(19)

(11)

EP 1 034 134 A1

(12)

(43) Date of publication: 13.09.2000 Bulletin 2000/37 (21) Application number: 98952918.5 (22) Date of filing: 06.11.1998

(51) International Patent Classification (IPC)7: C01B 21/26, C01B 21/28, B01J 8/02, B01J 23/83 (86) International application number: PCT/GB9803/386 (87) International publication number: WO 9925/650 (27.05.1999 Gazette 1999/21)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 19.11.1997 GB 9724310 (71) Applicant: IMPERIAL CHEMICAL INDUSTRIES PLC London SW1P 3JF (GB)	(72) Inventors: CREWDSON, Bernard, John ThirskNorth Yorkshire YO7 4HD (GB) WARD, Andrew, Mark Stockton-on-TeesCleveland TS20 1JN (GB) DUNNE, Michael, David SaltburnCleveland TS12 1HR (GB) (74) Representative: Gratwick, Christopher et al ICI Group Intellectual PropertyPO Box 90, Wilton, Middlesbrough Cleveland TS90 8JE Cleveland TS90 8JE (GB)