JPH06344679A - Photosensitive planographic printing plate for proof and fixing sheet therefor - Google Patents

Abstract

PURPOSE:To prevent the involution of a printing plate in a form roller and obviate the application of water by applying hydrophilic treatment processing to the surface of a film support on the side opposite to the photosensitive layer provided on the support. CONSTITUTION:A photosensitive layer is provided on one surface of a film support and hydrophilic treatment processing is applied to the surface of the film support on the side opposite to the photosensitive layer to form a photosensitive planographic printing plate for proof. When proof is performed using the photosensitive planographic printing plate of the film support, a sheet wherein at least a single surface is composed of a self-adhesive rubber material is held between the surface plate of a proof press and the printing plate to perform proof. As the photosensitive compsn. contained in the photosensitive layer, there is a negative/positive type photo-crosslinkable photosensitive resin represented by a resin prepared by esterifying polyvinyl alcohol with cinnamic acid. As a concrete example of the film support, a biaxially stretached polyethylene terephthalate film is especially pref.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate used for proof printing by a flatbed proof printing machine and a method for closely fixing the printing plate on a surface plate of the flatbed proof printing machine. The present invention relates to a technique for preventing a lithographic printing plate for proof printing using a support such as polyethylene terephthalate film) from being caught in an ink inking roller.

[0002]

2. Description of the Related Art Conventionally, as a photosensitive lithographic printing plate used for proof printing by a lithographic printing press, a photosensitive lithographic printing plate having the same aluminum support as the plate used for this machine has been used. However, since the number of proofreading prints is extremely smaller than that of the printing by this machine, an inexpensive printing plate corresponding to it has been desired. As an example, a photosensitive lithographic printing plate having a film as a support has been used. Further, there is known a method of supplying water between the platen of the proofing machine and the printing plate to strengthen the adhesion between the two when the photosensitive lithographic printing plate whose support is a film is used.

[0003]

However, since the lithographic printing plate having a film as a support is not stiff, even if water is supplied between the platen of the flatbed proofing machine and the printing plate to bring them into close contact,
It has never been put to practical use because of problems such as being caught in the ink inking roller of the flatbed proofing machine due to ink tack.

Therefore, an object of the present invention is, firstly, to provide a technique for preventing the printing plate from being entrained in the ink replenishing roller in the proof printing by the flatbed proof printing machine, and secondly, to provide the printing plate. It is an object of the present invention to provide a technique for improving workability in which water is not required to be fixed on the surface plate.

[0005]

The first object of the present invention is achieved by the following items (1) to (3), and the second object is further achieved according to the items (1) to (3) below.

A photosensitive lithographic printing plate for proof printing having a photosensitive layer on one surface of a film support is characterized in that a surface of the film support opposite to the photosensitive layer is subjected to hydrophilic treatment. Photosensitive lithographic printing plate for proof printing.

A fixing sheet for a lithographic printing plate for proof printing, wherein at least one surface of the support is an adhesive rubber material.

When performing proof printing using the photosensitive lithographic printing plate of the film support, between the plate of the proofing machine and the printing plate,
A method of performing proof printing by sandwiching a sheet with adhesive rubber material on at least one side.

The present invention will be described in detail below.

As a support for the photosensitive lithographic printing plate for proof printing according to the present invention, a polyester film, particularly a biaxially stretched polyethylene terephthalate film is preferable in view of dimensional stability against water and heat, but an acetate film or polyvinyl chloride is preferable. Films, polystyrene films, polypropylene films, polyethylene films are also used and obtained.

The photosensitive layer is imagewise removed by imagewise exposure and development to form an image.

In the present invention, the photosensitive composition contained in the photosensitive layer is not limited, and various compositions can be used, and when exposed to actinic rays, its molecular structure chemically changes in a short time. The compounds include all compounds such as monomers, prepolymers, and polymers whose solubility changes in a solvent and, when a certain kind of solvent is applied, dissolves and removes an exposed portion or an unexposed portion. Examples of usable photosensitive compositions include a so-called negative / positive type in which the solubility in exposed areas is lowered, and a photocrosslinking type photosensitive agent represented by a polyvinyl alcohol esterified with cinnamic acid. Resin system, diazonium salt and its condensate are polyvinyl alcohol, polyvinylpyrrolidone,
There are systems mixed with polyacrylamide, etc., and systems mixed with a binder such as cyclized rubber using an aromatic azide compound as a photo-crosslinking agent. In addition, a photosensitive resin utilizing photoradical polymerization or photoionic polymerization should also be used. You can Further, as the so-called positive / positive type in which the solubility of the exposed portion is increased, there is, for example, a photosensitive resin composition containing o-quinonediazide as a photosensitive substance, and specifically, 1,2-benzoquinonediazide-4 -Sulfonyl chloride, 1,2-naphthoquinone doazide-4-sulfonyl chloride, 1,2-naphthoquinone diazide-5-sulfonyl chloride, 1,2-naphthoquinone diazide-6-sulfonyl chloride and a compound containing a hydroxyl group and / or an amino group A condensed compound can be used.

Examples of the hydroxyl group-containing compound include trihydroxybenzophenone, dihydroxyanthraquinone, bisphenol A, phenol novolac resin, resorcin benzaldehyde condensation resin and pyrogallol acetone condensation resin. Examples of the amino group-containing compound include aniline, p-aminodiphenylamine, p-
Examples include aminobenzophenone, 4,4'-diaminodiphenylamine, 4,4-diaminobenzophenone and the like.

Regarding the above-mentioned o-quinonediazide compound, J. KOSAR's "Light Sensitive System" (Wile
y & Sons, New York, 1965) and Nagamatsu, Inui "Photosensitive Polymer" (Kodansha, 1977).

Further, as a positive / positive type,
i) a compound capable of generating an acid upon irradiation with actinic rays, ii)
It is also possible to use a photosensitive resin composition containing a compound having at least one bond capable of being decomposed by an acid, and iii) a novolac resin containing two or three different phenols.

The content of the photosensitive composition in the photosensitive layer is preferably 5 to 80% by weight.

Further, as the binder constituting the photosensitive layer,
A polymer compound which is film-forming and solvent-soluble, and is preferably soluble or swellable in an alkali developing solution is used.

Specific examples of such polymer compounds include polymer compounds containing a structural unit having an aromatic hydroxyl group represented by the following general formula [I] in the molecular structure.

[0019]

[Chemical 1]

In the general formula [I], R ¹ and R ² are each a hydrogen atom, an alkyl group or a carboxyl group, R ³ is a hydroxyl atom, a halogen atom or an alkyl group, and R ⁴ is a hydrogen atom, an alkyl group or phenyl. Group or aralkyl group, X is a divalent organic group connecting a nitrogen atom and an aromatic carbon atom, and n
Is 0 or 1, and Y is a phenylene group which may have a substituent or a naphthylene group which may have a substituent.

Specific examples of the monomer forming the structural unit represented by the above general formula [I] include N- (4-hydroxyphenyl)-(meth) acrylamide and N- (2-hydroxyphenyl)-( (Meth) acrylamide, N- (4-hydroxynaphthyl)-(meth) acrylamide and other (meth) acrylamide monomers; o-, m- or p-hydroxyphenyl (meth) acrylate monomers; o-, m- or p -Hydroxystyrene monomer and the like can be mentioned. Preferably o-,
m- or p-hydroxyphenyl (meth) acrylate monomer and N- (4-hydroxyphenyl)-(meth) acrylamide monomer, more preferably N- (4-hydroxyphenyl)-(meth) acrylamide monomer.

Further, as a binder, a copolymer of a monomer forming the structure represented by the general formula [I] and the following monomers can be used.

[0023]

[Chemical 2]

Here, R ⁵ represents a hydrogen atom, an alkyl group or a halogen atom, and R ⁶ represents an alkyl group, a phenyl group or a naphthyl group.

The ratio of the group having an aromatic hydroxyl group represented by the general formula [I] in the above copolymer is preferably 1 to 30 mol%.

The proportion of the units formed from the acrylonitrile in the copolymer is 0 to 50 mol%.
Is preferable, and in view of developability, 5 to 40 mol% is preferable. The proportion of the structural unit formed from the above alkyl acrylates is preferably 50 to 95 mol% from the viewpoint of developability with a low alkaline aqueous solution, and further 60 to 95 mol% is the most suitable developability. give.

In addition to the above structural units, the above-mentioned structural units may be copolymerized with the above-mentioned acrylic acids such as acrylic acid or methacrylic acid for the purpose of finely adjusting the developability. Considering the development latitude, the proportion occupied in the polymer compound is preferably 0 to 20 mol%, and most preferably 0 to 10 mol%.

The weight average molecular weight of the polymer compound is
From the viewpoint of developability or resolution when a low alkaline aqueous solution is used as the developer, it is preferably 100 to 100,000, and more preferably 1000 to 30,000. These polymer compounds can be synthesized by a well-known copolymerization method.

Specific examples of such polymer compounds include copolymers having the following structures.

[0030]

[Chemical 3]

As a binder, a novolac resin obtained by polycondensation of at least one kind of phenol and an active carbonyl compound can also be used.

These phenols include all compounds in which at least one hydrogen atom bonded to the aromatic ring is substituted with a hydroxyl group, and specifically, for example, phenol,
o-cresol, m-cresol, p-cresol, 3,5-xylenol, 2,4-xylenol, 2,5-xylenol, carvacrol, thymol, catechol, resorcin, hydroquinone, pyrogallol, phloroglucin, alkyl group (carbon number) 1 to 8) substituted phenol and the like.

The active carbonyl compound includes, for example, aldehydes and ketones, and specific examples thereof include formaldehyde, acetaldehyde, benzaldehyde, acrolein, furfural and acetone.

As the polycondensation resin, phenol formaldehyde novolac resin, m-cresol formaldehyde novolac resin, phenol / m-cresol / formaldehyde copolycondensate resin, phenol / p-cresol / formaldehyde copolycondensate resin, m-cresol・ P-
Cresol / formaldehyde copolycondensate resin, o-cresol / p-cresol / formaldehyde copolycondensate resin, phenol / o-cresol / m-cresol / formaldehyde copolycondensate resin, phenol / o-cresol / p-cresol -Formaldehyde copolycondensate resin, phenol / m-cresol / p-cresol / formaldehyde copolycondensate resin, etc. may be mentioned.

The preferred novolac resin is phenol formaldehyde novolac resin, and the molecular weight is preferably in the range of 3500 to 500 in weight average molecular weight Mw and 1000 to 200 in number average molecular weight Mn.

The molecular weight of the resin is measured by GPC (gel permeation chromatography method).
The number average molecular weight Mn and the weight average molecular weight Mw are calculated by the method described in Morio Tsuge, Tatsuya Miyabayashi, and Masayuki Tanaka, “Chemical Society of Japan”, pages 800 to 805 (1972), to level the peaks in the oligomer region ( (Connect the center of the peak and the valley).

In the above novolak resin, a method for confirming the amount ratio of different phenols used in the synthesis is pyrolysis gas chromatography (PG
C) is used. Regarding pyrolysis gas chromatography, the principle, equipment and experimental conditions are, for example, edited by The Chemical Society of Japan, Shin Tsuge, New Experimental Course, Volume 19, Polymer Chemistry.
[I] pp. 474-485 (published by Maruzen in 1978) and the like. The method for qualitative analysis of novolak resins by pyrolysis gas chromatography is described by Morio Tsuge, Takashi Tanaka, and Masayuki Tanaka, "Analytical Chemistry," No. 18 Volume, pages 47-52 (1969).

Further, other polymer compounds usable as the binder include sulfoalkyl ester of (meth) acrylic acid (co) polymer, vinyl acetal (co) polymer, vinyl ether (co) polymer and acrylamide. (Co) polymers, styrene (co) polymers, cellulose derivatives and the like are also included.

These photosensitive layers are formed by a method known to those skilled in the art.
It is coated on the film support. In this case,
When finished as a printing plate, it is preferable that the film surface on which the photosensitive layer is coated is also subjected to a hydrophilizing treatment so that the non-image portion can easily receive dampening water during printing.

The hydrophilic treatment applied to the surface of the support opposite to the photosensitive layer of the lithographic printing plate for proof printing according to the present invention will be described below.

Hydrophilic treatment is performed with a polyester film,
A known technique for making the surface of a polyethylene film, a polypropylene film or the like hydrophilic can be applied. Examples of such techniques include hydrophilization treatment by surface oxidation, for example, corona discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation, etc .; hydrophilization treatment by surface unevenness, for example sand blasting, Examples include solvent treatment. Regarding these technologies, Hideo Marumoshi "Surface Chemistry of Polymers" (Sangyo Tosho, 1968) P.26-41, P.79-
84, P.88-99, and Plastic Film Study Group, "Plastic Film-Processing and Application-" (Gihodo, 1971) P.
90-95, P.105-122.

Known techniques can be applied to the processes such as development, washing, rinsing and desensitizing of the photosensitive lithographic printing plate for proof printing of the present invention.

When the lithographic printing plate prepared from the photosensitive lithographic printing plate for proof printing according to the present invention is placed on the surface plate of the lithographic printing plate, the surface of the lithographic printing plate which has been subjected to hydrophilic treatment is placed. The surface of the surface plate may be adhered by applying water between both surfaces.

Next, the fixing sheet used in the invention according to claims 2 and 3 will be described.

The fixing sheet is a sheet having a layer of an adhesive rubber material on at least one side of a support.

Natural rubber can be used as the adhesive rubber material, but synthetic rubber is preferable.

As the synthetic rubber, styrene / butadiene rubber, isoprene rubber, chloroprene rubber, urethane rubber, polysulfide rubber, tetrafluoroethylene / propylene rubber, acrylic rubber, epichlorohydrin rubber, ethylene vinyl acetate rubber, 1,2 -Polybutadiene rubber, thermoplastic elastomer (for example, styrene-based, olefin-based, urethane-based, polyester-based, polyamide-based, fluorine-based), ethylene / propylene copolymer, ethylene / propylene /
Examples thereof include a diene copolymer, nitrile / butadiene rubber, butyl rubber, fluororubber, chlorosulfonated polyethylene, propylene oxide rubber, ethylene / acrylic rubber, norbornene rubber, and silicone rubber, with silicone rubber being particularly preferable. You may use these together.

In the layer of tacky rubber material (shift prevention layer), (a) tackifying resin such as rosin, polyterpene, phenol resin, xylene resin, epoxy resin, petroleum carbonized resin, (b) phthalate ester, Adhesiveness to the sheet may be adjusted by adding a plasticizer such as phosphoric acid ester and chlorinated paraffin, and (c) oils and fats such as animal oil and mineral oil. Further, an antiaging agent, a stabilizer, a filler, a coloring agent and the like may be added.

As a silicone rubber suitable as a rubber contained in the slip-prevention layer, one containing a linear organic polysiloxane having a molecular weight of several thousand to several hundred thousand and having the following repeating units as a main component is preferable.

[0050]

[Chemical 4]

Here, n is an integer of 2 or more, and R is a carbon number of 1 to 1.
10 alkyl groups, halogenated alkyl groups, alkyl groups,
It is preferably a vinyl group or an aryl group, and 60% or more of R is a methyl group.

Silicone rubbers useful in the present invention include:
It is obtained by the condensation reaction of such a silicone base polymer, the following silicone base polymer, and the following silicone crosslinking agent.

[0053]

[Chemical 5]

Here, R has the same meaning as R described above, R'is an alkyl group such as a methyl group or an ethyl group, and Ac is an acetyl group.

These silicone rubbers are also available as commercial products, such as "YS-3085" manufactured by Toshiba Silicone Co., Ltd.

Other useful silicone rubbers are
Reaction of the above-mentioned base polymer with an H-type silicone oil having the following repeating units, or addition reaction with a silicone base polymer in which R is about 3% is a vinyl group, or the H-type silicone It can also be obtained by the reaction of oil comrades.

[0057]

[Chemical 6]

(In the formula, R has the same meaning as R above, and m
Is an integer of 2 or more, and n is an integer of 0 or 1 or more. ) In order to obtain a silicone rubber by such a crosslinking reaction, in addition to the above components, organic carboxylates of metals such as tin, zinc, cobalt, lead, calcium and manganese, for example, dibutyltin laurate and tin ( II) A catalyst such as octoate, cobalt naphthenate, or chloroplatinic acid is added.

Further, in order to improve the strength of the silicone rubber, it is possible to mix a filler.
Silicone rubber with pre-mixed fillers is commercially available as silicone rubber stock or silicone rubber version, and if coated,
When it is desired to obtain a slip-prevention layer made of a silicone rubber film, RTV or LTV silicone rubber dispersal is preferably used. In this way, for example, "Syl Off 23" and "SRX-25 manufactured by Torre Silicone Co., Ltd.
7 "," SH 237 "and other silicone coatings for paper coating are available.

The silicone rubber layer preferably further contains a silane coupling agent in order to improve the adhesiveness to the support.

Examples of the silane coupling agent are as follows.

[0062]

[Chemical 7]

These adhesive rubber materials are preferably used by coating or laminating on at least one side of a film support and used as a composite film sheet.

The photosensitive lithographic printing plate for proof printing of the present invention according to claim 1 can be applied to a known photosensitive lithographic printing plate not requiring fountain solution. In particular, it can be applied to a photosensitive lithographic printing plate which does not require fountain solution in which a photosensitive layer and a silicone rubber layer are laminated on a substrate or a primer layer on the substrate. For example, as described in JP-B-44-23042 and JP-B-46-16044, a dampening water-free photosensitive lithographic printing plate having a photo-soluble or photo-insoluble photosensitive layer and a silicone rubber layer laminated on a substrate, JP-A-48 -9
4504, JP-A-50-50102, a photosensitive lithographic printing plate in which a photo-adhesive photosensitive layer and a silicone rubber layer are laminated on a substrate, and a fountain solution is unnecessary, JP-A-55-55343, JP-A-2 -63050,
No. 2-63051, a photosensitive lithographic printing plate which does not require a fountain solution and has a protective layer having irregularities on a silicone rubber layer, JP-A-55-161244, JP-A-63-133153, and JP-A-63-153153. 62-50760
JP-A 1-172834, JP-A-2-34857, JP-A 1-118
No. 843, No. 1-150142, a photosensitive lithographic printing plate which does not require a fountain solution in which a primer layer, a photosensitive layer and a silicone rubber layer are laminated on a substrate, JP-A-56-80046 and 56-80047. It can be applied to a photosensitive lithographic printing plate which does not require fountain solution in which a photo-peeling photosensitive layer and a silicone rubber layer are laminated on the substrate described in 1.

Further, the photosensitive lithographic printing plate for proof printing of the present invention according to claim 1 is preferably applied to a photosensitive lithographic printing plate which does not require a fountain solution and can be developed with water or an aqueous developer or an aqueous alkaline developer. be able to. For example, JP-A-61-275759
, A surfactant, and a photosensitive lithographic printing plate that does not require a fountain solution and can be developed with a developer consisting of 30% or more water, JP-A-63-253949, 63-257748, and 63-280250
No. 63-280251, JP-A 1-159644, 1-214839.
No. 1-235955, No. 1-235956, a dampening having a photosensitive layer containing a polymer compound soluble or swellable in water or alkaline water, a photopolymerizable monomer, and a photopolymerization initiator. Examples include waterless photosensitive lithographic printing plates. Further, as a photosensitive lithographic printing plate which does not require a dampening solution, it is possible to use a photosensitive lithographic printing plate that does not require a dampening solution described in JP-A Nos. 2-282257 and 2-282258, for example, on a substrate. Or on the primer layer on the substrate, a monomer having an aromatic hydroxyl group, for example, N- (4-hydroxyphenyl)
A photosensitive layer containing a copolymer of acrylamide, p-hydroxystyrene, etc. and another monomer and a diazo resin, for example, a hexafluorophosphate salt of a condensate of p-diazodiphenylamine and formaldehyde is laminated to form a photosensitive layer. A photosensitive lithographic printing plate which does not require fountain solution and has a silicone rubber layer laminated thereon can be mentioned.

As the developer used for the dampening water-free photosensitive lithographic printing plate, a conventionally known water-based alkaline developer used for dampening water-free photosensitive lithographic printing plate can be appropriately used.

The aqueous alkaline developing solution is a developing solution containing water as a main component and is described in, for example, JP-A-61-275759, and contains 30% by weight or more of water, preferably 90% by weight. An aqueous alkaline developer containing an organic solvent, a surfactant, an alkali agent and the like in an amount of at least wt% can be mentioned.

As the organic solvent contained in the alkaline developer containing water as a main component, for example, aliphatic hydrocarbons (hexane, heptane, "Isopar EHG" (produced by Esso Chemical Co., Ltd., aliphatic hydrocarbons Brand name) 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) Tons, 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.) and the like.

As the surfactant added to the developer, anionic surfactants, nonionic surfactants, cationic surfactants and zwitterionic surfactants are used, which are described in Japanese Patent Application No. 2-206041. The surfactants mentioned are used. These surfactants can be used alone or in combination of two or more kinds. The amount of the surfactant used is 0.01 to 60% by weight, preferably 0.1 to 10% by weight.

Examples of the alkaline agent used in the developer include (1) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium di- or triphosphate or ammonium salt, and metasilicate. Inorganic alkaline agents such as sodium acid salt, sodium carbonate, ammonia, etc. (2) Mono, di or trimethylamine, mono, di or triethylamine, mono or diisopropylamine, n-butylamine, mono, di or triethanolamine, mono, di or tri Examples thereof include organic amine compounds such as isopropanolamine, ethyleneimine, and ethylenediimine. The amount of alkaline agent used is 0.05
%, Preferably 0.2% to 10% by weight is suitable.

[0071]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 Preparation of a photosensitive lithographic printing plate unnecessary for fountain solution One side of a polyethylene terephthalate film having a thickness of 300 μm was roughened by a sandblast method. The contact angle of the rough surface with water was 30 °.

A primer layer composition having the following composition was applied to the back surface of the roughened polyethylene terephthalate, and the temperature was adjusted to 85 ° C.
After drying for 3 minutes at 1000mJ using a 3kW ultra-high pressure mercury lamp
After exposing at / cm ² and drying at 100 ℃ for 4 minutes, the thickness is 5.0.
A μm primer layer was formed.

Primer layer composition diazo resin-1 9 parts (hexafluorophosphate of polycondensation product of p-diazodiphenylamine and paraformaldehyde, synthesized according to the method disclosed in JP-A-1-150142) Copolymer resin -1 91 parts (copolymer resin of 2-hydroxyethyl methacrylate, methyl methacrylate in a molar ratio of 34/66) Zinc oxide pigment 30 parts (FINEX-25 manufactured by Sakai Chemical Co., Ltd.) Yellow pigment 20 parts (KET-Yellow- 402 Dainippon Ink and Chemicals, Inc.) 3-methacryloxypropyltrimethoxysilane 3 parts Methyl lactate 847 parts Next, a photosensitive composition having the following composition is applied on the primer layer and dried at 85 ° C. for 2 minutes. To form a photosensitive layer having a thickness of 0.3 μm.

Photosensitive composition Diazo resin-1 50 parts Copolymer resin-2 50 parts (Copolymer of 2-hydroxyethyl methacrylate, N- (4-hydroxyphenyl) methacrylamide, methacrylic acid in a molar ratio of 35/60/5 Polymerized resin) Victoria Pure Blue BOH 1 part (Hodogaya Chemical Co., Ltd., dye) Methyl lactate 3900 parts Then, the following silicone rubber composition is applied on the above-mentioned photosensitive layer and dried at 85 ° C. for 10 minutes to obtain 1.8. A μm silicone layer was formed.

Silicone rubber composition α, ω-dihydroxypolydimethylsiloxane 100 parts (molecular weight 80,000) 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate 3.5 parts Dibutyl Sn dilaurate 0.8 parts Isopar E 800 parts ( Esso Kagaku Co., Ltd., isoparaffinic solvent) Toluene 100 parts Next, a polypropylene film having a thickness of 6 μm, one surface of which was matted, was laminated on the silicone layer to obtain a waterless photosensitive lithographic printing plate.

Next, a positive film was brought into vacuum contact with the silicone rubber layer, and then exposed using a metal halide lamp as a light source.

After the exposed plate material was immersed in the following developing solution for 1 minute, the surface of the plate material was rubbed with a pad impregnated with the following developing solution to remove the silicone rubber layer and the photosensitive layer in the image area. Got a printing plate.

Developer β-anilinoetal 0.5 part Propylene glycol 1.0 part p-tert-Butylbenzoic acid 1.0 part Potassium hydroxide 1.0 part Polyoxyethylene lauryl ether 0.1 part Potassium sulfite 2.0 parts Potassium metasilicate 3.0 parts Water 91 parts The above method The printing plate obtained in step 1 was set on a stool of a proofing machine with a thin layer of sponge coated with water. Then, proof printing was performed under the conditions shown in Table 1 below.

As a result, 100 good proof prints were obtained, but during that period, the proof plate was not caught in the ink roller.

[0081]

[Table 1]

Example 2 The same experiment as in Example 1 was carried out except that the following hydrophilic resin liquid was applied to a thickness of 0.2 μm instead of roughening in Example 1, and a calibration was performed during printing. The plate was not wound around the ink roller. The contact angle of water on the hydrophilically treated surface was 20 °.

Hydrophilic Resin Liquid Sebian-A-146 (Vinyl acetate latex, manufactured by Daicel Corp.) 50 g Water 150 g Example 3 Instead of polyethylene terephthalate in Example 1, 250 μm thick polypropylene, roughened Thickness 12 instead
An experiment similar to that of Example 1 was carried out except that a film of Boblon EX (biaxially stretched PVA film, manufactured by Nigo Film Co., Ltd.) having a thickness of μm was laminated, and the proof plate was not rolled into the ink roller during printing. There wasn't. The contact angle of water on the hydrophilized surface was 20 °.

Example 4 In Example 1, a printing plate was prepared without roughening one surface of polyethylene terephthalate, and instead of water, the following adhesive rubber sheet was used as a plate for the proofing machine and a printing plate. When an experiment similar to that of Example 1 was performed except that it was set in between,
The proof plate was not wound around the ink roller during printing.

Adhesive rubber sheet A sheet of 50 μm polyethylene terephthalate coated with a toluene solution of silicone rubber (“TSE-399” manufactured by Toshiba Silicone Rubber Co., Ltd.) on both sides to give a dry film thickness of 20 μm Comparative Example 1 When the same experiment as in Example 1 was conducted using the printing plate prepared in Example 4, when the ink roller first rolled into the printing plate, the printing plate was rolled into the ink roller, and even one sheet was printed. I couldn't get it.

The contact angle of water on the back surface of the film support is
It was 80 °.

[0087]

According to the present invention as set forth in claims 1 to 3, there is provided a photosensitive lithographic printing plate for proof printing, in which proof printing by a flat plate proof printing machine is improved, in which the printing plate is prevented from being wound around an ink replenishing roller. Provided. According to the present invention according to claims 2 and 3, water for fixing the plate is not required in the proof printing by the flatbed proof printing machine, thereby improving the workability of the proof printing.

Claims (3)

[Claims] 1. A photosensitive lithographic printing plate for proofing printing having a photosensitive layer on one surface of a film support, wherein the surface of the film support opposite to the photosensitive layer is subjected to hydrophilic treatment. A photosensitive lithographic printing plate for proof printing. 2. A lithographic printing plate fixing sheet for proof printing, wherein at least one surface of the support is an adhesive rubber material. 3. When performing proof printing using the photosensitive lithographic printing plate of the film support, between the plate of the proofing machine and the printing plate,
A method of performing proof printing by sandwiching a sheet with adhesive rubber material on at least one side.