JPS6052431B2 - Manufacturing method of resin gravure plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a resin gravure plate that can effectively eliminate the effects of pinholes in printed originals or foreign matter attached during printing to obtain high-quality image areas. It is related to the manufacturing method.

The method of obtaining a gravure plate by printing a positive gravure original onto a photocurable photosensitive resin layer is well known. This manufacturing method eliminates the need for complicated plating processes, etc. compared to metallic gravure plates, and therefore can greatly improve the efficiency of the conventional gravure rigid plate process. By the way, when an original is printed on a photosensitive layer in the hardening process of a resin gravure plate, image quality is affected by pinholes contained in the original or foreign substances such as dirt and dust that adhere to the original or the photosensitive layer.

Since these pinholes, foreign objects, etc. cannot be completely avoided, they are printed as part of the image, and unless some processing is performed during the process, they will form part of the image area. And the printed matter becomes a defective product. Conventionally, printing plate areas affected by pinholes, foreign matter, etc. are filled with a resin of the same type as the photosensitive layer and polished to correct them so that they do not become image areas.

However, there are quite a lot of pinholes, foreign objects, etc.
In addition, since the location of the occurrence is not fixed, the above-mentioned correction work requires an enormous amount of time and effort.

Therefore, this method is not very practical. The present invention uses a method called varnishing to eliminate the above-mentioned effects.
I tried the method shown in the figure.

In the figure, 10 is a polyamide-based photosensitive resin layer formed on a cylindrical substrate or a plate-shaped substrate (not shown);
2 is a positive original for gravure, 14 is light, and 16 is varnish.

Then, the original image is printed on the resin layer 10 (1), the unexposed areas 20 corresponding to the pinholes 18 of the original are covered with varnish 16 (), then developed (), and then the second swatch 16 is removed. As a result, as shown in the figure, a step a of several microns was created in areas other than the cell 22, and this appeared as background stains on the printed matter.

This is probably because the upper surface of the photosensitive layer 10 beyond the portion covered with the varnish 16 is also eroded by the developer.

It is thought that such a problem will not occur if the varnish 16 is applied to the very edge of the border with the drawing area, but such processing is almost impossible in practice. The present invention aims to significantly advance this step and provide a method that does not create a step and is almost completely free from the effects of pinholes and the like.

Hereinafter, a preferred embodiment of the present invention will be described based on FIG.

First, on the surface of the polyamide photosensitive resin layer 10,
Another photocurable photosensitive resin layer 24 that is not eroded by the developer of the polyamide photosensitive resin layer is adhered and formed (1
).

This layer 24 is made of, for example, a rubber-based resist (more specifically, 0MR manufactured by Tokyo Ohka Co., Ltd., KTER manufactured by Fuji Yakuhin Co., Ltd.), a polyvinyl cinnamate photoresist (more specifically, TPRlOSR.sKOda manufactured by Tokyo Ohka Co., Ltd.),
It can be formed by applying a liquid such as KPR (manufactured by K.K.) by appropriate means such as spraying, dipping, whealing, vertical coating, etc.

The thickness of layer 24 is preferably a few microns. Since the layer 10 and the layer 24 usually have different photosensitive characteristics, it is considered that the layer 24 should be formed as thin as possible to avoid problems in the subsequent steps (). Then, the layer 2
A positive gravure original 12 is placed on top of the image 4, and the image is printed ().

Examples of burning light sources include ultra-high pressure mercury lamps, high-pressure mercury lamps,
A chemical lamp or the like may be used. When the above image is formed as a latent image on the polyamide photosensitive resin layer 10 and other resin layers 24 by printing, only the layer 24 is developed with a developer (). This developing solution is selected to be one that does not corrode the polyamide photosensitive resin, for example, one containing xylene as a main component, and is brought into contact with the layer 24 by appropriate means such as spraying or dipping. Once layer 24 is developed, a protective film formation step () is then performed. The protective film 16 is formed by varnishing, for example, by a process called varnishing. The varnish is a polyamide photosensitive resin developer (
An alcohol-resistant material that is not corroded in step V (used in step V), such as Tokyo Kasei asphalt, is selected. Here, the protective film 16 covers the pinholes 18 contained in the original as described above.
Alternatively, it should be applied to defective areas caused by foreign matter such as dust that gets into the optical path during printing.

These pinholes and the like act to block light as if there were an image area even though there is a non-image area on the document 12 (). Therefore, in the baking process (), both layers 10 and 24
A latent image such as a pinhole is formed on the layer 10, and when the latent image portion of the layer 24 is removed in the development process, the unexposed portion 20, which is the latent image such as a pinhole, of the layer 10 is exposed. Become. In the protective film forming step, the unexposed area 20 of the layer 10 corresponding to the non-image area and the removed area 26 of the other layer 24 corresponding to the unexposed area are covered, and the unexposed area corresponding to the image area is covered. This is provided to prevent the exposed area from being eroded during the development process V.

After a protective film such as varnish is formed (), the layer 10 is developed and a gravure cell 22 corresponding to the image area is formed ().

A developer is selected that does not attack the upper layer 24 and the protective film 16 but only attacks the lower layer 10; for example, a mixed solution of ethanol and water is used. The developer is preferably sprayed by a spray method. After development, rinsing with ethanol solution is performed as necessary. At this time, since the smooth surface of the layer 10 is covered with the layer 24, the upper surface will not be eroded and the step a will not occur as shown in FIG.

Thereafter, the upper layer 24 and the protective film 16 are removed using a removal solution ().

The removal liquid is insensitive only to the lower layer 10, and is, for example, toluene, trichlene, O-dichlorobenzene, ethyl cellosolve acetate, or the like. Protective film 16 with removal solution,
The upper layer 24 swells or dissolves and is removed from the lower surface.
After this, the surface of the layer 10 is dried, and the corresponding unexposed areas 20 such as pinholes are irradiated with light 14 by post-exposure ().
The plate is completely cured and, if necessary, baked to form a gravure plate. Note that the unexposed area 20 may be slightly depressed because the exposure timing is different from that of the surrounding exposed area, but the depth thereof is within 1 micron and does not cause any trouble to printing. Now, in the present invention, as described above, another photocurable photosensitive resin layer 24 is adhered and formed on the surface of the polyamide photosensitive resin layer 10, a latent image is formed on both layers, and then an upper layer is formed. The gravure plate is prepared by developing only the lower layer 10 after developing the protective film 24 and then developing the lower layer 10.

Therefore, according to the present invention, even if there are pinholes, dust, etc., there is no need for the extremely elaborate and troublesome work of modifying the areas corresponding to the pinholes on the completed plate later, as in the past, and it is possible to simply protect the plate. It is possible to do this by simply applying the film roughly to the area corresponding to the pinhole, and in addition, this process removes the layer of soil that will ultimately become unnecessary in the process before the plate surface is exposed to the outside. The more you do this, the more accurately and neatly you will be able to finish the printing plate. Finally, examples of the present invention are listed.

Example 1 Plate photosensitive polyamide resin (manufactured by Tokyo Ohka Kogyo, TOPL)
A commercially available rubber-based photoresist (1-83 manufactured by Tokyo Ohka Co., Ltd.) is spray-coated to a thickness of 1.5 μm on the photoresist (ON version) and dried.

Next, a printing frame (light source;
2. A positive gravure original with an ultra-high pressure mercury lamp 50W/A: vacuum contact). Intermittent exposure.

After exposure, a rubber photoresist (0MR-83) was sprayed (solvent: xylene) for 3 minutes, and rinsed (solvent: butyl acetate) using the same spray for 1 minute. Next, photosensitive polyamide resin (TOPLON)
Before development, pinholes in the rubber photoresist (0MR-&3) were covered with varnish (asphalt varnish manufactured by Tokyo Kasei, an alcohol-resistant varnish).

After varnishing, spraying of photosensitive polyamide resin (TOPlON) (ethanol 80% water 20%; 30°C;
3.6k9/C7ll) for 1 minute, and spray rinse (ethanol) for 1 second. Finally, the varnish and rubber-based photoresist are removed using toluene, torculene, 0-dichlorobenzene, or the like.

After peeling, drying, post-exposure, and baking, the result was 1 (
B) Line: A plate with a halftone dot density of 50 μm and a cell depth of 50 μm was obtained.

As a result of gravure printing with the plate thus obtained, a clear image without pinholes could be obtained.

Moreover, the image quality was completely free of color loss compared to printed matter made with conventional metal printing plates. Example 2 A photosensitive polyamide resin is endlessly coated on the surface of a gravure cylinder, and a commercially available rubber photoresist (0MR-83 manufactured by Tokyo Ohka Co., Ltd.) is spray-coated to a thickness of 2 μm on the resin surface and dried.

Next, the unexposed cylinder plate coated with a thin film was exposed to the Metsutenheimer baking material (light source: high pressure mercury lamp 90W/a) for 2 hours.
Expose for a minute.

After exposure, rubber photoresist (0MR-8 manufactured by Tokyo Ohka Co., Ltd.
3) Spraying (solvent: xylene) is performed for 3 minutes, and rinsing (solvent: butyl acetate) is performed for 1 minute using the same spray.

Next, before developing the photosensitive polyamide resin, the pinholes in the rubber photoresist (Ex. OMR-83) are covered with varnish.

After varnishing, spraying phenomenon of photosensitive polyamide resin (ethanol 80% dihydrate 20%; 30℃; 3.6k9/Cl
1) for 1 minute and rinse with spray (ethanol)
Do this for 158 minutes.

Finally, the varnish and rubber-based photoresist are removed using toluene, torculene, 0-dichlorobenzene, or the like.

After peeling, drying, post-exposure, and baking, the result was 1 (
4) An endless plate with a cell depth of 40 microns was obtained with a line halftone density of %.

As a result of gravure printing using the plate thus obtained, it was possible to obtain clear images without pinholes.

Furthermore, the image quality was satisfactory compared to that produced by conventional metal printing plate cylinders.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing an example of failure in the manufacturing method of a gravure printing plate. FIG. 2 is a process diagram showing an example of a method for manufacturing a gravure printing plate according to the present invention. 10...Polyamide-based photosensitive resin layer, 12...Positive manuscript for gravure, 14...
... light, 16 ... varnish, 18 ... Zen hole, 20 ... unexposed area, 22 ... cell, 24 ... photocurable photosensitive sexual resin layer.

Claims (1)

[Scope of Claims] 1. A method for producing a resin gravure plate, characterized by sequentially performing the following steps. a Step of adhering and forming on the surface of the polyamide photosensitive resin layer another photocurable photosensitive resin layer that is not eroded by the developer of the polyamide photosensitive resin layer. b. A step of printing a positive gravure original onto the polyamide photosensitive resin layer and other photocurable photosensitive resin layers. c. A step of developing the other photocurable photosensitive resin layer with a developer that does not corrode the polyamide photosensitive resin layer. d. Covering the unexposed areas of the polyamide photosensitive resin layer that occur even though they are non-image areas and the development removal areas of other photocurable photosensitive resin layers corresponding to the unexposed areas with a protective film. Process. e A step of developing the polyamide-based photosensitive resin layer provided with the protective film with a developer that does not corrode the other photocurable photosensitive resin layer and the protective film. f. A step of removing the other photocurable photosensitive resin layer and the protective film with a removal liquid that does not corrode the polyamide photosensitive resin layer. g. A step of curing the unexposed portions of the polyamide photosensitive resin layer by post-exposure.