| 摘要 |
<p>The present invention relates to multipurpose lubricant fluids that can be used in the various units of automotive vehicles, especially in the engine, the transmission or the hydraulic circuit and relates to a lubricating composition that comprises at least one base oil from Groups I to II, and a mixture of at least two polymers having a difference in the permanent shear stability index (PSSI), measured after a standardized KRL test of 20 hours at 100°C, of at least 25 and that has a viscosity profile such that: (a') at 100°C, before shear, the kinematic viscosity of the new lubricating composition is greater than 15.0 cSt, preferably 15.5 cSt and less than 16.3 cSt; (a) at 100°C after a Bosch test of 30 cycles according to the CEC-L-14-A-93 standard, the kinematic viscosity of the final lubricating composition is greater than 12.0 cSt, preferably in the range from 12.0 to 15.0 cSt, for an oil initially of grade 40; (b) at 100°C after a KRL test of 20 hours according to the CEC-L-45-A-99 standard, the viscosity of the lubricating composition is greater than 10.0 cSt, preferably in the range from 10.0 cSt to 12.5 cSt, for an oil initially of grade 40; and (c) at 40°C after a KRL test of 3 hours according to the CEC-L-45-A-99 standard, the test duration of which is reduced to 3 hours, the viscosity of the lubricating composition is between 61 and 75 cSt, for an oil initially of grade 40.</p> |
