(19)

(11)

EP 0 096 075 A1

(12)

(43) Date of publication: 21.12.1983 Bulletin 1983/51 (21) Application number: 83900397.0 (22) Date of filing: 21.12.1982

(51) International Patent Classification (IPC):  C01F 11/ 46( . ) C04B 14/ 04( . ) C04B 11/ 024( . ) (86) International application number: PCT/US1982/001776 (87) International publication number: WO 1983/002266 (07.07.1983 Gazette 1983/16)

(84) Designated Contracting States: DE FR GB (30) Priority: 21.12.1981 US 19810332579 (71) Applicant: UNITED STATES GYPSUM COMPANY Chicago, Illinois 60606 (US)	(72) Inventors: BRUCE, Robert Byron Ont. L7p 2H1 (CA) GAYNOR, John C. Des Plaines, IL 60016 (US) PALMER, Jay W. Temple Terrace, FL 33617 (US) (74) Representative: Rowe, Eric Nielsen  Edward Evans & Co. Chancery House 53-64 Chancery Lane London WC2A 1SD London WC2A 1SD (GB)