DE1233727B - Process for the production of pictures or printing forms - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

G03c

German class: 57 b -15

Number: 1233 727

File number: S85791IXa / 57b

Filing date: June 22, 1963

Opened on: February 2, 1967

The invention relates to a method for producing pictures or printing forms, in which a layer exposed imagewise with a bichromate and a curable binder and with an organic Solvent is developed.

It is known to obtain photocopies on metals or other materials, the surface of the same with layers of gum arabic, isinglass, albumin or polyvinyl alcohol and a bichromate or alkali chromate to coat. When such layers are exposed, they are in water and insoluble in saline solutions.

It is also known that screened clichés are produced from the layers.

In addition, it is not new to have layers of shellac sensitized for making photocopies with chromates to use that developed after exposure to water-soluble organic solvents will.

The disadvantage of the known processes is that the recording materials and the exposed ones Parts of the image do not have very high mechanical resistance.

The object of the invention is to provide a method for producing mechanically resistant images or to specify printing forms. The subject matter of the invention is based on a method of production of images or printing forms, in which a layer with a bichromate and a curable Binder is imagewise exposed and developed with an organic solvent, from and is characterized in that a dried layer of water-insoluble and organic solvents soluble zein treated with an aqueous solution of bichromate and then as known exposed and developed. According to one embodiment of the invention, an aqueous ammonium dichromate solution is used used and developed with an alcoholic solution.

The product known under the name Zein is made from corn. The zein responds, though Insoluble in water, in the dry state with the bichromate solution, especially the ammonium bichromate solution, so that photosensitive compounds are formed. A metallic substrate is coated with zein long before use, without special precautions stored and before use with a tampon soaked with bichromate treated.

The method according to the invention ensures that images or printing forms are obtained

Process for producing images
or printing forms

Applicant:

Societe Technique D'Applications
Chimiques & Physiques, Paris

Representative:

Dipl.-Ing. A. Boshart

and Dipl.-Ing. W. Jackisch, patent attorneys,
Stuttgart N, Menzelstr. 40

Named as inventor:
Jean Stamboulian, Paris

Claimed priority:

France 23 June 1962 (901 743)

those whose exposed parts of the image have a high mechanical resistance.

example 1

A grained or brushed zinc or aluminum printing plate was coated with a coating ^{liquid composed of 50 g of zein, 550 cm 3 of} ethyl alcohol, 300 cm ^{3 of} diethyl glycol and dried. Before use, this printing plate was impregnated with a 10% ammonium dichromate solution, wiped off and dried. After exposure, it was developed with a 40% strength ethyl alcoholic urea solution or a 30% strength ethyl alcoholic sodium benzoate solution.

After removing the unexposed parts of the image, the printing form was prepared in the usual way, to make the exposed parts of the image hydrophilic.

Example 2

As in Example 1, a Cu-Cr bimetal plate was treated. After developing the Printing plate washed, dried and etched. The exposed parts of the image withstood this completely strong caustic agents required to attack the chrome. Thereupon the exposed parts of the image became removed with an alcoholic alkali solution.

709 507/368

Claims (3)

Example 3 As in Example 2, an Al-Cu bimetal plate was treated and then used as a planographic printing form. Example 4 As in Example 2, a plastic plate coated with Cu was treated and then used as a printed circuit. Patent claims: 1. Process for the production of images or printing forms, in which a layer with a Bichromate and a curable binder exposed imagewise and with an organic Solvent is developed, characterized in that a dried layer of zein, which is insoluble in water and soluble in organic solvents, with an aqueous one Treated bichromate solution and then exposed and developed as known. 2. The method according to claim 1, characterized in that an aqueous ammonium dichromate solution is used. 3. The method according to claim 1, characterized in that with an alcoholic solution is being developed. Considered publications:
German Patent No. 525 534;
Ed er, "Handbuch der Photographie", 1926, Vol. IV, Part 2, pp. 78 to 82; Römpp, "Chemie-Lexikon", 1962, Vol. III, p. 5722.