(19)

(11)

EP 0 757 712 A1

(12)

(43) Date of publication: 12.02.1997 Bulletin 1997/07 (21) Application number: 95916764.0 (22) Date of filing: 25.04.1995

(51) International Patent Classification (IPC):  C10M 169/ 04( . ) C10N 40/ 04( . ) C10N 30/ 06( . ) (86) International application number: PCT/GB1995/000941 (87) International publication number: WO 1995/029214 (02.11.1995 Gazette 1995/47)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 26.04.1994 GB 19940008235 (71) Applicant: CASTROL LIMITED Swindon, Wiltshire SN3 1RE (GB)

(72) Inventors: MARKSON, Andrew, Jonathan Upper Basildon Reading RG8 8TA (GB) PRAGNELL, John, William, Anthony Whitchurch Hill Pangbourne RG8 7PZ (GB) EDWARDS, Mark, Anthony Binfield Berkshire RG42 4UT (GB) (74) Representative: Lewis, Pauline Therese  Burmah Castrol Trading Limited, Group Patents Department, Burmah Castrol House, Pipers Way Swindon, Wiltshire SN3 1RE Swindon, Wiltshire SN3 1RE (GB)