RU1771987C - Method of cleaning aluminium form plate of offset printing - Google Patents

Abstract

Use: in the printing industry for the multiple restoration of the printing properties of an aluminum offset printing plate. SUMMARY OF THE INVENTION: An aluminum offset printing plate is treated with a solution of potassium butylate in butanol at a molar ratio of 9.75: 0.75-10.25: 0.25, respectively. Processing was carried out at 50-70 ° C for 2-5 minutes. Washed with running water, dried 1 table.

Description

The invention relates to the printing industry and can be used to repeatedly restore the printing properties of an aluminum offset printing plate.

The existing method for cleaning aluminum plates of offset printing is used only for cleaning plates from an electrographic powder image that is thermally fixed and does not allow to repeatedly restore the printing properties of aluminum plate of other standard shapes. The method is time consuming and does not provide high-quality cleaning. As a solvent, an aqueous solution of trisodium phosphate is used at 80 ° C with pretreatment of the plate with acetone.

A known method selected by the applicant as a prototype, which consists in treating the surface of the plates with an active solvent as a homogeneous mixture of dioxane - water - potassium orthobenzoate with their molar ratio of components, respectively

from 10.0: 25.0: 1.0 to 10.8: 26.8: 1.0 for 10-12 minutes at 20-30 ° C, followed by washing and drying. The disadvantages of this method are the presence of a toxic solvent, the short shelf life and high cost of the solvent, the duration of the cleaning process, and the limited ability to use a cleaning agent to capture only an electrographic image.

The purpose of the invention is to expand the technological capabilities of the method by ensuring the removal of various types of copy layers while increasing its economy and improving working conditions.

This goal is achieved in that in a cleaning method comprising surface treatment with a potassium-containing solvent, washing and drying according to the invention, a solution of potassium butylate in butanol is used as a solvent at a molar ratio of respectively

9.75: 0.75-10.25: 0.25,

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and surface treatment is carried out at 70-80 ° C for 2-5 minutes.

Example 1. The removal of printing text (image) from an aluminum plate of offset printing (foil) is carried out as follows.

In a glass or steel bath corresponding to the size of the foil located in the fume hood, a solution of Kalm butylate in butyl alcohol is placed, and the foil sheets are dipped sequentially into it for 2-5 minutes with the text up at 50-70 ° C. There should be a solution layer of at least 2 cm above the foil. There is a slight release of gas bubbles and the removal of the printing text at the same time as the printing ink. Sheets of foil cleared of text in a fume hood are transferred to a bath with running water, in which the surface of the foil is wiped with a foam or gauze swab. The washed sheets of foil are dried in air in a vertical suspended state.

The treated foil retains its original granular surface, but has a lighter tone than the original, and the foil cleaning operation can be repeated up to five times without compromising the quality of the material.

The preparation of the promised agent is as follows.

740 g (10 mol) of butyl alcohol was charged into a chemical flask, 28 g (0.5 mol) of KOH was added, and the mixture was heated to a vapor temperature of 117 ° C (the aziotrope water in butyl alcohol was distilled off when heated). Then the heating is stopped, the mixture is cooled. Upon cooling, precipitation of potassium butylzine crystals was observed. For

to dissolve them, an additional amount of butyl alcohol must be added until they are completely dissolved. This forms a homogeneous yellow-orange

transparent liquid with a molar ratio of 10: 0.5.

In Examples 2 and 3, the process is conducted, as in Example 1, the difference is only in the molar ratio of the components.

Example 2. A similar mixture was prepared with a molar ratio of 10.25: 0.25.

PRI me R 3. Prepare a similar mixture with a molar ratio of components

9.75: 0.75.

The solvent can be stored without changing its properties in a closed vessel for 1 month, provided that exposure to water is excluded. The proposed method

explained in the table.

Claims (1)

SUMMARY OF THE INVENTION A method for cleaning an aluminum offset printing plate, comprising processing of its surface with a potassium-containing solvent, washing and drying, characterized in that, in order to expand the technological capabilities of the method by providing removal different types of copy layers while increasing its economy and improving working conditions, a solution of potassium butylate in butanol is used as a solvent at a molar ratio of 9.75: 0.75-10,, 25: 0.25, respectively, and surface treatment was carried out they are burnt at 50-70 ° C for 2-5 minutes.