JP2003233180A - Photosensitive planographic printing plate material and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive planographic printing plate material having good preservation stability, excellent in sensitivity and dot reproducibility and ensuring high image performance and to provide an image forming method. <P>SOLUTION: In the photosensitive planographic printing plate material having on a support at least one photopolymerizable photosensitive layer comprising a monomer containing an addition-polymerizable ethylenically unsaturated bond, a photopolymerization initiator and a polymeric binder, the polymeric binder is a copolymer having a weight average molecular weight (Mw) of 15,000-30,000 and comprising a monomer unit (A) having a carboxyl group and a unit (B) obtained by reacting at least part of the monomer unit having a carboxyl group with an epoxy-containing unsaturated compound as constituent elements, wherein the unit (B) is comprised by 10-30 mol%. The photosensitive planographic printing plate material is imagewise exposed, heated and developed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photosensitive lithographic printing plate material and an image forming method using the photosensitive lithographic printing plate material.

[0002]

2. Description of the Related Art Conventionally, there is known a photosensitive lithographic printing plate material in which a photopolymerizable photosensitive layer and a protective layer are laminated on a support which has been subjected to a hydrophilic surface treatment. In addition, particularly in recent years, in order to quickly obtain a high-resolution lithographic printing plate material, and for the purpose of filmless, digital exposure based on image information using a laser is performed, and this is developed to obtain a lithographic printing plate. The manufacturing method is generalized.

As an example, for example, an output signal from an electronic plate making system or an image processing system or an image signal transmitted through a communication line modulates a light source to directly scan and expose a photosensitive material for printing. Systems for forming plates are known.

The photopolymerizable photosensitive layer is generally sensitized in order to adjust the wavelength to an acrylic monomer, an alkali-soluble resin and a photopolymerizable initiator and, if necessary (particularly when performing laser writing), a wavelength. It is known to contain pigments.

It is also known to provide a protective layer for the purpose of preventing polymerization inhibition by oxygen.

Exposure of a photopolymerizable photosensitive lithographic printing plate material
As a light source for plate making, a long-wavelength visible light source such as an Ar laser (488 nm) or an FD-YAG laser (532 nm) is used. More recently, for example, I
A semiconductor laser that uses nGaN-based or ZnSe-based materials and is capable of continuous oscillation in the 350 nm to 450 nm region is in the practical stage. The scanning exposure system using these short-wave light sources has an advantage that an economical system can be constructed while having a sufficient output because the semiconductor laser can be manufactured inexpensively due to its structure. Furthermore, conventional FD-
Compared to systems that use YAG or Ar lasers,
There is a possibility that it can be used for a photosensitive lithographic printing plate material having a short-wavelength photosensitive region that can be operated under a brighter safe light.

In the case of a photopolymerizable photosensitive lithographic printing plate material, it is usually subjected to image exposure and, if necessary, heat treatment, followed by washing with water for removing the protective layer, developing treatment for dissolving and removing unexposed portions, and washing with water. Treatment and finisher gum treatment for making the non-image area hydrophilic are performed to obtain a lithographic printing plate. At this time, it is known that a heat treatment is carried out after the image exposure to accelerate the polymerization reaction to obtain high sensitivity and high printing durability.

On the other hand, as a developer for the photosensitive lithographic printing plate material, in order to completely remove the photosensitive layer in the non-image area, that is, to perform development, it is usually used as an aqueous alkaline developer at pH 1
It was generally used at 2.5 or higher. However, in recent years, treatment with an alkaline developer having a lower pH has been desired from the viewpoint of workability, safety, environmental suitability and the like.

[0009]

However, in this method, since the reaction between light and heat is used twice, the influence of light scattering during exposure is apt to appear, and there is a problem in stable halftone dot reproducibility. There is. In particular, there is a problem in halftone dot uniformity within the plane due to the time difference between the end of image exposure by laser scanning and the heating.

Further, the photopolymerizable photosensitive lithographic printing plate material has a problem that it is difficult to secure sensitivity and long-term storage stability. This is because a long-term storage causes a dark reaction.

Further, when developing with a developing solution having a low pH, problems such as an increase in developability and the amount of developing sludge become apparent, and, on the other hand, the developing with a developing solution having a low pH results in formation of a photosensitive polymer layer. There is a problem in that, when trying to improve the developability, sensitivity, halftone dot reproducibility and storage stability are deteriorated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a photosensitive lithographic printing plate material having excellent storage stability, excellent sensitivity and halftone dot reproducibility and high image performance, and image formation. Is to provide a method.

[0013]

The above object of the present invention has been achieved by the following constitution.

(1) A photosensitive material having at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder on a support. Photolithographic printing plate material, which is imagewise exposed to light to cure the photosensitive layer imagewise, and then the non-image part of the photopolymerizable photosensitive layer is removed from the support with a developer to form a photocured image. In the photosensitive lithographic printing plate material described above, the polymer binder has a weight average molecular weight (Mw) of 15,000 to 30.
000, and has a monomer unit (A) having a carboxyl group and a unit (B) obtained by reacting an epoxy group-containing unsaturated compound with at least a part of the monomer unit having a carboxyl group as constituent elements, and A photosensitive lithographic printing plate material, which is a copolymer containing 10 to 30 mol% of (B), and which is subjected to a heat treatment and a development treatment after imagewise exposure.

(2) A photosensitive material having at least one photopolymerizable photosensitive layer on a support, which contains an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder. Photolithographic printing plate material, which is imagewise exposed to light to cure the photosensitive layer imagewise, and then the non-image part of the photopolymerizable photosensitive layer is removed from the support with a developer to form a photocured image. In the photosensitive lithographic printing plate material, the polymer binder has an acid value of 60 to 110 mgKOH / g,
A monomer unit (A) having a carboxyl group and a unit (B) obtained by reacting at least a part of the monomer unit having a carboxyl group with an epoxy group-containing unsaturated compound, as constituent elements, and A photosensitive lithographic printing plate material which is a copolymer containing 10 to 30 mol% and is characterized in that after imagewise exposure, it is subjected to heat treatment and then development.

(3) A photosensitive material having at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder on a support. Photolithographic printing plate material, which is imagewise exposed to light to cure the photosensitive layer imagewise, and then the non-image part of the photopolymerizable photosensitive layer is removed from the support with a developer to form a photocured image. In the photosensitive lithographic printing plate material described above, the polymer binder has a weight average molecular weight (Mw) of 15,000 to 30.
000, an acid value of 60 to 110 mgKOH / g, and a unit (B) obtained by reacting a monomer unit (A) having a carboxyl group and at least a part of the monomer unit having the carboxyl group with an epoxy group-containing unsaturated compound. ) As a component, and (B) 10
A photosensitive lithographic printing plate material, characterized in that the copolymer is contained in an amount of ˜30 mol%, and the imagewise exposure is followed by heat treatment and then development.

(4) The developer contains a silicate,
H10.0 to 12.5 (1) to
The photosensitive lithographic printing plate material as described in any one of (3).

(5) The heat treatment is performed at a plate surface temperature of 100.
~ 130 ° C for 5 to 60 seconds, characterized by (1) ~
The photosensitive lithographic printing plate material as described in any one of (4).

(6) The heat treatment is carried out 30 times after image exposure.
The photosensitive lithographic printing plate material as described in (5), which is performed within 0 seconds.

(7) The photosensitive lithographic printing plate material as described in any one of (1) to (6), which has an oxygen barrier layer on the photopolymerizable photosensitive layer.

(8) The photosensitive material according to any one of (1) to (7), wherein the support is an aluminum support which has been at least roughened and anodized. Lithographic printing plate material.

(9) The photosensitive lithographic printing plate material as described in (8), wherein the support is an aluminum support which is further subjected to a hydrophilic treatment or an undercoat treatment.

(10) A photosensitive material having at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder on a support. Image-wise exposing the photosensitive lithographic printing plate material imagewise to photo-cur the photosensitive layer, and then a non-image portion of the photo-polymerizable photosensitive layer is removed from the support with a developer to form a photo-cured image. In the image forming method, the polymer binder is
A weight average molecular weight (Mw) is 15,000 to 30,000, and a monomer unit (A) having a carboxyl group and a unit (B) obtained by reacting at least a part of the monomer unit having a carboxyl group with an epoxy group-containing unsaturated compound are prepared. It has as a component and the above (B) is 10
The image forming method is characterized in that the copolymer is contained in an amount of ˜30 mol%, and the imagewise exposure is followed by heat treatment and then development.

(11) A photosensitive material having at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder on a support. Image-wise exposing the photosensitive lithographic printing plate material imagewise to photo-cur the photosensitive layer, and then a non-image portion of the photo-polymerizable photosensitive layer is removed from the support with a developer to form a photo-cured image. In the image forming method, the polymer binder is
The acid value is 60 to 110 mgKOH / g, and the monomer unit (A) having a carboxyl group and the unit (B) obtained by reacting at least a part of the monomer unit having a carboxyl group with an epoxy group-containing unsaturated compound are constituent elements. Which is a copolymer containing (B) in an amount of 10 to 30 mol% and which is subjected to a heat treatment and a development treatment after the image exposure.

(12) A photosensitive material having at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder on a support. Image-wise exposing the photosensitive lithographic printing plate material imagewise to photo-cur the photosensitive layer, and then a non-image portion of the photo-polymerizable photosensitive layer is removed from the support with a developer to form a photo-cured image. In the image forming method, the polymer binder is
The weight average molecular weight (Mw) is 15,000 to 30,000, the acid value is 60 to 110 mgKOH / g, and at least a part of the monomer unit (A) having a carboxyl group and the monomer unit having the carboxyl group does not contain an epoxy group. A copolymer having a unit (B) obtained by reacting a saturated compound as a constituent and also containing 10 to 30 mol% of the above (B), which is subjected to heat treatment after image exposure and development treatment. An image forming method characterized by performing.

(13) The developer contains a silicate,
It is characterized in that the pH is 10.0 to 12.5 (1
The image forming method according to any one of 0) to (12).

(14) In the heat treatment, the plate surface temperature is 10
Characterized by performing the treatment at 0 to 130 ° C. for 5 to 60 seconds (1
The image forming method according to any one of 0) to (13).

(15) The heat treatment is performed 3 times after image exposure.
The image forming method as described in (14), which is performed within 00 seconds.

(16) An oxygen barrier layer is provided on the photopolymerizable photosensitive layer (10) to (15).
The image forming method according to any one of 1.

(17) Any one of (10) to (16), wherein the support is an aluminum support that has been at least roughened and anodized.
The image forming method according to item.

(18) The image forming method as described in (17), wherein the support is an aluminum support which has been further subjected to a hydrophilic treatment or a subbing treatment.

The present invention will be described in detail below. The support that can be used in the photosensitive lithographic printing plate material of the present invention and the photosensitive lithographic printing plate material used in the image forming method of the present invention is, for example, a metal plate of aluminum, stainless steel, chromium, nickel or the like, or a polyester film. , A polyethylene film, a plastic film such as a polypropylene film laminated or vapor-deposited with the above-mentioned metal thin film, or a polyester film, a vinyl chloride film, a nylon film or the like whose surface is subjected to a hydrophilic treatment can be used. An aluminum plate is preferably used, and in this case, a pure aluminum plate or an aluminum alloy plate may be used.

As the aluminum alloy for the support, various materials can be used. For example, alloys of aluminum with metals such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, titanium, sodium and iron. Is used.

The photosensitive lithographic printing plate material of the present invention and the support which can be used in the image forming method of the present invention are degreased in order to remove rolling oil on the surface before roughening (graining treatment). It is preferable to apply a treatment. As the degreasing treatment, a degreasing treatment using a solvent such as trichlene and thinner, an emulsion degreasing treatment using an emulsion such as kesilon, triethanol and the like are used. An aqueous solution of alkali 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, it is possible to remove stains and oxide films which cannot be removed only by the above degreasing treatment. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, smut is formed on the surface of the support. In this case, dip it in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid, or a mixed acid thereof to desmut it. It is preferable to apply a treatment.

Examples of the surface roughening method include a mechanical method and an electrolytic etching method.

The mechanical surface roughening method used is not particularly limited, but a brush polishing method and a honing polishing method are preferable. The roughening by the brush polishing method is performed by, for example, rotating a rotating brush using brush bristles having a diameter of 0.2 to 0.8 mm, and, for example, a particle diameter of 10 to 100 μm on the support surface.
It can be carried out by pressing a brush while supplying a slurry in which the particles of the volcanic ash are uniformly dispersed in water. Roughening by honing polishing is performed, for example, with a particle size of 10 to 100.
Particles of μm volcanic ash can be evenly dispersed in water, pressure is applied from a nozzle to eject, and the surface of the support can be obliquely collided for roughening. Also, for example, on the surface of the support,
Abrasive particles having a particle size of 10 to 100 μm are
2.5 × 10 ³ to 10 × 10 ³ pieces / cm ² at intervals of μm
Laminate the coated sheets so that they exist at the density of
Roughening can also be performed by applying pressure to transfer the rough surface pattern of the sheet.

After the surface is roughened by the above-mentioned mechanical surface roughening method, it is preferable to immerse it in an aqueous solution of acid or alkali in order to remove the abrasive, the aluminum scraps and the like formed on the surface of the support. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid and the like, and examples of the base include sodium hydroxide, potassium hydroxide and the like. Among these, it is preferable to use an alkaline aqueous solution such as sodium hydroxide. The amount of aluminum dissolved on the surface is preferably 0.5 to 5 g / m ² . After soaking in an alkaline solution, phosphoric acid, nitric acid, sulfuric acid,
It is preferable to perform a neutralization treatment by immersing in an acid such as chromic acid or a mixed acid thereof.

The electrochemical surface-roughening method is not particularly limited, but a method of electrochemically surface-roughening in an acidic electrolyte is preferable. As the acidic electrolytic solution, an acidic electrolytic solution which is usually used in an electrochemical roughening method can be used,
It is preferable to use a hydrochloric acid-based or nitric acid-based electrolyte. For the electrochemical roughening method, for example, Japanese Patent Publication No. 48-2
The methods described in Japanese Patent No. 8123, British Patent No. 896,563, and Japanese Patent Laid-Open No. 53-67507 can be used. This roughening method is generally 1-5.
It can be carried out by applying a voltage in the range of 0 V, but it is preferable to select it in the range of 10 to 30 V. 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. Electricity is 100-5000c /
A range of dm ² can be used, but from 100 to 200
It is preferable to select from the range of 0 c / dm ² . The temperature for carrying out this surface roughening method may be in the range of 10 to 50 ° C, but is preferably selected from the range of 15 to 45 ° C.

Electrification using nitric acid-based electrolyte as the electrolyte
When performing a surface roughening, a range of 1 to 50 volts is generally used.
Can be done by applying a voltage of
It is preferable to select from the range of 10 to 30 volts. Current density
10 to 200 A / dm ²The range of
Can, but 20-100A / dm²It is preferable to choose from the range
Good Electricity is 100-5000c / dm²Range of
Can be used, but 100 to 2000 c / dm²
It is preferable to select from the range. Performs an electrochemical roughening method
The heating temperature may be in the range of 10 to 50 ° C.
Is preferably selected from the range of 15 to 45 ° C. Electrolyte
The nitric acid concentration in is preferably 0.1 to 5 mass%. electrolytic
The solution should contain nitrates, chlorides, amines, and
Luthedes, phosphoric acid, chromic acid, boric acid, acetic acid, oxalic acid
Etc. can be added.

When a hydrochloric acid-based electrolyte is used as the electrolyte,
Generally, it can be performed by applying a voltage in the range of 1 to 50 V, but it is preferable to select from the range of 2 to 30 V. Current density is 10 to 200 A / d
A range of m ² can be used, but 50 to 150 A /
It is preferable to select from the range of dm ² . The amount of electricity is 100
A range of up to 5000 c / dm ² can be used,
100 to 2000 c / dm ² , further 200 to 1000
It is preferable to select from the range of c / dm ² . The temperature for carrying out the electrochemical graining method may be in the range of 10 to 50 ° C, but is preferably selected in 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 above-mentioned electrochemical surface roughening method, it is preferable to immerse it in an aqueous solution of acid or alkali in order to remove aluminum dust and the like on the surface. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid and the like, and examples of the base include sodium hydroxide, potassium hydroxide and the like. Among these, it is preferable to use an aqueous solution of alkali. The amount of aluminum dissolved on the surface is preferably 0.5 to 5 g / m ² . Further, it is preferable that after the dipping treatment with an aqueous alkali solution, the dipping treatment is carried out by dipping in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid or a mixed acid thereof.

The mechanical surface-roughening treatment method and the electrochemical surface-roughening method may be used independently for surface-roughening, or the mechanical surface-roughening method may be followed by the electrochemical surface-roughening method. You may carry out and roughen.

After the surface roughening treatment, anodizing treatment can be performed. The method of anodizing treatment that can be used in the present invention is not particularly limited, and a known method can be used. By performing the anodizing treatment, an oxide film is formed on the support. The anodizing treatment includes
A method in which an aqueous solution containing sulfuric acid and / or phosphoric acid or the like at a concentration of 10 to 50% is used as an electrolytic solution and electrolysis is performed at a current density of 1 to 10 A / dm ² is preferably used, but in addition, US Pat. No. 1,412,768 is used. The method of electrolyzing in sulfuric acid at a high current density described in Japanese Patent No. 3,511,661, the method of electrolysis using phosphoric acid described in Japanese Patent No. 3,511,661, chromic acid, oxalic acid, malonic acid, etc. Examples include a method of using a solution containing one kind or two or more kinds. The formed anodic oxide coating amount is appropriately 1 to 50 mg / dm ² , and preferably 10 to 40 mg / dm ² . The anodic oxide coating amount is, for example, an aluminum plate with a phosphoric acid chromic acid solution (phosphoric acid 85%
Liquid: 35 ml, chromium oxide (IV): 20 g is dissolved in 1 L of water) to dissolve the oxide film, and the mass change of the plate before and after dissolution is measured.

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

Further, after these treatments are carried out, water-soluble resins such as polyvinylphosphonic acid, polymers and copolymers having a sulfonic acid group in the side chain, polyacrylic acid, water-soluble metal salts (eg boric acid). Zinc), a yellow dye, an amine salt or the like as an undercoat is also suitable. Further, a sol-gel treated substrate having a functional group capable of causing an addition reaction by a radical covalently bonded as disclosed in JP-A-5-304358 is also suitably used.

As the support, various materials can be used as described above, and, for example, a polyester film, a vinyl chloride film, a nylon film or the like whose surface has been hydrophilized can also be used. As a hydrophilic treatment method for the film, sulfuric acid treatment, oxygen plasma etching treatment, corona discharge treatment, provision of a water-soluble resin layer coating layer and the like are preferably used. In the practice of the present invention, the surface is roughened, anodized, sealed,
And an aluminum plate subjected to a subbing treatment is particularly preferable.

Addition polymerization that can be used in the photosensitive lithographic printing plate material of the present invention and the photopolymerizable photosensitive layer (hereinafter sometimes referred to as photosensitive layer) of the photosensitive lithographic printing plate material used in the image forming method of the present invention. Possible ethylenically unsaturated double bond-containing monomers (hereinafter sometimes referred to as monomers) include known monomers having radically polymerizable ethylenically unsaturated bonds.

Specific compounds include, for example, 2-ethylhexyl acrylate, 2-hydroxypropyl acrylate, glycerol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate, tetrahydrofurfuryloxyethyl acrylate, tetrahydrofurfuryl. Oxyhexanolide acrylate, 1,3-
Acrylate of ε-caprolactone adduct of dioxane alcohol, monofunctional acrylic acid esters such as 1,3-dioxolane acrylate, or methacrylic acid, itaconic acid, crotonic acid, in which these acrylates are replaced by methacrylate, itaconate, crotonate, maleate, 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, hydroxypivalin. Acid neopentyl glycol diacrylate, neopentyl glycol adipate diacrylate, Diacrylate ε- caprolactone adduct of Dorokishipibarin neopentyl glycol, 2- (2-hydroxy-1,1-dimethylethyl)
-5-Hydroxymethyl-5-ethyl-1,3-dioxane diacrylate, tricyclodecane dimethylol acrylate, ε-caprolactone adduct of tricyclodecane dimethylol acrylate, diglycidyl ether of 1,6-hexanediol Bifunctional acrylic acid esters such as acrylates, or methacrylic acid obtained by replacing these acrylates with methacrylate, itaconate, crotonate, maleate, itaconic acid, crotonic acid, maleic acid ester such as trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate , Trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate , Dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ε-caprolactone adduct of dipentaerythritol hexaacrylate, pyrogallol triacrylate, propionic acid / dipentaerythritol triacrylate, propionic acid / dipentaerythritol tetraacrylate, hydroxypivalyl Aldehyde-modified dimethylolpropane triacrylate and other polyfunctional acrylic acid ester acids, and their EO-modified products, or these acrylates as methacrylates, itaconates,
Examples thereof include methacrylic acid, itaconic acid, crotonic acid, and maleic acid ester, which are substituted for crotonate and maleate.

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

Examples of the prepolymer 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, Polybasic acids such as pimelic acid, sebacic acid, dodecanoic acid and tetrahydrophthalic acid, and ethylene glycol, propylene glycol, diethylene glycol, propylene oxide, 1,4-butanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin (Meth) acrylic acid was introduced into a polyester obtained by binding a polyhydric alcohol such as trimethylolpropane, pentaerythritol, sorbitol, 1,6-hexanediol, and 1,2,6-hexanetriol. Li ester acrylates, such as bisphenol A · epichlorhydrin · (meth)
Epoxy acrylates such as acrylic acid, phenol novolac, epichlorohydrin, and (meth) acrylic acid in which (meth) acrylic acid is introduced into an epoxy resin, such as ethylene glycol, adipic acid, tolylene diisocyanate, 2-hydroxyethyl acrylate, and polyethylene. Glycol Tolylene Diisocyanate / 2
-Hydroxyethyl acrylate, hydroxyethyl phthalyl methacrylate / xylene diisocyanate,
Urethane acrylate obtained by introducing (meth) acrylic acid into urethane resin, such as 1,2-polybutadiene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate and trimethylolpropane / propylene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate. For example, polysiloxane acrylate, silicone resin acrylates such as polysiloxane diisocyanate and 2-hydroxyethyl acrylate, and other alkyd-modified acrylates obtained by introducing a (meth) acryloyl group into an oil-modified alkyd resin,
Examples include prepolymers such as spirane resin acrylates.

The photosensitive lithographic printing plate material of the present invention and the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate material used in the image forming method of the present invention have a phosphazene monomer, triethylene glycol and isocyanuric acid EO (ethylene oxide).
Monomers such as modified diacrylate, isocyanuric acid EO modified triacrylate, dimethylol tricyclodecane diacrylate, trimethylol propane acrylic acid benzoate, alkylene glycol type acrylic acid modified, urethane modified acrylate and the like It may contain addition-polymerizable oligomers and prepolymers having the constituent units formed.

Furthermore, the photosensitive lithographic printing plate material of the present invention and the photosensitive lithographic printing plate material used in the image forming method of the present invention contain at least one (meth) acryloyl group as an ethylenic monomer. Examples thereof include phosphoric acid ester compounds. The compound is a compound in which at least a part of the hydroxyl groups of phosphoric acid is esterified, and
There is no particular limitation as long as it has a (meth) acryloyl group.

In addition to these, Japanese Patent Laid-Open Nos. 58-212994, 61-6649, 62-46688, 62-48589 and 62-173295.
No. 62-187092 and No. 63-671.
89, Japanese Patent Application Laid-Open No. 1-244891, and the like, and the like. Further, "11290 chemical products", Chemical Industry Daily, p. 286-p. 294, the compound described in "UV / EB curing handbook (raw material)", Polymer Publishing Association, p. The compounds described in 11 to 65 and the like can also be preferably used in the present invention. Among these, compounds having two or more acryl groups or methacryl groups in the molecule are preferable in the present invention, and those having a molecular weight of 10,000 or less, more preferably 5,000 or less are preferable.

In the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate material of the present invention and the photosensitive lithographic printing plate material of the present invention, the above-mentioned monomer is contained in the photosensitive composition of the photosensitive layer. In, in the range of 1.0 to 80.0 mass% is preferable, and more preferably 3.0 to 70.0 mass%.
Is the range.

The polymer binder that can be used in the photosensitive lithographic printing plate material of the present invention and the photosensitive lithographic printing plate material used in the image forming method of the present invention is a copolymer having a monomer unit having a carboxyl group. , For example, allyl glycidyl ether, glycidyl (meth) acrylate, α
Aliphatic epoxies such as ethyl glycidyl (meth) acrylate, glycidyl crotonate, glycidyl isocrotonate, crotonyl glycidyl ether, itaconic acid monoalkyl monoglycidyl ester, fumaric acid monoalkyl monoglycidyl ester, maleic acid monoalkyl monoglycidyl ester A group-containing unsaturated compound, or an alicyclic epoxy group-containing unsaturated compound such as 3,4-epoxycyclohexylmethyl (meth) acrylate,
It is a reaction product obtained by reacting with the carboxyl group, and is a copolymer containing 10 to 30 mol% of units in which the carboxyl group and the epoxy group-containing unsaturated compound have reacted.

In at least one of the present inventions, the weight average molecular weight (Mw) of the polymer binder is 15,000 to 30,000, but also in the present invention, the weight average molecular weight of the polymer binder is 15,000 to 30,000. It is preferable. This makes it possible to obtain a photosensitive lithographic printing plate material having good storage stability, excellent sensitivity and halftone dot reproducibility and high image performance.

At least one of the present inventions has an acid value of the polymer binder of 60 to 110 mgKOH / g.
In another invention, the acid value of the polymer binder is 60 to 110 mg.
It is preferably KOH / g. This makes it possible to obtain a photosensitive lithographic printing plate material having good storage stability, excellent sensitivity and halftone dot reproducibility and high image performance.

In the present invention, the weight average molecular weight is a value measured by gel permeation chromatography (GPC).

In the present invention, the acid value is the number of mg of potassium hydroxide necessary to neutralize 1 g of the polymer binder. The acid value can be measured as follows.
The sample is diluted 50 times with methyl cellosolve and titrated with 0.1 N potassium hydroxide. The inflection point of the pH curve obtained using a pH meter is the neutralization point. The acid value is calculated from the amount of potassium hydroxide required to reach this neutralization point.

The copolymer having a monomer unit having a carboxyl group and the epoxy group-containing unsaturated compound can be reacted at a temperature of about 80 to 120 ° C. and a time of about 1 to 50 hours. As a method for synthesizing the reaction product, a generally known polymerization method can be used. For example, “polymer synthesis experimental method” by Tokyo Kagaku Dojin, W. R. Sorenson, T .; W. Camp
It can be synthesized according to the methods described in literatures such as Bell's co-authorship and patents such as JP-A-10-315598 and JP-A-11-271963, and the like.

Further, as a copolymer having a monomer unit having the above-mentioned carbonyl group, α, as described in (5) below,
A vinyl-based copolymer having a β-unsaturated carboxylic acid monomer unit as a constituent is preferable, and a vinyl-based copolymer containing at least one of the monomers described in (1) to (17) below is contained. Is also preferable.

(1) A monomer having an aromatic hydroxyl group, for example, o- (or p-, m-) hydroxystyrene, o-
(Or p-, m-) hydroxyphenyl acrylate and the like.

(2) Monomers having aliphatic hydroxyl groups, 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, for example, 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 and N- (p-toluenesulfonyl) methacrylamide.

(5) α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, β-methacryloyloxyethyl hydrogen phthalate, β-methacryloyloxyethyl Hydrogen succinate, etc.

(6) Substituted or unsubstituted alkyl acrylate, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate. , Decyl acrylate,
Undecyl acrylate, dodecyl acrylate, benzyl acrylate, cyclohexyl acrylate, acrylic acid-
2-chloroethyl, N, N-dimethylaminoethyl acrylate, glycidyl acrylate and the like.

(7) Substituted or unsubstituted alkyl methacrylate, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate. , Decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, 2-chloroethyl methacrylate, N, N-dimethylaminoethyl methacrylate, glycidyl methacrylate and the like.

(8) Acrylamide or methacrylamide, such as acrylamide, methacrylamide, N-
Ethyl acrylamide, N-hexyl acrylamide,
N-cyclohexylacrylamide, N-phenylacrylamide, N- (4-nitrophenyl) acrylamide, N-ethyl-N-phenylacrylamide, N-
(4-hydroxyphenyl) acrylamide, N- (4
-Hydroxyphenyl) methacrylamide and the like.

(9) Monomers containing a fluorinated alkyl group 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.

(10) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether,
Propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, etc.

(11) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.

(12) Styrenes such as styrene, methylstyrene, chloromethylstyrene and the like.

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

(14) Olefins such as ethylene,
Propylene, i-butylene, butadiene, isoprene and the like.

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

(16) Monomers having a cyano group, for example, acrylonitrile, methacrylonitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile, 2-cyanoethyl acrylate, o- (or m-, p-) cyanostyrene. etc.

(17) 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-dimethyl acrylamide, acryloyl morpholine, N-i-propyl acrylamide, N, N- Diethyl acrylamide etc.

If necessary, the above-mentioned polymer binder may be used in combination with any other polymer binder such as polyvinyl butyral resin, polyurethane resin, polyamide resin, polyester resin, epoxy resin, novolac resin and natural resin. Good.

The above copolymer preferably accounts for 50 to 100% by mass in the polymer binder.
It is more preferably 0% by mass.

The content of the polymer binder in the photosensitive composition for coating and forming the photosensitive layer is preferably in the range of 10 to 90% by mass, more preferably 15 to 70% by mass, and further preferably 20 to 50% by mass. From the viewpoint of sensitivity, it is particularly preferable to use in the range of%.

Photopolymerization initiators which can be preferably used in the photosensitive lithographic printing plate material of the present invention and the photosensitive lithographic printing plate material used in the image forming method of the present invention are preferably those described in J. Carbonyl compounds, organosulfur compounds, persulfides, as described in Chapter 5 of "Light Sensitive Systems" by J. Kosar.
Examples thereof include redox compounds, azo compounds, diazo compounds, halogen compounds, photoreducible dyes, and the like, and the compounds disclosed in British Patent 1,459,563 are also preferable.

Specifically, the following examples can be given, but the invention is not limited thereto. That is, benzoin methyl ether, benzoin-i-propyl ether, α, α
Benzoin derivatives such as -dimethoxy-α-phenylacetophenone; benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-
Benzophenone derivatives such as bis (dimethylamino) benzophenone; thioxanthone derivatives such as 2-chlorothioxanthone and 2-i-propylthioxanthone; anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone; N-methylacridone, N-butyl Acridone derivatives such as acridone; α, α-diethoxyacetophenone, benzyl, fluorenone, xanthone and uranyl compounds, as well as JP-B-59-1281, JP-A-61-9621 and JP-A-60-60.
The triazine derivative described in JP-A-104-104; JP-A-59-
1504 and 61-243807; organic peroxides; JP-B-43-23684 and 44;
No. 6413, No. 44-6413, No. 47-
1604 and U.S. Pat. No. 3,567,453.
Diazonium compounds described in U.S. Pat.
No. 8,328, No. 2,852,379 and No. 2,
Organic azide compounds described in 940,853; Japanese Patent Publication Sho 3
6-22062, 37-13109, 38-18015 and 45-9610, o-quinone diazides; JP-B-55-391.
62, JP-A-59-14023, and "Macromolecules".
s) ”, various onium compounds described in Vol. 10, p. 1307 (1977); azo compounds described in JP-A-59-142205; JP-A-1-54440, European Patents 109, 851 and 126. , 712 and "Journal of Imaging Science (J.Imag.Sci.)", Vol. 30, p. 174 (19).
1986). Metal allene complexes described in JP-A-5-21386.
No. 1 and No. 5-255347 (oxo) sulfonium organic boron complex; titanocenes described in JP-A-59-152396 and JP-A-61-151197; "Coordination Chemistry Review (Coordination Chemistry Review). R
84), pages 85-277 (1988).
And transition metal complexes containing a transition metal such as ruthenium described in JP-A-2-182701;
2,4,5-Triarylimidazole dimers described in JP-A-209477; carbon tetrabromide, JP-A-59-107.
Organic halogen compounds described in Japanese Patent No. 344, etc.

Among them, titanocenes are preferable. Specific examples of titanocenes include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4. , 5,6-Pentafluorophen-1-yl, di-cyclopentadienyl-Ti
-Bis-2,3,5,6-tetrafluorophenyl-1-
Il, di-cyclopentadienyl-Ti-bis-2,
4,6-Trifluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-
2,4-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-
Pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2, 4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrid-1-yl) phenyl) titanium (IRUGACURE784: manufactured by Ciba Specialty Chemicals) and the like can be mentioned. However, the present invention is not limited to this.

When laser light is used as the light source, it is preferable to add a sensitizing dye to the photosensitive layer.

Examples of the compound for wavelength sensitizing from visible light to near infrared include cyanine, phthalocyanine, merocyanine, porphyrin, spiro compound, ferrocene, fluorene, flugide, imidazole, perylene, phenazine, phenothiazine, polyene, azo compound, diphenylmethane. , Triphenylmethane, polymethine acridine, coumarin, ketocoumarin, quinacridone, indigo, styryl, pyrylium compounds, pyrromethene compounds,
Examples thereof include pyrazolotriazole compounds, benzothiazole compounds, barbituric acid derivatives, and thiobarbituric acid derivatives, and further, European Patent 568,993, US Patents 4,508,811, 5,227,227, and Japanese Unexamined Patent Publication No. 2001-125255, JP-A-11-271
The compounds described in Japanese Patent No. 969 etc. are also used.

In the present invention, a preferable specific example of the combination of the above-mentioned photopolymerization initiator and sensitizing dye is described in JP-A-200
The combination described in JP-A No. 1-125255 and JP-A No. 11-271969 can be mentioned.

The blending amount of these photopolymerization initiators is not particularly limited, but preferably 0.1 to 20 with respect to 100 parts by mass of the addition-polymerizable ethylenically unsaturated double bond-containing monomer according to the present invention. Parts by mass. The molar ratio of the photopolymerization initiator to the sensitizing dye is preferably 1: 100 to 100: 1.

In the photosensitive lithographic printing plate material of the present invention and the coating composition of the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate material used in the image forming method of the present invention, in addition to the components described above, a photosensitive lithographic printing plate is used. It is desirable to add a polymerization inhibitor in order to prevent unnecessary polymerization of the polymerizable ethylenically unsaturated double bond monomer during the production or storage of the printing plate material. Suitable polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol,
Pyrogallol, t-butylcatechol, benzoquinone,
4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl-6-)
t-butylphenol), N-nitrosophenylhydroxylamine primary cerium salt, 2-t-butyl-6-
(3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,2,6
Examples thereof include hindered amines such as 6, -tetramethylpiperidine derivatives.

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

A coloring agent can also be used, and as the coloring agent, conventionally known ones including commercially available ones can be preferably used. For example, those described in the revised new edition "Pigment Handbook", edited by Japan Pigment Technology Association (Seibundo Shinkosha), Color Index Handbook, etc. may be mentioned.

The types of pigments include black pigments, yellow pigments, red pigments, brown pigments, purple pigments, blue pigments, green pigments, fluorescent pigments and metal powder pigments. Specifically, inorganic pigments (titanium dioxide, carbon black, graphite, zinc oxide, Prussian blue, cadmium sulfide, iron oxide, and chromates of lead, zinc, barium and calcium) and organic pigments (azo, thioindigo). Pigments, anthraquinone pigments, anthanthrone pigments, triphendioxazine pigments, vat dye pigments, phthalocyanine pigments and their derivatives, quinacridone pigments, etc.).

Among these, it is preferable to select and use a pigment having substantially no absorption in the absorption wavelength range of the spectral sensitizing dye corresponding to the exposure laser used, and in this case, the pigment at the laser wavelength used is selected. The reflection absorption of the pigment using the integrating sphere is preferably 0.05 or less. The amount of the pigment added is 0.1 to the solid content of the composition.
It is preferably 10% by mass, more preferably 0.2 to 5% by mass.

As an exposure light source, an argon laser (48
(8 nm) or SHG-YAG laser (532 nm), it is preferable to use a violet pigment or a blue pigment from the viewpoints of pigment absorption in the above-mentioned photosensitive wavelength region and visibility after development. Examples of such materials include cobalt blue, cerulean blue, alkali blue lake, phonatone blue 6G, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue farst sky blue, indanthrene blue, indico, dioxane violet, iso Examples thereof include biolanthrone violet, indanthrone blue, and indanthrone BC. Among these, phthalocyanine blue and dioxane violet are more preferable.

Further, a plasticizer may be contained in order to improve the adhesiveness to the support. Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, didodecyl phthalate, diisodecyl phthalate, butylbenzyl phthalate, diisononyl phthalate, ethyl phthalyl ethyl. Examples thereof include glycol, dimethyl isophthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, and triacetyl glycerin. The addition amount of the plasticizer is preferably about 0 to 3% by mass, more preferably 0.1 to 2% by mass, based on the solid content of the composition.

Further, the above composition may contain a surfactant as a coatability improving agent within a range not impairing the performance of the present invention. Among them, the fluorine-based surfactant is preferable.

In order to improve the physical properties of the cured film,
Additives such as inorganic fillers and plasticizers such as dioctyl phthalate, dimethyl phthalate and tricresyl phosphate may be added. The addition amount of these is preferably 10% or less of the total solid content.

The solvent used when preparing the photosensitive lithographic printing plate material of the present invention and the photosensitive composition of the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate material used in the image forming method of the present invention is, for example, , Alcohol: polyhydric alcohol derivatives, sec-butanol, isobutanol, n-hexanol, benzyl alcohol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,5-pentanediol, and ethers: propylene glycol monobutyl ether. , Dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, ketones, aldehydes: diacetone alcohol, cyclohexanone, methylcyclohexanone, and esters: ethyl lactate, butyl lactate, diethyl oxalate, Ikikosan methyl and the like preferably.

Prepared Photosensitive Composition (Photosensitive Layer Coating Solution)
Can be coated on a support by a conventionally known method and dried to prepare a photosensitive lithographic printing plate material. As a coating method of the coating liquid, for example, air doctor coater method, blade coater method, wire bar method, knife coater method, dip coater method, reverse roll coater method, gravure coater method,
Cast coating method, curtain coater method, extrusion coater method and the like can be mentioned.

When the drying temperature of the photosensitive layer is low, sufficient printing durability cannot be obtained, and when it is too high, not only Marangoni occurs but also fog in non-image area occurs.
As a preferable drying temperature range, a range of 60 to 160 ° C is preferable, a range of 80 to 140 ° C is more preferable, and a range of 90 to 120 ° C is particularly preferable.

A protective layer is preferably provided on the upper side of the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate material of the present invention and the photosensitive lithographic printing plate material used in the image forming method of the present invention.
The protective layer (oxygen barrier layer) preferably has high solubility in a developer (generally an alkaline aqueous solution) described later.

Preferred examples of the material constituting the protective layer include polyvinyl alcohol, polysaccharides, polyvinylpyrrolidone, polyethylene glycol, gelatin,
Glue, casein, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, hydroxyethyl starch, gum arabic, sucrose octaacetate, ammonium alginate, sodium alginate,
Examples thereof include polyvinylamine, polyethylene oxide, polystyrene sulfonic acid, polyacrylic acid, water-soluble polyamide and the like. These compounds may be used alone or in combination of two or more to form a coating composition. A particularly preferable compound is polyvinyl alcohol.

To prepare a protective layer coating composition, the above materials can be dissolved in a suitable solvent to prepare a coating solution.
This coating solution is coated on the photopolymerizable photosensitive layer according to the present invention,
The protective layer can be formed by drying. The thickness of the protective layer is preferably 0.1 to 5.0 μm, particularly preferably 0.
It is 5 to 3.0 μm. The protective layer may further contain a surfactant, a matting agent, etc., if necessary.

As the coating method of the protective layer, the known methods mentioned in the above examples can be preferably used. The drying temperature of the protective layer is more preferably lower than the drying temperature of the photosensitive layer. The difference from the drying temperature of the photosensitive layer is preferably 10 ° C. or more, more preferably 20 ° C. or more, and the upper limit in that case is preferably about 50 ° C. at most.

The drying temperature of the protective layer is preferably lower than the glass transition temperature (Tg) of the binder contained in the photosensitive layer. The difference between the drying temperature of the protective layer and the glass transition temperature (Tg) of the binder contained in the photosensitive layer is preferably 20 ° C. or more, more preferably 40 ° C. or more, and the upper limit of the difference is at most about 60 ° C. Is preferred.

The light source for imagewise exposing the photosensitive lithographic printing plate material of the present invention and the photosensitive lithographic printing plate material used in the image forming method of the present invention is, for example, a laser, a light emitting diode, a xenon lamp, a xenon flash lamp or a halogen lamp. , Carbon arc lamps, metal halide lamps, tungsten lamps, high pressure mercury lamps, electrodeless light sources and the like.

In the case of collective exposure, a mask material having a negative pattern of a desired exposure image formed of a light-shielding material may be superposed on the photopolymerizable photosensitive layer and exposed.

When an array type light source such as a light emitting diode array is used, or when a light source such as a halogen lamp, a metal halide lamp or a tungsten lamp is exposed and controlled by an optical shutter material such as liquid crystal or PLZT, an image signal is used. It is possible and preferable to perform appropriate digital exposure. In this case, direct writing can be performed without using a mask material.

The laser exposure is suitable for direct writing without using a mask material, because light can be focused into a beam and scanning exposure can be performed according to image data.
Further, when a laser is used as a light source, it is easy to reduce the exposure area to a minute size, and high-resolution image formation becomes possible.

As the laser light source, any of an argon laser, a He-Ne gas laser, a YAG laser, a semiconductor laser and the like can be preferably used. Laser scanning methods include cylinder outer surface scanning, cylinder inner surface scanning, and plane scanning. In the cylindrical outer surface scanning, laser exposure is performed while rotating a drum having a recording material wound on the outer surface, and rotation of the drum is main scanning and movement of laser light is sub scanning. In the cylindrical inner surface scanning, the recording material is fixed to the inner surface of the drum, the laser beam is irradiated from the inner side, and the main scanning is performed in the circumferential direction by rotating a part or the whole of the optical system, and a part of the optical system or Sub-scanning is performed in the axial direction by linearly moving the whole body in parallel with the axis of the drum.
In plane scanning, a polygon mirror or galvanometer mirror and fθ
Main scanning of laser light is performed by combining a lens and the like, and sub-scanning is performed by moving the recording medium. The scanning of the outer surface of the cylinder and the scanning of the inner surface of the cylinder make it easier to increase the accuracy of the optical system and are suitable for high-density recording.

In the present invention, after the image exposure, a heat treatment is carried out in order to accelerate the image forming reaction and improve the sensitivity and printing durability.
The method of heat treatment is not particularly limited, but a non-contact method with respect to the image forming surface is preferable, and a commercially available automatic processor equipped with an ordinary thermostatic bath, a hot air dryer and a heat treatment section can be used. The heating temperature is preferably a plate surface temperature of 100 to 130 ° C. If the temperature is too high, there are problems such as fogging of non-image areas, and if the temperature is too low, there are problems such as insufficient sensitivity and printing durability. The heating time is preferably 5 to 60 seconds. If the heating time is too long, there is a problem such as fogging of the non-image area, and if the heating time is too short, there are problems such as insufficient sensitivity and printing durability. The time from the end of exposure to the heat treatment is preferably within 300 seconds. Thirty
If it exceeds 0 seconds, problems such as insufficient sensitivity and printing durability occur.

The image-exposed photopolymerizable photosensitive layer of the photosensitive lithographic printing plate material of the present invention and the photosensitive lithographic printing plate material used in the image forming method of the present invention is cured in the exposed area. By developing this with a developing solution, an unexposed portion is removed and an image can be formed. As such a developing solution, a conventionally known alkaline aqueous solution can be used. Sodium silicate, potassium, ammonium; sodium diphosphate, potassium, ammonium; sodium bicarbonate, potassium, ammonium; sodium carbonate, potassium, ammonium; sodium bicarbonate, potassium, ammonium; boric acid Sodium, potassium, ammonium; sodium hydroxide, potassium,
An alkaline developing solution using an inorganic alkaline agent such as ammonium and lithium can be used.

Further, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, mono-i-propylamine,
Di-i-propylamine, tri-i-propylamine,
Organic alkali agents such as butylamine, monoethanolamine, diethanolamine, triethanolamine, mono-i-propanolamine, di-i-propanolamine, ethyleneimine, ethylenediamine and pyridine can also be used.

These alkaline agents may be used alone or in combination of two or more. If necessary, an organic solvent such as an anionic surfactant, an amphoteric surfactant or alcohol can be added to the developer.

The developer used in the present invention contains a silicate and preferably has a pH of 10.0 to 12.5, more preferably pH 10.5 to 12.4. The effect of the present invention is specifically exhibited by such development. That is, not only can the developability and sensitivity that were conventionally insufficient be brought out as sufficient performance, but also the performance such as improvement of development sludge performance and improvement of printing durability can be improved at the same time.

[0116]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
In addition, "part" in an Example represents a "mass part" unless there is particular notice.

Example 1-1 Photosensitive planographic printing plate material 1
Preparation of 20 (Preparation of Polymer Binders A to T) In a three-necked flask under a nitrogen stream, 19.5 parts (0.195 mol) of methyl methacrylate (Compound 1) and methacrylic acid (Compound 2) 27.
0 parts (0.314 mol), 3.5 parts of ethyl methacrylate (compound 3) (0.031 mol), 100 parts of ethanol and 1.23 parts of α, α′-azobisisobutyronitrile were added, and nitrogen was added. A polymer was obtained by reacting in an oil bath at 80 ° C. for 6 hours in an air stream. Then, 1 part of triethylammonium chloride and glycidyl methacrylate (epoxy group-containing unsaturated compound: compound 4) 2 were added to the polymer.
3.1 parts (0.163 mol) were added, and the mixture was mixed at a temperature of 25 ° C for 3
The reaction was carried out for a time to obtain a polymer binder A (Compound 6). G
The weight average molecular weight measured using PC is about 28,000.
Met.

[0118]

[Chemical 1]

The monomer unit ratio shown in Table 1 and the ratio of the epoxy group-containing unsaturated compound reacted with the carboxyl group were changed by changing the charged amount, and the reaction time of the polymer was adjusted to change the weight average molecular weight. Polymer binder B was prepared in the same manner as in the preparation of polymer binder A, except that it was changed.
~ T was obtained.

[0120]

[Chemical 2]

[0121]

[Table 1]

(Production of Support) An aluminum plate (material 1050, temper H16) having a thickness of 0.24 mm was immersed in a 5% sodium hydroxide aqueous solution kept at 65 ° C., and degreasing treatment was performed for 1 minute. Then, it was washed with water. This degreased aluminum plate was immersed in a 10% hydrochloric acid aqueous solution kept at 25 ° C. for 1 minute for neutralization, and then washed with water. Next, this aluminum plate was electrolytically surface-roughened for 60 seconds by an alternating current in a 0.3% by mass aqueous hydrochloric acid solution at 25 ° C. and a current density of 100 A / dm ² , and then kept at 60 ° C. Desmutting treatment was performed for 10 seconds in a dripped 5% aqueous sodium hydroxide solution. The desmutted roughened aluminum plate is placed in a 15% sulfuric acid solution at 25 ° C. and a current density of 10 A / d.
Anodizing treatment was carried out for 1 minute under the condition of m ² and voltage of 15 V, and further, sealing treatment was carried out with 3% sodium silicate at 90 ° C. to prepare a support. At this time, the center line average roughness (Ra) of the surface was 0.65 μm. (Surface Treatment of Support) After the above treatment, the substrate was immersed in the following solution for treatment. Solution temperature 80 ° C. Vinylphosphonic acid 0.2% Polyvinylphosphonic acid 1.5% An aluminum plate was passed through the above solution for 30 seconds and dried. (Preparation of Photosensitive Planographic Printing Plate Materials 1 to 20) A photopolymerizable photosensitive layer coating solution having the following composition was applied on the above-mentioned surface-treated support with a wire bar so that the coating solution would have a dry weight of 1.4 g / m ^2. And dried at 95 ° C. for 1.5 minutes. After that, an overcoat layer coating solution having the following composition was further applied onto the photosensitive layer with an applicator so as to have a dryness of 2.0 g / m ² .
A photosensitive lithographic printing plate material 1 was prepared by drying at 75 ° C. for 1.5 minutes.

<Photopolymerizable Photosensitive Layer Coating Liquid> Polymer Binder A 35.0 parts Spectral sensitizing dye 1 (compound 7) 2.0 parts Spectral sensitizing dye 2 (compound 8) 2.0 parts IRGACURE 784 (Ciba Specialty Chemicals) 4.0 parts Polyfunctional urethane acrylate (NK oligo U-4HA: manufactured by Shin Nakamura Chemical Co., Ltd.) 40.0 parts Polyethylene glycol # 200 dimethacrylate (NK ester 4G: manufactured by Shin Nakamura Chemical Co., Ltd.) 10.0 parts Phthalocyanine pigment (MHI454: manufactured by Mikuni Dye Co., Ltd.) 6.0 parts 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (Sumilyzer) GS: Sumitomo 3M Co., Ltd.) 0.5 part Fluorine-based surfactant (F178K; Dainippon Ink and Chemicals Co., Ltd.) 0.5 part Methyl ethyl keto (Boiling point = 79.6 ° C.) 80 parts Cyclopentanone (boiling point = 129 ° C.) 820 parts <Overcoat layer (protective layer) coating liquid> Polyvinyl alcohol (GL-03: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 89 parts Water-soluble Polyamide (P-70: manufactured by Toray) 10 parts Surfactant (F1405: manufactured by Dainippon Ink and Chemicals, Inc.) 0.5 part Water 900 parts Further, in the preparation of the photosensitive lithographic printing plate material 1, a photopolymerizable photosensitive layer The polymer binder A of the coating liquid is replaced with the polymer binder B ~
Photosensitive lithographic printing plate materials 2 to 20 were produced in the same manner as in the preparation of photosensitive lithographic printing plate material 1 except that T was changed to T.

[0124]

[Chemical 3]

Example 1-2 Photosensitive planographic printing plate materials 1 to
Image formation and evaluation of 20 (image formation of photosensitive lithographic printing plate materials 1 to 20) For the photosensitive lithographic printing plate materials 1 to 20, a CTP exposure device (Tigercat: E) equipped with an FD-YAG laser light source was used.
Image exposure was carried out at a resolution of 2540 dpi (dpi represents the number of dots per inch, that is, 2.54 cm) by using CRM. Then, the heating device section before development,
A water washing part before removing the overcoat layer, a developing part filled with the following developer composition 1, a water washing part for removing the developer adhering to the plate surface, and a gum solution for protecting the image area (GW-3: manufactured by Mitsubishi Chemical Corporation. 1) and a CTP automatic developing machine (PHW23-V: manufactured by Technigraph) were used for development processing to form an image on the photosensitive lithographic printing plate material 1
Got ~ 20. At this time, the heating device section sets the plate surface temperature to 115
The temperature was set to 15 ° C. and the plate staying time was set to 15 seconds. The plate was inserted into the heating device of the automatic developing machine within 60 seconds after the exposure. Further, the temperature of the developing solution was 30 ° C.

Developer Composition 1 (Aqueous Solution Containing the Following Additives) A Potassium Silicate (Potassium Silicate) 8.0% by Mass Perex NBL: Kao Corporation 3.0% by Mass Caustic Potassium pH = 12.3 Adjustment (evaluation of the imaged photosensitive lithographic printing plate materials 1 to 20)
The following evaluations were performed on the image-formed photosensitive lithographic printing plate materials 1 to 20 obtained as described above. The evaluation results are shown in Table 2.

<< Sensitivity >> No film loss in the image area was observed, and the halftone dot exposure area of 175 lines and 50% was twice as light as the exposure quantity that could be reproduced 50% on the prepared lithographic printing plate surface. It was drawn and used as the sensitivity.

<< Reproducibility of Halftone Dots >> A photopolymerization type lithographic printing plate material having a size of 500 × 600 mm was subjected to full exposure and development of halftone dots of 175 lines and 50% at an appropriate exposure amount determined by the above sensitivity. The imaged halftone dot area was photographed with a 500 × optical microscope, the area of 9 points of the image part in the area of 2 mm × 2 mm was calculated, the average value 1 and the standard deviation 1 were calculated, and the standard deviation 1 was screened. It was used as an index of point reproducibility.

<Storage Stability> The photopolymerizable lithographic printing plate material was stored for 5 days in a thermostatic chamber at a temperature of 55 ° C. and a humidity of 50% in order to forcibly deteriorate the photopolymerizable lithographic printing plate material. The average value 2 and the standard deviation 2 were calculated by the same method as the point reproducibility. At this time, the value of average value 2−average value 1 and standard deviation 2−standard deviation 1 was used as an index of storage stability.

[0130]

[Table 2]

From the results shown in Table 2, it was found that the image-formed photosensitive lithographic printing plate materials 1 to 12 were excellent in sensitivity, halftone dot reproducibility and storage stability. It was also found that the photosensitive lithographic printing plate materials 9, 10, 11 and 12 are particularly excellent in sensitivity, halftone dot reproducibility and storage stability. Further, the developing solution for developing the image-formed photosensitive lithographic printing plate materials 1 to 12 has a low pH of 12.3,
It was found that the development sludge generation was suppressed.

Example 2-1 Photosensitive lithographic printing plate material 21
˜40 (undercoat layer treatment of support) On the surface-treated support produced in Example 1-1, an undercoat layer coating solution having the following composition was dried to 0.1 g / m ² . A wire bar was applied thereto to dry it, dried at 90 ° C. for 1 minute, and further heat-treated at 110 ° C. for 3 minutes to prepare an undercoated support.

<Undercoating Layer Coating Liquid> γ-methacryloxypropyltrimethoxysilane 1 part Methylethylketone 80 parts Cyclohexanone 19 parts (Preparation of photosensitive lithographic printing plate materials 21 to 40) Apply the photopolymerizable photosensitive layer coating liquid of the composition with a wire bar so as to be 1.4 g / m ² when dried,
It was dried at 95 ° C for 1.5 minutes. After that, an overcoat layer coating solution having the following composition was further dried on the photosensitive layer at a dry time of 2.0.
Apply with an applicator so that the g / m ² becomes 75 ° C.
And dried for 1.5 minutes to prepare a planographic printing plate material 21.

<Photopolymerizable Photosensitive Layer Coating Liquid> Polymer Binder A 42.5 parts Spectral sensitizing dye 1 (compound 7) 2.0 parts Spectral sensitizing dye 2 (compound 8) 2.0 parts IRGACURE 784 (Ciba Specialty Chemicals) 4.0 parts EO modified trimethylolpropane triacrylate (light acrylate TMP-6EO-3A: Kyoeisha Chemical Co., Ltd.) 42.5 parts Phthalocyanine pigment (MHI454: Mikuni pigment company) 6.0 parts 2 -T-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (Sumilyser GS: manufactured by Sumitomo 3M Ltd.) 0.5 part Fluorine-based surfactant (F178K; (Manufactured by Dainippon Ink and Chemicals, Inc.) 0.5 part Methyl ethyl ketone (boiling point = 79.6 ° C.) 80 parts Cyclopentanone (boiling point = 129 ° C.) 820 parts <Overcoat layer (protective layer) coating liquid> Polyvinyl alcohol (GL-03: manufactured by Nippon Synthetic Chemical Industry) 89 parts Water-soluble polyamide (P-70: manufactured by Toray) 10 parts Surfactant (F1405: Large) (Manufactured by Nippon Ink Kogyo Co., Ltd.) 0.5 part Water 900 parts Further, in the preparation of the photosensitive lithographic printing plate material 21, the polymer binder A of the photopolymerizable photosensitive layer coating liquid is replaced with the polymer binder B.
Photosensitive lithographic printing plate materials 22 to 40 were produced in the same manner as in the method for producing photosensitive lithographic printing plate material 21 except for changing to T.

Example 2-2 Photosensitive planographic printing plate material 21
To 40 (image formation of photosensitive lithographic printing plate materials 21 to 40) In the same manner as in Example 1-2, photosensitive lithographic printing plate materials 21 to 4
Image formation was performed at 0.

(Image-formed photosensitive lithographic printing plate material 21)
Evaluation of -40) Regarding the image-formed photosensitive lithographic printing plate materials 21 to 40 obtained as described above, Example 1-
The sensitivity, halftone dot reproducibility and storage stability described in 2 were evaluated. The evaluation results are shown in Table 3.

[0137]

[Table 3]

From the results shown in Table 3, it was found that the image-formed photosensitive lithographic printing plate materials 21 to 32 were excellent in sensitivity, halftone dot reproducibility and storage stability. It was also found that the photosensitive lithographic printing plate materials 29, 30, 31, 32 are particularly excellent in sensitivity, halftone dot reproducibility and storage stability. Further, it was found that the developing solution in which the image-formed photosensitive lithographic printing plate materials 21 to 32 were developed had development sludge suppressed while the developing solution had a low pH of 12.3.

Example 3-1 Photosensitive lithographic printing plate material 41
-46 (Preparation of photosensitive lithographic printing plate materials 41-46) Example 2-
The photopolymerizable photosensitive layer coating solution having the following composition was coated on the undercoated support described in 1 above with a wire bar so that the coating solution had a dry amount of 1.4 g / m ² , and dried at 95 ° C. for 1.5 minutes. . After that, an overcoat layer coating solution having the following composition was further applied onto the photosensitive layer with an applicator so that the dryness was 2.0 g / m ² , and dried at 75 ° C. for 1.5 minutes to perform photosensitive lithographic printing A plate material 41 was produced. Photopolymerizable photosensitive layer coating liquid Polymer binder A 42.5 parts Compound 9 0.7 parts Compound 10 0.7 parts Compound 11 0.7 parts Compound 12 0.7 parts Compound 13 0.7 parts Compound 140 0.7 parts Compound 15 0.7 parts EO-modified trimethylolpropane triacrylate (light acrylate TMP-6EO-3A: manufactured by Kyoeisha Chemical Co., Ltd.) 42.5 parts Phthalocyanine pigment (MHI454: manufactured by Mikuni Pigment Co., Ltd.) 6.0 parts 2- t-Butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (Sumilyser GS: Sumitomo 3M) 0.5 parts Fluorine-based surfactant (F178K; large) Made by Nippon Ink Chemical Co., Ltd. 0.5 part Methyl ethyl ketone (boiling point = 79.6 ° C.) 80 parts Cyclopentanone (boiling point = 129 ° C.) 820 parts <Over Coat layer (protective layer) coating liquid> Polyvinyl alcohol (GL-03: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 89 parts Water-soluble polyamide (P-70: manufactured by Toray Industries) 10 parts Compound 16 2 parts Surfactant (F1405: large) Made by Nippon Ink Industry Co., Ltd.) 0.5 parts Water 900 parts

[0140]

[Chemical 4]

Furthermore, in the preparation of the photosensitive lithographic printing plate material 41, the photopolymerizable photosensitive layer coating liquid was exposed to light except that the polymer binder A was changed to the polymer binders E, I, M, N and O. Photosensitive planographic printing plate materials 42 to 46 were prepared in the same manner as in the preparation of the photosensitive planographic printing plate material 41.

Example 3-2 Photosensitive planographic printing plate material 41
~ 46 image formation and evaluation (image formation of photosensitive lithographic printing plate materials 41-46) In Example 1-2, a CTP device equipped with an FD-YAG laser light source was installed, and an InGaN semiconductor laser with an oscillation wavelength of 405 nm was installed. Photosensitive lithographic printing plate materials 41 to 4 were prepared in the same manner as in Example 1-2, except that the device was changed to a self-made device.
Image formation of No. 6 was performed.

(Image-formed photosensitive lithographic printing plate material 41)
Evaluation of -46) The image-formed photosensitive lithographic printing plate materials 41 to 46 obtained as described above were used in Example 1-
The sensitivity, halftone dot reproducibility and storage stability described in 2 were evaluated. The evaluation results are shown in Table 4.

[0144]

[Table 4]

From the results shown in Table 4, it was found that the image-formed photosensitive lithographic printing plate materials 41, 42 and 43 were excellent in sensitivity, halftone dot reproducibility and storage stability. Further, it was found that the developing solution in which the image-formed photosensitive lithographic printing plate material 41, 42, 43 was developed had development sludge suppressed while the developing solution had a low pH of 12.3. It was

[0146]

According to the present invention, it is possible to provide a photosensitive lithographic printing plate material having good storage stability, excellent sensitivity and halftone dot reproducibility and high image performance, and an image forming method.

Claims (18)

[Claims] 1. A photosensitive material having, on a support, at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder. A lithographic printing plate material, which is image-wise exposed to light and photo-cures the photosensitive layer, and then a non-image portion of the photo-polymerizable photosensitive layer is removed from a support with a developer to form a photo-cured image. In the photosensitive lithographic printing plate material, the polymer binder has a weight average molecular weight (Mw) of 15,000 to 30,000.
And a monomer unit (A) having a carboxyl group and a unit (B) obtained by reacting at least a part of the monomer unit having a carboxyl group with an epoxy group-containing unsaturated compound, and B) 10
A photosensitive lithographic printing plate material, characterized in that the copolymer is contained in an amount of ˜30 mol%, and the imagewise exposure is followed by heat treatment and then development. 2. A photosensitive material having, on a support, at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder. A lithographic printing plate material, which is image-wise exposed to light and photo-cures the photosensitive layer, and then a non-image portion of the photo-polymerizable photosensitive layer is removed from a support with a developer to form a photo-cured image. In the photosensitive lithographic printing plate material, the polymer binder has an acid value of 60 to 110 mgKOH / g, and a monomer unit (A) having a carboxyl group and an epoxy group in at least a part of the monomer unit having the carboxyl group. A copolymer having a unit (B) obtained by reacting a contained unsaturated compound as a constituent and also containing 10 to 30 mol% of the above (B), which is developed after heat treatment after image exposure. Do the processing A photosensitive lithographic printing plate material characterized in that 3. A photosensitive material having at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder on a support. A lithographic printing plate material, which is image-wise exposed to light and photo-cures the photosensitive layer, and then a non-image portion of the photo-polymerizable photosensitive layer is removed from a support with a developer to form a photo-cured image. In the photosensitive lithographic printing plate material, the polymer binder has a weight average molecular weight (Mw) of 15,000 to 30,000.
And an acid value of 60 to 110 mgKOH / g, a monomer unit having a carboxyl group (A) and a unit (B) obtained by reacting at least a part of the monomer unit having a carboxyl group with an epoxy group-containing unsaturated compound. Is a copolymer containing 10 to 30 mol% of the above (B) as a constituent element, and is subjected to a development treatment after a heat treatment after the image exposure, Plate material. 4. The developer contains a silicate and has a pH of 1
It is 0.0-12.5, The Claims 1-3 characterized by the above-mentioned.
The photosensitive lithographic printing plate material as described in any one of 1. 5. The plate temperature of 100 to 13 in the heat treatment.
The photosensitive lithographic printing plate material according to any one of claims 1 to 4, which is performed at 0 ° C for 5 to 60 seconds. 6. The photosensitive lithographic printing plate material according to claim 5, wherein the heat treatment is performed within 300 seconds after image exposure. 7. The photosensitive lithographic printing plate material according to claim 1, further comprising an oxygen barrier layer on the photopolymerizable photosensitive layer. 8. The photosensitive lithographic printing plate as claimed in claim 1, wherein the support is an aluminum support which has been at least roughened and anodized. material. 9. The photosensitive lithographic printing plate material according to claim 8, wherein the support is an aluminum support which is further subjected to a hydrophilic treatment or an undercoating treatment. 10. A photosensitive material having at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder on a support. An image which forms a photocured image by imagewise exposing the planographic printing plate material to photocuring of the photosensitive layer and then removing the non-image portion of the photopolymerizable photosensitive layer from the support with a developer. In the forming method, the polymer binder has a weight average molecular weight (Mw) of 15000 to 30000, and at least a part of the monomer unit (A) having a carboxyl group and the monomer unit having the carboxyl group does not contain an epoxy group. A copolymer having a unit (B) obtained by reacting a saturated compound as a constituent and also containing 10 to 30 mol% of the above (B), which is subjected to heat treatment after image exposure and development treatment. An image forming method characterized by performing. 11. A photosensitive material having, on a support, at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder. An image which forms a photocured image by imagewise exposing the planographic printing plate material to photocuring of the photosensitive layer and then removing the non-image portion of the photopolymerizable photosensitive layer from the support with a developer. In the forming method, the polymer binder has an acid value of 60 to 110 mgKOH / g, and a monomer unit (A) having a carboxyl group and an epoxy group-containing unsaturated compound in at least a part of the monomer unit having the carboxyl group. Is a copolymer containing 10 to 30 mol% of the above-mentioned (B) as a constituent element, and is subjected to a development treatment after a heat treatment after the image exposure. Features Image forming method. 12. A photosensitive material having at least one photopolymerizable photosensitive layer containing an addition-polymerizable ethylenically unsaturated bond-containing monomer, a photopolymerization initiator and a polymer binder on a support. An image which forms a photocured image by imagewise exposing the planographic printing plate material to photocuring of the photosensitive layer and then removing the non-image portion of the photopolymerizable photosensitive layer from the support with a developer. In the forming method, the polymer binder has a weight average molecular weight (Mw) of 15,000 to 30,000, an acid value of 60 to 110 mgKOH / g, and has a monomer unit (A) having a carboxyl group and the carboxyl group. A copolymer having a unit (B) in which at least a part of a monomer unit is reacted with an epoxy group-containing unsaturated compound as a constituent, and containing 10 to 30 mol% of the (B). An image forming method, characterized in that after imagewise exposure, heat treatment is performed and then development treatment is performed. 13. The developer contains a silicate and has a pH of 1
It is 0.0-12.5, It is characterized by the above-mentioned.
13. The image forming method according to any one of 12. 14. The plate temperature of 100 to 1 in the heat treatment.
11. Performing for 5 to 60 seconds at 30 ° C. 11.
14. The image forming method according to any one of 13 above. 15. The image forming method according to claim 14, wherein the heat treatment is performed within 300 seconds after the image exposure. 16. The image forming method according to claim 10, further comprising an oxygen barrier layer on the photopolymerizable photosensitive layer. 17. The image forming method according to claim 10, wherein the support is at least a roughened and anodized aluminum support. 18. The image forming method according to claim 17, wherein the support is an aluminum support which has been further subjected to a hydrophilic treatment or an undercoat treatment.