JP2940039B2 - Photosensitive resin printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a photosensitive resin printing plate which has rubber elasticity, is water-developable, and has excellent ink resistance. In particular, the present invention is intended for flexographic printing. The present invention relates to a useful photosensitive resin printing plate.

(Prior art) As a conventional photosensitive resin plate for flexographic printing, one developed with an organic solvent is known. However, these printing plates have problems in safety to human body and environment such as toxicity and flammability. Was.

Therefore, a water-based developable photosensitive resin composition has been proposed as an alternative.

For example, a copolymer containing a conjugated diene-based hydrocarbon and an α, β-ethylenically unsaturated carboxylic acid or a salt thereof as essential components, a monooleic unsaturated compound, a photopolymerizable unsaturated monomer, Methods using a photosensitive resin composition containing a sensitizer (JP-A-52-134655, JP-A-53-134655)
No. 10648, JP-A-61-22339), a conjugated diene-based hydrocarbon polymer or a copolymer of a conjugated diene-based hydrocarbon and a monoolefinic unsaturated compound and a hydrophilic polymer compound, a non-gaseous Photosensitive elastomer composition containing an ethylenically unsaturated compound and a photopolymerization initiator as essential components (see JP-A-60-211451), hydrophobic oligomers and elastomers containing α, β-ethylenically unsaturated groups There is a photosensitive resin composition containing a water swellable substance and a photopolymerization initiator as essential components (see JP-A-60-173055).

In addition, for the purpose of improving the performance of the printing plate such as mechanical strength and rebound resilience, a photosensitive resin composition containing hard organic fine particles (see JP-A-63-8648) and an improvement in ink receptivity of the printing plate. For the purpose of having a two-phase structure, a diazo compound,
There is a photosensitive resin composition containing dichromate in a continuous phase and particles having a dispersed phase of 10 μm or less (see Japanese Patent Publication No. 59-36731).

(Problems to be Solved by the Invention) The former in the composition can be developed with an aqueous developer, for example, an alkaline aqueous solution or an alkaline aqueous solution / organic solvent system, but developed with so-called domestic water having a pH of 5.0 to 9.0. And many problems such as insufficient ink resistance of the relief portion.

The latter in the composition must contain a hydrophilic component in the continuous phase in order to enable aqueous development, in which case the content of the hydrophilic component is thermodynamically safe.
It is necessary to increase the content of the dispersed phase forming component. Also in this case, it is difficult to achieve both water developability and ink resistance of the relief portion.

Further, the photosensitive resin composition is basically required to have optical characteristics, that is, light transmittance, and good compatibility between constituent raw materials. Accordingly, since the hydrophilic polymer contained in the composition is inherently high in polarity, it is preferable that the other raw materials to be mixed have high polarity. However, polymers of conjugated diene-based hydrocarbons generally have low polarity, and thus have the disadvantage that the types of hydrophilic polymers having good compatibility and the mixing ratio are limited.

(Means for Solving the Problems) As a result of intensive studies, the present inventors have been able to solve the above-mentioned problems by controlling the phase structure of the photosensitive resin printing plate precursor.

That is, the present invention includes particles in which a phase mainly composed of a hydrophilic polymer exists around a phase mainly composed of a non-crosslinked hydrophobic polymer, a compound containing an ethylenically unsaturated group, and a photopolymerization initiator. This is a photosensitive resin printing original plate.

The particles in the present invention are composed of at least two phases having a phase mainly composed of a hydrophobic polymer and a phase mainly composed of a hydrophilic polymer, and are composed of three or more phases having a plasticizer and the like as necessary. Is also good. As shown in FIG. 1, each phase in the particle has a phase 1 mainly composed of a hydrophobic polymer near the center of the fine particles, and a phase 2 mainly composed of a hydrophilic polymer. It exists around. The content ratio of each phase in the particles may be arbitrary. In each phase in the particle, a hydrophobic polymer is essential in phase 1 and a hydrophilic polymer is essential in phase 2; however, phase 1 may contain a hydrophilic component, and phase 2 may contain a hydrophobic component. May be. Particle size is 0.001μ ~ in terms of resolution and developability
It is several hundred μ, more preferably 0.01 μ to several hundred μ.

The phase structure of the photosensitive resin printing plate precursor in the present invention, when observed by a microscope after dyeing, there is a phase mainly composed of a hydrophobic polymer and a phase mainly composed of a hydrophilic polymer as a dispersed phase, as a continuous phase It turns out that it contains a hydrophobic component and a hydrophilic component. The composition ratio between the dispersed phase and the continuous phase in the present invention is arbitrary.

The photosensitive resin composition for forming the photosensitive resin printing plate precursor of the present invention has a hydrophobic polymer, a hydrophilic polymer, a cross-linking agent and a photoinitiator as essential components. Polymers having a temperature of 5 ° C. or less, including those used as general-purpose elastomers. For example, a polymer obtained by polymerizing a conjugated diene-based hydrocarbon, or a copolymer obtained by polymerizing a conjugated diene-based hydrocarbon and a monoolefin-based unsaturated compound,
A polymer containing no conjugated diene-based hydrocarbon is exemplified.

As the conjugated diene hydrocarbon, 1,3-butadiene, isoprene, chloroprene and the like are used. The conjugated diene-based hydrocarbon may be used alone or as a mixture of two or more.

Monoolefinic unsaturated compounds include styrene,
α-methylstyrene, o-methylstyrene, m-methylstyrene, P-methylstyrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, vinyl acetate, acrylate, methacrylate, etc. Is done.

A polymer obtained by polymerizing a conjugated diene-based hydrocarbon,
Or as a copolymer obtained by polymerizing a conjugated diene-based hydrocarbon and a monoolefin-based unsaturated compound, butadiene polymer, isoprene polymer, chloroprene polymer styrene-butadiene copolymer, styrene-isoprene copolymer, Styrene-chloroprene copolymer, acrylonitrile-butadiene copolymer, acrylonitrile-isoprene copolymer, allylonitrile-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-styrene copolymer Coalescence, acrylonitrile - chloroprene - styrene copolymer, and the like.

Examples of the polymer containing no conjugated diene-based hydrocarbon include an elastomer containing a characteristic amount of chlorine and a non-conjugated diene-based hydrocarbon.

Polymers exhibiting rubber elasticity, having a chlorine content of 50 to 10% by weight, and having a glass transition temperature (hereinafter referred to as Tg) of 5 ° C. or less include polymerization of monomers containing chlorine atoms or containing chlorine atoms. From other monomers that can be copolymerized with the monomer to be copolymerized. It can be obtained by reacting chlorine or an active substance containing chlorine with a polymer not containing a chlorine atom, and specific examples thereof include the following. Epichlorohydrin polymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-propylene oxide copolymer and / or epichlorohydrin rubber which is a copolymer of allyl glycidyl ether [Epichromer manufactured by Osaka Soda Industry Co., Ltd., HYD manufactured by Goodvich Co., Ltd.]
RIN, GECHRON, Zeospan, Hevcule, manufactured by Zeon Corporation
s Co., Ltd. HERCLOR], chlorinated polyethylene [Showa Denko Co., Ltd. Eraslen, Osaka Soda Kogyo Co., Ltd., Dieslac, Hoechst Co., Ltd. HORTALITZ, Dow Chemical
Co., Ltd. DOW CPE], vinyl chloride copolymer, vinylidene chloride, polypropylene chloride, chlorinated ethylene-propylene rubber, and the like.
Two or more types may be used in combination.

The chlorine content of the polymer is 10 to 50% by weight, and if it is out of this range, the flexibility is impaired or the heat stability is deteriorated, and the photosensitive resin composition is too hard or colored. It is not preferable because it becomes easy. Since the conjugated diene-based hydrocarbon polymer containing a chlorine atom or its copolymer contains a carbon unsaturated bond in the main chain, there is a drawback that the chemical stability such as weather resistance is inferior to the case of only a saturated bond. Since the physical properties of the photosensitive resin composition after light irradiation greatly depend on the properties of the hydrophobic component in the present invention, it is preferable that the hydrophobic component is essentially a rubber elastic body. Therefore, its Tg
Must be 5 ° C. or lower, and particularly preferably −10 ° C. or lower.

In the present invention, not only the above-mentioned hydrophobic polymer but also an elastomer having good compatibility and ozone resistance, for example, an acrylic rubber or a polyurethane elastomer may be blended.

The content of the hydrophobic polymer in the entire composition in the present invention is 20 in consideration of physical properties and shape retention as printed matter.
It is preferably at least 30% by weight, and more preferably at most 80% by weight, particularly preferably at most 70% by weight, from the viewpoint of photopolymerizability.

Next, the hydrophilic polymer in the present invention means water or a polymer containing water as a main component and soluble or swelling (dispersing) in a developing solution containing an alkaline aqueous solution, an acidic aqueous solution, an organic solvent, a surfactant or the like. -CO ₂ M group, -SO ₂ M
Groups, (M represents a hydrogen atom, the periodic table I, II, III group element, amine, ammonium), - NH _2, having a hydrophilic group such as -OH, and preferably no crosslinked polymer chain .

Examples of such a hydrophilic polymer include general-purpose resins such as polyvinyl alcohol (PVA) and carboxymethyl cellulose, as well as a diene rubber obtained by copolymerizing (meth) acrylic acid and a diene compound, and a liquid polybutadiene modified with maleic anhydride. And a particularly effective skeleton is -COOM
A polymer having 50 to 50,000 equivalents / 10 ⁶ g of a group (M represents a hydrogen atom, a group I, II, or III element of the periodic table, an amine or ammonium); Examples thereof include alkali metals such as sodium, potassium and lithium, alkaline earth metals such as calcium and magnesium, boron, and aluminum. Incidentally it is difficult to develop in the neutralization water poor affinity for water in -COOM groups less than 50 equivalents / 10 ⁶ g in the present invention, whereas 50,0
If it exceeds 00 equivalents / 10 ⁶ g, it is not preferable because the water-based ink resistance is inferior.

Specific examples of the hydrophilic polymer include -COOM group-containing polyurethane, -COOM group-containing polyurea urethane, -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, sodium polyacrylate, polyvinyl alcohol (PVA), carboxymethyl cellulose (C
MC), hydroxyethylcellulose (HEC), methylcellulose (MC), polyethylene oxide, polyethyleneimine, an outer compound derivative, and the like, but are not limited thereto.

Compounds used to neutralize at least a part of the carboxyl group contained in the hydrophilic polymer include lithium hydroxide, potassium hydroxide, hydroxides of alkali metals such as sodium hydroxide, lithium carbonate, Alkali metal carbonates such as potassium carbonate and sodium carbonate, alkali metal alkoxides such as potassium t-butoxide and sodium methoxide, hydroxides of polyvalent metals such as calcium hydroxide, magnesium hydroxide and aluminum hydroxide, aluminum isopro Polyvalent metal alkoxides such as poxide, triethylamine, tri-n
Tertiary amines such as propylamine, diethylamine,
Secondary amines such as di-n-propylamine, primary amines such as ethylamine and n-propylamine, cyclic amines such as morpholine, N, N-dimethylaminoethyl (meth)
Examples include acrylates, amino group-containing (meth) acrylates such as N, N-diethylaminoethyl (meth) acrylate, ammonium carbonate, and ammonium salts. These may be used alone or in combination.

Further, the hydrophilic polymer may have a polyoxyalkylene chain as a hydrophilic part other than the -COOM group, and may contain an ethylenically unsaturated group so as to act as a crosslinking agent.

In the present invention, in addition to the hydrophilic polymer, for example, a polymer having a hydrophilic group such as a hydroxyl group, an amino group, a sulfonic acid group and / or a polyoxyalkylene chain may be used in combination.

The content of the hydrophilic polymer in the whole composition is preferably 5 to 50% by weight, particularly preferably 7 to 40% by weight, and more preferably 7 to 20% by weight in consideration of aqueous developing property and water-resistant ink property. .

As the compound containing an ethylenically unsaturated group polymerizable by actinic light compounded in the present invention, as a function hydrophobic in addition to the photosensitivity, hydrophilic or hydrophobic,
It may have hydrophilic amphoteric and contain at least one terminal ethylenic group, and this compound is capable of forming a high molecular weight polymer by free radical initiated chain propagation addition polymerization. is there. Suitable ethylenically unsaturated compounds are unsaturated esters of polyols, especially such esters with α-methylene carboxylic acid, such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerol diacrylate, 1 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-hexanediol di (meth) acrylate, trimethylolpropanetri (meth) acrylate diallyl phthalate, fumaric acid diethyl ester, maleic acid dibutyl ester and the like, and N-methylmaleimide, N-ethylmaleimide, N-lauryl Maleimide Which N-substituted maleimide compounds, oligonitrile butadiene di (meth) acrylate, oligonitrile urethane di (meth) acrylate, oligourethane di (meth) acrylate, oligobutadiene di (meth)
Acrylates and oligo (meth) acrylates such as oligobutadiene / urethane (meth) acrylate may be mentioned, and these may be used alone or in combination.

The content of the compound containing an ethylenically unsaturated group in the composition is preferably 1 to 50% by weight, and if it is less than 1% by weight, the photopolymerizability is impaired, and an image does not remain after development.
Conversely, if the content is more than 50% by weight, the shape retention is deteriorated, which is not preferable. Further, the plate after light irradiation is hard and brittle, which is not preferable as a flexographic printing plate material. More preferably, it is 5 to 40% by weight.

The compound containing an ethylenically unsaturated group exists in a continuous phase or a dispersed phase depending on its polarity, ie, hydrophobicity or hydrophilicity.

Next, as the photopolymerization initiator compounded in the present invention, for example, benzophenones, benzoins, acetophenones, benzyls, benzoin alkyl ethers, benzylalkyl ketals, anthraquinones,
Thioxanthones and the like. Specifically, benzophenone, chlorobenzophenone, benzoin, acetophenone, benzyl, benzoin 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 the amount is less than 0.01%, the photopolymerization initiation ability is impaired. If the amount is more than 5%, the curing depth cannot be obtained by the light itself, and the image tends to be chipped by development, which is not preferable. More preferably, it is 0.1 to 3% by weight.

In the present invention, in order to simply prevent thermal polymerization without suppressing the photocrosslinking reaction, a thermal polymerization inhibitor may be contained in an amount of 0.001 to 5% by weight in addition to the composition. Useful thermal polymerization inhibitors include, for example, hydroquinone, hydroquinone monoethyl ether, catechol, pt-
Butyl catechol, 2,6-di-t-phthyl-p-cresol and the like can be mentioned.

In the present invention, as a plasticizer in addition to the composition, liquid polybutadiene rubber, liquid polyacrylonitrile butadiene rubber, liquid polystyrene butadiene rubber, liquid isoprene rubber and the like, liquid rubber, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, , Etc., and fine powders of silica, diatomaceous earth and the like having a relatively low molecular weight.

In the printing plate precursor of the present invention, the method for forming the phase structure as shown in FIG. 1 is not limited. For example, a preferable method is to mix a solvent that swells the hydrophilic component. That is, this is a method in which a solvent that swells and dissolves the hydrophilic polymer but has a small degree of swelling with respect to the hydrophobic polymer is added. Specifically as such a solvent, water, water containing a surfactant, as a surfactant,
Sodium alkyl benzene sulfonate, sodium alkyl naphthalene sulfonate, sodium alkyl ether sulfonate, anionic surfactants including fatty acids, nonionic surfactants, cationic surfactants, lithium hydroxide, potassium hydroxide, hydroxide Water containing salts such as sodium, sodium borate, sodium carbonate, sodium acetate and magnesium acetate, methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, hebutyl alcohol, pentyl alcohol, neo Examples thereof include pentyl alcohol and alcohols containing the salt, and these can be used alone or in combination. Further, solvents which can swell the hydrophilic polymer include esters, ketones and amides. Specifically, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, methyl cellosolve, ethyl cellosolve, acetone,
Solvents such as methyl ethyl ketone, methyl isobutyl ketone formamide, dimethyl formamide, dimethyl acetamide and the like, but are not limited thereto. These solvents can be used alone or in combination.

The phase structure of the photosensitive resin printing original plate, which is a feature of the present invention,
It can be easily obtained by using the solvent for swelling the hydrophilic polymer and the solvent for swelling the hydrophobic polymer in an arbitrary ratio. In addition, as a method of forming a phase structure, fine particles having a structure in the present invention are prepared in advance by means such as emulsion polymerization, melt extrusion, mill blending, etc., and dispersed at the time of preparing the photosensitive resin composition. It is also possible and not limited to these methods.

As a method of preparing the printing original plate of the present invention using the photosensitive resin plate composition, a suitable solvent for the respective components in any order, for example, tetrahydrofuran, dioxane,
A solvent that swells and dissolves hydrophobic pigments such as methyl ethyl ketone, toluene cyclohexanone, and chloroform;
Swells hydrophilic polymers such as water and alcohol,
Dissolve and dissolve in the solvent to be dispersed, remove the solvent by mixing,
It can be prepared by heating and pressing on a suitable support, for example, a film of polyester, polyethylene, polypropylene or the like. A similar film or a film coated or laminated with a thin layer of polyvinyl alcohol, polyacrylamide, hydroxypropyl cellulose or the like soluble in an aqueous developer may be provided on a surface different from the support.

The photosensitive resin printing plate precursor of the present invention obtained by the above method is exposed to ultraviolet light by irradiating a negative film having a transparent image to the image, and then the non-image portion which is not exposed is removed by using a developing solution, whereby a clear image is obtained. A printing plate having an excellent relief image is obtained.

The ultraviolet light used for curing the photosensitive resin printing plate precursor of the present invention is a wavelength of 150 to 500 μm, particularly 300 to 400 μm
The light source used is preferably a low-pressure mercury lamp, high-pressure mercury lamp, carbon arc lamp, ultraviolet fluorescent lamp, chemical lamp, xenon lamp, or zirconium lamp.

Further, as the developer, pH 5.0 containing water for daily use in general
Water of from 9.0 to 9.0 is optimal, and may contain an alkaline compound such as sodium hydroxide and sodium carbonate, a surfactant, and a water-soluble organic solvent as the main component of the water. As the above-mentioned surfactant, sodium alkylnaphthalenesulfonate, sodium alkylbenzenesulfonate and the like are most suitable, and in addition, anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants are preferable. Can be used.

 The developer is preferably used at a temperature of 25 ° C to 45 ° C.

The relief plate obtained from the photosensitive resin printing plate precursor of the present invention has rubber elasticity and is useful as a flexographic printing plate. In addition, it has excellent ink resistance, especially water-based ink resistance, ink transfer properties, and printing durability. The photosensitive resin composition used in the present invention is mainly useful as a flexographic printing plate,
It can also be used for photoresists and sandblasts, and can also be used as elastomers that are cured by ultraviolet rays, such as adhesives, films, paints, and the like.

(Operation) One of the features of the present invention is that a layer having a hydrophobic polymer as a main component, a particle having a phase mainly containing a hydrophilic polymer as a dispersed phase, and a phase having a hydrophilic component and a hydrophobic component are used. Is a continuous phase. During development, the continuous phase and the phase mainly composed of the hydrophilic polymer in the dispersed particles undergo water absorption swelling and dispersion, and the phase mainly composed of the hydrophobic polymer in the dispersed phase is dispersed. According to this mechanism, water development is possible even when the content of the hydrophobic polymer is increased and the content of the hydrophilic polymer is reduced, and therefore the content of the hydrophilic component can be reduced. Is expected to be improved.

(Examples) Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

 In the examples, “parts” means “parts by weight”.

The hardness, rebound resilience and phase structure of the printing plate precursor of the present invention were confirmed by the following methods.

Hardness: Measured at 20 ° C by a spring hardness test (A type) according to JIS-K6301.

Rebound resilience: 20 steel balls of φ10m / m (weight 4.16g)
The height (a), which was dropped from the height of the cm ground and bounced back, was read and displayed as (a / 20) × 100%.

Confirmation of phase structure: The obtained printing plate was immersed in a 1.0% aqueous solution of primocyanin (crystal violet) at 25 ° C. for 30 minutes, whereby the hydrophilic polymer was selectively dyed, and a cryomicrotome (Reichert Ultracut N) was used. so
A 200 × 200 μm section was prepared and observed with a reflection microscope.

Example 1 21.8 parts of hexamethylene diisocyanate, 15.4 parts of dimethylolpropionic acid, 7.6 parts of polytetramethylene glycol (PG-100, manufactured by Nippon Polyurethane Industry Co., Ltd.), and 1.0 part of di-n-butyltin dilaurate in 300 parts of tetrahydrolaran The solution dissolved in
The flask was placed in a flask, and the flask was heated to 65 ° C. while stirring, and the reaction was continued for 3 hours. In a separate container, acrylonitrile-butadiene oligomer containing terminal amino units (Hycar AT
A solution prepared by dissolving 55.3 parts of BNB.X 1300 × 16 (produced by Ube Industries, Ltd.) in 100 parts of methyl ethyl ketone was added to the above one flask while 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, 100 parts of the polymer was methyl ethyl ketone 1
A solution in which 4.8 parts of lithium hydroxide was dissolved in 100 parts of methyl alcohol was added to the solution dissolved in 00 parts with stirring at room temperature, and the mixture was further stirred for 30 minutes to obtain a hydrophilic polymer [I].

10 parts of the above hydrophilic polymer [I] and chlorinated polyethylene (H-135 Osaka Soda Co., Ltd.) as the hydrophobic polymer
45 parts, styrene-butadiene rubber (SBR 1507 manufactured by Nippon Synthetic Rubber Co., Ltd.) 15 parts, butadiene oligoacrylate (PB-A Kyoeisha Yushi Co., Ltd.) 28.5 parts, benzyldimethyl ketanol (Irgacure 651, Ciba Geigy Co., Ltd.)
1 part) and hydroquinone monomethyl ether 0.5
Toluene 40 parts, dissolved in water 10 parts, dispersed, kneaded at 105 ° C. using a heating kneader and defoamed, the resulting photosensitive resin composition at 105 ° C., 100 kg / cm ^{3 in} a heat press machine Pressure is applied between the polyester film of 125μ thickness and the polyester film of 2μm polyvinyl alcohol coated on one side on the same polyester film for 1 minute so that the polyvinyl alcohol coat layer is in contact with the photosensitive resin, and the thickness is 2.8mm. Sheet (print original plate) was created.

The obtained printing original plate was immersed in a 1.0% aqueous solution of primocyanin (crystal violet) at 25 ° C. for 30 minutes,
Cryomicrotome (Reichert Ultra Cut N)
To prepare a 200 × 200 × 200 μm section, and observed with a reflection microscope. As a result, it was found that the polymer [I] was selectively dyed and existed around each dispersed particle.

Next, the polyester film of the uppermost layer is peeled off to leave a polyvinyl alcohol film on the photosensitive resin layer, and a negative film having an image is adhered thereon, and an illuminance of 25 W / m ^{2 is applied} by a mercury lamp (manufactured by Dainippon Screen Co., Ltd.). Roots were exposed for 5 minutes.
After removing the negative film, development was carried out with a brush at 40 ° C. for 15 minutes in neutral water containing 2% by weight of sodium alkylnaltarenesulfonate. As a result, an image pattern having a relief depth of 1.2 mm was obtained. This image pattern faithfully reproduced the image of the negative film used. Further, the obtained relief had a good transferability of the ink and showed a clear image.

Example 2 A relief pattern was obtained in the same manner as in Example 1 except that 4.56 parts of sodium hydroxide was used instead of 4.8 parts of lithium hydroxide in the hydrophilic polymer [I] of Example 1, and an image of a negative film was obtained. Was faithfully reproduced, and a relief having excellent ink transferability was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 3 A relief pattern was obtained in the same manner as in Example 1 except that 17.9 parts of N, N-dimethylethyl methacrylate was used in place of 4.8 parts of lithium hydroxide in the hydrophilic polymer [I] of Example 1. The image of the negative film was faithfully reproduced, and a relief excellent in ink transferability was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 4 A relief pattern was obtained in the same manner as in Example 1, except that 2.4 parts of lithium hydroxide and 6.1 parts of magnesium acetate were used instead of 4.8 parts of lithium hydroxide in the hydrophilic polymer [I] of Example 1. As a result, an image of the negative film was faithfully reproduced, and a relief excellent in ink receiving transferability was obtained.

Example 5 A relief pattern was obtained in the same manner as in Example 1 except that the hydrophilic polymer [I] was replaced by a polyisoprene containing sodium chloride and carboxyl group (Kuraprene LIR-840, manufactured by K.K.). As a result, the image of the negative film was faithfully reproduced, and a relief excellent in ink receiving transferability was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 6 A relief pattern was prepared in the same manner as in Example 1 except that in place of the hydrophilic polymer [I], a nitrile-butadiene rubber containing sodium chloride and a carboxyl group (sodium chloride NIPOL 1072 manufactured by Zeon Corporation) was used. As a result, a negative film image was faithfully reproduced, and a relief excellent in ink receiving transferability was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 7 A relief pattern was formed in the same manner as in Example 1 except that styrene butadiene having a sodium chloride carboxyl group (SW-307 manufactured by Sumitomo Nogatack Co., Ltd.) was used instead of the hydrophilic biopolymer [I]. As a result, the image of the negative film was faithfully reproduced, and a relief having excellent ink transferability was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 8 In Example 1, epichlorohydrin rubber (Epichromer H Osaka Soda Co., Ltd.) was used instead of chlorinated polyethylene.
When a relief pattern was obtained in the same manner as in Example 1 except that the negative pattern was used, an image of a negative film was faithfully reproduced, and a relief having excellent ink transferability was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 9 A relief pattern was obtained in the same manner as in Example 1 except that a styrene-butadiene-styrene block copolymer (Kraton 1101 (trade name) manufactured by Shell Petrochemical Co., Ltd.) was used in place of chlorinated polyethylene. As a result, a negative film image was faithfully reproduced, and a relief having excellent ink transferability was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 10 In Example 1, 7.5 parts of hydrophilic polymer [I], 47.5 parts of chlorinated polyethylene (H-135 manufactured by Osaka Soda Co., Ltd.)
Parts, styrene-butadiene rubber (SBR 1507, Nippon Rubber Co., Ltd.) 15 parts, butadiene oligoacrylate (PB-
A Using 28.5 parts of Kyoeisha Yushi Co., Ltd., 1 part of benzyl dimethyl ketal (Irgacure 651 Ciba Geigy Co., Ltd.) and 0.5 part of hydroquinone monomethyl-ether, a relief pattern was obtained in the same manner as in Example 1 to obtain a negative film. Was faithfully reproduced, and a relief excellent in ink receiving transferability was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 11 A relief pattern was obtained in the same manner as in Example 1 except that methyl alcohol was used instead of water as the solvent in Example 1. The image of the negative film was faithfully reproduced, and the ink transferability was excellent. A relief was obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Example 12 In Example 4, a relief pattern was obtained in the same manner as in Example 4 except that methyl alcohol was used instead of water. When the relief pattern was faithfully reproduced, the relief of the negative film was excellent. Obtained.

When stained with crystal violet and observed under a microscope in the same manner as in Example 1, the same phase structure as in Example 1 was observed.

Reference Example Table 1 shows the developing speed, hardness and rebound resilience of the reliefs obtained in Examples 1 to 12.

(Effects of the Invention) Since the printing plate precursor of the present invention having the above-mentioned constitution has sufficient rubber elasticity, is capable of developing with water, and has contradictory properties such as water-resistant ink property, it is indispensable for industry and environmental hygiene. It is great to contribute to such things.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state of a section of the printing original plate of the present invention observed at a magnification of about 200 times with a microscope, wherein 1 is a phase mainly composed of a hydrophobic polymer, and 2 is a phase mainly composed of a hydrophilic biopolymer. Shows the phases as components.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-219833 (JP, A) JP-A-3-196604 (JP, A) JP-A-1-108512 (JP, A) JP-A-1- 300246 (JP, A) JP-A-63-186232 (JP, A) JP-A-2-175702 (JP, A) JP-A-3-1366052 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03F 7/00, 7/004

Claims (1)

(57) [Claims] 1. A particle comprising a phase mainly composed of a hydrophilic polymer around a phase mainly composed of a non-crosslinked hydrophobic polymer, a compound containing an ethylenically unsaturated group and a photopolymerization initiator. An original photosensitive resin printing plate, characterized in that: