JPS6250308B2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a method for producing a printing original plate.

(Prior Art) Conventionally, as a method for manufacturing letterpress printing plates, for example, an ultraviolet curable resin coated on a substrate is irradiated with ultraviolet rays through an image film to form a cured area and a cured area depending on the density of the image. There is a method in which the cured portion is washed away with a chemical and the remaining cured portion is used to form a convex portion expressing an image.

There is also a method of forming a so-called perforated plate in which a perforated part and a non-perforated part are formed on a substrate in which a hot-melt resin is laminated to a porous support by the heat of light absorption depending on the density of the image on the original plate.

Furthermore, as described in Japanese Utility Model Application Publication No. 54-29702, a method is also known in which a document is printed with ink containing a foaming agent, and this is heated and foamed to form protrusions for stamps. .

(Problems to be Solved by the Invention) According to the above method for manufacturing a printing relief plate, troublesome process operations such as a baking process and a treatment process using chemicals are required, resulting in a problem in workability.

In addition, according to the above-mentioned method for forming a stencil, the substrate is made of a composite material and a hot-melt resin is used, so the process is complicated and labor-intensive. There is a problem with the image reproducibility of the stencil when it is molded.

Furthermore, according to the method described in the above-mentioned Japanese Utility Model Publication No. 54-29702, the height of the protrusions produced by the foaming agent is extremely low, and the parts other than these protrusions are not particularly ink-repellent. When a stamp is made using a stamp, the problem is that the stamp ink adheres to parts other than the protrusions, making the stamp unclear and sometimes turning the stamp entirely black.

Therefore, the present invention was created in view of these points, and uses a simple method to form the printed surface to be ink-receptive, and to form the portion other than the printed surface to be ink-repellent. However, it is an object of the present invention to provide a method for manufacturing a printing original plate that can finish printing neatly and clearly.

[Structure of the invention]

(Means for Solving the Problems) In the method for producing a printing original plate of the present invention, an ink-repellent film containing a foaming agent is formed on a film-like substrate, and the ink-repellent film of the substrate is exposed to the heat of the document plate. The image was transferred onto the ink-repellent film by overlapping an absorbent image and irradiating the substrate with a light beam rich in infrared rays to heat and foam the foaming agent in the part of the ink-repellent film that overlapped the image. A foamed convex portion having an ink-receptive printing surface is formed by swelling.

(Function) In the method for producing a printing original plate of the present invention, a heat-absorbing image of a document plate is superimposed on an ink-repellent film formed on a film-like substrate, and a light beam rich in infrared rays is irradiated onto the film. The foaming agent in the portion of the ink-repellent coating overlapping the image is heated and foamed, and a foamed convex portion having an ink-receptive printing surface is formed on the ink-repellent coating. As a result, the image on the manuscript board is easily transferred and reproduced on the film-like substrate, and the printing original plate has foamed convex portions having an ink-receptive printing surface and portions other than the foamed convex portions that are ink-repellent. is obtained.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1 is a substrate, and this substrate 1 has, for example, a thickness of
The substrate 1 is made of a transparent film such as a polycarbonate film of about 0.15 mm, and an ink-repellent film 2 is formed on one side of the substrate 1 by applying a silicone rubber solvent containing a foaming agent. This ink-repellent film 2 is formed by coating or printing with an ink having the following composition.

10 parts of foaming agent Micropearl F30 (product name) 90 parts of silicone rubber KE45RTV (product name) , this original plate 3 is fixed on the base 5.
The manuscript board 3 is made of, for example, a white sheet of paper or other white material 6, and a heat-absorbing image 4 made of black letters, black paintings, halftone photographs, etc. is printed on the top surface of the manuscript board 3. The expression is formed by etc.

Next, a transparent acrylic plate 7 is superimposed and fixed on the substrate 1, and a light beam from a lighting device 8 such as a lamp rich in infrared rays, a xenon lamp, or a flash is applied to the original plate 3 from above the transparent acrylic plate 7. Irradiation is performed directly or via a reflector plate 9. As a result, the light rays pass through the ink-repellent film 2 through the transparent acrylic plate 7 and the substrate 1, reach the document plate 3, and absorb heat from heat-absorbing images 4 such as black characters on the document plate 3. The image 4 is absorbed and the part of the ink repellent film 2 generates heat, and the foaming agent in the part of the ink repellent film 2 that is in contact with the image 4 is heated and foamed, forming a foam on the ink repellent film 2 as shown in FIG. , a foamed convex portion 10 having an ink-receptive printing surface 11 which is a transfer reproduction of the image 4 on the original plate 3 is formed by swelling. That is, along with the foaming of the foamed convex portions 10, a printing surface 11 consisting of fine irregularities in which ink is retained is formed on the surface of the foamed convex portions 10 by expansion of the foaming agent in the corresponding portions, thereby forming the foamed convexes. The printing surface 11 of the copy 10 has ink receptivity in which ink is retained. The convex portion 10 bulged out from the ink repellent coating 2 of the substrate 1 by about 0.02 to 0.05 mm.

Next, by removing the transparent acrylic plate 7 from above the substrate 1 and removing this substrate 1 from above the document plate 3, the foamed convex portion 10 having the ink-receptive printing surface 11 and the portion other than the foamed convex portion 10 are removed. A printing original plate A having ink repellency is obtained.

In use, a commercially available offset printing ink is applied to the original printing plate A via an ink roll, and it can be used for desired printing such as an offset printing method. In this case, since the printing surface 11 of the foamed convex portion 10 has an uneven, ink-receptive rough surface, the printing ink is reserved on this printing surface 11, but the ink is not deposited on the portion other than the foamed convex portion 10. Due to the ink repellency of the repellent film 2, the printing ink is repelled and the printing ink is not applied to the ink.
The image 4 on the original plate 3 is clearly printed and reproduced on paper or the like by the printing ink reserved on the ink-receptive printing surface 11 of the original plate 3.

The ink forming the ink-repellent film 2 may have the following composition.

Foaming agent Micropearl F30 30 parts Silicone rubber KE455RTV 70 parts or Foaming agent Micropearl F30 10 parts Silicone rubber KE445RTV 90 parts [Effects of the Invention] According to the present invention, an ink-repellent film is formed on a substrate, and this ink By placing a heat-absorbing image on a manuscript plate in contact with the repellent film and irradiating it with light rays rich in infrared rays, the foaming agent in the part of the ink-repellent film that is in contact with the image is heated and foamed, causing ink repulsion. A foamed convex portion having an ink-receptive printing surface that reproduces an image transferred onto a transparent film can be easily and accurately bulge-molded.Moreover, since the printed surface of this foamed convexity is ink-receptive, printing is possible. On the other hand, since the surface of the substrate other than the foamed protrusions is covered with an ink-repellent film, it is difficult to apply printing ink to the printing surface of the foamed protrusions. Due to its ink repellency, the printing ink will not be applied to areas other than the foamed convex areas, and therefore printing can be finished neatly and clearly, and processes such as development and fixing can be completed easily. In addition, it does not require processes such as water treatment and can be easily made in a completely dry state.
Workability can be greatly improved, and offset printing that does not require dampening water can be easily performed during printing, making it possible to obtain an innovative printing original plate with high productivity at a low cost.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a cross-sectional view showing a plate-making state, and FIG. 2 is a cross-sectional view of the same printing master plate. 1... Substrate, 2... Ink repellent film, 3...
Original board, 4... Image, 10... Foaming convex portion, 11...
...Print surface.

Claims (1)

[Claims] 1. Forming an ink-repellent film containing a foaming agent on a film-like substrate, superimposing a heat-absorbing image on a document plate on the ink-repellent film of the substrate, and
Foaming having an ink-receptive printing surface where the image is transferred onto the ink-repellent film by irradiating the substrate with a light beam rich in infrared rays to heat and foam the foaming agent in the part of the ink-repellent film that overlaps the image. A method for producing a printing original plate, characterized by forming convex portions by swelling. 2. The method for producing a printing original plate according to claim 1, wherein the printing surface of the ink-receptive foamed convex portion is formed into a rough surface consisting of fine irregularities.