JP2006201660A - Photosensitive lithographic printing plate material, method for packing the same and plate making method for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithographic printing plate making material which allows imagewise exposure with laser light, has good dot reproducibility and good developability of a non-image area (unexposed area) even after long-term storage, and does not cause scumming in printing, a plate making method for a lithographic printing plate and a method for packing the lithographic printing plate making material. <P>SOLUTION: The photosensitive lithographic printing plate material has: on a support a photosensitive layer comprising a photosensitive composition containing at least a photopolymerization initiator; a polymeric binder; a monomer having an addition polymerizable ethylenically unsaturated bond; and a sensitizing dye. The photosensitive lithographic printing plate material contains an ester compound of a 12-27C fatty acid having a melting point of 50-120°C and an alcohol having 2-5 OH groups in the photosensitive layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photosensitive lithographic printing plate material, a method for making a lithographic printing plate, and a packaging method for a photosensitive lithographic printing plate material.

  In recent years, semiconductor lasers and YAG lasers are increasingly used as light sources for image recording in terms of stability, small size, and ease of maintenance.

  These lasers are becoming shorter in wavelength, and a laser (532 nm) in which SHG is combined with a YAG laser (1064 nm), or a semiconductor laser near 400 nm has been put into practical use.

  A method is known in which imagewise exposure is performed using the laser and radical polymerization is performed to cure an exposed portion, and the physicochemical properties of the unexposed portion are changed, followed by development to form an image. In order to form an image in this way, it is necessary to select a photosensitive material suitable for the wavelength of the laser light source, and many radical generators that serve as initiators for radical polymerization in these photosensitive materials have been studied.

  However, many of them have absorption only in the ultraviolet region alone, and usually a sensitizing dye is used in combination with the wavelength of the light source used. For example, when a 405 nm semiconductor laser or a 532 nm W-YAG laser is used as a light source, a combination of a sensitizing dye and a radical generator (hereinafter referred to as a combination of a sensitizing dye and a radical generator) in order to achieve higher sensitivity than the conventional PS plate. Is sometimes referred to as an initiator system).

  Illustratively, U.S. Pat. No. 2,850,445 describes certain photoreducible dyes as effective sensitizing dyes. Japanese Patent Publication No. 44-20189 discloses a complex initiation system of a dye and an amine, Japanese Patent Publication No. 45-37377 discloses a system of a biimidazole, a radical generator and a dye, Japanese Patent Publication No. 47-2528, Japanese Laid-Open Patent Publication No. 54-155292 discloses a biimidazole and dialkylaminobenzylidene ketone system, Japanese Unexamined Patent Publication No. 58-15503 discloses a keto-substituted coumarin compound and an active halide, Japanese Unexamined Patent Publication No. 54-15102. Describes a system of substituted triazines and merocyanine dyes, and Patent Document 1 describes a system of fluorescent brighteners and halides. However, both of these have poor storage stability and high reactivity, so that there is a problem that halftone dot reproducibility deteriorates due to the shadow portion being crushed or the like (see, for example, Patent Document 2).

On the other hand, especially in the printing industry in recent years, environmental preservation has been screamed, and inks that do not use petroleum-based volatile organic compounds (VOC) have been developed as printing inks. In printed matter using such environmentally friendly printing ink, the shading of the shadow portion appears more prominently.
JP 2003-295426 A JP2003-301209A

  The present invention can perform imagewise exposure using a laser, has good halftone dot reproducibility, and has good developability for non-image areas (unexposed areas) even after long-term storage. The present invention provides a lithographic printing plate making material free of stains, a lithographic printing plate making method, and a lithographic printing plate making material packaging method.

  As a result of intensive studies, the present inventors have found that the object of the present invention can be achieved by adopting the following configuration.

(Claim 1)
Photosensitive having a photosensitive layer comprising a photosensitive composition containing at least a photopolymerization initiator, a polymer binder, a monomer having an addition polymerizable ethylenically unsaturated bond, and a sensitizing dye on a support. In the lithographic printing plate material, the photosensitive layer contains an ester compound of a fatty acid having a melting point of 50 to 120 ° C. and having 12 to 27 carbon atoms and an alcohol having 2 to 5 OH groups. Photosensitive lithographic printing plate material.

(Claim 2)
The photosensitive lithographic printing plate material according to claim 1, comprising 0.1 to 10% by mass of the ester compound.

(Claim 3)
The photosensitive lithographic printing plate material according to claim 1 or 2 is image-exposed with a laser beam of 350 to 600 nm, heated to 90 to 130 ° C, and then contains an inorganic alkaline agent and a surfactant, and has a pH of 10. 5. A method for making a lithographic printing plate, comprising developing with a developer having 5 to 12.7 and an electrical conductivity of 3 to 30 mS / cm.

(Claim 4)
3. A packing method for stacking photosensitive lithographic printing plate materials according to claim 1 or 2, wherein the stacking is performed so that the outermost surface of the photosensitive layer surface and the support surface opposite to the photosensitive layer surface are in contact with each other.

  That is, by incorporating an ester compound of a fatty acid having 12 to 27 carbon atoms having a melting point of 50 ° C. to 100 ° C. and an alcohol having 2 to 5 OH groups in the photosensitive layer, non-sensitivity due to a dark reaction in a high temperature and high humidity environment. The smudge of the image area is improved, and thereby the halftone dot reproducibility is kept good. In particular, remarkable effects can be seen with respect to halftone dot reproducibility in printing using printing inks suitable for the environment and stains in non-image areas.

  Furthermore, pressure bonding between the back surface of the support and the outermost surface of the printing plate material in a high-temperature and high-humidity environment can be suppressed, and good halftone dot reproducibility and storage stability can be obtained.

  According to the present invention, it is possible to perform imagewise exposure using a laser, good dot reproducibility, and good developability for non-image areas (unexposed areas) even after long-term storage. The plate-making plate-making material without stains, the plate-making method of the lithographic printing plate, and the packaging method of the lithographic printing plate-making material can be provided.

  Hereinafter, the compound used in the present invention, the image forming method and the like will be described.

[Ester compound of a fatty acid having 12 to 27 carbon atoms having a melting point of 50 to 100 ° C. and an alcohol having 2 to 5 OH groups]
In the present invention, the reason why an ester compound of a fatty acid having 12 to 27 carbon atoms having a melting point of 50 to 100 ° C. and an alcohol having 2 to 5 OH groups is effective is considered as follows.

  In order to effectively contribute to the polymerization of the ethylenically unsaturated bond portion of the monomer by the radical generated by the cleavage of the photopolymerization initiator in image exposure, the photosensitive layer composition needs to have fluidity, An ester compound of a fatty acid having a melting point of 50 to 100 ° C. and an alcohol having 2 to 5 OH groups is excellent as a compound that imparts fluidity when heated.

  When the melting point is lower than 50 ° C., the photosensitive layer flows and the image forming property deteriorates during long-term storage or transportation of the printing plate material. When the melting point is higher than 100 ° C., the heating temperature after exposure is higher. Therefore, the developability of the non-image area is deteriorated.

  An ester compound with an alcohol having an OH group of 1 is insoluble or hardly soluble in an organic solvent used in the coating liquid preparation, resulting in a coating failure, and a compound having an OH group of more than 5 penetrates too much water. For this reason, the reproducibility of the highlight portion is deteriorated.

  In the present invention, monoester or diester compounds are particularly preferred.

  The addition amount is preferably 0.1 to 10% by mass. If it is less than 0.1% by mass, it can be used as a lithographic printing plate material, but developability slightly deteriorates due to storage in a high-temperature environment, and in a high-humidity environment, the outermost surface of the photoreceptor surface tends to adhere to the support surface. is there. On the other hand, if it exceeds 10% by mass, it can be used as a lithographic printing plate material, but in the high humidity environment, the outermost surface of the photoreceptor surface tends to adhere to the support surface. The addition amount is particularly preferably 0.1 to 5% by mass.

  Next, typical compound examples that can be used in the present invention include the following.

Y1: C ₁₇ H ₃₅ COOH glycerol monoester Y2: C ₁₇ H ₃₅ COOH diglycerol monoester Y3: C ₁₃ H ₂₇ COOH glycerol monoester Y4: C ₁₃ H ₂₇ COOH triglycerol monoester Y5: C ₁₇ H ₃₅ COOH pentaerthritol mono (di) ester [support for photosensitive lithographic printing plate material]
The support that can be used in the photosensitive lithographic printing plate material of the present invention is preferably an aluminum plate. In this case, a pure aluminum plate, an aluminum alloy plate, or the like may be used.

  Various aluminum alloys can be used as the support, such as alloys of aluminum and metals such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, titanium, sodium, iron, etc. Aluminum plates manufactured by various rolling methods can be used. In addition, a recycled aluminum plate obtained by rolling recycled aluminum ingots such as scrap materials and recycled materials that are becoming popular in recent years can also be used.

  The support that can be used in the photosensitive lithographic printing plate material of the present invention and the image forming method of the present invention is subjected to a degreasing treatment to remove surface rolling oil prior to roughening (graining treatment). It is preferable. 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. It is preferable to perform the treatment.

  Examples of the method for roughening the surface of the support 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, for example, by rotating a rotating brush using a bristle having a diameter of 0.2 to 0.8 mm, and for example, volcanic ash particles having a particle size of 10 to 100 μm on water. While supplying the uniformly dispersed slurry, the brush can be pressed. The roughening by honing polishing is performed by, for example, uniformly dispersing volcanic ash particles having a particle size of 10 to 100 μm in water, injecting pressure from a nozzle, and causing the surface to collide obliquely with the support surface. Can do. Further, for example, abrasive particles having a particle size of 10 to 100 μm are applied to the support surface so as to be present at a density of 2.5 × 10 ³ to 10 × 10 ³ particles / cm ² at intervals of 100 to 200 μm. Roughening can also be performed by laminating the sheets and applying a pressure to transfer the rough surface pattern of the sheet.

After the surface is roughened by the mechanical surface 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 support, 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 neutralize 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 50V, but is preferably selected from the range of 10 to 30V. 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 electrolytic solution as an electrolytic solution, it can be generally performed by applying a voltage in the range of 1 to 50V, but it is selected from the range of 10 to 30V. preferable. 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 50V, but is preferably selected from the range of 2 to 30V. 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 100~2000C / dm ^2, and more 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. 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.

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 roughening, or the mechanical surface roughening treatment method followed by the electrochemical surface roughening method may be used for roughening. You may face it.

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. For the anodizing treatment, a method of electrolyzing an aqueous solution containing sulfuric acid and / or phosphoric acid at a concentration of 10 to 50% as an electrolytic solution at a current density of 1 to 10 A / dm ² is preferably used. The method of electrolyzing at high current density in sulfuric acid described in Japanese Patent No. 1,412,768, the method of electrolyzing using phosphoric acid described in Japanese Patent No. 3,511,661, chromic acid, Examples thereof include a method using a solution containing one or more acids, malonic acids and the like. The formed anodic oxidation coating amount is suitably 1 to 50 mg / dm ² , preferably 10 to 40 mg / dm ² . The anodized coating amount is obtained by, for example, immersing an aluminum plate in a chromic phosphate solution (85% phosphoric acid solution: 35 ml, prepared by dissolving 20 g of chromium (IV) oxide in 1 L of water) to dissolve the oxide film, It is obtained from mass change measurement before and after dissolution of the coating on the plate.

  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, in this invention, after performing these processes, the process which coat | covers a support body surface with polyvinylphosphonic acid can be performed. The coating treatment is not limited to a coating method, a spray method, a dip method, or the like, but a dip method is suitable for making the equipment inexpensive.

  In the case of a dip type, it is preferable to treat polyvinylphosphonic acid with a 0.01 to 35% aqueous solution, and a 0.1 to 5% aqueous solution is particularly preferable. The treatment temperature is preferably 20 ° C or higher and 90 ° C or lower, and more preferably 40 ° C or higher and 80 ° C or lower. If it is lower than 20 ° C., printing stains are bad, and if it is higher than 90 ° C., printing durability is deteriorated.

  The treatment time is preferably 10 to 180 seconds. After the treatment, it is preferable to perform a squeegee treatment or a water washing treatment in order to remove the excessively laminated polyvinylphosphonic acid. Furthermore, it is preferable to perform a drying process. As a drying temperature, 20-95 degreeC is preferable.

The amount of polyvinylphosphonic acid applied to the surface of the aluminum support of the present invention is preferably 3 to ²⁰ mg / m2. Particularly, 4 to 15 mg / m ² is preferable. If it is less than 3 mg / m ² , printing stains in the non-image area will occur, and if it exceeds 20 mg, the printing durability will deteriorate.

  Various concentrations of polyvinylphosphonic acid aqueous solution concentration, treatment temperature, and treatment time can be combined to obtain a desired coating amount.

  The surface phosphorus atom concentration (atm%) in the state where the surface of the aluminum support of the present invention is coated with polyvinyl sulfonic acid is preferably 3 to 15 atm%. Particularly preferred is 5 to 9 atm%.

(Polymer binder)
The photosensitive lithographic printing plate material used in the present invention contains a polymer binder in the photopolymerizable photosensitive layer.

  Examples of the polymer binder used in the present invention include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, and others. 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 preferred.

  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.

  Furthermore, the polymer binder of this invention can use the monomer etc. as described in following (1)-(14) as another copolymerization monomer.

  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, 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. Are also preferred as polymer binders.

  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.

  These copolymers preferably have a weight average molecular weight of 1 to 200,000 as measured by gel permeation chromatography (GPC), but are not limited to this range.

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

  Furthermore, the acid value of the resin is preferably used in the range of 10 to 150, more preferably in the range of 30 to 120, and the use in the range of 50 to 90 from the viewpoint of balancing the polarity of the entire photosensitive layer. Particularly preferred, this can prevent pigment aggregation in the photosensitive layer coating solution.

[Monomer having an ethylenically unsaturated bond capable of addition polymerization]
These compounds having addition-polymerizable ethylenically unsaturated bonds according to the present invention include general radical-polymerizable monomers and ethylenic two-molecules that can be addition-polymerized in a molecule generally used for ultraviolet curable resins. Polyfunctional monomers having a plurality of heavy bonds and polyfunctional oligomers can be used.

  The compound is not limited, but preferred examples include 2-ethylhexyl acrylate, 2-hydroxypropyl acrylate, glycerol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate, tetrahydrofurfuryloxyethyl acrylate, tetrahydro Furfuryloxyhexanolide acrylate, acrylate of ε-caprolactone adduct of 1,3-dioxane alcohol, monofunctional acrylic acid esters such as 1,3-dioxolane acrylate, or these acrylates as methacrylate, itaconate, crotonate, maleate Methacrylic acid, itaconic acid, crotonic acid, maleic acid esters such as ethylene glycol diacrylate , Triethylene glycol diacrylate, pentaerythritol diacrylate, hydroquinone diacrylate, resorcin diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, dipentylate of hydroxypentylate 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, Ε-caprolactone adduct of 3-dioxane diacrylate, tricyclodecane dimethylol acrylate, tricyclodecane dimethylol acrylate Difunctional acrylic acid esters such as diglycidyl ether diacrylate of 1,6-hexanediol, or methacrylic acid, itaconic acid, crotonic acid, maleic acid ester in which these acrylates are replaced with methacrylate, itaconate, crotonate, maleate, For example, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, dipentaerythritol Ε-caprolactone adduct of hexaacrylate, pyrogallol triacrylate Polyfunctional acrylic acid esters such as propionic acid / dipentaerythritol triacrylate, propionic acid / dipentaerythritol tetraacrylate, hydroxypivalylaldehyde-modified dimethylolpropane triacrylate, or these acrylates with methacrylate, itaconate, crotonate, Examples thereof include methacrylic acid, itaconic acid, crotonic acid, and maleic acid ester instead of 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 alone 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 composition of the present invention includes phosphazene monomer, triethylene glycol, isocyanuric acid EO (ethylene oxide) modified diacrylate, isocyanuric acid EO modified triacrylate, dimethylol tricyclodecane diacrylate, trimethylolpropane benzoic acid benzoate. Addition-polymerizable oligomers and prepolymers having monomers such as acid 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 present invention, it is preferable to use an addition-polymerizable ethylenic double bond-containing monomer containing a tertiary amino group in the molecule. 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, collectable compounds described in JP-A-1-165613, JP-A-1-203413, and JP-A-1-197213 are preferably used.

  Furthermore, the present invention uses a reaction product of 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. Is preferred.

  Examples of the polyhydric alcohol containing 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 an ethylenic double bond capable of addition polymerization with a hydroxyl group in the molecule include compounds such as MH-1 to MH-13, but are not limited thereto. Preferable examples include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxypropylene-1,3-dimethacrylate, 2-hydroxypropylene-1-methacrylate-3-acrylate, and the like.

  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.

  Specific examples of reaction products of polyhydric alcohols containing tertiary amino groups in the molecule, diisocyanate compounds, and compounds containing ethylenic double bonds capable of addition polymerization with hydroxyl groups in the molecule are shown below. Shown in

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.

[Sensitizing dye]
When laser light is used as the light source, a sensitizing dye is preferably added to the photosensitive layer. It is preferable to use a dye having an absorption maximum wavelength in the vicinity of the wavelength of the light source.

  Compounds that sensitize wavelengths from visible light to near infrared, that is, dyes having an absorption maximum between 350 nm and 1300 nm include, for example, cyanine, phthalocyanine, merocyanine, porphyrin, spiro compounds, ferrocene, fluorene, fulgide, imidazole, and perylene. , Phenazine, phenothiazine, polyene, xanthene, azo compound, diphenylmethane, triphenylmethane, polymethine acridine, coumarin, coumarin derivative, ketocoumarin, quinacridone, indigo, styryl, pyrylium compound, pyromethene compound, pyrazolotriazole compound, benzothiazole compound, barbi Examples thereof include ketoalcohol borate complexes such as tool acid derivatives and thiobarbituric acid derivatives, and further include European Patent No. 568,993 and US Patent No. 4,508. 811 No., 5,227,227 JP, JP 2001-125255, compounds described in JP-A 11-271969 Patent etc. are also used.

  Specific examples of the combination of the photopolymerization initiator and the sensitizing dye include combinations described in JP-A Nos. 2001-125255 and 11-271969.

  Further, when recording is performed using a semiconductor laser having a light emission wavelength in the range of 380 nm to 430 nm, that is, a so-called violet laser as a laser beam of the light source, it is desirable to include a dye having an absorption maximum between 350 nm and 450 nm. The dye having an absorption maximum between 350 nm and 450 nm is not particularly limited in terms of structure, but the cyanine, phthalocyanine, merocyanine, porphyrin, spiro compound, ferrocene, fluorene, fulgide, imidazole, perylene, phenazine, phenothiazine, Polyene, azo compound, diphenylmethane, triphenylmethane, polymethine acridine, coumarin, coumarin derivative, ketocoumarin, quinacridone, indigo, styryl, pyrylium compound, pyromethene compound, pyrazolotriazole compound, benzothiazole compound, barbituric acid derivative, thiobarbitur tool Any dye group such as an acid derivative and a keto alcohol borate complex can be used as long as the absorption maximum satisfies the requirement. Specifically, Japanese Patent Application Laid-Open Nos. 2002-296664, 2002-268239, 2002-268238, 2002-268204, 2002-221790, 2002-202598, 2001 The dyes described in JP-A-042525, JP-A-2000-309724, JP-A-2000-258910, JP-A-2000-206690, JP-A-2000-147763, JP-A-2000-098605 can be used. However, the present invention is not limited to this.

  Although the compounding quantity of these polymerization initiators is not specifically limited, Preferably, it is 0.1-20 mass parts with respect to 100 mass parts of compounds which can be addition-polymerized or bridge | crosslinked. The mixing ratio of the photopolymerization initiator and the sensitizing dye is preferably in the range of 1: 100 to 100: 1 in terms of molar ratio.

  Specifically, it is shown in D-1 to D-8.

(Photopolymerization initiator)
Examples of the photopolymerization initiator of the present invention include titanocene compounds, iron arene complex compounds, trihaloalkyl compounds, and monoalkyltriarylborate compounds.

(Titanocene compound)
The photopolymerization initiator composition of the present invention contains a titanocene compound, and examples thereof include compounds described in JP-A-63-41483 and JP-A-2-291. (Cyclopentadienyl) -Ti-di-chloride, bis (cyclopentadienyl) -Ti-bis-phenyl, bis (cyclopentadienyl) -Ti-bis-2,3,4,5,6-penta Fluorophenyl, 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 (methyl Lopentadienyl) -Ti-bis-2,3,4,5,6-pentafluorophenyl, bis (methylcyclopentadienyl) -Ti-bis-2,3,5,6-tetrafluorophenyl, bis (methylcyclo Pentadienyl) -Ti-bis-2,6-difluorophenyl (IRUGACURE 727L: manufactured by Ciba Specialty Chemicals), bis (cyclopentadienyl) -bis (2,6-difluoro-3- (py-1-yl) ) Phenyl) titanium (IRUGACURE784: manufactured by Ciba Specialty Chemicals), bis (cyclopentadienyl) -bis (2,4,6-trifluoro-3- (pyridin-1-yl) phenyl) titanium bis (cyclopenta) Dienyl) -bis (2,4,6-trifluoro-3- (2-5-dimethylpyri-) - yl) phenyl) titanium, and the like.

  The structures of typical compounds are shown as I-1 and I-2 below.

(Iron arene complex compound)
Examples of the iron arene complex compound include compounds described in JP-A-59-219307. More preferable specific examples include η-benzene- (η-cyclopentadienyl) iron hexafluorophosphate, η-cumene- (η-cyclopentadienyl) iron hexafluorophosphate, η-fluorene- (η-cyclopenta Dienyl) iron hexafluorophosphate, η-naphthalene- (η-cyclopentadienyl) iron hexafluorophosphate, η-xylene- (η-cyclopentadienyl) iron hexafluorophosphate, η-benzene- (η-cyclo Pentadienyl) iron tetrafluoroborate and the like.

  The structure of a typical compound is shown as I-3 below.

(Monoalkyl aryl borate compound)
Examples of the monoalkyl triaryl borate compound include compounds described in JP-A-62-154024 and JP-A-62-143044, and more preferable specific examples include tetra-n-butylammonium n-butylate. Rootlinaphthalen-1-yl-borate, tetra-n-butylammonium n-butyl-triphenyl-borate, tetra-n-butylammonium n-butyl-tri- (4-tert-butylphenyl) -borate, tetra-n- Examples include butyl ammonium n-hexyl root- (3-chloro-4-methylphenyl) -borate and tetra-n-butyl ammonium n-hexyl root- (3-fluorophenyl) -borate.

(Trihaloalkyl compound)
The photosensitive composition and photosensitive lithographic printing plate material of the present invention contain a compound containing a photodegradable trihaloalkyl group known as a free radical forming photoinitiator for a photopolymerizable mixture. As this type of combination initiator, compounds containing chlorine and bromine as halogen are particularly suitable. The trihaloalkyl group is preferably a trihalomethyl group, and is preferably bonded to an aromatic carbocycle or a heterocycle directly or via a continuously conjugated chain. Compounds having a triazine ring preferably having two trihalomethyl groups as a mother nucleus, especially compounds described in EP-A-137 452, DE-A-21 18 259 and 22 43 621 Is preferred. These compounds exhibit strong light absorption in the near ultraviolet region, for example, 350 to 400 nm. Combination initiators that do not absorb themselves or absorb very little light in the spectral region of the copying light, for example trihalomethyltriazines containing substituents with short electronic systems or aliphatic substituents that allow mesomeries; Is also appropriate. Likewise suitable are compounds having different basic skeletons and absorbing light in the short-wave ultraviolet region, such as phenyl trihalomethyl sulfone or phenyl trihalomethyl ketone, such as phenyl tribromomethyl sulfone.

  Specific examples include CI-1 to CI-3.

  In addition, any photopolymerization 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, the following can be used as a photopolymerization initiator that can be used in combination.

  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 Sho 59-107344 That.

(Oxygen barrier layer)
In the present invention, it is desirable to provide an oxygen blocking layer (overcoat layer) on the uppermost surface of the photosensitive layer.

  For the oxygen barrier layer, a water-soluble polymer capable of forming a film having low oxygen permeability is used. Specifically, it contains polyvinyl alcohol and polyvinyl pyrrolidone. Polyvinyl alcohol has an effect of suppressing permeation of oxygen, and polyvinyl pyrrolidone has an effect of ensuring adhesion with an adjacent photosensitive layer.

  In addition to the above two polymers, polysaccharides, polyethylene glycol, gelatin, glue, casein, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, 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.

  In the lithographic printing plate material of the present invention, the peeling force between the photosensitive layer and the overcoat layer is preferably 35 g / 10 mm or more, more preferably 50 g / 10 mm or more, and further preferably 75 g / 10 mm or more. Preferred overcoat layer compositions include those described in Japanese Patent Application No. 8-161645.

  The peeling force in the present invention is that when an adhesive tape having a predetermined width is applied on the overcoat layer and the adhesive tape is peeled off with the overcoat layer at an angle of 90 degrees with respect to the plane of the planographic printing plate material. The force was measured.

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

  The thickness of the overcoat layer is preferably from 0.1 to 5.0 μm, particularly preferably from 0.5 to 3.0 μm.

[Development solution]
(Alkaline agent)
As the inorganic alkaline agent contained in the developer used in the processing method of the present invention, sodium hydroxide, potassium and lithium are preferably used. These alkali agents are used alone or in combination of two or more.

  The pH is preferably pH 10.5 to 12.7. Particularly preferred is a pH range of 11.0 to 12.5. When the pH of the developer is lower than 10.5, the image portion of the printing plate obtained from the photosensitive lithographic printing plate that can be developed with such a developer is physically fragile, and wear during printing is sufficient Printing durability cannot be obtained. Further, the image portion is chemically weak, and an image of a portion wiped with an ink washing solvent or a plate cleaner is damaged during printing, and as a result, sufficient chemical resistance cannot be obtained. A developer having a high pH such that the pH exceeds 12.7 is strongly irritating when adhering to the skin or mucous membrane, and is not preferable because it requires sufficient care in handling.

  In addition to the alkali agent, it is preferable to contain the following buffering agent in order to have plate surface cleaning properties and developer pH buffering properties. For example, potassium silicate, sodium silicate, lithium silicate, ammonium silicate, metametasilicate, sodium metasilicate, lithium metasilicate, ammonium metasilicate, tripotassium phosphate, trisodium phosphate, trilithium phosphate, triammonium phosphate, dipotassium phosphate, Disodium phosphate, dilithium phosphate, diammonium phosphate, potassium carbonate, sodium carbonate, lithium carbonate, ammonium carbonate, potassium bicarbonate, sodium bicarbonate, lithium bicarbonate, ammonium bicarbonate, potassium borate, sodium borate, lithium borate, boric acid Ammonium is mentioned, and it is preferable to contain at least one compound selected from the above.

Most preferred are potassium silicate and potassium carbonate. The concentration of silicate is preferably 0.5 to 3.5% by mass in terms of SiO ₂ concentration. Further, the concentration of carbonate is preferably 0.5 to 3.5% by mass in terms of CO ^{3 −} concentration.

  Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also used in combination.

  The developer referred to in the present invention is not only an unused solution used at the start of development, but also supplemented with a replenisher in order to correct the activity of the solution that decreases due to the processing of the photosensitive lithographic printing plate, Includes a liquid having a maintained activity (so-called running liquid). The replenisher therefore needs to have a higher activity (alkali concentration) than the developer, so the pH of the replenisher may exceed 13.0.

(Surfactant)
As the surfactant used in the present invention, it is essential to use at least one surfactant represented by Compound A, Compound B, and Compound C, anionic and nonionic polymer surfactant. In addition, it is possible to achieve both the stain during printing and the printing durability without impairing the image formability, and excellent processing stability.

  Compound A is an anionic surfactant containing a polyoxyalkylene group characterized in that the molecular weight of the saturated alkyl group in the hydrophobic group portion is 25% or less of the molecular weight of the entire hydrophobic group, and is a water-insoluble photosensitive compound. In order to stably disperse and solubilize the layer composition for a long period of time, it is preferable to have a polyoxyethylene group. In addition, a surfactant having an unsaturated hydrophobic group such as an aryl group is more preferable because the solubilizing power of the dissolved photosensitive layer component is high.

  Specific examples of Compound A include the compounds shown below, but are not limited thereto.

  The following compound B is also a preferred compound.

Compound B R ₁ —O— (C ₃ H ₆ O) _m — (C ₂ H ₄ O) _n —H
The molecular weight of the hydrophobic group portion (R ₁ ) is preferably large to some extent, and preferably 70 or more. Particularly preferred are a naphthyl group, a benzyl group, and an alkyl group having 8 to 12 carbon atoms. If the molecular weight of the hydrophobic group is too large, the solubility of the photosensitive layer is poor and a large amount of sludge is generated.

When this compound is added in a small amount, the solubility of the photosensitive layer is poor and a large amount of sludge is generated. If the amount is too large, the foaming property becomes too large, or the film thickness of the photosensitive layer is reduced. The polyoxypropylene moiety (C ₃ H ₆ O) _n of Compound B is (CH ₂ CH ₂ CH ₂ O) _n , (CH (CH ₂ ) CH ₂ O) _n , (CH ₂ CH (CH ₂ ) O ) Three ways of _n can be considered. Any structure may be used, but the structure of (CH ₂ CH (CH ₂ ) O) _n is most preferable.

  The value of m is most preferably 2-3. The value of n is most preferably 5-30. n / m is most preferably in the range of 5 or more and 20 or less. If each value of m, n, and n / m is too large or too small, the balance between the hydrophilic group and the hydrophobic group of the active agent is lost, and sludge increases and developability deteriorates.

  Specific examples of Compound B include the compounds shown below, but are not limited thereto.

  Compound C is a nonionic surfactant, wherein the molecular weight of the saturated alkyl group in the hydrophobic group portion is 25% or less of the molecular weight of the entire hydrophobic group. If the molecular weight of the saturated alkyl group exceeds 25%, foaming tends to occur and the developing tank is contaminated, which is not preferable. In order to stably disperse and solubilize the water-insoluble photosensitive layer composition for a long period of time, it preferably has a polyoxyethylene group. Further, a surfactant having an unsaturated hydrophobic group such as an aryl group has excellent penetrating power into non-image areas and good developability.

  Specific examples of Compound C include the compounds shown below, but are not limited thereto.

  The nonionic polymer activator is not particularly limited as long as it is a polymer activator containing a polyoxyalkylene group having 2 to 4 carbon atoms. In particular, polyoxyethylene / polyoxypropylene block copolymers or water-soluble polymer surfactants of alkyl-polyoxyalkylene copolymers described in claim 1 of USP-5972572 are preferred. These polymeric surfactants improve the dispersibility of the photosensitive layer components in the developer, and improve the stability of dispersion and solubilization of the components eluted from the photosensitive layer by the amide group-containing surfactant. There is an effect of suppressing reattachment. In particular, when a urethane group-containing monomer is used as a component of the photosensitive layer, this component exhibits an effect of suppressing the precipitation of the component in the developing solution to generate residue and reattachment to the plate.

  The polyoxyethylene / polyoxypropylene block copolymer is represented by the following structural formula.

HO (C ₂ H ₄ O) _a (C ₃ H ₆ O) _b (C ₂ H ₄ O) _c H
In the above formula a. b. c shows the integer of 1-10000. The range of the polymer suitable for the present invention is 10 to 90% by mass, preferably 40 to 60% by mass of ethylene oxide in the total molecule, and the molecular weight of polyoxypropylene is in the range of 1000 to 4000, preferably 2000 to 3500. Is particularly good.

  In the present invention, the polyoxyalkylene-containing polymeric surfactant is used in a mixed system with an amide group-containing surfactant, and may contain other active agents. The addition amount of each activator is preferably in the range of 0.5 to 5.0% by mass of the total amount of the developer, and particularly preferably 1 to 3% by mass.

  The anionic polymer activator has an effect of suppressing reattachment of components eluted from the photosensitive layer to the plate by improving the dispersibility of the photosensitive layer component in the developer. In particular, when a urethane group-containing monomer is used as a component of the photosensitive layer, this component exerts a great effect in suppressing the deposition of the component in the developing solution to cause residue and reattachment to the plate. As the polymer having a carboxyl group used in the present invention, a polymer having at least a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2) is preferably used.

In the formulas (1) and (2), R ₁ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In the formula (1), A represents a hydrogen atom or a carboxyl group. X ⁺ represents a potassium ion, a sodium ion, or an ammonium ion. (2) B in the formula is —COOR ₂ , —CONHR ₂ , an aromatic hydrocarbon group having 6 to 15 carbon atoms which may have a substituent (the substituent is an alkyl group having 1 to 20 carbon atoms, Br Halogen atoms such as Cl, I, aromatic hydrocarbon groups having 6 to 15 carbon atoms, aralkyl groups having 7 to 17 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, alkoxy-carbonyl groups having 2 to 20 carbon atoms, And an acyl group having 2 to 15 carbon atoms). R ₂ may have a substituent having 1 to 10 carbon atoms, an alkyl group having 1 to 20 carbon atoms (the same as the above-mentioned substituent), and an aromatic carbon atom having 6 to 15 carbon atoms that may have a substituent. A hydrogen group (the substituent is the same as above) and an allyl group are shown.

  As long as it is a high molecular weight activator containing the structural unit, it may be a unipolymer, a k-binary copolymer, a ternary copolymer, a quaternary copolymer, or a quaternary copolymer. It preferably has a molecular weight and an acid value. The weight average molecular weight is preferably 5,000 to 300,000, more preferably 5,000 to 50,000. In the present invention, the carboxyl group-containing polymer is used in a complex system with an amide group-containing nonionic surfactant or an amide group-containing anion surfactant, and 0.5 to 5.0% by mass in an aqueous alkaline solution. The addition of 1 to 3% by mass is effective. If the amount is less than the above range, the effect of suppressing development residue is small, and if the amount is too large, a problem of precipitation of the polymer itself occurs.

  In addition, the developer used in the present invention includes not only the compound A, compound B, compound C, nonionic polymer surfactant and anionic polymer surfactant, but also promotes developability and disperses development residue. Various surfactants may be added for the purpose of improving the ink affinity of the printing plate image area.

  Surfactants include anionic, cationic, nonionic and amphoteric surfactants. Examples include polyoxyethylene alkyl ethers, polyoxyethylene aryl ethers, polyoxyethylene naphthyl ethers, polyoxyethylene polyoxyethylenes. Styryl phenyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol Fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene glycol Phosphorus fatty acid partial esters, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene-polyoxypropylene block copolymer adduct of ethylenediamine, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamine , Nonionic surfactants such as polyoxyethylene alkylamine, triethanolamine fatty acid ester, trialkylamine oxide, fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid ester salts , Linear alkylbenzene sulfonates, branched alkylbenzene sulfonates, alkylnaphthalene sulfonates, polyoxyethylene aryl ether carboxylic acid, polyoxyethylene naphth Ether sulfate, alkyl diphenyl ether sulfonate, alkylphenoxy polyoxyethylene propyl sulfonate, polyoxyethylene alkyl sulfophenyl ether, polyoxyethylene aryl ether sulfate, N-methyl-N-oleyl taurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, fatty acid alkyl ester sulfate ester salt, alkyl sulfate ester salt, polyoxyethylene alkyl ether sulfate ester salt, fatty acid monoglyceride sulfate ester, poly Oxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates , Polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates, partially saponified styrene / maleic anhydride copolymers, partially saponified olefin / maleic anhydride copolymers And anionic surfactants such as naphthalene sulfonate formalin condensates.

  Alkylamine salts, quaternary ammonium salts such as tetrabutylammonium bromide, cationic surfactants such as polyoxyethylene alkylamine salts, polyethylene polyamine derivatives, carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric acid esters And amphoteric surfactants such as imidazolines.

  Among the surfactants listed above, those having polyoxyethylene can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene and polyoxybutylene, and these surfactants are also included.

  Said surfactant can be used individually or in combination of 2 or more types, and is added in 0.05-10 mass% in a developing solution, More preferably, it is added in 0.1-5 mass%.

(Chelating agent)
Examples of chelating agents include polyphosphoric acid and its sodium, potassium and ammonium salts, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminedisuccinic acid, methyliminodiacetic acid, β-alanine diacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid Aminopolycarboxylic acids such as nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid and 1,3-diamino-2-propanoltetraacetic acid and their sodium, potassium and ammonium salts, aminotri (methylenephosphonic acid), ethylenediamine Tetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), triethylenetetraminehexa (methylenephosphonic acid) Hydroxyethyl ethylene diamine tri (methylene phosphonic acid) and 1-hydroxyethane-1,1-diphosphonic acid and their sodium salts, potassium salts and ammonium salts. The optimum value of such a hard water softening agent varies depending on its chelating power, the hardness of the hard water used and the amount of hard water. % By mass, more preferably in the range of 0.01 to 0.5% by mass. If the addition amount is less than this range, the intended purpose is not sufficiently achieved. If the addition amount is more than this range, adverse effects on the image area such as color loss will occur. The remaining component of the developer and replenisher is water.

[Automatic processor]
The automatic developing machine used in the present invention is preferably provided with a mechanism for automatically replenishing a replenisher with a necessary amount in a developing bath, and preferably provided with a mechanism for discharging a developer exceeding a certain amount, Preferably, a mechanism for automatically replenishing a required amount of water to the developing bath is provided, preferably a mechanism for detecting plate passing is provided, and preferably the processing area of the plate based on detection of plate passing A mechanism for controlling the replenishment amount and / or replenishment timing of the replenisher and / or water to be replenished, preferably based on detection of the plate and / or estimation of the processing area. Preferably, a mechanism for controlling the temperature of the developer is provided, preferably a mechanism for detecting the pH and / or conductivity of the developer is provided, preferably the pH of the developer and Or mechanism for controlling the replenishment amount and / or replenishment timing of replenishment solution and / or water attempts to replenish based on conductivity is imparted. Moreover, when there exists a washing process after a image development process, the washing water after use can be used as a dilution water of the concentrate of a development concentrate and a development replenisher.
The automatic processor used in the present invention may have a pretreatment unit that immerses the plate in the pretreatment liquid before the development step. The pretreatment unit is preferably provided with a mechanism for spraying the pretreatment liquid onto the plate surface, and preferably provided with a mechanism for controlling the temperature of the pretreatment liquid to an arbitrary temperature of 25 ° C to 55 ° C. Preferably, a mechanism for rubbing the plate surface with a roller-like brush is provided. Moreover, water etc. are used as this pretreatment liquid.

[Post-processing]
The plate developed with the developer having such a composition is subjected to post-processing with washing water, a rinsing solution containing a surfactant, a finisher mainly composed of gum arabic or starch derivatives, or a protective gum solution. In the post-treatment of the photopolymerization type photosensitive printing plate of the present invention, these treatments can be used in various combinations, for example, after development → washing → rinsing solution containing a surfactant or development → water washing → finisher The treatment with the liquid is preferable because the rinse liquid and the finisher liquid are less fatigued. Furthermore, a countercurrent multistage process using a rinse liquid or a finisher liquid is also a preferred embodiment. These post-processing are generally performed using an automatic developing machine including a developing unit and a post-processing unit. As the post-treatment liquid, a method of spraying from a spray nozzle or a method of immersing and conveying in a treatment tank filled with the treatment liquid is used. There is also known a method in which a small amount of washing water after development is supplied to the plate surface and washed, and the waste solution is reused as dilution water for the developer stock solution. In such automatic processing, processing can be performed while each replenisher is replenished with each replenisher according to the processing amount, operating time, and the like. In addition, a so-called disposable processing method in which treatment is performed with a substantially unused post-treatment liquid can also be applied. The lithographic printing plate obtained by such processing is loaded on an offset printing machine and used for printing a large number of sheets.

[Gum solution]
It is preferable to add an acid or a buffering agent to the gum solution in order to remove alkali components from the developer, and in addition, a hydrophilic polymer compound, a chelating agent, a lubricant, a preservative, a solubilizing agent, and the like can be added. When the gum solution contains a hydrophilic polymer compound, it also has a function as a protective agent for preventing scratches and stains on the developed plate.

  By adding a surfactant to the gum solution used in the present invention, the surface state of the coating layer is improved. Surfactants that can be used include anionic surfactants and / or nonionic surfactants. 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 aryl ethers, polyoxyethylene naphthyl ether, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxypropylene alkyl ether, glycerin fatty acid partial ester. , Sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters , Polyglycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid part Esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides and the like. Of these, polyoxyethylene alkylphenyl ethers, polyoxyethylene-polyoxypropylene block polymers and the like are preferably used. Fluorine-based and silicon-based anions and nonionic surfactants can also be used. 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.

  In the gum solution used in the present invention, polyhydric alcohols, alcohols and aliphatic hydrocarbons can be used as lubricants as necessary in addition to the above components.

  Among the polyhydric alcohols, preferred specific examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, sorbitol and the like. Examples of the alcohol include propyl alcohol, butyl alcohol, and pen. Examples include alkyl alcohols such as tanol, hexanol, heptanol, and octanol, and alcohols having an aromatic ring such as pendyl alcohol, phenoxyethanol, and phenylaminoethyl alcohol.

  Examples of the aliphatic hydrocarbon include n-hexanol, methyl amyl alcohol, 2-ethylbutanol, n-heptanol, 3-heptanol, 2-octanol, 2-ethylhexanol, nonanol, 3,5,5-trimethylhexanol, n-decanol, undecanol, n-dodecanol, trimethylnonyl alcohol, tetradecanol, heptadecanol, 2-ethyl-1,3-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 2,4 -Hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and the like. The content of these lubricants is suitably 0.1 to 50% by mass, more preferably 0.5 to 3.0% by mass in the composition.

  In addition to the above components, ethylene glycol, propylene glycol, triethylene glycol, butylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, diglycerin and the like are suitably used as a lubricant if necessary. These wetting agents may be used alone or in combination of two or more. In general, the wetting agent is preferably used in an amount of 1 to 25% by weight.

  Various hydrophilic polymers can be contained for the purpose of improving the film-forming property.

  As such a hydrophilic polymer, any hydrophilic polymer that can be conventionally used in a gum solution can be preferably used. For example, gum arabic, fiber derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose etc.) and modified products thereof, polyvinyl alcohol and derivatives thereof, polyvinylpyrrolidone, polyacrylamide and copolymers thereof, vinyl methyl ether / maleic anhydride copolymer Examples thereof include a polymer, a vinyl acetate / maleic anhydride copolymer, and a styrene / maleic anhydride copolymer.

  In general, the gum solution used in the present invention is more advantageously used in the acidic range of pH 3 to 6. In order to adjust the pH to 3 to 6, it is generally adjusted by adding a mineral acid, an organic acid, an inorganic salt, or the like in the post-treatment liquid. 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.

  A preservative, an antifoaming agent, etc. can be added to the gum solution used in the present invention.

For example, as a preservative, phenol or a derivative thereof, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, benzoisothiazolin-3-one, benztriazole derivative, amiding anidine derivative, quaternary ammonium salt, pyridine, Examples thereof include derivatives such as quinoline and guanidine, diazine, triazole derivatives, oxazole, and oxazine derivatives. 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 to 1.0% by mass with respect to the gum solution at the time of use 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 mass% with respect to the gum solution at the time of use.
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.

  In addition, 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 of the gum, and a more preferable range is 0.05 to 5% by mass.

  The sensitizers as described above may be prepared by emulsifying and dispersing the gum as an oil phase, or may be solubilized with the help of a solubilizer.

In the present invention, the solid content concentration of the gum solution is preferably 5 to 30 g / l. The film thickness of the gum can be controlled by the conditions of the squeeze means of the automatic machine. In the present invention, the gum application amount is preferably 1 to 10 g / m2. If the amount of gum application exceeds 10, the plate surface needs to be very hot in order to dry in a short time, which is disadvantageous in terms of cost and safety, and the effects of the present invention cannot be sufficiently obtained. If it is less than 1 g / m ² , uniform coating becomes difficult and stable processability cannot be obtained.

  In the present invention, the time from the end of the application of the gum solution to the start of drying is preferably 3 seconds or less. More preferably, it is 2 seconds or less, and the shorter the time is, the better the ink deposition property is.

  In the present invention, the drying time is preferably 1 to 5 seconds. When the drying time is 5 seconds or more, the effect of the present invention cannot be obtained. When the drying time is 1 second or less, it is necessary to make the plate surface very hot in order to sufficiently dry the photosensitive lithographic printing plate, which is not preferable in terms of safety and cost.

  In the present invention, as a drying method, a known drying method such as a warm air heater or a far infrared heater can be used.

  In the drying step, the solvent in the gum solution needs to be dried. Therefore, it is necessary to ensure sufficient drying temperature and heater capacity. The temperature required for drying varies depending on the components of the gum solution, but in the case of a gum solution in which the solvent is water, the drying temperature is preferably 55 ° C. or higher. The heater capacity is often more important than the drying temperature, and the capacity is preferably 2.6 kW or more in the case of the hot air drying method. The larger the capacity, the better, but 2.6-7 kW is preferable in terms of balance with cost.

[Washing water before development]
In the present invention, the washing liquid used in the washing step before development is usually water, but the following additives can be added as necessary.

  As the chelating agent, a compound that forms a chelate compound by coordination with a metal ion is used. Ethylenediaminetetraacetic acid, its potassium salt, its sodium salt, ethylenediaminedisuccinic acid, its potassium salt, its sodium salt, triethylenetetramine hexaacetic acid, its potassium salt, its sodium salt, diethylenetriaminepentaacetic acid, its potassium salt, its sodium salt Hydroxyethylethylenediaminetriacetic acid, potassium salt thereof, sodium salt thereof, nitriotriacetic acid, potassium salt thereof, sodium salt thereof, 1-hydroxyethane-1,1-diphosphonic acid, potassium salt thereof, sodium salt thereof, aminotri (methylenephosphone) Acid), potassium salt thereof, sodium salt thereof, phosphonoalkanetricarboxylic acid, ethylenediamine disuccinic acid, potassium salt thereof, sodium salt thereof and the like. Those chelating agents having an organic amine salt instead of the potassium salt and sodium salt are also effective.

  The addition amount of the chelating agent is suitably in the range of 0 to 3.0% by mass.

  As the surfactant, any of anionic, nonionic, cationic and amphoteric surfactants can be used, and anionic or nonionic surfactants are preferred. The type of the preferred surfactant varies depending on the composition of the overcoat layer and the photosensitive layer and generally serves as a dissolution accelerator for the overcoat layer material, and preferably has a low solubility for the photosensitive layer components.

  Examples of anionic surfactants include fatty acid salts, abichenates, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropylsulfonates , Polyoxyethylene alkylsulfophenyl ether salts, sodium N-methyl-N-oleyl taurate, disodium N-alkylsulfosuccinic acid monoamide, petroleum sulfonates, sulfated castor oil, sulfated beef oil, fatty acid alkyl esters Sulfuric acid ester salts, alkyl sulfuric acid ester salts, polyoxyethylene alkyl ether sulfuric acid ester salts, fatty acid monoglyceride sulfuric acid ester salts, polyoxyethylene styrylpheny Ether sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, polyoxyethylene alkyl phenyl ether phosphate ester salt, partially saponified styrene-maleic anhydride copolymer, olefin-maleic anhydride copolymer And partially saponified products, naphthalenesulfonate formalin condensates and the like.

  Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters , Propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, iethylene glycol fatty acid ester, polyiglycerin fatty acid partial ester, polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid moiety Esters, fatty acid diethanolamides, N, N-bis-hydroxyalkylamines, polyoxyethylene alkylamines, trietas Ruamin fatty acid esters, trialkylamine oxides and the like.

  A preferable addition amount of the surfactant is 0 to 10% by mass. Further, an antifoaming agent can be used in combination with the surfactant.

  Examples of preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzoisothiazolin-3-one, benzotriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, pyrozine, Examples include quinoline and guanidine derivatives, diazine, triazole derivatives, oxazole and oxazine derivatives.

  In the cleaning method of the present invention, the cleaning solution used for cleaning before development is preferably used with the temperature adjusted, and the temperature is preferably in the range of 10 to 60 ° C. As a cleaning method, known processing liquid supply techniques such as spraying, dipping, and coating can be used, and processing promoting means such as a brush, a drawing roll, and a submerged shower in the dip processing can be used as appropriate.

  In the present invention, the development treatment may be performed immediately after completion of the pre-development washing step, or the development treatment may be performed after drying before the pre-development washing step. After the development step, known post-treatments such as washing with water, rinsing and gumming can be performed. The pre-development rinse water that has been used once or more can be reused in post-development rinse water, rinse solution, or gum solution.

[Printing ink]
As environmentally friendly printing inks that can be used in the present invention, soybean oil ink “Naturalis 100” manufactured by Dainippon Ink and Chemicals, VOC zero ink “TK Hi-Echo SOY1” manufactured by Toyo Ink, Tokyo Ink Process ink "Soy Servo".

  Although a synthesis example, a support preparation example, and an example are specifically shown below, embodiments of the present invention are not limited thereto. In the examples, “parts” represents “parts by mass” unless otherwise specified.

[Example 1]
(Binder synthesis)
In a three-necked flask under a nitrogen stream, 30 parts of methacrylic acid, 50 parts of methyl methacrylate, 20 parts of ethyl methacrylate, 500 parts of isopropyl alcohol and 3 parts of α, α'-azobisisobutyronitrile are placed in a nitrogen stream. The mixture was reacted for 6 hours in an oil bath at 0 ° C. Then, after refluxing at the boiling point of isopropyl alcohol for 1 hour, 3 parts of triethylammonium chloride and 25 parts of glycidyl methacrylate were added and reacted for 3 hours to obtain an acrylic copolymer 1. The weight average molecular weight measured using GPC was about 35,000, and the glass transition temperature (Tg) measured using DSC (differential thermal analysis) was about 85 ° C.
(Production of support)
An aluminum plate (material 1050, tempered H16) having a thickness of 0.3 mm was immersed in a 5% aqueous sodium hydroxide solution maintained at 65 ° C., degreased for 1 minute, and then washed with water. This degreased aluminum plate was neutralized by dipping in a 10% aqueous hydrochloric acid solution maintained at 25 ° C. for 1 minute, and then washed with water.

Next, the aluminum plate was subjected to electrolytic surface roughening with an alternating current for 60 seconds under conditions of 25 ° C. and a current density of 100 A / dm ^{2 in} a 0.3% by mass nitric acid aqueous solution, and then kept at 60 ° C. Desmutting treatment was performed for 10 seconds in a 5% aqueous sodium hydroxide solution. The surface-roughened aluminum plate subjected to desmut treatment was anodized in a 15% sulfuric acid solution at 25 ° C., a current density of 10 A / dm ² , and a voltage of 15 V for 1 minute. Furthermore, after the anodic acid value treatment, a surface treatment was performed in a polyvinyl phosphonic acid aqueous solution at 75 ° C. for 20 seconds to prepare a support. The dry weight of polyvinylphosphonic acid was 8 mg / m ² , and the center line average roughness (Ra) of the surface was 0.65 μm.

(Preparation of photosensitive lithographic printing plate materials 1-12)
On the support, a photopolymerizable photosensitive layer coating solution having the following composition was prepared as shown in Table 1, and applied with a wire bar so as to be 1.6 g / m ² when dried, and then at 95 ° C. for 1.5 minutes. It dried and obtained the photopolymerization photosensitive layer application | coating samples 1-11.

<Photopolymerization photosensitive layer coating solution>
Monomer 1 (M-3) having addition-polymerizable ethylenic double bond 30.6 parts Monomer 2 having addition-polymerizable ethylenic double bond (NK ester 4G: polyethylene manufactured by Shin-Nakamura Chemical Co., Ltd.) Glycol dimethacrylate) 17.6 parts Photopolymerization initiator (I-1) 2.9 parts Trihaloalkyl compound (CI-1) 1.5 parts Sensitizing dye (D-1) 4.0 parts Acrylic copolymer 1 Listed in Table 1 Thermomeltable Compound Listed in Table 1 N-Phenylglycine benzyl ester 0.3 part Phthalocyanine pigment (MHI454: manufactured by Gokoku Color Co., Ltd.) 3.5 parts 2-t-butyl-6- (3-t- Butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (Sumilyzer GS: manufactured by Sumitomo 3M) 0.1 part Fluorosurfactant (F-178K; manufactured by Dainippon Ink & Co.) 0 To prepare a photopolymerizable photosensitive layer coating solution by diluting 1 part of the photosensitive layer composition in the following organic solvent.

Tyl ethyl ketone 80 parts Cyclohexanone 820 parts M-3: Nn-butyldiethanolamine (1 mol), 1,3-bis (1-isocyanato-1-methylethyl) benzene (2 mol), 2-hydroxypropylene- Reaction product of 1-methacrylate-3-acrylate (2 mol)

Y6: Ester of C ₁₇ H ₃₅ COOH and C ₁₈ H ₃₆ OH Y7: Tetraglycerin monoester of C ₁₃ H ₂₇ COOH On the photopolymerized photosensitive layer coating sample, an oxygen barrier layer coating solution having the following composition was dried. The photosensitive lithographic printing plate materials 1 to 12 having an oxygen blocking layer on the photopolymerized photosensitive layer were prepared by applying with an applicator so as to be 0.8 g / m ² and drying at 65 ° C. for 1.5 minutes. The produced photosensitive lithographic printing plate material was deposited and packaged so that the outermost surface of the photosensitive layer surface and the support surface opposite to the photosensitive layer surface were in contact.

<Oxygen barrier coating solution>
Polyvinyl alcohol (GL-05: manufactured by Nippon Synthetic Chemical Co., Ltd.) 70.0 parts Polyvinylpyrrolidone (K-30: manufactured by BAFS) 29.5 parts Surfactant (Surfinol 465: manufactured by Nissin Chemical Industry Co., Ltd.) 0.5 900 parts water (image formation)
About the photosensitive lithographic printing plate material produced and packed as described above, the area ratio of the image portion and the non-image portion is 1 using a CTP exposure apparatus (Tigercat: manufactured by ECRM) equipped with an FD-YAG laser light source. : Exposure energy: 150 μJ / cm ² , and image exposure at a resolution of 2400 dpi (dots per 2.54 cm) (exposure pattern is 100% image area and 175 LPI 98, 96, 94, 92, 90, 88, 86, 84, 82, 80, 70, 60, 50, 40, 30, 20, 18, 16, 14, 12, 10, 8, 6, 5, 4, 3, 2, 1% square Dot was used).

  Next, before development, a heating unit, a pre-water washing part for removing the oxygen blocking layer, a development part filled with the following developer composition, a water washing part for removing the developer adhering to the plate surface, and a gum solution for protecting the image line part Development processing was performed with a CTP automatic developing machine (PHW23-V: manufactured by Technigraph) equipped with (GW-3: manufactured by Mitsubishi Chemical Co., Ltd.), and lithographic printing plates 1 to 11 were obtained. At this time, the heating unit was set so that the plate surface temperature was 115 ° C. and the plate staying time was 15 seconds. The plate was inserted into the heating device of the self-machine after the exposure was completed within 60 seconds.

<< Developer composition (aqueous solution containing the following additives) >>
Potassium silicate aqueous solution (SiO ₂ : 26%, K ₂ O: 13.5%) 40.0 g / L
Potassium hydroxide 4.0g / L
Ethylenediaminetetraacetic acid 0.5g / L
Polyoxyethylene (13) naphthyl ether sulfonate 20.0 g / L
1 L with water. The pH was 12.1.

(Halftone dot reproducibility)
Highlights (1 to 10%) and shadows (80 to 99%) of lithographic printing plates obtained by the above image forming method were observed with a loupe.

The highlight area is better as small halftone dots are reproduced (displayed as “%” in Table 2).
The shadow area is better as the larger halftone dot is reproduced (indicated by “%” in Table 2).
(Dirty)
A lithographic printing plate produced by exposing and developing a 175-line image on a photosensitive lithographic printing plate material at an exposure amount of 150 μJ / cm ² is applied to a coated paper, printing ink (by DAIYA1F-1 manufactured by Mitsubishi Heavy Industries). Soybean oil ink Naturalis 100: manufactured by Dainippon Ink & Chemicals, Inc.) and fountain solution (H liquid SG-51, concentration 1.5%: manufactured by Tokyo Ink Co., Ltd.) are used, and the presence or absence of background stains is used as an index. Show. It means that the one with no dirt is good.

  In addition, the photosensitive lithographic printing plate material before exposure / development processing is completely shielded from light, stored at a high temperature of 55 ° C./20% RH for 5 days (DT-5), and 40 ° C./80% RH. After storing for 5 days (HT-5) under high humidity conditions, printing is performed under the same conditions as above, and the presence or absence of scumming on the non-image area due to storage is indicated as an index of stain resistance. It means that the one with no dirt is good.

◯: No stain Δ: Slight ink stains can be confirmed by observing with a magnifying glass, but it can be used as a printed product. X: Small ink stains can be confirmed by observing with a loupe. Cannot be used as printed material XX: Ink stains can be confirmed visually and cannot be used as printed material (sticking to the back)
The photosensitive lithographic printing plate material before development, which was deposited and packed so that the outermost surface of the photosensitive layer surface and the support surface were in contact with each other, was allowed to stand for 30 days, and then unpacked and examined for sticking.

  The photosensitive lithographic printing plate material in the present invention is good in all properties, but it is understood that the photosensitive lithographic printing plate material outside the present invention has a problem in any property.

[Example 2]
(Preparation of photosensitive lithographic printing plate materials 13 to 24)
Photosensitive lithographic printing plate materials 13 to 24 having a protective layer on the photosensitive layer were produced in the same manner as in Example 1 except that the photopolymerizable photosensitive layer coating solution was changed to the following and Table 3.

Y6: ester of C ₁₇ H ₃₅ COOH and C ₁₈ H ₃₆ OH Y7: tetraglycerin monoester of C ₁₃ H ₂₇ COOH << photopolymerizable photosensitive layer coating solution >>
Monomer 1 (M-3) having addition-polymerizable ethylenic double bond 30.6 parts Monomer 2 having addition-polymerizable ethylenic double bond (NK ester 4G: Shin-Nakamura Chemical Co., Ltd. polyethylene glycol Dimethacrylate) 17.6 parts Photopolymerization initiator (I-1) 2.9 parts Trihaloalkyl compound (CI-1) 1.5 parts Sensitizing dye (D-5) 4.0 parts Acrylic copolymer 1 Listed in Table 3 Hot-melt compounds Listed in Table 3 N-Phenylglycine benzyl ester 0.3 part Phthalocyanine pigment (MHI454: manufactured by Gokoku Dye) 3.5 parts 2-t-butyl-6- (3-t-butyl 2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (Sumilyzer GS: manufactured by Sumitomo 3M) 0.1 part Fluorine-based surfactant (F-178K; manufactured by Dainippon Ink, Inc.) 0. To prepare a photopolymerizable photosensitive layer coating solution 1 part The photosensitive layer composition is diluted with the following organic solvent.

Tyl ethyl ketone 80 parts Cyclohexanone 820 parts (Image formation)
About the photosensitive lithographic printing plate material produced and packed in this way, using a CTP exposure apparatus (Tiger Cat: modified product manufactured by ECRM) equipped with a laser light source of 408 nm and 30 mW output, The same procedure as in Example 1 was performed except that exposure was performed with an image having an exposure energy of 70 μJ / cm ² and 2400 dpi (number of dots per 2.54 cm) / 175 LPI so that the area ratio was 1: 9.

  The evaluation results are shown in Table 4.

  The photosensitive lithographic printing plate material in the present invention is good in all properties, but it is understood that the photosensitive lithographic printing plate material outside the present invention has a problem in any property.

Claims (4)

Photosensitive having a photosensitive layer comprising a photosensitive composition containing at least a photopolymerization initiator, a polymer binder, a monomer having an addition polymerizable ethylenically unsaturated bond, and a sensitizing dye on a support. In the lithographic printing plate material, the photosensitive layer contains an ester compound of a fatty acid having a melting point of 50 to 120 ° C. and having 12 to 27 carbon atoms and an alcohol having 2 to 5 OH groups. Photosensitive lithographic printing plate material. The photosensitive lithographic printing plate material according to claim 1, comprising 0.1 to 10% by mass of the ester compound. The photosensitive lithographic printing plate material according to claim 1 or 2 is image-exposed with a laser beam of 350 to 600 nm, heated to 90 to 130 ° C, and then contains an inorganic alkaline agent and a surfactant, and has a pH of 10. 5. A method for making a lithographic printing plate, comprising developing with a developer having 5 to 12.7 and an electrical conductivity of 3 to 30 mS / cm. 3. A packing method for stacking photosensitive lithographic printing plate materials according to claim 1 or 2, wherein the stacking is performed so that the outermost surface of the photosensitive layer surface and the support surface opposite to the photosensitive layer surface are in contact with each other.