(19)

(11)

EP 1 100 977 A1

(12)

(43) Date of publication: 23.05.2001 Bulletin 2001/21 (21) Application number: 99928955.6 (22) Date of filing: 07.07.1999

(51) International Patent Classification (IPC)7: C22F 1/05, C22F 1/047, C22F 1/043 (86) International application number: PCT/CA9900/618 (87) International publication number: WO 0003/052 (20.01.2000 Gazette 2000/03)

(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: 08.07.1998 US 92051 P (71) Applicant: ALCAN INTERNATIONAL LIMITED MontrealQuebec H3A 3G2 (CA)	(72) Inventors: GUPTA, Alok, Kumar Kingston, Ontario K7M 1E2 (CA) MAROIS, Pierre, Henri Kingston, Ontario K7M 4J5 (CA) (74) Representative: Gaunt, Robert John  Stevens, Hewlett & PerkinsHalton House20/23 Holborn London EC1N 2JD London EC1N 2JD (GB)