CS255261B1 - Process for photochemical producing of picture on synthetic and mineral materials - Google Patents

Abstract

The solution concerns a photomechanical a method of making an image on synthetic materials and mineral materials as a template for photoreproduction for needs of cartography, geodesy, printing etc., and uses ecologically and hygienically an aqueous solution polyvinyl alcohol and condensate formaldehyde with 4-diazodiphenylamine chloride, as a sensibilátor. To confirm negative a copy of the tannin aqueous solution is added with a concentration of 0.5 to 20%, based on the dry weight, with the template being invoked clean water. To invert negative copy Coloring is used for a positive image solutions consisting of organic solvents and dyes dissolved therein or dispersed pigments.

Description

The present invention relates to a photomechanical method for producing images on synthetic material substrates, for example, on translucent films intended to be used as photocopies for the purposes of cartography, geodesy, polygraphy, etc., or on translucent or opaque plates, for example gauges or control panels, scales, dials, etc. Furthermore, for making pictures on mineral materials, especially on glass, porcelain, stoneware, etc.

Up to now, images on said substrates have been made by a photomechanical route using negatively working photosensitive layers sensitized with chromate salts. The sensitivity of this layer is relatively short and generally does not exceed 24 hours. Chromate salts are carcinogenic and therefore harmful to health and hygiene. They cause occupational diseases and environmental damage. The construction of two-stage wastewater treatment plants is very demanding and requires costly investments.

The above-mentioned drawbacks are overcome by the photomechanical process of making the image of the invention, followed by curing the negative copy and inverting it by staining the solution to a positive image.

SUMMARY OF THE INVENTION The present invention is based on the use of an environmentally and hygienically harmless, negatively working light-sensitive layer according to AO No. 223 202 based on an aqueous solution of polyvinyl alcohol and a semisibilizer-formaldehyde condensate or paraformaldehyde with 4-diazodiphenylamine chloride. This negative-light-sensitive layer is developed after exposure to pure water and cured with an aqueous solution of tannin at a concentration of 0.5 to 20%, based on the total amount of dry matter.

Colorless solutions consisting of organic solvents and dyes or dispersed pigments dissolved therein are used to invert the negative copy into a positive image.

The purpose of the use of tannin is to cure the induced negative layer in order to prevent the staining solutions from leaking into it and destroying it. The hardening of the template increases its mechanical resistance during further handling in operation.

In particular, the photomechanical method of producing images according to the invention results in improved occupational and environmental hygiene while maintaining or improving all existing technological parameters of photomechanical copying, such as the resolution of printing dots, the mechanical resistance of the developing and sensitivity of the layer and finally its extended shelf life.

Example 1

Creation of a template (copy) of the autotypic net on astralon foil.

Copy solution:

934 ml distilled water 56 g polyvinyl alcohol 16 g versatine red g condensate formaldehyde + diazodiphenylamine

The copy solution is applied in a centrifuge to a cleaned astralon plate at 100 rpm. After drying at 40 ° C, the film with a light-sensitive layer, backed by a black backing, is exposed through a slide in a vacuum copier. After exposure, the kpie is induced with a stream of water of 6-25 ° C and subsequently cured in a 3% aqueous tannin bath for 1 to 5 minutes. After rinsing with water, the copy is dried. The resulting negative copy (template) is then cleaned with a solution consisting of 60 parts acetone and 40 parts decahydronaphthalene. The image is further inverted by spreading the staining solution with a cotton swab over the entire copy area. Composition of the coloring solution: 550 g of ethyl acetate, 250 g of xylene, 100 g of acetone, g of sudan black. After inversion, the hardened copy layer in a 3 * aqueous sodium or potassium hydroxide solution bath is removed from the foil.

Example 2

Making a map template on a foil.

Copy solution:

900 ml distilled water, g PVA g versatine blue g formaldehyde-diazodiphenylamine condensate • The process of making the image of Example 1, except that a coloring solution of the following composition is used for inversion: 500 g ethyl acetate, 200 g acetone, 300 g toluene, 70 g sudan black. After inversion, the copy is layered with a 4% aqueous sodium or potassium hydroxide solution.

Example 3

Making a positive image on polymethyl methacrylate (organ, glass).

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Copy solution:

926.5 ml distilled water

60.0 g of polyvinyl alcohol

10,0 g spolax green (versatin green)

3.5 g formaldehyde - diazodiphenylamine condensate 3

The process of producing the image of item 1, except that a coloring solution is used to invert the image to swell the exposed portions of the organ glass, thereby achieving a good anchorage of the coloring agent. Composition of the solution: 100 ml ethyl acetate, 130 ml trichlorethylene, 300 ml methyl chloride, 300 ml chloroform, 140 ml phenol and 30 g sudan black.

Example 4

The procedure of making an image on glass.

Copy solution:

900 ml distilled water 70 g PVA g versatine blue g formaldehyde-4-diazodiphenylamine condensate

The procedure for producing an image on the glass according to item 1. Organic solvents and dyes or pigments dissolved or dispersed therein can be used as coloring solutions. In addition, dyes based on aqueous dispersions can also be used.

The method can be advantageously used in the field of presensitization, where the coated materials can be stored for a minimum of 3 months without losing the sensitivity of the copy layer.

object of the invention

Claims (2)

object of the invention Process for photomechanical imaging of synthetic materials and mineral materials by means of a negatively working light-sensitive layer of an aqueous solution of polyvinyl alcohol and formaldehyde condensate with 4-diazodiphenylamine chloride as a sensitizing agent, characterized in that the negatively working light-sensitive layer is applied over the desired pattern induces with pure water and hardens with an aqueous solution of tannin at a concentration of 0,5 to 20%, based on the total weight of the dry matter; 2. A method according to claim 1, wherein coloring solutions consisting of organic solvents and dyes or dispersed pigments dissolved therein are used to invert the negative copy into a positive image. Severography, n. P., MOST Price 2,40 Kčs