JPH03273248A - Dampening-waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To make improvement in the adhesiveness between a base and a photosensitive layer by incorporating a polyurethane resin having film formability and the polycondensation product of a diazonium salt into a primer layer. CONSTITUTION:The polyurethane resin having film formability and the polycondensation product of the diazonium salt are incorporated into the primer layer of the waterless PS plate (dampening-waterless planographic printing plate) formed by providing the primer layer, a photosensitive layer and a silicone rubber layer in this order on a base. The strength of adhesion of the base and the primer layer as well as the primer layer and the photosensitive layer is improved in this way. The sufficient adhesion thereof is sufficiently maintained even if the printing plate is developed after image exposing. The excellent image reproducibility is thus obtd. and the resistance of the resulted planographic printing plate to scratching and printing is improved.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a photosensitive lithographic printing plate that does not require dampening water (hereinafter referred to as waterless P).
The present invention relates to a waterless PS plate that has improved adhesion between the support and the photosensitive layer in a wet state during development processing, and improved printing durability and scratch resistance. .

[Conventional technology]

Various types of waterless PS plates with silicone rubber layers as non-image areas have already been proposed (for example, Japanese Patent Publication No. 44-23042, Japanese Patent Publication No. 46-16044,
JP 54-26923, JP 61-54222, JP 63-265247>.

There are two types of methods for making this type of waterless PS plate. One method is to dissolve the photosensitive layer in the image area m with a developer and remove the silicone rubber layer on top of it to form the image area (Japanese Patent Publication No. 16044/1983). One is a waterless PS made by laminating a photoadhesive photosensitive layer or a photopeelable photosensitive layer and a silicone rubber layer.
This method uses a printing plate to selectively remove only the silicone rubber layer in the tlA area of the image (Japanese Patent Publication No. 54-26923 and Japanese Patent Application Laid-Open No. 56-80046).

In the latter case, taking as an example a waterless PS plate consisting of a photoadhesive photosensitive layer and a silicone rubber layer, it is possible to take advantage of the fact that the photoadhesive photosensitive layer and the silicone rubber layer are firmly photobonded by exposure to light. Then, using a developer that swells the photosensitive layer and/or the silicone rubber layer without substantially dissolving (partially dissolving) the photoadhesive photosensitive layer, the unexposed silicone rubber layer is removed. By selectively peeling and removing, the exposed photosensitive layer is used as an ink receiving area. However, this plate-making method has the following drawbacks. That is,
Since the adhesion between the photosensitive layer and the support is not perfect, a part of the photosensitive layer in the unexposed area peels off from the support, and as a result, the support surface is exposed, and depending on whether the ink receiving area is on the photosensitive layer surface or the support surface, the ink can be Differences in receptivity occur, resulting in uneven ink application, which appears in printed matter, making it impossible to obtain satisfactory printed matter. As an attempt to improve the adhesion between the support and the photosensitive layer, it is known to interpose a primer layer containing an epoxy resin as a component (Japanese Patent Publication No. 61-5
No. 4291). However, although this primer layer has good adhesion to the support, it has the disadvantage that adhesion to the photosensitive layer is largely dependent on the components of the photosensitive layer. For example, when changing the components of the photosensitive layer in an attempt to improve printing durability, scratch resistance, sensitivity, fine line reproducibility, etc., there is another problem in that the adhesion between the primer layer and the photosensitive layer decreases. Regarding the properties, the flexibility of the primer layer as well as the flexibility of the photosensitive layer is greatly affected. In this respect as well, a more flexible ζ primer layer than epoxy resin has been desired. In addition, regarding waterless PS plates using a photoreleasable photosensitive layer, using a rubber component in the primer layer,
It is known that the rubber component is a polyurethane resin (JP-A-6I-163343). However, this method still had the problem of insufficient adhesion to the support.

[Problem to be solved by the invention]

Therefore, an object of the present invention is to provide a waterless PS plate having a novel primer layer with high flexibility and improved adhesion between the support and the photosensitive layer.

[Means to solve the problem]

The object of the present invention is to provide a waterless PS plate in which a primer layer, a photosensitive layer, and a silicone rubber layer are provided in this order on a support, in which the primer layer is made of a polyurethane resin with film-forming ability and a diazonium salt polycondensed biosol. This is achieved by a waterless PS plate characterized by comprising:

Hereinafter, the waterless PS plate of the present invention will be explained in detail.

<Support> The support must be flexible enough to be set in a normal lithographic printing machine, etc., and must be able to withstand the load applied during printing. Typical examples include metal plates such as aluminum, copper, and rope, plastic films or sheets such as polyethylene terephthalate, coated paper, and rubber.

Further, a composite support, a support with rubber elasticity, a support with a rubber elastic layer, and a cylindrical support can also be used.

Preferred supports include aluminum plates and gelatin-subbed plastic films.

The aluminum plate used in the present invention is a plate-shaped body such as pure aluminum or an aluminum alloy containing aluminum as a main component and a trace amount of foreign atoms. These foreign atoms include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of these foreign atoms is at most 10% by weight or less. Aluminum suitable for the present invention is pure aluminum, but
Since completely pure aluminum is difficult to mold due to scouring technology, it is preferable to use aluminum with as low a content of foreign atoms as possible. Further, any aluminum alloy having the above-mentioned content can be said to be a material that can be used in the present invention. As described above, the composition of the aluminum plate applied to the present invention is not specified, and conventionally known and publicly used materials can be used as appropriate. The thickness of the aluminum plate used in the present invention is approximately 0.1-0.5 tm.

If desired, such an aluminum plate is treated with, for example, a surfactant or an alkaline aqueous solution in order to remove rolling oil from the surface.

The aluminum plate thus degreased may be subjected to anodic oxidation treatment and/or hydrophilization treatment, if desired.

Hydrophilic treatment includes alkali metal silicate aqueous solution treatment,
Alternatively, coating of colloidal silica sol is preferred. After the treatment with aqueous alkali metal silicate solution, colloidal silica sol may be applied.

Furthermore, by surface treating the support with various silane coupling agents, the adhesion with the primer layer can be further improved. As a treatment method, it is common to use a silane coupling agent in an aqueous solution of 0.1 to 3% by weight, but there is no problem even at higher concentrations, and the type of silane coupling agent and treatment Depending on the time, etc., sufficient adhesion can be observed even at lower concentrations. The appropriate amount of the silane coupling agent to be applied is 5 .mu./m' to 100 .mu./ml by dry weight.

Primer Layer> The primer layer of the present invention contains a polyurethane resin capable of forming a film and a diazonium salt polycondensation product. By containing the diazonium salt polycondensation product, the adhesive force with the support is improved compared to a primer layer that does not contain the diazonium salt polycondensation product.

Further, the primer layer containing the polyurethane resin and the diazonium salt polycondensation product is preferably cured by exposure to actinic rays or electron beam irradiation after being provided on the support and before providing the photosensitive layer. This makes it possible to improve the adhesion to a support, especially a hydrophilized aluminum substrate or a gelatin-primed plastic film, and to improve solvent resistance.

A preferred diazonium salt polycondensation product used in the present invention is a photosensitive compound containing a structural unit represented by the following format (1).

3 (wherein R1, R2 and R3 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, a substituted aryl group, a sulfonic acid group, a sulfoalkyl group, a carboxyl group or a carboxylic acid ester group, and R is hydrogen atom,
It represents an alkyl group, an aryl group, a substituted aryl group, or a carboxyl group, X represents the counter anion of the diazonium salt, and Y represents +CH, 6→R' -, 10+CH2H2-+-NR'
−-3 +CH2→, NR' −, -3-C') 12c
ONR' -0-R5-0-, -0-, -s- or -
CONR' -, where q is an integer of 0 to 5, r is an integer of 2 to 5, and R4 is hydrogen, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 7 to 12 carbon atoms. Rs represents an aralkyl group having 6 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and Rs represents an arylene group having 6 to 12 carbon atoms. ) Such diazonium salt polycondensation products can be obtained by condensing the corresponding aromatic diazonium salt with an active carbonyl-containing compound (such as formaldehyde) and optionally replacing the anion of the resulting condensation product with another desired anion. It can be obtained by doing. Preferred diazonium salt polycondensation products include, for example, hexafluorophosphates, tetrafluorophosphates, and phosphates of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde. Also, U.S. Patent No. 13,300
．． 309, sulfonates of condensates of p-diazodiphenylamine and formaldehyde (e.g. p-)luenesulfonates, dodecylbenzenesulfonates, 2-methoxy-4-hydroxy-5-
benzoylbenzenesulfonate, etc.), phosphinates (e.g., benzenephosphinate, etc.), hydroxyl-containing compound salts (e.g., 2,4-dihydroxybenzophenone salt, etc.), and organic carboxylates. Among them, JP-A-Sho et al. No. 59-78340, No. 63-26264
Particularly preferred are diazonium salt polycondensation products having a relatively high degree of polymerization, such as those described in No. 3.

Furthermore, 3-methoxy-4-diazo-diphenylamine as shown in JP-A No. 58-27141 is added to 4.4
Mesitylene sulfonate obtained by condensation with '-bis-methoxy-methyl-diphenyl ether is also suitable.

The polyurethane resin with film-forming ability, which is the other component used in the primer layer of the present invention, is a polymer obtained by the addition reaction of polyisocyanate and polyol, and its molecular weight is 5.000 or more on the weight average. 10,000 to 200,000 is suitable, and more preferably 10,000 to 200,000.
000.

Polyisocyanate: toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate,
Hexamethylene diisocyanate, morpholine diisocyanate, diphenylnityl diisocyanate, lysine diisocyanate, isophorone diisocyanate,
0[:N -f-CH2-'rr-N しCONH-f
-CIiK-NCCJ]2, (CH, +r-Nc.

etc. Polyols include polyethylene glycol, polyester diol, polyether ester diol, ethylene glycol, diethylene glycol, neopentyl glycol, polypropylene glycol, polyethylene glycol, triethylene glycol, hexamethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and polyurethane polyol. , unsaturated polyester polyols, etc. These polyisocyanates and polyols may be subjected to an addition reaction by a known method and used as a polymer as is, or in some cases, a polymer may be further polymerized by adding polyamine or water as a crosslinking agent or chain extender. Good too. Alternatively, a polyurethane resin may be used in which an excess of polyisocyanate is added during the reaction of polyisocyanate and polyol, and isocyanate groups remain at the ends. Furthermore, it is a polyurethane resin in which a hydroxyl group is introduced at the terminal by reacting polyurethane with residual incyanate groups at the terminal with jetanolamine or monoethanolamine, or a polyurethane film which is crosslinked by adding a polyisocyanate compound generally known as a crosslinking agent. Good too.

The above diazonium salt polycondensation product and polyurethane resin are dissolved in a suitable solvent, coated on a support, dried, and exposed to actinic rays or irradiated with an electron beam as necessary to dissolve the diazonium salt. The primer layer of the present invention is formed by decomposition. At this time, in order to further improve the adhesion with the support, the primer layer may contain a silane coupling agent, especially an amino group-containing silane coupling agent, an Evoquin group-containing silane coupling agent, or an SH group-containing silane cuff ring. Agents may also be added. Its optimum addition amount is 0.1% to 5% by weight of the solid content of the primer layer.

In addition, dyes and pigments as antihalation agents, TlO□ for whitening, fading dyes and coloring dyes as printing-out agents, other photoacid generators, photoreducing agents, epoxy resins, nitrocellulose resins. , ketone resin, melamine resin, alkyd resin, vinyl acetate copolymer, vinyl chloride copolymer, photopolymerization initiator, (meth)acrylic monomer and prepolymer, silicone surfactant, fluorine surfactant, fluorine surfactant A surface alignment agent may also be added. The amount of the diazonium salt polycondensation compound added in the primer layer is preferably 0.1% to 2% by weight based on the polyurethane resin.
0% by weight, more preferably 0.5% to 10% by weight. The coating amount of the primer layer is 1 to 5 by dry weight.
0 g/m' is appropriate.

<Photosensitive layer> In the present invention, the photosensitive layer used is preferably made of a photopolymerizable photosensitive material, a) a photopolymerizable monomer or oligomer made of an ethylenically unsaturated monomer or oligomer having a boiling point of 100° C. or higher; It contains an initiator, and c) a thermal polymerization inhibitor if necessary.

Each component will be explained below.

B) Photopolymerizable monomers or oligomers Typical examples of photopolymerizable monomers or oligomers include (meth) with a boiling point of 100°C or higher and derived from monovalent alcohols or monovalent amines having 30 or less carbon atoms.
Examples include acrylic esters, (meth)acrylamide, and (meth)acrylic acid esters or (meth)acrylamide with a boiling point of 100° C. or higher derived from polyhydric alcohols or polyhydric amines having 80 or less carbon atoms.

Next, representative monomers useful in the present invention are listed.

Some of these can also be used as raw materials for oligomers useful in the present invention.

(E1) (Meth)acrylic acid esters of the following alcohols methanol, ethanol, propatool, pentanol, cyclohexanol, octatool, undecanonopenorbornyl alcohol, polymethylene glycol,
Ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glyceronope trimethylolmethane, pentaerythritol (E1i) <meth>acrylic acid glycidyl ester and adducts such as hydrogen halides, amines, carboxylic acids, etc.
Ring-opened polymers of glycidyl groups, etc., for example, (meth)acrylamide derivatives (meth)acrylamide, N-methylol (meth>acrylamide, N-methoxymethyl (meth) ) acrylamide, methylene bis(meth)acrylamide, hexamethylene bis(meth)acrylamide, diacetone acrylamide, hydroxymethyldiacetone acrylamide.

The most useful monomers that can be used in the photopolymerizable photosensitive material in the present invention include the following.

Ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, Syhentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylidero) photopolymerization initiator Typical examples of photopolymerization initiators that can be used in the present invention include the following.

(Rho i) Benzophenone derivatives, such as benzophenone, Michler's ketone, xanthone, anthrone, thioxanthone, acridone, 2-chloroacridone, 2
- Chloro-N-n-butyl acridone, etc. (rho-h) Benzoin derivatives, such as benzoin, benzoin methyl ether, benzoin ethyl ether, etc. (rho-1ii) Quinones, such as p-benzoquinone, β-naphthoquinone, β-methylanthraquinone (Rho IV) Sulfur compounds, such as dibenzyl disulfide, di-n-butyl disulfide, etc. (Rho ■) Azo or diazo compounds, such as 2-azo-bis-isobutyronitrile, 1-azo-bis-1 −
Cyclohexanecarbonitrile, p-diazobenzylethylaniline, Congo red, etc. (low vi) halogen compounds, such as carbon tetrabromide, silver bromide, α-chloromethylnaphthalene, trihalomethyl-
3-)! J Azine compounds, etc. (Rho West) Peroxides, such as benzoyl peroxide, etc. (Rho VI) Uranyl salts, such as uranyl nitrate C) Thermal polymerization inhibitors As thermal polymerization inhibitors, hydroquinone derivatives, phenol derivatives, nitro-substituted Benzene, tertiary amines, phenothiazine derivatives, etc. are used.

According to a preferred embodiment of the invention, a solvent-soluble polyurethane resin capable of forming a film is used as the binder of the photopolymerizable photosensitive material. It is preferred that the second polyurethane resin has the same or similar structural units as that used in the primer layer. This is because intermolecular hydrogen bonding due to urethane bonds and urea bonds can be expected between the primer layer and the photosensitive layer, and it is thought that the adhesion between the layers will become stronger. In particular, when the same compound is used for the primer layer and the photosensitive layer, the adhesive strength of the photosensitive layer ξ primer layer is expected to be further improved.

Preferred polyurethane resins used as binders in the photosensitive layer include those derived from polyester polyols, polyether polyols, polyalcohols and polyisocyanates, and urea resins obtained by substituting part of the above polyols with polyamines to extend the chain. It is a polyurethane resin containing bonds.

Examples of polyester polyols include condensed polyester polyols, lactone polyester polyols, and polycarbonate diols. Condensation type polyester polyol is made of adipic acid and ethylene glycol,
Diethylene glycol, propylene glycol, 1.4
- It is obtained by dehydration condensation with butanediol, neopentyl glycol, trimethylolfuropane, 1,6-hexanediol, etc.

The lactone-based polyester polyol is obtained, for example, by open polymerization of ε-caprolactone and a diol. Polycarbonate diol is, for example, 1.6-
It is obtained by the reaction of hexanediol and ethylene carbonate.

A polyether polyol can be obtained by reacting an initiator having active hydrogen with an alkylene oxide, and propylene oxide or ethylene oxide can be used as the alkylene oxide.

Examples of polyalcohols include ethylene glycone diethylene glycol, propylene glyconope 1,4-butanediol, neopentyl glycol, trimethylolpropane, and 1,6-hexanediol.

In addition, as polyisocyanates, 1,5-naphthalene diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, inphorone diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, lysine diisocyanate, tetramethyl xylene diisocyanate, lysine ester triisocyanate, 1, Examples include 6.11-undecane triisocyanate, 1.8-diisonoanate-4-incyanate methyloctane, 1.3.6-hexamethylene triisocyanate, and bicyclohebutane triisocyanate.

Examples of polyamines include diphenylmethanediamino Il conductors, m-phenylenediamine derivatives, ethylenediamine, 1,4-diaminobutane, 116-noamitsuhexane, and inphoronediamine.

The amount of these polyurethane resins added is suitably 10 to 90% by weight based on the total dry weight of the photosensitive layer.

In addition to the above-mentioned photopolymerizable photosensitive materials, other photosensitive materials that can be used include those whose solubility in a developing solution changes depending on exposure, or whose adhesive strength with the upper silicone rubber layer changes. . Examples of such materials include photosensitive materials of photodimerization type, photocurable diazo resin photosensitive materials, and photosensitive materials comprising 0-quinonediazide compounds, which are described in JP-A No. 62-50760.

Additives may be added to the photosensitive layer depending on the purpose. For example, as a stabilizer, hydroquinone, p-methoxyphenol, di-t-butyl-p-talezonopevilrogallol, t-butylcatechol, benzoquinone, 4.4'-
Thiobis(3-methyl-6-t-butylphenol),
Examples include 2'-methylenebis(4-methyl-6-t-butylphenol) and 2-mercaptobenzimidazole. Further, dyes or pigments may be added for the purpose of coloring the photosensitive layer, and pH indicators, leuco dyes, and fading dyes may be added as print-out agents. Further, a small amount of silicone compounds such as polydimethylsiloxane, methylstyrene-modified polydimethylsiloxane, olefin-modified polydimethylsiloxane, silane coupling agent, silicone diacrylate, silicone dimethacrylate, etc. may be added to the photosensitive layer. Furthermore, a fluorine-based surfactant or a fluorine-based surface alignment agent may be added to improve coating suitability. Furthermore, in order to strengthen the adhesion with the silicone rubber layer if necessary, silica powder or hydrophobic silica powder whose surface has been treated with a (meth)acryloyl group or allyl group-containing silane coupling agent is added to the entire photosensitive layer composition. It may be added in a layer of 50% by weight or less. As other additives, epoxy resins, ketone resins, melamine resins, alkyd resins, vinyl acetate copolymers, vinyl chloride copolymers, and diazonium salt polycondensates may be added.

The photosensitive layer composition as described above includes 2-methoxyethanol, 2
- Dissolved in a suitable solvent such as methoxyethyl acetate, methyl lactate, ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methanol, ethanol, methyl ethyl ketone, water, etc. alone or in a mixed solvent of an appropriate combination thereof. Then, the primer layer is coated on the primer layer to a coating weight of about 0.1 to 10 g/m', more preferably 0.5 to 5 g/m' after drying, and dried.

Silicone Rubber Layer> The silicone rubber layer preferably used in the present invention is a linear or partially crosslinked polydiorganosiloxane, and has the following repeating units.

-F-31-Ox Here, R represents an alkyl group, an aryl group, an alkenyl group, or a combination of these monovalent groups, and these include a halogen atom, an amino group, a hydroxy group, an alkoxy group, an aryloxy group, It may have a functional group such as a (meth)acryloxy group or a thiol group. In addition, the silicone rubber may contain fine powders of inorganic substances such as silica, calcium carbonate, and titanium oxide, adhesion aids such as the silane coupling agents, titanate coupling agents, and aluminum coupling agents, and light. A polymerization initiator may also be added.

High molecular weight polymer (
Polysiloxane with a molecular weight of several thousand to several hundred thousand and has a functional group at the end is used as a raw material for silicone rubber.
This is crosslinked and cured in the following manner to obtain a silicone rubber layer. Specifically, a silane crosslinking agent represented by the following general formula is mixed into the polysiloxane having a hydroxyl group at both ends or only at one end, and if necessary, an organometallic compound such as an organic A catalyst such as a tin compound, an inorganic acid, or an amine is added, and the polysiloxane and the silane crosslinking agent are heated or condensed and cured at room temperature.

R, SiX, -.

Here, n is an integer of 1 to 3, R is the same substituent as R shown above, and X represents a substituent such as -DH1-〇R2-e. Here, R2 and R3 have the same meaning as R described above, and R2 and R3 may be the same or different. Moreover, Ac represents an acetyl group.

Other organopolysiloxanes with hydroxyl groups at the ends,
The hydrogen polysiloxane crosslinking agent and, if necessary, the above-mentioned silane crosslinking agent are condensed and cured.

In addition, an addition-type silicone rubber layer crosslinked by an addition reaction between a 3S r H group and a -CH=CH- group is also useful. The addition-type silicone rubber layer is relatively unaffected by humidity during curing, and can be crosslinked at high speed.
It has the advantage that a silicone rubber layer with constant physical properties can be easily obtained.

The addition type silicone rubber layer used here is obtained by the reaction of a polyvalent hydrogen organopolysiloxane and a polysiloxane compound having two or more -CH=CH-116 groups in one molecule, and is preferably as follows: Components: (1) 100 parts by weight of an organopolysiloxane having at least two alkenyl groups (more preferably vinyl groups) bonded to a silicon atom in one molecule (2) At least in one molecule; S r H Orcanohydrogenpolysiloxane with two bonds 0.1
~1000 parts by weight (3) Addition catalyst A composition consisting of 0.00001 to 10 parts by weight is cured and crosslinked. The alkenyl group of component (1) may be located either at the end or in the middle of the molecular chain, and preferred organic groups other than the alkenyl group are:
A substituted or unsubstituted alkyl group or aryl group.

Component (1) may have a trace amount of hydroxyl group. Ingredients (2
) reacts with component (1) to form a silicone rubber layer, but also plays the role of imparting adhesiveness to the photosensitive layer. The hydrogen group in component (2) may be located either at the end or in the middle of the molecular chain, and the organic groups other than hydrogen are selected from those similar to component (1).

In order to improve ink repellency, it is preferable that 60% or more of the organic groups in component (1) and component (2) be methyl groups.The molecular structures of component (1) and component (2) are It may be cylindrical, cyclic or branched, and preferably the molecular weight of at least one of them exceeds 1.000 from the viewpoint of rubber physical properties, and furthermore, the molecular weight of component (1) is 1.000.
It is preferable that it exceeds.

Examples of component (1)≧ include α,ω-divinylborodimethylsiloxane, (methylvinylsiloxane)(dimethylsiloxane) copolymer having methyl groups at both ends, and component (2), which has both terminal methyl groups. Examples include polydimethylsiloxane with terminal hydrogen groups, α, ω-dimethylpolymethylhydrodienesiloxane, (methylhydrodienesiloxane) (dimethylsiloxane) copolymer with methyl groups at both terminals, cyclic, polymethylhydrodienesiloxane, etc. .

The addition catalyst of component [3) is arbitrarily selected from known ones, but platinum-based compounds are particularly desirable, and examples thereof include simple platinum, platinum chloride, chloroplatinic acid, and olefin-coordinated platinum. For the purpose of controlling the curing rate of these compositions, vinyl group-containing organopolysiloxanes such as tetracyclo(methylvinyl)siloxane, carbon-carbon triple-containing alkonopacetones, methyl ethyl ketone,
It is also possible to add crosslinking inhibitors such as methanol, ethanol, propylene glycol monomethyl ether.

In these compositions, an addition reaction occurs and curing begins when the three components are mixed, but the curing rate has a characteristic that 5) the curing rate decreases rapidly as the reaction temperature increases. Therefore, in order to lengthen the pot life of the composition until it becomes a rubber and shorten the curing time on the photosensitive layer, the curing conditions for the composition are set at a temperature within a range that does not change the characteristics of the support and the photosensitive layer. , and kept at high temperature until completely cured.
This is preferable in terms of stability of adhesive strength with the photosensitive layer.

In addition to the composition of S, known adhesion promoters such as alkenyltrialkoxysilanes may be added, or organopolysiloxanes containing hydroxyl groups, which are the compositions of the condensed silicone rubber layer, silanes containing hydrolyzable functional groups ( or siloxane) may be optionally added, and it is also optional to add a known filler such as silica for the purpose of improving rubber strength.

The silicone rubber layer in the present invention serves as a printing ink repellent layer, and if the thickness is small, the ink repellency decreases,
If the thickness is large due to problems such as easy scratches, the developability will be poor, so the thickness is 0.5 μm.
5 μm is suitable.

In the waterless PS plate described here, it is optional to coat various silicone rubber layers on top of the silicone rubber layer. For the purpose of preventing poisoning of the catalyst in the rubber composition, an adhesive layer may optionally be provided between the photosensitive layer and the silicone rubber layer. To protect the surface of the silicone rubber layer, a transparent film such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, cellophane, etc. is laminated on the silicone rubber layer, or a polymer coating is applied. It may be applied. Furthermore, the surface of the transparent film provided on the silicone rubber layer on the side opposite to the silicone rubber layer can be made matte.
Particularly preferred in this case are those described in European Patent No. 130222B.

After the waterless PS plate according to the present invention is exposed through the original image, it is developed with a developer that can dissolve or swell a part or all of the photosensitive layer in the image frg area, or a developer that can swell and swell the silicone rubber layer. be done. In this case, there are cases where part of the photosensitive layer in the image area and the silicone rubber layer thereon are removed, and cases where only the silicone rubber layer in the image area is removed, and this can be controlled by the strength of the developer. can.

The developer used in the present invention is waterless PS
Known plate developers can be used. For example, aliphatic hydrocarbons: hexane, heptane, “Isopar E
, H, G" (trade name of aliphatic hydrocarbons manufactured by Esso Chemical ■) or gasoline, kerosene, etc.), aromatic hydrocarbons S (toluene, xylene, etc.), or halogenated hydrocarbons (triclene, etc.) below. It is possible to use one with a polar solvent added to it.

Alcohols (methanol, ethanol, propatool, benzyl alcohol, ethylene glycol monophenyl ether, 2-methoxyethanol, 2-ethoxyethanol, carpitol monoethyl ether, carpitol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl Ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, propylene glycol, polypropylene glycol (triethylene glycol, tetraethylene glycol), ketones (acetone, methyl ethyl ketone), esters (ethyl acetate, lactic acid) Methyl, ethyl lactate, butyl lactate,
propylene glycol monomethyl ether acetate,
Carpitol acetate, dimethyl phthalate, diethyl phthalate) A particularly preferred developer contains 0.1 to 1001i weight % of a propylene oxide derivative having an average molecular weight of 100 to 1.000 as described in Japanese Patent Publication No. 63-21890.
Containing ethylene glycol monoalkyl ether or diethylene glycol monoalkyl ether as described in VF Application No. 1-139558 and No. 2-27859 (herein, the alkyl group is 5 to 5 carbon atoms). 8)).

During development, the silicone rubber layer in the image area is removed by, for example, rubbing the printing plate with a developing pad containing a developer as described above, and the photosensitive layer is exposed, which becomes an ink receiving area.

Further, according to the method described in Japanese Patent Publication No. 63-33140, a part or all of the photosensitive layer in the image area is eluted using a processing liquid capable of dissolving at least a part of the photosensitive layer in the image area, and then the silicone rubber A developing method in which the silicone rubber layer in the image area is peeled off by rubbing the printing plate in the presence of 5) water or a solvent mainly composed of water, which does not have the effect of swelling the layer, can also be applied. In this case, JP-A-63-163357
It is preferable to develop the film by the method described in the above issue or by an automatic processor using that method.

In order to confirm the image forming properties of the printing plate obtained in this way, the exposed image area (photosensitive layer) is stained with a staining solution and the plate is inspected. By impregnating a soft pad with the staining solution and lightly rubbing the image area, only the exposed image area of the photosensitive layer is dyed, thereby confirming that the development has been sufficiently performed to the highlight area. As a dyeing solution, one or more types selected from water-soluble disperse dyes, acidic dyes, and basic dyes are dissolved in a solution of water, alcohols, ketones, ethers, etc. alone or in a mixture of two or more types. Alternatively, a dispersed version is used. To improve stainability,
It is also effective to add carboxylic acids, amines, surfactants, dyeing aids, etc.

〔Effect of the invention〕

In the waterless PS plate of the present invention, the adhesion strength between the support and the primer layer, and between the primer layer and the photosensitive layer is dramatically improved, and even after image exposure and development, the above adhesion is sufficiently maintained. In addition to showing excellent surface image reproducibility, the obtained lithographic printing plate has excellent scratch resistance and printing durability.

<Examples> The present invention will be further explained below with reference to Examples, but the present invention is not limited to these Examples.

Note that % indicates weight % unless otherwise specified.

Synthesis Example 1 Commercially available polyester polyol (○D-X-105: condensate of molecular weight 2.000 consisting of adipic acid/ethylene glycol/butanediol: Dainippon Ink & Chemicals ■
) 40.06 parts by weight, 1° 4-butanediol 6.5
0 parts by weight, inphorone diisocyanate) 23.34 parts by weight were dissolved in 46.6 parts by weight of dimethylacetamide,
The reaction was carried out at 90° C. for 6 hours to obtain a 60% solution of polyurethane resin liquid (1).

Synthesis Example 2 Commercially available polyester polyol (OD-X-105: manufactured by Dainippon Ink & Chemicals) 40.06 parts by weight, 1,4-
3.25 parts by weight of butanediol, 23.34 parts by weight of isophorone diisocyanate and 45 parts by weight of dimethylacetamide.
It was dissolved in 57 parts by weight and reacted at 90°C for 6 hours. Then more! ! Inphorondiamine as an agent 1.
71 parts by weight was added and reacted at 90° C. for 2 hours to obtain a 60% solution of polyurethane resin liquid (It).

Example 1 0,24m treated with silicate after degreasing in the usual manner
A primer solution having the following composition was applied to a smooth aluminum plate having a thickness of m and dried at 100° C. for 2 minutes to obtain a primer layer with a dry weight of 4 g/m′.

20 parts by weight of propylene glycol monomethyl ether 0.01 part by weight of fluorine surfactant Then FT26IV UDNS ULTR manufactured by Nuark
A-PLUSFLIPT [lP PLATE MAKE
The diazonium salt was completely photodecomposed by 100 count exposure using Rii Koki.

On this exposed primer layer, a photosensitive solution made of the following photopolymerizable photosensitive material was applied to a dry weight of 3 g/m'' and dried at 100° C. for 1 minute.

Ethyl Michler's ketone 0.2 parts by weight Dimethylthioxanthone 0.1 parts by weight iO2 Methyl ethyl ketone 0.12 parts by weight 30 parts by weight Fluorine surfactant 0.01 parts by weight Methyl ethyl ketone 10 parts by weight Next, on the above photosensitive layer, The dry weight of the following silicone rubber composition liquid is 2
．． The silicone rubber layer was coated at 0 g/m'' and dried at 140° C. for 2 minutes.

C) 13 CH, C) 13 Jin H1
CHz SiO+SiO narrow-←510 +T
-r-3I CH3CN, [l(, HCH3 1 weight ole7yne-chloroplatinic acid catalyst solution 0.2 parts by weight Inhibitor 0.15 parts by weight Thickness was applied to the surface of the silicone rubber layer obtained as above. A biaxially oriented polypropylene film with a diameter of 9 μm and one side matted was laminated so that the unmatted side was in contact with the silicone rubber layer to obtain a waterless 25th plate.

This 25th plate was overlaid with a 2001 [/inch] halftone dot positive film, exposed for 30 counts in a vacuum using the above-mentioned Nuark exposure machine, and then the laminated film was peeled off and a 40°C film of tripropylene glycol was applied. It was immersed in the liquid for 1 minute. Thereafter, the silicone rubber layer in the unexposed areas was removed by rubbing with a developing pad in water to obtain a lithographic printing plate that did not require dampening water and had excellent halftone dot reproducibility. This printing plate had excellent adhesion between the photosensitive layer and the primer layer, and between the primer layer and the support, and neither the non-image area nor the image area peeled off from the support during development. In the case where the diazonium salt polycondensation product was not added to the primer layer, the image area peeled off from the support.

Example 2 A primer liquid having the following composition was used instead of the primer liquid of Example 1, and dried at 100°C for 2 minutes to obtain a primer layer with a dry weight of 6 g/m''.

Developer\Tin□ 0.12 parts by weight Methyl ethyl ketone 30 parts by weight Propylene glycol 20 parts by weight Monomethyl ether Fluorine surfactant 0.01 parts by weight Other than that, a waterless PS plate was obtained in the same manner as in Plan 1.

After developing the image on this printing plate in the same manner as in Example 1, the laminate film was peeled off, immersed in the following developer for 1 minute, and then rubbed with a developing pad to remove the uncolored silicone rubber layer. A lithographic printing plate which does not require dampening water and has excellent halftone dot reproducibility was obtained. This printing plate also had good adhesion between the support and the primer layer, and was unlikely to peel off during development.

Example 3 Example 1 The following primer solution was applied on a silicate-treated 0.24M nium plate made of thick aluminum cloth and used in a 14 m' ply.The primer solution was heated at 0°C for 2 minutes to give a dry weight of 5 g/mer layer. has been established.

i02 Fluorine surfactant 0.12 parts by weight 0.01 parts by weight On the aluminum support coated with the above primer layer,
A photosensitive solution made of the following photopolymerizable photosensitive material was added to the dry weight of 3
g/m'' and dried at 100°C for 1 minute.

Fluorine surfactant Methyl ethyl ketone Ethylene glycol methyl ether 0.01 parts by weight 15 parts by weight 5 parts by weight Next, apply the following silicone rubber composition onto the photosensitive layer to a dry weight of 2.0 g/m'. Apply as shown, 120
It was dried for 2 minutes at ℃ to obtain a silicone rubber layer.

0.1 parts by weight of tin catalyst 0.2 parts by weight of ethyl Michael's ketone 2-chlorothioxanthone 0.05 parts by weight A waterless PS plate was obtained by laminating a matt double-glazed stretched polypropylene film.

This water fL L P S plate was subjected to image exposure and development in the same manner as in Example 2 to obtain a lithographic printing plate that did not require dampening water and had excellent halftone dot reproducibility.

Example 4 The primer liquid of Example 1 was applied on the silicate-treated aluminum plate of 0.24 mm thickness used in Example 1,
It was dried at 100° C. for 2 minutes to obtain a primer layer with a dry weight of 4 g/m′. After that, Ei (Energy 5ci
15 using an electron irradiation device manufactured by ence Inc.
Irradiate the 'l@rad electron beam with an accelerating voltage of 0KV,
The diazonium salt was completely decomposed.

A PS plate without water was obtained in the same manner as in the other plan side 1. As a result of imagewise exposure and development of the waterless PS plate in the same manner as in Example 1, a lithographic printing plate that did not require dampening water and had excellent halftone dot reproducibility was obtained.

This printing plate also had good adhesion between the support and the primer layer, and did not peel off during development.

Claims (2)

[Claims] (1) In a photosensitive lithographic printing plate that does not require dampening water, in which a primer layer, a photosensitive layer, and a silicone rubber layer are provided in this order on a support, the primer layer is a polycondensation product of a polyurethane resin with film-forming ability and a diazonium salt. A photosensitive lithographic printing plate that does not require dampening water. (2) Claim (1) characterized in that the primer layer containing a polyurethane resin and a diazonium salt polycondensation product is cured by exposure to actinic rays or electron irradiation.
) Photosensitive lithographic printing plate that does not require dampening water.