Hoechst Aktiengesellschaft

Walter Niderstatter

Joachim Stroszynski

Gerhard Sprintschnik

Disclosed is a process for the production of a material in the form of a plate, a foil or a strip, from aluminum or an alloy thereof, which has been chemically, mechanically and/or electrochemically roughened. The process comprises a two-stage oxidation involving a first stage (a) which is performed in an aqueous electrolyte having from about 60 to 180 g/l of phosphoric acid, at a temperature of the electrolyte bath of about 47.degree. to 70.degree. C. and at a voltage of about 36 to 80 V and a second stage (b) which is performed in an aqueous electrolyte having from about 60 to 300 g/l of sulfuric acid, at a temperature of the electrolyte bath of about 30.degree. to 65.degree. C. and at a voltage of about 15 to 35 V. Also disclosed is an offset-printing plate, having a radiation-sensitive coating and a support material produced by the process described above.

Growing community of inventors

Eltville, Germany

Walter Niderstatter