Abstract: There is provided a flash activated hydrotalcite which, when extruded to sizes of about 1/16 inch or more, has a crush load strength of at least about 7 pounds. The process for making this extrudate includes: (a) providing a hydrotalcite compound; (b) heating said compound for less than two seconds to one or more temperatures above about 482.degree. C. (900.degree. F.); (c) cooling said heated compound; (d) collecting said cooled compound; (e) forming said compound into an extrudate; and (f) reactivating said extrudate by heating to one or more temperatures above about 400.degree. C. (752.degree. F.) for about 20 minutes or more. Further strength improvements are achieved by exposing these extrudates to steam for at least about 8 hours prior to step (f).
Type:
Grant
Filed:
September 27, 1995
Date of Patent:
September 21, 1999
Assignee:
Aluminum Company of America
Inventors:
Vito Cedro, III, John M. Stinson, Jr., Mark L. Weaver, James H. Richardson