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. 29, 1977
Filed:
Jul. 18, 1974
Applicant:
Inventors:
Peter Woditsch, Krefeld, DT;
Franz Hund, Krefeld-Bockum, DT;
Gunter Buxbaum, Krefeld-Bockum, DT;
Volker Hahnkamm, Krefeld, DT;
Ingo Pflugmacher, Meerbusch, DT;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09C / ;
U.S. Cl.
CPC ...
106304 ; 1063 / ; 252 6256 ;
Abstract
An acicular, magnetic iron oxide pigment containing about 0.05 to 5% by weight of an organo silicon compound is produced by treating iron oxide hydroxide seeds either dry or in suspension with an organo silicon compound. Preferred organo silicon compounds comprise polymethylphenylsiloxane, polydimethylsiloxane and polydiphenylsiloxane. Trivalent metal ions may subsequently be deposited. The resulting pigments show only minimal losses of coercive force during processing into magnetic tapes.