JPH01235955A - Waterless planographic printing master plate - Google Patents

Abstract

PURPOSE:To obtain the title plate which has the excellent image reproducibility and a less change of sensitivity and to make possible to develop the master plate with a developer which contains water or an aqueous alkaline solution as a main component by incorporating a photosensitive polymer compd. which has a specified group and one of carboxylic group or salt thereof in the side chain, and is soluble to the water and the aqueous alkaline solution, in the photosensitive layer. CONSTITUTION:The photosensitive polymer compd. which has at least two of groups shown by formula I or II in the side chain of the polymer, and at least one of carboxylic acid group or its salt and is soluble to the water or the aqueous alkaline solution, is incorporated in the photosensitive layer. In formulas I and II, A is aryl, a substd. arl, furyl or thienyl group, B is hydroxyl, alkoxyl, aryl, a substd. aryl or alkyl group, X is H or halogen atom., or CN group, etc., Y is H or halogen atom. or CN, phenyl or alkyl group, (n) is an integer of 0 or 1. Thus, the master plate which has the less change of the sensitivity and the good image reproducibility and makes possible to develop with a relatively mild developer, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a waterless lithographic printing original plate that can be printed without using dampening water.

[Prior art and issues to be solved]

Several inventions have been made in the past regarding planographic printing original plates that can be printed without using dampening water.

For example, Special Publication No. 44-23042, Special Publication No. 46-1
6044, Special Publication No. 17081, Special Publication No. 17081, Special Publication No. 54-
No. 26923, JP-A-56-80064, JP-A-55
There is No.-22781. Among these, types using a photopolymerizable photosensitive layer as disclosed in Japanese Patent Publication No. 54-26923, Japanese Patent Publication No. 56-23150, etc., and Japanese Patent Publication No. 55-22781 A type using a photodimerizable photosensitive layer disclosed in 2006 is common.

In types that use a photopolymerizable photosensitive layer, photoadhesion occurs between the silicone rubber layer and the photosensitive layer upon exposure to light, so an adhesion aid (adhesive agent) that provides adhesion to the photosensitive layer is usually added to the silicone rubber layer.
There is no need to add silane coupling agents, etc. When such photoadhesion is used, by developing with a solvent that swells the silicone rubber layer, only the unexposed portions of the silicone rubber layer can be removed without eluting the underlying photopolymerizable layer. However, since an image forming method essentially using photoadhesion is used, the halftone dot reproducibility of a portion of the shadow where the amount of light is insufficient is not necessarily sufficient. In order to solve this problem, an adhesion aid such as an aminosilane coupling agent is added to the silicone rubber layer, so that the silicone rubber layer is firmly adhered to the photosensitive layer from the beginning, and a developer solution is applied to dissolve the photosensitive layer. There is a method of forming an image by eluting the photopolymerized layer below the unexposed area using the photopolymerization layer.

When such a method is adopted, the halftone dot reproducibility in the shadow part improves, but on the other hand, the halftone dot reproducibility in the highlight part deteriorates as the photosensitive layer and silicone layer bond further over time, resulting in deterioration of developability. Sometimes it became defective. When this local polymerization type photosensitive layer is used, it has the disadvantage that the sensitivity varies greatly depending on the temperature at the time of exposure or the time left after exposure until development. becomes.

On the other hand, unlike the photopolymerizable photosensitive layer, the type that uses a photodimerizable photosensitive layer cannot obtain sufficient photoadhesion, so a silane coupling agent or the like is added as an adhesion aid to the silicone rubber layer in advance. It is necessary to maintain strong adhesion between the layer and the photosensitive layer. In this case, unlike a photopolymerizable photosensitive layer, there is no disadvantage that the sensitivity fluctuates greatly depending on the temperature during exposure or the standing time from exposure to development. Therefore, as with the photopolymerizable photosensitive layer, it is recognized that the halftone dot reproducibility in highlight areas deteriorates over time.

[Object of the present invention]

Therefore, an object of the present invention is to provide a waterless lithographic printing original plate which has excellent image reproducibility, whose softness does not vary depending on the temperature during exposure, and which can be processed with a developer mainly containing water or alkaline water. That's true.

[Means to solve the problem]

In a waterless lithographic printing original plate in which a photosensitive layer and a silicone rubber layer are laminated in this order on a substrate, the present inventor has developed a silicone rubber crosslinked by an addition reaction between an SiH group and a -CH-CH- group as a silicone rubber layer. By using a photosensitive polymer compound having a photodimerizable unsaturated double bond group and a carboxylic acid group or a salt thereof as a photosensitive layer, processing with a developer mainly consisting of water or alkaline water is possible. The inventors have discovered that it is possible to obtain a waterless lithographic printing original plate that is possible, has little sensitivity variation depending on the environment during exposure, and has excellent image reproducibility, and the present invention was made based on this knowledge.

That is, the present invention relates to a substrate, a photosensitive layer provided on the substrate, and a silicone rubber provided on the photosensitive layer, which is crosslinked by an addition reaction between SiH groups and -CH=CH- groups. In a waterless lithographic printing original plate consisting of a layer, the photosensitive layer has at least two of the following general formula (I) or (■) in the side chain: (However, A neararyl group, substituted aryl group,
Furyl group or thienyl group B: hydroxyl group, alkoxy group, aryl group, substituted aryl group or alkyl group , a phenyl group or a haalkyl group (n: an integer of 0 or 1); and at least one carboxylic acid group or a salt thereof in the side chain, and is soluble in water or alkaline water. The present invention relates to a waterless lithographic printing original plate characterized in that it is made of a polymeric compound.

The present invention will be explained in detail below.

The waterless lithographic printing original plate of the present invention must be flexible enough to be set in a normal printing machine and must be able to withstand the load applied during printing. Therefore, typical substrates include coated paper, metal plates, plastic films such as polyethylene terecrate, rubber, and composite substrates thereof. The surface of these substrates may be further coated with a primer layer or the like for antihalation and other purposes, and may be used as a support.

As the primer layer, various photosensitive polymers described in JP-A No. 60-229031 are used before laminating the photosensitive layer! This exposed and hardened product, patent application No. 62-507
A heat-cured epoxy resin disclosed in Japanese Patent Application No. 61-281194 and a hardened gelatin layer disclosed in Japanese Patent Application No. 61-281194 are used. Other materials with hardened zein layers are also effective. Furthermore, additives such as dyes, print-out agents, polymerizable monomers as photoadhesives, and photopolymerization initiators can be added to these primer layers for antihalation and other purposes. Generally, the coating thickness of the primer layer is between 2g/m' and 1.0g/m'.
It is m'.

Water or alkali having at least two groups represented by the general formula (T) or (I[>) in the side chain and at least one carboxylic acid group or a salt thereof in the side chain used in the photosensitive layer of the present invention. Examples of water-soluble photosensitive polymer compounds include acrylic acid containing a group represented by the general formula (1) or (II) as described in Japanese Patent Application No. 18573/1983. There are copolymers of esters, meccrylic acid esters, or vinyl ether compounds and α,β-unsaturated carboxylic acids, and copolymers copolymerized with other addition-polymerizable vinyl monomers as necessary.

Examples of acrylic acid ester methacrylic ester or vinyl ether compounds containing a group represented by formula (i) or (II) include Japanese Patent Publication No. 49-28122, British Patent No. 1,363,214, and Japanese Patent Application Laid-open No. 47734794. ,
Japanese Patent Publication No. 50-11283, Japanese Patent Publication No. 51-481, Japanese Patent Publication No. 49-36794, Japanese Patent Publication No. 56-52923,
JP 55-31452, JP 57-56485, JP 50-24384, JP 49-10397
No. 5, Special Publication No. 56-37244, Special Publication No. 55-449
No. 30, Special Publication No. 13776, British Patent No. 1, 3
No. 14,689, Special Publication No. 49-14352, Special Publication No. 5
Examples include those described in the specifications of Japanese Patent Publication No. 0-24621, Japanese Patent Publication No. 57-28488, Japanese Patent Application Publication No. 50-22850, and Japanese Patent Application Publication No. 46-3147.

Other photosensitive polymer compounds that are soluble or swellable in alkaline water include acrylic esters or meccrylic esters containing a group represented by formula (I) or (II) and a carboxyl group, such as Japanese Patent Publication No. Sho 51- 482, a homopolymer of the monomer described in the specification of JP-A-49-36794, or a copolymer with other monomers; a group represented by formula (1) or (, I[); Products in which a compound having a hydroxyl group or an amino group is added to a copolymer having an acid anhydride group, such as those described in US Patent No. 2.
No. 816.091, U.S. Patent No. 2.824.087;
U.S. Patent No. 2.811.509, U.S. Patent No. 2.75
Adducts with maleic anhydride copolymers as described in the specification of No. 1.373; adducts with polymeric compounds having hydroxyl groups; After reacting with a polymer compound having a hydroxyl group or an amino group, it is saponified with an alkali to end with a carboxyl group: strained, polyvinyl alcohol;
Formula (1) or (II) is obtained by reacting a compound having an NH2 group with some carboxyl groups of an acrylic acid or methacrylic acid copolymer; ) or (II) and a compound having -NC○, -CQCff or a cyclic acid anhydride group; a polyester polymer consisting of dimethylolpropionic acid; a polyester polymer consisting of 1 mol of dimethylolpropionic acid; Examples include polyurethane obtained by reacting glycol having a terminal hydroxyl group with diisocyanate; polyurethane obtained by reacting a diisocyanate with a compound having two hydroxyl groups obtained by reacting an epoxy resin with cinnamic acid, and a diol consisting of dimethylolpropionic acid. I can do it. In addition, a polymer compound that does not have a carboxylic acid group in its side chain but contains at least two or more groups represented by the general formula (1) or (n) in its side chain has a partially activated mercapto group. Photosensitive polymer compounds obtained by adding carboxylic acids are also useful.

In order to make the photosensitive polymer compound having a carboxylic acid in its side chain water-soluble, it may be converted into a salt form by neutralizing it with hydroxide, potassium hydroxide, or an amine.

The preferred molecular weight range of these photosensitive polymer compounds is 2.
000 to 500.000. More preferably 10.
000 to 150,000. Further, the acid value of these photosensitive polymers is preferably 20 to 200, and an acid value of 20 or less is not preferable because the solubility in alkaline water decreases.

In the present invention, a photosensitizer may be added to the photosensitive layer if necessary. Examples of such sensitizers include benzophenone derivatives, benzanthrone derivatives, quinones, aromatic nitro compounds, naphthothiazoline derivatives, benzothiazoline derivatives, thioxanthones, ketocoumarin compounds, naphthofuranone compounds, biryllium salts, thiapyrylium salts, etc. I can do it. Specifically, Michler's ketone, N
, N'-diethylamine benzophenone, benzanthrone, (3-methyl-1,3-diacer1,9-benz)anthrone picramide, 5-nitroacenaphthene, 2
-Chlorthioxanthone, 2-isoprobylthioxanthone, dimethylthioxanthone, methylthioxanthone-1-ethylcarboxylate, 2-nitrofluorene, 2-dibenzoylmethylene-3-methylnaphthothiazoline, 3,3-carbonyl-bis(7-dini tylaminocoumarin), 2.4.6-) liphenylthiapyrylium perchlorate, and the like. The appropriate amount of these sensitizers added is 1 to 20% by weight, more preferably 3 to 10% by weight of the total photosensitive layer composition.

In addition to the above, it is preferable to further add a thermal polymerization inhibitor to the photosensitive layer, such as hydroquinone, p-methoxyphenol, di-t-butyl-p-crezonopepyrogallol, t-butylcatechol, benzoquinone, 4
．． 4'-thiobis(3-methyl-6-t-butylphenol), 2,2'-methylenebis(4-methyl-6-t
-butylphenol), 2-mercaptobenzimidazole, and the like are useful, and in some cases, dyes or pigments, and pH indicators as printing agents may be added for the purpose of coloring the photosensitive layer.

The thickness of the photosensitive layer as explained above is preferably as thin as possible in the case of a plate-making method in which the photosensitive layer and silicone rubber layer in the image area are removed in the development step after image exposure; is desirably selected from the range of 5μ or less, particularly from 0.1 to 1μ.

The silicone rubber layer in the present invention serves as a printing ink repellent layer, and if the thickness is small, there are problems such as a decrease in ink repellency and easy scratching, and if the thickness is large, developability is poor. Therefore, the thickness is 0.5
It is preferable that it is from μ to 5μ.

The silicone rubber layer in the present invention is formed by crosslinking by an addition reaction between SiH groups and -CH=CH- groups, and the resulting silicone rubber layer has better ink repulsion than a condensation type. It has the feature of excellent properties. In addition, it has excellent adhesion with the photosensitive layer used in the present invention, and in contrast to the condensation type, which causes poor curing if carboxylic acid is present in the photosensitive layer, the addition type does not contain carboxylic acid. Even if it exists, hardening will occur sufficiently. Since carboxylic acid can be present in the photosensitive layer in this way, it has the characteristic that it can be developed with a developer mainly containing water or alkaline water.

Here, the -CH=CH- group includes a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, an alkenylene group,
Examples include rrukynyl group and alkynylene group, and aromatic -
CH=CH- bonds are not included.

The silicone rubber of the present invention contains a polyvalent hydrogen organopolysiloxane and two or more -CH═CH atoms per molecule.
- Obtained by reaction with a polysiloxane compound having a bond, preferably (1) 100 parts by weight of an alkaline polysiloxane having at least two alkenyl groups (preferably vinyl groups) directly bonded to a silicon atom in one molecule; (2) 0.1 to 1000 parts by weight of an organohydrodiene polysiloxane having at least two (2) SiH bonds in one molecule (3) Addition catalyst 0.0QOO 1 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 organic groups other than the alkenyl group include substituted or unsubstituted alkyl groups and aryl groups. Ingredient (1)i
It is also optional to have a trace amount of hydroxyl group. Ingredient (2)
reacts with component (1) to form silicone rubber,
It also plays the role of imparting adhesion to the photosensitive layer. Ingredients (2
The hydrogen group in ) may be located at the end of the molecular chain or in the middle (5), and the organic group other than hydrogen is selected from the same ones as in 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) may be linear, cyclic, or branched, and it is preferable from the viewpoint of rubber physical properties that the molecular weight of at least one of them exceeds 1.000. The molecular weight of (1) is 1
．． It is preferable that it exceeds 000.

Examples of component (1) include α,ω-divinylpolydimethylsiloxane, (methylvinylsiloxane) (dimethylsiloxane) copolymer having methyl groups at both ends,
Component (2) includes polydimethylsiloxane having hydrogen groups at both ends, α,ω-dimethylpolymethylhydrogensiloxane, methylhydrogensiloxane (dimethylsiloxane) copolymer having methyl groups at both ends, and cyclic polymethylhydrocarbon. Examples include diene siloxane.

Addition catalyst for component (3): Any catalyst may be selected from known catalysts, but platinum-based compounds are particularly preferred, and examples include simple platinum, platinum chloride, chloroplatinic acid, and platinum at the 8-position of the olefin. In order to control the curing rate of these compositions, crosslinking inhibitors such as vinyl group-containing alkalis such as tetracyclo(methylvinyl)siloxane, polysiloxanes, and carbon-carbon triple bond-containing alcohols may be added. It is possible.

In these compositions, an addition reaction occurs and curing begins when the three components are mixed, but the curing rate is characterized by rapidly increasing 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 such that the temperature conditions are within a range that does not change the characteristics of the substrate and the photosensitive layer. In addition, it is preferable to maintain the temperature at a high temperature until it is completely cured in order to maintain the stability of the adhesive force with the photosensitive layer.

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

In the waterless lithographic printing original plate described herein, it is optional to further coat various silicone rubber layers on the silicone rubber layer having the characteristics of the present invention, and it is also possible to coat the photosensitive layer with the silicone rubber layer. It is also optional to provide an adhesive layer between the photosensitive layer and the silicone rubber layer for the purpose of increasing the strength or preventing poisoning of the catalyst in the silicone rubber composition. To protect the surface of the silicone rubber layer, a durable 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. You can.

The waterless lithographic printing original plate according to the present invention is exposed through a transparent original and then developed with a developer capable of dissolving or swelling the photosensitive layer in the image area or a developer capable of swelling the silicone rubber layer. In this case, there are cases in which the photosensitive layer in the image area and the silicone rubber layer thereon are removed, and cases in which only the silicone rubber layer in the image area is removed, and this can be controlled by the strength of the developer.

The developer used in the present invention may be one known as a developer for photosensitive lithographic printing original plates that do not require dampening water. G'” (manufactured by Esso Chemical:
aliphatic hydrocarbons (trade name of aliphatic hydrocarbons) or gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, xylene, etc.),
Alternatively, a halogenated hydrocarbon (such as trichlene) to which the following polar solvent is added is suitable.

・Alcohols (methanopeechnopebenzyl alcohol, etc.) ・Ethers (methyl cellosolve, ethyl cellosolve,
Butyl cellosolve, methyl calpitol, ethyl calpitol, butyl calpitol, dioxane, etc.) Ketones (acetone, methyl ethyl ketone, etc.) Ester ethyl acetate, methyl cellosolve acetate,
Cellosolve acetate, carpitol acetate, etc.) In addition, water may be added to the above organic solvent-based developer, or the above organic solvent may be solubilized in water using an activator, or an alkali agent such as carbonic acid may be added thereto. Added sodium, monoethanolamine, jetanolamine, triethanolamine, sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, sodium borate, etc., or in some cases, simply add tap water or alkaline water. It can be used as a developer.

Furthermore, dyes such as crystal violet and astrazone dye can be added to the developer to dye the image area at the same time as development.

Development can be carried out by a known method, such as rubbing with a developing pad containing a developer as described above, or pouring a developer onto the printing plate and then rubbing with a developing brush. As a result, the silicone rubber layer and photosensitive layer in the image area are removed, exposing the surface of the substrate or primer layer, which becomes the ink-receiving area.Alternatively, only the silicone rubber layer in the image area is removed and the photosensitive layer is exposed. The exposed part becomes the ink receiving area.

〔Effect of the invention〕

The waterless lithographic printing original plate according to the present invention has a layer structure in which a photosensitive layer is laminated on a substrate, and a silicone rubber layer crosslinked by addition reaction is laminated in this order. Containing a photosensitive polymer compound that is soluble in water or alkaline water and has a group represented by formula (I) or (I[) and at least one carboxylic acid group or a salt thereof in a side chain. As a result, a waterless lithographic printing original plate can be obtained, which has little sensitivity variation depending on the printing environment, can be processed with a relatively mild developer, and has no deterioration in image reproducibility over time.

Next, the present invention will be explained with reference to Examples, but the present invention is not limited thereto.

Example 1 The following composition for a brimer layer was applied to a 0.3 mm smooth aluminum plate degreased in a conventional manner to give a dry weight of 8.0 g/m', and heated at 120°C for 2 minutes. , dry hardened.

Milk casein 98 parts by weight Glyoxal solution (40% aqueous solution, Wako Pure Chemical Industries @) 2 parts by weight γ-glycidoxypropyltri(β-methoxyethoxy)silane 3 parts by weight Potassium hydroxide 4 parts by weight Pure
2000 parts by weight of water The aluminum plate coated with the above primer layer was immersed for 1 minute in a dyeing liquid having the composition shown below, and after dyeing, it was washed with water and dried at room temperature.

1 part by weight Pure water 2000 parts by weight The following photosensitive composition was coated on the aluminum plate coated with the dyed primer layer so as to have a dry weight of Ig/m° and dried at 100°C for 1 minute.

Crystal violet 0.05 parts by weight Methyl ethyl ketone 40g Ethylene glycol monomethyl ether 20g Propylene glycol monomethyl ether 55g Water
Next, 2.5 g of the following silicone rubber composition was applied on the photosensitive layer by dry weight.
It was coated to a concentration of 0 g/m' and dried at 140°C for 2 minutes to obtain a cured silicone rubber layer.

α,ω-divinylpolydimethylsiloxane (average molecular weight 300,000) 90 parts by weight α,ω-dimethylpolymethylhydrodiene siloxane (average molecular weight 2.500) 6 parts by weight Olefin-chloroplatinic acid (10% toluene solution) 20 Parts by weight Inhibitor (10% toluene solution) 10 parts by weight Isopar G (manufactured by Enso Chemical ■) 1400 parts by weight Toluene
210 parts by weight of a single-sided matted polypropylene film having a thickness of 9 μm was laminated on the surface of the silicone rubber layer obtained as described above to obtain a photosensitive lithographic printing original plate that did not require dampening water.

A positive film was layered on this printing original plate and vacuum-adhered to it using Nuark's FT26V [IDN5 ULTRA-PLII].
3 by S FLIP-TOPPLATE MAKER
After 0 count exposure, peel off the laminate film,
Immersed for 1 minute in a developer consisting of 8 parts by weight of benzyl alcohol, 3 parts by weight of sodium isoprobylnafucrene sulfonate, 1 part by weight of sodium carbonate and 88 parts by weight of water,
When lightly rubbed with a development pad, the photosensitive layer and silicone rubber layer in the unexposed areas were removed. In this way, a lithographic printing plate requiring no dampening water was obtained that faithfully reproduced the image of the positive film over the entire surface of the printing plate.

Using this plate, Toyo Ink 79 TOYOKIl' was printed on a Heidelberg GTO printing machine with the dampening water supply device removed.
When printed with lG ULTRA TIIK Aquares G black ink, a printed matter showing faithful image reproducibility was obtained.

Example 2 A photosensitive primer liquid having the composition shown below was applied onto a degreased aluminum plate having a thickness of 0.3 mm and dried at 140° C. for 1 inch. The coating weight after drying was 4 g/m'.

Epicoat 1255-HX-30 (30% solution) (oiled shell epoxy side: condensate of bisphenol A and epichlorin) 5 parts by weight Takenate D-11ON (75% solution) (manufactured by Takeda Pharmaceutical Co., Ltd.: polyfunctional isocyanate compound > 15 parts by weight Pentaerythritol triacrylate 1 part by weight Ethyl 7-methylthioxanthone-3-carboxylate 0.5 parts by weight Victoria Pierple BOH 0.005 parts by weight 0.01 parts by weight Methyl ethyl ketone 30 parts by weight Propylene glycono L monomethyl ether Acetate 30 parts by weight Polyvinyl cinnamate 21.8 g, 2.2'-azobis(2
, 4-dimethylvaleronitrile) 0.3 g, 3-mercaptopropionic acid 5.3 g and methyl ethyl ketone 4
0g was added and reacted at 60°C for 5 hours. After the reaction, 60 g of methyl ethyl ketone was added to dilute the mixture, and the mixture was poured into water to precipitate Polymer 7. The acid value of this polymer was 107, and the weight average molecular weight measured by GPC (gel permeation chromatography) was 103,000. This polymer will be referred to as Polymer (A).

The following photosensitive solution was prepared using polymer (A), and applied using a wheeler onto an aluminum plate coated with the primer layer described above, and dried at 100° C. for 1 minute. The coating weight after drying is 1. It was Og/m'.

Polymer (A) 3 parts by weight PF of condensate of P-diazodiphenylamine and formaldehyde, salt 01 parts by weight/11 Dihexyl phthalate 0.2 parts by weight Megafac F177 (manufactured by Dainippon Ink ■: fluorine-based nonionic surfactant) 0 .02 parts by weight Crystal violet 0.05 parts by weight Ethylene glycol monomethyl ether 10 parts by weight Methyl ethyl ketone 40 parts by weight Propylene glycol monomethyl ether 50 parts by weight Water 5 parts by weight Subsequently, the following silicone rubber composition was applied on the photosensitive layer by dry weight. Apply to 1.7g/m', ° 140℃, 2
After drying for a minute, a cured silicone rubber layer was obtained.

α, ω-Divinylpolydimethylsiloxane (average molecular weight 600,000) 90 parts by weight α, ω-dimethylbolyhydride dimethylsiloxane (average molecular weight 2.500) 3 parts by weight Olefin-chloroplatinic acid (10% toluene solution) 20 parts by weight Part inhibitor (10% toluene solution) 10 parts by weight Isopar G (manufactured by Enoso Chemical) 1400 parts by weight Toluene
210 parts by weight A single-sided capped polypropylene film having a thickness of 12 μm was laminated on the surface of the silicone rubber layer obtained as described above, and a waterless planographic plate was prepared.
A printing original plate was obtained.

After imagewise exposing this printing plate in the same manner as in Example 1,
When the printing plate was immersed in the weakly alkaline water developer used in Example 1 for 1 minute and the surface was rubbed with a developing bat to remove the unexposed silicone rubber layer and photosensitive layer, a positive film image was formed over the entire surface of the printing plate. A faithfully reproduced waterless planographic printing plate was obtained.

Example 3 A photosensitive solution having the following composition was applied to the aluminum substrate coated with the 8 g/rri' casein primer layer used in Example 1, and dried at 100° C. for 1 minute.

The dry coating weight was 1.0 g/m'.

Polymer (A) used in Example 2 was hydroxylated (90 parts by weight) 10% methyl cellosolve solution neutralized with IJium 7-methylthioxanthone-3-1 parts by weight Ethyl carboxylate 0 Icocrystal violet 0 1 parts by weight Methyl ethyl ketone 60 parts by weight Fluorine nonionic surfactant 0.02 parts by weight Subsequently, the following silicone rubber composition was applied to the photosensitive layer at a dry weight of 1.4 g/
m' and dried at 140°C for 2 minutes to obtain a cured silicone rubber layer.

α,ω-Divinylpolydimethylsiloxane (average molecular weight 600,000) 90 parts by weight α,ω-dimethylpolymethylhydrosynsiloxane (average molecular weight 2,500) 5 parts by weight Olefin-chloroplatinic acid (10% toluene solution) 20 Part by weight inhibitor (
10% toluene solution) 10 parts by weight CH2=CH
CH2-5i (○CH3)3 1 part by weight KF41
0 (manufactured by Shin-Etsu Chemical: Silicone mold release agent) 0.5 parts by weight Isopar G (manufactured by Esso Chemical ■) 1400 parts by weight Toluene 210 parts by weight The plate prepared as above was laminated with polyethylene terephthalate with a thickness of 8 microns. This was used as a printing plate.

After imagewise exposure to this printing original plate in the same manner as in Example 1, 50
After immersing the printing plate in warm water at ℃ for 30 seconds, the plate surface was rubbed with a sponge for 30 seconds to remove the unexposed silicone rubber layer and photosensitive layer, resulting in a waterless lithographic plate that faithfully reproduced the positive film image over the entire surface of the printing plate. A printed version was obtained.

Claims (1)

[Claims] A substrate, a photosensitive layer provided on the substrate, and an addition reaction between a ▲ mathematical formula, chemical formula, table, etc. group provided on the photosensitive layer and a -CH=CH- group. In a waterless lithographic printing original plate consisting of a silicone rubber layer crosslinked by , the photosensitive layer has at least two side chains of the following general formula (I) or (II): ▲There are mathematical formulas, chemical formulas, tables, etc.▼...・(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (However, A: aryl group, substituted aryl group, furyl group, or chenyl group B: hydroxyl group, alkoxy group, aryl group, substituted aryl group Or alkyl group ) and at least one carboxylic acid group or a salt thereof in the side chain, and is soluble in water or alkaline water. Printing original plate.