JPS592613B2 - Heihan Insatsubanno Seizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a lithographic printing plate, and its purpose is to provide a printing plate that can be made quickly and easily, and that can perform lithographic printing without using any dampening water or the like. Provides a plate-making method.

Recently, compact offset printing machines for office use have become widely used, but the conventional offset printing method requires a complicated printing machine and considerable skill, and the use of dampening water requires advanced technology. is required.

Adjustment of the dampening water, that is, if it is too little, the non-image areas will become smeared, and if it is too much, the ink will emulsify, which requires skill.

Therefore, various proposals have been made recently to develop lithographic materials that enable lithographic printing without using dampening water.

A typical method using silicone is known.

That is, by utilizing the fact that silicone has a very strong ability to absorb ink, by covering the non-printing areas with silicone, ink is applied only to the printing areas when inking.

However, these plates generally have a multilayer structure and the manufacturing process is complicated.

The present invention improves the conventional method for making a lithographic plate for use under dampening water using silicone, and provides a method that is simple and can produce an excellent plate.

In other words, a lipophilic Jugetsumori substrate is used, a desired image is formed on it using a hydrophilic resin by an appropriate method, and then heated at ℃・
Then, silicone is applied onto the substrate so that the silicone is absorbed or adhered only to the non-image areas.

In this case, since silicone is usually a solution of an organic solvent such as an aromatic hydrocarbon, even if it is applied to the entire surface, the image area is crushed and the lipophilic substrate surface is exposed (i.e., the non-image area). It is applied only to the area.

After this is heat-treated to harden the silicone layer, the hydrophilic resin in the image area is eluted and removed to expose the lipophilic resin surface of the substrate in the image area.

If the plate obtained in this way is directly inked, the ink will be applied to the image area because it is lipophilic, and the ink will not stick to the non-image area because the silicone will wipe it away, allowing it to be printed as a lithographic printing plate. It can be performed.

The lipophilic substance that can be used as the base material in the present invention may be, for example, paper, synthetic paper, metal, various plastics, glass, etc., but in terms of mechanical strength and flexibility. Plastics are good.

Examples of plastics include polyethylene, polypropylene, polyvinyl chloride and other vinyl resins, acrylic resins, polycarbonate resins, polyamide resins,
Examples include lipophilic materials such as polyester resin.

These materials are usually used in the form of a sheet having a thickness of 20 to 500 microns, preferably 50 to 200 microns, but are not particularly limited.

Examples of the hydrophilic resin forming the image area include polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methylcellulose, hydroxyethylcellulose, polyethylene oxide, casein, gelatin, carboxymethylcellulose, and gum arabic.

There is no particular limit to the film thickness of the image (but it may be determined as appropriate to normally be 500 μm or less, preferably 200 μm or less).

As the silicone, a curable silicone gum, which is commonly used, is used (and cured by heating).

Here, R in the chain may be the same or different,
These include an alkyl group, an allyl group, a halogenated alkyl group, and the like.

As is generally known, polymerizable silicone gums preferably contain catalysts to promote curing, such as tin, zinc, etc. used.

There is no particular limit to the thickness of the silicone coating, but the thickness is 0°C.
It is about 5 to 20μ, preferably about 1 to 10μ.

Note that the means for forming the image area on the substrate is kitten printing,
Copying methods and various other means can be applied.

Furthermore, the solvent for elution is not particularly limited, as long as it dissolves the above-mentioned resin material that forms it. It is advantageous because it can be done.

As described above, the method of the present invention allows plate making to be carried out extremely easily without using special materials or complicated operations, and also does not require the use of dampening water during printing. The effect is extremely strong.

Example 1 An image was drawn on a frosted polyethylene terephthalate film (100 μm) using Subark ink (water-based ink) manufactured by Barker, and after drying, a silicone solution having the following composition was applied.

KS705F (30% solution) (manufactured by Shin-Etsu Chemical Co., Ltd.) 10
0 parts CatalystPS () 4 parts Toluene 200 parts The silicone solution was rubbed off in the image area and adhered only to the non-image area.

It was heated at 130° C. for 5 minutes to form a 1 μm silicone film.

By removing the water, the hydrophilic ink in the image area was eluted and removed.

When the resulting planographic plate was mounted on a plate cylinder and offset printed without dampening water, good printed matter was obtained.

Example 2゜When the original and tracing paper are stacked and exposed using a thermal exposure machine TU-270 manufactured by Riso Kagaku Kogyo Co., Ltd., volatile matter from the printing ink in the image area of the original condenses on the tracing paper, creating a sticky latent image. is obtained.

When polyvinyl alcohol powder is sprinkled on this, it adheres only to the sticky latent image area of the image area.

This was heated and melted and fixed.

When a silicone solution having the following composition was then applied, it adhered to surfaces other than the image area.

5YL-off23 (30% solution) (manufactured by Toshi Silicone Co., Ltd.) 100 parts 5H-23K
(Catalyst) () 5 parts〃 200 parts of xylene (Heated at 150'C for 2 minutes to form a 5μ silicone film.

By draining the water, the polyvinyl alcohol in the image area was eluted and removed.

When the resulting planographic plate was mounted on a plate cylinder and offset printed without dampening water, good printed matter was obtained.

Example 3 ZnO paper (photoconductive photosensitive paper) was charged and exposed using a Nirefax manufactured by Iwasaki Tsushinki Co., Ltd., and then developed and fixed with a toner containing methyl cellulose as a binder.

A silicone solution having the following composition was applied to the thus obtained copy paper.

KE102RTV (Shin-Etsu Series: manufactured by T-7) 100 copies C
0-5 parts of atalyst RE() 200 parts of xylene was heated at 100°C for 5 minutes to form a 2μ silicone film on the non-image area.

By removing the water, the methylcellulose in the image area was eluted, and when the plate was mounted on the plate cylinder thus obtained and offset printing was performed without dampening water, good printed matter was obtained.

Claims (1)

[Claims] 1. Form desired double line areas with a hydrophilic resin on the surface of a base sheet made of a lipophilic substance, then apply silicone to the sheet surface to form a silicone layer on the non-image areas, and then apply the silicone layer to the non-print area. A method for producing a lithographic printing plate, which comprises curing by heating, and then dissolving and removing the hydrophilic resin in the image area.