(19)

(11)

EP 0 394 324 A1

(12)

(43) Date of publication: 31.10.1990 Bulletin 1990/44 (21) Application number: 89900719.0 (22) Date of filing: 23.11.1988

(51) International Patent Classification (IPC):  A01N 43/ 40( . ) A01N 57/ 20( . ) A01N 47/ 36( . ) (86) International application number: PCT/US1988/004099 (87) International publication number: WO 1989/004606 (01.06.1989 Gazette 1989/12)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 25.11.1987 US 19870125302 (71) Applicant: E.I. DU PONT DE NEMOURS AND COMPANY Wilmington Delaware 19898 (US)	(72) Inventor: CHANG, Siew, Hoong 50776 Kuala Lumpur (MY) (74) Representative: Hildyard, Edward Martin, et al  Frank B. Dehn & Co. European Patent Attorneys Imperial House 15-19 Kingsway London WC2B 6UZ London WC2B 6UZ (GB)