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

• US 10,155,915 B2
• Filed: 03/30/2016
• Issued: 12/18/2018
• Est. Priority Date: 03/31/2015
• Status: Active Grant

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Tamura, Kazushi
• Primary Examiner(s): Vasisth, Vishal V
• Application Number:
  US15/318,263
• Publication Number:
  US 20170130158A1
• Time in Patent Office: 993 Days
• Field of Search: 508363, 508391, 508501
• CPC Class Codes: C10M 129/54 containing hydroxy groups
• CPC Class Codes: C10M 129/76 containing free hydroxy or carboxyl groups
• CPC Class Codes: C10M 135/10 Sulfonic acids or derivatives thereof
• CPC Class Codes: C10M 141/08 at least one of them being an organic sulfur-, selenium- or tellurium-containing compound
• CPC Class Codes: C10M 163/00 Lubricating compositions characterised by the additive being a mixture of a compound of unknown or incompletely defined constitution and a non-macromolecular compound, each of these compounds being essential
• CPC Class Codes: C10M 169/048 the additives being a mixture of compounds of unknown or incompletely defined constitution, non-macromolecular and macromolecular compounds
• CPC Class Codes: C10M 2203/003 used as base material
• CPC Class Codes: C10M 2203/1025 used as base material
• CPC Class Codes: C10M 2205/0285 used as base material
• CPC Class Codes: C10M 2207/026 with tertiary alkyl groups
• CPC Class Codes: C10M 2207/262 derived from hydroxy substituted aromatic acids, e.g. salicylates
• CPC Class Codes: C10M 2207/283 of polyhydroxy compounds
• CPC Class Codes: C10M 2207/289 containing free hydroxy groups
• CPC Class Codes: C10M 2209/084 Acrylate; Methacrylate
• CPC Class Codes: C10M 2215/064 Di- and triaryl amines
• CPC Class Codes: C10M 2215/28 Amides; Imides
• CPC Class Codes: C10M 2219/046 Overbasedsulfonic acid salts
• CPC Class Codes: C10M 2219/068 Thiocarbamate metal salts
• CPC Class Codes: C10M 2219/086 containing sulfur atoms bound to carbon atoms of six-membered aromatic rings
• CPC Class Codes: C10M 2223/045 Metal containing thio derivatives
• CPC Class Codes: C10M 2227/066 : derived from Mo or W
• CPC Class Codes: C10N 2010/04 : Groups 2 or 12
• CPC Class Codes: C10N 2010/12 : Groups 6 or 16
• CPC Class Codes: C10N 2020/02 : Viscosity; Viscosity index
• CPC Class Codes: C10N 2030/02 : Pour-point; Viscosity index
• CPC Class Codes: C10N 2030/04 : Detergent property or dispersant property
• CPC Class Codes: C10N 2030/06 : Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2030/08 : Resistance to extreme temperature
• CPC Class Codes: C10N 2030/10 : Inhibition of oxidation, e.g. anti-oxidants
• CPC Class Codes: C10N 2030/52 : Base number [TBN]
• CPC Class Codes: C10N 2030/54 : Fuel economy
• CPC Class Codes: C10N 2040/25 : Internal-combustion engines
• CPC Class Codes: C10N 2060/14 : by boron or a compound containing boron

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.

Claims

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);

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.