Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.
Type:
Grant
Filed:
August 21, 1998
Date of Patent:
January 29, 2002
Assignee:
United States Gysum Company
Inventors:
Qiang Yu, Steven W. Sucech, Brent E. Groza, Raymond J. Mlinac, Frederick T. Jones, Paul J. Henkels