(19)

(11)

EP 0 620 866 A1

(12)

(43) Date of publication: 26.10.1994 Bulletin 1994/43 (21) Application number: 93901845.0 (22) Date of filing: 08.01.1993

(51) International Patent Classification (IPC):  C23C 4/ 14( . ) C23C 4/ 18( . ) (86) International application number: PCT/GB1993/000023 (87) International publication number: WO 1993/014236 (22.07.1993 Gazette 1993/18)

(84) Designated Contracting States: DE FR GB IT NL (30) Priority: 10.01.1992 GB 19920000610 24.08.1992 GB 19920018004 (71) Applicant: ALCAN ALUMINIUM UK LIMITED Buckinghamshire S19 0QB (GB)	(72) Inventor: KAY, Robert Lyme Regis, Dorset DT7 3RN (GB) (74) Representative: Wise, Stephen James, et al  c/o RAWORTH, MOSS & COOK 36 Sydenham Road Croydon, Surrey CR0 2EF Croydon, Surrey CR0 2EF (GB)