(19)

(11)

EP 0 968 144 A1

(12)

(43) Date of publication: 05.01.2000 Bulletin 2000/01 (21) Application number: 97907473.9 (22) Date of filing: 17.03.1997

(51) International Patent Classification (IPC)7: C03C 25/02, G02B 6/44 (86) International application number: PCT/NL9700/135 (87) International publication number: WO 9841/483 (24.09.1998 Gazette 1998/38)

(84) Designated Contracting States: DE FR GB IT NL (71) Applicants: DSM N.V. 6411 TE Heerlen (NL) JAPAN SYNTHETIC RUBBER CO., LTD. Tokyo 104 (JP)	(72) Inventors: SUGIMOTO, Masanobu Tsukuba City 305 (JP) YAMAGUCHI, Yoshikazu Tsukuba City 305 (JP) KOMIYA, Zen Tsukuba City 305 (JP) UKACHI, Takashi Ushiku City 300-12 (JP) (74) Representative: den Hartog, Jeroen H.J.  DSM Patents & TrademarksOffice GeleenP.O. Box 9 6160 MA Geleen 6160 MA Geleen (NL)