(19)

(11)

EP 1 346 075 A1

(12)

(43) Date of publication: 24.09.2003 Bulletin 2003/39 (21) Application number: 01271462.2 (22) Date of filing: 20.12.2001

(51) International Patent Classification (IPC)7: C22F 1/047, C22C 21/06 (86) International application number: PCT/GB0105/686 (87) International publication number: WO 0205/0329 (27.06.2002 Gazette 2002/26)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 20.12.2000 GB 0031104 (71) Applicant: ALCAN INTERNATIONAL LIMITED MontrealQuebec H3A 3G2 (CA)	(72) Inventor: MAHON, Gary, John Oxon OX7 3QS (GB) (74) Representative: Wise, Stephen James et al c/o RAWORTH, MOSS & COOK36 Sydenham Road Croydon,Surrey CR0 2EF Croydon,Surrey CR0 2EF (GB)