Process for anodically oxidizing aluminum and use of the material so prepared as a printing plate support
AssigneeHoechst Aktiengesellschaft
InventorGerhard Usbeck
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Abstract
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.
Claims5
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.
Dependencies are inferred from the claim text.