JPH0635214B2 - Method of making heat-sensitive perforating master plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a heat-sensitive perforating original plate.

[Conventional technology]

Transcript printing is widely used as a simple printing method, and various plate-making methods have been proposed and some of them have been put into practical use. Among them, typical methods generally used except for handwriting are the discharge plate making method and the heat sensitive plate making method.

In the electric discharge plate making method, first, a document and a plate material are wound on the same drum and the document image is scanned by rotating the drum,
This is converted into an electric signal by using a photoelectric element like a facsimile. After that, the discharge needles adjacent to the plate material are selectively sparked according to the electric signal, and the energy is used to perforate the plate material in the thickness direction. Disadvantages of this method are that the discharge needle is a consumable item, and that vinyl chloride, paper powder, and odor are generated from the plate material during discharge.

On the other hand, in the heat-sensitive plate making method, the original and the stretched thermoplastic resin film are brought into close contact with each other, and the infrared component is absorbed in the original image by instantaneous exposure, and the surface of the resin film facing the image is contracted by the absorbed heat to punch. It is a thing. However, this system has color selectivity because it uses the absorbed heat and hardly reproduces colors other than black. Therefore, in the case of a color image, it is necessary to once convert it into a black image by an electronic copying machine, and also at that time, there is a risk that the toner image copied by the copying machine is thermally melted and adheres to the plate material.
Further, among the black images, the black image due to the dye has a low heat generation temperature, that is, the perforation is insufficient for a document written with a felt-tip pen or a ballpoint pen.

In order to eliminate such a defect, a plate making method using a thermal recording head having a plurality of heating elements as a heat applying means has been conventionally proposed. For example, Japanese Patent Laid-Open No. 54-331
In Japanese Patent Publication No. 17, a dot-shaped perforation image is formed on a sheet made of only a stretched thermoplastic synthetic resin film by using a printing device having dot-shaped heating elements, and ink is passed through the perforated image portion of the sheet. A method of forming a recorded image at least has been proposed. Also, JP-A-56-3719
In Japanese Patent Laid-Open No. No. 1-83200, a thermal transfer ink layer of carbon paper for hectography is placed on the lower surface of a master image forming base material so as to be in contact with the upper surface of the master image forming base material, and heat is selectively emitted from a thermal recording head. A technique is disclosed in which a master image is transferred from a heat-sensitive transfer ink layer to the lower surface of a master image forming base material by applying.

[Problems to be solved by the invention]

However, each of these methods has drawbacks,
It has not been put to practical use. That is, in the method that does not use the base layer, since the film thickness is thin and the strength is not sufficient, sufficient printing durability cannot be obtained, and the handleability is poor. On the other hand, in the method using hectcarbon paper, since the transfer layer is transferred to the master image forming base material, there is an influence of the thickness of the master image forming base material, and sufficient resolution cannot be obtained. In addition, the master imaging substrate needs to be housed and the device requires extra space. In addition, this method uses the transferred image as an ink layer to perform hect printing, so that 10
Only 0 sheets can be printed.

Therefore, the present inventors, as a novel plate making method by removing the drawbacks of such conventional methods, the thermal recording head is in close contact with the film surface of the perforated master made of the biaxially stretched film provided on the porous base. , Applying heat, forming a perforation image according to the heat applied image on a biaxially stretched film, has proposed a method of creating a printing original plate, the present invention has a perforation property in such a novel plate making method. The purpose is to improve.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention is a method in which a porous base material having an opening ratio of 40% or more and 60% or less and a biaxially stretched thermoplastic resin film are bonded together, and a plurality of thermoplastic resin film surfaces are provided. While contacting the thermal recording head having the heating element, the pressure roller is pressed from the side of the porous base material, and the heating element is electrically heated to a temperature at which the thermoplastic resin film is punched without adhering to the thermal recording head. Provided is a method for producing a heat-sensitive perforating original plate, which comprises perforating a thermoplastic resin film. As the porous base material, in addition to the porous material, a mesh sheet of synthetic resin fibers can be considered. Here, the opening ratio of the porous base material is the sum of the opening areas of the pores with respect to the area of the porous base material sheet, expressed as a percentage.

〔Example〕

The present invention will be described in detail below with reference to the drawings. FIG. 1 shows the basic structure of a heat-sensitive perforating master plate, that is, a perforation master before the perforation step in the method of the present invention. The perforated master 1 has a biaxially stretched film 3 attached to one surface of a porous base material 2. As the porous base material 2, Manila hemp,
As the main raw material, natural fibers such as kozo, mitsumata, synthetic fibers such as tetron, vinylon and acrylic, and semi-synthetic fibers such as rayon can be used. As another base material, a material obtained by weaving fibers having a thickness of about 20 to 70 μm such as nylon, polyester, polypropylene, and tetron can be used. The biaxially stretched film 3 is preferably a polyester film having a thickness of 1 to 5 μm. The biaxially stretched film 3 is adhered to the porous base material 2 with an adhesive. As the adhesive, an adhesive made of a saturated polyester resin, an acrylic resin, a polyvinyl resin, a polystyrene resin, or the like can be used. The adhesive is used by dissolving it in an appropriate amount of solvent in an amount of 0.5 to 2.0 g / m ² in terms of solid content after drying. The porous base material having an opening ratio of 40% or more is used.

Next, a plate making method using such a perforating master will be described. Figure 2 shows the basic principle. The perforating master 1 is passed between the thermal recording head 5 and the pressure roller 6 so that the film surface is in close contact with the heating element. The pressure roller 6 presses the perforating master 1 against the thermal recording head 5 and rotates in the direction of the arrow to move the perforating master 1 in a predetermined direction (sub-scanning direction).
The thermal recording head 5 is a recording element in which a large number of heating elements are arranged in a direction (main scanning direction) orthogonal to the sub-scanning direction, and is driven by a drive signal supplied from a drive circuit 7 of the thermal recording head. That is, an image signal created by reading an original of a RIS (raster input scanner) or an output signal of a word processor is used as a thermal recording head drive circuit 7.
Drive signal is generated, and accordingly, the heating element 4 is selectively energized according to image information to generate heat. When the heating element 4 generates heat, the corresponding portion of the biaxially stretched film 3 on the surface of the perforating master 1 is heated. As a result, the biaxially stretched film is thermally shrunk, and the perforated plate is produced.

The biaxially stretched film of the perforating master used when performing plate making by the above-described method is preferably a polyester film having a thickness of 5 μm or less. The voltage and pulse width applied by the thermal head affect the life of the head and are therefore naturally limited. In general, it is considered that if the energy applied to the head is increased, the temperature of the head rises and the piercing property is improved, but if the applied energy is excessively increased, a problem occurs. One of them is that the biaxially stretched film adheres to the thermal head. To reduce this adhesion,
As described above, the use of a thin biaxially stretched film is effective, but there is a limit to that. Further, if the applied energy is increased, the adhesion becomes severe and the base may be broken when a thin paper is used as the base. In the perforating master, the perforating property is improved only by setting the aperture ratio to 40% or more, so that it is not necessary to increase the energy applied to the head and the base is less likely to be damaged.

Next, the experimental results using the examples of the present invention will be described. First, in the first embodiment, as the base material, the aperture ratio is about 3
Using 0% and about 45% of each thin paper, a biaxially stretched polyethylene terephthalate film of about 3 μm was stuck thereon with an adhesive to obtain a sample. For these samples,
Applied voltage of 25V using a thermal recording head of 12 dots / mm,
Plate making was performed under the printing conditions of an application time of 2 msec. The test was performed so that the heating element of the thermal recording head hits the film surface side. In the case of the base having an opening ratio of 45%, printable perforation was performed, and a clear image was obtained by a copying printer. On the other hand, in the case of the base having an aperture ratio of 30%, the degree of perforation was less than half that in the case of 45%, and even when printed, a very unclear image was obtained.

Next, in the second embodiment, the aperture ratio as a base is about 50%.
Aperture ratio of about 6 made by weaving thin paper and synthetic resin fiber
A 0% mesh sheet was used, and a biaxially stretched polyethylene terephthalate film having a thickness of about 2 μ was bonded thereto with an adhesive to obtain a sample. These samples were tested under the same conditions as in Example 1. In each case, sufficient perforation was performed, and a clear printed image with high density was obtained. Especially when using a mesh sheet of synthetic resin fiber as the base, the applied voltage is 25 V and the application time is 1 ms.
Even when the plate was made under the printing conditions of ec, it was perforated sufficiently and the printed image was clear.

〔The invention's effect〕

According to the present invention, by using a porous base material having an aperture ratio of 40% or more and 60% or less as a base material of a heat-sensitive perforating original plate, and a technique of perforating using a thermal recording head, in combination. The perforability of the heat-sensitive perforating original plate can be improved, and good image quality can be obtained when printing is performed using the heat-sensitive perforating original plate. According to the present invention, since it is not necessary to increase the energy applied to the thermal recording head, the thermoplastic resin film does not adhere to the thermal recording head even when the thermal recording head is brought into contact with the surface of the thermoplastic resin film. Therefore, the porous base material is not damaged.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the basic constitution of a heat-sensitive perforating original plate before the perforating step in the method of the present invention, and FIG. 2 is a schematic showing the basic principle of the perforating step in the heat-sensitive perforating original plate producing method of the present invention. FIG. 1 ... Hole master, 2 ... Porous base material, 3 ... Biaxially stretched film, 4 ... Heating element, 5 ... Thermal recording head,
6 ... pressure roller, 7 ... drive circuit.

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-53-49519 (JP, A) JP-A-57-182495 (JP, A) JP-B-51-15449 (JP, B2)

Claims (2)

[Claims] 1. A thermal recording head having a plurality of heating elements on the surface of a thermoplastic resin film, which is obtained by bonding a porous base material having an opening ratio of 40% or more and 60% or less and a biaxially stretched thermoplastic resin film. And press the pressure roller from the side of the porous base material, and the thermoplastic resin film perforates the thermoplastic resin film by electrically heating the heating element to a temperature at which the thermoplastic resin film does not adhere to the thermal recording head and is perforated. A method for producing a heat-sensitive perforating original plate consisting of the following. 2. The method for producing a heat-sensitive perforating original plate according to claim 1, wherein the porous base material is a mesh sheet of synthetic resin.