US: On 21 June 2011 United States Gypsum Co. was assigned a patent for 'Gypsum-containing product and method for producing same.' The inventors were named as Qiang Yu, Steven W Sucech, Brent E Groza, Raymond J Mlinac, Frederick T Jones and Paul J Henkels, all from the US.
According to the abstract released by the US Patent & Trademark Office, '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 sulphate material, water and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises two or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises two or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulphate material to form a set gypsum material.'
