Lubricant composition for internal combustion engine

Patent metadata

Field	Value
Publication number	US-9587200-B2
Application number	US-201314417874-A
Country	US
Kind code	B2
Filing date	Jul 30, 2013
Priority date	Jul 31, 2012
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A lubricating oil composition of the present invention for an internal combustion engine is prepared by blending (A) a perbasic calcium sulfonate and/or a perbasic calcium phenate having a TBN of 200 mgKOH/g or higher, (B) predetermined binuclear and/or trinuclear organic molybdenum compounds, and (C) a polyalkyl (meth)acrylate having an SSI of 30 or lower into a lubricating base oil composed of a mineral oil and/or a synthetic oil, in which the total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds is 0.025% by mass or higher based on the total amount of the composition, and in which the lubricating oil composition has a high-temperature high-shear viscosity at 100° C. of 4.0 to 5.0 mPa·s, a high-temperature high-shear viscosity at 150° C. of 2.5 mPa·s or lower and a NOACK value (250° C., 1 hr) of 15% by mass or less.

First claim

The invention claimed is:

1. A lubricating oil composition for an internal combustion engine, prepared by blending:
(A) 1.0 to 3.0% by mass of a perbasic calcium sulfonate, a perbasic calcium phenate, or both, having a total base number, as measured by a perchloric acid method, of 200 mg KOH/g to 500 mg KOH/g, relative to a total mass of the lubricating oil composition;
(B) a binuclear organic molybdenum compound represented by general formula (I) below, a trinuclear organic molybdenum compound represented by general formula (II) below, or both:
Mo 3 S k L n Q z   (II),

(C) 5 to 15% by mass of a polyalkyl (meth)acrylate having an SSI ranging from 1 to 20; and
(D) an amine antioxidant and a phenol antioxidant,

relative to the total mass of the lubricating oil composition, into a lubricating base oil comprising at least one of a mineral oil and a synthetic oil,
wherein:
a total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds is 0.025% by mass or higher, and a content of all organic molybdenum compounds blended in the composition ranges from 0.04% to 0.1% by mass in terms of molybdenum content, based on the total amount of the composition;
the lubricating oil composition has
a high-temperature high-shear viscosity at 100° C. of 4.0 to 5.0 mPa·s,
a high-temperature high-shear viscosity at 150° C. of 2.0 to 2.5 mPa·s, and
a NOACK value (250° C., 1 hr) of 15% by mass or less;

the lubricating oil composition exhibits all of the following properties
a motor driving torque of less than or equal to 9.11 N·m when the lubricating oil composition is used to lubricate a single overhead cam engine with a 2 L displacement operating at a camshaft rotational speed of 550 rpm at lubricating oil temperature of 100° C.,
a kinematic viscosity at 100° C. of equal to or more than 6.10 mm 2 /s after applying a shear to the lubricating oil composition 30 times in a diesel injector, and
a rate of increase in kinematic viscosity at 40° C. of less than or equal to 41% when the lubricating oil composition is subjected to high temperature oxidation according to the method NOACK (250° C., 4 hrs);

R 1 to R 4 represent a C 4 to C 22 hydrocarbon group and may be identical to or different from each other;
X 1 to X 4 each represents a sulfur atom or oxygen atom;
L independently represents a ligand having an organic group containing a carbon atom and at least 21 carbon atoms are present in total in all the organic groups of the ligands;
n is from 1 to 4;
k is from 4 to 7;
Q represents a neutral electron donating compound; and
z is from 0 to 5 and includes non-stoichiometric values.

2. The lubricating oil composition according to claim 1 , wherein the content of all organic molybdenum compounds blended in the composition ranges from 0.05% to 0.09% by mass in terms of the molybdenum content based on the total amount of the composition.

3. The lubricating oil composition according to claim 1 , wherein the polyalkyl (meth)acrylate is blended in an amount of 7.3% to 9.0% by mass based on the total amount of the composition.

4. The lubricating oil composition according to claim 1 , wherein the high-temperature high-shear viscosity at 150° C. ranges from 2.30 to 2.42 mPa·s.

5. The lubricating oil composition according to claim 1 , wherein the high-temperature high-shear viscosity at 100° C. ranges from 4.0 to 4.75 mPa·s.

6. The lubricating oil composition according to claim 1 , wherein the NOACK value (250° C., 1 hr) ranges from 10% by mass to 15% by mass.

7. The lubricating oil composition according to claim 1 , the total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds ranges from 0.025% to 0.1% by mass based on the total amount of the composition.

8. The lubricating oil composition according to claim 1 , comprising the binuclear organic molybdenum compound represented by general formula (I).

9. The lubricating oil composition according to claim 1 , comprising the trinuclear organic molybdenum compound represented by general formula (II).

10. The lubricating oil composition according to claim 1 , comprising the binuclear organic molybdenum compound represented by general formula (I) and the trinuclear organic molybdenum compound represented by general formula (II).

11. The lubricating oil composition according to claim 1 , wherein the lubricating base oil has a kinematic viscosity at 100° C. ranging from 2.0 to 10 mm 2 /s.

12. The lubricating oil composition according to claim 1 , wherein the lubricating base oil has a kinematic viscosity at 100° C. ranging from 2.2 to 6.5 mm 2 /s.

13. The lubricating oil composition according to claim 1 , wherein the lubricating base oil has a viscosity index of 100 or higher.

14. The lubricating oil composition according to claim 1 , comprising the binuclear organic molybdenum compound represented by general formula (I), wherein R 1 to R 4 independently represent a C 4 to C 18 hydrocarbon group.

15. The lubricating oil composition according to claim 1 , comprising the binuclear organic molybdenum compound represented by general formula (I), wherein X 1 to X 4 all represent an oxygen atom.

16. The lubricating oil composition according to claim 1 , further comprising a mononuclear molybdenum compound, wherein a total content of molybdenum derived from the mononuclear molybdenum compound ranges from 0.015% to 0.07% by mass, relative to a total mass of the lubricating oil composition.

17. The lubricating oil composition according to claim 16 , wherein the total content of the molybdenum derived from the binuclear and trinuclear organic molybdenum compounds ranges from 0.025% to 0.05% by mass based on the total amount of the composition.

18. The lubricating oil composition according to claim 1 , wherein:
the lubricating oil composition does not contain a mononuclear organic molybdenum compound; and
the total content of the molybdenum derived from the binuclear and trinuclear organic molybdenum compounds ranges from 0.04% to 0.1% by mass based on the total amount of the composition.

19. The lubricating oil composition according to claim 1 , wherein the lubricating oil composition exhibits all of the following properties:
a motor driving torque ranging from 8.81 N·m to 9.11 N·m when the lubricating oil composition is used to lubricate a single overhead cam engine with a 2 L displacement operating at a camshaft rotational speed of 550 rpm at lubricating oil temperature of 100° C.;
a kinematic viscosity at 100° C. ranging from 6.10 to 6.48 mm 2 /s after applying a shear to the lubricating oil composition 30 times in a diesel injector; and
a rate of increase in kinematic viscosity at 40° C. ranging from 33% to 41% when the lubricating oil composition is subjected to high temperature oxidation according to the method NOACK (250° C., 4 hrs).

20. The lubricating oil composition according to claim 16 , wherein:
the mononuclear molybdenum compound is a compound of formula (III), a compound of formula (IV), or a mixture thereof:

and
R represents a fatty oil residue of a fatty acid comprising at least 12 carbon atoms.

Assignees

• Idemitsu Kosan Co

Inventors

• Utaka Toshimasa
• Kamano Hideki

Classifications

• C10N2030/02

  Pour-point; Viscosity index · CPC title

• C10M2207/289

  containing free hydroxy groups · CPC title

• C10N2010/12

  Groups 6 or 16 · CPC title

• C10M2209/084

  Acrylate; Methacrylate · CPC title

• C10M169/04 Primary

  Mixtures of base-materials and additives · CPC title