(19)

(11)

EP 0 509 057 A1

(12)

(43) Date of publication: 21.10.1992 Bulletin 1992/43 (21) Application number: 91904178.0 (22) Date of filing: 31.10.1990

(51) International Patent Classification (IPC):  D21H 17/ 66( . ) D21H 17/ 67( . ) (86) International application number: PCT/US1990/006207 (87) International publication number: WO 1992/008006 (14.05.1992 Gazette 1992/11)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (71) Applicant: PQ Corporation Valley Forge, PA 19482 (US)	(72) Inventors: PETERS, John, F. Lansdale, PA 19455 (US) KRUMRINE, Paul, H. Hatfield, PA 19440 (US) REIFSNYDER, Richard, H. Ardmore, PA 19003 (US) NEHRING, Robert, J., Jr. Hopedale, MA 01747 (US) (74) Representative: Kraus, Walter, Dr., et al  Patentanwälte Kraus, Weisert & Partner Thomas-Wimmer-Ring 15 D-80539 München D-80539 München (DE)