(19)

(11)

EP 0 548 084 A1

(12)

(43) Date of publication: 30.06.1993 Bulletin 1993/26 (21) Application number: 91911523.0 (22) Date of filing: 30.04.1991

(51) International Patent Classification (IPC):  C03C 17/ 22( . ) C23C 14/ 08( . ) C23C 14/ 06( . ) (86) International application number: PCT/US1991/002974 (87) International publication number: WO 1991/017283 (14.11.1991 Gazette 1991/26)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 01.05.1990 US 19900517168 (71) Applicant: XYTORR CORPORATION Hilliard, OH 43026 (US)	(72) Inventors: WAN, Chong, T. Columbus, OH 43220 (US) CHAMBERS, Douglas, L. Columbus, OH 43220 (US) SUSI, Guy, T. Columbus, OH 43221 (US) (74) Representative: Witte, Alexander, Dr.-Ing., et al  Witte, Weller, Gahlert & Otten Patentanwälte Rotebühlstrasse 121 D-70178 Stuttgart D-70178 Stuttgart (DE)