The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 05, 2002
Filed:
Jun. 01, 1999
BK Giulini Chemie GmbH & Co. OHG, Ludwigshafen, DE;
Abstract
A process for coloring an unglazed ceramic with an aqueous colorant solution containing a chromium (III) coordination compound which is at least partially neutralized and stable, including (a) dissolving a carboxylic acid selected from the group consisting of acetic acid, an organic dicarboxylic acid having a general formula (COOH)—(CH ) —(COOH), where n ranges from 0 to 10, and an unsaturated, organic dicarboxylic acid in water at a temperature ranging from 40 to 60° C. to provide an aqueous solution of a carboxylic acid; (b) adding a chromium (III) compound to the aqueous solution of a carboxylic acid while stirring for a time and at a temperature effective for reaction to form an aqueous solution containing a chromium (III) coordination compound; (c) filtering the aqueous solution containing the chromium (III) coordination compound to provide a filtered aqueous solution; and (d) adjusting pH of the filtered aqueous solution to a pH ranging from 3 to 6.5 by addition of one of alkali hydroxide or ammonia to provide the aqueous colorant solution containing a chromium (III) coordination compound which is at least partially neutralized, which is stable, and which has a chromium content ranging from 5 to 10% by weight.