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:
Jun. 23, 1987
Filed:
Feb. 18, 1986
Egon Matijevic, Potsdam, NY (US);
Paola Gherardi, Novara, IT;
Montedison S.p.A., Milan, IT;
Abstract
Spherical particles having sizes below 1 .mu.m, or at maximum of 3.04 .mu.m, a narrow size size distribution consisting, or consisting essentially, of TiO.sub.2 coated by a uniform layer having a thickness up to 400 .ANG. consisting essentially .alpha.-, or .gamma.-Fe.sub.2 O.sub.3, or magnetite, or mixtures thereof, said particles being prepared by a process consisting, or consisting essentially, in the precipitation of the oxide from Fe (III) salt solutions on the surface of solid pre-formed TiO.sub.2 particles having a narrow size distribution and a number average diameter below 1 .mu.m or .ltoreq.3 .mu.m, the Fe (III) concentration being .ltoreq.40% by weight calculated on TiO.sub.2, the pH of the suspension ranging from 1.0 to 2.8, extremes excluded, by heating the suspensions to temperatures of from 80.degree. to 100.degree. C., and by aging them under such conditions for at least 30 minutes.