JP2791393B2 - Photosensitive layer for printing plate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a photosensitive layer for a printing plate, and more particularly, to a photosensitive layer for a printing plate excellent in ink inking property and storage stability.

b. Conventional technology It has been conventionally known to apply a diazo photosensitive agent to a photosensitive layer for a lithographic printing plate. In particular, in a photosensitive lithographic printing plate having a photosensitive layer formed on an aluminum thin plate, a diazo photosensitive agent is an indispensable element.

In recent years, many of the materials for forming the photosensitive layer of these photosensitive lithographic printing plates include a diazo-based photosensitizer, a polymer that can be mixed with the photosensitizer, and dyes, pigments, preservatives, and coatability that are added as necessary. It is made of a plasticizer or a surfactant for improving the quality.

Among the materials that form these photosensitive layers, those that have a significant effect on the characteristics of the photosensitive lithographic printing plate, such as image reproducibility, development stability, inking property, printing durability, and storage stability, are high molecular weight polymers. Often it is.

As the polymer, generally, JP-A-50-118802,
JP-A-53-120903, JP-A-54-88403, JP-B-57-4
Various acrylic copolymers disclosed in Japanese Patent Application No. 3890 and Japanese Patent Application No. 63-151570 have been used. These copolymers are water-insoluble and have a hydroxyl group (-OH group) necessary for adhesion to an aluminum sheet, and a hydrophilic functional group such as a carboxylic acid group (-COOH group) that can be developed in a weak alkaline aqueous solution. Is an acrylic copolymer.

c. Problems to be Solved by the Invention However, because these copolymers are hygroscopic resins, photosensitive lithographic printing plates using these as the material of the photosensitive layer are insensitive to being applied after development during plate making. There is a drawback that the gum loses due to the greased gum and causes troubles such as poor ink deposition during printing, and when the photosensitive lithographic printing plate is stored, it absorbs the moisture in the atmosphere, and it is stored for a long time Stability is not very good. That is, there are drawbacks in that the development is delayed and the non-image portion is stained during printing.

In order to improve poor ink deposition, a technique of mixing a lipophilic polymer compound into a photosensitive layer is known. For example, JP-A-55-527 and JP-A-63-204248 disclose styrene-maleic anhydride copolymers or substituted phenols.
A technique for adding an aldehyde condensation polymer is disclosed.

However, it has been found that these methods have various disadvantages. That is, due to poor compatibility with the main acrylic copolymer, coating unevenness occurs when coating on the support, or developability deteriorates when stored for a long period of time, causing printing stains and the like. Was.

As a method for preventing moisture absorption in the atmosphere, Japanese Patent Application
No. 321449 discloses a technique in which a nonionic cellulose derivative such as hydroxyethylcellulose, hydroxypropylcellulose, or hydroxybutylcellulose is provided as an overcoat layer of a photosensitive layer, but coating unevenness occurs in actual production. And there were many technically difficult problems.

The present inventors have conducted intensive studies to improve such disadvantages, and as a result, by mixing a specific copolymer in the photosensitive layer, the ink inking property and the moisture resistance are excellent, and the developability over a long period is improved. It has been found that a photosensitive layer having no change can be obtained, and the present invention has been accomplished.

d. Means for Solving the Problems That is, the present invention provides a photosensitive layer containing an acrylic copolymer having a hydroxyl group and a carboxylic acid group and a diazo-based photosensitizer, having one-terminal reactivity represented by the following general formula (I): A photosensitive layer for a printing plate, comprising a copolymer containing silicone, stearyl acrylate, and mono (2-methacryloxyethyl) hexahydrophthalate as copolymer components, and comprising a general formula (I) shown below. A copolymer containing one-terminal reactive silicone, stearyl acrylate and mono (2-methacryloxyethyl) hexahydrophthalate as a copolymer component is contained in the photosensitive layer in an amount of 5.0 to 30% by weight.
The present invention provides a photosensitive layer for a printing plate, which is characterized by being mixed.

Examples of the one-terminal reactive silicone represented by the general formula (I) include, for example, 3-methacryloxypropyltris (trimethylsiloxy) silane (trade name: Silaprene)
TMO701; Chisso Corporation), Silaplane FMO720 Chisso Corporation), Silaplane FMO725 (Chisso Corporation)
Manufactured).

One-terminal reactive silicone, a copolymer containing stearyl acrylate and mono (2-methacryloxyethyl) hexahydrophthalate as copolymer components (hereinafter referred to as a mixed copolymer) is a kind of acrylic copolymer. And other components can be copolymerized in addition to copolymer components such as one-terminal reactive silicone, stearyl acrylate, and mono (2-methacryloxyethyl) hexahydrophthalate. Other components can be arbitrarily selected as long as they are general unsaturated compounds. In addition, for example, 2-hydroxyethyl methacrylate, ethyl methacrylate, acrylonitrile and the like are preferable.

In the mixed copolymer, the content of the one-terminal reactive silicone is preferably from 5 to 50% by weight, more preferably from 10 to 40% by weight, based on the total amount of the copolymer. If it is less than 5% by weight, the effect of moisture resistance cannot be obtained, and if it is more than 50% by weight, the ink inking property is deteriorated. Further, the content of stearyl acrylate is preferably from 10 to 90% by weight, more preferably from 20 to 80% by weight, based on the total amount of the copolymer. 10% by weight
Below, the effect of improving the ink inking property cannot be obtained, and 90
If it is more than 10% by weight, it is difficult to dissolve in an alkali developer. The content of mono (2-methacryloxyethyl) hexahydrophthalate is preferably from 10 to 90% by weight, more preferably from 20 to 80% by weight, based on the total amount of the copolymer. Ten
If it is less than 90% by weight, it will be difficult to dissolve in an alkali developing solution.

The mixed copolymer is preferably mixed with the photosensitive layer for a printing plate of the present invention in a range of 5.0 to 30% by weight based on the total weight of the photosensitive layer. If the content is less than 5.0% by weight, the gum is easily lost, and the improvement of the ink deposition property cannot be obtained.
No moisture resistance effect is obtained. If it is 30% by weight or more, the printing durability deteriorates.

The acrylic copolymer contained in the photosensitive layer of the present invention can be prepared by copolymerizing an addition polymerizable unsaturated compound having a hydroxyl group and an addition polymerizable unsaturated compound having a carboxylic acid group.

Examples of the addition-polymerizable unsaturated compound having a hydroxyl group include (1) acrylates and methacrylates having a hydroxyl group, for example, 2-hydroxyethyl or 2-hydroxypropyl acrylate, hydroxydodecyl, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, Dipropylene glycol, polyethylene glycol, polypropylene glycol, trimethylolpropanepentaerythritol, 2
Acrylates and methacrylates such as -hydroxy-3-phenoxypropyl and 2-hydroxy-3-methylphenoxypropyl; (2) acrylates and methacrylates of oligoesters having a hydroxyl group, for example, polyester diols of succinic acid and propylene glycol, maleic acid Polyester diol with propylene glycol, polyester diol with phthalic acid and propylene glycol, polyester diol with hexahydrophthalic acid and propylene glycol, polyester diol with tetrahydrophthalic acid and propylene glycol, tetrahydrophthalic acid with propylene glycol and glycerin- Acrylates and methacrylates such as polyester diol with 1-butyl ether; Acrylamide and methacrylamide or derivatives thereof, may for example hydroxyethyl, hydroxyphenyl, hydroxynaphthyl, acrylamide or methacrylamide such as N- hydroxyethyl -N- methyl, and the like.

Examples of the addition-polymerizable unsaturated compound having a carboxylic acid group include acrylic acid, methacrylic acid, mono (2-methacryloxyethyl) hexahydrophthalate, and mono (2
-Acryloxyethyl) hexahydrophthalate and the like.

The above-mentioned acrylic copolymer may further be copolymerized with another addition polymer unsaturated compound. As the other addition-polymerizable unsaturated compound, a general unsaturated compound can be arbitrarily used, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl,
n-amyl, n-hexyl, 2-ethylhexyl, octyl, lauryl, dodecyl, cyclohexyl, tetrahydrofuryl, benzyl, stearyl, dimethylaminoethyl, diethylaminoethyl, chloroethyl, aryl (eg, phenyl, tolyl, naphthyl, etc.), glycidyls Acrylic esters or methacrylic esters, and nitriles such as acrylonitrile and methacrylonitrile are mentioned.

In the acrylic copolymer, the content of the addition-polymerizable unsaturated compound having a hydroxyl group is preferably from 10 to 70% by weight, more preferably from 20 to 70% by weight, based on the total amount of the acrylic copolymer.
~ 60% by weight. When the content is less than 10% by weight, the adhesion to the aluminum support is deteriorated, and when the content is more than 70% by weight, expansion of the image portion at the time of development tends to occur. Further, the content of the addition polymerizable unsaturated compound having a carboxylic acid group is desirably 2.0 to 40% by weight, more preferably 3.0 to 30% by weight, based on the total amount of the acrylic copolymer. If it is less than 2.0% by weight, it will be difficult to dissolve in a weakly alkaline aqueous solution and the developability will be poor. On the other hand, if it is 40% by weight or more, gelation occurs depending on the reaction conditions.

The acrylic copolymer is preferably contained in an amount of about 40 to 90% by weight based on the total weight of the photosensitive layer. If it is less than 40% by weight, the inking property and printing durability are poor, and if it is more than 90% by weight, the developability is poor.

Examples of the diazo-based photosensitive agent added to the photosensitive layer used in the present invention include conventionally known photosensitive agents such as diazo resins, P-quinonediazides, and diazo compounds (compounds having two or more diazo groups). Particularly preferred are diazo resins. As diazo resin, Japanese Patent Publication No. 40-8611
And diazodiarylamines described in US Pat. No. 2,922,715 and US Pat. No. 2,946,683, and an active carbonyl compound such as formaldehyde and acetaldehyde. Examples of the diazoarylamine include 4-diazodiphenylamine, 4-diazo-3-methylphenylamine, 4-diazo-3-methylphenylamine, 4-diazo-4-methoxydiphenylamine,
4-diazo-3-methoxydiphenylamine and the like can be mentioned.

Most preferably, the diazo resin is used in the form of an organic salt or an inorganic salt. Examples of compounds that form an organic salt by combining with the above diazo resin include JP-B-40-2203,
There are compounds described in JP-B-41-6813, JP-B-47-1167, etc., for example, benzenesulfonic acid, P-
Toluenesulfonic acid, 2,5-xylenesulfonic acid, linear or side chain type dodecylbenzenesulfonic acid (commonly called dodecylbenzenesulfonic acid), 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid, methanyl yellow, 2-chloro Examples thereof include toluene-4-sulfonic acid, and alkali metal salts, alkaline earth metal salts, and ammonium salts thereof.

Examples of the compound which forms an inorganic salt by combining with the above diazo resin include JP-B-40-2203 and JP-A-54-9861.
No. 3, compounds described in U.S. Pat.No. 4,093,465, and examples thereof include borofluoric acid, hexafluorophosphoric acid, phosphotungstic acid, thiocyanic acid, and alkali metal salts and ammonium salts thereof. .

The diazo-based photosensitizers can be used alone or in combination, and the content is preferably about 5 to 30% by weight based on the total weight of the photosensitive layer.

A dye or pigment can be added to the photosensitive layer of the present invention for coloring. As these dyes or pigments, dyes or pigments which are not eluted by the developing solution from the image portion (cured portion by irradiation with ultraviolet rays) at the time of developing the photosensitive layer are desirable.

Examples of the dye include crystal violet, malachide green, Victoria Blue, methylene blue, ethyl violet, rhodamine B, and the like, and basic oily dyes that are derivatives thereof. Commercially available such dyes include Victoria Pure Blue BOH
(Hodogaya Chemical Industry Co., Ltd.), Oil Blue # 603 (Orient Chemical Industry Co., Ltd.), Permanent Blue # 47
(Manufactured by Daido Chemical Co., Ltd.).

Examples of the pigment include phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone red, and indanthrene blue. Commercially available products include Neozapon Blue FLE (produced by Birdish Aniline Co., Ltd.), Oil Blue BOS (produced by Orient Chemical Co., Ltd.), and Spiron Blue GNH (produced by Hodogaya Chemical Co., Ltd.). is there.

The content of the dye is about 0.1 to the total weight of the photosensitive layer.
To 4.0% by weight, more preferably 0.5 to 3.0% by weight. The content of the pigment is about 1.0 to 5.0% by weight, more preferably 2.0 to 4.0% by weight based on the total weight of the photosensitive layer.
% By weight.

Further, a preservative may be added to the photosensitive layer of the present invention. As a preservative, for example, citric acid, tartaric acid, lactic acid, 5-sulfosalicylic acid, oxalic acid, DL-malic acid,
2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid and the like. The content of these preservatives is about 0.1 to 4.0% by weight, more preferably 0.5 to 3.0% by weight, based on the total weight in the photosensitive layer.

Furthermore, a plasticizer or a surfactant can be added for the purpose of improving the coating property of the photosensitive layer and improving the inking property of the photosensitive layer. As the plasticizer, for example, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, diisononyl phthalate, ethyl phthalyl ethyl glycol, dimethyl Isophthalate and the like can be mentioned.

The content of the above plasticizer is, based on the total weight of the photosensitive layer, about
0.5 to 3.0% by weight, more preferably 0.6 to 2.0% by weight
Range.

Surfactants include sorbitan monooleate, sorbitan stearate, sorbitan monostearate, sorbitan mosekisulate, sorbitan monolaurate, polyoxyethylene noniphenyl ether,
Examples thereof include polyoxyethylene octyl phenyl ether.

The content of the surfactant is about 0.4 to 2.0% by weight, more preferably 0.6 to 1.6% by weight based on the total weight of the photosensitive layer.
% By weight.

When the photosensitive layer of the present invention is formed on a support, the two acrylic copolymers of the present invention, a diazo-based photosensitizer and, if necessary, a dye, a pigment, and a preservative,
A plasticizer, a surfactant, or the like may be used in combination with an organic solvent such as methanol, methylene chloride, ethyl acetate, tetrahydrofuran, N-N-dimethylformamide, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, or the like. It is dissolved in a mixed solvent of more than one kind, coated on a support using various coating machines (for example, a wheeler, a roll coater, a bar coater, an extrusion coater, etc.) and dried.

As the support, paper, plastic film, or a metal plate of copper, zinc, aluminum, stainless steel, or the like,
Further, a composite material in which two or more of these materials are combined can be used, and among these, an aluminum plate polished with a brush or a ball, an aluminum plate polished with a brush and then anodized, and anodized with an electrolytic polishing. A turned aluminum plate or an aluminum plate subjected to a combination of these processes is suitable.

The aluminum plate that has undergone such pretreatment is further subjected to a chemical conversion treatment with alkali silicate, zirconium fluoride, alkyl titanate, trihydroxybenzoic acid,
Boehmite treatment, coating treatment with an aqueous solution of strontium acetate, zinc acetate, magnesium acetate, calcium benzoate, or the like, and coating treatment with polyvinylpyrrolidone, polyaminesulfonic acid, poly-2-hydroxyethyl acrylate, or the like can be performed as a post-treatment.

The photosensitive layer of the present invention coated on the support is exposed to actinic rays such as ultraviolet rays, and is developed with a weakly alkaline aqueous solution as a developer to obtain an image.

As a weak alkaline aqueous solution used as a developer,
For example, (1) metal salts of weak acids, for example, sodium salts of silicic acid, metasilicic acid, orthosilicic acid, phosphoric acid, pyrophosphoric acid, metaphosphoric acid, hexametaphosphoric acid, carbonic acid, tartaric acid, boric acid, etc.
Metal salts such as lithium salts and potassium salts; (2) ammonia and its derivatives, for example, alkylamines (for example, amine compounds such as monomethyl, dimethyl, trimethyl, monoethyl, diethyl, and triethyl), or alkanolamines (for example, monoethanolamine) , Diethanolamine, triethanolamine, diisopropanolamine) and the like.

In order to improve the dissolution rate of the unexposed portion of the photosensitive layer according to the invention, an activator and / or a solvent can be added to the above weakly alkaline aqueous solution. Examples of the activator include anionic surfactants such as sulfates of alcohols having 8 to 22 carbon atoms (eg, polyoxyethylene alkyl sulfate soda salt) and alkylaryl sulfonates (eg, sodium dodecylbenzene sulfonate, polyoxyethylene). Dodecylphenyl sulfate soda salt,
Alkyl naphthalene sulfonate, sodium naphthalene sulfonate, formalin condensate of sodium naphthalene sulfonate), sodium dialkyl sulfosuccinate,
Fatty acid amide sulfonate, alkyl phosphate ester,
Alkyl ether phosphates and the like can be used.

As the solvent, alcohols and ethers are preferable, but a solvent that does not dissolve in water (20 ° C.) by 10% or more is most preferable. Examples of such a solvent include benzyl alcohol and DL-α-phenylethyl alcohol as alcohols. There are 2-phenylethyl alcohol and the like, and examples of the ethers include phenyl cellosolve and propylene glycol monobutyl ether.

As the composition of the developer, the above weakly alkaline compound 0.1
~ 3.0% by weight, surfactant 0.5 ~ 2.0% by weight, solvent 0 ~ 2.0
Those containing by weight are preferred.

e. Action The mixed copolymer of the present invention was mixed with an acrylic copolymer having a hydroxyl group and a carboxylic acid group and a photosensitive layer containing a diazo-based photosensitive agent, coated on a support, and dried to be used for mixing. The copolymer thus formed forms a layer on the surface of the photosensitive layer. In addition, since the layer of this copolymer has no hygroscopicity and strong oil sensitivity, it does not lose the gum due to the desensitized gum at the time of plate making, and has good ink inking property.

Further, since the copolymer layer is resistant to moisture and can be dissolved in an alkali developing solution, deterioration of the entire photosensitive layer due to moisture is prevented, and the developability of the photosensitive layer itself is not deteriorated.

Therefore, the photosensitive printing plate using the printing plate photosensitive layer of the present invention has no change in developability over a long period of time, is excellent in ink adhesion during printing, has no adverse effect on printing durability, and has no stain. Printed matter is obtained.

Furthermore, in the photosensitive layer of the present invention, the two types of copolymers used as a mixture are both compatible with each other because they belong to acrylic copolymers, and have good compatibility with each other. It has excellent film properties.

f. Examples Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 An aluminum plate was washed with an 80% aqueous solution in which 3% of sodium hydroxide and 5% of sodium silicate were dissolved and polished with a brush, and then anodized with a sulfuric acid electrolyte for 1 minute (current density: 2 A / dm ² , Voltage 10V). Next, after washing with water, the film is treated with an aqueous solution containing 5% of sodium silicate for 10 seconds.
An anodized aluminum plate was produced. The aluminum plate is coated with a photosensitive solution having the following composition by using a spin coater (wheeler), and then dried at 80 ° C. for 3 minutes.
A photosensitive lithographic printing plate having a thickness of 1.7 g / m ² was obtained.

Composition of photosensitive solution Acrylic copolymer (1) 2.5 g Copolymer (A) 0.5 g Diazo-based photosensitizer (1) (dodecylbenzenesulfonate of 4-diazodiphenylamine and formaldehyde condensate) 0.3 g Oil blue # 603 (Orient Chemical Industry Co., Ltd.)
0.1 g tartaric acid 0.03 g ethylene glycol monomethyl ether 90 g N-N-dimethylformamide 10 g The acrylic copolymer (1) was produced as follows.

Under a nitrogen stream, 0.3 g of azobisisobutyronitrile was added to 150 g of dioxane, the mixture was heated to 80 to 85 ° C., and a mixture having the following composition was dropped into the mixture with stirring.

2-Hydroxy-3-phenoxypropyl acrylate 40 g Methyl methacrylate 30 g Acrylic nitrile 10 g Acrylic acid 20 g After completion of the dropwise addition, stirring was continued for 5 hours, 150 g of dioxane was added, and the mixture was poured into water to precipitate the copolymer. The precipitate was redissolved in 2-methoxyethanol, dropped into water, purified, and dried in vacuum (70 ° C.) to obtain a copolymer (1).

A 20% by weight solution of this copolymer in 2-methoxyethanol was prepared, and its viscosity was measured to be 300 CPS (25 ° C.).

The copolymer (A) was obtained by polymerization with the following composition in the same manner as the acrylic copolymer (1).

Thyraplane TM0701 (manufactured by Chisso Corporation) 20 g stearyl acrylate 60 g mono (2-methacryloxyethyl) hexahydrophthalate 20 g A 20% by weight solution of this copolymer in 2-methoxyethanol was prepared, and the viscosity was measured. 160 CPS (25 ° C.).

Example 2 A photosensitive lithographic printing plate was obtained in the same manner as in Example 1 except that a photosensitive solution having the following composition was used.

Acrylic copolymer (1) 2.5 g Copolymer (B) 0.5 g Diazo compound (2) (2-methoxy-4-hydroxy-5-benzoylbenzenesulfonate of condensate of 4-diazodiphenylamine and formaldehyde) 0.3 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Industry Co., Ltd.) 0.1 g Ethylene glycol monomethyl ether 90 g N-N-dimethylformamide 10 g The above copolymer (B) is the same as the acrylic copolymer (1). And polymerized with the following composition.

Note that Thyraplane FM0711 (manufactured by Chisso Corporation) 20 g stearyl acrylate 30 g 2-hydroxyethyl methacrylate 30 g mono (2-methacryloxyethyl) hexahydrophthalate 20 g A 20% by weight 2-methoxyethanol solution of this copolymer was prepared. When the viscosity was measured, it was 180 CPS (25 ° C.).

Example 3 A photosensitive lithographic printing plate was obtained in the same manner as in Example 1 except that a photosensitive solution having the following composition was used.

Acrylic copolymer (1) 2.5 g Copolymer (C) 0.5 g Diazo photosensitive agent (3) (hexafluorophosphate of condensate of 4-diazo-3-methoxydiphenylamine and formaldehyde) 0.3 g Oil Blue # 603 0.1 g Ethylene glycol monomethyl ether 90 g N-N-dimethylformamide 10 g The copolymer (C) was obtained by polymerizing with the following composition in the same manner as the acrylic copolymer (1).

Sailaplane FM0711 (manufactured by Chisso Corporation) 20 g stearyl acrylate 30 g ethyl methacrylate 10 g acrylonitrile 20 g mono (2-methacryloxyethyl) hexahydrophthalate 20 g A 20% by weight 2-methoxyethanol solution of this copolymer was prepared. When the viscosity was measured, it was 180 CPS (25 ° C.).

Example 4 A photosensitive lithographic printing plate was obtained in the same manner as in Example 1 except that a photosensitive solution having the following composition was used.

Acrylic copolymer (1) 2.5 g Copolymer (D) 0.5 g Diazo compound (1) 0.3 g Oil blue # 603 0.1 g Ethylene glycol monomethyl ether 90 g N-N-dimethylformamide 10 g The above copolymer (D) ) Was obtained by polymerizing with the following composition in the same manner as in the acrylic copolymer (1).

Thyraplane FM0721 (manufactured by Chisso Corp.) 10 g stearyl acrylate 30 g 2-hydroxyethyl methacrylate 30 g acrylonitrile 10 g mono (2-methacryloxyethyl) hexahydrophthalate 20 g A 20% by weight 2-methoxyethanol solution of this copolymer was prepared. It was 190 CPS (25 ° C.) when prepared and measured for viscosity.

Comparative Example 1 A photosensitive lithographic printing plate was obtained in the same manner as in Example 1, except that a photosensitive solution having the following composition was used.

Acrylic copolymer (1) 3.0 g Diazo compound (1) 0.3 g Oil blue # 603 0.1 g Ethylene glycol monomethyl ether 90 g N-N-dimethylformamide 10 g Comparative example 2 Except for using a photosensitive solution having the following composition, In the same manner as in Example 1, a photosensitive lithographic printing plate was obtained.

Acrylic copolymer (1) 3.0 g Diazo compound (2) 0.3 g Victoria Pure Blue BOH 0.1 g Ethylene glycol monomethyl ether 90 g N-N-dimethylformamide 10 g The photosensitive lithographic printing plate obtained in Examples 1 to 4 above. In each case, there was no coating unevenness and the coating was uniform.

Negative films were vacuum adhered on the photosensitive layers of the various photosensitive lithographic printing plates obtained in Examples 1 to 4 and Comparative Examples 1 and 2, and irradiated with ultraviolet rays at a distance of 1 m for 30 seconds using a 2 kW high-pressure mercury lamp. After that, using a developing solution having the following composition, immersion and development were performed at room temperature for 20 seconds, and after washing with water, a desensitized gum solution (Arabia gum 8 ° Baume solution) was thinly applied, dried, and dried to obtain a planographic printing plate. I got

Developer composition 20% aqueous solution of potassium silicate 50 g Phenyl glycol PGH (manufactured by Nippon Emulsifier Co., Ltd.) 40 g potassium isopropyl naphthalene disulfonic acid 5 g potassium sulfite 2 g water 903 g offset printing machine (KOR type printing machine manufactured by Heidelberg) ), Printing was performed on high-quality paper with a commercially available ink, and the number of sheets (printing number) from the start of printing until a printed matter having a sufficient ink density was obtained, and the printing durability were also examined. Table 1 shows the results.

From the results shown in Table 1, it can be seen that the lithographic printing plate according to the present invention is excellent in ink deposition.

The various photosensitive lithographic printing plates obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were left in a high-humidity atmosphere at a temperature of 30 ° C. and a humidity of 80% for several days, after which the plates were made and proof-printed. ,
The number of days (preservability) at which the non-image area begins to cause background soiling was examined. Table 2 shows the results.

From the results in Table 2, it can be seen that the photosensitive lithographic printing plate according to the present invention has excellent storage stability.

f. Effects of the Invention According to the present invention, it is possible to obtain a photosensitive layer for a printing plate having excellent storage stability due to the effects of coating properties, ink adhesion, and moisture resistance.

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Claims (2)

(57) [Claims] 1. A photosensitive layer containing an acrylic copolymer having a hydroxyl group and a carboxylic acid group and a diazo-based photosensitizer contains a one-terminal reactive silicone represented by the following general formula (I), stearyl acrylate and mono (2- A photosensitive layer for a printing plate, characterized by mixing a copolymer containing (methacryloxyethyl) hexahydrophthalate as a copolymer component. 2. A photosensitive layer comprising a copolymer comprising a reactive silicone of one end having the general formula (I), stearyl acrylate and mono (2-methacryloxyethyl) hexahydrophthalate as copolymer components in a photosensitive layer. The photosensitive layer for a printing plate according to claim 1, wherein 30% by weight is mixed.