JPH0952469A - Thermal stencil printing plate base paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perforate a heat melting perforation film efficiently by heat from a thermal head by sticking a heat melting perforating film to a porous support body through a finely porous resin-containing adhesive so as to form a thermal stencil printing plate base paper. SOLUTION: A porous support body and a heat melting perforation film are stuck together through an adhesive layer so as to form a thermal stencil printing plate base paper. To the adhesive layer, a finely porous resin is added. For the finely porous resin, a resin having thermoplastic property, for example, a finely porous polyurethane resin is preferable. A pore-diameter of the finely porous resin is set to 0.1-30μm, a density is set to 0.1-0.8g/cm<3> , and a softening point is set to 50-200 deg.C. By such a structure, the adhesive layer comes to have a low density and heat from a thermal head does not move to the porous support body, so that perforation can be done efficiently.

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 a heat-sensitive stencil sheet produced by a thermal head.

[0002]

2. Description of the Related Art A heat-sensitive stencil sheet is usually prepared by laminating an ink-permeable porous support and a heat-melting perforating film via an adhesive. A plate is created by punching shapes such as letters and figures by heat. Then, printing is performed using this plate.

As this plate making method, a digital plate making method using a thermal head and a method of irradiating infrared rays or xenon flash light are already known. In particular, the digital plate making method using a thermal head has advantages such as low printing cost when printing a large number of sheets and high-speed printing as compared with electrostatic copying (PPC).
And it is rapidly spreading to schools. When performing plate making with a thermal head, a stick prevention layer or the like is provided on the film to prevent the head from heat-sealing to the hot-melt perforable film, and the thermal head is used to heat the perforated film. I am making a plate.

In the conventional heat-sensitive stencil paper which is subjected to a digital plate making method using a thermal head, a synthetic resin having a film-forming property or a synthetic resin which continuously exists is used as a porous support and a hot-melt pierceable film. It is used to glue. This is to increase the adhesive strength of the adhesive.

[0005]

However, since the conventional adhesive used above has a film-forming property or is continuously present, the adhesive is a hot-melt pierceable film. And a high density between the support and the support. For this reason,
There has been a problem that heat applied from the thermal head to the hot-melt pierceable film moves through the adhesive toward the support, and the heat sensitivity of the hot-melt pierceable film at the time of piercing is impaired.

Therefore, the present invention solves the above-mentioned drawbacks, and there is no loss of heat applied to the hot-melt perforable film from the thermal head, and the heat can efficiently perforate the hot-melt perforable film. The main purpose is to provide a heat-sensitive stencil sheet.

[0007]

The above object can be achieved by the present invention described below. That is, the present invention is a heat-sensitive stencil sheet comprising a porous support and a heat-meltable perforated film bonded thereto via an adhesive layer, wherein the adhesive contains a microporous resin. It is a base paper.

[0008]

Next, how to carry out the present invention will be described in detail.

The heat-sensitive stencil sheet of the present invention basically has a constitution in which a porous support and a hot-melt pierceable film are bonded together via an adhesive layer. The greatest feature of the present invention is that the adhesive layer contains a microporous resin.
As the microporous resin, those having thermoplasticity are preferably used. In particular, a microporous polyurethane resin that is thermoplastic is preferable.

The adhesive layer of the present invention comprises an adhesive capable of adhering a porous support and a hot-melt pierceable film, and contains a microporous resin. As a mode of including the microporous resin in the adhesive layer, the conventionally used adhesive may contain a separate microporous resin,
Alternatively, the conventionally used adhesive itself may be a microporous resin. As an adhesive that has been conventionally used, for example, vinyl acetate-based, acrylic-based, vinyl chloride vinyl acetate copolymer-based, polyester-based, polyurethane-based, polyamide-based emulsion type, solvent type, solvent-free type, Examples thereof include hot melt type, ultraviolet ray curable type and electron beam curable type. A particularly preferable microporous resin is a microporous polyurethane resin. Further, other additives such as an antistatic agent and a lubricant may be added to these adhesive layers, if necessary.

The microporous polyurethane resin particularly preferred as the microporous resin is obtained from various polyisocyanates and polyols, and various grades are commercially available and can be used in the present invention. The microporous polyurethane resin can be mixed with various solvents such as toluene and methyl ethyl ketone to obtain an adhesive.

As described above, since the adhesive layer contains the microporous resin, the adhesive layer existing between the hot-melt pierceable film and the porous support is different from the conventional adhesive layer. In contrast, the density is low. Thereby, the heat from the thermal head provided on the hot-melt pierceable film does not move to the porous support and is released, and the heat-melt pierceable film can be efficiently pierced. Therefore, the heat-meltable perforated film can be satisfactorily perforated without impairing the heat sensitivity of the heat-meltable perforated film.

The microporous resin contained in the adhesive layer of the present invention preferably has a pore diameter of 0.1 to 30 μm, preferably 0.1 to 10 μm. If the pore diameter of the microporous resin is less than 0.1 μm, sufficient perforation sensitivity cannot be obtained. On the other hand, when the pore size is larger than 30.0 μm,
Since the size of the pore diameter is close to the size of one dot of the thermal head, the size of the perforated holes is not constant.

The microporous resin is 0.1 to 0.8 g /
A density of cm ³ is preferred. If the microporous resin density is less than 0.1 g / cm ³ , sufficient adhesive strength cannot be obtained. On the other hand, when the density is higher than 0.8 g / cm ³ , sufficient perforation sensitivity cannot be obtained.

Furthermore, the microporous resin has a softening point of 50 to 50.
Preferably it is 200 ° C. When the softening point is less than 50 ° C, heat-resistant storage stability becomes poor, and delamination may occur, whereby the porous support and the hot-melt pierceable film may be separated. On the other hand, if the temperature exceeds 200 ° C, sufficient perforation sensitivity cannot be obtained.

Examples of the hot-melt perforable film used in the present invention include polyvinyl chloride film, vinyl chloride-vinylidene chloride copolymer film, polyester film,
Polyethylene, polyolefin film such as polypropylene, polystyrene film, etc., preferably a thickness,
Any film having a thickness of 0.5 to 20 μm can be used,
There is no particular limitation. A film having a small thickness is advantageous in terms of sensitivity, but is disadvantageous in terms of cost. Therefore, the film may be selected in consideration of the property that the thermal energy of the thermal head used can be used for perforation.

A commonly used hot melt perforable film is a stretched polyester film. Polyethylene terephthalate film is crystalline (crystallinity)
It has high sensitivity and low sensitivity, and has a thickness of 1.5 to 2.5 μm. The film that can be preferably used in the present invention is a high-sensitivity film having a thickness of 0.5 to 6.0 μm, such as a copolyester film having low melting energy, high heat shrinkage, and low crystallinity. As these films, for example, a copolyester film having a melting energy of 3 to 11 cal / g and a difference between the melting end temperature and the melting start temperature of 50 to 100 ° C. (JP-A-62-149496), 140.
Copolymerized polyester film having a heat shrinkage ratio at 15 ° C to 80% and a heat shrinkage stress at 120 ° C of 150 to 500 g / mm ² (JP-A-63-160895), two melting peaks are observed. A film characterized by the above (Japanese Patent Application Laid-Open No. 3-39294), having a heat shrinkage ratio at 100 ° C. of 1
5% or more and 80% or less, the heat shrinkage stress at 100 ℃ is 75
An example is a copolymerized polyester film (Japanese Patent Application Laid-Open No. 62-282983) of about 500 g / mm ² .

The porous support used in the present invention may be any porous support that does not substantially have perforation properties when heated and allows ink to pass through during printing. And natural fibers, synthetic fibers such as polyester, vinylon, nylon and rayon,
These may be used alone or in combination of two or more kinds, wet or dry papermaking, screen printing gauze of polyester, nylon and the like.

Further, in the present invention, in order to prevent the thermal head from being heat-sealed to the hot-melt perforable film, a stick-preventing agent may be coated on the hot-melt perforable film to provide an anti-stick layer. . Examples of the stick inhibitor include water- and oil-repellent agents, surfactants, silicone-based agents, and fluorine-based agents having release performance. Further, other additives such as antistatic agents and lubricants may be added to these, if necessary.

[0020]

The embodiments of the present invention will be specifically described below with reference to Examples and Comparative Examples of the present invention.

[0021]

Example 1 30 parts by weight of a microporous polyurethane resin (Heimlen X-3040: manufactured by Dainichiseika Kogyo Co., Ltd.), 20 parts by weight of toluene, 10 parts by weight of methyl ethyl ketone and 40 parts by weight of water were mixed to obtain an adhesive. . This adhesive has a thickness of 10μ
m polyethylene terephthalate (PET) film was coated with a wire bar at a rate of 0.5 g / m ² . Then, a 40 μm-thick porous thin paper was overlaid on the PET film and bonded by wet lamination to obtain a heat-sensitive stencil sheet. The adhesive layer has a diameter of 3 μm
And the density was 0.5 g / cm ³ .

[0022]

Example 2 Instead of the above microporous polyurethane resin, a microporous polyurethane resin (Heimlen ATX-
10: manufactured by Dainichi Seika Kogyo Co., Ltd., and a heat-sensitive stencil sheet was obtained in the same manner as in Example 1. The adhesive layer of this heat-sensitive stencil sheet has pores with a diameter of 0.5 μm and a density of 0.5 g / cm ^3.
Met.

[0023]

[Comparative Example] 5 parts by weight of polyester having no pores, a density of 1.25 g / cm ³ , and a softening point of 165 ° C, and polyester 5 having no pores, a density of 1.23 g / cm ³ , and a softening point of 145 ° C. By weight, 45 parts by weight of toluene and 45 parts by weight of methyl ethyl ketone were mixed to obtain an adhesive. A heat-sensitive stencil sheet was obtained in the same manner as in Example 1 except that this adhesive was used instead of the adhesive in Example 1.

[0024]

[Evaluation Test] The heat-sensitive stencil sheets obtained in Examples 1 and 2 and Comparative Example were perforated and printed by a preport printing machine (VT-3820). Then, the perforated heat-sensitive stencil sheet and the obtained printed matter were visually evaluated for sensitivity and image clarity in two grades of O and X. Table 1 shows the results.

[0025]

[Table 1]

From the results shown in Table 1, it can be seen that the heat-sensitive stencil sheets obtained in Examples 1 and 2 are superior to the heat-sensitive stencil sheet of Comparative Example in terms of sensitivity and image clarity. From this, it can be seen that the use of the microporous resin as the adhesive improves the sensitivity of the heat-sensitive stencil sheet and the image clarity of the obtained printed matter.

[0027]

As described above, according to the present invention, a heat-sensitive stencil sheet having a constitution in which a porous support and a hot-melt pierceable film are bonded with an adhesive containing a microporous resin The density of the adhesive layer present between the perforable film and the support will be low. Therefore, the heat-meltable perforated film can be efficiently perforated by the heat from the thermal head. Therefore, the heat sensitivity of the heat-meltable perforated film is not impaired.

Claims (4)

[Claims] 1. A heat-sensitive stencil sheet obtained by laminating a heat-meltable perforated film on a porous support through an adhesive layer, wherein the adhesive layer contains a microporous resin. Stencil paper. 2. The pore diameter of the microporous resin is 0.1 to 30 μm.
m, density 0.1 to 0.8 g / cm ³ , softening point 50 to 2
The heat-sensitive stencil sheet according to claim 1, which has a temperature of 00 ° C. 3. The pore diameter of the microporous resin is 0.1 to 10 μm.
The heat-sensitive stencil sheet according to claim 1 or 2, which is m. 4. The heat-sensitive stencil sheet according to claim 1, 2 or 3, wherein the microporous resin is a polyurethane resin.