Hoechst Aktiengesellschaft

Gerhard Usbeck

Dieter Mohr

Werner Frass

Engelbert Pliefke

Walter Herwig

A process is disclosed for manufacturing sheets, foils, or strips which involves chemically, mechanically, and/or electrochemically roughening and anodically oxidizing aluminum or aluminum alloy surfaces, followed by two post-treatment steps. In the first step, the metal surface is treated with an aqueous alkali metal silicate solution; thereafter, the surface is treated with an aqueous solution comprising alkaline earth metal ions. The materials produced according to this process are particularly used as supports for offset-printing plates.

Process for treating aluminum oxide layers and use in the manufacture of

The invention relates to a new phosphorus-containing polymer, polyvinylmethylphosphinic acid. It is prepared by polymerization, preferably catalytic, of vinylmethylphosphinic acid or a salt thereof. The new polymer possesses valuable properties and is used, in particular, in the production of offset printing plates which have a light-sensitive layer.

Polyvinylmethylphosphinic acid, process for its manufacture and use

This invention relates to an improvement in the process for anodically oxidizing materials in the form of strips, foils, or sheets composed of aluminum or aluminum alloys in an aqueous electrolyte containing sulfuric acid and phosphoric acid, if appropriate, after a previous mechanical, chemical or electrochemical roughening, the improvement which comprises anodically oxidizing the material in an electrolyte having a concentration of sulfuric acid ranging from about 25 to 150 g per liter, of phosphoric acid ranging from about 10 to 50 g per liter, and of aluminum ions ranging from about 5 to 25 g per liter, at a current density ranging from about 4 to 25 A/dm.sup.2, and a temperature ranging from about 25.degree. to 65.degree. C.

Process for anodically oxidizing aluminum and use of the material so

This invention relates to an improvement in the process for anodically oxidizing materials in the form of strips, foils, or plates comprised of aluminum or aluminum alloys in an aqueous electrolyte containing sulfuric acid and aluminum ions, if appropriate, after a foregoing mechanical, chemical, or electrochemical roughening, the improvement comprising anodically oxidizing the material in an electrolyte having a concentration of sulfuric acid in the range of about 25 to 100 g per liter and of aluminum ions in the range of about 10 to 25 g per liter, at a current density in the range of about 4 to 25 A/dm.sup.2, and a temperature in the range of about 25.degree. to 65.degree. C.

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Wiesbaden, Germany

Gerhard Usbeck