JPH08324147A - Stencil sheet and engraving method therefor - Google Patents

Abstract

PURPOSE: To provide a stencil sheet capable of being directly and lightly engraved from an electronic original formed by a computer or a word processor without using an expensive engraving unit, easily perforated with water solvent at the time of engraving and having excellent resistance to emulsion ink containing water at the time of printing and a method for engraving the same. CONSTITUTION: (1) The stencil sheet 5 is obtained by laminating a solvent soluble resin film 1 containing polyvinyl acetal resin having 2 to 89mol% of acetalization degree to a porous support 4. (2) The method for engraving the perforated stencil sheet 5 comprises the steps of selectively bringing the solvent into contact with the surface of the film of the sheet 5, dissolving the film 1 of the contact part, and perforating it. (3) The method for engraving the stencil sheet uses the solvent containing organic solvent to be incorporated in water. (4) The method for engraving the stencil sheet uses the organic solvent to be incorporated in water and containing polyhydric alcohol in such at least one hydroxyl group is substituted for 1-4C alkoxy group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil sheet and a method of making the same, and more specifically, a stencil sheet and a method of making the same which can directly and easily make an electronic manuscript edited by a word processor, a computer or the like with a solvent. Regarding

[0002]

2. Description of the Related Art In recent years, with the development of word processors, personal computers, etc., electronic manuscripts can be easily created. A laser printer or an inkjet printer is suitable for reproducing a small amount of a hard copy of this electronic manuscript, but a stencil printing or an offset printing, which has a low unit price per sheet, is an effective means for reproducing a large amount of a hard copy. . However, an apparatus for directly making a plate on an electronic manuscript on a base paper for printing is rarely used except for a plate making process by printing specialists, and since it is expensive, it is difficult to easily make and print a plate in an office or the like. is there. For this reason, the actual situation is that once a hard copy of an electronic manuscript is actually made with a laser printer or the like, and then this hard copy is copied as a manuscript by a copier or a printing specialist is requested to print. However, such work causes problems such as impairing the immediacy of the electronic manuscript and complicating the work. From such a background, it is desired to develop a stencil sheet and a stencil making method capable of directly making a high quality stencil printing plate from an electronic manuscript created by a computer, a word processor or the like without using an expensive plate making device.

[0003]

DISCLOSURE OF THE INVENTION In order to meet the above-mentioned conventional requirements, the present inventors have proposed a method of selectively perforating a stencil sheet obtained by laminating a solvent-soluble film on a porous support using a solvent. (Japanese Patent Laid-Open No. 7-47654)
Japanese Patent Application No. 6-29785, Japanese Patent Application No. 7-1013
No. 4). In this case, since the stencil sheet is used in the office or at home, as a solvent used in the plate making process, those which are safe for the human body, for example, an aqueous solvent is preferable, but such a stencil sheet soluble in an aqueous solvent is However, there is a defect that the resistance to emulsion ink containing water, which is widely used for stencil printing, is insufficient.

An object of the present invention is to eliminate the drawbacks of the above technique, and to directly and easily make a stencil sheet from an electronic manuscript created by a computer, a word processor or the like without using an expensive plate making device. It is another object of the present invention to provide a stencil sheet which is easily perforated with an aqueous solvent and has excellent resistance to an emulsion ink containing water at the time of printing, and a plate-making method thereof.

[0005]

The inventions claimed in this application are as follows. (1) A stencil sheet comprising a porous support and a solvent-soluble resin film containing a polyvinyl acetal resin having an acetalization degree of 2 to 82 mol%. (2) A method for making a stencil sheet, which comprises bringing a solvent into contact with the film surface of the stencil sheet according to (1) to dissolve the solvent-soluble resin film at the contact portion and perforating. (3) A method for making a stencil sheet, wherein the solvent described in (2) is a solvent containing an organic solvent miscible with water. (4) A stencil sheet characterized in that the water-miscible organic solvent according to (2) or (3) contains a polyhydric alcohol in which at least one hydroxyl group is substituted with an alkoxy group having 1 to 4 carbon atoms. Plate making method.

The polyvinyl acetal resin used in the present invention is obtained by condensing polyvinyl alcohol with an aldehyde and has an acetalization degree of 2 to 82 mol%.
It is preferably 5-75 mol%, more preferably 8-70 mol%. As the polyvinyl alcohol used for the condensation, those having a saponification degree of about 75 to 99.8 mol% and a polymerization degree of about 200 to 4,500 are generally used.
As the aldehyde, for example, aliphatic aldehyde such as formaldehyde, acetaldehyde, butyraldehyde and its derivative, aromatic aldehyde such as benzaldehyde, 2-methylbenzaldehyde and its derivative, etc. are used.

If the degree of acetalization of the polyvinyl acetal resin is less than 2 mol%, problems such as swelling due to water contained in the emulsion ink and breaking of the sheet during printing or deformation of the printed image occur. Further, if the degree of acetalization exceeds 82 mol%, the solubility in an aqueous solvent becomes poor. In the present invention, the degree of acetalization of the polyvinyl acetal resin is measured by ¹³ C nuclear magnetic resonance spectroscopy.

The above polyvinyl acetal resin is used alone or in a range not impairing the object of the present invention to form a solvent-soluble resin film by mixing with other resins. The film may contain a dye, a pigment, a filler, a binder, a curing agent and the like. As the resin other than the polyvinyl acetal resin, for example, polyethylene, polypropylene, polyisobutylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinyl acetate, acrylic resin, polyamide, polyimide, polyester,
Polycarbonate, polyurethane, polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose,
Hydroxyethyl cellulose, polyvinylpyrrolidone,
A polymer containing ethylene-vinyl alcohol copolymer, polyethylene oxide, polyvinyl ether, polyacrylic acid, polyacrylamide, carboxylate or sulfonate as a structural unit can be used. The thickness of the solvent-soluble resin film is usually 0.01 to 100 μm, preferably 0.1 to 50 μm. If the thickness is too thin, the strength of the solvent-soluble resin film becomes insufficient, and if it is too thick, it may be difficult to dissolve the solvent-soluble resin film.

As the porous support used in the present invention, natural fibers such as Manila hemp, pulp, Mitsumata, Kozo and Japanese paper, synthetic fibers such as polyester, nylon, vinylon and acetate, metal fibers, glass fibers and the like may be used alone or Examples include thin paper, non-woven fabric, screen gauze and the like that are used by mixing. The basis weight of the porous support is preferably in the range of 1 to ²⁰ g / m ² , and more preferably 10 to 50 μm. The stencil sheet of the present invention can be produced, for example, by the following methods, but the invention is not limited to these methods.

A solvent-soluble resin film containing a polyvinyl acetal resin can be produced by a casting method, a stretching method or the like. Here, a method of producing by coating will be described. First, a solvent-soluble resin is dissolved in a solvent to prepare a resin solution. The solvent at this time may be the same as or different from the solvent used for the plate making of the stencil sheet, but from the viewpoint of the production efficiency of the base paper, it is preferable to use a solvent having good drying property and film forming property. The viscosity and surface tension of the resin solution are appropriately adjusted in consideration of the coating conditions for the non-adhesive support described below. Next, the above-mentioned resin solution is applied onto the non-adhesive support by means of a roll coater, a gravure coater, a wire bar coater, a reverse coater or the like and dried to form a solvent-soluble resin film.

Next, the solvent-soluble resin film formed on the non-adhesive support is attached to the porous support. As a method for laminating, there are adopted (1) a method using an adhesive or a pressure-sensitive adhesive, (2) a method of heat-sealing a solvent-soluble resin film and a porous support, and the like. In the method (1), a solvent-soluble or water-dispersed adhesive is applied to a solvent-soluble resin film or a porous support, and then adhered or heat-cured or light-cured to bond them together. Further, a hot melt type adhesive or pressure sensitive adhesive may be heat fused. As such a pressure-sensitive adhesive or adhesive, it is preferable that the film after curing dissolves in a solvent that dissolves the solvent-soluble resin film, such as epoxy resin, phenol resin, vinyl acetate, ethylene-vinyl acetate copolymer, Acrylic resin, polyester, polyurethane, styrene-butadiene copolymer, polyisobutylene, isoprene, butyl rubber, polyacrylamide, rosin, terpene, styrene and the like can be used. Moreover, you may mix and use a hardening | curing agent, a softening agent, a tackifier, a filler, etc. as needed.

The method (2) can be adopted when the solvent-soluble resin film and / or the porous support contains a heat-meltable component. In this case, the porous support is attached by a heating device such as a heat roller.
Then, the non-adhesive support is peeled from the solvent-soluble resin film to obtain a stencil sheet obtained by laminating the solvent-soluble resin film on the porous support. FIG. 1 is an explanatory view of a stencil sheet manufacturing process showing one embodiment of the present invention, (A)
Shows a state in which the solvent-soluble resin film 1 is formed on the non-adhesive support 2, and (B) shows a state in which the adhesive or pressure-sensitive adhesive layer 3 is formed on the surface of the porous support 4. Also,
(C) shows a state where the non-adhesive support 2 is peeled from the solvent-soluble resin film 1 after the (A) is attached to the (B).

The stencil sheet of the present invention is prepared by making a solvent-soluble resin film containing a polyvinyl acetal resin which composes the sheet, selectively dissolving it in a solvent corresponding to image information, and punching. Considering that stencil printing is used in offices and homes, it is preferable to use an aqueous solvent such as alcohol as the solvent for dissolving the film. From the viewpoint of the solubility of the film, at least one hydroxyl group of the polyhydric alcohol has 1 to 4 carbon atoms,
It is preferable to use a polyhydric alcohol substituted with an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. Examples of such a solvent include triethylene glycol monobutyl ether and ethylene glycol monobutyl ether.

In the present invention, the method of selectively bringing the solvent into contact with the surface of the solvent-soluble resin film is not particularly limited, but, for example, intermittent (dot-like) or continuous (line-like) depending on the character image signal. It is possible to employ an inkjet method in which the solvent is selectively discharged. According to the inkjet method, the solvent can be brought into contact with the film surface in a non-contact state by ejecting the solvent from the solvent ejection nozzle onto the film surface. In this case, the opening diameter of the solvent discharge nozzle is preferably 150 μm or less from the viewpoint of resolution, and more preferably in the range of 30 to 100 μm. Moreover, in order to stably discharge the solvent from the nozzle, the surface tension of the solvent at 20 ° C. is 30 to 600 dy.
It is preferably in the range of ne / cm. Further, the solvent may contain additives such as a surfactant, a moisturizer, and a coloring agent in consideration of the ejection property from the nozzle.

The stencil sheet produced as described above can be used for general stencil printing. For example, the ink is placed on one surface of a stencil sheet that has been plate-making, the printing paper is superposed on the other surface, and the ink is passed through the perforated portion by means such as pressing, depressurizing, and a squeegee to apply the ink to the printing paper. It can be transferred to obtain a printed matter. For the printing ink, in addition to the oil-based ink used in conventional printing, water-based ink, water-in-oil (W / O) type emulsion ink, oil-in-water (O / W) type emulsion ink, etc. are used. Also has excellent printing durability.

[0016]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, parts and% mean parts by weight and% by weight, respectively, unless otherwise specified. Example 1 (1) Production of stencil sheet Polyvinyl acetal resin having a degree of acetalization of 8 mol% was added to a polypropylene film having a thickness of 40 μm which is a non-adhesive support (S-REC KX-1, trade name manufactured by Sekisui Chemical Co., Ltd.).
A solution consisting of 5 parts and 0.5 part of polyacrylic acid was applied by a roll coater and dried to provide a solvent-soluble resin film having a thickness of 1 μm. Next, an acrylic adhesive (solid content 40%) 25 is applied to a 200 mesh polyester fiber cloth.
Part, 60 parts of isopropanol and 15 parts of toluene are applied, and then the pressure-sensitive adhesive layer and the solvent-soluble resin film formed on the polypropylene film are superposed, and a nip pressure of 2 kg / cm ² is applied. The stencil sheet was obtained by laminating with a roller and then peeling off the polypropylene film.

(2) Plate making of stencil sheet Using a discharge device equipped with a nozzle of 8 dots / mm (aperture of 45 μm) and a piezoelectric element, an aqueous solution containing 20% by weight of triethylene glycol monobutyl ether was discharged in a letter form to form a solvent. The soluble resin film was perforated in a letter shape. (3) Stencil printing On the polyester fiber side of the stencil sheet prepared above,
A black high-mesh ink for print Gokko (Ideka Kagaku Co., Ltd.) was placed, and printing paper was overlaid on the other side, and stencil printing was performed using Print Gokko PG-10 (Ideka Kagaku Co., Ltd.). The film was not dissolved by the printing ink, and clear characters could be printed corresponding to the perforations.

Example 2 (1) Production of stencil sheet 5 parts of polyvinyl acetal resin having a degree of acetalization of 70 mol% was added to a polypropylene film having a thickness of 40 μm which is a non-adhesive support (S-REC BL-S, manufactured by Sekisui Chemical Co., Ltd. A solution consisting of (trade name) and 95 parts of ethyl acetate was applied by a roll coater and dried to provide a solvent-soluble resin film having a thickness of 1 μm. Next, 25 parts of acrylic adhesive (solid content 40%) on 200 mesh polyester fiber cloth,
After applying a pressure-sensitive adhesive solution consisting of 60 parts of isopropanol and 15 parts of toluene, the pressure-sensitive adhesive layer and the solvent-soluble resin film formed on the polypropylene film are overlapped and attached with a pressure roller having a nip pressure of 2 kg / m ^2. I matched it.

(2) Stencil sheet making and stencil printing 1 part ethylene glycol monobutyl ether was used as a solvent.
A solvent-soluble resin film was perforated in the same manner as in Example 1 except that an aqueous solution containing 0% by weight was used. When stencil printing was carried out in the same manner as in Example 1,
The film of the stencil sheet was not dissolved by the printing ink, and clear characters corresponding to the perforated portion could be printed.

Example 3 (1) Production of stencil sheet A stencil sheet was produced in the same manner as in the method of Example 1. (2) Stencil sheet making and stencil printing Example 1 except that an aqueous solution containing 30% by weight of triethylene glycol monomethyl ether was used as a solvent.
A solvent-soluble resin film was perforated in a character shape in the same manner as in. When stencil printing was performed in the same manner as in Example 1, clear characters corresponding to the perforated portion could be printed without the film of the stencil sheet being dissolved by the printing ink.

Comparative Example 1 (1) Production of stencil sheet A polypropylene film having a thickness of 40 μm, which is a non-adhesive support, was mixed with 5 parts of polyvinyl alcohol resin and 95 parts of water.
Part of the solution was applied by a roll coater and dried to form a solvent-soluble resin film having a thickness of 1 μm. Then 20
A 0 mesh polyester fiber cloth was coated with a pressure sensitive adhesive solution consisting of 25 parts of an acrylic pressure sensitive adhesive (solid content 40%), 60 parts of isopropanol and 15 parts of toluene, and then formed on the pressure sensitive adhesive layer and the polypropylene film. Overlapping with solvent-soluble resin film, nip pressure 2kg
/ Cm ² of bonded at pressure roller, to obtain a stencil sheet peeling the polypropylene film.

(2) Stencil sheet making and stencil printing A solvent-soluble resin film was perforated in the same manner as in Example 1 except that water was used as the solvent. (3) Stencil printing On the polyester fiber side of the stencil sheet prepared above,
A black high-mesh ink for print gokko, which is a W / O emulsion ink (brand name made by Ideal Science Co., Ltd.), is placed on top of it, and a printing paper is overlaid on the other side to print gokko PG.
When stencil printing was carried out with -10 (trade name of Ideal Science Co., Ltd.), the film of the stencil sheet was dissolved by the water in the ink, and characters could not be printed.

Comparative Example 2 (1) Production of stencil sheet A stencil sheet was produced in the same manner as in Example 1. (2) Stencil sheet stencil making and stencil printing An aqueous solution containing 20% by weight of triethylene glycol was discharged in letter form using a discharge device equipped with a nozzle of 8 dots / mm (caliber 45 μm) and a piezoelectric element. The soluble resin film was not sufficiently dissolved and could not be perforated.

[0024]

According to the stencil sheet and the plate-making method thereof of the present invention, a high-quality printing plate can be obtained from an electronic manuscript created by a computer, a word processor, etc., since it is easily dissolved and perforated by an aqueous solvent during plate-making. A stencil printing plate can be directly and easily prepared to obtain a stencil printing plate. Further, since the stencil printing plate has excellent resistance to emulsion ink containing water during printing, a clear printed image can be obtained by stencil printing.

[Brief description of drawings]

FIG. 1 is an explanatory view of a stencil sheet manufacturing process showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Solvent-soluble resin film, 2 ... Non-adhesive support, 3
... Adhesive or tacky agent, 4 ... Porous support, 5 ... Stencil sheet.

Claims (4)

[Claims] 1. A stencil sheet comprising a porous support and a solvent-soluble resin film containing a polyvinyl acetal resin having an acetalization degree of 2 to 82 mol%. 2. A method for making a stencil sheet, which is characterized in that a solvent is brought into contact with the film surface of the stencil sheet according to claim 1, the solvent-soluble resin film at the contact portion is dissolved and perforated. 3. A plate making method for a stencil sheet, wherein the solvent according to claim 2 is a solvent containing an organic solvent miscible with water. 4. The stencil sheet according to claim 2, wherein the water-miscible organic solvent contains a polyhydric alcohol having at least one hydroxyl group substituted with an alkoxy group having 1 to 4 carbon atoms. Plate making method.