JPH04276753A - Production of dampening waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To ensure superior removability of a silicone rubber layer and to suppress a change in performance after production. CONSTITUTION:A silicone rubber layer is formed on a photosetting photo-sensitive layer on a substrate by applying and drying a soln. capable of forming a silicone rubber layer. The resulting printing plate is uniformly exposed from the rubber layer side with active rays of light. This light is used by the quantity required to photo-degrade 0.1-20wt.% of a sensitizer contained in the photosensitive layer. The sensitizer is preferably diazo resin.

Description

Detailed Description of the Invention [0001] [Industrial Application Field] The present invention relates to a method for producing a photosensitive lithographic printing plate that does not require dampening water, and more specifically, a method for producing a photosensitive lithographic printing plate that has excellent developability,
Furthermore, the present invention relates to a method for producing a positive type photosensitive lithographic printing plate that does not require dampening water and exhibits little variation in performance after production. BACKGROUND OF THE INVENTION Conventionally, photosensitive lithographic printing plates that do not require dampening water, particularly positive type photosensitive lithographic printing plates that do not require dampening water, have been developed by Japanese Patent Publication No. 54-
No. 26923, Japanese Patent Publication No. 56-23150, Japanese Patent Publication No. 1983
It is known that a photocurable photosensitive layer and a silicone rubber layer are laminated on a support as described in various publications such as No. -52145, but these photosensitive lithographic printing plates that do not require dampening water In manufacturing, the components of each layer are dissolved in a suitable organic solvent, and the resulting solutions are sequentially applied onto a support and dried to form a layered film. Furthermore, this photosensitive lithographic printing plate that does not require dampening water,
Aging treatment is performed by post-heating if necessary. By the way, the adhesion between each layer of the photosensitive lithographic printing plate that does not require dampening water produced in this way may change over time after manufacture, and as a result, users often find that the photosensitive planographic printing plate that does not require dampening water changes. This may cause variations in the performance of lithographic printing plates. In addition, photosensitive lithographic printing plates that do not require dampening water generally have poor developability compared to PS plates, that is, the development process takes time and has poor working efficiency. Therefore, as a result of various studies regarding the above-mentioned problems, the present inventors formed an ink-repellent layer on the photocurable photosensitive layer in order to prevent changes in the adhesion between the layers, and then exposed the entire surface to actinic rays. It was discovered that the initial objective could be achieved by this, and the present invention was completed. OBJECTS OF THE INVENTION Therefore, an object of the present invention is to improve developability (
It is an object of the present invention to provide a method for producing a photosensitive lithographic printing plate that is excellent in removability of a silicone rubber layer (for example, removability of a silicone rubber layer, etc.) and does not require dampening water and has little variation in performance after production. [0006] The above object of the present invention is to form an ink repellent layer by coating and drying a solution containing an ink repellent substance on a photocurable photosensitive layer held on a support, and then exposing it to actinic rays. This can be achieved by a method for producing a photosensitive lithographic printing plate that does not require dampening water and is characterized by exposing the entire surface to light. The present invention will be explained in more detail below. In the present invention, an ink repellent layer is formed by coating and drying a solution containing an ink repellent substance on the photocurable photosensitive layer, and then the entire surface is exposed to actinic rays, thereby achieving excellent removability of the silicone rubber layer. Not only that, but also an excellent photosensitive lithographic printing plate that does not require dampening water and exhibits little variation in performance after production can be obtained. A silicone rubber layer is preferably used as the ink repellent layer. In the present invention, the amount of active light that is entirely exposed to the surface on which the ink repellent layer of the photosensitive lithographic printing plate that does not require dampening water is 0.1% by weight of the photosensitizer contained in the photosensitive layer. This is the amount of light necessary to photodecompose ~20% by weight, preferably 1% to 10% by weight. The actinic rays are particularly preferably ultraviolet rays. The photosensitive lithographic printing plate that does not require dampening water and produced in the present invention is developed into a lithographic printing plate, but the developer used for this development is one that does not have a swelling effect on the silicone rubber layer. Preferably, therefore, a developer containing 70% by weight or more of water is preferred. [0010] The organic solvent contained in this developer is as follows:
For example, aliphatic hydrocarbons (hexane, heptane, Isopar E, H, G (manufactured by Esso Chemical Co., Ltd., product name of aliphatic hydrocarbons or gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, xylene, etc.) , or halogenated hydrocarbons (tricrene, etc.), alcohols (methanol, ethanol, 1-butoxy-2-propanol, 3-methyl-3-methoxybutanol, β-anilinoethanol, benzyl alcohol, etc.), Ethers (methyl cellosolve, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, methyl carbitol, ethyl carbitol, butyl carbitol, dioxane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol dibutyl ether, propylene glycol, dipropylene glycol) butyl ether, tripropylene glycol methyl ether, polypropylene glycol methyl ether, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, 4-
methyl-1,3-dioxolan-2-one, etc.), esters (ethyl acetate, propyl acetate, hexyl acetate, methyl acetate, propyl acetate, diethyl succinate, dibutyl oxalate, diethyl maleate, benzyl benzoate, methyl cellosolve acetate) , cellosolve acetate, carbitol acetate, etc.). [0013] As the surfactant added to the developer used in the present invention, anionic surfactants, nonionic surfactants, cationic surfactants and amphoteric ionic surfactants are used. The surfactants described in specification No. 206041 are used. These surfactants can be used alone or in combination of two or more. The appropriate amount of the surfactant used in the present invention is 0.01% to 60% by weight, preferably 0.1% to 10% by weight. Further, it is preferable to add an inorganic or organic alkaline agent to this developer, and the amount of addition is preferably such that the pH is in the range of 9 to 13. It is also possible to dye the image area simultaneously with development by adding a dye such as crystal violet or astrazonelet to the developer. Development can be carried out, for example, by rubbing with a developing pad containing a developing solution as described above, or by pouring a developing solution onto the printing plate and then rubbing with a developing brush. By the above development, a printing plate is obtained in which the photosensitive layer and silicone rubber in the unexposed areas are removed, or a printing plate in which the silicone rubber layer is removed and the photosensitive layer is exposed, and the silicone rubber layer remains in the exposed areas. It will be done. There are various negative photosensitive materials used in the positive photosensitive lithographic printing plate that does not require dampening water in the production method of the present invention, and representative ones will be explained below. . (1) Photosensitive composition p- containing diazo resin
The diazo resin represented by the condensate of diazodiphenylamine and formaldehyde may be water-soluble or water-insoluble, but preferably those described in Japanese Patent Publication No. 47-1167 and Japanese Patent Publication No. 57-43890, etc. Those which are water-insoluble and soluble in ordinary organic solvents are used. Particularly preferred is a diazo resin represented by the following formula 1. [Formula 1] [In the formula, R1, R2 and R3 are
Represents a hydrogen atom, an alkyl group, or an alkoxy group, and R4
represents a hydrogen atom, an alkyl group or a phenyl group. X represents PF or BF4, Y represents -NH-, -S- or -
Indicates O-. ] The diazo resin is preferably used in combination with a film-forming resin, particularly a lipophilic polymer compound having a hydroxyl group. [0020] As such lipophilic polymer compounds,
In addition to those listed above, examples include copolymers of monomers having aliphatic hydroxyl groups in side chains, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, and other copolymerizable monomers. In addition to these, polyvinyl butyral resins, polyurethane resins, polyamide resins, epoxy resins, novolak resins, natural resins, etc. may be added as necessary. Various polymer compounds can be used as the binder used in combination with the diazonium salt, but monomers having an aromatic hydroxyl group as described in JP-A No. 54-98613 are preferable. , such as N-(4-hydroxyphenyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, o-, m-, or p-
Copolymers of hydroxystyrene, o-, m-, or p-hydroxyphenyl methacrylate and other monomers, as described in US Pat. No. 4,123,276. Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as main repeating units, natural resins such as shellac and rosin, polyvinyl alcohol, U.S. Patent Nos. 3 and 7
51,257, linear polyurethane resins as described in U.S. Pat. No. 3,660,097, phthalated resins of polyvinyl alcohol, condensed from bisphenol A and epichlorohydrin. It contains celluloses such as epoxy resin, cellulose acetate, and cellulose acetate phthalate. Examples of the alkali-soluble resins include novolac resins, vinyl polymers having phenolic hydroxyl groups, and condensation resins of polyhydric phenols and aldehydes or ketones described in JP-A-55-57841. . Examples of the novolac resin include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensation resin as described in JP-A-55-57841, and phenol-cresol-formaldehyde copolycondensation resin as described in JP-A-55-127553. p-substituted phenols and phenols as described or
Examples include copolymer resins of cresol and formaldehyde. In addition to the above-mentioned materials, these photosensitive compositions also contain pigments such as dyes and pigments, sensitizing agents, plasticizers, surfactants, organic acids, acid anhydrides, and exposure to light. A compound capable of generating an acid can be added. These binders are present in an amount of 40 to 99% by weight in the solid content of the photosensitive composition.
, preferably 50 to 95% by weight. The diazo resin is contained in an amount of 1 to 60% by weight, preferably 3 to 30% by weight. Other dyes, pigments such as pigments, fat-sensitizing agents, plasticizers, surfactants, etc. can be added to these photosensitive compositions. (2) -CH=C in the main chain or side chain of the polymer
Photosensitive composition containing a polymer compound having an H-CO- group Examples of such a polymer compound include polyesters containing -CH=CH-CO- as a photosensitive group in the main chain or side chain of the polymer; Those mainly composed of photosensitive polymers such as polyamides and polycarbonates (for example, U.S. Patent No. 3
(2-properidene)malonic acids such as cinnamylidenemalonic acid; Products whose main component is photosensitive polyesters derived from compounds and difunctional glycols (
For example, U.S. Patent Nos. 2,956,878 and 3,1
73,787); cinnamate esters of hydroxyl-containing polymers such as polyvinyl alcohol, starch, cellulose and the like (e.g. U.S. Patent No. 2,690,966;
Polymers such as those described in the specifications of the same No. 2,752,372, the same No. 2,732,301, etc. can be mentioned. These photosensitive compositions may contain other sensitizers, stabilizers, plasticizers, pigments, dyes, and the like. (3) Photopolymerizable composition comprising an addition polymerizable unsaturated compound This composition preferably comprises (a) a monomer having at least two terminal vinyl groups, and (b) a photopolymerization initiator. as well as(
c) Consisting of a polymer compound as a binder. The vinyl monomer of component (a) is as follows:
Special Publication No. 35-5093, No. 35-14719, No. 4
It is described in each publication of No. 4-28727. For example, acrylic or methacrylic esters of polyols, such as diethylene glycol (meth)acrylate, triethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, or methylene bis(meth)acrylamide. , bis(meth)acrylamides such as ethylene bis(meth)acrylamide,
Or an unsaturated monomer containing a urethane group, 003
0] For example, di-(2'-methacryloxyethyl)-2,
Diol mono(
Examples include reaction products of meth)acrylate and diisocyanate. As the photopolymerization initiator of component (b), the compound represented by the above formula 1 can be used, but other types can also be used. For example, the above-mentioned J. Examples include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreducible dyes, etc., as described in Chapter 5 of "Light Sensitive Systems" by Kosar. More specifically, it is disclosed in British Patent No. 1,459,563. As the photopolymerization initiator, the following can be used. Benzoin methyl ether, benzoin isopropyl ether, α,α-dimethoxy-
Benzoin derivatives such as α-phenylacetophenone, benzophenone, 2,4-dichlorobenzophenone, o-
Benzophenone derivatives such as methyl benzoylbenzoate, 4,4'-bis(dimethylamino)benzophenone, and 4,4'-bis(diethylamino)benzophenone; Thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone; 2 - Anthraquinone derivatives such as chloranthraquinone and 2-methylanthraquinone, acridone derivatives such as N-methylacridone and N-butylacridone, α,α-diethoxyacetophenone, benzyl, fluorenone, xanthone, uranyl compounds, halogen compounds, etc. Furthermore, as the binder for component (c),
A variety of known polymers can be used. Details of specific binders can be found in U.S. Patent No. 4,072,527.
It is stated in the number. In addition, the binder used when used in combination with the above-mentioned diazonium salt can be used. These photopolymerizable compositions can contain thermal polymerization inhibitors, plasticizers, dyes, pigments, and the like. (4) Photosensitive composition containing an azide group As the photosensitive azide compound, an aromatic azide compound in which the azide group is bonded to an aromatic ring directly or via a carbonyl group or a sulfonyl group is preferably used. . For example, polyazidostyrene, polyvinyl-p-azidobenzoate, polyvinyl-p-
Azidobenzal, reaction product of azidoarylsulfonyl chloride and unsaturated hydrocarbon polymer described in Japanese Patent Publication No. 45-9613, and Japanese Patent Publication No. 43-2101
No. 7, No. 44-229, No. 44-22954, No. 4
Examples include polymers having sulfonyl azide and carbonyl azide, as described in each publication of No. 5-24915. Among the negative photosensitive materials mentioned above, diazo photosensitive compositions are preferably used in the method of the present invention. A liposensitizing agent and a surfactant added to the photosensitive composition,
The amount of additives such as sensitizers, stabilizers, thermal polymerization inhibitors, plasticizers, and pigments such as dyes and pigments varies depending on the type, but in general, they are included in the photosensitive composition contained in the photosensitive coating solution. 0.01 to 20% by weight, preferably 0.05%
~10% by weight is suitable. Dyes preferably used in the present invention include basic dyes and oil-soluble dyes. Specifically, Victoria Pure Blue BOH, Victoria Blue BH, Methyl Violet, Eisen Malachite Green (manufactured by Hodogaya Chemical Industry), Patent Blue
Basic dyes such as Pure Blue VX, Rhodamine B, Methylene Blue (manufactured by Sumitomo Chemical), Sudan Blue II, Victoria Blue F4R
(All manufactured by B.A.S.F.) Oil Blue #603
, Oil Blue BOS, Oil Blue IIN (
As mentioned above, oil-soluble dyes such as those manufactured by Orient Chemical Industry Co., Ltd. are mentioned. The silicone rubber used in the present invention is a linear organic polymer having a repeating unit represented by the following formula 2 and having a molecular weight of several thousand to hundreds of thousands and a hydroxyl group in the main chain or at the end of the main chain. Those containing siloxane as a main component are preferred. [Formula 2] Here, n is an integer of 2 or more, and R has 1 to 1 carbon atoms.
10 alkyl groups, halogenated alkyl groups, alkoxyl groups, vinyl groups, aryl groups, silanol groups (OH groups)
It is preferable that 60% or more of R is a methyl group. The silanol group (OH group) may be located either in the main chain or at the end of the main chain, but is preferably located at the end. The silane coupling agent (or silicone crosslinking agent) used in the present invention is preferably one represented by the following formula 2. Formula 3 Rn SiX4-n (where n is an integer of 1 to 3, R represents a monovalent group of alkyl, aryl, alkenyl or a combination thereof, and these groups are halogen, It may have a functional group such as amine, hydroxy, alkoxy, aryloxy, thiol, etc. X is -OH, -OR2, -OAc, -O
-N=C(R2)R3, -Cl, -Br, -I
Represents a substitution notation such as. Here, R2 and R3 represent the same thing as R above, and R2 and R3 may be the same or different. Moreover, Ac represents an acetyl group. ) is a silane compound represented by That is, the silicone rubber useful in the present invention is obtained by a condensation reaction between such a silicone base polymer and a silicone crosslinking agent such as those listed above. Specific examples of the silane coupling agent used in the present invention include HN[(CH2)3Si(OM
e)3]2, vinyltriethoxylan, Cl(CH
2)3Si(OMe)3,CH3Si(OAc
)3, HS(CH2)3si(OMe)3, vinyltris(methylethylketoxime)silane, and the like. The silicone rubber described above is also available as a commercial product, such as YE-3085 manufactured by Toshiba Silicone Co., Ltd. Other useful silicone rubbers can be produced by reacting the above-mentioned base polymer with a silicone oil having a repeating unit represented by the following formula 4, or by reacting a silicone base polymer in which approximately 3% of R is a vinyl group. - It can also be obtained by addition reaction with a polymer or reaction between the silicone oils. [Formula 4] (wherein, R has the same meaning as R, which is a substituent of the polymer shown in Formula 1, m is an integer of 2 or more, and n is 0.
or an integer greater than or equal to 1. ) In order to obtain silicone rubber by such a crosslinking reaction, the crosslinking reaction is carried out using a catalyst. This catalyst includes tin, zinc, cobalt,
Organic carboxylates of metals such as lead, calcium, manganese, etc., such as dibutyltin laurate, tin(II) octoate, cobalt naphthenate, etc., or chloroauric acid, etc. are used. Further, in order to improve the strength of the silicone rubber and obtain a silicone rubber that can withstand the frictional forces generated during printing operations, a filler may be added. Silicone rubber mixed with filler in advance is commercially available as silicone rubber stock or silicone rubber dispersion, and when it is preferable to obtain a silicone rubber film by coating as in the present invention, RTV or LTV silicone rubber can be used. Dice version is preferred. Examples of this include Syl off 23 manufactured by Toray Silicone;
There are silicone rubber disk versions for paper coating such as SRX-257 and SH237. In the present invention, it is preferable to use a condensation crosslinking type silicone rubber. The silicone rubber layer preferably contains a silane coupling agent having an amino group in order to further improve adhesiveness. Examples of preferable silane coupling agents include the following. (a) H2 NCH2 CH2 NH(CH2)3
Si(OCH3)3(b)H2 NCE2 CH2
NH(CH2)3Si(OCH3)2(CH3
)(C)H2N(CH2)3Si(OE)3
However, E is an ethyl group. The silicone rubber layer used in the present invention may further contain a small amount of photosensitizer. The silicone rubber layer used in the present invention is prepared by dissolving silicone rubber in a suitable solvent, applying it onto the photosensitive layer, and drying it. The support used in the present invention is preferably one that is flexible enough to be set in a normal lithographic printing machine and that can withstand the load applied during printing, such as a metal plate made of aluminum, zinc, copper, steel, etc. and chromium, zinc,
Examples include metal plates plated or vapor-deposited with copper, nickel, aluminum, iron, etc., paper, plastic films, glass plates, resin-coated paper, paper covered with metal foil such as aluminum, and the like. Among these, preferred is an aluminum plate. The treatment for the support itself to improve the adhesion is not particularly limited, and includes surface treatments including various surface roughening treatments. Particularly in the case of aluminum plate supports,
It is preferable that surface treatments such as graining, anodizing, and, if necessary, sealing are performed. As a method for the above-mentioned graining treatment, a technique is adopted in which the surface of the aluminum plate or the like is degreased and then a brush polishing method, a ball polishing method, a chemical polishing method, an electrolytic etching method, or the like is applied. [0057] Further, the pore sealing treatment is performed using a sodium silicate aqueous solution,
It is carried out by immersion in a hot aqueous solution of hot water and some inorganic or organic salts, or by a steam bath. In the present invention,
The amount of photosensitive coating liquid applied to the support varies depending on the application, but is generally 0.5 to 3.5 g/m2 as solid content.
is appropriate. As a surface treatment, for example, a method of treating the surface of an aluminum plate with a silicate (US Pat. Nos. 2 and 7)
14,066), treatment with organic acid salts (U.S. Pat. No. 2,714,066), treatment with phosphonic acids and their derivatives (U.S. Pat. No. 3,220,832),
), a method of treatment with potassium hexafluorozirconate (U.S. Pat. No. 2,946,683), a method of anodizing, and a method of treating with an aqueous solution of an alkali metal silicate after anodization (U.S. Pat. No. 3,181). , No. 461). The above-mentioned anodizing treatment is carried out using an inorganic salt such as phosphoric acid, chromic acid, boric acid, or sulfuric acid, or an aqueous or non-aqueous solution of oxalic acid, sulfamic acid, etc. alone or in a mixture of two or more of these acids. This is done by passing an electric current through an aluminum plate or the like as an anode. The support may have a primer layer, and the primer layer may include, for example, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin, polyvinyl butyral resin,
Examples include epoxy resins, acrylate copolymers, vinyl acetate copolymers, phenoxy resins, polyurethane resins, polycarbonate resins, polyacrylonitrile butadiene, and polyvinyl acetate. [0061] To these primer layers, a compound that generates an acid upon exposure to light and a dye that changes color or fades when exposed to acid can be added. Further, as the anchor agent constituting the primer layer, for example, the silane coupling agent, silicone primer, etc. described above can be used, and organic titanates and the like are also effective. The thickness of each layer constituting the plate material of the present invention is as follows. That is, the support has a thickness of 50 to 400 μm, preferably 100 to 300 μm, and the photosensitive layer has a thickness of 0.05 to 10 μm.
m, preferably from 0.5 to 5 μm, and for the silicone rubber layer from 0.1 to 10 μm, preferably from 0.5 to 2 μm. In the present invention, a protective layer may be provided on the upper surface of the silicone rubber layer, if necessary. As the material for this protective layer, it is preferable to use a water-soluble film such as polyvinyl alcohol, a biodegradable film such as polyhydroxyalkanoate, or polyesteramide. [0064] Application methods for the coating liquid used in the production method of the present invention include dip coating, roll coating, reverse roll coating, air doctor coating, blade coating, rod coating, Meyer bar coating, knife coating, squeeze coating, and gravure coating. Methods such as coating, cast coating, curtain coating, extrusion coating, or using a spin coating device such as Whaler are used, and the coating film thickness is 0.1 to 5 g/m2.
is preferred. Further, the drying temperature is in the range of 20 to 150°C, preferably 30 to 100°C. [0065] A silicone rubber solution is applied onto the photosensitive layer in the same manner and heat-treated for several minutes, usually at a temperature of 100 to 120°C, to sufficiently cure the solution to form a silicone rubber layer. If necessary, a protective film can be provided on the silicone rubber layer using a laminator. Next, a method for manufacturing a printing plate that does not require dampening water using the plate material that does not require dampening water of the present invention will be explained. A positive film, which is the manuscript, is vacuum-adhered to the surface of the positive plate material and exposed. As a light source for this exposure, a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, etc., which generate abundant ultraviolet light, are used. Next, the positive film is peeled off and developed using a developer. As the developer, any known developer can be used for plate materials that do not require dampening water, but preferably an aqueous developer is used. It is also possible to dye the image area simultaneously with development by adding a dye such as crystal violet or astrazonelet to the developer. Development can be carried out, for example, by rubbing with a developing pad containing a developing solution as described above, or by pouring a developing solution onto the printing plate and then rubbing with a developing brush. By the above development, a printing plate is obtained in which the photosensitive layer and silicone rubber in the unexposed areas are removed, or a printing plate in which the silicone rubber layer is removed and the photosensitive layer is exposed, and the silicone rubber layer remains in the exposed areas. [Examples] The present invention will be explained in more detail below using Examples, but the present invention is not limited to these Examples. Example [Synthesis of diazo resin-1] 14.5 g (50 mmol) of p-diazodiphenylamine sulfate was mixed with 40.0 g of p-diazodiphenylamine sulfate under ice cooling.
Dissolved in 9g of concentrated sulfuric acid. Add 1.35g (4
5 mmol) of paraformaldehyde at a reaction temperature of 10
It was added gradually so as not to exceed ℃. This reaction mixture was added dropwise to 500 ml of ethanol under ice cooling, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was dissolved in 100 ml of pure water, and a cold concentrated aqueous solution containing 6.8 g of zinc chloride was added to this solution. After filtering the resulting precipitate,
It was washed with ethanol and dissolved in 150 ml of pure water. To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved. The resulting precipitate was collected by filtration, washed with water, and then dried to obtain diazo resin-1. The styrene-equivalent weight average molecular weight (Mw
) was 1500, and the number average molecular weight was 500. [Preparation of photosensitive lithographic printing plate that does not require dampening water] On a degreased aluminum plate with a thickness of 0.24 mm,
The following primer layer composition was applied at 60°C using a whirler and dried at 100°C for 2 minutes to form a primer layer. Note that the primer layer composition was dispersed using a high-pressure bulb homogenizer. [Primer layer composition] (1) Copolymer resin (M
w=4.0×104)
100 parts by weight (2) Pentaerythritol triacrylate
80 parts by weight (3) DE
TX (manufactured by Nippon Kayaku Co., Ltd.)
3 parts by weight [Chemical formula 1] (4) EPA (manufactured by Nippon Kayaku Co., Ltd.)
3 parts by weight [Chemical formula 2] (5) Kett Yellow 402 (manufactured by Dainippon Ink Co., Ltd.)
Yellow pigment) 8 parts by weight (6) Zinc oxide (average particle size
0.12μ)
20 parts by weight (7) Ethyl cellosolve

After coating and drying 920 parts by weight, exposure was performed using Unicure (manufactured by Ushio Inc.) at 160 W and 4 m/min. Next, the following photosensitive composition was applied onto the primer layer and dried at 80° C. for 2 minutes to form a photosensitive layer with a thickness of 0.3 μm. [Photosensitive composition] (1) Diazo resin-1
10
0 parts by weight (2) 2-hydroxyethyl methacrylate,
A copolymer resin (Mw
=4.2×104) 100 parts by weight (3) Orange IV

8 parts by weight (4
) Methyl lactate
90
0 parts by weight of the silicone rubber composition shown below was then coated on the photosensitive layer to a thickness of 2.0/m<2> and dried at 90 DEG C. for 10 minutes. [Silicone rubber layer composition] (1) Dimethylpolysiloxane having hydroxyl groups at both ends (molecular weight 52,000)
100
Part by weight (2) The following reactive silane compound
2.5 parts by weight [Chemical formula 3] (3) Dibutyltin dilaurate
0.8 parts by weight (4) Isopar E (manufactured by Esso Chemical)
900 parts by weight Next,
A 6 μm thick polypropylene film was laminated on the silicone rubber layer to obtain a photosensitive lithographic printing plate that did not require dampening water. This dampening water-free photosensitive lithographic printing plate was entirely exposed on the cover sheet using a metal halide lamp to photocure a portion of the photosensitive layer, thereby obtaining a dampening water-free photosensitive lithographic printing plate. Under these exposure conditions, the amount of light required to photodecompose about 3% of the photosensitizer in the photosensitive layer was about 10 mJ/cm2. Thereafter, this dampening water-free photosensitive lithographic printing plate was
Aging treatment was performed at 5°C for 3 days. After vacuum-adhering a positive film to the top surface of the thus obtained photosensitive lithographic printing plate that does not require dampening water,
400mJ/ using a metal halide lamp as a light source
An image of cm2 was exposed. Next, it was developed by immersing it in the following developer and rubbing it with a sponge. [Developer] (1) Potassium silicate (SiO2: 26%, K2O
:13.5%)

110 parts by weight (2) 5
0% potassium hydroxide aqueous solution
25 parts by weight (3) Propylene glycol
5 parts by weight [0
(4) Potassium sulfite

3 parts by weight (5) Tetrasodium ethylenediaminetetraacetate 0.3 parts by weight (6) Water

When 500 parts by weight was developed, the development time was only 50 seconds, although good results were obtained. Comparative Example In the above example, the total exposure amount was approximately 10 mJ/c.
When processing was carried out in the same manner as in the example except that the exposure of m2 was not performed, the developability was very poor and the time required for development was about 100 seconds. Furthermore, the number of clear steps of the step wedge was about two steps lower than in the example, and the practical sensitivity was also low. Effects of the Invention: As in the present invention, a solution containing an ink repellent substance is coated on a photocurable photosensitive layer, dried, and then the entire surface is exposed to actinic rays to improve developability, that is, to remove the silicone rubber layer. Therefore, it is possible to shorten the development time and has the excellent effect that there is little variation in performance after producing a photosensitive lithographic printing plate that does not require dampening water.

Claims (1)

[Claims] [Claim 1] An ink repellent layer is formed by coating and drying a solution containing an ink repellent substance on a photocurable photosensitive layer held on a support, and then the entire surface is exposed to actinic rays. A method for producing a photosensitive lithographic printing plate that does not require water.