(19)

(11)

EP 1 177 331 A1

(12)

(43) Date of publication: 06.02.2002 Bulletin 2002/06 (21) Application number: 00931920.3 (22) Date of filing: 02.05.2000

(51) International Patent Classification (IPC)7: C23F 11/10, C23F 11/08, C23F 11/14 (86) International application number: PCT/US0008/750 (87) International publication number: WO 0066/810 (09.11.2000 Gazette 2000/45)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE Designated Extension States: AL LT LV MK RO SI (30) Priority: 03.05.1999 US 304181 03.05.1999 US 303596 12.05.1999 US 309564 17.02.2000 US 505722 (71) Applicant: BetzDearborn Inc Trevose, PA 19053-6783 (US)	(72) Inventors: EHRHARDT, William, C. Hamilton, NJ 08690 (US) CHENG, Longchun Hopewell Township, NJ 08638 (US) STASNEY, Dawn Aston, PA 19014 (US) WHITAKER, Kim, A. Limerick, PA 19468 (US) (74) Representative: W.P. Thompson & Co.  Coopers Building, Church Street Liverpool L1 3AB Liverpool L1 3AB (GB)