SU889486A1 - Method of making an offset plate - Google Patents

Description

I

The invention relates to the printing industry and can be used in the manufacture of monometallic offset printing plates.

A known method of manufacturing monometallic offset printing plates based on carbon steel, which consists in applying a layer of a copy composition based on polyvinyl alcohol, photopolymers, etc., on the metal substrate, drying it, copying the image, developing, hydrophobing the printing fg elements. The copy layer used to make this type of form does not remain on the surface of the form and is not a carrier of the printing elements. The printing elements are created directly on the steel surface by means of its oleophilization in the corresponding solutions. The whitespace elements are formed by the chemical combination of steel with sodium silicate 1.

The disadvantage of the known method of manufacturing an offset printing plate is the low run resistance of the printing elements formed on the metal, not exceeding 100 thousand impressions.

The purpose of the invention is to increase the runnability of the form produced.

The goal is achieved in that according to the method of manufacturing an offset printing plate, which consists in applying a layer of a copier composition on a carbon steel substrate, drying it, exposing it — developing and hydrophilizing the gap elements; , Resolar resin, epoxy phenol lacquer and bottled styromal in the following ratio of components, May. %: Photosensitive orthonaphthoquinone diazid 30-35

Novolacna resin43-50

Resolna resin9-12

Epoxyphenol varnish 5-6

Bottled Styromal4-6

and the hydrophilization of the space elements is carried out with an aqueous solution containing potassium ferrocyanide and polyvinyl alcohol in the following ratio of components, May. ° / o.

Potassium ferrocyanide 5-20

Polyvinyl alcohol 0.1-0.2

WaterEverything

The method for manufacturing an offset printing plate consists of the following operations: degreasing and pickling a carbon steel plate, applying a layer of copy composition, drying it, exposing the image, developing and hydrophilizing the whitespace elements.

Example 1. A carbon steel plate is electrochemically degreased in a hot solution of 5% alkali and subjected to electrochemical etching in a solution of chlorides. After etching, the plate is treated with an inhibitor solution, washed, and a copy composition of the following composition, May, is applied to the surface of the plate. %:

Photosensitive

orthonaphthoquinone diazide 35

Novolachna. Resin43

Resolna resin12

Epoxyphenol varnish6

Bottled

styromal4

Then, the process of epoxifying and making a copy is carried out. After manifestation, the gaps are hydrophilized with an aqueous solution containing 5 wt. % potassium ferrocyanide and 0.1 wt. ° / o polyvinyl alcohol, for two minutes Then paint is applied to the printing elements and the form is coated with a protective coating. Tirazheostoyknost of the received offset printing form of 200250 thousand prints.

Example 2. A carbon steel plate was prepared as in Example 1. A copy composition of the following composition, May, was applied to the surface of the plate. /about:

Photosensitive

orthonaphthoquinone diazid 30

Novolacna resin50

Epoxyphenol varnish5

Resolna resin9

Bottled

styromal6

Then, the process of epoxifying and making a copy is carried out. After manifestation, the gaps are hydrophilized with an aqueous solution containing 20 wt. % potassium ferrocyanide and 0.2 weight. % polyvinyl alcohol for two minutes Further processing as in example 1.

Example 3 The surface preparation and composition of the copier composition as in example 1. The hydrophilization of the gaps after the development is carried out with an aqueous solution containing 12 wt. % potassium ferrocyanide and; 0.12 wt. ° / o polyvinyl alcohol.

The proposed method allows to increase the run resistance of the printed forms produced.

Claims (1)

Invention Formula A method of manufacturing an offset printing plate, consisting in applying a layer of a copier composition on a carbon steel substrate, its essence, exposing, developing and hydrophilizing gaps, in order to improve the runability of the manufactured form, the composition used 5 including photosensitive orthonaphthoquinonediazide, novolac resin, resole resin, epoxyphenol varnish and bottled styromal with the following%: the components in May. Photosensitive ortonaphthoquinondiasis d 30-35 Novolacna resin 43-50 Resol Resin 9-12 Epoxy Phenolic Varnish 5-6 Bottled styromal 4-b, and hydrophilization of the gap elements is carried out with an aqueous solution containing potassium ferrocyanide and polyvinyl alcohol in the following ratio of components, May. %: Potassium ferrocyanide 5-20 Polyvinyl alcohol 0.1 -0.2 WaterEverything Sources of information taken into account in the examination 45 1. USSR inventor's certificate in application No. 2435369/12.