JP2000351284A - Stencil for screen printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a printed material of high picture quality by uniform passage of ink through a stencil when printing is carried out in the case of plate- making printing. SOLUTION: The stencil for screen printing has a perforation having an opening area of 1-320 μm2 and an opening ratio of 20-95%, and a porous supporting body comprising a film-shaped material having a thickness of 5-20 μm is provided. In this case, the porous supporting body is preferably laminated to a thermoplastic resin film for perforation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive stencil sheet, and more particularly, to irradiating flash light from a xenon lamp or the like, irradiating pulsed heat energy from a laser oscillation element, or using a fine and large number of heating elements. The present invention relates to a thin sheet material (porous support) in a heat-sensitive stencil sheet made by heating with a thermal head.

[0002]

2. Description of the Related Art Conventionally, a thermoplastic resin film (thermoplastic resin film for perforation) such as a polyester film or a vinylidene chloride film, and a thin paper, a nonwoven fabric, a gauze, etc. mainly composed of natural fibers and / or chemical fibers. A heat-sensitive stencil sheet having a structure in which a porous support is bonded with various adhesives is known (JP-A-59-138497).
JP, JP-A-4-7198, JP-A-51-15
449, JP-A-61-102296, JP-A-52-40809, and JP-A-63-207694.
JP, JP-A-4-239694, JP-A-4-24-2
39693, JP-A-4-221698, JP-A-6-99677).

[0003] However, when a plate is made using such a conventional heat-sensitive stencil sheet and is used for printing, the perforations formed in the base sheet, the gaps between the fibers and the like are not uniform, and a good printed matter is obtained. Have difficulty. In addition, the constituent fibers are present in a bundle of a plurality of fibers, which are bonded to a thermoplastic resin film (thermoplastic resin film for perforation). May be unperforated. Further, even when a porous material is formed using a foam material, the diameter of the holes is not uniform, and in this case, the printed image is inferior in detail.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a heat-sensitive stencil sheet for stencil printing which eliminates the above-mentioned variation in image quality due to printing in plate-making printing. Is to do.

[0005]

The present inventor has studied the heat-sensitive stencil printing paper for high-definition printing (pixel density 600 dpi) in recent years from various angles.
As the porous support of the thermal stencil sheet, the opening area has been found that the aperture ratio in 1μm ² ~320μm ² is valid that with 20% to 95% of a fine porous support. By bonding a thermoplastic resin film (thermoplastic resin film for perforation) to this porous support,
After the perforation, the ink passed through all the holes uniformly, and it was confirmed that the image quality of printing was improved.

That is, according to the present invention, first, a film material having a perforated portion having an opening area of 1 μm ^{2 to} 320 μm ² , an aperture ratio of 20% to 95%, and a thickness of 5 μm to 20 μm. Stencil printing paper comprising a porous support comprising:

Secondly, there is provided the stencil printing stencil according to the first aspect, wherein the film-like material constituting the porous support comprises a thermoplastic resin.

Thirdly, there is provided the stencil printing paper according to the first or second aspect, wherein the porous support is bonded to a thermoplastic resin film for perforation.

Fourthly, there is provided the stencil printing stencil according to the third aspect, wherein the melting point of the film material constituting the porous support is higher than the melting point of the thermoplastic resin material for perforation. You.

Fifth, there is provided the stencil printing paper according to any one of the first to fourth aspects, wherein the opening of the porous support is perforated by using an excimer laser device.

The stencil printing paper of the present invention has an opening area of 1
μm ² ~320μm ² aperture ratio has a perforated portion of 20% to 95% in and since having a porous support having a thickness of a film like material 5Myuemu～20myuemu, uniform ink passage is guaranteed As a result, there is no variation in image quality at the time of printing. (Note that the opening area referred to herein means the area of one perforation.) In particular, it is assumed that the porous support has a laminated structure of the perforated thermoplastic resin film and further has a porous support material. By using a material whose melting point is higher than the melting point of the thermoplastic resin film for perforation, even if heat is applied to the thermoplastic film during plate making (during perforation), the perforated portion of the porous support does not change. .

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in more detail.
You. FIG. 1 shows the porous support of the stencil sheet of the present invention.
It is a schematic cross section. In FIG. 1, 1 is a porous support,
2 indicates a support material, and 3 indicates a hole (opening).
The support generally has a melting point higher than that of the perforated thermoplastic film.
Use expensive materials. To obtain this porous support, a constant
A metal plate with an opening formed with a regular pattern.
Superimposed on the support material film
Irradiate an excimer laser from the metal plate side.
Is performed. At this time, the opening area is 1 μm ^Two~ 320 μm^Two
Area of the metal plate so that the aperture ratio becomes 20% to 95%
To process. As shown in FIG. 2, the shape of the opening is a circle [FIG.
-(A)], ellipse [Fig. 2- (b)], square [Fig.
(C)], triangle [Fig. 2- (d)], or these
A mixture of circles, ellipses, squares, and triangles [Figure 2-
(E)]. Mixed type of [Fig. 2- (e)]
Is useful for preventing moiré. Thickness of film for support material
The appropriate length is 5 μm to 20 μm.

When the opening area is less than 1 μm ² , when the number of perforations is small, the ink supply is insufficient and good printing cannot be performed. Further, if a large number of holes having a diameter of less than 1 μm ^{2 are} simply formed, the strength of the film is reduced, and problems such as insufficient conveyance and printing durability occur in printing. If the perforations are larger than 320 μm ^2, it is impossible to supply an appropriate amount of ink to the portion perforated by the thermal head, resulting in a situation where ink is excessively discharged, and the ink supply function of the porous support cannot be utilized. If the aperture ratio is less than 20%, the ink supply amount is insufficient, and if it is more than 95%, the ink passage amount is too large. In addition, the thickness of the support material film is defined as 5
When the thickness is less than μm, there is a problem in transporting the stencil sheet for the stencil printing machine, and when the thickness is more than 20 μm, it is necessary to perform several times of laser irradiation and perforation when excimer laser is used.

As the film-like material constituting the porous support, a thermoplastic resin is preferable. For example, polyvinyl acetate, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, Examples include vinyl resins such as styrene-acrylonitrile copolymer, polyamides such as polybutylene and nylon, polyphenylene oxide, (meth) acrylate, polycarbonate, cellulose derivatives such as acetylcellulose, acetylbutylcellulose, and acetylpropylcellulose, and polyurethane. Can be These resin materials may be used alone or in combination of two or more.

In order to control the formation, strength, pore size, stiffness and the like of the porous support, it is preferable to add an additive such as a filler to the porous support as needed. Here, the filler is a concept including pigments, powders, and fibrous substances. Among them, needle-like, plate-like or fibrous fillers are particularly preferred. Specific examples include magnesium silicate, sepiolite, potassium titanate, wollastonite, zonotolite, mineral needle fillers such as gypsum fiber, non-oxide needle whiskers, oxide whiskers, and double oxide whiskers. Artificial mineral needle fillers such as mica, glass flakes, talc, etc., and natural or synthetic fibrous fillers such as carbon fiber, polyester fiber, glass fiber, vinylon fiber, nylon fiber, and acrylic fiber. .

The pigment is not only an inorganic pigment but also an organic pigment, organic polymer particles such as polyvinyl acetate, polyvinyl chloride and polymethyl acrylate, and zinc oxide, titanium dioxide, calcium carbonate and silica. Matsumoto Yushi Pharmaceutical's microcapsules and Matsumoto Microsphere can also be used effectively. The addition amount of these additives is preferably 8% to 20% based on the resin. If it is 8% or less, it is difficult to improve the bending rigidity by adding the additive.
Conversely, if it is 20% or more, the adhesiveness between the porous support and the thermoplastic resin film for perforation tends to decrease.

Further, an antistatic agent, an anti-stick agent, a surfactant, a preservative, an antifoaming agent and the like can be used in combination with the porous support of the present invention as long as the effects of the present invention are not impaired. .

FIG. 3 is a schematic sectional view showing a case where the porous support 1 and the thermoplastic resin film 4 for perforation are bonded together. As the thermoplastic resin film for perforation, any thermoplastic resin film known in this field can be used. For example, polyester, nylon, polyethylene, polypropylene, polyvinylidene chloride, polyvinylidene fluoride, or a photopolymer thereof may be used. The thickness of the thermoplastic resin film for perforation is 1 μm
4.0 μm is appropriate. This film has a thickness of 1μ
If the thickness is smaller than m, the work of laminating with the support film will be inconvenient.

FIG. 4 is a sketch of the material of the present invention shown in FIG. 2 observed from the perforation side (the side of the thermoplastic resin film for perforation) when the material was actually perforated with a thermal head.

A stick prevention layer made of a silicone-based or fluorine-based release agent is provided on the surface of the thermoplastic resin film (thermoplastic resin film for perforation) of the heat-sensitive stencil sheet of the present invention, if necessary. . This stick prevention layer is formed before or after lamination with the porous support.

When printing is performed on a stencil printing plate using the base paper of the present invention, high quality printing can be obtained even in a solid portion by uniform ink passage.

[0022]

The stencil printing paper according to claims 1 to 3 has an opening area of 1 μm ^{2 to} 320 μm ² and an opening ratio of 20% to 95%.
With a porous support made of a film material having a thickness of 5 μm to 20 μm, the ink uniformly passes through all the holes when plate making printing is performed using this base paper. Thus, a high-quality printed matter can be obtained.

In the stencil printing paper according to the fourth aspect, the melting point of the film-like material constituting the porous support is higher than the melting point of the thermoplastic resin material for perforation. In this case, even if heat is applied to the perforated thermoplastic resin film during perforation, the perforated portion of the porous support does not change.

In the stencil printing paper according to the fifth aspect, since the porous support is formed by perforating the support film using an excimer laser apparatus, desired perforations are easily formed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one example of a porous support in the present invention.

FIGS. 2A and 2B are plan views showing examples of perforation of a porous support in the present invention, wherein FIG. 2A shows a case of circular perforation, FIG. 2B shows a case of elliptical perforation, FIG. ) Shows the case of triangular perforation, and (e) shows the case of circular, elliptical, square, and triangular mixed perforations.

FIG. 3 is a schematic cross-sectional view showing one example of a stencil sheet of the present invention.

FIG. 4 is a diagram observed from the perforation side when the stencil sheet of the present invention is perforated on a thermoplastic resin film for perforation by a thermal head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Porous support 2 Support material 3 Porous part (opening) of a porous support 4 Thermoplastic resin film for perforation

Claims (5)

[Claims] 1. A numerical aperture opening area in 1μm ² ~320μm ² has a perforation of 20% to 95%, and thickness of 5μm
A stencil printing paper comprising a porous support made of a film material having a thickness of about 20 μm. 2. The method according to claim 1, wherein the film-like material constituting the porous support comprises a thermoplastic resin.
The stencil sheet described in the above. 3. The stencil printing paper according to claim 1, wherein the porous support and the thermoplastic resin film for perforation are bonded together. 4. The stencil sheet according to claim 3, wherein the melting point of the film-like material constituting the porous support is higher than the melting point of the thermoplastic resin material for perforation. 5. The method according to claim 1, wherein the opening of the porous support is perforated by using an excimer laser device.
5. The stencil sheet according to any one of items 1 to 4.