(19)

(11)

EP 0 652 853 A1

(12)

(43) Date of publication: 17.05.1995 Bulletin 1995/20 (21) Application number: 93917977.0 (22) Date of filing: 03.08.1993

(51) International Patent Classification (IPC):  C02F 3/ 12( . ) C02F 11/ 00( . ) C02F 3/ 34( . ) C02F 11/ 18( . ) (86) International application number: PCT/GB1993/001637 (87) International publication number: WO 1994/003403 (17.02.1994 Gazette 1994/05)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 03.08.1992 GB 19920016457 (71) Applicant: WRC PLC Marlow, Buckinghamshire SL7 2HD (GB)	(72) Inventor: HOBSON, John, Andrew 69 Avon Road Wiltshire SN10 1PS (GB) (74) Representative: Wain, Christopher Paul, et al  A.A. THORNTON & CO. Northumberland House 303-306 High Holborn London WC1V 7LE London WC1V 7LE (GB)