(19)

(11)

EP 0 723 472 A1

(12)

(43) Date of publication: 31.07.1996 Bulletin 1996/31 (21) Application number: 94928973.0 (22) Date of filing: 12.10.1994

(51) International Patent Classification (IPC):  B01D 15/ 00( . ) H05K 3/ 26( . ) C23G 5/ 032( . ) (86) International application number: PCT/GB1994/002223 (87) International publication number: WO 1995/010343 (20.04.1995 Gazette 1995/17)

(84) Designated Contracting States: BE CH DE ES FR GB IT LI LU NL SE (30) Priority: 13.10.1993 GB 19930021067 (71) Applicant: BP Chemicals Limited London EC2M 7BA (GB)	(72) Inventors: GALBRAITH, Douglas, Peter Hull HU4 7RP (GB) POOLE, Neil Catwick Humberside HU17 5PJ (GB) (74) Representative: Krishnan, Suryanarayana Kalyana, et al  BP INTERNATIONAL LIMITED Patents & Agreements Division Chertsey Road Sunbury-on-Thames Middlesex TW16 7LN Sunbury-on-Thames Middlesex TW16 7LN (GB)