Lubricants With Calcium-Containing Detergent and Their Use for Improving Low Speed Pre-Ignition

Patent metadata

Field	Value
Publication number	US-2017015926-A1
Application number	US-201615147317-A
Country	US
Kind code	A1
Filing date	May 5, 2016
Priority date	Jul 16, 2015
Publication date	Jan 19, 2017
Grant date	—

Abstract

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition includes greater than 50 wt. % of a base oil, an overbased detergent having a TBN greater than 225 mg KOH/g and a low-based/neutral detergent having a TBN up to 175 mg KOH/g. A total amount of calcium from the overbased and low-based/neutral detergent is greater than 1100 ppm to less than 2400 ppm by weight based on a total weight of the lubricating oil composition. The lubricating oil composition and method may be effective to reduce low-speed pre-ignition events in a boosted internal combustion engine lubricated with the lubricating oil composition relative to commercially available lubricating oil compositions.

First claim

1 . A lubricating oil composition comprising:
greater than 50 wt. % of a base oil of lubricating viscosity;
at least 0.3 wt. % of an overbased detergent having a total base number of greater than 225 mg KOH/g, measured by the method of ASTM D-2896, and
at least 0.2 wt. % of a low-based/neutral detergent having a total base number of up to 175 mg KOH/g, measured by the method of ASTM D-2896, wherein a total amount of calcium from the overbased and low-based/neutral detergent ranges from greater than 1100 ppm by weight to less than 2400 ppm by weight based on a total weight of the lubricating oil composition.

2 . The lubricating oil composition of claim 1 , wherein the overbased detergent comprises an overbased calcium-containing detergent.

3 . The lubricating oil composition of claim 2 , wherein the overbased calcium-containing detergent comprises a compound selected from an overbased calcium sulfonate detergent, and an overbased calcium phenate detergent.

4 . The lubricating oil composition of claim 1 , wherein the reduction of LSPI events is a 75% or greater reduction and the LSPI events are LSPI counts during 25,000 engine cycles, wherein the engine is operated at 2000 revolutions per minute with brake mean effective pressure of 18,000 kPa.

5 . The lubricating oil composition of claim 1 , wherein the low-based/neutral detergent comprises a low-based/neutral calcium-containing detergent.

6 . The lubricating oil composition of claim 1 , wherein the low-based/neutral detergent comprises a detergent selected from the group consisting of: a calcium sulfonate detergent and a calcium phenate detergent.

7 . The lubricating oil composition of claim 1 , wherein the one or more overbased calcium-containing detergent(s) provides from about 900 to less than about 2000 ppm by weight calcium to the lubricating oil composition based on a total weight of the lubricating oil composition.

8 . The lubricating oil composition of claim 1 , wherein the lubricating oil composition has a ratio of a total mmol metal in the lubricating oil composition to a total base number of the lubricating oil composition ranging from greater than 4.5 to about 10.0.

9 . The lubricating oil composition of claim 1 , wherein the lubricating oil composition is effective to pass a TEOST 33 bench oxidation test.

10 . 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.

11 . The lubricating oil composition of claim 1 , wherein the greater than 50% of 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 base oil is other than diluent oils that arise from provision of additive components or viscosity index improvers in the composition.

12 . The lubricating oil composition of claim 1 , wherein a ratio of mmol total metal in the lubricating oil composition to TBN of lubricant is greater than 8 to less than 10 and the lubricating oil composition comprises at least 0.25 wt. % of the low-based/neutral detergent.

13 . The lubricating oil composition of claim 2 , wherein the low-based/neutral detergent comprises a low-based/neutral calcium-containing detergent and a ratio of ppm calcium by weight provided to the lubricating oil composition by the low-based/neutral calcium-containing detergent to ppm of calcium by weight provided to the lubricating oil composition by the overbased calcium-containing detergent is from 0.05 to 1.0.

14 . The lubricating oil composition of claim 2 , wherein the total calcium provided to the lubricating oil composition by the one or more overbased detergents is from 1100 ppm to 1800 ppm, by weight, based on the total weight of the lubricating oil composition.

15 . The lubricating oil composition of claim 6 , wherein the total calcium provided to the lubricating oil composition by the one or more low-based/neutral calcium-containing detergents is from 50 ppm to 1000 ppm, by weight, based on the total weight of the lubricating oil composition.

16 . The lubricating oil composition of claim 1 , wherein the lubricating oil composition is effective to reduce low-speed pre-ignition events in a boosted internal combustion engine lubricated with the lubricating oil composition relative to a number of low-speed pre-ignition events in the same engine lubricated with reference lubricating oil R-1.

17 . A method for reducing low-speed pre-ignition events in a boosted internal combustion engine comprising:
lubricating a boosted internal combustion engine with a lubricating oil composition comprising greater than 50 wt. % of a base oil of lubricating viscosity; at least 0.3 wt. % of an overbased detergent having a total base number of greater than 225 mg KOH/g, measured by the method of ASTM D-2896; and at least 0.2 wt. % of a low-based/neutral detergent having a total base number of up to 175 mg KOH/g, measured by the method of ASTM D-2896; wherein a total amount of calcium from the overbased and low-based/neutral detergent ranges from greater than 1100 ppm by weight to less than 2400 ppm by weight based on a total weight of the lubricating oil composition, and operating the engine lubricated with the lubricating oil composition.

18 . The method of claim 1718 , wherein the lubricant composition passes a TEOST 33 bench oxidation test.

19 . The method of claim 18 , wherein LSPI events are based on LSPI counts during 25,000 engine cycles, wherein the engine is operated at 2000 revolutions per minute (RPM) with brake mean effective pressure (BMEP) of 18,000 kPa and the low-speed pre-ignition events in the boosted internal combustion engine lubricated with the lubricating oil composition are reduced relative to a number of low-speed pre-ignition events in the same engine lubricated with reference lubricating oil R-1.

20 . The method of claim 19 , wherein the low-based neutral detergent comprises a calcium-containing detergent, the overbased detergent comprises a calcium-containing detergent and the overbased detergent provides from about 900 to less than about 2000 ppm by weight calcium to the lubricating oil composition based on a total weight of the lubricating oil composition.

Assignees

• Afton Chemical Corp

Inventors

• Fletcher Kristin
• Lam William Y
• Yang Kongsheng
• Styer Jeremy

Classifications

• C10M2219/042

  Sulfate esters · CPC title

• C10M2227/066

  derived from Mo or W · 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

• C10M2205/0285

  used as base material · CPC title