Lubricant composition comprising anti-foam agents

Patent metadata

Field	Value
Publication number	US-9309480-B2
Application number	US-201213982285-A
Country	US
Kind code	B2
Filing date	Jan 26, 2012
Priority date	Jan 31, 2011
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

The disclosed invention relates to a multigrade lubricant composition which can be used for numerous lubricant applications, but is particularly useful for lubricating a diesel engine. The lubricant composition comprises an oil of lubricating viscosity, a detergent, a dispersant, a viscosity index improver, and a combination of anti-foam agents. The lubricant composition may be used for providing enhanced fuel economy and avoiding air entrainment problems when used in lubricating diesel engines.

First claim

The invention claimed is:

1. A lubricant composition, comprising:
an oil of lubricating viscosity;
a detergent comprising an overbased calcium sulfonate, an overbased calcium phenate, or a mixture thereof;
a dispersant;
a zinc dialkyldithiophosphate;
(1) about 5 to about 50 ppm of a first anti-foam agent comprising a polydimethyl siloxane having a kinetic viscosity (absent solvent) at 25° C. in the range from about 10,000 to about 50,000 mm 2 /s (cSt);
(2) about 0.5 to about 13 ppm of a second anti-foam agent comprising a polydimethyl siloxane having a kinetic viscosity (absent solvent) at 25° C. in the range from about 80,000 to about 120,000 mm 2 /s (cSt); and
(3) about 3.7 to about 35 ppm of a third anti-foam agent comprising a fluorinated polysiloxane having a kinematic viscosity (absent solvent) at 25° C. in the range from about 50 to about 500 mm 2 /s (cSt).

2. The composition of claim 1 wherein the composition is a multigrade composition, further comprising a viscosity index improver.

3. The composition of claim 1 wherein the composition further comprises at least one of an antiwear agent, an antioxidant, a friction modifier, a pour point depressant, a metal deactivator, a corrosion inhibitor, a dispersant viscosity modifier, an extreme pressure agent, a demulsifier, a seal swelling agent, or a mixture of two or more thereof.

4. The composition of claim 1 wherein the lubricant composition has a kinematic viscosity at 100° C. of up to about 12.5 cSt.

5. The composition of claim 1 wherein the dispersant comprises a polyisobutene substituted succinimide, a borated polyisobutene substituted succinimide, or a mixture thereof.

6. The composition of claim 1 wherein the first anti-foam agent is provided to the lubricant in the form of a solution or dispersion of from about 1 to about 50% by weight of the polydimethyl siloxane in a solvent.

7. The composition of claim 6 wherein the solvent comprises a naphthenic hydrocarbon solvent.

8. The composition of claim 1 wherein the second anti-foam agent is provided to the lubricant in the form of a solution or dispersion of from about 1 to about 50% by weight of the polydimethyl siloxane in a solvent.

9. The composition of claim 8 wherein the solvent comprises a naphthenic hydrocarbon solvent.

10. The composition of claim 1 wherein the fluorinated polysiloxane of the third anti-foam agent comprises poly(3,3,3-trifluropropyl methyl siloxane).

11. The composition of claim 1 wherein the third anti-foam agent is provided to the lubricant in the form of a solution or dispersion of from about 5 to about 95% by weight of the fluorinated polysiloxane in a solvent.

12. The composition of claim 11 wherein the solvent comprises a ketone having about 5 to about 16 carbon atoms.

13. The composition of claim 1 wherein the lubricant composition has a sulfur content of about 1% by weight or less.

14. The composition of claim 1 wherein the lubricant composition has a phosphorus content of about 0.2% by weight or less.

15. The composition of claim 1 wherein the lubricant composition has a metal content as measured by sulfated ash in the range from about 0.3 to about 1.2% by weight sulfated ash.

16. A method of lubricating an engine, comprising: supplying to the engine the lubricant composition of claim 1 .

17. The method of claim 16 wherein the engine is a diesel engine having an output of at least about 750 kW (1000 horsepower).

Assignees

• Loop John G
• Abraham William D
• Lubrizol Corp

Inventors

• Loop John G
• Abraham William D

Classifications

• C10N2040/252

  Diesel engines · CPC title

• C10M2229/051

  containing halogen · CPC title

• C10M169/048

  the additives being a mixture of compounds of unknown or incompletely defined constitution, non-macromolecular and macromolecular compounds · CPC title

• C10M167/00

  Lubricating compositions characterised by the additive being a mixture of a macromolecular compound, a non-macromolecular compound and a compound of unknown or incompletely defined constitution, each of these compounds being essential · CPC title

• C10N2030/43

  Sulfur free or low sulfur content compositions · CPC title