JPH03171139A - Photosensitive resin printing plate - Google Patents

Abstract

PURPOSE:To obtain the resin printing plate which has rubber elasticity, allows aq. development and has excellent ink resistance by incorporating the flocks of microparticles having a phase essentially consisting of a hydrophobic polymer and a phase essentially consisting of a hydrophilic polymer. CONSTITUTION:The microparticles are constituted of at least the two phases; the phase essentially consisting of the hydrophobic polymer and the phase essentially consisting of the hydrophilic polymer. For example, the phase 1 essentially consisting of the hydrophobic polymer exists preferably near the center of the microparticles and the phase 2 essentially consisting of the hydrophilic polymer exists around the phase 1. The grain sizes of the microparticles are preferably 0.001 to 100mu and the grain sizes of the particles obtd. by flocculation of the microparticles are 0.01mu to several 100mu, in terms of definition and developability. Thus, the printing plate has the contracting properties of the sufficient rubber plasticity, the feasibility of the water development and the ink resistance.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a photosensitive resin printing plate that has rubber elasticity, is capable of water-based processing, and has excellent ink resistance. Concerning useful photosensitive resin printing plates. (Prior art) Conventional photosensitive resin plates for flexographic printing are known to be sensitive to aqueous solvents, but these printing plates have safety issues for the human body and the environment, such as toxicity and flammability. there were. Therefore, as an alternative to this, a photosensitive resin sole that is capable of water-based phenomena has been proposed. For example, a copolymer containing a conjugated diene hydrocarbon and an α,β monoethylenically unsaturated carboxylic acid or a salt thereof as an essential ingredient, and a monoolefinically unsaturated compound, and a photopolymerizable unsaturated monomer. , a method using a photosensitive resin composition containing a photosensitizer (JP-A-52-134655, JP-A-53-1064)
No. 8, No. 61-22339), a conjugated diene hydrocarbon polymer or a copolymer of a conjugated diene hydrocarbon and a monoolefinic unsaturated compound, a hydrophilic polymer compound, a non-gaseous A photosensitive elastomer containing an ethylenically unsaturated compound and a photopolymerization initiator as essential ingredients? -AIltc product (see Japanese Patent Application Laid-Open No. 60-211451)
, a hydrophobic oligomer containing α, β monoethylenically unsaturated groups, an elastomer water-swellable substance and a photopolymerization initiator as essential ingredients (JP-A-1988-1999)
(See Publication No. 173055). In addition, for the purpose of improving the mechanical strength, rebound resilience, and other performance of printing plates, photosensitive resin compositions containing hard organic particles (see Japanese Patent Application Laid-open No. 1986-8648) are used to improve the ink receptivity of printing plates. A photosensitive resin composition having a two-phase structure with the purpose of
(See Publication No. 31).

(Problem B to be Solved by the Invention) The former composition can be developed with an aqueous developer, such as an alkaline aqueous solution, or an alkaline aqueous solution/organic solvent system, but the so-called daily life developer with a pH of 5.0 to 9.0 It has many problems, such as the phenomenon that occurs due to water use, and the ink resistance of the relief part is not sufficient. In addition, in the latter case in the above & Due to its properties, it is necessary to increase the content by a certain amount to form a dispersed phase. In this case as well, it is difficult to achieve both water developability and ink resistance of the relief portion.

Furthermore, as a photosensitive resin composition, its optical properties, that is, light transmittance, are fundamental, and good compatibility between the raw materials is required. Therefore, since most of the hydrophilic polymers contained in Kumikaimono are naturally highly polar, it is preferable that the other raw materials to be mixed with them also have high polarity. However, since conjugated diene hydrocarbon polymers generally have low polarity, they have the disadvantage that the types of hydrophilic polymers with good compatibility and the mixing ratio are limited.

(Means for Solving the Problem) As a result of intensive studies, the present inventors were able to solve the above problem by controlling the phase structure of the photosensitive resin layer in the photosensitive resin printing plate.

That is, the present invention is a photosensitive resin printing plate characterized by containing an aggregate of microparticles having a phase mainly composed of a hydrophobic polymer and a phase mainly composed of a hydrophilic polymer.

The microparticles in the present invention are composed of at least two phases including a phase mainly composed of a hydrophobic polymer and a phase mainly composed of a hydrophilic polymer, and optionally composed of three or more phases containing a plasticizer etc. You may be disciplined. The structure of each phase within the particle may be arbitrary, but as shown in Figure 1, phase 1, which has a hydrophobic polymer as its main component, exists near the center of the microparticle, and a hydrophilic polymer as its main component. It is preferable that phase 2 exists around phase 1. The content ratio of each phase within the particle may be arbitrary. Each phase in the particle is a hydrophobic polymer in phase 1, a hydrophilic polymer in phase 2, but phase 1 may contain a hydrophilic component, and phase 2 contains a hydrophobic component. You may. The particle size may be arbitrary, but from the viewpoint of resolution and developability, the particle size of microparticles is 0.001.
The particle diameter of the particles obtained by agglomerating the microparticles is preferably 0.01 μ to several 100 μ. When observed under a microscope, the phase structure of the photosensitive resin printing plate of the present invention shows that the above-mentioned aggregated particles form a dispersed phase, and when dyed, a phase containing a hydrophobic polymer and a hydrophilic polymer exists, and a continuous phase is formed. It can be seen that it contains hydrophobic and hydrophilic components as phases. Note that the composition ratio of the dispersed phase and continuous phase in the present invention is arbitrary.

The photosensitive resin composition that forms the photosensitive resin layer of the photosensitive resin printing plate of the present invention includes a hydrophobic polymer, a hydrophilic polymer, a crosslinking agent, and a photoinitiator as essential components, and first, preferred hydrophobic polymers are used. has a glass transition temperature of 5°C
The following polymers include those used as general-purpose elastomers. Examples include polymers obtained by polymerizing conjugated diene hydrocarbons, copolymers obtained by polymerizing conjugated diene hydrocarbons and monoolefinic unsaturated compounds, and polymers containing no conjugated diene hydrocarbons. It will be done.

As the conjugated diene hydrocarbon, 1,3-ptadiene, isobrene, chloroprene, etc. are used. The conjugated diene hydrocarbons may be used alone or in combination of two or more.

Examples of monoolefinically unsaturated compounds include styrene, α
-Methylstyrene, 0-methylstyrene, m-methylstyrene, P-methylstyrene, acrylic nitrile, methacrylic nitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, vinyl acetate, acrylic ester, methacrylic ester etc. are used. A polymer obtained by polymerizing a conjugated diene-based hydrocarbon,
Or copolymers obtained by polymerizing conjugated diene-based hydrocarbons and monoolefin-based unsaturated compounds include butadiene polymers, isoprene polymers, chloroprene polymers, styrene-butane diene copolymers, styrene-isoprene copolymers. Copolymer, styrene-chloroprene copolymer, acrylonitrile-butadiene copolymer, acrylonitrile-isoprene copolymer, acrylonitrile-chloroprene copolymer, methylbutadiene methacrylate copolymer, methyl methacrylate-isoprene copolymer , methyl methacrylate-chloroprene copolymer, methyl acrylate-butadiene copolymer, methyl acrylate-isoprene copolymer, methyl acrylate-chloroprene copolymer, acrylonitrile-cyclodiene-styrene copolymer, acrylonitrile-ru-styrene copolymer Examples include copolymers, acrylonitrile-chloroprene-styrene copolymers, and the like. Examples of polymers that do not contain conjugated diene hydrocarbons include elastomer-free nonconjugated diene hydrocarbons that contain a specific amount of chlorine. Polymers that exhibit rubber elasticity, have a chlorine content of 50 to 10% by weight, and a glass transition temperature (hereinafter referred to as Tg) of 5°C or less include polymerization of monomers containing chlorine atoms, or polymers containing chlorine atoms. It is obtained by copolymerizing the monomers it contains with other monomers that can be copolymerized. Note that it can also be obtained by reacting chlorine or an active substance containing chlorine with a polymer that does not contain a chlorine atom, and specifically, the following can be mentioned. shrimp chlorohydrin polymer,
Shrimp chlorohydrin-ethylene oxide copolymer, shrimp chlorohydrin-propylene oxide copolymer, and
Or shrimp chlorohydrin rubber, which is a copolymer of these and allyl glycidyl ether [Epichromer manufactured by Osaka Soda Kogyo ■, HY manufactured by Goodvichll [1RTN,
GECIIRON Zeospan, He made by Nippon Zeon ■
} IERCLOR manufactured by vcules ■, chlorinated polyethylene [Elaslen manufactured by Showa Denko ■, Daisolac manufactured by Osaka Soda Kogyo ■, 11011T manufactured by Hoechs ■
ALITZ, DOW made by Low Chemical■
CPE), vinyl chloride copolymer, vinylidene chloride,
Examples include chlorinated polypropylene and chlorinated ethylene-propylene rubber, and these polymers may be used alone or in combination of two or more. The chlorine content of the polymer is 10 to 50% by weight; if it is out of this range, its flexibility may be impaired, its thermal stability may deteriorate, the photosensitive resin composition may be too hard, or it may become discolored. This is not preferable because it makes it easier to do so. Conjugated diene hydrocarbon polymers containing chlorine atoms or their copolymers contain carbon unsaturated bonds in their main chains, so they have the disadvantage that chemical stability such as weather resistance is inferior to those containing only saturated bonds. Furthermore, since the physical properties of the photosensitive resin composition after irradiation with light largely 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 needs to be 5°C or less, particularly preferably 110"C or less. In the present invention, not only the hydrophobic polymer but also an elastomer having good compatibility with the hydrophobic polymer and having ozone resistance, such as Acrylic rubber, polyurethane elastomer, etc. may be blended.The content of the hydrophobic polymer in the total composition in the present invention is 20% by weight or more, especially considering the physical properties and shape retention of the printing plate. It is preferably 30% by weight or more, and from the viewpoint of photopolymerizability, it is preferably 80% by weight or less, particularly 70% by weight or less.

Next, the hydrophilic polymer in the present invention refers to a polymer that is soluble or swells (dispersed) in water, an alkaline aqueous solution containing water as a main component, an acidic aqueous solution, an organic solvent, or a developer containing a surfactant.・Means, =COzM group, -
! li03M group, (M is hydrogen atom, periodic table I, ■, ■
(indicates group elements, amines, ammonium), NHHz,
Polymers that have a hydrophilic group such as OR, are chain-like, and have no crosslinks are preferred. Examples of such hydrophilic polymers include polyvinyl alcohol (PVA), general-purpose resins such as carboxymethyl cellulose, diene rubber made by copolymerizing (meth)acrylic acid and a diene compound, and liquid polyptadiene modified with maleic anhydride. Also, as a particularly effective skeleton, a polymer having 50 to 50,000 equivalents/10'g of -COOM group (M is a hydrogen atom, a group I, ■, ■, group element of the periodic table, agon, ammonium) Examples of the elements of groups 1 and 2 of the periodic table include alkali metals such as sodium, potassium, and lithium, alkaline earth metals such as calcium and magnesium, boron, and argonium. Note that in the present invention -CO
If the OM group is less than 50 equivalents/10'g, the affinity for water is poor and it is difficult to develop with neutral water;
If it exceeds o equivalent/io'g, the water resistance of the ink will be poor, which is not preferable.

Specifically, the hydrophilic polymers include -COOM group-containing polyurethane, -COOM group-containing polyurea urethane, -C
OOM group-containing polyester, -COOM group-containing epoxy compound, -COOM group-containing polyamic acid, COOM group-containing acrylonitrile-butadiene copolymer -COO
M & containing styrene-butadiene copolymer, -CO
OM group-containing polyptadiene, polyacrylamide, sodium polyacrylate, polyvinyl alcohol (PVA
), carboxymethylcellulose (C?IC),
Hydroxyethylcellulose (IIEc), methylcellulose (MC), polyethylene oxide, polyethyleneimine, and derivatives of these compounds can be used, but
It is not limited to these.

The compounds used to neutralize at least a portion of the carboxyl groups contained in the hydrophilic polymer include hydroxides of alkali metals such as lithium hydroxide, potassium hydroxide, and sodium hydroxide, and lithium carbonate. , alkali metal carbonates such as potassium carbonate and sodium carbonate, alkali metal alkoxides such as potassium t-butoxide and sodium methoxide, polyvalent metal hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide, and aluminum. Polyvalent metal alkoxides including isopoxides, tertiary amines such as triethylamine and tri-n-propylamine, secondary amines such as diethylamine and di-n-propylamine, ethylamine,
Primary amines such as n-probylamine, cyclic amines such as morpholine, amino group-containing (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, Examples include ammonium carbonate salts and ammonium salts. These may be used alone or in combination.

Further, the hydrophilic polymer may have a polyoxyalkylene chain as a hydrophilic moiety in addition to the one COOM group, and may also contain an ethylenically unsaturated group so as to act as a crosslinking agent. Furthermore, in the present invention, in addition to the hydrophilic polymer, for example,
Hydrophilic groups such as hydroxyl groups, amino groups, sulfonic acid groups and/or
Alternatively, a polymer having a boroxyalkylene chain may be used in combination.

In addition, all of the hydrophilic polymers &lIfi. The content in the substance is
In consideration of water-based phenomenon properties and water-based ink resistance, it is preferably 5 to 50% by weight, particularly 7 to 40% by weight, and more preferably 7 to 20% by weight.
% by weight is preferred.

Examples of the crosslinking agent used in the present invention include compounds containing an ethylenically unsaturated group that can be polymerized by actinic rays. The compound may contain at least one terminal ethylenic group and is capable of forming a high molecular weight polymer by free radical initiated chain growth addition polymerization. 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-hexanediol di(mec)acrylate, trimethylolbroban tri(meth)acrylate diallyl phthalate, fumaric acid diethyl ester, maleic acid dibutyl ester, etc.; N-substituted maleimide compounds such as ethylmaleido, N-laurylmaleimide, oligonitrile butadiene di(meth)
Acrylate, oligonitrile urethane (meth)acrylate, oligourethane di(meth)acrylate, oligobutadiene di(meth)acrylate, oligoptadiene urethane di(meth)acrylate, etc.
Examples include meth)acrylates, which may be used alone or in combination. The content of the compound containing an ethylenically unsaturated group in the bottom is preferably from I to 50% by weight, and if it is less than 1% by weight, photopolymerizability will be impaired and no image will remain after development.
On the other hand, if it exceeds 50% by weight, shape retention becomes poor, which is not preferable. In addition, the plate becomes hard after being irradiated with light, causing it to bend.
Not suitable as a material for flexo printing plates. More preferably, it is 5 to 40% by weight. Compounds containing ethylenically unsaturated groups exist in a continuous phase or a dispersed phase depending on their polarity, ie, hydrophobicity or hydrophilicity. Next, the photopolymerization initiator blended in the present invention is as follows:
Examples include benzophenones, benzoins, acetophenones, benzyls, penzoin alkyl ethers, penzyl alkyl kekuls, anthraquinones, thioxanthones, and the like. Specifically, penzophenone, chlorobenzophenone, benzoin, acetophenone, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether,
Examples include penzoin isobutyl ether, benzyl dimethyl ketal, benzyl diethyl ketal, penzyl diisopropyl ketal, anthraquinone, 2-chloroanthraquinone, thioxanthone, 2-chlorothioxanthone. These are preferably contained in the composition in an amount of 0.01 to 5% by weight. 0. If it is less than Ol%, the ability to initiate photopolymerization will be impaired, and if it is more than 5%, it will not be possible to obtain a curing depth due to the general light, and the image will be likely to be chipped during development, which is not preferable. More preferably 0.1 to 3%
It is. In the present invention, in order to simply prevent thermal polymerization without suppressing the photocrosslinking reaction, 0.001 to 5% by weight of a thermal polymerization inhibitor may be contained in addition to the above-mentioned composite sole. Useful thermal polymerization inhibitors include, for example, hydroquinone, hydroquinone monoethyl ether, catechol, p-t
-butylcatechol, 2,6-di-t-phthyl-p-cresol, and the like. In the present invention, in addition to the above-mentioned composite sole, as a plasticizer, liquid rubber such as liquid polybutadiene rubber, liquid polyacrylonitrile butadiene rubber, liquid polystyrene butadiene rubber, liquid isoprene rubber, polyvinyl chloride,
It can contain relatively low molecular weight elastomers such as chlorinated polyethylene and chlorinated polypropylene, and fine powders such as silica and silica.

In the printing plate of the present invention, the method for forming the phase structure shown in FIG. 1 is not limited, but a preferred method is, for example, to include a solvent that swells the hydrophilic components. That is, this is a method of blending a solvent that swells and dissolves a hydrophilic polymer, but has a low swelling degree for a hydrophobic polymer. Specifically, such solvents include water, water containing a surfactant, surfactants such as sodium alkylbenzene sulfonate, sodium alkylnaphthalene sulfonate, sodium alkyl ether sulfonate, and anionic interfaces such as fatty acids. Activators, nonionic surfactants, cationic surfactants, water containing salts including lithium hydroxide, potassium hydroxide, sodium hydroxide, sodium borate, sodium carbonate, sodium acetate, magnesium acetate, methyl Examples include alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, hebutyl alcohol, pentyl alcohol, neopentyl alcohol, and alcohols containing the above salts, which may be used alone or in combination. It can be used as Further examples include ester, ketone, and amide solvents as long as they swell hydrophilic polymers. Specifically, solvents include ethyl acetate, probyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, methyl isobutyl ketone formamide, dimethyl formamide, dimethyl acetamide, etc. It is not limited. These solvents can be used alone or in combination.
The phase structure in the photosensitive resin layer of the photosensitive resin printing plate, which is a feature of the present invention, can be easily achieved by using the above-mentioned solvent that swells the hydrophilic polymer and solvent that swells the hydrophobic polymer in an arbitrary ratio. You can get it. In addition, as a method for shaping the phase structure, fine particles having the structure of the present invention are prepared in advance by means such as emulsion polymerization, melt extrusion, mill blending, etc., and dispersed during preparation of the photosensitive resin composition. However, the method is not limited to these methods.

In the present invention, first, the printing original plate is prepared by swelling and dissolving the above-mentioned components in a suitable solvent such as tetrahydrofuran, dioxane, methyl ethyl ketone, toluene cyclohexanone, chloroform, etc. in an arbitrary order. Solvent and water, alcohol, and other hydrophilic polymers are swollen, melted, and dispersed. Dissolved and mixed in a solvent, removed the solvent, and heated and pressed onto a suitable support, such as a film such as polyester, polyethylene, or polypropylene. By doing so, you can create power. Further, a film coated or laminated with a thin layer of polyvinyl alcohol, polyacrylamide, hydroxybutylene cellulose, etc. soluble in an aqueous developer may be provided on a surface different from the support.

The ultraviolet rays used to cure the photosensitive resin printing original plate of the present invention obtained by the above method are 150 to 500 mμ.
, particularly those in the wavelength range of 300 to 400 mμ are effective, and the light sources used are preferably low pressure mercury lamps, high pressure mercury lamps, carpon puke lamps, ultraviolet fluorescent lamps, chemical lamp xenon lamps, and zirconium lamps.

The printing plate of the present invention is prepared by applying a negative film having a transparent image to the photosensitive resin printing original plate using the light source, irradiating it with ultraviolet rays to expose the image, and then removing the unexposed non-image area using a developer. obtained by

The developing solution is pl+5.0 containing general household water.
~9.0 water is optimal, and with this water as the main ingredient, alkaline compounds such as sodium hydroxide and sodium carbonate,
Surfactant, water-soluble m. It may also contain a solvent or the like.

As the above-mentioned surfactant, sodium alkylnaphthalene sulfonate, sodium alkylbenzene sulfonate, etc. are most suitable, and anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants are also suitable. Can be used.

Note that the developer is preferably used at a temperature of 25°C to 45°C.

The photosensitive resin printing plate of the present invention has rubber elasticity and is useful as a flexographic printing plate. It also has excellent ink resistance, especially water-based ink resistance, ink transferability, and printing durability. The photosensitive resin composition used in the present invention is mainly useful as a flexo printing plate, but it can also be used for photoresists and sandplasts, and can also be used as an elastomer that is cured by ultraviolet rays, such as adhesives, It can also be used for films, paints, and more.

(Function) One of the features of the present invention is that the photosensitive resin layer uses aggregates of microparticles having a phase mainly composed of a hydrophobic polymer and a phase mainly composed of a hydrophilic polymer as a dispersed phase. One example of this is that it has a phase structure in which a phase containing a hydrophobic component and a hydrophobic component is a continuous phase. During development, the phase mainly composed of a hydrophilic polymer in the particles of the continuous phase and the separated phase absorbs water and swells and disperses, thereby dispersing the phase mainly composed of a hydrophobic polymer in the dispersed phase. According to this mechanism, water development is possible even if the content of the hydrophobic polymer is increased and the content of the hydrophilic polymer is decreased. Therefore, the content of the hydrophilic component can be reduced, so the water-resistant ink in the relief area is It is expected that this will improve. (Examples) The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. In the examples, parts mean parts by weight.

In addition, the hardness, rebound resilience, and phase structure of the printing plate of the present invention
1 iW was measured by the following method.

Hardness: Measured at 20°C using the spring type hardness test (Type A) method according to JIS-κ6301. Resilience modulus: A steel ball of φlo+w/m (weight 4.16 g) was dropped from a height of 20c+i ground, the height of rebound (a) was read, and expressed as (a/20) x 100%. Confirmation of phase structure: By immersing the obtained printing plate in a 1.0% aqueous solution of brimocyanine (crystal violet) for 30 minutes at 25°C, the woody polymer was selectively dyed and dyed using a cryo-ξ chromatome (Reichert). A 2 μm section was prepared using Ultracut N) and observed using a reflective W4 microscope.

Example 1 21.8 parts of hexamethylene diisocyanate, 15.4 parts of dimethylolpropionic acid, polytetramethylene glycol (PG-100 manufactured by Nippon Polyurethane Industry ■)
7.6 parts, and 1. di-n-butyltin dilaurate.
II. ．． The mixture 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 acrylic acid groups (tlycarATBNBNX 1300
A solution prepared by dissolving 55.3 parts of X16 (manufactured by Ube Industries, Ltd.) in 100 parts of methyl ethyl ketone was added to the above-mentioned lffi flask at room temperature with stirring. The obtained polymer solution was dried under reduced pressure to remove tetrahydrofuran and methyl ethyl ketone, and the number average molecular weight was 21. 00
0 polymer was obtained. Next, a solution of 4.8 parts of lithium hydroxide dissolved in 100 parts of methyl alcohol was added to a solution of 100 parts of the polymer dissolved in 100 parts of methyl ethyl ketone at room temperature with stirring, and the mixture was further stirred for 30 minutes. Polymer (1) was obtained. 10 parts of the above wood-philic polymer [1], 45 parts of chlorinated polyethylene (H-135 Dai [manufactured by Soda ■) as a hydrophobic polymer, styrene-butadiene rubber (SBR)
1507 Japan Gokai Rubber Co., Ltd.) 15 parts, butadiene oligoacrylate (PB-A Kyoeisha Oil ■) 28.5
part, penzyl dimethyl ketanol (Irgacure 651
1 part of Ciba-Geigi Co., Ltd.) and 0.5 part of hydroquinone monomethyl ether were dissolved and dispersed in 40 parts of toluene and 10 parts of water, and the mixture was kneaded at 105°C using a heating machine to defoam, and the resulting photosensitive material The resin composition was heated to 125°C using a heat press machine at 105°C and a pressure of 100 kg/aj.
Heat and press for 1 minute between a polyester film with a thickness of 1μ and a polyester film coated with 2μ of polyvinyl J Leanorecol on one side on the same polyester vinyl film so that the polyvinyl alcohol coating layer is in contact with the photosensitive resin. 2.8 tm thick sheet (printing original plate)
was created.

Next, the uppermost polyester film was peeled off to leave a polyvinyl alcohol film on the photosensitive resin layer, and a negative film with an image pattern was placed on top of it, and a mercury lamp (manufactured by Dainippon Screen Co., Ltd.) was used to illuminate the film at an illuminance of 25 W/%. The roots were exposed to light for 5 minutes. After removing the negative film, heat the film at 40°C with neutral water containing 2% by weight of sodium alkylnaphthalene sulfonate.
After developing with a brush for 1 minute, a printing plate with an image pattern with a relief depth of 1.2 1 II m was obtained. This image pattern faithfully reproduced the image on the negative film used. Furthermore, the obtained relief had good ink acceptance and transferability and showed a clear image.

The resulting printing plate was heated to 25°C and treated with brimocyanin (
Crystal Violet) was immersed in a 1.0% aqueous solution for 30 minutes, a 2μ-section was prepared using a cryomicrotome (Reichert Ultracut N), and observed using a reflective W4 microscope. As a result, it was found that polymer (1) was selectively dyed and present around each microparticle, and that a plurality of microparticles aggregated to form dispersed particles.

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 (1) of Example 1. The image of the negative film was faithfully reproduced, and a relief with excellent ink transferability was obtained.

Further, when the sample was 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 Relief was produced in the same manner as in Example 1 except that 17.9 parts of N,N-dimethylethyl methacrylate was used instead of 4.8 parts of lithium hydroxide in the hydrophilic polymer (1) of Example 1. When the pattern was obtained, a relief that faithfully reproduced the negative film image and had excellent ink acceptance and transferability was obtained.

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

Example 4 Same as 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 (1) of Example 1. When a relief pattern was obtained using this method, a relief pattern that faithfully reproduced the negative film image and had excellent ink acceptance and transferability was obtained. Example 5 A relief pattern was obtained in the same manner as in Example 1 except that sodium chloride carboxyl group-containing polyisoprene (Kuraprene LrR-840 Kuraray ■) was used instead of the hydrophilic polymer [I] in Example 1. The image of the negative film was faithfully reproduced, and a relief with excellent ink acceptance and transferability was obtained.

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

Example 6 In Example 1, sodium chloride carpoxyl group-containing nitrile butadiene rubber (sodium chloride NIPOL 1072 Nippon Zeon ■) was used instead of the hydrophilic raw polymer (1).
A relief pattern was obtained in the same manner as in Example 1 except that the image on the negative film was faithfully reproduced.
A relief with excellent ink acceptance and transferability was obtained.

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

Example 7 In Example 1, in place of the hydrophilic biopolymer (1), sodium chloride and carboxylic group-containing styreptadiene (S
A relief pattern was obtained in the same manner as in Example 1 except that N-307 Sumitomo Naugatac ■) was used, and a relief that faithfully reproduced the image of the negative film and had excellent ink acceptance and transfer properties was obtained.

Further, when the sample was 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 A relief pattern was obtained in the same manner as in Example 1 except that shrimp chlorohydrin rubber (Ebichromer H manufactured by Osaka Soda ■) was used instead of the chlorinated polyethylene in Example 1, and the image on the negative film was faithfully reproduced. A relief with excellent ink transferability was obtained.

Further, when the sample was 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 styrene-butadiene-styrene block copolymer (Kraton 1101 (trade name) manufactured by Shell Petrochemical Co., Ltd.) was used instead of chlorinated polyethylene in Example 1. In some cases, the image of the negative film was faithfully reproduced, and a relief with excellent ink acceptance and transferability was obtained.

Furthermore, when the sample was stained with Crystal Bioresotho in the same manner as in Example 1 and observed under a microscope, the same cross-layer structures as in Example 1 were observed.

Example 1O In Example 1, 7.5 parts of hydrophilic biopolymer (1), chlorinated polyethylene (H-135 Osaka Soda ■
) 47.5 parts, styrene-pukudiene rubber (SBR)
using 15 parts of butadiene oligoacrylate (PB-A Kyoeisha Yushi ■'I), 1 part of benzyldimethylkecool (Irgacure 651 Ciba Geigy side) and 0.5 part of hydroquinone monomethyl ether. After that, a relief pattern was obtained in the same manner as in Example 1, and a relief pattern that faithfully reproduced the negative film image and had excellent ink acceptance and transferability was obtained.Also, as in Example 1, it was stained with crystal violet. However, when observed under a microscope, 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 on the negative film was faithfully reproduced and the ink had excellent transferability. A relief was obtained.

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

Example 12 A relief pattern was obtained in the same manner as in Example 4 except that methyl alcohol was used instead of water, and a relief pattern was obtained that faithfully reproduced the negative film image and had excellent ink acceptance and transfer properties. Obtained.

In addition, when stained with crystal violet and observed under a microscope in the same manner as in Example 1, a phase structure similar to that in Example 1 was observed. Reference Example Table 1 shows the development speed, hardness, and rebound modulus of the reliefs obtained in Examples 1 to 12.

Table 1 (Effects of the Invention) The printing plate of the present invention constructed as described above has contradictory properties such as sufficient rubber elasticity, water developability, and water-based ink resistance. It greatly contributes to environmental hygiene.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the state of a section of the printing plate of the present invention observed with a microscope at a magnification of approximately 400 times. Indicates a phase in which polymer is the main component.

Claims (1)

[Claims] (1) A photosensitive resin printing plate characterized by containing an aggregate of microparticles having a phase mainly composed of a hydrophobic polymer and a phase mainly composed of a hydrophilic polymer.