(19)

(11)

EP 1 370 702 A1

(12)

(43) Date of publication: 17.12.2003 Bulletin 2003/51 (21) Application number: 02706958.2 (22) Date of filing: 18.03.2002

(51) International Patent Classification (IPC)7: C22C 21/00, C22F 1/04 // F28F21:08 (86) International application number: PCT/GB0201/275 (87) International publication number: WO 0207/7307 (03.10.2002 Gazette 2002/40)

(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: 22.03.2001 GB 0107208 (71) Applicant: ALCAN INTERNATIONAL LIMITED MontrealQuebec H3A 3G2 (CA)	(72) Inventors: GRAY, Alan Banbury,Oxfordshire OX15 4BB (GB) HOWELLS, Andrew David Banbury,Oxfordshire OX16 9XN (GB) (74) Representative: Wilkinson, Stephen John  Stevens, Hewlett & Perkins1 St. Augustine's Place Bristol BS1 4UD Bristol BS1 4UD (GB)