JPH04344647A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To make a printing plate for screen printing by using the photosensitive resin composition and to repeatedly form high-quality prints for a long period. CONSTITUTION:The photosensitive resin composition contains an aqueous polymer having film-forming ability, such as polyvinyl alcohol or polyvinyl acetate emulsion, a photosensitive agent, such as diazonium type compound, azido type compound, polyvinyl alcohol having stilbazolium groups, or a photopolymerizable photosensitive agent comprising an additionally polymerizable monomer and a photopolymerization initiator, and a fluorinated compound insoluble in water and alcohols and dispersed in water in <=5mum particle diameter in an amount of 0.1-30wt.% of the aqueous polymer in terms of the solid matter.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-developable photosensitive resin composition useful for obtaining printing plates for screen printing.

0002

[Prior Art and Problems to be Solved by the Invention] A composition containing polyvinyl alcohol and ammonium dichromate as a photosensitive resin composition for screen printing plates; a composition containing a vinyl acetate emulsion, polyvinyl alcohol and a diazo compound; A composition containing an acrylic monomer as an addition polymerizable monomer and a photopolymerization initiator to these compositions; A composition containing a vinyl acetate emulsion and a stilbazolated polyvinyl alcohol (Japanese Patent Publication No. 56
-40814) is known.

[0003] A screen printing plate is obtained by applying the photosensitive resin composition on a screen stretched over a predetermined frame, closely contacting the screen with a predetermined pattern, exposing the screen to ultraviolet rays, and developing the screen.

[0004] The obtained screen printing plate is brought into close contact with a printing material such as a substrate for screen printing, paper, printed wiring board, ceramics, plastic, glass, metal, etc., and the printing ink is scraped off from the back side using a squeegee. Printing is performed by

[0005] When printing repeatedly using the above-mentioned screen printing plate, although there is a demand for high-quality printed matter, the printing ink wraps around the surface of the plate, that is, the side of the printing material, causing the printed matter to deteriorate. Bleeding occurs on the lines. Particularly, in the case of thin lines, the above-mentioned phenomenon appears prominently, making it impossible to obtain high-quality printed matter. Such problems are caused by the high affinity between screen printing plates and printing ink.

[0006] JP-A No. 61-113064 proposes providing a coating layer with poor wettability with printed materials, such as a fluororesin coating layer, on the surface of the printing plate that comes into contact with the printed material. . However, since this method has a limited durability of the surface coating layer, the effectiveness of this method decreases significantly when printing is repeated. Furthermore, if a coating layer is formed on a region of the contact surface with the printing material other than the image area, the coating agent oozes into the image area, which tends to reduce the dimensional accuracy of the fine line area.

[0007] JP-A-2-144537 proposes adding an alcohol-soluble fluorine compound to a photosensitive resin composition. However, since fluorine-based compounds are alcohol-soluble, they are highly hydrophilic and cannot be used on printing plates in environments where they are affected by moisture, such as when printing under high humidity or when printing with water-based inks. durability is significantly impaired.

[0008] Accordingly, an object of the present invention is to provide a photosensitive resin composition that can repeatedly produce high-quality printed matter over a long period of time.

[0009]

[Structure of the Invention] As a result of intensive studies to achieve the above object, the present inventors have found that adding a water-dispersible fluorine compound to a photosensitive resin composition can prevent stains caused by printing ink and blurring of printing lines for a long period of time. The present invention was completed by discovering that it is possible to prevent cross-over and form thin wires with high accuracy.

That is, the present invention provides a photosensitive resin composition containing an aqueous polymer having film-forming ability, a photosensitizer, and a water-dispersible fluorine compound.

[0011] The water-based polymer includes water-soluble polymers and water-dispersible polymers. Preferably, the aqueous polymer comprises a water-soluble polymer. The water-soluble polymer becomes insolubilized in the exposed area. Examples of water-soluble polymers include polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, acrylic polymer, water-soluble nylon, polyvinylpyrrolidone,
Examples include casein and gelatin. At least one of these water-soluble polymers is used.

Among the water-soluble polymers, polyvinyl alcohol is preferred. As polyvinyl alcohol, the average degree of polymerization is 500 to 3000, preferably 1000 to 25.
00, degree of saponification 78-98 mol%, preferably 80
About 95 mol% of polyvinyl alcohol can be used. If the average degree of polymerization of polyvinyl alcohol is less than 500, the degree of insolubilization by the photosensitizer will be small, resulting in a decrease in mechanical strength and water resistance. If it exceeds 3000, the viscosity will be high, making coating difficult, as well as poor developability. decreases. Further, if the degree of saponification is less than 78 mol%, the developability and strength of the film will decrease, and if it exceeds 98 mol%, the reactivity with the photosensitive agent and the developability will decrease.

Examples of the water-dispersible polymer include various emulsions, such as polyvinyl acetate emulsion, ethylene-vinyl acetate copolymer emulsion, acrylic-vinyl acetate copolymer emulsion, and vinyl chloride-vinyl acetate copolymer emulsion. Examples include vinyl acetate emulsion, acrylic emulsion, ethylene-acrylic copolymer emulsion, styrene-acrylic copolymer emulsion, styrene-butadiene copolymer emulsion, vinyl chloride emulsion, and vinylidene chloride emulsion. Among these emulsions, vinyl acetate emulsions such as polyvinyl acetate emulsions are frequently used. Emulsions can be used singly or in combination of two or more.

Although the water-soluble polymer and water-dispersible polymer can be used alone, it is preferable to use them in combination. The ratio of the water-soluble polymer to the water-dispersible polymer is approximately 25-75:75-25 (wt%), preferably 30-70:70-30 (wt%), in terms of solid content. If the content of the water-soluble polymer is less than 25% by weight, developability etc. will be reduced, and if it exceeds 75% by weight, the degree of insolubilization by the photosensitive agent will be small, resulting in reduced water resistance and printing durability.

The photosensitizer includes conventional compounds such as diazo compounds, azide compounds, polyvinyl alcohol derivatives having a stilbene skeleton containing a nitrogen atom, as well as combinations of addition polymerizable monomers and photopolymerization initiators. It also includes photopolymerizable photosensitizers.

Examples of diazo compounds include diazonium salts, tetrazonium salts, polydiazonium salts, p
Examples include diazo resin, which is a condensate of -diazodiphenylamine and formaldehyde. Examples of the azide-based compound include monoazide compounds, diazide compounds, polyazide compounds, and polymers into which azide groups are introduced, such as poly(vinyl azidobenzoate). Examples of polyvinyl alcohol derivatives having a stilbene skeleton containing a nitrogen atom include polyvinyl alcohol derivatives having a styrylquinolinium group, a stilbazolium group, etc. Public notices, etc.). The nitrogen atom of the stilbene skeleton of the polyvinyl alcohol derivative is usually alkylated and forms a salt.

The addition polymerizable monomer constituting the photopolymerizable photosensitizer includes various compounds having an α,β-ethylenically unsaturated group, such as acrylamide, methyl acrylate, ethyl acrylate, and butyl acrylate. acrylates such as N,N'-methylenebisacrylamide, N,N'-
Benzylidene bisacrylamide, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 1,4- Butanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 2
, 2-bis(4-acryloyldiethoxyphenyl)propane, diacrylate of ethylene oxide adducts of bisphenol A such as 2,2-bis(4-acryloylpentaethoxyphenyl)propane, 2,2-bis(
4-acryloyldipropoxyphenyl)propane, 2
, diacrylates of propylene oxide adducts of bisphenol A such as , 2-bis(4-acryloylpentapropoxyphenyl)propane, glycerin triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexa This includes acrylates and their corresponding methacrylates. In addition, addition polymerizable monomers include, for example,
Epoxy acrylate, oligoester acrylate,
Also included are urethane acrylates and the corresponding methacrylates. These addition polymerizable monomers can be used alone or in combination of two or more.

As the photopolymerization initiator, conventional compounds such as benzoins such as benzoin; benzoin ethers such as benzoin methyl ether and benzoin ethyl ether; benzophenone, 4,4'-bis(dimethylamino)benzophenone, , 4'-bis(diethylamino)benzophenone and other benzophenones and their derivatives; quinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-chloroanthraquinone, 1,4-naphthaquinone, 9,10-phenanthraquinone; Thioxanthone such as thioxanthone, 2-chlorothioxanthone, and 2-ethylthioxanthone; Sulfide compounds such as 4-benzoyl-4'-methyldiphenyl sulfide and 4-benzoyl-4'-ethyldiphenyl sulfide; 2,4,5-tria Examples include rylimidazolyl dimer; oxime esters such as benzophenone oxime acetate; α,α-diethoxyacetophenone, benzyl, and benzyl dimethyl ketal. The photopolymerization initiators can be used alone or in combination of two or more. The photopolymerization initiator is a sensitizer, for example, a dye sensitizer such as a triarylmethaneleuco dye; an alkylaminobenzoic acid such as methyl p-(dimethylamino)benzoate or ethyl p-(dimethylamino)benzoate; May be used in combination with ester.

These photosensitizers can be used alone or in combination of two or more.

Generally, as the content of the photosensitizer increases, the degree of insolubilization of the film in the exposed area increases, and the mechanical strength, solvent resistance, water resistance, and printing durability increase. The upper limit of can be selected depending on the desired printing durability and the like. The content of the photosensitizer is, for example, 1 to 20 parts by weight based on 100 parts by weight of the aqueous polymer in terms of solid content, excluding the polyvinyl alcohol derivatives and photopolymerizable photosensitizers having a stilbene skeleton containing a nitrogen atom. , preferably about 5 to 15 parts by weight. If the amount of the photosensitive agent is less than 1 part by weight, the degree of insolubilization of the aqueous polymer will be low, and if it exceeds 20 parts by weight, uniform coating may become difficult.

[0021] When using a polyvinyl alcohol derivative having a stilbene skeleton containing a nitrogen atom, this polyvinyl alcohol derivative also functions as a water-soluble polymer having film-forming ability. Not necessary. A polyvinyl alcohol derivative having a stilbene skeleton containing a nitrogen atom is usually used in combination with a water-dispersible polymer. In this case, the amount of the polyvinyl alcohol derivative having a stilbene skeleton containing a nitrogen atom used is, for example, about 5 to 200 parts by weight, preferably about 15 to 100 parts by weight, based on 100 parts by weight of the water-dispersible polymer.

The addition amount of the addition-polymerizable monomer is, for example, 1 to 1 part by weight per 100 parts by weight of the aqueous polymer in terms of solid content.
00 parts by weight, preferably 5 to 75 parts by weight, more preferably 10 to 50 parts by weight.

The amount of the photopolymerization initiator added is, for example, about 0.1 to 30 parts by weight, preferably about 1 to 25 parts by weight, based on 100 parts by weight of the addition polymerizable monomer.

The water-dispersible fluorine compound is an emulsion in which a fluorine compound insoluble in water or alcohols is dispersed in water. The type of fluorine-based compound is not particularly limited as long as it is insoluble in water and alcohol. Examples include merging. Examples of the fluorine-based monomer include chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, vinyl fluoride, and vinylidene fluoride. Fluorine compounds are
It may also be a copolymer of the fluorine-based monomer and a copolymer component such as ethylene. The fluorine-based compound is preferably a low molecular weight polymer containing the above-mentioned fluorine-based monomer as a constituent monomer. Specific examples of fluorine-based compounds include, for example, an emulsion-type water and oil repellent containing a fluorine-based compound [manufactured by Asahi Glass Co., Ltd., trade name: Asahi Guard AG-
710, AG-730, AG-740, AG-780,
AG-800, Surflon S-112, etc.], water and oil repellent [manufactured by Sumitomo 3M, trade name: Fluorad (Fluo
rad) FC-725, FX-3325, etc.]. These fluorine compounds can be used alone or in combination of two or more.

[0025] The fluorine compound is added to the photosensitive film at a concentration of 10 µm in order to prevent oil spots from being formed due to repellency.
m or less, preferably 5 μm or less.

The content of the water-dispersible fluorine compound is, for example, 0.1 to 30 parts by weight, preferably 0.5 to 25 parts by weight, more preferably 0.5 to 25 parts by weight, based on 100 parts by weight of the aqueous polymer, in terms of solid content. is about 1 to 20 parts by weight. If the content of the water-dispersible fluorine-based compound is less than 0.1 part by weight, the precision of fine lines on printed matter tends to decrease due to bleeding during printing, and if it exceeds 30 parts by weight, the water resistance of the photoresist film will be significantly reduced during development. Sexuality tends to decrease.

The photosensitive resin composition of the present invention may optionally contain an antifoaming agent, a leveling agent, a coloring agent, an antistatic agent, and an organic solvent such as alcohol.

The photosensitive resin composition of the present invention can be used as a variety of image-forming compositions, and is suitable for obtaining printing plates for screen printing. A screen printing plate can be obtained as follows. Silk in the frame
The screen is formed by stretching gauze cloth made of polymers such as nylon, Tetron, polyester, and metals such as stainless steel. A photosensitive resin composition is applied to this screen and dried to form a photosensitive film. The photosensitive film may be formed by coating a photosensitive resin composition on a film, drying it, transferring it to the screen, and bonding the film. Next, a negative pattern is brought into close contact with the photoresist film, and the photoresist film is exposed to ultraviolet light to insolubilize the exposed portions of the photoresist film. Then, by removing the photoresist film in unexposed areas with water and developing it, a printing plate for screen printing is obtained.

[0029]

Effects of the Invention Since the photosensitive resin composition of the present invention contains a water-dispersible fluorine compound, high-quality printed matter can be repeatedly obtained over a long period of time.

[0030]

EXAMPLES The present invention will be explained in more detail below based on Examples, but the present invention is not limited to these Examples.

Comparative example 1 The following components were mixed to prepare a photosensitive resin composition.

Polyvinyl alcohol (10% by weight aqueous solution)
100 parts by weight polyvinyl acetate emulsion (solid content 50% by weight)
20 parts by weight diazo resin (10% by weight aqueous solution)
20 parts by weight The average degree of polymerization of polyvinyl alcohol is 2000, and the degree of saponification is 88 mol%. Moreover, the diazo resin obtained by condensing p-diazodiphenylamine hydrochloride and paraformaldehyde in the presence of sulfuric acid was used.

The obtained photosensitive resin composition was applied onto a screen and dried to form a photosensitive film having a thickness of 10 μm. Next, a predetermined pattern was adhered to the photoresist film and exposed to ultraviolet rays, and then water was sprayed and developed to obtain a screen printing plate.

Example 1 50 parts by weight of a fluorine compound [manufactured by Sumitomo 3M, trade name Fluorad FC-725, solid content 30% by weight] was mixed with 5 parts by weight of water.
0 parts by weight, and the fluorine-based compound was emulsified and dispersed to a particle size of 1 to 5 μm using a homogenizer.

10 parts by weight of this dispersion were added and mixed with 140 parts by weight of the composition prepared in Comparative Example 1 to prepare a photosensitive resin composition. The content of the fluorine compound in the photosensitive resin composition is 7.5 parts by weight based on 100 parts by weight of the aqueous polymer. Then, in the same manner as in Comparative Example 1, a thickness of 10
A .mu.m photosensitive film was formed, exposed and developed to obtain a screen printing plate.

Example 2 50 parts by weight of a fluorine compound [manufactured by Sumitomo 3M, trade name Fluorad FX-3325, solid content 10% by weight] was added to 50 parts by weight of water, and the fluorine compound was heated to a particle size of 1 by using a homogenizer. It was dispersed and emulsified to ~5 μm.

Five parts by weight of this dispersion were added and mixed with 140 parts by weight of the composition prepared in Comparative Example 1 to prepare a photosensitive resin composition. The content of the fluorine compound in the photosensitive resin composition is about 1.3 parts by weight based on 100 parts by weight of the aqueous polymer. A screen printing plate was prepared in the same manner as in Comparative Example 1, except that this photosensitive resin composition was applied and dried on a polyester film, and the photosensitive film was transferred to a screen and bonded to form a 10 μm thick photosensitive film. Obtained.

Comparative example 2 The following components were mixed to prepare a photosensitive resin composition.

Polyvinyl alcohol having styrylquinolinium group (7% by weight aqueous solution)

100 parts by weight polyvinyl acetate emulsion (
Solid content 50% by weight) 23 parts by weight
Pentaerythritol triacrylate
6 parts by weight benzyl dimethyl ketal (photopolymerization initiator)
1 part by weight Polyvinyl alcohol having a styrylquinolinium group is
According to the method described in Publication No. 61, the average degree of polymerization was 20.
00, 2.5 mol% of styrylquinolinium groups were introduced into polyvinyl alcohol with a degree of saponification of 88 mol%.

The obtained photosensitive resin composition was coated on a polyester film and dried, and the photosensitive film was transferred to a screen and bonded to form a photosensitive film with a thickness of 15 μm.
A screen printing plate was obtained in the same manner as in Comparative Example 1.

Example 3 Emulsion containing fluorine compound [manufactured by Asahi Glass Co., Ltd.]
Product name Asahi Guard AG-710, solid content 18% by weight]
15 parts by weight were added and mixed to 130 parts by weight of the composition prepared in Comparative Example 2 to prepare a photosensitive resin composition. The content of the fluorine compound in the photosensitive resin composition is about 14.5 parts by weight based on 100 parts by weight of the aqueous polymer. The photosensitive resin composition was applied onto the screen and dried to a thickness of 15 μm.
A screen printing plate was obtained in the same manner as in Comparative Example 1 except that the photosensitive film was formed.

Example 4 Emulsion containing a fluorine compound [manufactured by Asahi Glass Co., Ltd.]
Product name Surflon S-112, solid content 15% by weight] 10
Parts by weight were added to 130 parts by weight of the composition prepared in Comparative Example 2 to prepare a photosensitive resin composition. The content of the fluorine compound in the photosensitive resin composition is 10% of the aqueous polymer.
It is about 8 parts by weight compared to 0 parts by weight. A screen printing plate was obtained in the same manner as in Comparative Example 1, except that the photosensitive resin composition was applied and dried on a polyester film, and the photosensitive film was transferred to a screen and bonded to form a 15 μm thick photosensitive film. Ta.

Comparative Example 3 In place of 10 parts by weight of the fluorine compound dispersion used in Example 1, an alcohol-soluble fluorine compound [manufactured by Asahi Glass Co., Ltd., trade name Surflon S-111, solid content concentration 30% by weight] was used. ] In the same manner as in Example 1 except for using 5 parts by weight,
A printing plate for screen printing was obtained. The content of the fluorine compound in the photosensitive resin composition is 7.5 parts by weight based on 100 parts by weight of the aqueous polymer.

Using the screen printing plates obtained in Examples 1 to 4 and Comparative Examples 1 to 3, 10,000 sheets were printed using screen printing ink at a temperature of 25° C. and a humidity of 80% RH. did. The degree of staining on the plate and blurring of the image line with the number of prints was investigated, and the results shown in the table were obtained. The degree of staining of the plate and the degree of blurring of the image lines were evaluated based on the following criteria.

Excellent: No stains or smudges Good: Slight stains or bleeds are observed. Impossible: Significant dirt or bleeding

[0046]

[Table 1] From the table, in the screen printing plates of Examples 1 to 4, stains on the plate and blurring of the image lines are significantly reduced compared to the plates of Comparative Examples 1 to 3.

Claims (2)

[Claims] 1. A photosensitive resin composition containing an aqueous polymer having film-forming ability, a photosensitizer, and a water-dispersible fluorine compound. 2. The photosensitive resin composition according to claim 1, which contains, in terms of solid content, 0.1 to 30 parts by weight of a water-dispersible fluorine compound per 100 parts by weight of the aqueous polymer.