Lubricating oil composition for internal combustion engine

Patent metadata

Field	Value
Publication number	US-9376645-B2
Application number	US-201214376898-A
Country	US
Kind code	B2
Filing date	Nov 13, 2012
Priority date	Feb 7, 2012
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

The present invention provides a lubricating oil composition for internal combustion engines which can reduce sufficiently the friction under mixed lubricating conditions and is excellent in fuel saving properties. The lubricating oil composition comprises (A) a base oil having a 100° C. kinematic viscosity of 2 to 8 mm 2 /s and an aromatic content of 10 percent by mass or less, (B) a metallic detergent having a metal ratio of 1.01 to 3.3 overbased with an alkaline earth metal borate, and (C) an organic molybdenum compound with a molybdenum concentration of 0.01 to 0.2 percent by mass on the basis of the total mass of the composition, and having a 100° C. HTHS viscosity of 5.5 mPa·s or lower.

First claim

The invention claimed is:

1. An internal combustion engine lubricating oil composition comprising:
(A) a base oil having a 100° C. kinematic viscosity of 2 to 8 mm 2 /s and an aromatic content of 10 percent by mass or less,
(B) a metallic detergent having a metal ratio of 1.01 to 3.3 overbased with an alkaline earth metal borate, and
(C) an organic molybdenum compound with a molybdenum concentration of 0.01 to 0.2 percent by mass on the basis of the total mass of the composition, and having a 100° C. HTHS viscosity of 5.5 mPa-s or lower,
wherein Component (B) has a mass ratio (MB1/MB2) of a metal content (MB1) derived from component (B) to a boron content (MB2) derived from Component (B) of greater than 2.9 to 20.

2. The internal combustion engine lubricating oil composition according to claim 1 wherein (B) the metallic detergent overbased with an alkaline earth metal borate is an alkaline earth metal salicylate.

3. The internal combustion engine lubricating oil composition according to claim 1 wherein (B) the metallic detergent is a metallic detergent produced by overbasing a mixture of (B-1) 55 to 100 percent by mass of a metallic detergent having an alkyl or alkenyl group having 8 to 19 carbon atoms and (B-2) 0 to 45 percent by mass of a metallic detergent having an alkyl or alkenyl group having 20 to 40 carbon atoms, with an alkaline earth metal borate.

4. The internal combustion engine lubricating oil composition according to claim 1 wherein (B) the content of the metallic detergent overbased with an alkaline earth metal borate is from 0.01 to 15 percent by mass on the basis of the total mass of the lubricating oil composition.

5. The internal combustion engine lubricating oil composition according to claim 1 wherein (C) the organic molybdenum compound is sulfurized molybdenum dithiocarbamate or sulfurized oxymolybdenum dithiophosphate.

6. The internal combustion engine lubricating oil composition according to claim 1 wherein the sulfated ash content is from 0.1 to 1.5 percent by mass.

Assignees

• Jx Nippon Oil & Energy Corp

Inventors

• Yaguchi Akira
• Yagishita Kazuhiro
• Hoshino Koji
• Matsui Shigeki

Classifications

• C10M163/00

  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 title

• C10N2030/45

  Ash-less or low ash content · CPC title

• C10M2215/28

  Amides; Imides · CPC title

• C10M2209/084

  Acrylate; Methacrylate · CPC title

• C10N2040/25

  Internal-combustion engines · CPC title