JPH0658532B2 - Photosensitive resin composition for printing plate material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention eliminates the odor of a plate material in a photosensitive resin plate material, improves the working environment at the time of development, and provides high image reproducibility and printability. The present invention relates to the photosensitive resin composition.

[Conventional technology]

Photosensitive resin plate materials for letterpress, planographic and intaglio printing, which have a structure in which a photopolymerizable photosensitive resin layer is provided on a metal or plastic substrate, have recently been put into practical use. In these plate materials, a negative or positive original drawing film having a transparent portion is adhered to the photosensitive resin layer, and then an actinic ray is irradiated to cause photopolymerization in the photosensitive resin layer corresponding to the transparent portion of the original drawing film. Then, the unpolymerized portion is eluted with a suitable solvent to form a relief on the substrate. As described above, the photosensitive resin composition utilizing the photopolymerization reaction is used for various purposes such as a printing plate.

The photosensitive resin plate material is a polyvinyl cinnamate-based, polyamide-based, polyvinyl alcohol-based, polymethyl acrylate-based, polyacrylonitrile-based photosensitive resin plate, or an unsaturated polyester-based resin having a double bond in the molecule, Examples include unsaturated polyurethane type and silicone type photosensitive resin plate materials. Further, polystyrene-polybutadiene block copolymer,
There is also a photosensitive flexographic plate material using a polystyrene-polyisoprene copolymer, an ethylene-vinyl acetate copolymer, natural rubber, nitrile rubber and the like.

Examples of the photopolymerizable unsaturated compound used in such a photosensitive resin composition include monoacrylates and monomethacrylates as well as polyhydric alcohols such as ethylene glycol and unsaturated carboxylic acids such as acrylic acid and methacrylic acid. Reaction products, polyhydric acrylates, polyhydric methacrylates, acrylamide derivatives, which are synthesized by the reaction of unsaturated epoxy compounds and unsaturated carboxylic acids, polyhydric acrylamides obtained by condensation reaction of acrylamide derivatives and polyhydric alcohols, polyhydric A methacrylamide type photopolymerizable monomer or the like is blended in the base resin alone or in several types.

Many photopolymerizable monomers have a unique odor even when the boiling point is 150 ° C or higher. In particular, when the unsaturated group is an acryloyl group or a methacryloyl group, there is a peculiar irritating odor, and when a large amount of these is used, the resulting photosensitive resin composition or plate material has an irritating odor, or the developing step In the case, the odor of the developing solution, which elutes the unpolymerized portion, gives an operator discomfort.

[Problems to be solved by the invention]

The present invention was created in view of the above-mentioned drawbacks of the prior art, and its object is to suppress the odor of the photopolymerizable unsaturated compound without deteriorating the photosensitive property, developability and printability of the plate material. It is an object of the present invention to provide a photosensitive resin composition capable of remarkably reducing the odor of the material itself and the waste liquid obtained by developing the material.

[Means for solving problems]

The present invention is a photosensitive resin composition comprising at least the following components (a) to (c).

(A) 100 parts by weight of a base resin as a binder (b) It has an ethylenic double bond at the terminal and has a boiling point of 150.
20 to 200 parts by weight of a photopolymerizable unsaturated compound at a temperature of not less than 0 ° C. (c) A compound having a molecular weight of 50 to 2,000 and having one —SH group at the terminal 0.01 to 10 parts by weight Component (a) of the present invention As the base resin used as the binder, all the base resins of the generally used photosensitive resin plate material can be used. Fully and partially saponified polyvinyl acetate, polyvinylpyrrolidone, polyethylene oxide, polyvinyl ether, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, aqueous alkyd resin, polyamide, polyvinyl cinnamylidene acetate, polyvinyl cinnamate / cinnamylidene acetate . Diazo resins such as p-diazodiphenylamine / paraformaldehyde condensation polymer, polyazido vinyl benzoate, azido polymers such as polyazido vinyl phthalate, polystyrene-polyisoprene block copolymers, polystyrene-polybutadiene block copolymers, polyisoprene, Examples thereof include nitrile rubber, synthetic rubber such as polybutadiene, unsaturated polyester having a double bond in the molecule, unsaturated polyurethane, and unsaturated aryl urethane oligomer.

As the photopolymerizable monomer used as the component (b) of the present invention, any photopolymerizable monomer having a certain degree of compatibility with the component (a) can be used. Specifically, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,
Monoacrylates such as 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, and monomethacrylate. Polyhydric acrylates and methacrylates obtained by reacting a polyhydric alcohol such as ethylene glycol with an unsaturated carboxylic acid such as acrylic acid or methacrylic acid. Polyhydric acrylates and methacrylates synthesized by the reaction of polyhydric glycidyl ethers such as ethylene glycol diglycidyl ether and unsaturated carboxylic acids such as acrylic acid and methacrylic acid. Acrylamide, methacrylamide, N-methylol acrylamide, diacetone acrylamide, methylene bis acrylamide, N-methylol acrylamide or polyvalent acrylamide and polyvalent methacrylamide based light synthesized by condensation reaction of N-methylol methacrylamide and polyhydric alcohol Polymerizable monomers are mentioned. Further, vinyl compounds such as divinylbenzene can also be used.

The component (b) needs to have a boiling point of 150 ° C. or higher. If the boiling point is less than 150 ° C, the photopolymerizable monomer may scatter during molding of the plate material, or the photopolymerizable monomer may scatter during storage of the raw plate, resulting in unstable performance.

When the amount of the component (b) used is less than 20 parts by weight based on 100 parts by weight of the base resin of the component (a), the density of the crosslinked structure produced by photopolymerization is insufficient, and sufficient image reproducibility is obtained. I can't. On the other hand, if the amount of the component (b) used exceeds 200 parts by weight, the density of the crosslinked structure formed by photopolymerization becomes excessive, so that the obtained relief becomes extremely brittle. Therefore, problems such as cracking of the relief during printing occur. For the above reasons, the amount of the photopolymerizable monomer as the component (b) used is 2 per 100 parts by weight of the component (a).
The range of 0 to 200 parts by weight is necessary, and preferably 50.
~ 150 parts by weight.

The compound having one --SH group at the terminal used as the component (c) of the present invention is a photosensitive resin composition prepared by blending the base resin of the component (a) with the photopolymerizable unsaturated compound of the component (b). Odor can be eliminated by being mixed in.

Examples of the compound used as the component (c) of the present invention include:
Ethyl thiol, propyl thiol, isopropyl thiol, n-butyl thiol, allyl thiol, n-pentyl thiol, n-hexyl thiol, n-peptyl thiol, n-octyl thiol, n-nonyl thiol,
Alkyl thiols such as n-decyl thiol, n-undecyl thiol, n-dodecyl thiol, n-tridecyl thiol, and n-octadecyl thiol. Aromatic thiols such as thiophenol and benzylthiol. 2-mercaptoethanol, 2-mercaptopropanol, 2-
Alkanolthiols such as mercaptopentanol, 2-mercaptohexanol, 2-mercaptoheptanol, 2-mercaptooctanol, ethylenethioglycol and thioglycerin. Examples thereof include, but are not limited to, thiocarboxylic acids such as thioacetic acid, thioglycolic acid, and thioacrylic acid. N-decyl thiol, n-undecyl thiol, n-dodecyl thiol, n-tridecyl thiol, ethylene thioglycol and thioglycerin are particularly preferably used.

The molecular weight of component (c) must be in the range of 50 to 2,000. If the molecular weight is less than 50, the volatility is remarkably high, and most of it scatters during preparation of the photosensitive resin composition or molding of the plate material. Conversely, the molecular weight is 2,0
If it exceeds 00, the compatibility with the photosensitive composition decreases, and it cannot be often used. For the above reasons, the molecular weight of the component (c) needs to be in the range of 50 to 2,000, and more preferably 70 to 1,000.

The amount of the component (c) used is 0.01 to 10 parts by weight based on 100 parts by weight of the base resin of the component (a). (C)
If the amount of the component used is less than 0.01 parts by weight, the deodorizing ability due to the addition of the component (c) is small and the effect is not exhibited. Further, if the amount used exceeds 10 parts by weight, the photopolymerization reaction is often hindered, and the odor of the component (c) itself becomes significant in many cases. For this reason, the amount of the compound having one —SH group at the terminal of the component (c) is such that the base resin 10 of the component (a) is used.
It is necessary to be in the range of 0.01 to 10 parts by weight with respect to 0 parts by weight, preferably 0.05 to 5 parts by weight. Further, as the component (c), it is possible to use a mixture of two or more kinds.

As the photosensitizer for promptly carrying out the photopolymerization reaction of the composition of the present invention, all conventionally known compounds can be used. Examples thereof include benzoin alkyl ethers, benzophenones, anthraquinones, benzyls, acetophenones, diacetyls and the like.

These photosensitizers are used in an amount of 0.01-10 based on the total composition.
It can be used in the range of% by weight.

Any conventionally known polymerization inhibitor can be used to increase the thermal stability of the photosensitive resin composition of the present invention. Preferred thermal polymerization inhibitors include phenols, hydroquinones, catechols and the like. These heat stabilizers can be used in the range of 0.001 to 5% by weight with respect to the total amount of the composition. Further, dyes, pigments, surfactants, defoaming agents, ultraviolet absorbers, fragrances and the like can be added.

As a method for producing the photosensitive resin composition of the present invention,
After the base resin of the component (a) is dissolved alone or in a mixed solvent by heating, the photopolymerizable monomer of the component (b) and the − of the component (c)
It is general to add a compound having one SH bond, a photosensitizer, a heat stabilizer and the like, and stir to mix them sufficiently. In this way, a photosensitive resin solution is obtained.

In order to form the photosensitive layer from the above mixed solution, for example, most of the solvent may be distilled off and then heated to a molten state and extruded on a support. It is also possible to form a photosensitive sheet by a dry film-forming method and adhere the sheet to a support to form a photosensitive layer. Further, a photosensitive layer can be obtained by directly forming a dry film on the support.

As the support, a metal plate such as steel, stainless steel, aluminum, or copper, a plastic sheet such as a polyester film, or a synthetic rubber sheet such as a styrene-butadiene copolymer is used. The photosensitive layer is 0.1 to 10
It is preferably formed to have a thickness of mm.

In order to form a relief image for printing using the photosensitive resin composition of the present invention, a negative or positive original drawing film is adhered on the photosensitive layer prepared as described above, and usually a wavelength of 300 to 400 nm is centered. High pressure mercury lamp,
Ultraviolet light from ultra-high pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, etc. is irradiated and cured by photopolymerization by photopolymerization. Next, the unpolymerized portion is eluted into the solvent by using a spray developing device or a brush developing device to form a relief on the support.

The photosensitive resin composition of the present invention eliminates the odor found in the plate material itself or the developer that develops the plate material, and can improve the working environment of the plate making and developing operator. This is brought about by adding an appropriate amount of the compound having one -SH group as the component (c). Although the mechanism is not clear, since the --SH group at the end of the component (c) is highly reactive, it is possible to remove the aldehydes such as the aldehydes that cause the pungent odor contained in the photopolymerizable monomer of the component (b). It is considered that it may react with impurities and become odorless. However, the compound as the component (c) generally has a strong odor and has a property of inhibiting photopolymerization. Therefore,
It is necessary to carefully determine the addition amount of the component (c). That is, the addition amount of the component (c) must be minimized to improve the odor, and addition of more than that reduces the odor and image reproducibility.

The photosensitive resin composition of the present invention is most effective when used as a relief printing material, but can also be used as a lithographic printing material, an intaglio printing material, a stencil printing material, and a photoresist.

[Examples] The present invention will be described in more detail with reference to Examples below.

Example 1 100 parts by weight of partially saponified polyvinyl acetate having a degree of saponification of 80 mol% and an average degree of polymerization of 900 was ethanol / water = 40/6.
It was dissolved in 250 parts by weight of a mixed solvent of 0 (weight ratio) at 70 ° C. for 2 hours. Next, as a photopolymerizable monomer, 70 parts by weight of a compound obtained by the addition reaction of 1 mol of ethylene glycol diglycidyl ether and 2 mol of acrylic acid was added and sufficiently stirred.

Further, 1 part by weight of thioglycerin, 15 parts by weight of diethylene glycol as a plasticizer, 2 parts by weight of dimethylbenzyl ketal as a photosensitizer, and 0.1 parts by weight of hydroquinone monomethyl ether as a heat stabilizer were added and sufficiently stirred and mixed. In the photosensitive resin solution thus obtained,
No pungent odor was felt.

Next, this photosensitive resin was applied on a steel substrate having a thickness of 300 μ, which had been previously coated and cured with an epoxy adhesive, so that the thickness after drying was 950 μ (including the substrate). Then, this was placed in an oven at 60 ° C. for 4 hours to remove the solvent.

It was confirmed that the obtained plate material and developing waste liquid had almost no odor. It was also confirmed that there was no problem in image reproducibility. The print test results were also good.

Comparative Example 1 A photosensitive resin composition solution was prepared in the same manner as in Example 1 except that 1 part by weight of thioglycerin was not added. This solution had a strong pungent odor.

This photosensitive resin composition was formed into a plate material under the same conditions as in Example 1. The obtained plate material and developing waste liquid had a considerable odor.

From the above results, it was revealed that the addition of thioglycerin markedly reduced the odor of the photosensitive composition and the plate material.

Example 2 100 parts by weight of N-methoxymethylated 6-nylon having a methoxymethylation rate of 30 mol% was added to ethanol / water = 80/2.
It was dissolved in 120 parts by weight of a mixed solvent of 0 (weight ratio) at 80 ° C. with heating. To this, 3 parts by weight of glycidyl methacrylate was added and reacted at 80 ° C. for 1 hour to introduce a double bond at the terminal of nylon. Then, 70 parts by weight of glycerol dimethacrylate as a photopolymerizable monomer, 25 parts by weight of N-butylbenzenesulfonamide as a plasticizer, 0.2 parts by weight of n-dodecylthiol, and 2 parts by weight of benzoin ethyl ether as a photosensitizer were added. Mixed well. The photosensitive resin composition solution thus obtained had almost no odor.

This solution was cast on a 200 μm-thick polyester film to which a polyester-based adhesive had been applied and cured in advance so that the thickness after drying (including the substrate) would be 700 μm. Then, it was placed in an oven at 60 ° C. for 3 hours to remove the solvent. It was confirmed that this plate material was almost odorless and had good photosensitivity. Also, good results were obtained in the print test.

Comparative Example 2 A photosensitive resin composition solution was prepared under the same conditions as in Example 2 except that n-dodecylthiol was not added. This solution had a strong pungent odor.

Next, using this solution, a plate material was prepared in the same manner as in Example 2. The plate material obtained had a considerable pungent odor.

EFFECT OF THE INVENTION Since the photosensitive resin composition according to the present invention is configured as described above, it is possible to remarkably reduce the odor of the photosensitive resin plate material while maintaining good photosensitivity and printability. It has a remarkable practical effect.

Claims (1)

[Claims] 1. A photosensitive resin composition for a printing plate material, which comprises at least the following components (a) to (c). (A) 100 parts by weight of a base resin as a binder (b) It has an ethylenic double bond at the terminal and has a boiling point of 150.
20 to 200 parts by weight of a photopolymerizable unsaturated compound at a temperature of ℃ or more (c) a compound having a molecular weight of 50 to 2,000 and having one -SH group at the terminal 0.01 to 10 parts by weight