(19)
(11) EP 1 577 370 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.06.2008 Bulletin 2008/23

(43) Date of publication A2:
21.09.2005 Bulletin 2005/38

(21) Application number: 05075444.9

(22) Date of filing: 24.02.2005
(51) International Patent Classification (IPC): 
C10M 163/00(2006.01)
C10M 169/04(2006.01)
 C10M 141/10(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR
Designated Extension States:
AL BA HR LV MK YU

(30) Priority: 10.03.2004 US 551886 P

(71) Applicant: Afton Chemical Corporation
Richmond, VA 23219 (US)

(72) Inventor:
  • Henly, Timothy J.
    Maidens VA 23102 (US)

(74) Representative: Dunleavy, Kevin James 
Knoble & Yoshida LLC, p/o De Vries & Metman, Overschiestraat 180
1062 XK Amsterdam
1062 XK Amsterdam (NL)

   


(54) Power transmission fluids


(57) A power transmission fluid composition for extreme pressure applications. The power transmission fluid includes a base oil, and an additive composition containing an extreme pressure performance improving amount of an ester of phosphonic acid of the formula:

where R1 is a hydrocarbyl group containing from about 8 to about 24 carbon atoms, R2 and R3 are independently selected from hydrogen and a hydrocarbyl group containing from about 1 to about 8 carbon atoms, provided that no more than one of R2 and R3 is hydrogen, a succinimide dispersant, and, optionally, a metal-based detergent. The optional detergent is substantially devoid of calcium cations.





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