylhydroxylamine cerium salt, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5) -Methylbenzyl) -4-methylphenyl acrylate and the like.

  The addition amount of the polymerization inhibitor is preferably about 0.01% to about 5% with respect to the mass of the total solid content of the photosensitive layer. If necessary, higher fatty acid derivatives such as behenic acid and behenic acid amide may be added to prevent polymerization inhibition due to oxygen, or it may be unevenly distributed on the surface of the photosensitive layer during the drying process after coating. Good. The amount of the higher fatty acid derivative added is preferably about 0.5% to about 10% of the total composition.

  Moreover, a coloring agent can also be used and a conventionally well-known thing can be used conveniently as a coloring agent including a commercially available thing. Examples include those described in the revised new edition “Pigment Handbook”, edited by Japan Pigment Technology Association (Seikodo Shinkosha), Color Index Handbook, and the like.

  Examples of the pigment include black pigment, yellow pigment, red pigment, brown pigment, purple pigment, blue pigment, green pigment, fluorescent pigment, and metal powder pigment. Specifically, inorganic pigments (titanium dioxide, carbon black, graphite, zinc oxide, Prussian blue, cadmium sulfide, iron oxide, and lead, zinc, barium and calcium chromates) and organic pigments (azo-based, thioindigo) , Anthraquinone, anthanthrone, and triphendioxazine pigments, vat dye pigments, phthalocyanine pigments and derivatives thereof, quinacridone pigments, and the like.

  Among these, it is preferable to select and use a pigment having substantially no absorption in the absorption wavelength region of the spectral sensitizing dye corresponding to the exposure laser to be used. In this case, an integrating sphere at the laser wavelength to be used is used. It is preferable that the reflection absorption of the used pigment is 0.05 or less. Moreover, as an addition amount of a pigment, 0.1-10 mass% is preferable with respect to solid content of the said composition, More preferably, it is 0.2-5 mass%.

  From the viewpoints of pigment absorption in the above-mentioned photosensitive wavelength region and visible image properties after development, violet pigments and blue pigments are preferably used. Such as, for example, cobalt blue, cerulean blue, alkali blue lake, phonatone blue 6G, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue first sky blue, indanthrene blue, indico, dioxane violet, iso Violanthrone Violet, Indanthrone Blue, Indanthrone BC and the like can be mentioned. Among these, phthalocyanine blue and dioxane violet are more preferable.

  In addition, the photosensitive layer can contain a surfactant as a coating property improving agent as long as the performance of the present invention is not impaired. Of these, fluorine-based surfactants are preferred.

  In order to improve the physical properties of the cured film, additives such as an inorganic filler, a plasticizer such as dioctyl phthalate, dimethyl phthalate, and tricresyl phosphate may be added. These addition amounts are preferably 10% or less of the total solid content.

  Examples of the solvent used in preparing the photosensitive layer coating solution for the photosensitive layer according to the present invention include, for example, alcohol: polyhydric alcohol derivatives, sec-butanol, isobutanol, n-hexanol, benzyl alcohol, Diethylene glycol, triethylene glycol, tetraethylene glycol, 1,5-pentanediol, ethers: propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, ketones, aldehydes: diacetone alcohol, cyclohexanone Preferred examples include methylcyclohexanone and esters: ethyl lactate, butyl lactate, diethyl oxalate, methyl benzoate and the like.

  Although the photosensitive layer coating solution has been described above, the photosensitive layer according to the present invention is formed by coating on a support using the photosensitive layer.

Photosensitive layer according to the present invention as the amount per on the ^{support, 0.1g / m 2 ~10g / m} 2 are preferred, especially 0.5g / m ² ~5g / m ² is preferred.

(Oxygen barrier layer)
On the upper side of the photosensitive layer according to the present invention, an oxygen blocking layer having an oxygen blocking function and, if necessary, other protective functions is provided.

  This oxygen barrier layer preferably has high solubility in a developer (described below, generally an aqueous alkali solution) described below. Therefore, the present invention is characterized by containing polyvinyl alcohol. Polyvinyl alcohol has an effect of suppressing the permeation of oxygen. In addition, it is preferable to use together polyvinyl pyrrolidone which has the effect of ensuring adhesiveness with the adjacent photosensitive layer.

  In addition to the above two polymers, polysaccharides, polyethylene glycol, gelatin, glue, casein, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, hydroxyethyl starch, gum arabic, sucrose octaacetate, ammonium alginate, sodium alginate as required Water-soluble polymers such as polyvinylamine, polyethylene oxide, polystyrene sulfonic acid, polyacrylic acid, and water-soluble polyamide can also be used in combination.

  When an oxygen blocking layer is provided on the photosensitive lithographic printing plate of the present invention, the peel force between the photosensitive layer and the oxygen blocking layer is preferably 35 mN / mm or more, more preferably 50 mN / mm or more, and even more preferably 75 mN / mm. That's it. Preferred examples of the composition of the oxygen barrier layer include those described in JP-A-10-10742.

  The peeling force in the present invention is such that an adhesive tape having a predetermined width having a sufficiently large adhesive force is applied on the oxygen barrier layer, and then peeled off with the oxygen barrier layer at an angle of 90 degrees with respect to the plane of the photosensitive lithographic printing plate material. It can be determined by measuring the force of time.

  The oxygen barrier layer can further contain a surfactant, a matting agent and the like as required. The oxygen barrier layer composition is dissolved in a suitable solvent, applied onto the photosensitive layer and dried to form an oxygen barrier layer. The main component of the coating solvent is particularly preferably water or alcohols such as methanol, ethanol, i-propanol.

  When the oxygen barrier layer is provided, the thickness is preferably from 0.1 to 5.0 μm, particularly preferably from 0.5 to 3.0 μm.

(Support)
The support according to the present invention is a plate or film capable of carrying a photosensitive layer, and preferably has a hydrophilic surface on the side where the photosensitive layer is provided.

  Examples of the support according to the present invention include a metal plate such as aluminum, stainless steel, chromium and nickel, or a laminate obtained by laminating or vapor-depositing the above metal thin film on a plastic film such as a polyester film, a polyethylene film and a polypropylene film. .

  Moreover, although what hydrophilized the surface, such as a polyester film, a vinyl chloride film, a nylon film, etc. can be used, an aluminum support body is used preferably.

  In the case of an aluminum support, pure aluminum or an aluminum alloy is used.

  Various aluminum alloys can be used as the support, and for example, alloys of metals such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, titanium, sodium, iron, and aluminum are used. . Further, the aluminum support having a roughened surface is used for water retention.

  In the case of using an aluminum support, it is preferable to perform 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 support. In this case, the substrate 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 electrochemical surface roughening method is not particularly limited, but a method of electrochemical surface roughening in an acidic electrolyte is preferable.

  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, 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, an anodic oxidation treatment can be 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 support.

  The anodized support may be sealed 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.

  Furthermore, after performing these treatments, water-soluble resins such as polyvinylphosphonic acid, polymers and copolymers having sulfonic acid groups in the side chain, polyacrylic acid, water-soluble metal salts (for example, zinc borate) or Also suitable are those coated with a yellow dye, amine salt or the like. 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.

(Application)
The above photosensitive layer coating solution can be coated on a support by a conventionally known method and dried to prepare a photosensitive lithographic printing plate material.

  Examples of coating methods for the coating liquid include air doctor coater method, blade coater method, wire bar method, knife coater method, dip coater method, reverse roll coater method, gravure coater method, cast coating method, curtain coater method and extrusion coater method. I can list them.

  The drying temperature of the photosensitive layer is preferably in the range of 60 to 160 ° C., more preferably 80 to 140 ° C., and particularly preferably 90 to 120 ° C.

(Image exposure)
As a light source for recording an image on the photosensitive lithographic printing plate material of the present invention, laser light having an emission wavelength of 350 to 450 nm is preferably used.

As a light source for exposing the photosensitive lithographic printing plate of the present invention, for example, a He—Cd laser (441 nm), a combination of Cr: LiSAF and SHG crystal (430 nm) as a solid-state laser, KNbO ₃ as a semiconductor laser system, a ring A resonator (430 nm), AlGaInN (350 nm to 450 nm), an AlGaInN semiconductor laser (commercially available InGaN-based semiconductor laser 400 to 410 nm) and the like can be mentioned.

  In the case of laser exposure, light can be reduced in the form of a beam and scanning exposure can be performed in accordance with image data, which is suitable for direct writing without using a mask material.

  When a laser is used as a light source, it is easy to reduce the exposure area to a very small size, and high-resolution image formation is possible.

  Laser scanning methods include cylindrical outer surface scanning, cylindrical inner surface scanning, and planar scanning. In the cylindrical outer surface scanning, laser exposure is performed while rotating a drum around which the recording material is wound, and the rotation of the drum is set as main scanning, and the movement of laser light is set as sub scanning. In cylindrical inner surface scanning, a recording material is fixed to the inner surface of a drum, a laser beam is irradiated from the inside, and a main scanning is performed in the circumferential direction by rotating a part or all of the optical system. Sub scanning is performed in the axial direction by linearly moving all of them in parallel with the drum axis. In planar scanning, main scanning of laser light is performed by combining a polygon mirror or galvanometer mirror and an fθ lens, and sub scanning is performed by moving a recording medium. Cylindrical outer surface scanning and cylindrical inner surface scanning are easier to increase the accuracy of the optical system and are suitable for high-density recording.

In the present invention, image exposure is preferably performed with a plate surface energy (energy on the plate material) of 10 mJ / cm ² or more, and the upper limit is 500 mJ / cm ² . More preferably, it is 10-300 mJ / cm < ² >. For this energy measurement, for example, a laser power meter PDGDO-3W manufactured by OphirOptics can be used.

(Automatic processor)
It is generally photosensitive to remove the unexposed portion of the photosensitive lithographic printing plate material of the present invention with an aqueous solution containing a water-soluble resin and a surfactant and having a pH of 3.0 to 9.0 at 25 ° C. It is advantageous to use an automatic processor used for the development of lithographic printing plate materials. The automatic processor is preferably provided with a heat treatment apparatus for performing a heat treatment after inserting the exposed photosensitive lithographic printing plate material and before removing the unexposed portion. As the heat treatment apparatus, heat treatment is performed by radiant heat such as a ceramic heater, or heat treatment is performed by hot air heated by a ceramic heater or the like, and the temperature of the plate surface is set to an arbitrary temperature within a range of 80 ° C to 160 ° C. Those that can be adjusted are preferable. Further, it can have a water washing portion for removing part of the oxygen blocking layer and the photosensitive layer after the heat treatment. Examples of the washing unit include those equipped with a shower nozzle that supplies washing water to the plate surface, and those that immerse the plate in a washing tank filled with washing water. Those provided with a mechanism for rubbing the plate surface with a roller-like brush are also preferred.

  In the step of removing the unexposed area with an aqueous solution containing a water-soluble resin and a surfactant and having a pH of 3.0 to 9.0 at 25 ° C., a development process for a normal general photosensitive lithographic printing plate material It is possible to use a developing bath of an automatic developing machine used for the above. The developing bath preferably has a mechanism capable of adjusting the aqueous solution to a constant temperature. It is preferable that the temperature adjustment can be arbitrarily set within a range of 20 to 35 ° C. Further, a mechanism for automatically replenishing the required amount of the aqueous solution is provided. Preferably, the aqueous solution in excess of a certain amount is provided with a mechanism for discharging, preferably a mechanism for detecting plate passing. Preferably, a mechanism for estimating the processing area of the plate based on the detection of the plate is provided, preferably replenishment of the replenisher to be replenished based on the detection of the plate and / or the estimation of the processing area A mechanism for controlling the amount and / or replenishment timing is provided, preferably a mechanism for controlling the temperature of the aqueous solution is provided, and preferably a mechanism for detecting the pH and / or conductivity of the aqueous solution is provided. Preferably, a mechanism for controlling the replenishment amount and / or replenishment timing of the replenisher and / or water to be replenished based on the pH and / or conductivity of the aqueous solution is provided.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this. In the examples, “parts” represents “parts by mass” unless otherwise specified.

[Production of support]
Using a JIS A 1050 aluminum plate having a thickness of 0.30 mm and a width of 1030 mm, the treatment was continuously performed as follows.

(A) The aluminum plate was etched by spraying at a caustic soda concentration of 2.6 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C. to dissolve the aluminum plate by 0.3 g / m ² . Thereafter, washing with water was performed by spraying.

  (B) A desmut treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid having a temperature of 30 ° C. (including 0.5% by mass of aluminum ions), and then washed with water by spraying.

(C) An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time contains 1.1% by mass of hydrochloric acid, 0.5% by mass of aluminum ions, and 0.5% by mass of acetic acid. The temperature was 21 ° C. The AC power source was subjected to electrochemical surface roughening treatment using a sine wave alternating current having a time TP of 2 msec until the current value reached a peak from zero, using a carbon electrode as a counter electrode. The current density was an effective value of 50 A / dm ² and the energization amount was 900 C / dm ² . Then, water washing by spraying was performed.

  (D) A desmut treatment was performed for 10 seconds with a phosphoric acid concentration 20 mass% aqueous solution (containing 0.5 mass% of aluminum ions) at a temperature of 60 ° C., followed by water washing by spraying.

  (E) An anodizing apparatus of an existing two-stage feed electrolytic treatment method (first and second electrolysis unit length 6 m, first feed unit length 3 m, second feed unit length 3 m, first and second feed electrode lengths 2.4 m each ) Was used to perform anodization at a sulfuric acid concentration of 170 g / liter (containing 0.5 mass% of aluminum ions) at a temperature of 38 ° C. Thereafter, washing with water was performed.

  At this time, in the anodizing device, the current from the power source flows to the first power supply electrode provided in the first power supply unit, flows to the plate-like aluminum via the electrolytic solution, An oxide film is formed on the surface, passes through the electrolytic electrode provided in the first power feeding portion, and returns to the power source.

On the other hand, the current from the power source flows to the second power feeding electrode provided in the second power feeding portion, similarly flows to the plate-like aluminum via the electrolytic solution, and an oxide film is formed on the surface of the plate-like aluminum by the second electrolysis portion. Although the amount of electricity fed from the power source to the first feeding unit and the amount of electricity fed from the power source to the second feeding unit are the same, the feeding current density on the oxide film surface in the second feeding unit is about It was 25 A / dm ² . In the 2nd electric power feeding part, it came to feed from the oxide film surface of 1.35 g / m < ² >. The final oxide film amount was 2.7 g / m ² . Furthermore, after spray water washing, it was immersed in 0.4 mass% polyvinylphosphonic acid solution for 30 seconds, and was hydrophilized. The temperature was 85 ° C. Thereafter, it was washed with spray water and dried with an infrared heater.
At this time, the center line average roughness (Ra) of the surface was 0.65 μm.

(Preparation of photosensitive lithographic printing plate)
On the above support, a photopolymerizable photosensitive layer coating solution having the following composition was applied with a wire bar so that it would be 1.5 g / m ² when dried, and dried at 95 ° C. for 1.5 minutes. Got.

Further, on the photopolymerized photosensitive layer coating sample, an oxygen barrier layer coating solution having the following composition was coated with a wire bar so that the drying rate became 2.0 g / m ² and dried at 65 ° C. for 3 minutes. A photosensitive lithographic printing plate sample having an oxygen blocking layer was prepared.

(Photopolymerizable photosensitive layer coating solution 1)
Polymerizable monomer 1 5.0 parts Polymerizable monomer 2 25.0 parts Polymerizable monomer 3 25.0 parts N-carboxymethylacridone 4.0 parts Polymerization initiator listed in Table 1 3.0 parts Mercapto listed in Table 1 Compound 0.3 part N-vinylpyrrolidone / vinyl acetate copolymer VA64 (manufactured by BASF) 20.0 parts poly (N-vinylpyrrolidone) rubitec K30 (manufactured by BASF) 20.0 parts Acetylene surfactant (Surfi) Nord 465; manufactured by Air Products) 0.5 part phthalocyanine pigment dispersion MHI # 454 (manufactured by Gokoku Dye) 3.0 parts water 450 parts ethanol 450 parts

(Oxygen barrier coating liquid)
Polyvinyl alcohol (GL-05: manufactured by Nippon Synthetic Chemical Co., Ltd.) 90 parts Poly (N-vinylpyrrolidone) Rubitec K30 (manufactured by BASF) 5 parts Polyethyleneimine (Lupazole WF: manufactured by BASF) 5 parts Surfactant (Surfinol 465) : Nissin Chemical Industry Co., Ltd.) 0.5 parts Water 900 parts The plate setter News (manufactured by ECRM Co., Ltd.) equipped with a light source of 405 nm in the environment of yellow safety light is prepared from the photosensitive lithographic printing plate material prepared by the above method. ), And the exposure amount is changed at a resolution of 1200 dpi (dpi represents the number of dots per 2.54 cm) and a line number of 100 lpi (lpi represents the number of lines per 2.54 cm). Were exposed.

  After the exposure, the photosensitive lithographic printing plate material was subsequently heat-treated at 105 ° C. for 30 seconds under an environment of red safety light, and then the plate surface was washed with a tap water shower for 15 seconds to remove the oxygen barrier layer. At this time, a part of the unexposed portion of the photosensitive layer was also removed. Thereafter, the surface was rubbed with a sponge while immersed in an aqueous solution (1) having the following composition for 20 seconds to completely remove the unexposed portion and then dried to obtain a lithographic printing plate.

(Aqueous solution (1))
White dextrin 5.0% by mass
Hydroxypropyl etherified starch 10.0% by mass
Gum arabic 1.0% by mass
1st Ammon Phosphate 0.1% by mass
Sodium dilauryl succinate 0.15% by mass
Polyoxyethylene naphthyl ether 0.5% by mass
Polyoxyethylene polyoxypropylene block copolymer (ethylene oxide ratio 50 mol%, molecular weight 5000) 0.3 mass%
Ethylene glycol 1.0% by mass
1,2 benzoisothiazolin-3-one 0.005 mass%
Phosphoric acid (addition of pH = 3.0 at 25 ° C)
The produced lithographic printing plate was coated with a printing press (DAIYA1F-1 manufactured by Mitsubishi Heavy Industries, Ltd.), printing ink (Toyo King High Echo M Red manufactured by Toyo Ink Co., Ltd.) and dampening water (Tokyo Ink Co., Ltd.). ) H liquid SG-51 concentration 1.5%).

(sensitivity)
On the printed matter after 50 sheets were continuously printed, the exposure amount at which normal image area ink deposition was obtained was evaluated as sensitivity. The smaller the amount of energy, the higher the sensitivity.

(Dirt)
The presence or absence of dirt on the non-image area on the printed material was evaluated.

  The evaluation results are shown in Table 1.

  In Example 4, the polymerizable monomer 3 of the photopolymerizable photosensitive layer coating solution 1 was changed to PMOH-26 as Example 6, and in the comparative example, the polymerization property of the photopolymerizable photosensitive layer coating solution 1 was used. The same procedure as in Example 1 and Comparative Example 1 was performed except that the monomer 3 was similarly changed to PMOH-26, and the other was used as Comparative Example 4. The results are shown in Table 2.

  In Example 6 and Comparative Example 4, the plate surface for removing the oxygen barrier layer was not washed with shower water, and the immersion time in the aqueous solution (1) was changed from 20 seconds to 120 seconds. Example 7 and Comparative Example 5 were carried out in the same manner as Example 6 and Comparative Example 4, respectively. The results are shown in Table 3.

  In Example 6 and Comparative Example 4, the heat treatment at 105 ° C. after the exposure was not performed, and the others were performed in the same manner as in Example 6 and Comparative Example 4 to be Example 8 and Comparative Example 6, respectively. The results are shown in Table 4.

  As is apparent from the results shown in Tables 1 to 4, the examples according to the present invention have higher sensitivity than the comparative examples, and the non-image area is not smeared even by development processing at a low pH. Is shown. Thus, according to the present invention, there is provided a photosensitive lithographic printing plate material which is highly sensitive and does not cause stains in a non-image area even when developed at a low pH, and production of a lithographic printing plate using the same. It can be seen that a method can be provided.

Claims (10)

It has a photosensitive layer containing a spectral sensitizer, a polymerization initiator, a co-initiator, a polymerizable monomer, and a polymer binder on the support, and further has an oxygen barrier layer containing polyvinyl alcohol on it. A photosensitive lithographic printing plate material, wherein the photosensitive layer contains a hexaarylbisimidazole compound as a polymerization initiator, a compound represented by the following general formula (1) as a co-initiator, and a lithographic plate When the printing plate is prepared, the unexposed portion after exposing and recording image information with a laser light source having an emission wavelength in the range of 350 nm to 450 nm contains a water-soluble resin and a surfactant and has a temperature of 25 ° C. A photosensitive lithographic printing plate material, which can be removed with an aqueous solution having a pH of 3.0 to 9.0.

[X represents an oxygen atom, —NR ₁ — or selenium, R ₁ represents an alkyl group which may have a substituent, or an aryl group which may have a substituent, and Y represents N═C—X. It represents an atomic group that forms a 5-membered heterocycle with the moiety, and Y may further have a substituent. ] The photosensitive lithographic printing plate material according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[R ₁ represents an alkyl group that may have a substituent, or an aryl group that may have a substituent, and R ₂ represents a hydrogen atom, an alkyl group that may have a substituent, or a substituent. Represents an aryl group which may have ] The photosensitive lithographic printing plate material according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (3).

[R ₂ represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. ] The photosensitive lithographic printing plate material according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (4).

[R ₁ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. ] The photosensitive lithographic printing plate material according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (5).

[R ₂ and R ₃ each independently represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. ] The photosensitive lithographic printing plate material according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (6).

[R ₁ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. R _{4 to} R ₇ represent a hydrogen atom, a halogen atom, an alkoxyl group, a dialkylamino group, an alkyl group that may have a substituent, or an aryl group that may have a substituent. ] The photosensitive lithographic printing plate material according to claim 1, wherein the photosensitive layer contains a polymerizable compound having a hydroxyl group in the molecule as the polymerizable monomer. The photosensitive lithographic printing plate material according to any one of claims 1 to 7, wherein the photosensitive layer contains a homopolymer or copolymer of N-vinylpyrrolidone as the polymer binder. . After exposing and recording image information with a laser light source on the photosensitive lithographic printing material according to any one of claims 1 to 8, through a step of heating so that the temperature of the plate surface is 80 ° C to 160 ° C, A method for preparing a lithographic printing plate, comprising removing an unexposed portion with an aqueous solution containing a water-soluble resin and a surfactant and having a pH of 3.0 to 9.0 at 25 ° C. After the step of heating so that the temperature of the printing plate is 80 ° C. to 160 ° C., an unexposed portion is formed by an aqueous solution containing a water-soluble resin and a surfactant and having a pH of 3.0 to 9.0 at 25 ° C. 10. The method for producing a lithographic printing plate according to claim 9, further comprising a step of removing a part of the oxygen blocking layer and the photosensitive layer by washing with water before the step of removing.