| (19) |
 |
|
(11) |
EP 1 308 496 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
28.05.2003 Bulletin 2003/22 |
| (43) |
Date of publication A2: |
|
07.05.2003 Bulletin 2003/19 |
| (22) |
Date of filing: 05.11.2002 |
|
| (51) |
International Patent Classification (IPC)7: C10M 141/10, C10M 167/00
// (C10M141/10, 133:44, 135:36, 137:02),(C10M167/00, 125:24, 133:44, 133:52, 133:56,
135:36, 137:02, 137:10, 145:14, 159:16, 159:24), C10N30:06, C10N40:04 |
|
| (84) |
Designated Contracting States: |
|
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR |
|
Designated Extension States: |
|
AL LT LV MK RO SI |
| (30) |
Priority: |
06.11.2001 US 332932
|
| (71) |
Applicant: The Lubrizol Corporation (an Ohio corporation) |
|
Wickliffe Ohio 44092-2298 (US) |
|
| (72) |
Inventors: |
|
- Sumiejski, J.L.
Mentor, Ohio 44060 (US)
- Ward, William C.Jr.
Perry, Ohio 44081 (US)
|
| (74) |
Representative: Crisp, David Norman et al |
|
D. YOUNG & CO. 21 New Fetter Lane
London EC4A 1DA
London EC4A 1DA (GB) |
|
| |
|
| (54) |
Tramsmission fluids exhibiting reduced pitting |
(57) Compounds comprising a 5-membered ring containing at least two double bonded nitrogen
atoms can be used to impart improved metal pitting performance to a transmission fluid.
The fluid includes an oil of lubricating viscosity and a hydrocarbyl ester of a phosphorous
acid and is preferably limited to 0 to 0.1 percent by weight of zinc salts of sulfur-containing
phosphorus acids.