Lubricating oil composition and method for reducing friction in internal combustion engines

Patent metadata

Field	Value
Publication number	US-10155915-B2
Application number	US-201615318263-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Mar 31, 2015
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

A lubricating oil composition that hardly generates precipitation attributable to a molybdenum compound under the low temperature environment and is excellent in a friction-reducing effect under the low temperature environment is provided.
The lubricating oil composition is one including (A) a lubricating base oil, (B) a molybdenum-based compound, (C) a metal-based detergent, and (D) an ester compound having one or more hydroxyl groups in a molecule thereof, wherein the metal-based detergent (C) includes (C1) a calcium detergent and (C2) a magnesium detergent, and a content of the ester compound (D) having one or more hydroxyl groups in a molecule thereof is 0.03 to 1.20 mass % on a basis of the total amount of the lubricating oil composition.

First claim

The invention claimed is:

1. A lubricating oil composition, comprising:
(A) a lubricating base oil comprising mineral oil;
(B) a molybdenum-based compound comprising a binuclear organic molybdenum compound of formula (I):

wherein
R 1 to R 4 each represents a hydrocarbon group having 4 to 22 carbon atoms,
and R 1 to R 4 may be the same as or different from each other, and
X 1 to X 4 each represents a sulfur atom or an oxygen atom;

(C) a metal-based detergent comprising (C1) a calcium detergent comprising a calcium salicylate and (C2) a magnesium detergent; and
(D) an ester compound of formula (III):

wherein:
R 10 is a hydrocarbon group having from 12 to 24 carbon atoms; and
R 11 to R 15 are each a hydrogen atom,
wherein a content of the lubricating base oil (A) is 75 mass % or more and 97 mass % or less based on a total amount of the lubricating oil composition,
wherein a content of the molybdenum compound (B) as converted into a molybdenum atom is 0.03 mass % or more and 0.12 mass % or less on a basis of the total amount of the lubricating oil composition,
wherein a content of the calcium detergent (C1) as converted into a calcium atom is 0.1 mass % or more and 0.20 mass % or less on a basis of the total amount of the lubricating oil composition,
wherein a content of the magnesium detergent (C2) as converted into a magnesium atom is 0.02 mass % or more and 0.10 mass % or less on a basis of the total amount of the lubricating oil composition, and
wherein a content of the ester compound (D) having one or more hydroxyl groups in a molecule thereof is 0.05 to 1.00 mass % on a basis of the total amount of the lubricating oil composition.

2. The lubricating oil composition according to claim 1 , wherein the magnesium detergent (C2) is one or more selected from magnesium sulfonate and magnesium salicylate.

3. The lubricating oil composition according to claim 1 , wherein a total base number of the lubricating oil composition is 5.0 mgKOH/g or more.

4. The lubricating oil composition according to claim 1 , wherein the lubricating base oil (A) is a mineral oil selected from the group consisting of a paraffin base mineral oil, an intermediate base mineral oil, a naphthene base mineral oil, a wax isomerized oil, and a mineral oil-based wax.

5. The lubricating oil composition according to claim 1 in a form suitable for use in an internal combustion engine.

6. A method for reducing friction of an internal combustion engine, comprising adding the lubricating oil composition according to claim 1 to an internal combustion engine.

7. The lubricating oil composition according to claim 1 , wherein a mass ratio of the content of the magnesium detergent (C2) as converted into a magnesium atom to the content of the calcium detergent (C1) as converted into a calcium atom [{content of the magnesium detergent (C2) as converted into a magnesium atom}/{content of the calcium detergent (C1) as converted into a calcium atom}] is 0.10 to 0.60.

8. The lubricating oil composition according to claim 1 , further comprising:
(E1) a viscosity index improver having weight average molecular weight 100,000 to 600,000,
wherein a content of the viscosity index improver is 1.386 mass % or more and 10 mass % or less based on a total amount of the lubricating oil composition.

Assignees

• Idemitsu Kosan Co

Inventors

• Tamura Kazushi

Classifications

• C10M169/048

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

• C10N2030/54

  Fuel economy · CPC title

• C10M2207/026

  with tertiary alkyl groups · CPC title

• C10M2219/086

  containing sulfur atoms bound to carbon atoms of six-membered aromatic rings · CPC title

• C10N2030/04

  Detergent property or dispersant property · CPC title