JPH0553307A - Dampening waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To provide the above printing plate which obviates contamination at the time of printing and has excellent image reproducibility and plate wear by subjecting at least the surface on the side opposite from a photosensitive layer of a paper base to hydrophobing and/or lipophobing. CONSTITUTION:At least the surface on the side opposite from the photosensitive layer of the paper base of the dampening waterless photosensitive planographic printing plate constituted by successively laminating a primer layer, a photosensitive layer, a silicone rubber layer and a cover film layer on the base is subjected to the hydrophobing and/or lipophobing. The printing plate, etc., which have good plate wear and allow the use of an automatic printing machine are thus obtd. by using an inexpensive base, such as paper base. Namely, a resin or lipophiling finishing is used as the surface finishing of the paper base and such finishing may be executed on one surface or both surfaces of the base. Coatings of polyethylene, polypropylene, etc., are provided as the resin finishing. A wax finishing is used as the lipophiling and the paper surface is coated with paraffin, cetyl stearate, etc.

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 which does not require fountain solution, and more specifically, it is an inexpensive paper which can be processed by an automatic processor and has excellent printing durability. The present invention relates to a photosensitive lithographic printing plate that does not require a fountain solution using a support.

[0002]

BACKGROUND OF THE INVENTION Conventionally, as a photosensitive lithographic printing plate which does not require a fountain solution (hereinafter, referred to as a "plate material" if necessary), there is known one in which a photosensitive layer and an ink repellent layer are sequentially coated on a support. Has been. A printing plate can be obtained by exposing and developing this plate material. In such a plate material, an aluminum plate is usually used as a support, but since the aluminum support is generally high in cost, it becomes possible to select the support in the direction of using the cheapest material possible. As a result, it has been proposed to use polyethylene terephthalate as a support.

However, this polyethylene terephthalate support does not have sufficient adhesiveness with the coating layer,
The photosensitive lithographic printing plate or printing plate that does not require fountain solution thus obtained has problems that the silicone rubber layer is easily scratched and the printing durability is poor. On the other hand, as an inexpensive support, it is possible to use paper for the support, but in general, paper is vulnerable to an aqueous developing solution, and when developed with this, the paper support swells or is used for printing such as plate cleaners. Not only there is a problem that the paper is attacked by the chemicals used, but also the printing durability is very weak.

Therefore, as a result of various studies on the above problems, the present inventors have found that the above problems can be solved by processing the surface of the paper support, and have completed the present invention.

[0005]

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide an inexpensive fountain solution-free photosensitive lithographic printing plate using a paper support which has good printing durability and can be developed by an automatic processor. Especially.

[0006]

The above object of the present invention is to provide a photosensitive lithographic printing plate which does not require a fountain solution and which comprises a primer layer, a photosensitive layer, a silicone rubber layer and a cover film layer sequentially laminated on a paper support. This is achieved by a fountain solution-free photosensitive lithographic printing plate characterized in that at least the surface of the body on the side opposite to the photosensitive layer is made hydrophobic and / or oleophobic.

The structure of the present invention will be described more specifically below. According to the present invention, at least the surface of the paper support on the side opposite to the photosensitive layer is subjected to a hydrophobic treatment and / or an oleophobic treatment, so that an inexpensive support such as a paper support is used to obtain good printing durability. Moreover, it is possible to obtain a printing plate or the like that can be used by an automatic processor.

As the surface treatment of the paper support used in the present invention, resin treatment or oleophobic treatment is used, and these treatments may be performed on one side or both sides of the paper. For resin processing, polyethylene, polypropylene, polyvinyl chloride,
A coating of polycarbonate or the like is provided, and processing with polyethylene, polypropylene or polyvinyl chloride is particularly preferable.

Further, wax (wax) is used as an oleophobic treatment.
Processing is used and consists of coating the paper surface with paraffin, cetyl stearate, etc. The resin processing and the oleophobic processing may be used alone or in combination. Further, a mixture of both components may be coated.

In the present invention, specific methods for producing resin and oleophobic treatment on a paper support include a laminating method, resin solution coating, hot melt coating and the like. In the laminating method, a paper support and a thin plastic film are bonded together by heat, or a thin plastic film is bonded to a paper support while applying an adhesive (for example, synthetic rubber or epoxy resin). In this case, the adhesive may be applied to either the paper support or the thin plastic film.

The method of coating a resin solution is to dissolve a resin in a solvent, apply the resin on a paper support, and dry the resin. As the solvent, acetone, ethanol, trichlene, dioxane, tetrahydrofuran, cyclohexane or the like can be used. Can be mentioned. In the method by hot melt coating, a solid substance such as wax, polyethylene, and paraffin at room temperature is melted by heating and coated on a paper support. The thickness of the processed film obtained by processing the surface of the paper support is 0.1 to 2
It is 0 μm, preferably 0.5 to 10 μm.

The photosensitive layer used in the present invention may contain either a positive photosensitive composition or a negative photosensitive composition. The positive photosensitive composition contains an orthoquinone diazide group. The polymer compound containing an orthoquinonediazide group is mainly used herein, and the polymer compound containing an orthoquinonediazide group is a reaction product of a compound containing an orthoquinonediazide group and an alkali-soluble resin or a compound containing an orthoquinonediazide group and an alkali. It is used to mean either or both when it is a mixture with a soluble resin.

The typical ones will be described below. Examples of the polymer compound containing an orthoquinone diazide group include ester compounds of o-naphthoquinone diazide sulfonic acid and a polycondensation resin of phenols and aldehydes or ketones.

Examples of the above-mentioned phenols include monophenols such as phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, carvacrol and thymol, catechol, resorcin, hydroquinone and the like. Examples thereof include trihydric phenols such as dihydric phenol, pyrogallol, and phloroglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, furfural and the like. Preferred of these aldehydes are formaldehyde and benzaldehyde.

Further, examples of the above-mentioned ketone include acetone and methyl ethyl ketone. Specific examples of the polycondensation resin include phenol / formaldehyde resin, m-cresol / formaldehyde resin, m-, o- mixed cresol / formaldehyde resin, resorcin / benzaldehyde resin, pyrogallol / acetone resin and the like.

The condensation rate (reaction rate for one OH group) of o-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol of the o-naphthoquinonediazide compound is 15 to 8
0% is preferable, and 20 to 45% is more preferable.
Further, as the o-quinonediazide compound used in the present invention, the compounds described in JP-A-58-43451 can also be used.

Of the above o-quinonediazide compounds, 1, 2
-Benzoquinonediazide sulfonyl chloride or 1, 2
Most preferred is an o-quinonediazide ester compound obtained by reacting naphthoquinonediazidesulfonyl chloride with a pyrogallol-acetone condensation resin or 2,3,4-trihydroxybenzophenone.

As the o-quinonediazide compound used in the present invention, each of the above compounds may be used alone,
You may use combining 2 or more types of compounds. The polymer compound containing o-quinonediazide used in the present invention is
In consideration of coatability, those having a molecular weight of 1500 or more are preferable, and those having a molecular weight of 2000 or more are more preferable.

The above-mentioned o-quinonediazide compound is preferably used as a mixture with an alkali-soluble resin. Examples of the alkali-soluble resin include novolac resins, vinyl polymers having a phenolic hydroxyl group, condensation resins of polyhydric phenols and aldehydes or ketones described in JP-A-55-57841, and the like. Examples of the novolac resin include phenol / formaldehyde resin, cresol / formaldehyde resin, JP-A-55-5784.
Phenol / cresol / formaldehyde copolycondensation resin as described in JP-A-55-12.
Examples thereof include a copolycondensation resin of p-substituted phenol and phenol or cresol and formaldehyde as described in Japanese Patent No. 7553.

The vinyl polymer having a phenolic hydroxyl group is a polymer having a unit having the phenolic hydroxyl group in the molecular structure, and includes acrylamide, (meth) acrylic acid, styrene and acetal. , And polymers containing at least one structural unit such as maleic anhydride are preferred.

The polymer used in the photosensitive composition according to the present invention is preferably one having a copolymer type structure, and the monomer unit which can be used in combination with the above structural unit is, for example, ethylene or propylene. Ethylenically unsaturated olefins such as isobutylene, butadiene and isoprene, styrenes such as styrene, α-methylstyrene, p-methylstyrene and p-chlorostyrene, acrylic acids such as acrylic acid and methacrylic acid, for example itacone Unsaturated aliphatic dicarboxylic acids such as acid, maleic acid, maleic anhydride, etc., such as methyl acrylate, ethyl acrylate, -n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, acrylic acid-2
-Chloroethyl,

Phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate,
Esters of α-methylene aliphatic monocarboxylic acids such as ethyl ethacrylic acid, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide, such as acrylanilide, p-chloroacrylamide, m-nitroacrylanilide, m -Anilides such as methoxyacrylanilide, for example vinyl acetate, vinyl propionate, vinyl benzoate,

Vinyl esters such as vinyl butyrate, for example, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, for example 1-methyl-1-
Methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene,
Ethylene derivatives such as 1-methyl-1-nitroethylene, such as N-vinylpyrrole, N-vinylcarbazole,
There are N-vinyl type monomers such as N-vinylindole, N-vinylpyrrolidene and N-vinylpyrrolidone. These vinyl-based monomers are present in the polymer compound with a structure in which the unsaturated double bond is cleaved.

Of the above monomers, aliphatic monocarboxylic acid esters and nitriles are preferable because they exhibit excellent performance for the purpose of the present invention. These alkali-soluble resins preferably have a molecular weight of 1500 or more, more preferably 2000 or more, in consideration of coatability.

In addition to the above-mentioned materials, these photosensitive compositions may optionally contain dyes, pigments and other dyes, oil sensitizers, plasticizers, surfactants, organic acids, acid anhydrides, and light exposure agents. A compound capable of generating an acid can be added. There are various negative photosensitive materials used in the present invention,
A typical one will be described as described below.

(1) Photosensitive Composition Containing Diazo Resin The diazo resin represented by the condensation product of p-diazodiphenylamine and formaldehyde may be water-soluble or water-insoluble, but is preferably JP-B-47. -116
Water-insoluble and ordinary organic solvent-soluble substances such as those described in JP-A No. 7 and 57-43890 are used. Particularly preferred is a diazo resin represented by the following general formula [1].

[0027]

[Chemical 1]

[In the formula, R ¹ , R ² and R ³ represent a hydrogen atom, an alkyl group or an alkoxy group, and R ⁴ represents a hydrogen atom, an alkyl group or a phenyl group. X represents PF or BF ₄ , and Y represents -NH-, -S- or -O-. ]

The diazo resin is preferably used as a mixture with a film-forming resin, particularly a lipophilic polymer compound having a hydroxyl group. As such a lipophilic polymer compound, in addition to those listed above, a monomer having an aliphatic hydroxyl group in its side chain, such as 2-hydroxyethyl acrylate or 2
-Hydroxyethyl methacrylate and other copolymerizable monomers. Besides these,
If necessary, polyvinyl butyral resin, polyurethane resin, polyamide resin, epoxy resin, novolac resin, natural resin and the like may be added.

As the binder used in combination with the diazonium salt, various polymer compounds can be used, but preferably a monomer having an aromatic hydroxyl group as described in JP-A-54-98613. , N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide, o-, m-, or p-, for example.
Copolymers of hydroxystyrene, o-, m-, or p-hydroxyphenyl methacrylate with other monomers,

Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as main repeating units as described in US Pat. No. 4,123,276, natural resins such as shellac and rosin, polyvinyl alcohol, US Patent No. 3,7
51,257 polyamide resin, US Pat. No. 3,660,097 linear polyurethane resin, polyvinyl alcohol phthalated resin, bisphenol A and epichlorohydrin condensed Contains celluloses such as epoxy resin, cellulose acetate, and cellulose acetate phthalate.

Examples of alkali-soluble resins include novolac resins, vinyl polymers having phenolic hydroxyl groups, condensation resins of polyhydric phenols and aldehydes or ketones described in JP-A-55-57841. .. Examples of the novolak resin include phenol / formaldehyde resin, cresol / formaldehyde resin, phenol / cresol / formaldehyde copolycondensation resin as described in JP-A-55-57841, and JP-A-55-127553. P-substituted phenol and phenol as described, or
Examples thereof include copolymer resins of cresol and formaldehyde.

In addition to the above-mentioned materials, these photosensitive compositions may further contain, if necessary, dyes such as dyes and pigments, sensitizers, plasticizers, surfactants, organic acids, acid anhydrides, and exposures. A compound capable of generating an acid can be added. These binders are contained in the solid content of the photosensitive composition in an amount of 40 to 99% by weight, 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. These photosensitive compositions include other dyes,
Dyes such as pigments, oil sensitizers, plasticizers, surfactants and the like can be added.

(2) --CH.dbd.C in the main chain or side chain of the polymer
Photosensitive Composition Containing Polymer Compound Having H—CO— Group As such a polymer compound, polyesters containing —CH═CH—CO— as a photosensitive group in the main chain or side chain of the polymer, Those containing a photosensitive polymer such as polyamides and polycarbonates as a main component (for example, described in U.S. Pat. Nos. 3,030,208, 3,707,373 and 3,453,237). Such compounds);

Photosensitive polyesters derived from (2-properidene) malonic acid compounds such as cinnamylidene malonic acid and difunctional glycols as main components (eg, US Pat. No. 2,956,878 and Same 3rd
173,787 to a photosensitive polymer as described in each specification);

Cinnamic acid esters of hydroxyl group-containing polymers such as polyvinyl alcohol, starch, cellulose and the like (eg, US Pat. No. 2,690,966,
Polymers such as those described in each specification of No. 2,752,372, No. 2,732,301 and the like. These photosensitive compositions may contain other sensitizers, stabilizers, plasticizers, pigments, dyes and the like.

(3) Photopolymerizable Composition Comprising Addition-Polymerizable Unsaturated Compound This composition preferably comprises (a) a monomer having at least two terminal vinyl groups, and (b) a photopolymerization initiator. And (c) a polymer compound as a binder.

As the vinyl monomer of this component (a),
Japanese Patent Publication Nos. 35-5093, 35-14719, 4
It is described in each publication of 4-28727. For example, acrylic acid or methacrylic acid ester of polyol, that is, diethylene glycol (meth) acrylate, triethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, or methylenebis (meth) acrylamide. , Bis (meth) acrylamides such as ethylene bis (meth) acrylamide,
Or an unsaturated monomer containing a urethane group,

For example, a diol mono (meth) acrylate such as di- (2'-methacryloxyethyl) -2,4-tolylenediurethane or di- (2-acryloxyethyl) trimethylenediurethane and a diisocyanate. Examples include reaction products. As the photopolymerization initiator of the component (b), the compound represented by the general formula [1] can be used, but other types can also be used.

For example, the above-mentioned J. There are carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreducible dyes as described in Chapter 5 of "Light Sensitive Systems" by Kosar. More specifically, it is disclosed in British Patent No. 1,459,563.

The following may be used as the photopolymerization initiator. Benzoin methyl ether, benzoin isopropyl ether, α, α-dimethoxy-
Benzoin derivatives such as α-phenylacetophenone, benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone Benzophenone derivative,

Thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone, anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone, acridone derivatives such as N-methylacridone and N-butylacridone, α and α -Diethoxyacetophenone, benzyl, fluorenone, xanthone, uranyl compounds, halogen compounds and the like.

Further, as the binder of the component (c),
Various known polymers can be used. Specific binder details are described in US Pat. No. 4,072,527.
No. In addition, the binder used when used in combination with the above-mentioned diazonium salt is used. These photopolymerizable compositions may contain a thermal polymerization inhibitor, a plasticizer, a dye, a pigment and the like.

(4) Photosensitive Composition Containing Azido Group As the photosensitive azide compound, an aromatic azide compound having an azido group bonded to an aromatic ring directly or through a carbonyl group or a sulfonyl group is preferably used. ..

For example, polyazidostyrene, polyvinyl-p-azidobenzoate, polyvinyl-p- as described in US Pat. No. 3,096,311.
Azidobenzal, a reaction product of an azidoarylsulfonyl chloride with an unsaturated hydrocarbon polymer described in JP-B-45-9613, and JP-B-43-2101.
No.7, No.44-229, No.44-22954, No.4
Examples thereof include polymers having a sulfonyl azide or a carbonyl azide as described in JP-A Nos. 5-24915.

An oil sensitizer added to the photosensitive composition,
Additives such as surfactants, sensitizers, stabilizers, thermal polymerization inhibitors, plasticizers, and dyes such as dyes and pigments are generally contained in the photosensitive coating liquid, although the addition amount varies depending on the type. 0.01 to 20% by weight, preferably 0.05 to 10% by weight, is suitable for the photosensitive composition.

The dyes preferably used in the present invention include basic dyes and oil-soluble dyes. In particular,
Victoria Pure Blue BOH, Victoria Blue BH, Methyl Violet, Aizen Malachite Green (above, Hodogaya Chemical Co., Ltd.), Patent Pure Blue VX, Rhodamine B, Methylene
Basic dyes such as blue (above, manufactured by Sumitomo Chemical Co., Ltd.), as well as Sudan Blue II, Victoria Blue F4
R (above, BASF) Oil Blue # 60
3, oil blue BOS, oil blue IIN
(Above, manufactured by Orient Chemical Industry) and the like oil-soluble dyes.

The silicone rubber layer used in the present invention has a hydroxyl group in the main chain having a repeating unit represented by the following general formula [2] and a molecular weight of several thousand to several hundred thousand, or at the end of the main chain. Those containing a linear organic polysiloxane as a main component are preferable.

[0049]

[Chemical 2]

Here, n is an integer of 2 or more, R is a carbon number of 1 to
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 either in the main chain or at the end of the main chain, but is preferably at the end. As the silane coupling agent (or silicone crosslinking agent) used in the present invention, those represented by the following general formula [3] are preferable. General formula [3] R _n SiX _4-n

(In the formula, n is an integer of 1 to 3, R represents alkyl, aryl, alkenyl or a monovalent group in which these are combined, and these groups are halogen, amine, hydroxy, alkoxy, It may have a functional group such as aryloxy, thiol, etc. X is —OH, —OR ² ,
-OAc, -O-N = C ( R 2) R 3, -Cl, -B
Representation of substitution such as r and -I. Here, R ² and R ³ represent the same as the above R, and R ² and R ³ may be the same or different. Ac represents an acetyl group. ) Is a silane compound.

Thus, the silicone rubbers useful in the present invention are those obtained by the condensation reaction of such silicone base polymers with the silicone crosslinkers listed above.

A specific example of the silane coupling agent used in the present invention is HN [(CH ₂ ) ₃ Si (OMe).
₃ ] ₂ , vinyltriethoxylane, Cl (CH ₂ ) ₃ S
i (OMe) ₃ , CH ₃ Si (OAc) ₃ , HS (CH
₂ ) ₃ si (OMe) ₃ , vinyltris (methylethylketoxime) silane and the like.

The above silicone rubber is also available as a commercial product, such as YE-3085 manufactured by Toshiba Silicone Co., Ltd. Another useful silicone rubber is a reaction of the base polymer as described above with a silicone oil having a repeating unit represented by the following general formula [4],
Alternatively, it can also be obtained by an addition reaction with a base polymer of silicone in which about 3% of R is a vinyl group, or a reaction between the silicone oils.

[0055]

[Chemical 3]

(In the formula, R has the same meaning as R which is a substituent of the polymer represented by the formula 1, m is an integer of 2 or more, and n is 0.
Alternatively, it is an integer of 1 or more. ) In order to obtain a silicone rubber by such a crosslinking reaction, the crosslinking reaction is carried out using a catalyst. As this catalyst, 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 to obtain the silicone rubber which can withstand the frictional force generated during the printing operation, a filler can be mixed. The silicone rubber in which the filler has been mixed in advance is commercially available as a silicone rubber stock or a silicone rubber disc version. When it is preferable to obtain a silicone rubber film by coating as in the present invention, an RTV or LTV silicone rubber is used. The day version is preferred. As such an example, Syl off 23, SR manufactured by Torre Silicone Co., Ltd.
There are silicone rubber disk versions for paper coating such as X-257 and SH237.

In the present invention, it is preferable to use condensation-crosslinking type silicone rubber. The silicone rubber layer preferably contains a silane coupling agent having an amino group in order to further improve the adhesiveness.
Examples of preferable silane coupling agents include the following.

(A) H₂NCH₂CH₂NH (CH₂)₃Si (OCH₃)₃  (B) H₂NCE₂CH₂NH (CH₂)₃Si (OCH₃)₂(CH₃) (C) H₂N (CH₂)₃Si (OE)₃However, E is an ethyl group.

The silicone rubber layer used in the present invention may further contain a small amount of a photosensitizer. The silicone rubber layer used in the present invention is prepared by dissolving the silicone rubber in a suitable solvent and then coating and drying it on the photosensitive layer.

The support has a primer layer, and examples of the primer layer include polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin, polyvinyl butyral resin, epoxy resin, Examples thereof include acrylate-based copolymers, vinyl acetate-based copolymers, phenoxy resins, polyurethane resins, polycarbonate resins, polyacrylonitrile butadiene, polyvinyl acetate and the like.

To these primer layers, a compound which generates an acid upon exposure to light and a dye which discolors or fades due to an acid can be added. As the anchor agent forming the primer layer, for example, the above-mentioned silane coupling agent, silicone primer or the like can be used, and organic titanate or the like is also effective.

The thickness of each layer constituting the plate material of the present invention is as follows. That is, the support is 50 to 400 μm, preferably 80 to 300 μm, the photosensitive layer is 0.05 to 10 μm, preferably 0.5 to 5 μm, and the silicone rubber layer is 0.1 to 10 μm.
m, preferably 0.5 to 2 μm.

In the present invention, a protective layer, that is, a cover film may be optionally provided on the upper surface of the silicone rubber layer. As the material of the cover film, it is preferable to use a water-soluble film such as polyvinyl alcohol or a biodegradable film such as polyhydroxyalkanoate or polyesteramide. The plate material of the present invention that does not require dampening water is manufactured, for example, as follows.

An ordinary coater such as a reverse roll coater, an air knife coater, and a Mayer bar coater, or a spin coater such as a whaler is used to coat and dry the composition solution to form the primer layer on the support, followed by crosslinking and curing. Let Next, the composition solution for forming the photosensitive layer is applied and dried.

A silicone rubber solution is coated on the above-mentioned photosensitive layer in the same manner and heat-treated at a temperature of usually 100 to 120 ° C. for several minutes to be sufficiently cured to form a silicone rubber layer. If necessary, a protective film can be provided on the silicone rubber layer by using a laminator.

Next, a method for producing a printing plate that does not require dampening water using the plate material that does not require dampening water according to the present invention will be described. A positive film, which is an original, is brought into vacuum contact with the surface of a positive plate material and exposed. As the light source for this exposure, a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp or the like that generates abundant ultraviolet rays is used.

Then, the positive film is peeled off, and development is performed using a developing solution. As the developing solution, a known developing solution for a plate material which does not require dampening water can be used, but an aqueous developing solution is preferably used. The water-based developer is a developer containing water as a main component and is described in, for example, JP-A-61-257559, and contains 30% by weight or more of water.
A developer containing 50% by weight to 98% by weight, an organic solvent and a surfactant can be preferably used, and more preferably an alkaline agent is contained.

As the surface active agent added to the developing solution used in the present invention, anionic surface active agents, nonionic surface active agents, cationic surface active agents and zwitterionic surface active agents are used. Further, a dye such as crystal violet or astrazonelet may be added to the developing solution to dye the image area simultaneously with the development.

The development can be carried out, for example, by rubbing with a developing pad containing the above-mentioned developing solution or pouring the developing solution onto the plate surface and then rubbing it with a developing brush. By the above development, a printing plate from which the photosensitive layer and silicone rubber in the unexposed area have been removed or a silicone rubber layer has been removed to expose the photosensitive layer and a printing plate in which the silicone rubber layer remains in the exposed area can be obtained.

[0071]

The present invention will be described in more detail below with reference to examples of the present invention, but the present invention is not limited to these examples. Examples 1 to 10 (Synthesis of diazo resin-1) 14.5 g (50 mmol) of p-diazodiphenylamine sulfate was added to 40.9 under ice cooling.
g dissolved in concentrated sulfuric acid. 1.35 g (45
Of paraformaldehyde at a reaction temperature of 10 ° C.
Was added slowly so as not to exceed.

The reaction mixture was added dropwise to 500 ml of ethanol under ice cooling, and the resulting precipitate was filtered. After washing with ethanol, the 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 the solution. The generated precipitate was filtered, washed with ethanol, and dissolved in 150 ml of pure water.

To this solution 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 dried to obtain diazo resin-1.
Paper was used as the base support, and the coatings shown in Table 1 were applied to form Support-1 to Support-14.

Table 1 No. Base support processed film manufacturing method Film thickness Support-1 Paper, 150μ Polypropylene film for each 6μ Laminate processing (both sides) Support-2 Paper, 150μ PET film 5μ is attached with epoxy resin for each 5μ Resin adhesive Support -3 Paper, 150μ PVC dissolved in 0.5μ each tetrahydrofuran and dipped, then dried Support-4 Paper, 150μ PVC dissolved in 1μ tetrahydrofuran each, dipped and dried Support-5 paper, 150μ wax hot-melt coated 10μ each (lower layer only) Support-6 paper, 150μ PET coated with hot melt each 18μ (both sides) Support-7 paper, 150μ PET coated with hot melt each 5μ (both sides) support-8 paper, 150μ PET coated with hot melt 0.1μ each (both sides)

Table 1 (continued) No. Base support processed film manufacturing method Film thickness Support-9 Paper, 150μ PET coated with hot melt 10μ each (both sides) Support-10 Paper, 150μ PET coated with hot melt 23μ each (both sides) Support -11 Paper, 50μ PET coated with hot melt for each 5μ (both sides) Support-12 paper, 85μ PET coated with hot melt for each 5μ (both sides) Support-13 paper, 300μ PET coated with hot melt 5μ each (both sides) Support-14 paper, 400μ PET coated with hot melt each 5μ (both sides) Comparative support-1 paper, 150μ none

In Table 1, PET is polyethylene terephthalate and PVC is polyvinyl chloride. A primer layer composition having the following composition is applied to each of Support-1 to Support-14 and Comparative Support-1 formed as described above,
After drying at 85 ° C. for 3 minutes, the whole surface was exposed at 1000 mJ / cm ² using a 3 KW ultra-high pressure mercury lamp. 100 more
It was dried at 0 ° C. for 4 minutes to form a primer layer having a thickness of 0.8 μm.

[Primer Layer Composition] (1) Diazo Resin-18 (18 parts by Weight) (2) Copolymer Resin of 2-Hydroxyethyl Methacrylate and Methyl Methacrylate in a Molar Ratio 34/66 (92) Parts (3) Methyl Cellosolve 900 Then, a photosensitive composition having the following composition was applied to each support thus obtained and dried at 100 ° C. for 2 minutes to form a photosensitive layer having a thickness of 0.3 μm.

[Photosensitive Composition] (1) Diazo Resin-1 50 Parts (2) Copolymer Resin-1 50 of 2-Hydroxyethyl Methacrylate and N- (4-Hydroxyphenyl) methacrylamide in 20/80 Molar Ratio Parts by weight (3) Victoria Pure Blue BOH (dye manufactured by Hodogaya Chemical Co., Ltd.) 1 part by weight (4) Methyl Cellosolve 900 parts by weight Then, the following silicone rubber composition is dried on the photosensitive layer to give a dry film thickness of 1.8 g / m. ^It was applied so as to be ² and dried at 90 ° C. for 4 minutes.

[Silicone rubber layer composition] (1) Dimethylpolysiloxane having hydroxyl groups at both ends (molecular weight 82,000) 100 parts by weight (2) Triacetoxymethylsilane 10 parts by weight (3) Dibutyltin laurate 0.8 (4) Isopar E (manufactured by Esso Chemical Co., Ltd.) 900 parts by weight Next, a polypropylene film having a thickness of 6 μ and corona-treated on one side on the silicone rubber layer (manufactured by Honshu Paper Co., Ltd.,
Alfine EM201) was laminated to obtain a photosensitive lithographic printing plate not requiring dampening water.

A positive film was positioned on the upper surface of the above plate material and vacuum-contacted thereto, exposed using a metal halide lamp as a light source, and then the light transmissive film was peeled off.

Next, development was performed using an automatic developing machine [PSK-860 (Konica Corp., for PS plate)] using the following developing solution to remove the silicone rubber layer and the photosensitive layer in the unexposed area. A printing plate was obtained.

[Developer] β-anilinoethanol 0.5 part by weight propylene glycol 1.0 part by weight p-tert-butylbenzoic acid 1.0 part by weight potassium hydroxide 1.0 part by weight polyoxyethylene lauryl ether 0 1 part by weight Potassium sulfite 2.0 parts by weight Potassium metasilicate 3.0 parts by weight Water 91 parts by weight

Next, printing was performed under the following printing conditions, and the results are shown in Table 2. [Printing conditions] Printing machine: Heidel GTO (4 color machine, manufactured by Heidel) Printing ink: Dry color (red, yellow, black, indigo, manufactured by Toyo Ink) Printing paper: Coated paper (lightweight coated paper) Printing speed : 3000 rpm

Table 2 No. of color printed matter Plate finish quality after support development Printing durability Example 1 1 A ◎ 50,000 sheets Example 2 2 A ◎ 50,000 sheets Example 3 3 A ◎ 50,000 sheets Example 4 4 A ◎ 50,000 sheets Example 5 5 A ◎ 49000 Sheet Example 6 6 A ◎ 45000 sheets Example 7 7 A 0 45000 sheets Table 2 (continued) No. of color printed matter Plate finish quality after support development Printing durability Example 8 8 A ◎ 40000 sheets Example 9 9 A ◎ 50,000 sheets Example 10 10 A ◎ 50,000 sheets Example 11 11 A 〇 50,000 sheets Example 12 12 A ◎ 50,000 Sheet Example 13 13 A ◎ 50,000 sheets Example 14 14 A 〇 50,000 sheets Comparative Example 1 Comparative 1 B × 30,000 sheets

In Table 2, in the plate after development, A represents no deformation even after development, and B represents deformation after development. In terms of finish quality, ⊚ indicates a good printed matter, ∘ indicates a slightly good printed matter, and x indicates a defective printed matter with color misregistration.

As is clear from Table 2, the plate after development is not deformed in Examples 1 to 14 of the present invention, whereas the comparative support 1 of Comparative Example 1 is deformed. .. In addition, the finished quality of the color printed matter is good, whereas in Comparative Example 1, color misregistration occurs and only poor printed matter can be obtained. Further, the printing durability is 15,000 sheets in Comparative Example 1, whereas 35,000 sheets to 4500 sheets in the present invention.
Excellent printing durability with 0 sheets.

[0087]

INDUSTRIAL APPLICABILITY According to the present invention, a printing plate obtained by subjecting at least one side of a paper support to a hydrophobic treatment or an oleophobic treatment can be developed by an automatic processor and has a printing durability. It has an excellent effect of being good.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinichi Matsubara 1 Sakura-cho, Hino-shi, Tokyo Konica Co., Ltd. (72) Inventor Hiroshi Tomiyasu 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd. In-house (72) Inventor Akio Kasakura 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd.

Claims (1)

[Claims] 1. A photosensitive lithographic printing plate which does not require a fountain solution, which comprises a primer layer, a photosensitive layer, a silicone rubber layer and a cover film layer, which are sequentially laminated on a paper support, and is opposite to at least the photosensitive layer of the paper support. A photosensitive lithographic printing plate that does not require fountain solution, characterized in that its side surface is processed to be hydrophobic and / or oleophobic.