(19)

(11)

EP 2 113 125 A2

(12)

(88) Date of publication A3: 11.12.2008 (43) Date of publication: 04.11.2009 Bulletin 2009/45 (21) Application number: 08725933.9 (22) Date of filing: 22.02.2008

(51) International Patent Classification (IPC):  H01J 9/02(2006.01) H01J 1/304(2006.01) C01B 31/02(2006.01) (86) International application number: PCT/US2008/002344 (87) International publication number: WO 2008/103439 (28.08.2008 Gazette 2008/35)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR (30) Priority: 24.02.2007 US 903260 P (71) Applicant: E. I. Du Pont de Nemours and Company Wilmington, DE 19898 (US)	(72) Inventors: ZHENG, Ming Wilmington, Delaware 19808 (US) CHENG, Lap-Tak, Andrew Newark, Delaware 19711 (US) ROACH, David, Herbert Hockessin, Delaware 19707 (US) MAHLER, Walter Wilmington, Delaware 19807 (US) (74) Representative: Towler, Philip Dean  Frank B. Dehn & Co. St Bride's House 10 Salisbury Square London EC4Y 8JD London EC4Y 8JD (GB)