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:
Sep. 02, 1997
Filed:
Nov. 29, 1994
Applicant:
Inventors:
Jean Victor Sang, Kingston, CA;
Paul Groves, Charlbury, GB;
Robert Edward Burrell, Kingston, CA;
Gerard Flynn, Bloxham, GB;
Assignee:
Alfa Biotech SpA, Castagnetta, IT;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01G / ; B01J / ; C04B / ; C04B / ;
U.S. Cl.
CPC ...
252 6256 ; 252 6252 ; 4272133 ; 42840224 ; 435176 ; 501 12 ;
Abstract
Magnetically attractable particles comprise a core of magnetic material encapsulated in a metal oxide coating. They may be made by emulsifying an aqueous solution or dispersion of the magnetic material or precursor, and an aqueous solution or sol of a coating inorganic oxide or precursor, in an inert water-immiscible liquid. The aqueous droplets are gelled, e.g. by ammonia or an amine, recovered, and heated at 250.degree.-2000.degree. C. The resulting particles are generally smooth spheres below 100 microns in diameter and often of sub-micron size.