JPS62133449A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To form a photosensitive resin composition capable of endowing a photocross-linked product with good resistances to solvents and water, and strong adhesion to a printing plate base even in the case of a water-developed type by incorporating a copolymer composed mainly of vinylidene chloride and (meth)acrylic acid or its derivative as the essential component of the photosensitive resin composition. CONSTITUTION:The photosensitive resin compositionis composed essentially of the copolymer composed mainly of vinylidene chloride and (meth)acrylic acid or its derivative, and this composition has affinity to a water-soluble photosensitive polymer composition in a state of aqueous solution, and rich stability, and the film obtained by coating and drying it can well disperse water. Therefore, it can be developed with water, and in addition, the photocross-linked product obtained by exposing said composition is extremely excellent in resistances to solvents and water, and superior in adhesion to the printing plate base, thus permitting printing resistance to various kinds of printing inks to be enhanced remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive resin composition having excellent water-developable performance for making printing plates, particularly screen printing plates.

The photosensitive resin composition used as a printing plate-making material has high sensitivity,
In addition to basic performances such as high resolution and storage stability, printing durability is also an extremely important performance. In addition, the printing durability of the photosensitive resin composition must be such that it is not affected by various oil-based and water-based ink components and their solvents, and must have excellent adhesion to the plate base material and abrasion resistance. Conventionally, water-developable photosensitive resin compositions containing aqueous emulsions have often been used. For example, a mixture of a partially saponified polyvinyl alcohol aqueous solution and a polyvinyl acetate aqueous emulsion to which dichromate or diazo resin is added as a photocrosslinking agent (photosensitizer) (Japanese Patent Publication No. 45-22083, Japanese Patent Publication No. 51 -7
No. 403 @) or a photosensitive resin composition prepared by reacting a mixture of a partially saponified polyvinyl alcohol aqueous solution and a polyvinyl acetate aqueous emulsion with N-methylol acrylamide (Japanese Patent Application Laid-open No. 135526/1983). is particularly widely used for making screen printing plates.

However, printing plates obtained by photocrosslinking from photosensitive resin compositions using such aqueous polyvinyl acetate emulsions contain polyvinyl acetate, which inherently has poor solvent resistance. It has the disadvantage of being easily attacked. Therefore, in order to maintain solvent resistance, it is possible to reduce the component ratio of polyvinyl acetate and increase the component ratio of polyvinyl alcohol in the resin composition, but in this case, water resistance decreases and water-based printing Not only is it impossible to use ink, but even organic solvent-based inks absorb moisture in the air during printing when the humidity is high and become water-containing solvents, which corrode the plate. Otherwise, a plate with sufficient printing durability cannot be obtained. Furthermore, a photosensitive resin composition containing an aqueous polyvinyl acetate emulsion has insufficient adhesive strength to a plate substrate such as a polyester screen, and from this point as well, good stiffness resistance cannot be obtained.

In view of the above-mentioned drawbacks of the prior art, the present invention provides a photo-crosslinked product with good solvent resistance, water resistance, and strong adhesion to the plate base material even if it is a water-developable type. An object of the present invention is to provide a photosensitive resin composition that can impart the following properties.

As a result of studying such photosensitive resin compositions, the present inventor found that vinylidene chloride, (meth)acrylic acid and/or
A photosensitive resin composition containing a copolymer containing a copolymer or a derivative thereof as an essential component has an affinity with a water-soluble photosensitive polymer composition in an aqueous liquid state, and has stability. The dried coating film has good water dispersibility, so it can be developed with water.In addition, the photocrosslinked product obtained by exposure has extremely good solvent resistance and water resistance, and is resistant to plate substrates. It has been discovered that the rigidity resistance against various printing inks is significantly improved due to the excellent adhesiveness, and the present invention has been completed.

The present invention will be explained in detail below.

A feature of the present invention is that in a water-developable photosensitive resin composition based on the photosensitive function of a conventionally used partially saponified polyvinyl alcohol and a diazo resin, or a photocrosslinkable polyvinyl alcohol derivative, vinylidene chloride is used. and (meth)acrylic acid and/or its derivatives as essential components, and the aqueous dispersion thereof has good stability and film-forming properties. The dry coating film has good water developability and photosensitive properties, and the photo-crosslinked cured product obtained by exposure has excellent solvent resistance, water resistance, and adhesion to plate substrates. It is something that you have.

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As the combination of water-soluble polymeric substance and photocrosslinking agent used in the present invention, combinations that have conventionally been widely used in photosensitive resin compositions can be used as they are. That is, examples of water-soluble polymer substances include polyvinyl alcohol resin, polyvinylpyrrolidone, polyacrylamide, polyethylene oxide, poly(meth)acrylic acid or its salt, polyvinyl methyl ether, starch and its derivatives, gelatin, casein, etc. However, among these, polyvinyl alcohol-based lit fats are particularly suitable, and in addition to partially or completely saponified polyvinyl acetate with various degrees of polymerization, vinyl acetate as a main ingredient, α-olefin, vinyl propionate, etc. Saponified products of copolymers with monomers that can be copolymerized with vinyl acetate, including esters, unsaturated acids such as crotonic acid and maleic acid, or alkyl esters of these unsaturated acids, and polyvinyl alcohol or modified polyvinyl alcohol. As long as the partially acetalized product, partially urethanized product, etc. have water solubility, they can be used as an aqueous solution.

Photocrosslinking agents for the above-mentioned water-soluble polymer substances include dichromate, diazo resin obtained by polycondensing diphenylamine-4-diazonium salt with varaformaldehyde, and tetrazonium such as diphenyl-4,4'-bisdiazonium chloride. Compound, 4.4'-bisazidostilbene-
Bisazide compounds such as 2,2'-sodium sulfonate, photocrosslinkable monomers having two or more ethylenically unsaturated groups in the molecule such as N,N'-methylenebisacrylamide, and ethylene glycol diacrylate. I can give an example.

In addition, examples of the photosensitive (photocrosslinkable) water-soluble polymer substance used in the present invention include N-methylol acrylamide grafted partially saponified polyvinyl alcohol, and partially saponified polyvinyl alcohol into which a stylpyridinium group has been introduced. .

In the present invention, the copolymer of vinylidene chloride and (meth)acrylic acid and/or its derivatives used as an essential component in addition to the above components includes a copolymer of vinylidene chloride and (meth)acrylic acid, as well as vinylidene chloride. and 2-hydroxy(meth)acrylate, 2-hydroxy(meth)propyl acrylate, 3-chloro-2-hydroxy(meth)acrylate and other hydroxyl group-containing mono(meth)acrylates, methyl(meth)acrylate, (
Alcohol esters of (meth)acrylic acid such as ethyl meth)acrylate and propyl (meth)acrylate, and glycidyl (meth)acrylate, N-methylol(meth)acrylamide, N-ethylol(meth)acrylamide, acrylamide, methacrylic Examples include acid dimethylamide and acrylonitrile. In any of the above-mentioned copolymers, the copolymerization ratio of vinylidene chloride is 60 to 95 mol%, and a particularly preferable range is 70 to 90 mol%. Incidentally, if the copolymerization ratio of vinylidene chloride in the above copolymer is less than 60 mol%, the effect of improving solvent resistance will be insufficient, while if it is more than 95 mol%, the mixing stability of the dispersion and the adhesion to the plate substrate will be insufficient. This should be taken into account as it may worsen the sex.

Incidentally, vinylidene chloride polymers inherently have extremely high solvent resistance, and as is well known, they exhibit very strong resistance to organic solvents other than tetrahydrofuran, and also have excellent water resistance. However, its homopolymer has a strong cohesive force due to the regularity and symmetry of its structure, and the aqueous emulsion is unstable and easily aggregates. When mixed with an aqueous solution, it thickens and gels, causing separation and destruction of the emulsion and formation of coarse particles, which makes it unusable.

Therefore, in the present invention, by using a copolymer of vinylidene chloride and (meth)acrylic acid or a (meth)acrylic acid derivative, the advantages of solvent resistance and water resistance of vinylidene chloride polymer are utilized, and on the other hand, The above-mentioned drawbacks have been successfully eliminated.

That is, the copolymer has not only good stability as an emulsion as an aqueous dispersion (but also a photocrosslinked product of a dry coating formed from the emulsion that has better resistance than that of vinylidene chloride polymer). It exhibits solvent resistance and water resistance, and has particularly excellent adhesion to plate substrates.

As described above, the photosensitive resin composition according to the present invention includes a water-soluble polymer substance and its photocrosslinking agent, or a water-soluble polymer substance having photocrosslinkability, and the above-mentioned vinylidene chloride and (meth).
This composition contains a copolymer with acrylic acid or its derivatives as an active ingredient, but in the present invention, maleic anhydride, fumaric acid, and croton are added to improve the adhesion of the emulsion of the composition to the plate substrate. It is also possible to use a terpolymer in which about 1 to 3 mol % of a copolymerizable unsaturated acid such as acid or itaconic acid is added as a copolymerization component as the above-mentioned copolymer in the present invention. That is, the above-mentioned copolymers used in the present invention also include such terpolymer copolymers.

The content of the copolymer in the photosensitive resin composition of the present invention is 20 to 80% by weight, preferably 40 to 70% by weight, and when the content is lower than 20% by weight, sufficient solvent resistance is obtained. If the amount exceeds 80% by weight, the water developability deteriorates significantly, so care must be taken.

The vinylidene chloride copolymer used in the present invention is mixed with an aqueous solution of a water-soluble polymeric substance or a photosensitive water-soluble polymeric substance and used in the form of an aqueous emulsion. It is recommended to use the emulsification method. That is, the pressure-resistant reaction vessel is replaced with nitrogen under reduced pressure, an anionic or nonionic surfactant such as sodium alkyl phosphate or polyoxyethylene alkylphenyl ether is added to water as an emulsifier for polymerization, and then Potassium persulfate and hydrogen peroxide were added as polymerization initiators, and then the copolymerization monomer mixture, which had been kept in a separate container, was introduced little by little into the reaction container, and the pressure, temperature, and p.
If polymerization is carried out by stirring the mixture in the container while keeping H constant, an aqueous emulsion of the copolymer can be obtained. Note that hydrochloric acid, nitric acid, phosphate, ammonia, etc. are used as the pHlJI moderating agent.

In addition, in the present invention, in order to impart flexibility to the coating film of the photosensitive resin composition, dioctyl phthalate, dibutyl phthalate, dioctyl adipate, etc., which are known as plasticizers for polyvinylidene chloride, are added to the reaction system in advance. Alternatively, it can be added to the produced copolymer emulsion in a secondary step.

In the present invention, in addition to the above, surfactants and antifoaming agents may be added in order to improve the smoothness of the dry coating film formed from the emulsion of the composition of the present invention.
Other additives such as preservatives and colorants may also be added as appropriate.

The photosensitive resin sealing composition according to the present invention obtained as described above is in the form of an aqueous dispersion and can be applied to screen meshes, aluminum slopes, synthetic resin plates or films, semiconductor substrates, glass, and ceramics depending on the application. It is used by coating it on any substrate to a desired thickness and drying it to form a coating film.

The active light for photocrosslinking and curing is mainly 350 to 450n.
Exposure is preferably carried out using ultraviolet rays of m, and after exposure, the unexposed areas are washed out and removed by water development to form an image.

EXAMPLES The preparation of the photosensitive resin composition of the present invention, its use and effects will be specifically explained below with reference to Examples.

In addition, parts in the examples shown below represent weight unless otherwise specified.

Example 1 An aqueous emulsion of vinylidene chloride-acrylonitrile copolymer was added to 100 parts of a 10% aqueous solution of partially saponified polyvinyl alcohol (manufactured by Nippon Gohsen Kagaku Kogyo @ [Gohsenol Gl (-174)) with an average degree of polymerization of 1700 and a degree of saponification of 88 mol%. [Copolymerization ratio (mole) 90:10, solid content concentration 45%] 30 parts, 1 part of diazo resin obtained by polycondensing diphenylamine-4-diazonium sulfate with paraformaldehyde, 0.5 part of aqueous dispersion blue pigment, interface A dispersion of a photosensitive resin composition was prepared by adding and stirring 0.3 parts of polyoxyethylene lauryl ether as an activator.This photosensitive dispersion was applied three times to a 300-mesh polyester screen plate using a packet. After that, drying was repeated to form a photosensitive coating film with a thickness of 12 μm.

75 to 150μ in line on the photoresist surface of this screen photoresist film.
A positive film for printed wiring board printing consisting of lines of 1.5 m was brought into close contact with a vacuum printing frame, and exposed to light from a distance of 1 m for 1 minute and 30 seconds using a 3KW metal halide lamp. To wash out the development, immerse the film in water at 20°C for about 3 minutes to elute the unexposed area, and spray the fine details with a water spray gun with an air pressure of 5 kg/cj to completely elute and remove the unexposed remaining film.
A screen printing plate was prepared by drying with warm air at 40° C. for 20 minutes.

Using this printing plate, UV-curable etching resist ink (TAIYO INK AS-50) was applied to the epoxy copper-clad laminate.
0), it was found that even after printing 5,000 sheets, the accuracy in the printed line was good and it had excellent printing durability.

Example 2 Average degree of polymerization 2000, degree of saponification 88.5 mol% Partially saponified polyvinyl alcohol (rPA-2 manufactured by Shin-Etsu Chemical Co., Ltd.)
0J), 20 parts of N-methylolacrylamide, 3.5-ditertiarybutyl-
4-Hydroxytoluene 0. , add part L and heat at 80℃ for 2 hours.
The reaction mixture was stirred for a period of time to obtain a photocrosslinkable polyvinyl alcohol derivative. Vinylidene chloride-methyl methacrylate-maleic anhydride fi polymerized separately by a conventional method
13-element m-coalescence aqueous emulsion [copolymerization ratio (mol) 85
:13:2, concentration 43%), 5 parts of polyoxyethylene nonylphenol ether, and 1 part of crystal violet dye were added and mixed to the above aqueous solution of N-methyloleacrylamidated polyvinylalkonoe to disperse a photosensitive resin composition. A liquid was prepared. 100% of this photosensitive dispersion
After applying the mixture to a mesh polyester screen plate using a packet, drying was repeated four times to form a photoresist film with a thickness of 20 μm.

Using the obtained photosensitive screen plate, a screen plate having a photographic image composed of 60 lines/inch and 50% halftone dots was prepared in the same manner as described in Example 1.

This printing plate and textile printing ink (manufactured by TW Graphics, USA, r15000 WATERBASE TE)
XTILI! 20 on a T-shirt using INKJ)
When 00 sheets were printed, a beautiful printed product was obtained, and it was found that the printing plate had no missing fine halftone dots and had excellent water resistance and adhesive strength to the screen mesh.

Example 3 Partially saponified polyvinyl alcohol with an average degree of polymerization of 1800 and a degree of saponification of 83.5 mol% (manufactured by Shin-Etsu Chemical @r LA-
18J) A mixture of 1000 parts of a 10% aqueous solution and 2 parts of acrylic acid was heated, and 50 parts of glycidyl methacrylate was gradually added dropwise thereto, and the mixture was reacted at 85°C for 2 hours.
An aqueous solution of a partially saponified polyvinyl alcohol grafted with glycidyl methacrylate was obtained. Separately, an aqueous emulsion of vinylidene chloride-2-hydroxyacrylate copolymer polymerized by a conventional method [copolymerization ratio (mol) 92
:8, concentration 50%] 280 parts, 3 parts of polyoxyethylene oleyl phenyl ether, and 10 parts of diazo resin were added and mixed to the above-mentioned glycidyl methacrylate ester grafted partially saponified polyvinyl alcohol solution to prepare a dispersion of the photosensitive composition. Prepared.

This photosensitive dispersion was applied to a polyester film with a thickness of 75 μl and dried with hot air at a temperature of 50°C, resulting in a dry film thickness of 30 μl.
A laminated film having a μm photosensitive film was produced.

When making a screen plate using this laminated film, place the laminated film on a flat plate with the photoresist side facing up, place the screen plate on top of it, and apply water to the screen surface using a sponge soaked in water. After applying it for 30 seconds, scrape off the excess coating water with a rubber squeegee and dry it with warm air to evenly paste the M scrap film on the screen plate.
The photoresist film can be embedded and fixed in the screen mesh.

During exposure, the polyester film was peeled off and the original positive film was brought into close contact with the completely smooth photoresist film surface for exposure.

Through these operations, a laminated film was pasted on a 270 mesh polyester screen plate, dried, exposed to light, developed with water, and dried. When printed on paper using "Vinitop"), 1
No damage to the plate was observed even after printing 0.000 sheets.

In addition, after exposing the laminated film for 2 minutes at a distance I1) using a 3KW metal halide lamp, the photoresist film was separated,
The results of measuring the water absorption rate and solubility in various solvents of the photocrosslinked photosensitive film are shown in Table 1 below. The results of similar measurements for the following comparative examples are also shown in Table 1.

Comparative Example 1 In the photosensitive resin composition dispersion of Example 3, vinyl acetate emulsion (
A laminated film was prepared in exactly the same manner as described in Example 3, except that Movinyl MA-6J (manufactured by Hoechst Synthesis) was used.The water absorption rate of the photosensitive film of this laminated film and the dissolution rate in various solvents were The measured results are shown in Table 1.

"Measurement method" Cut the water-absorbing greyish-colored light-crosslinked photosensitive film into a size of 10 nu+ x 30 m+ to use as a sample. Take 1g of sample and heat at 30℃
After soaking in 300 Ta 1 of water for 48 hours and lightly draining, centrifugally dehydrated by rotating at 3000 r, p, m in a centrifugal separator, weighing (W+), and then heating at 105°C for 4 The bone dry weight (Wo) after time drying is weighed and calculated using the following formula.

O Pandankuni Koka Identification Photocrosslinking Photosensitive Film l0III1) x 301) I1
) and use it as a sample. Take 1g of sample, 1
After drying at 05℃ for 4 hours, the weight f! Weigh k (W O). Next, this dry sample was heated at 30°C for 300m j! After 48 hours of immersion in an organic solvent of
).

W.

Procedural amendment 1. Display of case 1985 patent application No. 272591 2
, Title of the invention: Photosensitive resin composition 3, Relationship with the person making the amendment: Patent applicant name: Aicello Chemical Co., Ltd. 4, Agent address: Shinbashi Kokusai Building 5, 812-7-7 Higashishin, Minato-ku, Tokyo. The date of the amendment order is voluntary 6, the number of inventions increased by the amendment 8, and the description of the contents of the amendment is amended as follows.

1)) The scope of claims is amended as shown in the attached sheet.

(2) Page 6, line 1), after “poly (meth)acrylic acid or its salt,” “polyester (meth)acrylate, epoxy (meth)acrylate, urethane (meth)acrylate polymer or oligomer,” join.

(3) In lines 5 and 6 of page 7, "as long as the partially urethanized product has water solubility, an aqueous solution" is corrected to "water i8?ff<or an aqueous dispersion of the partially urethanized product, etc."

(4) Add "trimethylolpropane tri(meth)acrylate, tetramethylolmethanetetra(meth)acrylate" after "ethylene glycol diacrylate" on page 7, line 14.

(5) On page 7, line 16, after “Photo-crosslinkable single-walled materials may be used as examples,” “In addition, if the water-soluble polymeric substance and the photo-crosslinking agent are photopolymerizable substances, hensifhenone , it is necessary to use a polymerization initiator such as benzyl, anthraquinone, or thioxanthone.''

(6) On page 1t, lines 9 to 10, “preferably 40 to 40
70% by weight” should be replaced with “preferably 30 to 70% by weight”
and correct it.

(7) Page 13, line 6: “Can be added as appropriate.

'' followed by ``It can also be used in combination with other polymer emulsions such as polyvinyl acetate, polyvinyl chloride, and polystyrene.''

2. Scope of claims +1) (A) a water-soluble polymeric substance with a high water content and its photocrosslinking agent, or a water-soluble polymeric substance with a photocrosslinkable water content, and (B) vinylidene chloride and 1. A photosensitive resin composition comprising a copolymer containing (meth)acrylic acid and/or a (meth)acrylic acid derivative as a main copolymerization component as an active ingredient.

(2) The photosensitive resin composition according to claim (1), wherein the water-soluble polymeric substance is a polyvinyl alcohol resin.

(3) The copolymer has a vinylidene chloride copolymerization ratio of 60 to 95 mol%, preferably 70 to 90 mol%.
% by mole of the photosensitive resin composition according to claim (1).

(4) Claim (1) wherein the composition contains 20 to 80ffi1%, preferably average to 70% by weight of the copolymer.
The photosensitive resin composition described in .

Claims (4)

[Claims] (1) (A) A water-soluble polymer substance and its photocrosslinking agent, or a water-soluble polymer substance having photocrosslinkability, and (B) vinylidene chloride and (meth)acrylic acid and/or (meth)acrylic acid derivative 1. A photosensitive resin composition comprising, as an active ingredient, a copolymer having as a main copolymerization component. (2) The photosensitive resin composition according to claim (1), wherein the water-soluble polymeric substance is a polyvinyl alcohol resin. (3) The copolymer has a vinylidene chloride copolymerization ratio of 60 to 95 mol%, preferably 70 to 90 mol%.
% by mole of the photosensitive resin composition according to claim (1). (4) The photosensitive resin composition according to claim (1), which contains the copolymer in an amount of 20 to 80% by weight, preferably 40 to 70% by weight.