| (19) |
 |
|
(11) |
EP 1 988 146 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
17.06.2009 Bulletin 2009/25 |
| (43) |
Date of publication A2: |
|
05.11.2008 Bulletin 2008/45 |
| (22) |
Date of filing: 26.03.2008 |
|
| (51) |
International Patent Classification (IPC):
|
|
| (84) |
Designated Contracting States: |
|
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL
PT RO SE SI SK TR |
|
Designated Extension States: |
|
AL BA MK RS |
| (30) |
Priority: |
30.04.2007 US 742435
|
| (71) |
Applicants: |
|
- Chevron U.S.A. Inc.
San Ramon, CA 94583-2324 (US)
- Chevron Oronite Company LLC
San Ramon, CA 94583-2324 (US)
|
|
| (72) |
Inventors: |
|
- Haire, Michael J.
Petaluma, CA 94952 (US)
- Schuermans, Kurt J.
9030 Mariakerke (BE)
- De Weerdt, Marc J.
9052 Machelen (BE)
|
| (74) |
Representative: Nash, David Allan |
|
Haseltine Lake LLP
Redcliff Quay
120 Redcliff Street
Bristol BS1 6HU
Bristol BS1 6HU (GB) |
|
| |
|
| (54) |
Lubricating oil composition containing alkali metal borates with improved frictional
properties |
(57) A lubricating oil composition with improved frictional and wear performance, especially
when the ratio of polysulfides is controlled, wherein said composition comprises a
major amount of an oil of lubricating viscosity, at least one alkali metal borate;
at least one dihydrocarbyl polysulfide component comprising a mixture of sulfides
and having at least 30% dihydrocarbyl tetrasulfide or higher sulfides; at least one
non-acidic phosphorus component comprised of a trihydrocarbyl phosphite; at least
one dihydrocarbyl dithiophosphate; and a phosphorus component comprising a dihydrocarbyl
phosphite component is disclosed.