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:
Apr. 12, 1994
Filed:
Nov. 16, 1992
Constanze Prengel, Noordwijikerhout, NL;
Klaus Bernhardt, Gross-Umstadt, DE;
Merck Patent Gesellschaft mit beschrankter Haftung, Darmstadt, DE;
Abstract
The invention is interference pigments having improved covering power and high luster based on platelet-shaped substrates which, if desired, are coated with one or more films comprising one or more metal oxides and are obtainable by adding an aqueous carbon black dispersion and a solution of one or more metal salts to an aqueous suspension of the substrate at a pH suitable for hydrolysis of a film comprising the metal oxide(s) or hydroxide(s) and containing carbon black, in which the product obtained, after being separated off and, if desired, after washing and drying, is ignited at 700.degree.-900.degree. C. in an oxygen-containing atmosphere, during which carbon oxides escape.