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:
Aug. 26, 1997
Filed:
Jul. 29, 1996
Applicant:
Inventors:
Attila Vass, Munich, DE;
Wolf-Dieter Schroeer, Munich, DE;
Hans-Heinrich Credner, Hohenschaeftlarn, DE;
Hildegard Fischer, Munich, DE;
Assignee:
BASF Magnetics GmbH, Mannheim, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
252 6254 ; 427128 ; 4286 / ; 428900 ;
Abstract
In the preparation of dispersions of magnetic pigments, it was found that excellent dispersion stability is achieved when compounds which are selected from the group consisting of quaternary ammonium compounds, guanidines, piperidines, alkylated or ethoxylated amines, diamines, polyamines or mixtures thereof, ethanolic KOH solutions, metal alkoxylates, Grignard compounds and certain metal hydrides are used as codispersants. The compounds are added in an amount of 0.15-4% by weight, based on the magnetic pigment.