USE OF ESTERS IN A LUBRICANT COMPOSITION FOR IMPROVING CLEANLINESS OF AN ENGINE

Abstract

The present application relates to the use, in a lubricant composition comprising at least one base oil, of 2 to 12% by weight, relative to the weight of said lubricant composition, of an ester that has a viscosity at 100 C. of between 200 and 1000 cSt, for the purpose of improving the cleanliness of an engine.

Claims

1-8. (canceled)

9. Method for improving the cleanliness of an engine comprising the use in the engine of a lubricant composition comprising at least one base oil and 2 to 12 wt % (by weight of the lubricant composition) of an ester having a viscosity at 100 C. between 200 and 100 cST, wherein the ester is not a glycerol ester.

10. Method according to claim 9, wherein the viscosity of the ester at 100 C. is between 200 and 900 cST.

11. Method according to claim 9, wherein the ester is included in a proportion of 2 to 11 wt % by weight of the lubricant composition.

12. Method according to claim 9, wherein the alcohol forming the esters is selected from the mono- and polyalcohols.

13. Method according to claim 11, wherein the acids are selected from acid anhydrides or fatty acids.

14. Method according to claim 12, wherein the acids are selected from acid anhydrides or fatty acids.

15. Method to claim 13, wherein the carbon chain of the acid anhydrides or fatty acids is functionalized by one or more groups elected from carboxylic acids, amides, ureas, urethanes, amines, polyisobutadienes, or alcohols.

16. Method to claim 14, wherein the carbon chain of the acid anhydrides or fatty acids is functionalized by one or more groups elected from carboxylic acids, amides, ureas, urethanes, amines, polyisobutadienes, or alcohols.

17. Method according to claim 9, wherein the engine is a marine engine.

18. Method according to claim 17, wherein the engine is a 2-stroke marine engine.

Description

[0096] The temperature resistance of the compositions was thus evaluated by means of the ECBT test. A detailed description of this test can be found in the publication Research and Development of Marine Lubricants in ELF ANTAR FranceThe relevance of laboratory tests in simulating field performance, by Jean-Philippe ROMAN, MARINE PROPULSION CONFERENCE 2000AMSTERDAM29-30 MARCH 2000.

[0097] The results are shown in table 4 below.

[0098] The results show that the compositions according to the invention have good temperature resistance, and are thus able to improve engine cleanliness.

TABLE-US-00005 TABLE 4 COMPOSITIONS CI1 CI2 CI3 CI4 CI5 CI6 Score at 73.6 92.3 88.5 62.9 63.9 45.7 280 C. Critical 289 C. 289 C. 295 C. 285 C. 283 C. 282 C. temperature measured at score of 50 COMPOSITIONS CC1 CC2 CC3 CC4 CC5 CC6 Score at 32.2 40.1 34.1 28.8 12.2 47 280 C. Critical 277 C. 278 C. 277 C. 276 C. 274 C. 279 C. temperature measured at score of 50

[0099] When determining the score at 280 C., if the surface is free of coating, the score is 100. In other words, the lower the score, the more coating there is on the surface.

[0100] The critical temperature corresponds to the temperature at which the surface has a coating with a score of 50.

[0101] These results show that esters having a viscosity according to the invention allow advantageously for improvements in engine cleanliness compared to lubricant compositions lacking such esters and compared to lubricant compositions comprising esters having different viscosities. In fact, the coating score is closer to 100 with the esters according to the invention. Additionally, the critical temperature is considerably greater for the esters according to the invention.

[0102] These results also show the influence of the quantity of ester used.