Lubricants with overbased calcium and overbased magnesium detergents and method for improving low-speed pre-ignition

Patent metadata

Field	Value
Publication number	US-10443011-B2
Application number	US-201715409516-A
Country	US
Kind code	B2
Filing date	Jan 18, 2017
Priority date	Jan 18, 2017
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil includes greater than 50 wt. % of a base oil, one or more overbased calcium-containing detergents, one or more overbased magnesium-containing detergents and one or more molybdenum compounds and leads to a more than 60% reduction in LSPI compared to the LSPI of a reference oil and passes the Ball Rust Test. The ratio of wt % calcium from the overbased detergents to wt. % of magnesium from the overbased detergents is less than 11.9. A ratio of total ppm of magnesium to total TBN of the lubricating oil in mg KOH/g is greater than 19. A ratio of the total ppm of calcium to the total TBN of the lubricating oil is less than 222. The oil and method may reduce low-speed pre-ignition events in a boosted internal combustion relative to commercially available lubricating oils.

First claim

What is claimed is:

1. A lubricating oil composition comprising:
greater than 50 wt. % of a base oil of lubricating viscosity, based on a total weight of the lubricating oil composition;
a sufficient amount of one or more overbased calcium-containing detergents having a total base number of greater than 225 mg KOH/g, measured by the method of ASTM D-2896, to provide greater than 1000 ppm calcium to the lubricating oil composition;
one or more overbased magnesium-containing detergents having a total base number of greater than 225 mg KOH/g, measured by the method of ASTM D-2896, wherein the total amount of magnesium provided by the one or more overbased magnesium-containing detergents to the lubricating oil composition 50-1500 ppm; and
one or more molybdenum compounds providing a total amount of molybdenum to the lubricating composition of 25-1000 ppm;
wherein a ratio of the wt. % of calcium in the lubricating oil composition from the one or more overbased calcium-containing detergents to the wt. % of magnesium in the lubricating oil composition from the one or more overbased magnesium-containing detergents is less than 11.9;
a ratio of the total ppm of magnesium in the lubricating oil composition to the total TBN of the lubricating oil composition in mg KOH/g of the lubricating oil composition, measured by the method of ASTM D-2896, is greater than 19; and
a ratio of the total ppm of calcium in the lubricating oil composition to the total TBN of the lubricating oil composition in mg KOH/g of the lubricating oil composition, measured by the method of ASTM D-2896, is less than 222.

2. The lubricating oil composition of claim 1 , wherein the one or more overbased calcium-containing detergents comprise detergents selected from calcium sulfonate and calcium phenate detergents.

3. The lubricating oil composition of claim 1 , wherein the one or more overbased magnesium-containing detergents comprises a magnesium sulfonate detergent.

4. The lubricating oil composition of claim 3 , wherein the ratio of the wt. % of calcium in the lubricating oil composition from the one or more overbased calcium-containing detergents to the wt. % of magnesium in the lubricating oil composition from the one or more overbased magnesium-containing detergents is less than 10.

5. The lubricating oil composition of claim 3 , wherein the ratio of the wt. % of calcium in the lubricating oil composition from the one or more overbased calcium-containing detergents to the wt. % of magnesium in the lubricating oil composition from the one or more overbased magnesium-containing detergents is from 0.5 to 9.

6. The lubricating oil composition of claim 3 , wherein the ratio of the total ppm of magnesium in the lubricating oil composition to the total TBN of the lubricating oil composition in mg KOH/g of the lubricating oil composition, measured by the method of ASTM D-2896, is greater than 25.

7. The lubricating oil composition of claim 3 , wherein the a ratio of the total ppm of magnesium in the lubricating oil composition to the total TBN of the lubricating oil composition in mg KOH/g of the lubricating oil composition, measured by the method of ASTM D-2896, is from 30-90.

8. The lubricating oil composition of claim 2 , wherein the ratio of the total ppm of calcium in the lubricating oil composition to the total TBN of the lubricating oil composition in mg KOH/g of the lubricating oil composition, measured by the method of ASTM D-2896, is less than 215.

9. The lubricating oil composition of claim 2 , wherein the ratio of the total ppm of calcium in the lubricating oil composition to the total TBN of the lubricating oil composition in mg KOH/g of the lubricating oil composition, measured by the method of ASTM D-2896, is from 125-210.

10. The lubricating oil composition of claim 3 , wherein the amount of one or more overbased calcium-containing detergents provides greater than 1000 ppm to less than 2000 ppm calcium to the lubricating oil composition.

11. The lubricating oil composition of claim 3 , wherein the amount of one or more overbased calcium-containing detergents provides from 1050 ppm to 1900 ppm calcium to the lubricating oil composition.

12. The lubricating oil composition of claim 3 , wherein the one or more overbased magnesium-containing detergents provide 100-1200 ppm of magnesium to the lubricating oil composition.

13. The lubricating oil composition of claim 3 , wherein the one or more overbased magnesium-containing detergents provide 200-800 ppm of magnesium to the lubricating oil composition.

14. The lubricating oil composition of claim 3 , wherein the one or more molybdenum compounds provide 50-800 ppm of molybdenum to the lubricating composition.

15. The lubricating oil composition of claim 1 , wherein boron is present in the lubricating oil composition in an amount of from 150 to 600 ppm, based on a total weight of the lubricating oil composition.

16. The lubricating oil composition of claim 2 , wherein the one or more overbased calcium sulfonate detergents has a total base number of at least 250 mg KOH/g.

17. The lubricating oil composition of claim 1 , wherein the lubricating oil composition has a total base number of less than 10 mg KOH/g of the lubricating oil composition, as measured by the method of ASTM D-2896.

18. The lubricating oil composition of claim 1 , wherein the TBN contributed to the lubricating oil composition by the one or more calcium-containing detergents is from 2.5-5.0 mg KOH/g of the lubricating oil composition, as measured by the method of ASTM D-2896.

19. The lubricating oil composition of claim 1 , wherein the TBN contributed to the lubricating oil composition by a combination of the one or more calcium-containing detergents and the one or more magnesium-containing detergents is from 4.0-8.0 mg KOH/g of the lubricating oil composition, as measured by the method of ASTM D-2896.

20. The lubricating oil composition of claim 1 , further comprising one or more components selected from the group consisting of friction modifiers, antiwear agents, dispersants, antioxidants, and viscosity index improvers.

21. The lubricating oil composition of claim 1 , wherein the greater than 50 wt. % of the base oil is selected from the group consisting of Group II, Group III, Group IV, Group V base oils, and a combination of two or more of the foregoing, and wherein the greater than 50 wt. % of the base oil is other than diluent oils that arise from provision of additive components or viscosity index improvers to the lubrication oil composition.

22. A method for reducing a number of low-speed pre-ignition events in a boosted internal combustion engine comprising steps of:
lubricating a boosted internal combustion engine with a lubricating oil composition as claimed in claim 1 , and
operating the engine lubricated with the lubricating oil composition.

23. The method of claim 22 , wherein the lubricating step lubricates a combustion chamber or cylinder walls of a spark-ignited direct injection engine provided with a turbocharger or a supercharger or a spark-ignited port fuel injection internal combustion engine provided with a turbocharger or a supercharger.

24. The method of claim 23 , further comprising a step of measuring the number of low-speed pre-ignition events of the internal combustion engine lubricated with the lubricating oil composition.

25. The lubricating oil composition of claim 1 , wherein the lubricating oil composition i

Assignees

• Fletcher Kristin
• Dingwell Lisa
• Afton Chemical Corp

Inventors

• Fletcher Kristin
• Dingwell Lisa

Classifications

• C10N2040/255

  Gasoline engines · CPC title

• C10N2030/04

  Detergent property or dispersant property · CPC title

• C10N2030/00

  Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives · CPC title

• C10N2040/25

  Internal-combustion engines · CPC title

• C10N2030/52

  Base number [TBN] · CPC title