JPH0572740A - Composition of tacky adhesion preventive layer for photosensitive resin printing plate - Google Patents

Abstract

PURPOSE:To improve a release property from a photosensitive resin plate having resilience and to obviate the generation of wrinkles and the receipt of the influence of temp. and humidity by incorporating hydroxyalkyl celluloses and a plasticizer into the above compsn. CONSTITUTION:The compsn. contains >=2 kinds of the hydroxyalkyl celluloses having internal plasticity and excellent resilience and the plasticizer. The resilience is increased by the hydroxyalkyl celluloses in this way and the smaller releasing force is necessitated at the time of peeling, for example, a polyester film as a cover film. The cover film is thus more easily releasable with the smaller force. The easier peeling of the cover film is more preferable in a plate making stage but the harder peeling is preferable at the time of producing the photosensitive resin original plate or during the packaging and transportation and at the time of cutting the original plate to desired sizes. The peeling strength at the time of the plate making is, therefore, preferably 15 to 2g/cm. The tacky adhesion preventive layer remaining on the photosensitive resin layer when the cover film is peeled does not wrinkle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-sticking layer composition for a flexible photosensitive resin printing plate, especially a water-developable flexographic printing plate.

[0002]

2. Description of the Related Art Usually, in the process of forming a photosensitive resin into a printing plate,
A method in which an original film is brought into vacuum contact with the photosensitive layer of the photosensitive resin original plate and exposed to actinic rays is mainly used.

In recent years, in the field of business home printing, there is an increasing demand for a rubber-like flexible photosensitive resin relief plate, which tends to make the photosensitive resin original plate softer.

The surface of the photosensitive layer of the original plate is usually tacky, and when the hardness of the original plate is low, the tackiness is further increased. If the adhesiveness is strong, uniform adhesion cannot be achieved when the original drawing film is brought into close contact, and thus the reproducibility of the image is deteriorated. In addition, when the original film is peeled from the original plate after exposure, there is a problem in that peeling is caused by adhesion between the two and damage occurs to both.

In order to solve such a problem, the most commonly used method is a technique of applying a thin film of a polymer having low tackiness on the surface of a photosensitive resin. For example, JP-A-51-49803 (polyvinyl alcohol having a saponification degree of 90% or more), JP-A-52-110010 (a polymerization degree of 800 or more, a saponification degree of 70% to 90%),
JP-A-54-68224 (water-soluble polymer), JP-A-56-1
Japanese Patent No. 10941 (soluble polyamide) and the like are known.
However, these methods have the following problems.

When the polyvinyl alcohol thin film is provided, small wrinkles are generated on the surface of the original plate when the cover film is peeled off or when the original plate is bent inward or outward in the plate making process.
Small wrinkles remain on the relief surface and cause ink density unevenness on the printed matter.

Among water-soluble polymers, amorphous polymers except polyvinyl alcohol having a saponification degree of 90% or more (for example, alkyl cellulose, vinyl-based polymer maleic acid copolymer, etc.) are not sticky due to moisture absorption of the thin film. It rises significantly, and the adhesion of the target original film is hindered. Further, there is a problem such as blocking in the manufacturing process of the thin film.

Thin films other than water-soluble polymers have no humidity dependence, but in recent years, a type using water has become the mainstream for developing a photosensitive resin printing plate. Therefore, if the polymer is not a water-soluble or water-dispersible polymer, it is not preferable because the step of removing the thin film before development requires an additional step of removing the thin film with an organic solvent that dissolves the thin film.

By the way, when the photosensitive resin composition is used for flexographic printing plates, the non-adhesive coating layer is highly demanded because the photosensitive resin is more flexible and has a strong adhesive property, and the above-mentioned small wrinkles are particularly required. Occurrence problems are likely to occur. Therefore, a technique in which a release layer is further provided for a flexographic printing plate is disclosed in JP-A-57
-208556 and the technique of blending polyvinyl alcohol with a plasticizer to prevent wrinkles are disclosed in JP-A-2-113254.

However, the former application of the release agent not only increases the number of manufacturing steps, but further coating a non-adhesive coating layer on the release agent tends to cause coating defects, so that a high level coating technique is required. It On the other hand, the latter coating layer of polyvinyl alcohol containing a plasticizer is easily affected by humidity, and there is a drawback that the original purpose of non-tackiness is lost due to sticking of the coating layer due to moisture absorption under high humidity.

[0011]

As mentioned above, even in the prior art, there is still no suitable anti-adhesive material for water-developable and flexible photosensitive resin plates.

In particular, the problem of wrinkles is large. For example, when the peeling of the cover film is once interrupted and then the peeling is resumed, linear striped wrinkles are generated at the interrupted portions, so that the peeling of the cover film is generally interrupted. It is required to peel without using one machine, but there is an opportunity to interrupt the peeling due to a mistake in peeling operation, and it is difficult to completely prevent the generation of wrinkles. Further, when the photosensitive resin laminated body from which the cover film has been peeled off is deformed into a concave or convex shape, when it is returned to a normal flat surface, wrinkles are generated in the anti-adhesion layer. Therefore, the photosensitive resin laminate after peeling the cover film is dealt with by avoiding moving it as much as possible, but sometimes it is necessary to move it, and avoid bending deformation of the photosensitive resin laminate. It is not easy to move.

Therefore, in the present invention, the water-soluble or water-dispersible polymer has good adhesion to the original film, and even if the original plate is bent, no small wrinkles are formed and at the same time, it is prevented from being affected by humidity. The purpose is to provide a material for thin films.

[0014]

Means for Solving the Problems The inventors of the present invention have made extensive studies on the anti-adhesion layer composition to solve the above-mentioned drawbacks, and as a result, finally completed the present invention. That is, the present invention is an anti-adhesive composition for a photosensitive resin printing plate containing hydroxyalkyl cellulose and a plasticizer. The hydroxyalkyl cellulose used in the present invention includes hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl ethyl cellulose, etc., and the degree of polymerization is preferably 260 or more, particularly 800 or more, regardless of the synthetic method. In the present invention, the hydroxyalkyl cellulose is preferably used as a mixture of two or more kinds. Further, as the plasticizer blended in the composition of the present invention, low molecular weight polyalkylene glycols, urea, sorbitol, glycerin, and the like, and compounds generally called surfactants are included in the present invention as long as they have an effect as a plasticizer. .. Among them, polyethylene glycol is particularly preferable in terms of price, availability, safety and volatility. 2 for polyethylene glycol
It is a low molecular weight polyethylene glycol having an average molecular weight in the range of 00 to 5000, preferably 1000 to
The content of polyethylene glycol having an average molecular weight in the range of 2,000 is preferably 0.1 to 20% by weight, more preferably 1% by weight or more and less than 15% by weight, based on the hydroxyalkyl cellulose.

The composition of the present invention is used as an anti-adhesion layer in a photosensitive resin laminate for a photosensitive resin printing plate. As the laminate, an adhesive layer, a photosensitive resin layer and an anti-adhesion layer are formed on at least a support. It is composed of a layer and a cover film, and as a manufacturing method thereof, a cover film is coated with an anti-adhesion layer in advance, and a support is coated with an adhesive layer in advance. A method of laminating layer materials by a method such as pressure bonding is commonly used.

Polyethylene terephthalate film is most suitable as the cover film in terms of dimensional stability, heat resistance and mechanical performance, but polyethylene, polypropylene, polystyrene and other peelable materials may be used as a single or laminated coat. What has been done can be used. The surface of the cover film may be smooth, but it is more preferable if it has a so-called matte surface roughness of 5 μm or less. When applying the composition of the present invention on the cover film,
It is preferred to apply the hydroxyalkyl cellulose as an aqueous solution of 1-5%, preferably 1.5-2%. In addition to the hydroxyalkyl cellulose and the plasticizer, various surfactants may be added to the composition of the present invention in order to improve the coatability to the cover film.
An antiseptic agent may be blended for its water-soluble leaving stability.
The thickness of the anti-adhesion layer after drying is 0.1 to 10 μm, preferably 2 to 5 μm.

Next, the photosensitive resin composition in the photosensitive resin laminated body in which the composition of the present invention is used has components such as a filling polymer, a photocuring agent, a photosensitizer, a polymerization inhibitor, and other additives. However, depending on the type of the filling polymer that is the main component, for example, polyamide-based, polyurethane-based, polyvinyl alcohol-based, polyester-based,
Although the present invention may be applied to any known photosensitive layer, it is particularly preferably referred to as polyvinyl acetic acid type, but particularly preferably, a polymer and an ethylenically unsaturated compound which dissolve or swell in water or an aqueous developing solution ( And) or a polymer obtained by a method comprising a hydrophobic polymer and a photoinitiator. For example, JP-A-60-21451 and JP-A-60-173055.
It is known by the issue.

As the above-mentioned photosensitive resin composition, for example, (A) a hydrophobic polymer having a glass transition temperature of 5 ° C. or lower,
Photosensitization containing (B) a hydrophilic polymer, (C) an ethylenically unsaturated compound, (D) a solvent in which the solubility of the component (B) is higher than that of the component (A), and (E) a photopolymerization initiator Particles in a photosensitive resin composition, or a photosensitive resin printing original plate and a printing plate, in which a phase containing a hydrophobic polymer as a main component surrounds a phase containing a hydrophilic polymer as a main component in the photosensitive resin layer Are present as a dispersed phase, and a photosensitive resin composition and the like are listed, and in the present invention, these compositions are particularly preferable.

The glass transition temperature of the component (A) is 5
Examples of the hydrophobic polymer having a temperature of not higher than 0 ° C. include those used as general-purpose elastomers. Examples include polymers obtained by polymerizing conjugated diene hydrocarbons, copolymers obtained by polymerizing conjugated diene hydrocarbons and monoolefin unsaturated compounds, polymers containing no conjugated diene hydrocarbons, and the like. Be done. As the conjugated diene hydrocarbon, 1,3-butadiene, isoprene, chloroprene and the like are used. The conjugated diene hydrocarbons may be used alone or in combination of two or more.

As the mono-olefin unsaturated compound,
Styrene, α-methylstyrene, 0-methylstyrene,
m-methylstyrene, P-methylstyrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide vinyl acetate,
Acrylic acid ester, methacrylic acid ester and the like are used.

A polymer obtained by polymerizing a conjugated diene hydrocarbon or a copolymer obtained by polymerizing a conjugated diene hydrocarbon and a monoolefin unsaturated compound is a butadiene polymer or isoprene polymer. , Chloroprene polymer, styrene-butadiene copolymer, styrene-
Isoprene copolymer, styrene-chloroprene copolymer, acrylonitrile-butadiene copolymer, acrylonitrile-isoprene copolymer, acrylonitrile-chloroprene copolymer, methyl methacrylate-butadiene copolymer, methyl methacrylate-isoprene copolymer ,
Methyl methacrylate-chloroprene copolymer, methyl acrylate-butadiene copolymer, methyl acrylate-isoprene copolymer, methyl acrylate-chloroprene copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-isoprene-styrene Examples thereof include copolymers and acrylonitrile-chloroprene-styrene copolymers.

Examples of the polymer containing no conjugated diene hydrocarbon include elastomers containing a specific amount of chlorine and non-conjugated diene hydrocarbons. Those exhibiting rubber elasticity are polymers having a chlorine content of 50 to 10% by weight and a glass transition temperature (hereinafter referred to as Tg) of 5 ° C or less, such as polymerization of a monomer containing a chlorine atom, or chlorine. It results from the copolymerization of the atom-containing monomer with other monomers which are copolymerizable. It can also be obtained by reacting chlorine or an active substance containing chlorine with a polymer containing no chlorine atom. Specifically, the following can be mentioned. Epichlorohydrin polymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-propylene oxide copolymer and or epichlorohydrin rubber which is a copolymer of these and allyl glycidyl ether (Epichromer manufactured by Osaka Soda Industrial Co., Ltd., Goodvich HYDRIN, Nippon Zeon strain) GECHRON, Zeospan, Hercules Strains HERCLO
R], chlorinated polyethylene [Showa Denko KK, Erasulen, Osaka Soda Industrial Co., Ltd. Diisolac, Hoechst HO
RTALITZ, DOWCPE manufactured by Dow Chemical Co., Ltd., vinyl chloride copolymer, vinylidene chloride, chlorinated polypropylene, chlorinated ethylene-propylene rubber, and the like, and these polymers may be used alone or in combination of two or more kinds. The chlorine content of the polymer is 10-50% by weight, preferably 15-
It is 40% by weight, and if it deviates from this range, the flexibility is impaired, the thermal stability is deteriorated, the photosensitive resin composition becomes too hard, and coloring is likely to occur, which is not preferable. Since the conjugated diene hydrocarbon polymer containing a chlorine atom or its copolymer contains a carbon unsaturated bond in the main chain, it has a drawback that chemical stability such as weather resistance is inferior to that of a saturated bond alone. Further, since the physical properties of the photosensitive resin composition after light irradiation largely depend on the properties of the component (A) in the present invention, it is preferable that the component (A) is essentially a rubber elastic body. Therefore, its Tg needs to be 5 ° C or lower, and particularly preferably -10 ° C or lower.

The photosensitive resin composition used in the present invention is not limited to the polymer as the component (A), but also has an elastomer having good compatibility with and ozone resistance such as acrylic rubber and polyurethane elastomer. May be blended. The content of the component (A) in the entire composition is determined in consideration of physical properties and shape retention as a printing plate.
20% by weight or more, particularly 30% by weight or more is preferable, and from the viewpoint of photopolymerizability, 80% by weight or less, particularly 70% by weight or less is preferable.

The hydrophilic polymer as the component (B) is water,
Or, as a main component of water, it means a polymer that is soluble or swells (disperses) in a developing solution containing an alkaline aqueous solution, an acidic aqueous solution, an organic solvent, or a surfactant, a —CO ₂ M group,
-SO ₃ M group, (M is a hydrogen atom, group I, II, III element of the periodic table, amine, ammonium) having a hydrophilic group such as -NH ₂ , -OH, and is chain-like and has no cross-linking It is a polymer.
Examples of such hydrophilic polymers include polyvinyl alcohol (PVA) other than general-purpose resins such as carboxymethyl cellulose (meth) diene rubber obtained by copolymerizing acrylic acid and a diene compound, liquid polybutadiene modified with maleic anhydride, A particularly effective skeleton is a polymer having 50 to 50,000 equivalent / 10 ⁶ g of —COOM (M is a hydrogen atom, elements of groups I, II and III of the periodic table, amine and ammonium). Examples of the Group I, II and III elements include alkali metals such as sodium, potassium and lithium, alkaline earth metals such as calcium and magnesium, boron and aluminum. In the present invention, if the --COOM group is less than 50 equivalent / 10 ⁶ g, the affinity for water is poor and it is difficult to develop with neutral water.
When it exceeds 00 equivalent / 10 ⁶ g, the water-based ink resistance is poor, which is not preferable.

Specific examples of the hydrophilic polymer include -COOM group-containing polyurethane, -COOM group-containing polyureaurethane,
-COOM group-containing polyester, -COOM group-containing epoxy compound, -COOM group-containing polyamic acid, -COOM group-containing acrylonitrile-butadiene copolymer, -COOM group-containing styrene-butadiene copolymer, -COOM group-containing polybutadiene, polyacrylamide, polyacrylic Sodium acid, polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC),
Methyl cellulose (MC), polyethylene oxide, polyethylene imine, and derivatives of the compounds can be used, but are not limited thereto.

The compounds used to neutralize at least a part of the carboxyl groups contained in the hydrophilic polymer are lithium hydroxide, potassium hydroxide,
Sodium hydroxide and other alkali metal hydroxides, lithium carbonate, potassium carbonate, sodium carbonate and other alkali metal carbonates, potassium t-butoxide, sodium methoxide and other alkali metal alkoxides, calcium hydroxide, magnesium hydroxide, water Polyhydric metal hydroxides such as aluminum oxide, polyvalent metal alkoxides including aluminum isopropoxide, tertiary amines such as triethylamine and tri-n-propylamine, diethylamine, di-n-propylamine, etc. Primary amines Ethylamine, primary amines such as n-propylamine, cyclic amines such as morpholine, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth)
Examples thereof include amino group-containing (meth) acrylates such as acrylates, ammonium carbonate, ammonium salts, and the like. These may be used alone or in combination of plural kinds. The hydrophilic polymer may have a polyoxyalkylene chain as a hydrophilic part in addition to the -COOM group, and may contain an ethylenically unsaturated group so that it can act as a crosslinking agent.

As the component (B), a polymer having a hydrophilic group such as a hydroxyl group, an amino group and a sulfonic acid group and / or a polyoxyalkylene chain may be used together with the hydrophilic polymer. The content of the component (B) in the total composition is 5 to 50% by weight, especially 7 to 40% by weight, in consideration of the aqueous developability and the water resistant ink resistance.
30% by weight is particularly preferred. Further, it is essential that the content of the component (B) in the entire composition is lower than that of the component (A),
If the amount is larger than the amount of the component (A), the water resistant ink resistance deteriorates.

Component (C), the ethylenically unsaturated compound, contains at least one terminal ethylenic group, and this compound can form a polymer by free radical initiated chain growth addition polymerization. It is a thing. Suitable ethylenically unsaturated compounds are unsaturated esters of polyols, especially such esters with α-methylenecarboxylic acid, such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerol diacrylate, 1 , 3-Propanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,2,4-butanetriol tri (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, 1 , 6-Mexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate diallyl phthalate, fumaric acid diethyl ester, maleic acid dibutyl ester, and the like, and also N-methylmaleimide, N-ethylmaleimide, N- N such as lauryl maleimide Oligos such as maleimide compound, oligonitrile / budadiene di (meth) acrylate, oligonitrile / urethane (meth) acrylate, oligourethane di (meth) acrylate, oligobutanediene di (meth) acrylate, oligobutadiene / urethane di (meth) acrylate (Meth) acrylate may be used, and these may be used alone or in combination.

The content of the component (C) in the composition is preferably 1 to 50% by weight, and if it is less than 1% by weight, the photopolymerizability is impaired, and no image remains after development. On the other hand, if the amount is more than 50% by weight, the shape retaining property is impaired. Further, the plate after irradiation with light becomes hard and brittle, which makes it unsuitable as a plate material for flexographic printing, which is not preferable. More preferably 5
40% by weight.

Examples of the solvent in which the solubility of the component (B), which is the component (D), is higher than the solubility of the component (A) include solvents having high polarity. That is, it is a solvent which swells, disperses and dissolves the hydrophilic polymer (B) component, but has a small degree of swelling with respect to the hydrophobic polymer. Specific examples of such a solvent include water, an alcohol having 1 to 5 carbon atoms, and the like, and the water includes sodium alkylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium alkylsulfonate, and alkyl ether. It may contain a surfactant such as sodium sulfonate, a fatty acid, lithium hydroxide, potassium hydroxide, sodium hydroxide, sodium borate, sodium carbonate, sodium acetate, magnesium acetate, or a salt thereof. As alcohol, methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol,
Examples thereof include isobutyl alcohol, t-butyl alcohol, pentyl alcohol and neopentyl alcohol. Further, if they satisfy the requirement of (D), ester-based, ketone-based, amide-based solvents and the like can be mentioned.
Specifically, ethyl acetate, butyl acetate, isobutyl acetate,
Methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, methyl butyl ketone, formamide,
Examples thereof include dimethylformamide and dimethylacetamide. These solvents can be used alone or in combination as a mixed solvent.

The component (D) is contained in the entire composition in a limited amount in view of the performance of the photosensitive resin printing plate, and the range is 0.001 to 5% by weight based on the total composition. Preferably, it is from 0.001% to less than 2.0% by weight. When the content of the component (D) exceeds 5% by weight based on the total composition, the original plate before photopolymerization becomes soft and cold flow, plastic deformation, etc. occur, and also after photopolymerization and plate making. As a relief, the convex portion is deformed (so-called low spot), and a clear image cannot be obtained.

Examples of the component (E) photopolymerization initiator include benzophenones, benzoins, acetophenones,
Examples thereof include benzyls, benzoin alkyl ethers, benzyl alkyl ketals, anthraquinones and thioxanthones. Specifically, benzophenone, chlorobenzophenone, benzoin, acetophenone, benzylbenzoin, methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl diisopropyl ketal, anthraquinone, 2-chloroanthraquinone. , Thioxanthone, 2-chlorothioxanthone and the like. These are preferably contained in the composition in an amount of 0.01 to 5% by weight. If it is less than 0.01%, the photopolymerization initiating ability is impaired, and if it is more than 5%, the curing depth cannot be obtained by ordinary light, and the image tends to be chipped due to development, which is not preferable. More preferably, it is 0.1 to 3% by weight.

In order to prevent only thermal polymerization without suppressing the photocrosslinking reaction, 0.001 to 5% by weight of (F) a thermal polymerization inhibitor is contained in addition to the above requirements (A) to (E). Good. Examples of useful thermal polymerization inhibitors include hydroquinone, hydroquinone monoethyl ether, catechol, pt-butylcatechol, 2,6-di-t-butyl-
p-cresol and the like can be mentioned.

As the other plasticizer in the photosensitive resin composition,
Liquid polybutadiene rubber, liquid polyacrylonitrile butadiene rubber, liquid polystyrene butadiene rubber, liquid isoprene rubber, liquid rubber and polyvinyl chloride,
It may contain a relatively low molecular weight elastomer such as chlorinated polyethylene and chlorinated polypropylene, fine powder such as silica and diatomaceous earth.

As a method for producing a printing original plate and a printing plate using the above-mentioned photosensitive resin plate composition, the respective components are subjected to any order in a suitable solvent such as tetrahydrofuran, dioxane, methyl ethyl ketone, toluenecyclohexanone, chloroform. Etc. and water, a hydrophilic polymer such as alcohol is swelled, dispersed and dissolved in a solvent, ie, component (D) under normal conditions, dissolved and mixed, and the solvent is removed, and then a suitable support such as polyester, polyethylene, It can be made by heating and pressing to a film such as polypropylene. A cover film, which is coated with a hydroxyalkyl cellulose coating film containing a plasticizer, which is the composition of the present invention, so as to be a photosensitive resin surface, is pressure-bonded to the surface different from the support to prepare a photosensitive resin laminate.

The ultraviolet ray used for curing the photosensitive resin printing original plate obtained by the above method is 150 to 500 mμ.
Is particularly effective in the wavelength range of 300 to 400 mμ. Light sources used include low pressure mercury lamps, high pressure mercury lamps,
Carbon arc lamp, ultraviolet fluorescent lamp, chemical lamp,
A xenon lamp and a zirconium lamp are preferable.
The photosensitive resin printing original plate is exposed to ultraviolet rays by irradiating a negative film having a transparent image with the above light source to expose the image, and then the non-exposed non-image area is removed with a developing solution at about 25 ° C to 45 ° C. By doing so, the printing plate of the present invention having a clear relief image can be obtained.

The developer includes general domestic water.
Water having a pH of 5.0 to 9.0 is most suitable, and the main component of the water may be an alkaline compound such as sodium hydroxide and sodium carbonate, a surfactant, a water-soluble organic solvent and the like.
As the above surfactant, sodium alkylnaphthalene sulfonate, sodium alkylbenzene sulfonate, etc. are most suitable, and in addition, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants are Can be used.

The developing device used in the present invention is carried out by immersing or spraying the photosensitive resin printing original plate, which has been exposed to the above-mentioned developing solution, in contact with a brush. Upon contact with the developing solution, the anti-adhesion layer comprising the composition of the present invention swells and becomes zey, and is easily removed by brushing, and then the unexposed portion is removed.

The developing solution adhering to the plate after development is washed off with water, and then the adhering water is wiped off and dried. Drying is performed by forced air or infrared rays, but the conditions are not particularly limited. The plate after drying is completely cured by a so-called post-exposure operation in which the plate is further exposed by the light source used for the exposure.

[0040]

EXAMPLES The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. In the examples, "parts" means "parts by weight".

Example 1 Hydroxyethyl cellulose SP40 was added to 4911 parts of pure water.
0 [polymerization degree 843 manufactured by Daicel Chemical Industries, Ltd.] was added, and the mixture was stirred at room temperature for about 1 hour to obtain a transparent aqueous solution.
To this aqueous solution, 9 parts of polyethylene glycol having a molecular weight of 1000 was added with stirring and further stirred for 30 minutes. Next, this aqueous solution was added to a 125 μm polyethylene terephthalate film (E-5000 Toyobo Co., Ltd.) at a speed of 6 m / min.
Product) was coated with a reverse roll and dried at 100 ° C. The tack-preventing layer thus obtained had a thickness of 1.8 μm.

Reference Example 1 A photosensitive resin composition was prepared by the following method.
Hexamethylene diisocyanate 21.8 parts, dimethylol propionic acid 15.4 parts, polytetramethylene glycol (PG-100 Nippon Polyurethane Industry Co., Ltd.)
7.6 parts and a solution of 1.0 part of di-n-butyltin dilaurate dissolved in 300 parts of tetrahydrofuran are placed in a 1 liter flask equipped with a stirrer, and the flask is heated to 65 ° C. for 3 hours while continuing stirring. The reaction continued. In a separate container, a terminal amino group-containing acrylonitrile-butadiene oligomer (Hycar ATBNX 1300 x 1
A solution prepared by dissolving 55.3 parts of 6 Ube Industries, Ltd. in 100 parts of methyl ethyl ketone was added to the above 1 liter flask with stirring at room temperature. The obtained polymer solution was dried under reduced pressure to remove tetrahydrofuran and methyl ethyl ketone to obtain a polymer having a number average molecular weight of 21,000. Next, a solution prepared by dissolving 4.8 parts of lithium hydroxide in 100 parts of methyl alcohol was added to a solution prepared by dissolving 100 parts of the polymer in 100 parts of methyl ethyl ketone at room temperature with stirring, and further stirred for 30 minutes to obtain hydrophilicity. Polymer [I] was obtained.

10 parts of the above hydrophilic polymer [I], 45 parts of chlorinated polyethylene (H-135 manufactured by Osaka Soda Co., Ltd.) as a hydrophobic polymer, styrene-butadiene rubber (manufactured by JSR1507 Nippon Synthetic Rubber Co., Ltd.) 15 Part, butadiene oligoacrylate (PB-A Kyoeisha Yushi Co., Ltd.) 28.5 parts, benzyl dimethyl ketal (Irgacure 651, Ciba Geigy Co., Ltd.) 1 part and hydroquinone monomethyl ether 0.5 part toluene 4
After dissolving and dispersing in 0 part and 10 parts of water and kneading at 105 ° C. using a heating kneader to dissolve and defoam, a photosensitive resin composition was obtained.

This photosensitive resin composition was used in a heat press machine at 105 ° C. and a pressure of 100 Kg / cm ² to obtain 125
Between the polyester film having a thickness of μ and the polyester film having the anti-adhesion layer obtained in Example 1, heat and pressure were applied for 1 minute so that the anti-adhesion layer was in contact with the photosensitive resin, and the thickness was 1.7 mm and 2.8 mm. The sheet (printing original plate) was created. Next, the uppermost polyester film was peeled off and the peeling strength was measured.
It was 5 g / cm for a 2.8 mm sheet of 5 g / cm. When the surface of the anti-adhesion layer on the photosensitive resin was observed, it showed a smooth and mirror-like surface, and there was no adhesion by the tentacle. Further, when the photosensitive resin layer from which the polyester film was peeled off was bent inward and the generation of wrinkles was observed, no wrinkles that would cause a problem were found.

Next, a negative film having an image was closely adhered to the plate obtained in Reference Example 1 and exposed with a mercury lamp (Dainippon Screen Co., Ltd.) at an illuminance of 25 W / m ² for 5 minutes. After removing the negative film, development was performed with a brush in neutral water containing 2% by weight of sodium alkylnaphthalenesulfonate at 40 ° C. for 15 minutes, and an image pattern with a relief (printing plate) depth of 1.2 mm was obtained. Was given. This image pattern faithfully reproduced the image of the negative film used. Further, the obtained relief had good ink transfer property and showed a clear image.

Comparative Example 1 5 parts of Gohsenol GH-17 [polyvinyl alcohol having a saponification degree of 86.5-89 mol% manufactured by Nippon Synthetic Chemical Industry Co., Ltd.] was heated and stirred at 80 ° C. in 94.1 parts of pure water. It was completely dissolved. 0.88 parts of polyethylene glycol having a molecular weight of 1000 was mixed and dissolved in this solution. From this solution, a sticking prevention layer containing 8% of polyethylene glycol having a thickness of 2.5 μ was formed on a polyethylene terephthalate film having a thickness of 125 μ using a wire bar. When the anti-adhesion layer was laminated on the photosensitive resin layer by the method described in Reference Example 1 and the polyethylene terephthalate film as the cover film was peeled off, the 1.7 mm sheet could not be peeled and the 2.8 mm sheet was not peeled off. The peel strength was 30 g / m, and the peeling could not be easily performed. When the polyester film was peeled off, large wrinkles were formed on the surface of the human skin. Also, in the same manner as in Reference Example 1,
Upon development, wrinkles remained on the surface of the photocured image, and ink transfer marks were observed on the printed matter.

Comparative Examples 2 and 3 In Example 1, methyl cellulose and carboxymethyl cellulose were used instead of hydroxyethyl cellulose to prepare an anti-adhesion layer having a thickness of 1.7 μm. Next, a 1.7 mm and 2.8 mm sheet (printing original plate) was prepared in the same manner as in Reference Example 1 except that each of the anti-adhesion layers was used, and the uppermost polyester was peeled off. The surface of the anti-adhesion layer of No. 2 had an adhesive property, and when the polyester film was peeled off, large wrinkles like the surface of the human skin were generated on the surface. When a negative film having an image was brought into close contact with the plate thus obtained, air was trapped in the wrinkled part, and further,
It was difficult to peel the negative film.

Example 2 55 parts of hydroxypropylmethylcellulose E-6 [Nippon Soda Co., Ltd., molecular weight: 30,000 to 40,000] was added to 4897 parts of pure water and stirred at room temperature for about 1 hour to obtain a transparent aqueous solution. To this aqueous solution, 45 parts of hydroxyethyl cellulose SP400 [polymerization degree 843, manufactured by Daicel Chemical Industries, Ltd.] was added, and the mixture was stirred at room temperature for about 1 hour. Furthermore, this aqueous solution has a molecular weight of 100.
3 parts of polyethylene glycol of 0 was added with stirring and stirred for about 30 minutes. Next, this aqueous solution was applied to a 125 μm polyethylene terephthalate film (E-
5000 Toyo Boseki Co., Ltd. product was coated with a reverse roll and dried at 100 ° C. The anti-adhesion layer thus obtained had a thickness of 1.9μ. Next, the photosensitive resin composition obtained in Reference Example 1 was applied between the polyester films having the anti-adhesion layer obtained by the above method in the same manner as in Reference Example 1 to obtain a thickness of 1.7 mm and 2.8 mm. A sheet (printing original plate) was created. Next, the uppermost polyester film was peeled off and the peeling strength was measured to be 1.7 m.
Both the m sheet and the 2.8 mm sheet showed the same measured values as in Reference Example 1 and were easily peeled off. Further, as in Reference Example 2, the tackiness preventive layer on the photosensitive resin had no tackiness and the wrinkles of the photosensitive resin layer were the same in degree, and there was no problem. The anti-adhesion layer obtained in Example 2 was not affected by humidity, and the peelability from the polyester film did not change at all even when it was allowed to stand at 30 ° C. and 80% RH for about 1 month.

Example 3 An anti-adhesion layer was formed in the same manner as in Example 1 except that a polyethylene phthalate film was used as the cover film in Example 1 with a chemical matte film (TC-5000 manufactured by Toyo Cloth Co., Ltd.) having a thickness of 95 μm. Created. The obtained anti-adhesion layer had a thickness of 1.7 μm. Using this coat film, a photosensitive resin laminate was prepared in the same manner as in Reference Example 1, and the chemical mat film was peeled off.
A uniform matte surface was obtained, there were no wrinkles as in Reference Example 1, and the negative flume was easily peeled off.

[0050]

EFFECTS OF THE INVENTION The anti-adhesion layer composition of the present invention contains two or more kinds of hydroxyalkyl cellulose having internal plasticity and excellent flexibility and a plasticizer so that the composition has more flexibility than hydroxyalkyl cellulose and at the same time polyester. When the film (cover film) is peeled off, the peeling force is small, and the peeling force can be easily peeled off with less force. It is preferable that the cover film be peeled off easily in the plate making process, but it is preferable that the cover film is not peeled off easily during the production of the photosensitive resin original plate, the packaging, the transportation and the work of cutting into a desired size. Therefore, the peel strength during plate making is 15 to 2 g /
It is desirable to be within cm, preferably within 10 to 2 g / cm. It was surprising that the release of the hydroxyalkyl cellulose and the plasticizer from the polyester film is effective. Another effect obtained by the anti-adhesion layer composition of the present invention is that the anti-adhesion layer remaining on the photosensitive resin layer when the cover film of the photosensitive resin laminate is peeled off does not cause wrinkles and peels off the cover film. There is something you can do. This facilitates the plate making work and improves the reliability of the printed matter. Furthermore, the anti-adhesion layer composition of the present invention is not affected by humidity or temperature at all, and thus it greatly contributes to the industrial world.

Claims (2)

[Claims] 1. A pressure-sensitive adhesive layer composition for a photosensitive resin printing plate, which comprises hydroxyalkyl cellulose and a plasticizer. 2. The anti-adhesion layer composition for a photosensitive resin printing plate according to claim 1, wherein the hydroxyalkyl cellulose is a mixture of at least two kinds.