(19)

(11)

EP 0 923 633 A2

(12)

(43) Date of publication: 23.06.1999 Bulletin 1999/25 (21) Application number: 97924118.0 (22) Date of filing: 28.05.1997

(51) International Patent Classification (IPC):  C11D 3/ 16( . ) C11D 3/ 395( . ) C11D 3/ 39( . ) (86) International application number: PCT/GB1997/001450 (87) International publication number: WO 1997/045519 (04.12.1997 Gazette 1997/52)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE Designated Extension States: AL LT LV RO SI (30) Priority: 28.05.1996 GB 19960011062 (71) Applicant: WARWICK INTERNATIONAL GROUP LIMITED Holywell, Clwyd CH8 9HE (GB)	(72) Inventors: TOMPSETT, Stephen, James Coventry CV3 2JR (GB) TURNER, Neil, A. South Wirral L66 2HJ (GB) (74) Representative: Jones, Helen Marjorie Meredith, et al  Gill Jennings & Every, Broadgate House, 7 Eldon Street London EC2M 7LH London EC2M 7LH (GB)