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:
Feb. 17, 1987
Filed:
Aug. 05, 1985
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
C09C / ;
U.S. Cl.
CPC ...
106304 ; 106309 ;
Abstract
A process for the preparation of a mixed-phase pigment based on iron oxide and chromium oxide by heating a mixture of the oxides, hydroxides or oxide hydroxides of iron and of chromium at from 600.degree. to 1100.degree. C. and then comminuting the product and working it up in a conventional manner. The essential feature of the invention is that a mixture of transparent .alpha.-iron oxide having an orthorhombic bipyramidal crystal structure and a chromium(III) hydroxide, which has been applied onto the transparent iron oxide by precipitation with an alkali, preferably sodium carbonate, is heated. The pigments according to the invention give deep colorations and are readily dispersible.