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:
Nov. 02, 1999
Filed:
Feb. 27, 1997
John E Halko, Okarche, OK (US);
Fran Tyler, Edmond, OK (US);
Kerr-McGee Chemical Corporation, Oklahoma City, OK (US);
Abstract
Improved coated inorganic pigments having a first coating of Al.sub.2 O.sub.3, SiO.sub.2, or optionally other oxide such as a source of P.sub.2 O.sub.5, or mixtures thereof, an optional coating of ZrO.sub.2, SnO.sub.2, TiO.sub.2, SiO.sub.2, CeO.sub.2 or mixtures thereof, and a final coating of Al.sub.2 O.sub.3 which exhibit good durability, dispersibility, and optical properties in plastic or paint compositions are disclosed. Also disclosed is a process whereby an aqueous slurry of an inorganic pigment is milled to achieve a particular particle size distribution, a first coating of Al.sub.2 O.sub.3, SiO.sub.2, or optionally other oxide such as a source of P.sub.2 O.sub.5, or mixtures thereof is precipitated onto the pigment material within a first pH range, an optional amount of ZrO.sub.2, SnO.sub.2, SiO.sub.2, TiO.sub.2, CeO.sub.2 or mixtures thereof is added to the aqueous slurry within a second pH range to obtain an optional coating over the first coating, and a final coating of Al.sub.2 O.sub.3 is added over the prior coating(s).