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:
Apr. 14, 1987
Filed:
Oct. 15, 1985
Applicant:
Inventor:
David K Douden, Richfield, MN (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
4283139 ; 1062 / ; 4283166 ; 428331 ; 428402 ; 428404 ; 428406 ;
Abstract
A hollow, ceramic macrosphere or spheroid comprising a relatively smooth outer skin and cellular shell is produced in the 2-20 mm diameter range with specific gravities in the 0.2-1.2 range. The spheroids can be rendered inert to water and are stable at temperatures of 800.degree. to 1000.degree. C., depending on their composition. The porosity of the shell can be controlled through various additives and/or epoxy resin coating. The spheroids may be made from common clay and sodium silicate.