US 7,572,328 B2
Fast drying gypsum products
Dennis M. Lettkeman, Watonga, Okla. (US); Qingxia Liu, Vernon Hills, Ill. (US); John W. Wilson, Fairview, Okla. (US); Brian S. Randall, Fairview, Okla. (US); David R. Blackburn, Barrington, Ill. (US); and Michael P. Shake, Johnsburg, Ill. (US)
Assigned to United States Gypsum Company, Chicago, Ill. (US)
Filed on Jun. 14, 2005, as Appl. No. 11/152,661.
Prior Publication US 2006/0281837 A1, Dec. 14, 2006
Int. Cl. C04B 11/00 (2006.01)
U.S. Cl. 106—772  [106/778; 106/823; 524/5] 9 Claims
 
1. A gypsum slurry comprising:
water;
a hydraulic material comprising at least 50% calcium sulfate hemihydrate; and
a polycarboxylate dispersant co-polymer having a molecular weight in the range of 20,000 to 80,000 Daltons, comprising a vinyl ether repeating unit, an acrylic acid repeating unit and a maleic acid repeating unit.