(19)

(11)

EP 1 135 546 A1

(12)

(43) Date of publication: 26.09.2001 Bulletin 2001/39 (21) Application number: 99955121.1 (22) Date of filing: 22.10.1999

(51) International Patent Classification (IPC)7: C25B 15/00, C25B 11/00 (86) International application number: PCT/US9924/720 (87) International publication number: WO 0024/949 (04.05.2000 Gazette 2000/18)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE Designated Extension States: AL LT LV MK RO SI (30) Priority: 23.10.1998 US 105336 P (71) Applicant: THE DOW CHEMICAL COMPANY Midland, Michigan 48674 (US)	(72) Inventors: ZHOU, Jianqing D-21683 Stade (DE) MENSCHIG, Klaus-Ruediger Sugar Land, TX 77479 (US) (74) Representative: Patentanwälte Schaad, Balass, Menzl & Partner AG  Dufourstrasse 101Postfach 8034 Zürich 8034 Zürich (CH)