JPH043165A - Lithographic printing plate material that does not require dampening water - Google Patents

Abstract

PURPOSE:To well maintain small dot reproducibility by incorporating a yellow dye into a photosensitive layer. CONSTITUTION:This printing plate has a primer layer, the photosensitive layer and a silicone rubber layer on a base and the yellow dye is incorporated into the photosensitive layer. While various kinds of known dyes, such as acid dyes, reactive dyes, pH indicators, and dyes for food, are usable as the yellow dye to be incorporated into the photosensitive layer, the oil-soluble dyes are more preferable. Since the yellow dyes are incorporated into the photosensitive layer in such a manner, the sensitivity is not so much high and the halation by the reflected light from the base is prevented; in addition, the sensitivity to image exposing is not so high and, therefore, the exposing is not hindered and the excellent small dot reproducibility is obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lithographic printing plate material that does not require dampening water.
This invention relates to a lithographic printing plate material that does not require dampening water and has excellent dot reproducibility.

[Conventional technology]

A dampening water-free lithographic printing plate #4 (hereinafter abbreviated as "1 plate material if necessary") having a photosensitive layer and a silicone rubber layer on a support to a dampening water-free planographic printing plate (hereinafter referred to as "plate material 1" as needed) To obtain a printing plate (abbreviated as "printing plate"), a manuscript, such as a positive film, is vacuum-adhered to the surface of the plate material, exposed to light using, for example, a metal halide lamp, and then developed with a developer to remove silicone rubber from the unexposed areas. By removing only the layer and the photosensitive layer or the silicone rubber layer, it is possible to obtain a printing plate in which the recessed image area is formed.

Conventionally, Japanese Patent Publication No. 56-12861 discloses that by containing a yellow pigment (reflectance at 400 nm of 30% or more) in the photosensitive layer, light reflected from the support below the photosensitive layer is cut and halation is prevented. Techniques have been disclosed to prevent this and improve spot reproducibility.

Furthermore, Japanese Patent Application Laid-Open No. 188947/1988 discloses a technique in which a photosensitive layer contains a PH indicator.

[BH3 that the invention aims to solve] However, when a yellow pigment is contained in the photosensitive layer, there is a drawback that the high sensitivity causes image exposure areas that are not reflected light to be canted, resulting in insufficient spot reproducibility. .

Furthermore, there is a drawback that even if a pH indicator is included, it hardly contributes to small-point reproducibility.

Therefore, an object of the present invention is to provide a lithographic printing plate material that does not require dampening water and can maintain good dot reproducibility.

[Means to solve the problem]

The name of the present invention was arrived at as a result of intensive studies to achieve the above object.

That is, the dampening water-free planographic printing plate material according to the present invention is a dampening water-free planographic printing plate material having a primer layer, a photosensitive layer, and a silicone rubber layer in this order on a support, wherein the photosensitive layer contains a yellow dye. It is characterized by containing.

In a preferred embodiment of the invention, both the photosensitive layer and the primer layer contain a yellow dye.

[Structure of the invention]

The present invention will be explained in detail below.

The lithographic printing plate material that does not require dampening water of the present invention has a primer layer, a photosensitive layer, and a silicone rubber layer on the other side of the support, and if necessary, an adhesive layer is provided between the photosensitive layer and the silicone rubber layer. The photosensitive layer and the silicone rubber layer, which may have a light-transmitting film layer on the silicone rubber layer, may be a single photosensitive silicone rubber layer.

(Support) The support is preferably one that is flexible enough to be set in a normal lithographic printing machine and that can handle the load applied during printing, such as metal plates such as aluminum, zinc, copper, and steel, and chrome. Metal plates plated or vapor-deposited with zinc, copper, nickel, aluminum, iron, etc. are preferable, and paper, plastic films and glass plates, resin-coated paper,
Paper covered with metal foil such as aluminum, plastic film treated to make it hydrophilic, etc. may also be used.

Among these, aluminum plates are preferred. When using an aluminum plate, it may be subjected to surface roughening treatment such as graining treatment and anodizing treatment.

The thickness of the support is preferably 50 to 400 g.
More preferably, it is 100 to 300 μm.

(Puty layer) For the primer layer, a resin, a silanker 7 pulling agent, a silicone primer, etc. can be used, and an organic titanate or the like is preferably used.

Examples of resins include polyester resin, vinyl chloride, etc.
Vinyl acetate copolymer, acrylic resin, vinyl chloride resin,
Examples include polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, fairoxy resin, polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, and the like.

The primer layer used in the present invention is preferably crosslinked in order to improve solvent resistance to the coating solvent of the photosensitive layer and the organic solvent of the developer.

Components to be crosslinked include polyvalent incyanate compounds, diazo resins, and multivalent epoxy compounds.

A compound having two or more polymerizable ethylenically unsaturated double bonds is used. Examples of polyvalent incyanate compounds include diphenylmethane 4,4'-one isocyanate, hexamethylene diisocyanate, coronate E, I (L, E)! (manufactured by Nippon Polyurethane Kogyo Co., Ltd., polyvalent incyanate compound), and the like. The diazo resins include 4-diazodiphenylamine, phosphorus hexafufluoride mki2-polmaldehyde resin, 3-methoxy-diphenylamine-4-diazonium salt and 4,4'-bis-
Examples include mesitylene sulfonate-enriched condensates of methoxymethyl-diphenyl ether.

Examples of the polyvalent epoxy compound include bisphenol epoxy resin, bisphenol F diglycidyl ether, nopolar glycidyl ether, hexahydrophthalic acid glycidyl ether, triglycidyl isocyanurate, and the like.

Examples of compounds having two or more polymerizable ethylenically unsaturated double bonds include trimethylolpropane triacrylate, te)-ramethylolmethane triacrylate,
Examples include allyl acrylate, 1,4-butanediol dimethacrylate, etc. When a compound having an ethylenically unsaturated double bond is used, a polymerization initiator or a photopolymerization initiator is used in combination.

Among the above crosslinking agents, diazo resins are preferred.

(Photosensitive layer) As the yellow dye contained in the photosensitive layer, various known dyes such as acid dyes, reactive dyes, PI (indicators, and food dyes) can be used, but oil-soluble dyes are preferred.

Commercially available examples of such dyes include Kayalax Yellow, Kayakryl Yellow, Kayalan Yellow, Kayalon ψ Polyester-Yellow, Kayalon Polyester Ink Plilo Flavin 5 Kayalon φ.
Polyester φ Light Yellow, Kayalon-77 Stroke Yellow, Kayaku Chrysophenine (made by Nippon Kayaku ■), Sumikacryl Yellow, Sumikalon Yellow Sumifix Yellow (made by Sumitomo Chemical ■), Solar φ Pure e Yellow, Diani 7x Life Yellow, Tairenren Yellow, Mikasion φ Yellow, Mikasion-Brilliant e Yellow, Diace Z Noton Fast Yellow, Taiyashi, Dofast Yellow, Diacryl Φ Yellow, Diacryl Kai Golden Ye 0-, Diacryl -Fast Yellow Diacrylic Brilliant Yellow σ-, Diamira Yellow (manufactured by Mitsubishi Kasei ■), and the like.

In addition to yellow pigments, compounds that exhibit a yellow color when dissolved in a solvent (for example, aromatic nitro compounds such as dinitrophenol) or compounds that absorb ultraviolet light of 450 nm or less (ultraviolet absorbers) may also be used. good.

In the present invention, 11 yellow pigments are selected from among the above compounds!
Or two or more types can be selected and used.

The content of the yellow dye is preferably 30 to 0.01 parts by weight, more preferably 15 to 0.01 parts by weight, based on the solid content of the photosensitive layer.

The uninvented photosensitive layer may contain m-hull together with a yellow dye.

As the photosensitive material used in the photosensitive layer, diazo resin resin is preferably used.

Examples of the diazo resin include salts of condensates of 4-diazodiphenylamine and formaldehyde or acetaldehyde, such as hexafluorophosphate tetrafluoroborates, perkM salts, or periodates formed by reaction with the above condensates. Diazo resin inorganic salt, which is a product, and U.S. Patent 3,30
Examples include diazo resin organic salts, which are reaction products of the above condensate and sulfonic acids, as described in No. 0,309. Particularly preferred is the PF6 salt of a condensate of 4-diazodiphenylamine and paraformaldehyde.

The diazo resin is used in conjunction with a binder. Various polymeric compounds can be used as such a binder, but preferably disclosed in Japanese Patent Application Laid-Open No. 54-98813
Monomers having aromatic hydroxyl groups such as those described in hydroxystyrene,
Copolymers of 0-, 1- or p-hydroxyphenyl methacrylate, etc. with other monomers, U.S. Pat. No. 4,123
Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as a main repeating unit, natural resins such as shellac, rosin, polyvinyl alcohol, as described in U.S. Pat. No. 3,751,257, 27[1i] Polyamide resins as described, linear polyurethane resins as described in U.S. Pat. No. 3,880,097, phthalated resins of polyvinyl alcohol, epoxy resins condensed from bisphenol A and shrimp cumylhydrin, cellulose acetate, cellulose Included are celluloses such as acetate phthalate.

A preferable binder is one containing an alcoholic OH group in a monomer composed of an acrylic copolymer, and the content of the alcoholic OH group is 10 to 90 vao.
f1% is preferred.

The content of the diazo resin in the photosensitive composition is 10 to 50% by weight, more preferably 20 to 40% by weight. Moreover, the blending amount of the above-mentioned binder is 45 to 8 in the photosensitive composition.
0% by weight, preferably 50-70% by weight.

In the photosensitive layer of the present invention, in addition to the above-mentioned diazo resin, a quinonediazide type positive photosensitive material such as a conventionally known 0-naphthoquinone cyasito compound may be used as a photosensitive material.

Suitable 0-naphthoquinonediazide compounds include naphthoquinone-(1,2)-diazide-(2)-sulfonic acid chloride and phenol or talesol-formaldehyde resins as described in U.S. Pat. No. 3,048,120. There are esters of Other 0-naphthoquinone diazide compounds include, for example, U.S. Pat.
Ester of billow no-acetone resin and 0-naphthoquinonediazide sulfonic acid chloride described in No. 635,709, JP-A-55-76346, No. 58
-1044 and polyhydroxyphenyl resin described in No. 58-1045. -Ester of naphthoquinone cyasitosulfonic acid chloride, JP-A-11-1989
A homopolymer of p-hydroxystyrene as described in No. 3305 or a copolymer of this with other copolymerizable monomers and ester-reacted with 0-naphthoquinone cyacytosulfonic acid chloride. −
17481, a reaction product of a polymer product of a styrene monomer and a phenol derivative and 0-quinonediazide sulfonic acid, and a reaction product of a polymer product of a styrene monomer and a phenol derivative described in No.
-Esters of naphthoquinonediazide sulfonic acid chloride and the like.

As a suitable binder for use in a photosensitive composition containing such a quinonediazide type photosensitive substance, for example, an alkaline aqueous solution-soluble 7-porak resin can be mentioned. Representative examples of such novolac resins include phenol-formaldehyde resin, cresol-formaldehyde resin, p-tart-butylphenol-formaldehyde resin, and phenol-modified xylene resin.

The amount of quinonediazide compound in the photosensitive composition is 10-5
It is 0% by weight, more preferably 20 to 40% by weight. Further, the amount of the binder blended in the photosensitive composition is 4
It is 5 to 80% by weight, preferably 50 to 70% by weight.

Also, -CH=C as a photosensitive group in the main chain or side chain of the polymer.
Those whose main component is a photosensitive polymer such as polyesters containing H-C-, polyamides VIII, and polycarbonates are also used. For example, JP-A-55-404
15, photosensitive polyesters obtained by condensation of phenylene diethyl acrylate with hydrogenated bisphenol A and triethylene glycol; Examples include photosensitive polyesters derived from (2-properidene) malonic acid compounds e+ such as mylidene malonic acid and difunctional glycols.

Furthermore, aromatic azide compounds in which the azide group is bonded to an aromatic ring directly or via a carbonyl group or a sulfonyl group are also used. For example, U.S. Pat. No. 3.0f16,311
Boriasitostyrene, polyvinyl-p-azitobennate, polyvinyl-p-azidobenzal, azidoarylsulfanyl chloride and unsaturated hydrocarbon polymer as described in Japanese Patent Publication No. 45-9G13. The reaction product of Japanese Patent Publication No. 43-21087, 4
No. 4-229, No. 44-22954 and No. 45-24
Examples include polymers having sulfonyl azide and carbonyl azide, as described in No. 915.

Furthermore, a photopolymerizable composition comprising an addition polymerizable unsaturated compound is also used.

The thickness of the photosensitive layer is preferably 0.05 to 10 l, more preferably 0.1 to 2 l.

In addition to the above-mentioned substances, the photosensitive layer composition may contain a surfactant and other commonly used additives and auxiliaries for improving the coating properties of the inorganic filler.

(Silicone Rubber Layer) The silicone rubber used in the silicone rubber layer is a linear organic polysiloxane having the following repeating units, a molecular weight of several thousand to several hundred thousand, and an OH group in the main chain or at the end of the main chain. Preferably, the main component is

-(-5i -0chi.

where n is an integer of 2 or more, R is an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, a vinyl group, an aryl group,
Preferably, it is a silanol group (OH group) and 60% or more of R is a methyl group.

The silanol group (01 (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 silicone rubber useful in the present invention is obtained by a condensation reaction between such a silicone base polymer and a silicone crosslinking agent as listed below.

(1) R-9i+OR') (2) R-Si-(-OAc) (3) R-Si+[N=cR' 2)? Here, R has the same meaning as R explained 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 YE-3085 manufactured by Toshiba Silicone Corporation.

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

(In the formula, 4R has the same meaning as R above, l is an integer of 2 or more, and n is O or an integer of l or more -1-.) In order to obtain silicone rubber by such a crosslinking reaction, , In addition to the above ingredients, tin, zinc cobalt, lead, calcium,
Organic carboxylic acids such as mankan, dibutyltin laurate, tin(II) octoate, cobalt naphthenate, etc. or catalysts such as chloroplatinic acid are added.

In addition, in order to improve the strength of silicone rubber and obtain silicone rubber that can withstand the frictional forces generated during printing operations,
Fillers can also be mixed. Silicone rubber mixed with filler in advance is published as silicone rubber stock or silicone rubber dispersion, and as in the present invention, by coating,
RTV if it is preferred to obtain a silicone rubber membrane.
Alternatively, a dispersion of LTV silicone rubber is preferably used. Such an example is ) -1y Syl Off 23.5RX-
There are silicone rubber dispersions for /<-bar coating such as 257S8237.

In the present invention, in addition to the components listed in L, a small amount of a photosensitizer can be included in the silicone rubber layer.

Preferably, the silicone rubber layer further contains a silane cuff pulling agent to improve adhesion to the photosensitive layer.

Examples of silane coupling agents include the following.

(a) IhHCH20H2HHCCH2CH2CH2
S1(OCH3)3(b) GH2G)1c)I20(
CHz)asi(OCR3h\1 (c) H5(CHz)3si(DCHv)3(d)
CHz-CH5i(DCOCH3)3(f) CHz<
H5i (OC82CH3h(g) HzNC:82CH
2NH(CH2)3si(OCIhh(CHa)(h)
The thickness of the chlorosilane silicone rubber layer is preferably 0.1 to 10 μm, more preferably 0.5 to 2 μm.

Note that in the case of forming a photosensitive silicone rubber layer, a photosensitive layer is not necessary, and as such a photosensitive silicone rubber, γ-methacryloxypropyltrimethoxysilane or monocinnamoyljetoxysilane is added to the terminal OH group of dimethylpolysiloxane. Examples include compounds obtained by dealcoholization condensation of polydiorganosiloxane, compounds obtained by adding a bisazide compound to polydiorganosiloxane, or compounds obtained by reacting acryloyl chloride or P-azidobenzoate.

A light-transmissive film layer is provided on the silicone rubber layer as necessary, and the resin used for the film layer includes polyolefins such as polypropylene, polyethylene, polymethylpentene, and ethylene-butene copolymer. , polystyrene, fluorine resin, polyethylene terephthalate, nylon, polyvinyl alcohol, polycarbonate, polymethyl methacrylate, polyimide polyacrylonitrile, and the like.

Next, a method for manufacturing the plate material of the present invention will be explained.

A composition solution to form a primer layer is applied onto a support using a normal coater such as a reverse roll coater, an air-nay coater, a Meyer bar coater, or a rotary coater such as a Whaler, and then dried to coat the primer layer. form a layer.

Next, a composition solution to form a photosensitive layer is applied in the same manner and dried to form a photosensitive layer.Next, if necessary, an adhesive layer is applied on the photosensitive layer in the same manner and after drying, a silicone rubber solution is applied to the adhesive layer. It is applied in the same way as above, usually 100 to 1
Heat treatment is performed at a temperature of 20° C. for several minutes to fully cure the silicone rubber layer. 8 Then, a light-transmitting film is laminated on the silicone rubber layer.

Next, a method for producing a printing plate using the plate material of the present invention will be explained.

A positive film, which is the manuscript, is vacuum-adhered to the surface of the plate 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.

After exposure, the light-transmissive film is peeled off and developed with a developer to remove only the silicone rubber layer and photosensitive layer or silicone rubber layer in the unexposed areas.

A printing plate in which the recessed image portion is formed can be obtained as described above.

〔Effect of the invention〕

According to the present invention, since the photosensitive layer contains a yellow dye, the sensitivity is not so high, and not only can halation due to reflected light from the support be prevented, but also the sensitivity to image exposure is not so high. To provide a lithographic printing plate material that does not require dampening water and is not a hindrance and has excellent dot reproducibility.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

A primer layer 1 was formed by dispersing a primer liquid 1 having the following composition on an anodized and sodium silicate treated aluminum plate and then coating it. The coating weight after drying is 50I
It was Ig/dm2.

(Primer liquid 1) Copolymer of 2-hydroxyethyl methacrylate/methyl methacrylate (molar ratio 50150)
10g Condensate of 4-diazodiphenylamine and formaldehyde PF6 salt 1g Zinc oxide fine powder (Sakai Chemical Co., Ltd.) 3g Get Yellow 402 (yellow pigment, manufactured by Dainippon Ink Chemical Co., Ltd.) 1.5g Methyl lactate 55g
A primer layer 2 was formed by dispersing and coating a primer liquid 2 having the following composition on a degreased aluminum plate. The coating weight after drying was 50 mg/dm''.

(Primer liquid 2) Copolymer of 2-hydroxyethyl methacrylate/methyl methacrylate (molar ratio 50750)
10 parts by weight 4 parts by weight 4 parts by weight 4 parts by weight 8 parts by weight DA-3
14 (manufactured by Nagase Sangyo) 2 parts by weight DETX (manufactured by Nippon Kayakusho) 0.4 parts by weight Zinc oxide
0 parts by weight Kett Yellow 402 (yellow pigment, manufactured by Dairoki Ink Chemical ■) 0.5 parts by weight Methyl lactate 80 parts by weight
The primer layer was cured by irradiating it with ultraviolet rays.

Next, on these primer layers, a photosensitive layer (thickness: 5 g/drn') having the following composition and a silicone rubber layer (thickness: 2 g/drn') were applied.
0IIg/dm') and laminated with six pots of polypropylene film cover sheets to prepare a plate material sample.

In addition, a plate material sample having no negative or negative dye in the photosensitive layer composition is used as a comparative plate material sample.

(Photosensitive layer composition) PFb salt of condensate of 4-diazodiphenylamine and formaldehyde 80 parts by weight Copolymer of 4-hydroxyphenyl methacrylamide/2-hydroxyethyl methacrylate/methyl methacrylate (50/40/10 in molar ratio) 100 parts Part by weight Victoria Pure Blue BOHAfj Part by weight Yellow color (listed in Table 1) Methyl lactate 4300 parts by weight (silicone rubber M composition) Polydimethylsiloxane with hydroxyl groups at both ends (molecular weight 37
,000) 100 parts by weight Triacetoxysilane 10 parts dibutyltin laurate 0.5 parts by weight Isopar E 1000 parts by weight The obtained plate samples and comparative plate samples were imaged for 40 seconds from a distance of 60 cm using a 4 kW metal halide lamp. After exposure, development was carried out by rubbing the plate surface with absorbent cotton using 5DR-1 (6-fold diluted solution, manufactured by Konica). Note that Ugra chart and Step 7b were used for the images.

Table 1 shows the fine line reproducibility and number of steps of the plate after development.

Table 1

Claims (1)

[Claims] In a lithographic printing plate material that does not require dampening water and has a primer layer, a photosensitive layer and a silicone rubber layer in this order on a support,
A lithographic printing plate material that does not require dampening water, characterized in that the photosensitive layer contains a yellow dye.