JPS5930540A - Photoengraving method of type by photosensitive resin - Google Patents

Abstract

PURPOSE:To photoengrave a type having high durability by covering a photosensitive resin with a negative film using a block copy of a type, subjecting the same to temporarily exposing and temporarily washing out, further covering the same with a negative film having a bolder type part and subjecting the same to normal exposing and normal washing. CONSTITUTION:A negative film 7 which is reversed in negative and positive is formed from a block copy 1, and the cover film 3 of a plate material 2 is stripped and is brought into tight contact with a photosensitive resin 4. Such resin is temporarily exposed then washed out whereby a temporary plate body 12 is obtd. A negative film 11 indicating a type M' bolder than the type M of the block copy is formed by making the exposing time longer in the stage for forming the negative film and after such film is brought into contact with the surface of the resin 4 formed with the body 12 and is subjected to normal exposure, the film is subjected to normal washing out, whereby a normal plate body 14 is obtd. The resulted body 14 has a stepped part 15 of a specified width on the circumference of the root part. Since the body 14 is securely supported by the stepped part 15, said plate body is strong to the impact with printing and is less vulnerable to chipping, cracking, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a type plate making method using a photosensitive resin such as photosensitive nylon as a plate material.

Plate making using photosensitive resin is excellent in terms of ease and economy, and is often used for newspaper plate making and the like.

Most of these materials are treated as letterpress materials that use type, lines, or dots as the base material, but there are some problems that remain in using them for printing devices such as typewriters, which are explained below. This placed certain limits on the versatility of plate making. That is, since the printing plate is made of resin, its durability is relatively short, and if it is used for a long period of time like the typewriter mentioned above, type defects such as chips and cracks can occur in the protruding parts. It was not suitable.

In view of the above-mentioned points, the present invention aims to improve the durability of printing plates made of photosensitive resin by reinforcing the type portions, that is, the above-mentioned protruding portions.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The figure shows the plate-making process according to the conventional method and the present invention.
1) is typeface (M) created using a typewriter or phototypesetting machine.
), and (2》) is the plate material.
) is a layered structure consisting of an opaque cover film (3), a photosensitive nylon resin layer (4), an adhesive layer (5) and a polyester substrate (6).

First, regarding the conventional plate-making method, it mainly consists of a negative film creation step (a), an exposure step (b), and a washout and drying step (c). Said version (
The negative film (7) created by reversing the yin and yang from 1] is the version! After peeling off the cover film (3) of A (2), it is closely adhered onto the photosensitive resin (4). In the next exposure step (b), the film (7) is irradiated from above with a chemical lamp for several minutes, and the negative film (7) is removed after the irradiation. The resin (4) is washed out with water, alkaline, alcohol, etc., and after this is done thoroughly, it is dried to form the plate (8).
get. That is, in the photosensitive resin (4), only the light-receiving part (9) thereof is cured and becomes insoluble in the exposure step (b),
In the next step (c), the non-light-receiving area (10) is washed away, leaving behind a printing plate (8) that has the same shape as the printing area (type area) of the printing plate.

In contrast, the method of the present invention consists of the following steps (a), (f), (g), and (7) described below.

In the present invention, in addition to the conventional step (A), the negative film production process is carried out by increasing the exposure time and printing a negative film (11
) in the step of obtaining ). First, in the temporary exposure step (e), exposure is performed using the same negative film (7) as in the conventional method, and then in the preliminary washing and drying step (v), a temporary plate (12) is obtained. Rather than completely washing away the non-light-receiving area (10), the surface area is simply washed away in a thin layer, so that the photosensitive resin (4) becomes the temporary plate (12) corresponding to the light-receiving area (9). and the crosspiece (16) connecting the bases of the six temporary plates (12) remain.

After sufficiently drying this, the photosensitive resin (another negative film (11) mentioned above is brought into close contact with the gradient) and the main exposure is carried out. Place the thick type part (M) of the negative film (11) on the body (12).
The temporary plate (12) is exposed again and the resin (4) of the temporary plate is sufficiently washed out (the stepped main plate shown in the figure). (14
) is obtained. This main plate body (14) has a shape similar to that of the conventional plate body (8) described above, with a stepped portion (15) of a constant width formed around the base portion. (
15), so it is resistant to shocks caused by printing.
It has a structure that does not easily chip or crack.

A feature of the printing plate obtained by the present invention is that a stepped portion is formed around the base of the printing plate that can be raised. , a part of the crosspiece (16) may come into contact with the printing paper surface and stain it. In addition, if the sides of the plate are made to be wider than before to strengthen the plate, there is a similar risk, and the corners of the plate will come off, making the print unclear. There is a simple drawback. Therefore, it is preferable that the step (15) in the present invention has an appropriate height and a certain width, but the negative film (11) on the side forming this step is not necessarily caused by overexposure as described above. No problem. For example, the bold type (b) may be obtained by blurring the focus, or may be obtained by creating another block copy. It should be noted that the effectiveness of the present invention is not certain when using minute designs, photographs, etc. as a block copy, and it is most effective when dealing with type, lines, dots, etc. It is also fully applicable to marks and the like, and the term "printed characters" as used in the present invention includes these.

As explained above, according to the present invention, the base of the protruding portion of the printing plate, that is, the plate material, can be stepped, thereby increasing its strength and improving durability. The sharpness of the image will not be lowered to 1.

[Brief explanation of the drawing]

The figure shows the plate-making method for each step.1(a)(b)
G/→ indicates a process according to the conventional method, and (a) ni) (e) (he) ()l ffl indicates a process according to the method of the present invention. (4)...Photosensitive resin (7)@...Negative film (
11)...-Negative film (M)...Print (M)...
・Print

Claims (1)

[Claims] The photosensitive resin was covered with a negative film using the type as a printing plate, and after preliminary exposure, it was washed out temporarily, and then it was covered with a negative film with the type part thicker than the above negative, and after the actual exposure, the actual washing was carried out. A typesetting method using a photosensitive resin.