| (19) |
 |
|
(11) |
EP 1 803 797 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
28.07.2010 Bulletin 2010/30 |
| (43) |
Date of publication A2: |
|
04.07.2007 Bulletin 2007/27 |
| (22) |
Date of filing: 27.12.2006 |
|
| (51) |
International Patent Classification (IPC):
|
|
| (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 LV MC NL PL PT RO SE
SI SK TR |
|
Designated Extension States: |
|
AL BA HR MK RS |
| (30) |
Priority: |
27.12.2005 JP 2005375974
|
| (71) |
Applicant: Chevron Japan Ltd. |
|
10th Floor, 1-1 Kanda, Suda-cho
Chiyoda-ku,
Tokyo 101-0041 (JP) |
|
| (72) |
Inventors: |
|
- Takeuchi, Yoshitaka
Haibara-gun, Shizuoka (JP)
- Yamashita, Yoshito
Omaezaki-shi, Shizuoka (JP)
- Nakazato, Morikuni
Omaezaki-shi, Shizuoka (JP)
|
| (74) |
Representative: Nash, David Allan |
|
Haseltine Lake LLP
Redcliff Quay
120 Redcliff Street
Bristol
BS1 6HU
Bristol
BS1 6HU (GB) |
|
| |
|
| (54) |
A method of improving the acrylic rubber sealant compatability in an internal combustion
engine |
(57) It has been discovered that a lubricating oil composition containing a certain combination
of a nitrogen-containing dispersant and a metal-containing detergent of an alkali
metal salt of alkylphenol derivative having a Mannich base structure, together with
a phosphorus-containing organic compound, can be effectively employed in a method
for improving the acrylic rubber sealant compatibility in an internal combustion engine,
if the ratio of the nitrogen-containing dispersant and a metal-containing detergent
of an alkali metal salt of alkylphenol derivative having a Mannich base structure
is adjusted to a specific range, i.e., in the range of from 1:0.005 to 1:2 in terms
of the nitrogen content.