(19)

(11)

EP 0 413 730 A1

(12)

(43) Date of publication: 27.02.1991 Bulletin 1991/09 (21) Application number: 89905318.0 (22) Date of filing: 02.05.1989

(51) International Patent Classification (IPC):  A01N 47/ 36( . ) (86) International application number: PCT/US1989/001765 (87) International publication number: WO 1989/010694 (16.11.1989 Gazette 1989/27)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 03.05.1988 US 19880189813 13.02.1989 US 19890309639 28.03.1989 US 19890329931 (71) Applicant: E.I. DU PONT DE NEMOURS AND COMPANY Wilmington Delaware 19898 (US)	(72) Inventor: LIANG, Paul Hsiao-Tseng Wilmington, DE 19808 (US) (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)