Lubricant oil composition

Patent metadata

Field	Value
Publication number	US-2016369201-A1
Application number	US-201515122220-A
Country	US
Kind code	A1
Filing date	Mar 4, 2015
Priority date	Mar 4, 2014
Publication date	Dec 22, 2016
Grant date	—

Abstract

Provided is a lubricating oil composition favorable for reducing friction in a sliding mechanism equipped with a piston ring and a liner, in a device having the sliding mechanism. The lubricating oil composition contains a lubricant base oil, (1) a polymethacrylate and/or an olefin copolymer having a mass-average molecular weight of 100,000 to 600,000, and (2) an ester-type ashless friction modifier and/or an amine-type ashless friction modifier, and has a shear viscosity at 150° C. of 2.3 mPa· or more and less than 3.7 mPa·s.

First claim

1 . A lubricating oil composition for use in a device having a sliding mechanism equipped with a piston ring and a liner, which comprises a lubricant base oil, (1) a polymethacrylate and/or an olefin copolymer having a mass-average molecular weight of 100,000 to 600,000, and (2) an ester-type ashless friction modifier and/or an amine-type ashless friction modifier, and has a shear viscosity at 150° C. of 2.3 mPa·s or more and less than 3.7 mPa·s.

2 . The lubricating oil composition according to claim 1 , wherein the mass-average molecular weight of the polymethacrylate and/or the olefin copolymer (1) is 200,000 to 550,000.

3 . The lubricating oil composition according to claim 1 , wherein the content of the polymethacrylate and/or the olefin copolymer (1) is 2.5% by mass or more and less than 15% by mass based on the total amount of the composition.

4 . The lubricating oil composition according to claim 1 , wherein the content of the ashless friction modifier is 0.1% by mass or more and less than 2% by mass based on the total amount of the composition.

5 . The lubricating oil composition according to claim 1 , wherein the viscosity index of the lubricant base oil is 120 or more.

6 . The lubricating oil composition according to claim 1 , wherein the phosphorus content is 0.12% by mass or less based on the total amount of the composition.

7 . The lubricating oil composition according to claim 1 , which contains a Ca-containing metallic detergent and/or a Mg-containing metallic detergent in an amount of 0.05% by mass or more and 0.30% by mass or less as a total amount of Ca and Mg based on the total amount of the composition.

8 . The lubricating oil composition according to claim 1 , which comprises polybutenylsuccinic imide and/or a boronated polybutenylsuccinic imide.

9 . The lubricating oil composition according to claim 1 , which is for internal combustion engines.

10 . The lubricating oil composition according to claim 1 , wherein the piston ring in a sliding mechanism equipped with a piston ring and a liner is one treated with chromium nitride.

11 . A method for producing the lubricating oil composition of claim 1 , which comprises a step of blending a lubricant base oil with (1) a polymethacrylate and/or a olefin copolymer having a mass-average molecular weight of 100,000 to 600,000 stated above and (2) an ester-type ashless friction modifier and/or an amine-type ashless friction modifier stated above.

12 . A method of lubricating a device having a sliding mechanism equipped with a piston ring and a liner, which comprises lubricating a device having a sliding mechanism equipped with a piston ring and a liner with the lubricating oil composition of claim 1 .

Assignees

• Idemitsu Kosan Co

Inventors

• Kasai Moritsugu
• Tamura Kazushi

Classifications

• C10N2030/02

  Pour-point; Viscosity index · CPC title

• C10M2215/28

  Amides; Imides · CPC title

• C10N2020/04

  Molecular weight; Molecular weight distribution · CPC title

• C10N2030/06

  Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure · CPC title

• C10M2207/34

  Esters having a hydrocarbon substituent of thirty or more carbon atoms, e.g. substituted succinic acid derivatives · CPC title