(19)

(11)

EP 1 749 109 A2

(12)

(88) Date of publication A3: 13.04.2006 (43) Date of publication: 07.02.2007 Bulletin 2007/06 (21) Application number: 05744383.0 (22) Date of filing: 12.05.2005

(51) International Patent Classification (IPC):  C21C 5/32(2006.01) C21C 5/46(2006.01) (86) International application number: PCT/GB2005/001857 (87) International publication number: WO 2005/111247 (24.11.2005 Gazette 2005/47)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR (30) Priority: 14.05.2004 GB 0410835 19.11.2004 GB 0425540 (71) Applicant: THE BOC GROUP, INC. Murray Hill, New Jersey 07974 (US)

(72) Inventors: CAMERON, Andrew, Miller Derbyshire DE4 5WA (GB) RICHARDSON, Andrew, Peter Clinton, NJ 08809 (US) BATHAM, John, Kelvin Beverly East Riding Yorkshire HU17 7RF (GB) WILKINSON, Mark, A. Lincoln, MA 01773 (US) STRELBISKY, Michael, James Burlington, Ontario L7M-4E9 (CA) (74) Representative: Wickham, Michael  C/o Patent and Trademark Department The BOC Group plc Chertsey Road Windlesham Surrey GU20 6HJ Surrey GU20 6HJ (GB)