DE1263553B - Process for the production of multicolored signs - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

B44c

German class: 75 b-10

Number: 1263 553

File number: F 44684 VI b / 75 b

Filing date: December 12, 1964

Opening day: March 14, 1968

It is already known that multi-colored doubled or colored on the surface sheets of thermoplastics can be processed into multi-colored signs by partial treatment with solvents can. For this it is necessary to use the dissolved plastic to be continuously removed during the etching process, so that new solvent is constantly added to the solvent to be dissolved Places. In addition, the remaining plastics become undesirable due to the penetration Solvent swollen. Multi-colored signs are therefore preferred in practice mechanical processing of multi-colored relined panels.

The invention now relates to a method for the production of multicolored signs Multi-colored doubled or surface-colored plates made of polyoxymethylene by partial acid etching at least one layer using etching paste at temperatures from 40 ° C to the melting range of the Polyoxymethylene, characterized in that etching pastes are used as the etching agent Contain ammonium salts of castor oil sulfuric acid esters.

Compounds that only react as acids at elevated temperatures are suitable as etching agents Ammonium salts of castor oil sulfuric acid esters (Turkish red oil).

Thickeners are preferably added to the etchant, ζ. B. acid-resistant fillers, such as titanium dioxide, Barium sulfate, chromium III oxide and in particular fumed silica, added. The application can be done with stencils by brush or spray gun or by screen printing. In the latter case, acid-resistant fabrics, e.g. B. on Based on polyterephthalic acid esters. The usual polyamide fabrics can be used are used when ammonium salts of the castor oil sulfuric acid ester are used as the acid component will. Otherwise the application, if necessary after thickening the acids with inorganic fillers, can easily be made in conventional screen printing. The applied etchants are at Temperatures from 40 ° C. to the melting range of the polyoxymethylene, preferably in a range from 70 to 150 ° C, brought to reaction.

After cooling, the residues of the etching agent are washed out. You get signs with surprisingly sharp contours. Multi-colored signs are either represented by a repetition of the The work process or through sometimes longer work processes Etching times.

Method of making multicolored
Describe

Applicant:

Farbwerke Hoechst Aktiengesellschaft
formerly Master Lucius & Brüning,
6000 Frankfurt

Named as inventor:

Hans-Joachim Lenz,

Willi Ott,

Diethard Benkel, 6239 Lorsbach

example

On the black surface of a 1 mm thick plate made of polyoxymethylene, which consists of a 0.9 mm thick white layer and a 0.1 mm thick black layer is relined with a normal screen printing device an etching paste made from the ammonium salt of castor oil-sulfuric acid esters (Turkish red oil) with 6.5% pyrogenic silicon dioxide applied. After the order a heat treatment is carried out for 20 minutes at 140 ° C in a heating cabinet. You let it cool down and washes the residue of the etching paste with ethyl alcohol. It becomes a sharply contoured image obtained according to the screen printing stencil. The black top layer is up to the white bottom layer etched through.

Claims (1)

Claim: Process for the production of multicolored signs from multicolored doubled or surface-colored Panels made of polyoxymethylene by partial acid etching of at least one layer using etching paste at temperatures of 40 ° C to the melting range of the polyoxymethylene, characterized in that etching pastes are used as the etching agent Contain ammonium salts of castor oil sulfuric acid esters. Considered publications:
German Patent No. 900 910;
Vogel, Handbuch der Metallbeizerei, 1951, p. 456.