(19)

(11)

EP 0 497 874 A1

(12)

(43) Date of publication: 12.08.1992 Bulletin 1992/33 (21) Application number: 90916592.0 (22) Date of filing: 23.10.1990

(51) International Patent Classification (IPC):  C08J 3/ 24( . ) C08J 3/ 09( . ) C08L 5/ 00( . ) C08L 33/ 24( . ) C08J 3/ 03( . ) C08J 3/ 28( . ) C08L 5/ 12( . ) (86) International application number: PCT/US1990/006142 (87) International publication number: WO 1991/005816 (02.05.1991 Gazette 1991/10)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 23.10.1989 US 19890425788 (71) Applicant: MASSACHUSETTS INSTITUTE OF TECHNOLOGY Cambridge, MA 02139 (US)	(72) Inventors: MAMADA, Akira Wakayama-shi Wakayama (JP) TANAKA, Toyoichi Wellesley, MA 02181 (US) KUNGWATCHAKUN, Dawan Bangkok 10400 (TH) IRIE, Masahiro Kasuga Fukuoka (JP) (74) Representative: Holdcroft, James Gerald, Dr., et al  Graham Watt & Co. 3 Gray's Inn Square London WC1R 5AH London WC1R 5AH (GB)