JP2002189288A - Photosensitive resin composition and photosensitive resin original plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition and a photosensitive resin original plate excellent in image reproducibility and having a small dot gain and good printing performance. SOLUTION: The photosensitive resin composition has a sea-island structure comprising sea and island parts in which two phases different from each other in horizontal force are present in cross-section observation with a horizontal force microscope (LFM) and >=60% of the island part has <=4 μm2 average domain area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in the fields of relief plates for letterpress printing, relief masks for sandblasting, name plates, and the like, and a water-developable photosensitive resin printing plate excellent in image reproducibility and its photosensitivity. The present invention relates to a photosensitive resin composition used for producing a resin printing plate precursor.

[0002]

2. Description of the Related Art A photosensitive resin printing plate is a relief printing rubber plate comprising a relief formed by using a photosensitive resin composition molded to a predetermined thickness. This is usually a negative or positive film in close contact with the photosensitive resin composition, irradiating active light to expose a selected portion of the photosensitive resin composition layer, and then remove the unexposed portion. It is manufactured by a method of forming a relief.

Conventionally, in manufacturing a photosensitive resin printing plate, a halogenated hydrocarbon such as 1,1,1-trichloroethane has been used to remove an unexposed portion. Had a problem.

In order to solve such a problem, a water developing type flexographic printing has been proposed in recent years. In the photosensitive resin printing plate used for this water-developing type flexographic printing, relief is formed by removing unexposed portions with a dilute aqueous alkali solution such as sodium hydroxide. Due to the solubility of the photosensitive layer in a dilute alkaline aqueous solution and properties such as plate strength required as a printing plate, the photosensitive resin printing plate has a main skeleton containing a styrene unit, a butadiene unit, an alkyl acrylate unit, and the like. Of course, copolymers in which a hydrophilic functional group such as a carboxyl group, a phosphoric acid group, a phosphoric ester group, and a sulfonic acid group has been introduced are frequently used.

[0005] This water-developing type flexographic printing is preferable in terms of environmental hygiene because it uses water-based inks and low-viscosity inks containing alcohol, and it is generally used widely because the printing machine is simple and the productivity is high. ing.

[0006]

However, a photosensitive resin printing plate used for water developing type flexographic printing is made of a material having rubber elasticity, and the printing plate has a relatively large thickness. Therefore, in printing, when the printing plate comes into contact with the printing medium and transfers the ink, the printing plate is deformed, and there is a problem that a so-called dot gain that the printed image becomes larger than the original image may occur. .

Further, the thickness of the photosensitive resin printing plate used in water-developing type flexographic printing is generally thicker than a relief printing plate or a lithographic printing plate using oil-based ink. Therefore, the light necessary to form an image does not sufficiently penetrate to the inside, and letterpress printing or lithographic printing using oil-based ink,
Image reproducibility is inferior to gravure printing and the like, and improvement in the image reproducibility is desired.

In view of the above problems, the present invention provides a photosensitive resin composition having excellent image reproducibility, low dot gain and good printability in water-developing type flexographic printing, and the photosensitive resin composition thereof. The present invention provides a photosensitive resin printing plate using the same.

[0009]

The photosensitive resin composition according to the present invention comprises a horizontal force microscope (L).
The cross section observed by FM) has a sea-island structure composed of a sea portion and an island portion in which two phases having different horizontal forces exist, and 60% or more of the island portion has an average domain area of 4 μm ² or less. It is a conductive resin composition.

[0010] The photosensitive resin printing plate precursor according to the present invention comprises, as described in claim 2, the photosensitive resin composition according to claim 1 and a support film coated with an adhesive layer and an anti-adhesion layer. Is a photosensitive resin printing original plate obtained by sandwiching with a coated cover film to form a laminate, and heating and pressing the laminate.

The present inventors have conducted intensive studies in order to solve the above-mentioned problems. As a result of observing the cross-section of the phase separation structure of the photosensitive resin composition layer with a horizontal force microscope (LFM), it was found that the phases having different horizontal forces were different. Is a sea-island structure composed of a sea portion and an island portion in which two phases exist, and when 60% or more of the island portion is a dense structure with a domain average area of 4 μm ² or less, the printed image is The present invention has been completed on the basis of the fact that the occurrence of the dot gain phenomenon, which becomes large due to the above, can be greatly reduced.

Since 60% or more of the islands in the phase separation structure of the photosensitive resin composition layer have a dense structure having an average domain area of 4 μm ² or less, the force transmitted to the printing original plate during printing is made uniform. Therefore, deformation distortion of the printing plate during ink transfer can be reduced. Therefore, it is considered that the occurrence of the dot gain phenomenon can be suppressed. In the sea-island structure of the photosensitive resin composition, 60% to 80% of the island portion is 0.1 μm
^{When the} thickness is ² to ⁴ μm ² , the force transmitted to the printing original plate during printing is made uniform and clear printing is possible, which is more preferable.

The horizontal force microscope is a device for detecting a small twist as a signal when the lever with the fine projection is operated horizontally on the sample surface with respect to the lever. The degree of the twist has a correlation with the frictional force on the outermost surface of the sample, and it is possible to measure the relative frictional force distribution on the surface of the minute area. That is, it is possible to measure the phase separation structure of the photosensitive resin composition layer, that is, the sea-island structure. The phase separation structure of the photosensitive resin composition layer can be measured by an electron microscope, an atomic force microscope, or the like. However, it is limited only to the case where the height of the sea-island structure is clearly different and the shape is different. That is, when the boundary of the sea-island structure is not clear due to the difference in elevation, such as when a minute sea-island structure is formed, it is impossible to accurately measure the sea-island structure.

The horizontal force microscope obtains the relative frictional force distribution on the surface as a signal depending on the degree of the twist, detects the horizontal force on the material surface, and converts the magnitude of the horizontal force into a two-dimensional image as color contrast. I do. From this two-dimensional image, the occupancy of the island portion in the sea-island structure and the average area of each island portion domain can be analyzed. Since this horizontal force is affected by the viscosity of the sample surface, when observing the phase separation structure,
An image reflecting the hardness of each phase is obtained.

The present inventor has found that this difference in the distribution of the horizontal force affects the deformation distortion of the photosensitive resin printing plate during printing. That is, it is found that the smaller the nonuniformity of the hardness distribution, the smaller the deformation distortion of the printing plate during printing and the lower the dot gain. It is found that 60% or more of the island portions in the sea-island structure is 4 μm ² or less. In the case of, the finding that a good image can be obtained was obtained. In addition,
If 60% or more of the island portions in the sea-island structure exceeds 4 μm ² , the deformation of the printing plate during printing is large, and it is difficult to obtain a good image.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In forming a sea-island type phase structure, when the constituent composition is a non-crosslinked body, a composition having a relatively low viscosity and flowing easily takes a phase structure as a sea portion.
On the other hand, when the structural composition is a non-crosslinked body and a crosslinked body, the crosslinked body does not dissolve in the noncrosslinked body, so that the noncrosslinked body having low viscosity and fluidity also has a phase structure as a sea portion. As described above, the sea-island structure of the photosensitive resin composition according to the present invention may be constituted of a non-crosslinked product and a non-crosslinked product by phase separation.

Further, in the sea-island structure of the photosensitive resin composition according to the present invention, the difference in solubility of the crosslinking component between the sea portion and the island portion is utilized to determine the properties recognized by a horizontal force microscope and the properties of each phase. The scale can be controlled artificially.

Crosslinkable particulate hydrophilic or water-swellable elastomers are aliphatic conjugated diene monomers 40-95.
Mol%, α, β-ethylenically unsaturated carboxylic acid 1 to 3
It can be obtained by radical emulsion polymerization of a monomer mixture containing 0 mol and 0.1 to 10 mol% of a compound having at least two addition-polymerizable groups.

As the aliphatic conjugated diene monomer, for example, butadiene, isoprene, dimethylbutadiene, chloroprene and the like can be used. The α, β-
As the ethylenically unsaturated carboxylic acid, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetraconic acid, protonic acid and the like can be used. Examples of the compound having at least two groups capable of addition polymerization include trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, divinylbenzene, and ethylene glycol di (meth).
Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-heptanediol di (meth) acrylate, and the like can be used.

The emulsion polymerization can be adjusted by a usual polymerization method. For example, it can be adjusted by emulsion polymerization of a mixture of monomers in an aqueous medium containing sodium persulfate as a catalyst and sodium dodecylbenzenesulfonate as an emulsifier.

The cross-linked particulate hydrophilic or water-swellable elastomer comprises a core having a cross-linked structure of 10% or less, and a cell having a non-cross-linked structure which can be treated with an aqueous system and which is composed of an acid-modified copolymer. The emulsion polymerization can be carried out so as to have a core cell microgel binder structure consisting of

As monomers forming the core, for example, methyl methacrylate, ethyl acrylate, methacrylic acid, butyl methacrylate, ethyl methacrylate, glycidyl methacrylate, styrene and allyl methacrylate can be used. As the crosslinking agent, for example, butanediol acrylate, ethylene glycol dimethacrylate, tetramethylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylene glycol dimethacrylate and the like can be used. on the other hand,
As the acid-modified copolymer for forming cells, n-butyl acrylate modified with methacrylic acid can be used. The coacerv microgel binder is produced using these monomers by a commonly used emulsion polymerization method.

The cross-linked or non-cross-linked particulate hydrophilic or water-swellable elastomer is obtained by converting a monoolefinic unsaturated monomer and an unsaturated monomer having a hydrophilic functional group into an anionic surfactant. It can be obtained by emulsion polymerization using an agent.

The monoolefinically unsaturated monomers include:
For example, methyl acrylate, ethyl acrylate,
Acrylic esters such as n-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, cyanoethyl acrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate, and methacrylic esters thereof And the like, and styrene, acrylonitrile, vinyl chloride, ethylidene norbornene, propenyl norbornene, dicyclopentadiene and the like can also be used. In some cases, 1,3-
A conjugated diene-based monomer such as butadiene, isoprene, chloroprene, or 1,3-pentadiene can be used, and a polyfunctional vinyl compound can be introduced for crosslinking.

Examples of the hydrophilic functional group include a carboxyl group, a phosphoric acid group, a phosphoric acid ester group, a sulfonic acid group, and a hydrohistyl group, and a phosphoric acid ester group is particularly preferable from the viewpoint of washability. Therefore, the unsaturated monomer having a hydrophilic functional group is preferably the above-mentioned unsaturated monomer having a phosphate group. Examples of the phosphate group-containing unsaturated monomer include ethylene phosphate (meth) acrylate, trimethylene phosphate (meth) acrylate,
Propylene (meth) acrylate, tetramethylene (meth) acrylate, (bis) ethylene (meth) acrylate, (bis) trimethylene (meth) acrylate, (bis) tetramethylene (meth) acrylate , Diethylene glycol (meth) acrylate phosphate, triethylene glycol (meth) acrylate phosphate, polyethylene glycol (meth) acrylate phosphate, (bis) diethylene glycol (meth) acrylate phosphate, (bis) triethylene glycol (meth) phosphate Acrylate, phosphoric acid (bis)
Polyethylene glycol (meth) acrylate or the like can be used.

The non-crosslinked particulate hydrophilic or water-swellable elastomer can be formed as particles having a phase mainly composed of a hydrophobic polymer and a phase mainly composed of a hydrophilic polymer. .

The hydrophobic polymer may be a polymer obtained by polymerizing a conjugated diene hydrocarbon, a copolymer obtained by polymerizing a conjugated diene hydrocarbon and a monoolefinic unsaturated compound, or a conjugated diene hydrocarbon. For example, a polymer containing no hydrogen can be used.

Examples of a polymer obtained by polymerizing a conjugated diene-based hydrocarbon or a copolymer obtained by polymerizing a conjugated diene-based hydrocarbon and a monoolefinic unsaturated compound include, for example, a butadiene polymer and a isoprene polymer. Coalescing,
Chloroprene polymer, styrene-butadiene copolymer,
Styrene-isoprene copolymer, styrene-chloroprene copolymer, acrylonitrile-butadiene copolymer,
Acrylonitrile-isoprene copolymer, methyl methacrylate-butadiene copolymer, methyl methacrylate-isoprene copolymer, methyl methacrylate-chloroprene copolymer, methyl acrylate-butadiene copolymer, methyl acrylate-isoprene copolymer A copolymer, a methyl acrylate-chloroprene copolymer, an acrylonitrile-butadiene-styrene copolymer, an acrylonitrile-chloroprene-styrene copolymer, or the like can be used.

Examples of the polymer containing no conjugated diene-based hydrocarbon include elastomers containing a specific amount of chlorine and non-conjugated diene-based hydrocarbons. More specifically, epichlorohydrin polymer, epichlorohydrin- Ethylene oxide copolymer, epichlorohydrin-propylene oxide copolymer and / or epichlorohydrin rubber which is a copolymer of these and acrylic glycidyl ether [Epichromer manufactured by Osaka Soda Industry Co., Ltd., HYDRIN manufactured by Goodvich Co., Ltd., Nippon Zeon Co., Ltd.] GECHRON, Zeospan, Hevcu
HERCLOR manufactured by LES Co., Ltd., chlorinated polyethylene [Eraslen manufactured by Showa Denko KK, Osaka Soda Industry Co., Ltd.]
Daisorac, Hoechst HORTAL
ITZ, Dow Chemical Co., Ltd. Dow C
PE] or the like can be used.

These hydrophobic polymers may be used alone or in combination of two or more, and the content in the composition is 2%.
It is preferable that the content be 0% by weight or more and 80% by weight or less. 2
If it is 0% by weight or less, the handling property is significantly impaired, and if it is 80% by weight or more, the water developability is impaired. A particularly preferred content is 30% by weight or more and 70% by weight or less.

On the other hand, the hydrophilic polymer which mainly forms the outer phase surrounding the particles includes a hydroxyl group, a carboxyl group,
A polymer having either a hydrophilic group such as an amino group or a sulfonic acid group or a polyethylene glycol chain is exemplified.

As the hydrophilic polymer, for example,
Polyvinyl alcohol, carboxymethyl cellulose,
Hydroxyethyl cellulose, water-soluble polyurethane, water-soluble polyurea urethane, water-soluble polyester, water-soluble epoxy compound, carboxyl group-containing acrylonitrile-butadiene copolymer, carboxyl group-containing styrene-butadiene copolymer, carboxyl group-containing polybutadiene, polyacrylamide, polyacrylic acid Sodium, carboxyl group polyurea urethane, polyamic acid and the like can be used.

In the case of the composition, each component is blended,
Those which form a continuous phase and a dispersed phase by phase separation during mixing are preferable, and the content of the hydrophilic polymer is preferably 1% by weight or more and 40% by weight or less from the viewpoint of water developability and aqueous ink resistance. Is from 2% by weight to 30% by weight, particularly preferably from 3% by weight to 20% by weight.

The above-mentioned particulate hydrophilic or water-swellable elastomer preferably has a water-swellable elastomer content of 20% by weight or more and 80% by weight or less, more preferably, in the total composition. It is 30% by weight or more and 70% by weight or less. If less than 20% by weight, developability,
A problem occurs in the shape retention characteristics and the like, and when it exceeds 80% by weight, a problem occurs in water resistance, which is not preferable.

A sea-island structure in which 60% or more of the island portion is 4 μm ² or less can be obtained by mixing the above-mentioned particulate hydrophilic or water-swellable elastomer with a hydrophobic polymer in an arbitrary ratio. As a method for forming a sea-island structure in which 60% or more of the island portion is 4 μm ² or less, in addition to the above-mentioned emulsion polymerization method, adjustment is performed by melt extrusion, mill blending, or other means to adjust the photosensitive resin composition. It is also possible to sometimes disperse, and the method for producing the photosensitive resin composition according to the present invention is not limited to these methods.

The island portion in the sea-island structure of the photosensitive resin composition according to the present invention is present as a cell component in which the dispersed particles are water-insoluble, are soluble or swellable or dispersible in an aqueous medium, and are dispersed. By using such a core cell particle structure-based photosensitive resin composition, a photosensitive resin printing original plate having a water-based developable developing system can be obtained.

The above-mentioned emulsion polymerization method is a method in which each monomer is copolymerized in an aqueous medium containing an emulsifier and a polymerization initiator. As an emulsifier, for example,
Alkyl benzene sulfonate, alkyl sulfonate, alkyl sulfate, fatty acid metal salt, polyoxyalkyl ether sulfate, polyoxyethylene carboxylate sulfate, polyoxyethylene alkyl phenyl ether sulfate, dialkyl succinate Ester sulfonates and the like can be used. These may be used alone or in combination of two or more. On the other hand, as the polymerization initiator,
A combination of a water-soluble inorganic peroxide or a water-soluble reducing agent and an organic peroxide is used. Examples of the water-soluble inorganic peroxide include potassium persulfate and ammonium persulfate. As the water-soluble reducing agent, for example, a reducing agent used as a normal water-soluble radical redox polymerization catalyst component, for example, ethylenediaminetetraacetic acid or its sodium or potassium salt, or iron and iron,
Complex compounds with heavy metals such as copper and chromium, sulfinic acid or its sodium or potassium salt, L-ascorbic acid or its sodium salt, potassium salt, calcium salt, ferrous pyrophosphate, ferrous sulfate, ferrous sulfate Iron ammonium, sodium sulfite, sodium acid sulfite, sodium formaldehyde sulfoxylate, reducing sugars and the like can be used, and these may be used alone or in combination of two or more. Examples of the organic peroxide include cumene hydroperoxide, p
Using hydroperoxides such as cymene hydroperoxide, t-butylisopropylbenzene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, decalin hydroperoxide, t-amyl hydroperoxide, t-butyl hydroperoxide, isopropyl hydroperoxide can do. One of these organic peroxides may be used, or two or more thereof may be used in combination.

In the present invention, in order to artificially control the difference in horizontal force between the phases, it is necessary to effectively express the difference in crosslinking density. Therefore, it is preferable to add a specific amount of the specific ethylenically unsaturated compound.

The specific ethylenically unsaturated compound is a compound having a molecular weight of 500 or less and having at least two or more ethylenically unsaturated groups at a terminal or a side chain.

Examples of the specific ethylenically unsaturated compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate,
1,4-butanediol di (meth) acrylate, 1,
6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin di (meth) acrylate, triethylene glycol di (meth) acrylate, PEG # 200 di (meth) acrylate, PEG # 400 di (meth) ) Acrylate,
1,3-butanediol dimethacrylate, neopentyl glycol di (meth) acrylate, 1,10-decanediol dimethacrylate, ethylene oxide adduct di (meth) acrylate of bisphenol A, ethylene oxide-modified trimethylolpropane triacrylate, penta Erythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 1,9-nonanediol di (meth) acrylate, light ester P-2M (manufactured by Kyoeisha Chemical Co., Ltd.), 3-mol ethylene oxide adduct of pentaerythritol Triacrylate, oligopropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, etc. can be used. Alkylene glycol and polyalkylene ether-based crosslinking agent is preferred.

In the present invention, the specific ethylenically unsaturated compound may be used in combination with a compound having a molecular weight of 1,000 or more and having an ethylenically unsaturated group at a terminal or a side chain. Such materials include oligobutadiene (meth) acrylate, oligostyrene butadiene (meth) acrylate, oligonitrile butadiene (meth) acrylate, oligoisoprene (meth) acrylate, oligobutadiene urethane (meth) acrylate, and oligostyrene butadiene (meth) A) acrylate, oligobutadienamide (meth) acrylate, and the like can be used, but are not limited thereto. Such a compound having an ethylenically unsaturated group having a molecular weight of 1,000 or more can be used by being mixed with the above-mentioned specific ethylenically unsaturated compound at an arbitrary ratio.

Examples of the initiator include benzophenones, acetophenones, α-diketones, acyloins, acyloin ethers, benzylalkyl ketals, polynuclear quinones, thioxanthones, acylphosphines and the like. Specifically, benzophenone, chlorobenzophenone, acetophenone, benzyl, diacetyl, benzoin, bivaloin, benzoin methyl ether, benzoin ethyl ether, benzyl diethyl ketal, benzyl diisopropyl ketal, anthraquinone, 1,4-naphthoquinone, 2-chloroanthraquinone, thioxanthone, -Chlorothioxanthone, acylphosphine oxide, and the like, which may be used alone or in combination;
Preferably, it is blended in a composition of 10 to 10% by weight.
If it is less than 0.01% by weight, it cannot function as an initiator, and if it exceeds 10% by weight, the function of an internal filter becomes strong and the internal curing becomes insufficient. More preferably, it is 0.5 to 5% by weight.

The photosensitive resin composition according to the present invention may contain 0.001 to 5% by weight of hydroquinone, hydroquinone monomethyl ether, 2,6-di-tert-butyl-p-cresol or the like as a stabilizer. Good. The physical properties of the photocured product can be changed by adding a low molecular weight plasticizer such as an ester or an amide as a plasticizer, or an oligomer such as a polyester, a polyether, or a liquid rubber.

The photosensitive resin composition according to the present invention can be formed into a sheet having a desired thickness by any known method such as hot pressing, casting, melt extrusion, and solution casting. Further, the sheet-like material can be laminated on a support with or without a known adhesive. As such a support, any material such as steel, aluminum, glass, a plastic film such as a polyester film, and a metal-deposited film can be used.

In producing the photosensitive resin printing original plate, for example, a method of increasing the temperature when forming the photosensitive resin printing original plate and performing a heat treatment, a method of heating the formed photosensitive resin printing original plate, and the like are employed. be able to.

As a method of heat-treating by elevating the temperature when forming the photosensitive resin printing plate precursor, the photosensitive resin composition is extruded into a sheet shape, and the support film coated with the adhesive layer and the anti-adhesion layer are coated. In the case of laminating by sandwiching with the covered film, the photosensitive resin temperature is kept high or the laminating apparatus itself is set at a high temperature. That is, the photosensitive resin composition, a polyethylene terephthalate film coated with an adhesive layer, and a slip coat layer mainly composed of a water-soluble resin sandwiched between a polyethylene terephthalate film coated to form a laminate, The laminate can be manufactured by heating and pressing. The support film coated with the adhesive layer and the cover film coated with the anti-adhesion layer may be used to form the photosensitive resin composition according to the present invention into a sheet, and then store or operate the photosensitive resin composition after contamination or damage. Used to prevent The support film and the cover film can be peeled off.

The method of heating the formed photosensitive resin printing plate can be easily carried out by treating the photosensitive resin printing plate with a known heating device such as a hot plate, hot air, far-infrared ray or high frequency irradiation as a heat source for a certain period of time. You. Any method may be used as long as the photosensitive resin printing plate can be maintained at a constant temperature. However, the developability and physical properties as the required characteristics of the photosensitive resin printing plate precursor, as well as the shape such as thickness and smoothness for the final use must not be impaired.

The developing step using the water-developable photosensitive flexographic printing plate of the present invention will be described. After applying an inspection negative and irradiating with ultraviolet light under appropriate exposure conditions, a non-image portion is removed using a developing solution to obtain a water-developable photosensitive resin printing plate. Examples of the developing solution include p containing water for daily use in general.
Water having an H of 5.0 to 9.0 is optimal, and may further contain an alkaline compound, a surfactant, a water-soluble organic solvent, and in some cases, an organic acid. As the above-mentioned surfactant, sodium alkylnaphthalenesulfonate, sodium alkylbenzenesulfonate, sodium alkylbenzenesulfonate and the like are most suitable, and in addition, anionic surfactants, nonionic surfactants, and amphoteric surfactants are preferable. Can be used. Furthermore, the temperature of the developer is 25 to 5
It is preferably used at 0 ° C.

[0049]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. In addition, "parts" means parts by weight, and each evaluation was evaluated by the following measurement methods.

The horizontal force microscope (LF) which is important in the present invention
M) is a type of scanning probe microscope (SPM),
The SPM currently on the market is usually a standard observation mode. General SPM on the market
If so, the manufacturer of the device to be used is not limited. In the present invention, SPI3800 / SPA300 manufactured by Seiko Instruments was used. Note that a scanning probe microscope refers to various local physical interactions (force, tunnel current,
This is a general term for a microscope that obtains information on the shape of the sample surface and information on other surface characteristics by utilizing magnetic force, frictional force, and the like.

The LFM measurement conditions were as shown below. Model: Seiko Instruments SPI
3800 system-SPA300 cantilever: OMCL-RC800PSA · kz (spring constant) = 0.09 N / m (manufactured by Olympus Optical Co., Ltd.) (The cantilever must have an appropriate spring constant depending on the sample.) Measurement environment: Temperature 20 ° C, Humidity 65% Scanner: 20 μm scanner and 100 μm scanner Scanning speed: 0.25-4 Hz Force Reference at move in:
Force Reference at -1 nm measurement: 0.0 nm
~ -30 nm

The preparation of the LFM sample was as follows. Temperature of sample minus 50 degrees to minus 1
After cooling to 20 degrees, a self-made glass knife was used to prepare a thin film sample with a cross section of the printing plate exposed using a cryomicrotome, and used as a sample for LFM. Therefore, the LFM observation surface is a cross section inside the plate. Efforts must be made to make the observation surface as smooth as possible, and optimum conditions such as the cooling temperature for sampling must be appropriately selected. The sample thickness was 500 nm or more.

(Example 1) 29.0 parts of polytetramethylene glycol (G-850, manufactured by Hodogaya Chemical Co., Ltd.) 62.0 parts of dimethylolpropionic acid (manufactured by Yoshitsuka Fujii), 119.0 parts of hexamethylene diisocyanate A solution prepared by dissolving 5.0 parts of n-butyltin dilaurate in 300.0 parts of tetrahydrofuran was placed in a 1-liter flask equipped with a stirrer, and the flask was heated to 65 ° C. while stirring was continued. Heated and reaction continued for 3 hours. Further, 26.0 parts of hydroxyethyl methacrylate was added, and the reaction was continued for 2 hours while heating to 65 ° C.

In a separate container, acrylonitrile containing terminal amino groups, butadiene oligomer (Hycar ATBNX)
A solution prepared by dissolving 184.0 parts (1300 × 16, manufactured by Ube Industries) in 270.0 parts of tetrahydrofuran 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 the contained carboxyl group was treated with lithium hydroxide and magnesium acetate to obtain a hydrophilic polymer A.

16 parts of the above-mentioned hydrophilic polymer A, 32.5 parts of butadiene rubber (JSR BROLL), 38 parts of oligobutadiene acrylate (PB-A manufactured by Kyoeisha Chemical Co., Ltd.), 1,6-hexanediol dimethacrylate 3
Parts, 2 parts of dimethylbenzyl ketal as photoinitiator,
Hydroquinone monomethyl ether (0.2 part) was mixed with 80 parts of toluene and 16 parts of water using a heating kneader to form 105 parts.
C., and then toluene and water were distilled off under reduced pressure.
A film obtained by coating the obtained photosensitive resin composition with a polyester adhesive layer on a polyethylene terephthalate film having a thickness of 125 μm, and an anti-adhesion layer (containing polyvinyl alcohol, propylene glycol, and a surfactant on the same polyethylene terephthalate film). ) Is sandwiched between the coated films (so that the adhesive layer and the anti-adhesion layer are in contact with the photosensitive resin composition), and heated and pressed at 105 ° C. under a pressure of 100 kg / cm ² for 1 minute with a heat press. A 1.7 mm photosensitive resin printing plate was prepared.

The cover film of the obtained photosensitive resin printing original plate was peeled off, and the halftone dot 200 line 1% to 95%, the minimum independent point diameter 100 μm, the minimum convex character, 1 point, the minimum extracted character 1 point solid image, step With an inspection negative including a guide, the illuminance at 365 mm light is about 17.5 w / m.
^{2 Using a} lamp FR20T12-BL-9-BP (manufactured by Anderson A Vreland), back exposure and front exposure were performed to remove the negative film, and 40 ° C. containing 4% by weight of sodium alkylnaphthalenesulfonate was used.
For 10 minutes and dried for 60 minutes for 20 minutes. Further, exposure was performed from the table to obtain a photosensitive resin printing plate.

As a result of observing the phase structure in the cross section of the obtained photosensitive resin printing plate after exposure and curing by LFM, a sea-island structure consisting of a sea portion and an island portion was obtained, and 60% or more of the island portion had a domain average. It had a phase structure with an area of 4 μm ² or less. The relief depth is 0.8 mm, the halftone dot 200 line is 1% to 95%, the minimum independent point diameter is 100 μm,
An image reproducibility that could not be realized by a conventional photosensitive resin printing plate that reproduced a minimum independent line width of 30 μm, a minimum line width of 100 μm, a minimum convex character of 1 point, and a minimum character of 1 point was obtained.

Example 2 The procedure of Example 1 was repeated except that 3 parts of dipentaerythritol hexaacrylate was used instead of 3 parts of 1,6 hexanediol methacrylate. Similar results were obtained.

Comparative Example 45 parts of chlorinated polyethylene (manufactured by Daisorac H-135 Daiso Co., Ltd.) and butadiene rubber (manufactured by JSR BROLL Nippon Synthetic Rubber Co., Ltd.) 14
Parts, butadiene oligoacrylate (PB-A Kyoeisha Chemical Co., Ltd.) 25 parts, 1,6 hexanediol dimethacrylate 2.5 parts, dipentaerythritol hexaacrylate 2.5 parts, hydrophilic polymer A 10.5 parts, 2 parts of benzyldimethyl ketal and 0.3 part of hydroquinone monomethyl ether were mixed in the same manner as in Example 1 to prepare a photosensitive resin printing plate. When the phase structure was observed by LFM, a two-phase structure was confirmed.
The above-mentioned phases have a domain average area of 80 μm ² or more. When evaluation was performed in the same manner as in Example 1,
Halftone dot 150 line 3% ~ 95% Minimum independent point diameter 200μm,
Only the image reproducibility of a minimum independent line width of 5 μm, a minimum line width of 150 μm, a minimum convex character of 3 points, and a minimum character of 4 points was obtained.

It should be noted that the embodiments and examples disclosed this time are illustrative in all aspects and are not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0062]

The photosensitive resin printing plate precursor according to the present invention is a photosensitive resin printing plate precursor having excellent image reproducibility, low dot gain and good printability, which has not been achieved in the past.
Therefore, clear image reproducibility could be provided in various fields such as relief printing plates for relief printing, relief masks for sandblasting, and name plates.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takatoshi Yamada 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Research Institute (72) Inventor Keizo Kawahara 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd. Research Laboratory (72) Inventor Satoshi Imahashi 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. Research Laboratory F-term (reference) 2H025 AA00 AA04 AA12 AB02 AB11 AB20 AC01 AD01 BC31 DA09 EA08 FA03 FA17 2H096 AA00 AA02 AA30 BA05 BA20 CA16 EA02 GA08 LA17

Claims (2)

[Claims] 1. A cross-sectional observation using a horizontal force microscope (LFM) has a sea-island structure including a sea portion and an island portion in which two phases having different horizontal forces exist, and 60% or more of the island portion is a domain. A photosensitive resin composition having an average area of 4 μm ² or less. 2. A laminate comprising the photosensitive resin composition according to claim 1 sandwiched between a support film coated with an adhesive layer and a cover film coated with an anti-adhesion layer, to form a laminate. A photosensitive resin printing original plate obtained by heating and pressing.