(19)

(11)

EP 0 620 839 A1

(12)

(43) Date of publication: 26.10.1994 Bulletin 1994/43 (21) Application number: 93900354.0 (22) Date of filing: 23.12.1992

(51) International Patent Classification (IPC):  F25B 1/ 00( . ) C07C 43/ 12( . ) C07C 19/ 08( . ) C09K 5/ 04( . ) (86) International application number: PCT/GB1992/002384 (87) International publication number: WO 1993/014175 (22.07.1993 Gazette 1993/18)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 10.01.1992 GB 19920000481 10.01.1992 GB 19920000522 (71) Applicant: IMPERIAL CHEMICAL INDUSTRIES PLC London SW1P 3JF (GB)	(72) Inventors: POWELL, Richard, LLewellyn Tarporley Cheshire CW6 9NV (GB) MORRISON, James, David Northwich Cheshire CW9 8QE (GB) (74) Representative: Oldroyd, Alan  Intellectual Property Department ICI Chemicals & Polymers Ltd P.O. Box 11 The Heath Runcorn Cheshire WA7 4QE Runcorn Cheshire WA7 4QE (GB)