JPH04147146A - Photosensitive film for screen plate making - Google Patents

Abstract

PURPOSE:To improve the water resistance, the solvent resistance and the plate wear by forming a specified printed surface layer on a base film and having a structure laminated an adhesion supporting layer on it. CONSTITUTION:The film has such a structure that a composition A layer as the printed surface layer is formed on the base film and a composition B layer as the adhesion supporting layer is laminated on it. The composition A layer is a photosensitive resin composition of (a) polyvinyl alcohol or polyvinal alcohol derivatives, (b) a photopolymerized monomer having an ethylene type unsaturat ed bond in the molecule and a photoinitiator, (c) a photocrosslinking agent, and (d) fine powders of a polyethylene type polymer having >= 100 deg.C of a softening point, 1-20 mum of a particle size and 0.92 in the density, etc. The composition B layer is a photosensitive resin composition layer consisting of the components (a)-(c) and further (e) a hydrophobic high polymer emulsion. Thus the plate releasing property, the water resistance and the solvent resistance are improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a coating film that can be developed with water, has excellent water resistance and solvent resistance, and can be printed with water-based inks, water-based pressure-sensitive adhesives, etc. The present invention relates to the obtained photosensitive material for screen plate making.

[Conventional technology]

Screen printing has the characteristics of easy plate making and printing, high image accuracy, large thickness of printed ink, and can be used on any substrate, and is used in a wide variety of fields. Its uses are still expanding, from printing textiles and posters to printing solder resists and etching resists used in the production of printed circuit boards. As screen printing plates are used in the production of printed circuit boards, performance requirements have increased in recent years, and in addition to water resistance, solvent resistance, and abrasion resistance, higher precision and excellent printability are required. It became so.

Furthermore, water-based inks that do not contain organic solvents have come to be used due to issues such as occupational health and pollution, and membrane switches have been introduced to various electronic devices, and water-based pressure-sensitive adhesives have been used for their spacers. Since the coating is also performed by screen printing, the screen printing plate is required to have a high degree of water resistance.

Conventionally, the mainstream screen-making method has been a method called a direct method in which a photosensitive resin is directly coated on gauze. However, although this direct method allows the desired film thickness to be obtained by overcoating, it not only has the drawback of extremely poor workability as it requires repeated application and drying of the photosensitive resin. Since the smoothness of the resin film surface is poor, printing reproducibility is poor due to ink bleeding, etc. Therefore, it is becoming difficult to meet the currently required printing suitability and accuracy. As a screen plate making method that improves the drawbacks of the direct method as described above, a photosensitive composition is coated on a base film and dried to form a photosensitive film for screen plate making, and the film is mixed with water or a photosensitive composition. A method called the film method was discovered, in which a plate is formed by pasting the paper onto gauze using a material, and then peeling off the hese film after drying. By using this film method, the work process can be shortened and a coating film of uniform thickness can be obtained on the screen print, making it possible to obtain plates with excellent precision. A plate-making film that can be printed and has excellent water resistance and solvent resistance has not been found.

[Problem that the invention seeks to solve]

Conventional photosensitive resin compositions for screen plate making, regardless of whether the direct method or film method is used, have insufficient printing accuracy, water resistance, and solvent resistance, and may swell or dissolve. Stickiness occurs on the plate.

In addition, plates made using conventional film methods have insufficient water resistance and the smoothness of the plate film is excessively high, so that when the plate film swells with water, it completely adheres to the printing material. It has the disadvantage of being unsuitable for printing with water-based pressure-sensitive adhesives. That is, polyvinyl alcohol is used as a film-forming component in photosensitive resin compositions for screen plate making that have been commonly used. Even if this polyvinyl alcohol is crosslinked with a photosensitizer such as a diazo resin, it has many hydrophilic groups and therefore swells with polar water, alcohol, etc. When polyvinyl alcohol, which is a film-forming component, swells, not only the strength of the film decreases, but also tackiness develops on the surface of the film, the adhesion between the gauze and the plate film decreases, and the stiffness resistance significantly decreases.

To solve this problem, some direct method photosensitive resin composition liquids have an extremely reduced proportion of polyvinyl alcohol, but the direct method plate made from this photosensitive resin composition liquid is It has extremely poor water developability, takes a long time to develop, and also has problems with accuracy. The cause of this is an excess of hydrophobic polymer emulsion. Although hydrophobic polymer emulsion improves water resistance, if it is too much, emulsions will aggregate, significantly worsening water developability and causing clogging. This reduces accuracy by causing

In the case of non-polar solvents, the vinyl acetate emulsion added to improve water resistance dissolves or swells, resulting in tackiness and reduced adhesion to the gauze, resulting in a significant decrease in printing durability. .

[Means to solve the problem]

The present inventors have made extensive studies to solve the above-mentioned problems, and have completed the present invention. The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and in particular to enable printing with water-based inks and water-based pressure-sensitive adhesives, so that the printing surface has an appropriate roughness, has water resistance, solvent resistance, An object of the present invention is to provide a photosensitive material for screen plate making that has excellent rigidity resistance.

As a result of intensive research to solve these problems, in a photosensitive film for screen plate making, a printing surface layer (composition A layer) is formed on the base film, and an adhesive support layer (Bill composition layer) is formed on the base film. We have found a water-developable photosensitive film for screen plate making which is characterized by having a laminated structure. The components of the printing surface layer (A composition layer) and the adhesive support layer (B&Il composition N) are shown below.

A composition layer = (a) polyvinyl alcohol or polyvinyl alcohol derivative, (a) photopolymerizable polymer 1 having an ethylenically unsaturated bond in the molecule and a photopolymerization initiator,
(c) Photocrosslinking agent, (d) Softening point 100°C or higher, particle size 1
~20 μm, a photosensitive resin composition layer consisting of a fine powder of polyethylene polymer with a density of 0.92 or more, a fine powder of tetrafluoroethylene resin with a particle size of 1 to 20 μm, or a mixture of these two types of fine powder. .

B composition layer: (a) polyvinyl alcohol or polyvinyl alcohol derivative) a photopolymerizable monomer having an ethylenically unsaturated bond in the molecule, and a photopolymerization initiator,
A photosensitive resin composition layer comprising (c) a photocrosslinking agent and (e) a hydrophobic polymer emulsion.

The printed surface layers of the film of the present invention are (a), (b), (
The water resistance of the photosensitive resin composition is improved by using a spherical polyethylene polymer or tetrafluoroethylene resin, which has excellent water resistance and solvent resistance, as the component (d). In addition to improving the solvent resistance, it is possible to form appropriate irregularities on the surface of the film to prevent it from adhering to the printing material. A spherical shape is preferable in order to prevent the printed material from being scratched when the added fine powder of polyethylene polymer or tetrafluoroethylene resin is exposed on the film surface.

If the particle size of the fine powder of these polyethylene polymers or tetrafluoroethylene resins is less than 1 μm, the particle size is small and it is not possible to form appropriate irregularities on the membrane surface. Also, 20 μ-
The above is unsuitable because the particle size is large, resulting in poor resolution, and the plate surface is too rough, resulting in ink smearing.

In addition, the polyethylene polymer fine powder to be added is limited to a softening point of 100"C or higher.A softening point of 100"C or higher.
If it is less than that, the polyethylene polymer fine powder will be softened in the drying process when forming the photosensitive resin composition into a film.
Appropriate unevenness cannot be formed on the film surface. Also, the density is 0.
Polyethylene polymers with a molecular weight of less than 92 are undesirable because they swell significantly with solvents.

On the other hand, tetrafluoroethylene resin has a melting temperature of approximately 300°C.
There are no problems with the drying process, and it has excellent water resistance and solvent resistance.

However, the softening point is 100℃ or more, the particle size is 1 to 20〃
Addition of a spherical polyethylene polymer with a m density of 0.92 or more or a fine powder of tetrafluoroethylene resin has the disadvantage that it slightly weakens the film strength of the photosensitive resin film and lowers the adhesive strength with the gauze. The adhesive support layer of the present invention is made of polyvinyl alcohol or a polyvinyl alcohol derivative, a photopolymerized material having an ethylenically unsaturated bond in the molecule. Shokotsumar and photopolymerization initiator, photocrosslinking agent,
By coating a photosensitive resin composition consisting of a hydrophobic polymer emulsion, water resistance and solvent resistance can be achieved that prevents adhesion to the printing material without reducing film strength or adhesion to the gauze. A photosensitive film for screen plate making with excellent properties can be obtained.

The printing surface layer containing fine powder of polyethylene polymer or tetrafluoroethylene resin is coated with a thickness of 10 to 40μ steel, and the adhesive support layer that does not contain fine powder of polyethylene polymer or tetrafluoroethylene resin is coated with a thickness of 10 to 200μ. A range of thicknesses is preferred.

If the printing surface layer containing fine powder of polyethylene polymer or tetrafluoroethylene resin has a thickness of 40μ or more, the exposure time becomes extremely long due to the poor light transmittance of the polyethylene polymer or tetrafluoroethylene resin. This reduces practicality.

In addition, if the adhesive support layer that does not contain fine powder of polyethylene polymer or tetrafluoroethylene resin is less than 10μ, the strength of the plate film after exposure will be weakened and cracks will occur, making it difficult for the plate to have sufficient rigidity. is not obtained.

The polyvinyl alcohol and polyvinyl alcohol derivatives account for 5 to 70% of the total solid content, preferably 5 to 50% of the total solid content.
Use within a range of %. If it is less than 5%, water developability will be poor, and if it is more than 70%, water resistance will be poor.

Specific examples of the photopolymerizable monomers having ethylenically unsaturated bonds include pentaerythritol (meth)acrylate, dipentaerythritol hexa(meth)acrylate, tetramethylolmethane tri(meth)acrylate, and trimethylolpropane tri(meth)acrylate. ) acrylate, neopentyl glycol di(meth)acrylate, dibromneopentyl glycol di(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2
-Hydroxyethyl (meth)acryloyl phosphate, dicyclopentanyl diacrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-ethylhexyl (meth)acrylate, glycidyl (meth)acrylate, phenylglycidyl ( Examples include meth)acrylate, ethylene glycol diglycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N-methylol(meth)acrylamide, (meth)acrylamide, methylenebis(meth)acrylamide, and the like. The above "(meth)acrylate" means either methacrylate or acrylate. These photopolymerizable polymers having ethylenically unsaturated bonds have a total solid content of 0.
It is used in a range of 5 to 80%, preferably 5 to 70%.

If it is less than 0.5%, a plate with sufficient physical properties cannot be obtained, and if it is more than 80%, the product lacks storage stability.

As a photopolymerization initiator for the photopolymerizable monomer having an ethylenically unsaturated bond, acetophenone, benzophenone, benzoyl methyl ether, pensoyl propyl ether, Michler's ketone, di-t-butyl anthraquinone, 2-chlorothioxanthone, 2, Thioxanthone derivatives such as 4-dimethylthioxanthone are used. These may be used alone or in a mixture of two or more, if necessary, and the addition side is preferably 0.1 to 15 parts, more preferably It is used in a range of 0.5 to 10 parts.

Examples of the photocrosslinking agent for polyvinyl alcohol or polyvinyl alcohol derivatives include diazo resins and the like.

For this purpose, water-soluble diazo resins of anionic complexes such as sulfates and phosphates of p-diazodiamine paraformaldehyde condensates, and zinc chloride double salts can be used. Diazo resins of this type include paraamino diphenylamine, 4-amino-4'-methyldiphenylamine, 4-amino-4'-methoxydiphenylamine, 4-amino-4
A water-soluble diazo resin obtained by condensing a diphenylamine diazo compound such as '-nitrodiphenylamine with an aldehyde such as paraformaldehyde or acetaldehyde can be used. These photocrosslinking agents are used alone or in combination, and are used in an amount of 0.5 to 15 parts, preferably 1 part based on the total solid content.
-15 parts. If it is less than 0.5 parts, a photosensitive film with sufficient water resistance cannot be obtained, and if it is more than 15 parts, it takes too long to cure.

The fine powder of the spherical polyethylene polymer or tetrafluoroethylene resin having a softening point of 100° C. or higher, a particle size of 1 to 20 μM, and a density of 0.92 or higher accounts for 1 to 90% of the total solid content, preferably 5 to 70% of the total solid content. Used within the range of %.

If it is less than 1%, sufficient physical properties cannot be obtained, and if it is more than 90%, resolution and precision are adversely affected, and the light transmittance of the fine powder itself is poor, resulting in a long curing time.

Specific examples of the hydrophobic polymer emulsion in the photosensitive resin composition used for the adhesive support layer include vinyl acetate polymer emulsion, ethylene-vinyl acetate copolymer emulsion, silicone resin emulsion, and styrene-acrylic acid copolymer emulsion. Examples include polymer emulsions, acrylic acid emulsions, vinyl chloride polymer emulsions, vinylidene chloride polymer emulsions, and the like. These hydrophobic polymer emulsions are used in a range of 0.5 to 95%, preferably 5 to 70% of the total solid content. At 0.5%, the plate lacks water resistance, and at 95%, the product lacks storage stability.

As the base film, polyester film, polypropylene film, polyvinyl chloride film, acetate film, etc. are used.

On this base film, a printing surface layer shown as the composition layer described above and then an adhesive support layer shown as the composition layer B are coated and dried and laminated to form the photosensitive film for screen plate making of the present invention. get.

In addition to the components described above, the photosensitive film for screen plate making of the present invention may further contain dyes, pigments,
Plasticizers, coating properties improvers, etc. can be added.

The photosensitive film for plate making of the present invention is pasted on a screen printing plate covered with gauze using water or hydrous alcohol, dried, and the base film is peeled off to form a screen printing plate with a photosensitive film. . Then, an image mask is applied to this printing plate, and it is set in a vacuum printing frame, exposed to light using a metal halide lamp, etc., and developed using water.

Using the obtained plate, water-based ink, water-based pressure sensitive adhesive, etc. are printed on plastic film, plastic board, paper, etc.

〔Effect of the invention〕

By using the photosensitive two-layer film for screen plate making of the present invention described above, water-based ink containing a polar solvent,
Even in the case of printing with a water-based pressure-sensitive adhesive, a screen printing plate can be obtained that prevents close contact with the printing material and has excellent plate release properties, water resistance, and solvent resistance.

Example 1 Partially saponified polyvinyl alcohol with saponification degree of 88 mol% and polymerization degree of 1800 (“PlB, +” manufactured by Shin-Etsu Chemical Co., Ltd.)
Dissolve 40 g in 300 g of water, 30 g of neopentyl glycol cyacrylene (manufactured by Nippon Shokubai Chemical Co., Ltd.), 1.2 g of benzoyl isopropyl ether, high-density polyethylene (manufactured by Mitsubishi Chemical Corporation, JVO70S J density 0.967, Softening point: 131°C) is crushed to a particle size of 1
40g of fine powder classified from ~3 μm, 4-amino-
A photosensitive resin composition (^) is prepared by stirring and mixing 20 g of a condensate of 4'-methyldiphenylamine and paraformaldehyde.
was prepared.

Partially saponified polyvinyl alcohol with saponification degree of 88 mol% and polymerization degree of 1800 (Shin-Etsu Chemical rP-183) 40
g in 250 g of water, 30 g of neopentyl glycol diacrylate (manufactured by Nippon Shokubai Chemical Co., Ltd.), 1.2 g of benzoyl isopropyl ether, and ethylene vinyl acetate copolymer emulsion (manufactured by Sumitomo Chemical @) "Sumikaflex 400". ) Bog, condensate of 4-amino-4'-methyldiphenylamine and paraformaldehyde 20
A photosensitive resin composition (B) was prepared by stirring and mixing g.

Coat 15μ of the photosensitive resin composition (^) on the polyester film, and then apply the photosensitive resin composition (B) on top of it.
A 40 uts film for screen plate making was prepared by coating the film with a thickness of 25 μm.

This film was attached to a screen printing plate covered with a 150 mesh polyester film gauze using a mixed solution of water:isopropyl alcohol=8=2 and dried. When the polyester film was peeled off after drying, the thickness of the photosensitive film was 20 μm. This plate was covered with an image mask having a line width of 200 μm, set in a vacuum printing frame, and exposed for 180 seconds using a 3 kW metal halide lamp from a distance of 1 m.

Next, it was immersed in water at 20° C. for 2 minutes, developed completely with water spray, and dried. Using this plate, 10,000 sheets of water-based pressure-sensitive adhesive were printed on polyester film.
No problems arose.

Example 2 Partially saponified polyvinyl alcohol with saponification degree of 88 mol% and polymerization degree of 1800 (“P-18” manufactured by Shin-Etsu Chemical Co., Ltd.)
Dissolve 40 g in 300 g of water, add 30 g of neopentyl glycol diacrylate (manufactured by Nippon Shokubai Chemical Co., Ltd.), 1.2 g of benzoyl isopropyl ether, and tetrafluoroethylene resin (Nidoflon PTFEJ, manufactured by Nitto Electric Kogyo Co., Ltd.).
) was pulverized and classified into steel particles with a particle size of 1 to 3 μm, 40 g of fine powder, and 20 g of a condensate of 4-amino-4'-methyldiphenylamine and rose formaldehyde were stirred and mixed to form a photosensitive resin composition (A). Prepared. 20 μm of photosensitive resin composition (8) was coated on the polyester film, and then the same photosensitive resin composition (B) as in Example 1 was coated on top of the photosensitive resin composition (8).
An 80 μm screen plate making film was prepared by coating the film with a thickness of 60 μm.

This film was attached to a screen printing plate covered with a 150 mesh polyester film gauze using a mixed solution of water:isopropyl alcohol=8:2 and dried.

After drying, the polyester film was peeled off and the thickness of the photosensitive film was 60 μW. This plate has a line width of 500μ
A 3 kW metal halide lamp was applied to the film, and the film was exposed to light from a distance of 1 m for 5 minutes using a 3 kW metal halide lamp.

Next, it was immersed in water at 20° C. for 2 minutes, and then completely developed with water spray and dried.

Using this plate, 10,000 sheets of water-based pressure-sensitive adhesive were printed on polyester film without any problems.

Example 3 Partially saponified polyvinyl alcohol with saponification degree of 88 mol% and polymerization degree of 1800 (“P-18” manufactured by Shin-Etsu Chemical Co., Ltd.)
Dissolve 40g in 350g of water to obtain 1-methyl-4-(p-
Acetalization reaction is carried out by adding 1.2 mol % of (formylstyl) pyridinium per mole of structural unit of partially saponified polyvinyl alcohol and 0.15 N of phosphoric acid as an acid catalyst. After the reaction, hydroxylation is carried out. Neutralized using sodium. To this reaction solution were added 60 g of vinyl acetate polymer emulsion ("Movinyl 50M" manufactured by Hoechst Gosei ■, solid content 50%), 30 g of polyester acrylate ("Aronix 8100" manufactured by Toagosei ■), 0 g of t-butylperoxycarbonylbenzophenone. A photosensitive resin composition (B) was prepared by stirring and mixing . Product (B) was coated with 65 μm to prepare an 80 μm film for screen plate making.

This film was attached to a screen printing plate covered with a 150 mesh polyester film gauze using a mixed solution of water:isopropyl alcohol=8:2 and dried.

After drying, the polyester film was peeled off and the thickness of the photosensitive film was 60 μm. This plate has a line width of 500μ
A closed image mask was applied, the film was set in a vacuum printing frame, and it was exposed for 60 seconds with a 3 kW metal halide lamp from a distance of 1 m.

Next, it was immersed in water at 20° C. for 2 minutes, completely developed with water spray, and dried.

Using this plate, 10,000 sheets of water-based pressure sensitive adhesive were printed on polyester film without any problems.

Example 4 Partially saponified polyvinyl alcohol with a degree of saponification of 88 mol% and a degree of polymerization of 18,000 (rP-18J manufactured by Shin-Etsu Chemical Co., Ltd.)
) was dissolved in 350 g of water to obtain 1 methyl-4-(p
-formylstyl)pyridinium in an amount of 1.2 mol % per mol of the structural unit of partially saponified polyvinyl alcohol and 0.15 N of phosphoric acid as an acid catalyst to carry out an acetalization reaction, and after the reaction, water Neutralized using sodium oxide. Add high-density polyethylene (
"JvO70S" manufactured by Mitsubishi Chemical Corporation, density 0.967
, softening point: 131°C) and classified into particles with a particle size of 1 to 3 μm, 40 g, and 30 g of polyester acrylate (manufactured by Toagosei ■ [Aronix 8] 00J).
, t-butylperoxycarbonylbenzophenone 0.
A photosensitive resin composition (8) was prepared by stirring and mixing 4 g. Photosensitive resin composition (8) on polyester film
was coated with a thickness of 15 μm, and then a photosensitive resin composition (B) similar to that of Example 3 was coated with a thickness of 15 μm to prepare a 30 μm film for screen plate making.

This film was attached to a screen printing plate covered with a 150 mesh polyester film gauze using a mixed solution of water and isobrobyl alcohol (8:2) and dried. After drying, the polyester film was peeled off and the thickness of the photosensitive film was 10 μm. Apply an image mask with a line width of 100 μm to this plate, set it in a vacuum printing frame, and set it at a distance of 1 m.
Exposure was performed for 40 seconds using a 3 kW metal halide lamp. Next, it was immersed in water at 20° C. for 2 minutes, completely developed with water spray, and dried.

This plate was used to print 10,000 sheets of water-based pressure sensitive adhesive on polyester film without any problems.

Comparative Example 1 A 40 μ chain film for screen plate making was prepared by excluding the A layer of Example 1 and using the B layer.

This film was attached to a screen plate covered with 150 mesh polyester gauze using a mixed solution of water and isopropyl alcohol (8:2) and dried. After drying, the polyester film was peeled off and the thickness of the photosensitive film was 20 μm.

An image mask with a line width of 200 μm was applied to this plate, it was set in a vacuum printing frame, and exposed for 180 seconds using a 3 kW metal halide lamp from a distance of 1 m. Next, it was immersed in water at 20°C, developed completely with water spray, and dried.

When this plate was used to print a water-based pressure-sensitive adhesive on a polyester film, the plate swelled after about 100 copies and the plate began to adhere to the printing material, and after 250 copies were printed, the photosensitive film peeled off from the gauze. At first it became impossible to print.

Comparative Example 2 A photosensitive resin composition having the same composition as in Comparative Example 1 was coated on a screen plate covered with 150 mesh polyester gauze using a packet to form a 20 μm photosensitive film. This plate was covered with an image mask having a line width of 200 μm, set in a vacuum printing frame, and exposed for 180 seconds with a 3 kW metal halide lamp from a distance of 1 m. Next, it was immersed in water at 20°C, developed completely with water spray, and dried.

When this plate was used to print a water-based pressure-sensitive adhesive on a polyester film, the plate swelled after about 100 sheets, and the plate began to adhere to the printing material, and printing became impossible after 300 sheets had been printed.

Applicant: Aicello Chemical Co., Ltd. Agent Kiyoya Ino Agent Miya 1) Hiroshi Yutaka

Claims (1)

[Claims] (1) Water characterized by having a structure in which a printing surface layer represented by the following composition layer A is formed on a base film, and an adhesive support layer represented by the following composition layer B is laminated thereon. Developable photosensitive film for screen plate making. A composition layer: (a) polyvinyl alcohol or a polyvinyl alcohol derivative, (b) a photopolymerizable monomer having an ethylenically unsaturated bond in the molecule and a photopolymerization initiator, (c) a photocrosslinking agent, (d) A fine powder of polyethylene polymer with a softening point of 100°C or more, a particle size of 1 to 20 μm, and a density of 0.92 or more, or a fine powder of tetrafluoroethylene resin with a particle size of 1 to 20 μm, or a combination of these two types of fine powder. A photosensitive resin composition layer consisting of a mixture. B composition layer: (a) polyvinyl alcohol or polyvinyl alcohol derivative, (b) photopolymerizable monomer having an ethylenically unsaturated bond in the molecule and photopolymerization initiator, (c) photocrosslinking agent, (e) A photosensitive resin composition layer consisting of a hydrophobic polymer emulsion.