(19)

(11)

EP 0 165 980 A1

(12)

(43) Date of publication: 02.01.1986 Bulletin 1986/01 (21) Application number: 85900433.0 (22) Date of filing: 18.12.1984

(51) International Patent Classification (IPC):  G03B 42/ 04( . ) G03C 3/ 00( . ) (86) International application number: PCT/US1984/002083 (87) International publication number: WO 1985/002918 (04.07.1985 Gazette 1985/15)

(84) Designated Contracting States: BE CH DE FR GB LI (30) Priority: 22.12.1983 IT 19830051208 (71) Applicant: MINNESOTA MINING AND MANUFACTURING COMPANY St. Paul, Minnesota 55133-3427 (US)	(72) Inventor: BERAUDO, Riccardo Millesimo I-Savona (IT) (74) Representative: Giannesi, Pier Giovanni  c/o 3M ITALIA S.p.A. Industrial Property Dept. I-17016 Ferrania (Savona) I-17016 Ferrania (Savona) (IT)