(19)

(11)

EP 0 799 501 A1

(12)

(43) Date of publication: 08.10.1997 Bulletin 1997/41 (21) Application number: 95939366.0 (22) Date of filing: 11.12.1995

(51) International Patent Classification (IPC):  C01G 1/ 00( . ) H01B 12/ 06( . ) H01L 39/ 02( . ) H01L 39/ 24( . ) C01G 3/ 00( . ) H01B 13/ 00( . ) H01L 39/ 12( . ) (86) International application number: PCT/GB1995/002882 (87) International publication number: WO 1996/019835 (27.06.1996 Gazette 1996/29)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 19.12.1994 GB 19940025528 (71) Applicant: JOHNSON MATTHEY PUBLIC LIMITED COMPANY London EC1N 8JP (GB)	(72) Inventors: ABELL, John, Stuart Birmingham B17 0EU (GB) LANGHORN, Jason, Barnabas North Yorkshire YO7 1AU (GB) (74) Representative: Wishart, Ian Carmichael, et al  Patents Department Johnson Matthey Technology Centre Blounts Court Sonning Common Reading, Berks RG4 9NH Reading, Berks RG4 9NH (GB)