(19)

(11)

EP 0 691 936 A1

(12)

(43) Date of publication: 17.01.1996 Bulletin 1996/03 (21) Application number: 94909194.0 (22) Date of filing: 11.03.1994

(51) International Patent Classification (IPC):  C02F 1/ 46( . ) (86) International application number: PCT/GB1994/000488 (87) International publication number: WO 1994/020420 (15.09.1994 Gazette 1994/21)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 12.03.1993 GB 19930005122 (71) Applicant: T P TECHNOLOGY PLC High Wycombe, Buckinghamshire HP11 2SB (GB)	(72) Inventor: HAYES, John Datchet, Berkshire SL3 9BY (GB) (74) Representative: Crawford, Andrew Birkby, et al  A.A. THORNTON & CO. Northumberland House 303-306 High Holborn London WC1V 7LE London WC1V 7LE (GB)