JP2021084305A - Treatment liquid for screen printing plate, and treatment method for screen printing plate - Google Patents

Abstract

To provide a treatment liquid for a screen printing plate obtained by thermal plate making which can reduce generation of pin holes of a screen printing plate, and can remove molten residues of a thermoplastic resin film of the screen printing plate.SOLUTION: A treatment liquid for a screen printing plate obtained by thermal plate making contains a solvent containing at least one selected from the group consisting of an ester-based solvent having a solubility parameter of 8.9-13.5 (cal/cm3)1/2, a ketone-based solvent having a solubility parameter of 8.9-13.5 (cal/cm3)1/2 and an amide-based solvent having a solubility parameter of 8.9-13.5 (cal/cm3)1/2, and a water-insoluble resin.SELECTED DRAWING: None

Description

An embodiment of the present invention relates to a processing liquid for a screen printing plate obtained by thermal plate making, and a processing method for the screen printing plate.

The thermoplastic resin film of the thermal stencil master, which is formed by laminating a thermoplastic resin film to a porous support, is selectively heated by a thermal head and melt-perforated to form a perforated portion corresponding to an image. A plate making method for producing a plate for stencil printing such as screen printing is called thermal plate making. As the thermal stencil master, for example, a thermal screen master using a screen gauze as a porous support can be used.

As the thermoplastic resin film used for the thermal screen master, a very thin film having a thickness of about 1 to 5 μm is usually used in order to enable perforation with a thermal head. Due to the thinness of the film, minute holes (pinholes) may be generated in the film when printing a large number of sheets, and the minute dots may be printed in an unintended place of the printed matter.
In Patent Document 1, a liquid containing a resin is applied onto the film of a screen printing plate after plate making, a resin solution is left only on an unmade plate portion, and then the film is dried to form a resin film to reinforce the film. A method has been proposed.

Further, when a heat-sensitive screen master is made with a heat-sensitive digital plate-making machine, the melt due to the heat of the thermoplastic resin film may stick to the screen gauze of the perforated portion as a residue. The melt residue stuck to the perforated portion may cause blurring of edges and image defects.
Patent Document 2 describes that the molten residue is remelted by a method of heating the portion to be drilled a plurality of times. Patent Document 3 describes that after plate making, the melt residue is removed by wiping with anon, MEK, or a mixed solvent of anon and MEK.

Japanese Unexamined Patent Publication No. 7-89043 Japanese Unexamined Patent Publication No. 10-291290 Japanese Unexamined Patent Publication No. 10-86546

An embodiment of the present invention is a processing liquid for a screen printing plate obtained by heat-sensitive plate making, which can reduce the occurrence of pinholes in the screen printing plate and is a thermoplastic resin film for the screen printing plate. Screen printing that can remove the melt residue of the processing liquid that can remove the melt residue, suppress the generation of pinholes in the screen printing plate, and remove the melt residue of the thermoplastic resin film of the screen printing plate. One purpose is to provide a method of processing plates.

One embodiment of the present invention is an ester solvent, which is a treatment liquid for a screen printing plate obtained by heat-sensitive plate making and has a solubility parameter of 8.9 to 13.5 (cal / cm ³ ) ^1/2. solubility parameter of 8.9~13.5 (cal ^/ cm ^{3) 1/2} in a ketone solvent, and a solubility parameter of 8.9~13.5 (cal ^/ cm ³⁾ amide solvents is ^1/2 The present invention relates to a treatment liquid containing a solvent containing at least one selected from the group consisting of and a water-insoluble resin.
Another embodiment of the present invention relates to a method for processing a screen printing plate, which comprises processing the screen printing plate obtained by thermal plate making with the processing liquid of the above embodiment.

According to the embodiment of the present invention, it is a processing liquid for a screen printing plate obtained by heat-sensitive plate making, that can reduce the occurrence of pinholes in the screen printing plate, and is a thermoplastic resin film for the screen printing plate. Screen printing that can remove the melt residue of the processing liquid that can remove the melt residue, suppress the generation of pinholes in the screen printing plate, and remove the melt residue of the thermoplastic resin film of the screen printing plate. A plate processing method can be provided.

This is an example of a photograph of the surface of the perforated portion of the screen printing plate taken at a magnification of 100 times.

Hereinafter, embodiments of the present invention will be described in detail, but it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes may be made.

The treatment liquid of the embodiment is a treatment liquid for a screen printing plate obtained by heat-sensitive plate making, and is an ester solvent having a solubility ^{parameter of 8.9 to 13.5 (cal / cm 3} ) ^1/2. from parameter 8.9~13.5 (cal ^/ cm ^{3) 1/2} in a ketone solvent, and a solubility parameter of 8.9~13.5 (cal ^/ cm ^{3) 1/2} in which an amide solvent A treatment liquid containing a solvent containing at least one selected from the above group and a water-insoluble resin.

The treatment liquid of the present embodiment can reduce the occurrence of pinholes in the screen printing plate and remove the melt residue of the thermoplastic resin film of the screen printing plate.

The thermoplastic resin film before being heated by the thermal plate making tends to have orientation and relatively high crystallinity. On the other hand, the melt residue of the thermoplastic resin film is obtained by cooling and solidifying the thermoplastic resin film melted by heating the heat-sensitive plate making, and it is considered that a considerable part of the melt residue is in an amorphous state. The solubility parameter contained in the treatment liquid is 8.9 to 13.5 (cal / cm ³ ) ^1/2 , and the solubility parameter is 8.9 to 13.5 (cal / cm ³ ) ^1/2 . At least one selected from the group consisting of a ketone solvent and an amide solvent having a solubility parameter of 8.9 to 13.5 (cal / cm ³ ) ^1/2 is a non-perforated portion that has not been heated and melted. It is considered that the thermoplastic resin film is difficult to dissolve, while the melt residue of the thermoplastic resin film can be dissolved. Further, the dissolved melt residue reinforces the screen printing plate together with the water-insoluble resin contained in the treatment liquid, so that a high reinforcing effect can be obtained and pinholes in the unperforated region of the screen printing plate are reduced. It is thought that it can be done. By reducing the pinholes of the screen printing plate, it is possible to reduce the ink moving from the pinholes of the screen printing plate to an unintended place of the printed matter and forming dot-like stains.

By using this treatment liquid, reinforcement of the screen printing plate and removal of the melt residue of the thermoplastic resin film of the screen printing plate can be performed by an operation using one treatment liquid, and the process from plate making to printing can be performed. The number and time can be reduced. Further, by using a treatment liquid containing a solvent and a water-insoluble resin, it is easy to suppress clogging of the perforated portion of the water-insoluble resin. Further, as described above, by using this treatment liquid to reinforce the screen printing plate and remove the melt residue, the reinforcing effect of the screen printing plate can be improved.

The treatment liquid is an ester solvent having a solubility parameter (hereinafter, sometimes referred to as “SP value”) of 8.9 to 13.5 (cal / cm ³ ) ^1/2 , and an SP value of 8.9 to 13. .5 least (cal ^/ cm ^{3) 1/2} in a ketone solvent, and the SP value is selected from the group consisting of an amide solvent is from 8.9 to 13.5 (cal ^/ cm ^{3) 1/2} One type (hereinafter, may be referred to as "solvent A") can be included.

As a method for calculating the solubility parameter, a plurality of methods such as Hildebrand, Fedors, and Hansen have been proposed, but in the present invention, the three-dimensional Hansen solubility parameter is used. The Hansen solubility parameter δ is represented by ^{δ 2} = δ _D ² + δ _P ² + δ _H ² from the three components of the dispersion force term (δ _D ), the polar term (δ _P ), and the hydrogen bond term (δ _H).
More specifically, POLYMER HANDBOOK. FOURTH EDITION. (Editors. J. BRANDRUP, E.H. IMMERGUT, and EA GRULKE.) And the like.

Examples of the ester solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 include propylene carbonate (SP value 13.3 (cal / cm ³ ) ^1/2 ) and γ-. Butyrolactone (SP value 12.8 (cal / cm ³ ) ^1/2 ), 1,2-butylene carbonate (SP value 12.1 (cal / cm ³ ) ^1/2 ), dimethyl succinate ((SP value 9.). 7 (cal / cm ³ ) ^1/2 ), dimethyl glutarate (SP value 9.6 (cal / cm ³ ) ^1/2 ), dimethyl adipate (SP value 9.6 (cal / cm3) 1/2) , Methyl propionate (SP value 9.0 (cal / cm ³ ) ^1/2 ), ethyl acetate (SP value 8.9 (cal / cm ^{3 ) 1/2} ) and the like.

Examples of the ester solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 include cyclic ester solvents such as propylene carbonate, γ-butyrolactone, and 1,2-butylene carbonate, and Kohaku. Diester solvents such as dimethyl acid, dimethyl glutarate, and dimethyl adipate, or combinations thereof are preferable.

The SP value of the ester solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 is 8.9 (from the viewpoint of removing the melt residue of the thermoplastic resin film of the screen printing plate). cal / cm ³ ) ^1/2 or more is preferable, 9.2 (cal / cm ³ ) ^1/2 or more is more preferable, 10.0 (cal / cm ³ ) ^1/2 or more is further preferable, and 11.0 (cal / cm 3) cal / cm ³ ) ^1/2 or more is more preferable. The SP value of the ester solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 is 13.5 (from the viewpoint of removing the melt residue of the thermoplastic resin film of the screen printing plate). preferably cal ^/ cm ³⁾ is ^1/2 or less, more preferably 13.0 (cal ^/ cm ^{3) 1/2} or less.

SP value SP value of the ester solvent is 8.9~13.5 (cal ^/ cm ^{3) 1/2,} for example, 9.2~13.5 (cal ^/ cm ³⁾ It is ^1/2 Is more preferable, 10.0 to 13.5 (cal / cm ³ ) ^1/2 is even more preferable, and 11.0 to 13.0 (cal / cm ³ ) ^1/2 is even more preferable.

The treatment liquid may contain only one type of ester solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 , or a combination of two or more types.

Examples of the ketone solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 include acetone (SP value 9.7 (cal / cm ³ ) ^1/2 ) and cyclohexanone (SP). Examples thereof include a value of 9.5 (cal / cm ³ ) ^1/2 ) and a methyl ethyl ketone (SP value of 9.3 (cal / cm ³ ) ^1/2).

The SP value of the ketone solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 is 8.9 (from the viewpoint of removing the melt residue of the thermoplastic resin film of the screen printing plate). cal / cm ³ ) ^1/2 or more is preferable, and 9.2 (cal / cm ³ ) ^1/2 or more is more preferable. The SP value of the ketone solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 is 13.5 (from the viewpoint of removing the melt residue of the thermoplastic resin film of the screen printing plate). preferably cal ^/ cm ³⁾ is ^1/2 or less, more preferably 13.0 (cal ^/ cm ^{3) 1/2} or less.

SP value SP value of ketone solvent is 8.9~13.5 (cal ^/ cm ^{3) 1/2,} for example, 9.2~13.5 (cal ^/ cm ³⁾ It is ^1/2 Is more preferable, and 9.2 to 13.0 (cal / cm ³ ) ^1/2 is even more preferable.

The treatment liquid may contain only one type of ketone solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 , or a combination of two or more types.

As the amide-based solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 , dimethylformamide (SP value 12.1 (cal / cm ³ ) ^1/2 ), N-methyl- 2-pyrrolidone (SP value 11.2 (cal / cm ³ ) ^1/2 ) and the like can be mentioned.

As the amide solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 , for example, a cyclic amide solvent (lactam solvent) such as N-methyl-2-pyrrolidone is preferable.

The SP value of the amide-based solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 is 8.9 (from the viewpoint of removing the melt residue of the thermoplastic resin film of the screen printing plate). cal / cm ³ ) ^1/2 or more is preferable, 9.2 (cal / cm ³ ) ^1/2 or more is more preferable, 10.0 (cal / cm ³ ) ^1/2 or more is further preferable, and 11.0 (cal / cm 3) cal / cm ³ ) ^1/2 or more is more preferable. The SP value of the amide-based solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 is 13.5 (from the viewpoint of removing the melt residue of the thermoplastic resin film of the screen printing plate). preferably cal ^/ cm ³⁾ is ^1/2 or less, more preferably 13.0 (cal ^/ cm ^{3) 1/2} or less.

SP value SP value of the amide-based solvent is 8.9~13.5 (cal ^/ cm ^{3) 1/2,} for example, 9.2~13.5 (cal ^/ cm ³⁾ It is ^1/2 Is more preferable, 10.0 to 13.5 (cal / cm ³ ) ^1/2 is even more preferable, and 11.0 to 13.0 (cal / cm ³ ) ^1/2 is even more preferable.

The treatment liquid may contain only one type of amide solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2 , or a combination of two or more types.

Solvent A is one or more ester-based solvents having an SP value of 8.9 to 13.5 (cal / cm ^{3 ) 1/2} , and an SP value of 8.9 to 13.5 (cal / cm 3). ³ ) ^{One or two or more ketone solvents that are 1/2} , and one or two or more amide solvents that have an SP value of 8.9 to 13.5 (cal / cm ³ ) ^1/2. Alternatively, a combination thereof may be included.

With solvent A, the cyclic ester solvent SP value is 8.9~13.5 (cal ^/ cm ^{3) 1/2,} the SP value is 8.9~13.5 (cal ^/ cm ^{3) 1/2} there diester solvents, SP value 8.9~13.5 (cal ^/ cm ^{3) 1/2} in a cyclic amide solvent, SP value 8.9~13.5 (cal ^/ cm ^{3) 1/2} It is preferable to contain a ketone solvent or a combination thereof.
The boiling point of the solvent A is not particularly limited, but the boiling point is preferably more than 100 ° C, more preferably 120 ° C or higher.

The amount of the solvent A in the treatment liquid is not particularly limited.
From the viewpoint of improving the effect of removing the melt residue of the thermoplastic resin film of the screen printing plate, the solvent A is preferably 10% by mass or more, more preferably 20% by mass or more, based on the total amount of the treatment liquid. It is more preferably 30% by mass or more, and even more preferably 40% by mass or more. On the other hand, from the viewpoint of improving the reinforcing effect of the screen printing plate by the resin and further effectively reducing the occurrence of pinholes, the solvent A is preferably 90% by mass or less with respect to the total amount of the treatment liquid. It is more preferably 80% by mass or less, further preferably 70% by mass or less, and further preferably 60% by mass or less. The solvent A is, for example, preferably 10 to 90% by mass, more preferably 20 to 80% by mass, further preferably 30 to 70% by mass, and 40 to 40% by mass, based on the total amount of the treatment liquid. It is more preferably 60% by mass.

From the viewpoint of improving the effect of removing the melt residue of the thermoplastic resin film of the screen printing plate, the solvent A is preferably 10% by mass or more, preferably 20% by mass or more, based on the total amount of the solvent contained in the treatment liquid. It is more preferably 30% by mass or more, and further preferably 40% by mass or more. On the other hand, from the viewpoint of improving the reinforcing effect of the screen printing plate by the resin and further effectively reducing the occurrence of pinholes, the solvent A is 90% by mass or less with respect to the total amount of the solvent contained in the treatment liquid. It is more preferable, it is more preferably 80% by mass or less, further preferably 70% by mass or less, and further preferably 60% by mass or less. The solvent A is preferably, for example, 10 to 90% by mass, more preferably 20 to 80% by mass, and further preferably 30 to 70% by mass with respect to the total amount of the solvent contained in the treatment liquid. It is preferably 40 to 60% by mass, more preferably 40 to 60% by mass.

From the viewpoint of ease of operation using the treatment liquid, the treatment liquid preferably contains a solvent having a boiling point of 100 ° C. or lower. When the treatment liquid A contains a solvent having a boiling point of 100 ° C. or lower, the solvent is easily dried after the treatment liquid is applied. In particular, for example, when a solvent having a boiling point higher than 100 ° C. is used as the solvent A, it is preferable to further contain a solvent having a boiling point of 100 ° C. or lower.

The treatment liquid may contain, for example, a solvent having a boiling point of 100 ° C. or lower in the solvent A and / or in addition to the solvent A.
The solvent having a boiling point of 100 ° C. or lower is not particularly limited, and examples thereof include alcohol-based solvents. The treatment liquid preferably further contains an alcohol solvent having a boiling point of 100 ° C. or lower. Examples of the alcohol-based solvent having a boiling point of 100 ° C. or lower include alcohol-based solvents having 4 or less carbon atoms such as methanol, ethanol, isopropyl alcohol, and propanol.
Examples of the solvent A having a boiling point of 100 ° C. or lower include ethyl acetate and methyl ethyl ketone.

The treatment liquid may contain only one type of solvent having a boiling point of 100 ° C. or lower, or a combination of two or more types.

When the treatment liquid contains a solvent having a boiling point of 100 ° C. or lower, the amount of the solvent having a boiling point of 100 ° C. or lower is not particularly limited. The solvent having a boiling point of 100 ° C. or lower is preferably 20% by mass or more, more preferably 30% by mass or more, based on the total amount of the treatment liquid. On the other hand, the solvent having a boiling point of 100 ° C. or lower is preferably 60% by mass or less, more preferably 50% by mass or less, based on the total amount of the treatment liquid. The solvent having a boiling point of 100 ° C. or lower is, for example, preferably 20% by mass to 60% by mass, more preferably 30 to 50% by mass, based on the total amount of the treatment liquid.
When the treatment liquid contains an alcohol solvent having a boiling point of 100 ° C. or lower, the alcohol solvent having a boiling point of 100 ° C. or lower is preferably 20% by mass or more, preferably 30% by mass or more, based on the total amount of the treatment liquid. More preferred. On the other hand, the alcohol solvent having a boiling point of 100 ° C. or lower is preferably 60% by mass or less, more preferably 50% by mass or less, based on the total amount of the treatment liquid. The alcohol solvent having a boiling point of 100 ° C. or lower is preferably, for example, 20% by mass to 60% by mass, more preferably 30 to 50% by mass, based on the total amount of the treatment liquid.

When the treatment liquid contains a solvent having a boiling point of 100 ° C. or lower, the solvent having a boiling point of 100 ° C. or lower is preferably 20% by mass or more, more preferably 30% by mass or more, based on the total amount of the solvent contained in the treatment liquid. preferable. On the other hand, the solvent having a boiling point of 100 ° C. or lower is preferably 60% by mass or less, more preferably 50% by mass or less, based on the total amount of the treatment liquid. The solvent having a boiling point of 100 ° C. or lower is, for example, preferably 20% by mass to 60% by mass, more preferably 30 to 50% by mass, based on the total amount of the treatment liquid.
When the treatment liquid contains an alcohol solvent having a boiling point of 100 ° C. or lower, the alcohol solvent having a boiling point of 100 ° C. or lower is preferably 20% by mass or more, preferably 30% by mass or more, based on the total amount of the solvent contained in the treatment liquid. More preferably. On the other hand, the alcohol solvent having a boiling point of 100 ° C. or lower is preferably 60% by mass or less, more preferably 50% by mass or less, based on the total amount of the treatment liquid. The alcohol solvent having a boiling point of 100 ° C. or lower is preferably, for example, 20% by mass to 60% by mass, more preferably 30 to 50% by mass, based on the total amount of the treatment liquid.

The treatment liquid can contain a water-insoluble resin. The water-insoluble resin preferably has a solubility of less than 0.5 g in 100 g of water at 23 ° C.

Examples of the water-insoluble resin include vinyl-based resin, polyester-based resin, polyurethane-based resin, epoxy-based resin, polyamide-based resin, polyimide-based resin, silicon resin, phenol-based resin, melamine-based resin, urea-based resin, and aniline-based resin. Examples thereof include resins, ionomer resins and polycarbonate resins. Examples of the vinyl-based resin include vinyl acetate-based resins and the like.

As the water-insoluble resin, a polyamide-based resin is particularly preferable. As the polyamide resin, for example, nylon-6, nylon-66, nylon4-6, copolymerized nylon and the like can be used.

From the viewpoint of the solubility of the treatment liquid in the solvent, the polyamide-based resin is preferably an alkoxymethylated polyamide-based resin obtained by alkoxymethylating the polyamide-based resin. Examples of the alkoxymethyl group include a methoxymethyl group and an ethoxyethyl group. Examples of the alkoxymethylated polyamide resin include alkoxymethylated nylon (for example, methoxymethylated nylon) and the like. By alkoxymethylating the polyamide resin, the solubility in an alcohol solvent can be enhanced.

The treatment liquid may contain only one type of water-insoluble resin or a combination of two or more types.

The amount of the water-insoluble resin in the treatment liquid is not particularly limited.
From the viewpoint of reinforcing the screen printing plate, the water-insoluble resin is preferably 1% by mass or more, more preferably 2% by mass or more, and 5% by mass or more, based on the total amount of the treatment liquid. Is even more preferable. On the other hand, from the viewpoint of effectively suppressing clogging of the perforated portion of the screen printing plate, the water-insoluble resin is preferably 50% by mass or less, preferably 30% by mass or less, based on the total amount of the treatment liquid. Is more preferable, and 20% by mass or less is further preferable. The water-insoluble resin is, for example, preferably 1 to 50% by mass, more preferably 2 to 30% by mass, and further preferably 5 to 20% by mass, based on the total amount of the treatment liquid.

The treatment liquid may further contain additives such as a surfactant and an antistatic agent, if necessary.

The method for producing the treatment liquid is not particularly limited. For example, each material can be produced at once or in divided portions and mixed.

The treatment liquid can be preferably used for a screen printing plate obtained by thermal plate making.
The screen printing plate obtained by heat-sensitive plate making is not particularly limited, and may be, for example, one obtained by making a plate by heat-sensitive plate making of a heat-sensitive screen master.

The thermal screen master preferably comprises a screen gauze and a thermoplastic resin film.
The heat-sensitive screen master is preferably one in which a screen gauze and a thermoplastic resin film are bonded together using an adhesive. The heat-sensitive screen master preferably includes, for example, a screen gauze, an adhesive layer formed by using an adhesive, and a thermoplastic resin film in this order.

The screen gauze may be made of fibers such as polyester, nylon, rayon, stainless steel, silk, and cotton, as long as it is not substantially perforated by heating the thermal head and allows ink to pass through in printing. Rayon can be used.

The thickness of the screen gauze is usually 40 to 270 μm, preferably 50 to 150 μm.
The number of meshes of the screen gauze (the number of fibers per inch) is usually 40 to 500, preferably 50 to 350 meshes. The number of meshes in the vertical direction and the number of meshes in the horizontal direction may be the same or different as long as they are within the range of the number of meshes.

As the thermoplastic resin film, for example, a polyethylene resin film, a polypropylene resin film, a polyester resin film, a polyamide resin film, a polyvinyl chloride resin film, a polyvinylidene chloride resin film, or the like can be used. Of these, a polyester resin film can be preferably used. Examples of the polyester resin include polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, ethylene terephthalate / ethylene isophthalate copolymer, butylene terephthalate / ethylene terephthalate copolymer, butylene terephthalate / hexamethylene terephthalate copolymer. Examples thereof include coalescing, hexamethylene terephthalate / 1,4-cyclohexanedimethylene terephthalate copolymer, ethylene terephthalate / ethylene-2,6-naphthalate copolymer and the like. The thermoplastic resin film may contain various additives such as pigments, viscosity modifiers, dispersants, dyes, lubricants, cross-linking agents, and plasticizers, if necessary.

The thickness of the thermoplastic resin film may be as long as it can be used for heat-sensitive digital screen plate making, but is usually 0.5 to 10 μm, preferably 1 to 5 μm.

The thermoplastic resin film preferably has shrinkage properties suitable for being easily melt-perforated by heat-sensitive digital screen plate making, and may be uniaxially or biaxially stretched as appropriate.

The heat-sensitive screen master can be manufactured, for example, by a method including bonding a screen gauze and a thermoplastic resin film with an adhesive.

The adhesive is not particularly limited as long as it can be bonded together so as to satisfy the printing resistance required at the time of printing. For example, an aqueous type, a solvent type, a solvent-free type, a hot melt type, an infrared ray, etc. Examples include photocurable types such as visible light, ultraviolet rays, and electron beams.

Specific examples of the solvent-type adhesive include vinyl acetate-based, polyester-based, and (meth) acrylic-based resins dissolved in the following organic solvents. Specific examples of organic solvents include aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, ketones, esters, ethers, aldehydes, carboxylic acids, amines, low molecular weight heterocyclic compounds, and oxides. Systems and the like include, for example, hexane, heptane, octane, benzene, toluene, xylene, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, butyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, glycerin, acetone, methyl ethyl ketone. , Ethyl acetate, propyl acetate, ethyl ether, tetrahydrofuran, 1,4-dioxane, formic acid, acetic acid, propionic acid, formaldehyde, acetaldehyde, methylamine, ethylenediamine, dimethylformamide, pyridine, ethylene oxide and the like. Specific examples of the photocurable type adhesive include those mainly composed of monomers, oligomers and photopolymerization initiators, and more specifically, polyester-based (meth) acrylates, urethane-based (meth) acrylates, and the like. Examples thereof include epoxy-based (meth) acrylate and polyol-based (meth) acrylate-based photocurable adhesives. These adhesives may contain additives such as antistatic agents, lubricants, tackifiers, fillers and leveling agents, if necessary.

The method of adhering the screen gauze and the thermoplastic resin film with an adhesive is not particularly limited. For example, an adhesive may be applied using a roll coater or the like, and the screen gauze and the thermoplastic resin film may be bonded together.
The method of applying the adhesive is not particularly limited. The adhesive may be applied to the screen gauze using, for example, a roll coater, or may be applied to the screen gauze by immersing the screen gauze in an adhesive diluted with a solvent, for example.

The amount of the adhesive applied is usually in the range of ^{0.05 to 10.0 g / m 2.} From the viewpoint of adhesive strength, the applied amount is ^{preferably 0.05 g / m 2} or more. From the viewpoint of ink permeability and good perforation, the applied amount is ^{preferably 10.0 g / m 2} or less.

The method for heat-sensitive plate making of the heat-sensitive screen master is not particularly limited. The thermal screen master can be used as a screen printing plate by making a plate with a thermal plate making device using a thermal head or the like.

The screen printing plate processing method of the embodiment is a screen printing plate processing method including processing the screen printing plate obtained by thermal plate making with the above-mentioned processing liquid.
The treatment liquid and the screen printing plate are as described above.
According to this screen printing plate processing method, the occurrence of pinholes in the screen printing plate can be suppressed, and the melt residue of the thermoplastic resin film of the screen printing plate can be removed.

The method of processing the screen printing plate with the processing liquid is not particularly limited.

The treatment liquid is preferably applied to the surface of the screen printing plate on the screen side.

The method of applying the treatment liquid is not particularly limited, but it is preferable that the treatment liquid is dropped on the surface of the screen printing plate using, for example, a dropper or a dispenser, and spread on the portion to which the treatment liquid is to be applied with a cotton cloth or the like. ..

The total amount of the treatment liquid to be applied ^{is preferably 10 g / m 2} or more, and more preferably 20 g / m ² or more. The amount of the treatment liquid applied is preferably ^{100 g / m 2} or less as the total amount of the treatment liquid. Application amount of the treatment liquid, for example, preferably ^{10~100g / m 2, 20~100g / m} 2 is more preferable.

From the viewpoint of removing the solvent in the treatment liquid, it is preferable to apply the treatment liquid to the screen printing plate and then dry the treatment liquid on the screen printing plate. The drying method is not particularly limited, and drying with hot air, natural drying, or the like can be appropriately selected.

From the viewpoint of removing the solvent having a relatively high boiling point in the treatment liquid, after applying the treatment liquid to the screen printing plate, if necessary, use ion-exchanged water or the like on the surface to which the treatment liquid of the screen printing plate is applied. It is preferable to wash it. This cleaning is preferably performed after the treatment liquid of the screen printing plate described above has been dried. The cleaning method is not particularly limited, and for example, a method such as wiping the surface to which the treatment liquid of the screen printing plate is applied with a cloth or the like impregnated with ion-exchanged water can be appropriately selected.

The processing method of the screen printing plate may further include other steps or operations.

The screen printing plate processed in this way can be used for stencil printing. As the ink used for printing, for example, an ink that can be used for stencil printing such as screen printing can be used. Such ink may be any of oil-based ink, solvent ink, water-based ink, water-in-oil (W / O) type emulsion ink, water-in-water oil (O / W) type emulsion ink, and plastisol ink.

Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" is "mass%". The blending amount of each material in the table is also indicated by "mass%".

<Manufacturing of treatment liquid>
Tables 1 and 2 show the composition of the treatment liquids of each Example and Comparative Example.
For Examples 1 to 5 and Comparative Examples 1 and 2, the water-insoluble resin shown in Tables 1 and 2 and methanol were mixed to prepare a 20% by mass methanol solution of the water-insoluble resin. A 20% by mass methanol solution of the obtained water-insoluble resin and the remaining solvent were mixed to prepare a treatment liquid of Examples 1 to 5 and Comparative Examples 1 and 2.
For Comparative Example 4, the solvent (cyclohexanone) shown in Table 2 was used as the treatment liquid of Comparative Example 4.

Details of the materials listed in Tables 1 and 2 are shown below.
Polyamide-based resin: "Fine Resin FR-101" manufactured by Namariichi Co., Ltd. (methoxymethylated polyamide-based resin)
Polyvinyl acetate resin: "Bond KE60" manufactured by Konishi Co., Ltd. (containing 50% by mass of solid content and 50% by mass of methanol)
Methanol: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. γ-butyrolactone: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. N-methyl-2-pyrrolidone: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Cyclohexanone: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. : Wako Pure Chemical Industries, Ltd. Fujifilm propyl acetate: Fujifilm Wako Pure Chemical Industries, Ltd.

The "bond KE60" contains 50% by mass of a polyvinyl acetate-based resin and 50% by mass of methanol, but in Tables 1 and 2, the amount of the "polyvinyl acetate-based resin" is the resin contained in the "bond KE60". The amount is (50% by mass) and does not include the amount of methanol contained in "Bond KE60".
Further, in Tables 1 and 2, the amount of "methanol" in Example 5 and Comparative Example 1 in which "Bond KE60" was used is the total amount of methanol including the amount of methanol contained in "Bond KE60".

<Manufacturing of screen printing plate>
A heat-sensitive screen master (“QS120P-56-50” manufactured by Riso Kagaku Corporation) is framed on a plate frame with a tension of 12 N / cm, and is solid with a heat-sensitive screen plate making machine (“GOCCOPRO QS2536” manufactured by Riso Kagaku Corporation). The pattern was heat-sensitive, and a screen-printed plate with a solid pattern was obtained.

<Evaluation>
1. 1. Pore opening ratio (melt residue)
For Examples 1 to 5 and Comparative Examples 1, 2 and 4, the treatment solutions of the Examples and Comparative Examples were added dropwise to the surface of the screen printing plate obtained above on the screen side of the screen printing plate at an imparting amount of 50 g / m ^2. Then, the dropped treatment liquid was spread on the surface of the screen printing plate using a cotton cloth, and then the applied treatment liquid was dried by applying hot air. Then, using a cloth soaked with ion-exchanged water, the surface to which the treatment liquid was applied was wiped off, and this was used as a screen printing plate for evaluation of the aperture ratio.
For Comparative Example 3, the screen printing plate produced above was used as it was for evaluating the aperture ratio without being treated with the treatment liquid.

For each of the treated screen-printed plates of Examples 1 to 5 and Comparative Examples 1, 2 and 4, and the untreated screen-printed plates of Comparative Example 3, the surface of the perforated portion of the screen-printed plate was formed. Photographed with a system microscope BX51 (manufactured by Olympus Corporation) at a magnification of 100 times, and the area S1 of the perforated portion in a predetermined area in this photograph was determined by using the image analysis software "ImagePro Plus" (manufactured by Media Cybernetics). It was.
For the purpose of explaining the area S1 of the perforated portion, an example of a photograph of the perforated portion is shown in FIG. In FIG. 1, 1 is a screen gauze fiber arranged in a grid pattern, and 2 is a melt residue of a thermoplastic resin. The perforated portion is a region of the perforated portion excluding the region of the fiber 1 of the screen gauze and the region of the melt residue 2 of the thermoplastic resin, and is the black portion in FIG. In the image analysis software "ImagePro Plus", the perforated portion, the region of the melt residue of the thermoplastic resin, and the region of the fiber of the screen gauze are binarized according to a predetermined threshold value to determine the area of the perforated portion S1. Was calculated automatically.
Then, the opening rate (%) of the perforated portion (plate making portion) of the screen printing plate is defined as the ratio of the area S1 to the area S2 of the region excluding the region of the fiber 1 of the screen gauze in the predetermined area of the perforated portion as follows. Calculated by the formula.
Opening ratio (%) = (S1 / S2) x 100

The calculated aperture ratio (%) is shown in the table.
The higher the aperture ratio (%), the smaller the melt residue of the thermoplastic resin film of the screen printing plate.

2. Number of Pinholes Occurred The processed screen printing plates of Examples 1 to 5 and Comparative Examples 1, 2 and 4 and Comparative Example 3 obtained in the same manner as those used in the evaluation of the aperture ratio. The number of pinholes generated was evaluated using an untreated screen printing plate.

Each of the processed screen printing plates of Examples 1 to 5 and Comparative Examples 1, 2 and 4 and the untreated screen printing plates of Comparative Example 3 were placed in an aluminum frame having dimensions of 550 mm × 600 mm with a tension of 11 N / N. Framed with cm. Next, this plate frame was set in an automatic screen printing machine (“LS-34GX” manufactured by Neurongue Precision Industry Co., Ltd.), and a cotton cloth was set as a printing medium on the printing table. Plastisol ink (“PLUE 8000” (black) manufactured by Union Ink) is put on the plate, and continuous printing is performed under printing conditions of a squeegee angle of 70 °, a squeegee pressure of 0.30 MPa, and a squeeging speed of 227.5 mm / sec. It was.
The number of black spots (pinholes) of the ink generated in the unmade (non-perforated) portion of the printed matter obtained at the 500th continuous printing was counted, and this was taken as the number of pinholes. The predetermined area to be counted was 210 mm × 297 mm. The number of pinholes counted was evaluated according to the following evaluation criteria. The results are shown in the table.

Evaluation Criteria A: Number of medium pinholes generated in a predetermined area (210 mm x 297 mm) 10 or less B: Number of medium pinholes generated in a predetermined area (210 mm x 297 mm) 11 to 30 C: Number of medium pinholes generated in a predetermined area (210 mm x 297 mm) Over 30

As shown in the table, in Examples 1 to 5, excellent results were shown in both the evaluation of the number of pinholes generated and the evaluation of the aperture ratio.
Further, in Examples 1 to 4 in which the polyamide resin was used, particularly excellent results were shown in the evaluation of the number of pinholes generated.

On the other hand, the SP value is 8.9 to 13.5 (cal / cm ³ ) ^1/2 for the ester solvent, and the SP value is 8.9 to 13.5 (cal / cm ³ ) ^1/2 . Comparative Examples 1 and 2 in which a treatment solution containing neither a certain ketone solvent nor an amide solvent having an SP value of 8.9 to 13.5 (cal / cm ³ ) ^{1/2 was used are all.} , The opening rate was low. In addition, the screen printing plate of Comparative Example 3 which was not treated with the treatment liquid and Comparative Example 4 in which the treatment liquid did not contain the water-insoluble resin had a large number of pinholes.

1 Screen gauze fiber 2 Melt residue of thermoplastic resin

Claims (5)

A processing liquid for screen printing plates obtained by thermal plate making.
Solubility parameter of 8.9~13.5 (cal ^/ cm ^{3) 1/2} in which an ester solvent, a solubility parameter of 8.9~13.5 (cal ^/ cm ^{3) 1/2} in a ketone solvent, And a solvent containing at least one selected from the group consisting of amide-based solvents having a solubility parameter of 8.9 to 13.5 (cal / cm ³ ) ^1/2.
A treatment liquid containing a water-insoluble resin. The treatment liquid according to claim 1, wherein the water-insoluble resin contains a polyamide-based resin. The treatment liquid according to claim 2, wherein the polyamide-based resin contains an alkoxymethylated polyamide-based resin. The solvent is the solubility parameter is 8.9~13.5 (cal ^/ cm ³⁾ cyclic ester solvent is ^1/2, the solubility parameter is in 8.9~13.5 (cal ^/ cm ^{3) 1/2} there diester solvents, solubility parameter 8.9~13.5 (cal ^/ cm ^{3) 1/2} in a ketone solvent, and a solubility parameter of 8.9~13.5 (cal ^/ cm ^{3) 1/2} The treatment liquid according to any one of claims 1 to 3, which contains at least one selected from the group consisting of the cyclic amide solvent. A method for processing a screen printing plate, which comprises processing the screen printing plate obtained by thermal plate making with the processing liquid according to any one of claims 1 to 4.

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