Lubricating oil composition for shock absorber and friction reduction method for shock absorber

Patent metadata

Field	Value
Publication number	US-2016194576-A1
Application number	US-201414911112-A
Country	US
Kind code	A1
Filing date	Aug 25, 2014
Priority date	Aug 23, 2013
Publication date	Jul 7, 2016
Grant date	—

Abstract

Provided is a lubricating oil composition for a shock absorber excellent in thermal stability and capable of reducing the friction factor for rubber. The lubricating oil composition for a shock absorber contains (A) a base oil composed of a mineral oil and/or a synthetic oil, (B) a zinc dithiophosphate represented by the following general formula (I), (C) a fatty acid amide and (D) a polyalcohol ester.

In the formula, R 1 to R 4 each independently represent at least one selected from a linear, branched or cyclic alkyl group having from 6 to 20 carbon atoms and a linear, branched or cyclic alkenyl group having from 6 to 20 carbon atoms.

First claim

1 . A lubricating oil composition, comprising (A) a base oil comprising a mineral oil and/or a synthetic oil, (B) a zinc dithiophosphate represented by formula (I), (C) a fatty acid amide and (D) a polyalcohol ester:

wherein R 1 to R 4 each independently represent at least one selected from a linear, branched or cyclic alkyl group having from 6 to 20 carbon atoms and a linear, branched or cyclic alkenyl group having from 6 to 20 carbon atoms in the general formula (I).

2 . The lubricating oil composition according to claim 1 , wherein R 1 to R 4 in the formula (I) of the zinc dithiophosphate of the component (B) are each independently at least one selected from a linear, branched or cyclic alkyl group having from 8 to 18 carbon atoms and a linear, branched or cyclic alkenyl group having from 8 to 18 carbon atoms.

3 . The lubricating oil composition according to claim 1 , which comprises the zinc dithiophosphate of the component (B) in an amount of from 0.01 to 3% by mass based on the total amount of the lubricating oil composition.

4 . The lubricating oil composition according to claim 1 , wherein a carbon number of a carboxylic acid constituting the fatty acid amide of the component (C) is from 8 to 24.

5 . The lubricating oil composition according to claim 1 , which comprises the fatty acid amide of the component (C) in an amount of from 0.01 to 3% by mass based on the total amount of the lubricating oil composition.

6 . The lubricating oil composition according to claim 1 , wherein a ratio by mass of the fatty acid amide of the component (C) to the zinc dithiophosphate of the component (B) ([content of fatty acid amide of component (C)]/[content of zinc dithiophosphate of component (B)]) in the lubricating oil composition is from 0.1 to 2.

7 . The lubricating oil composition according to claim 1 , wherein the polyalcohol ester of the component (D) is an ester of pentaerythritol.

8 . The lubricating oil composition according to claim 1 , which comprises the polyalcohol ester of the component (D) in an amount of from 0.01 to 3% by mass based on the total amount of the lubricating oil composition.

9 . The lubricating oil composition according to claim 1 , wherein a ratio by mass of the polyalcohol of the component (D) to the zinc dithiophosphate of the component (B) ([(content of polyalcohol of component (D)]/[content of zinc dithiophosphate of component (B)]) in the lubricating oil composition is from 0.1 to 3.

10 . The lubricating oil composition according to claim 1 , which has a kinematic viscosity at 40° C. of from 2 to 45 mm 2 /s.

11 . The lubricating oil composition according to claim 1 , which is suitable for use in a motorcycle.

12 . A method for reducing friction in a shock absorber, comprising adding the lubricating oil composition of claim 1 to a shock absorber.

Assignees

• Idemitsu Kosan Co

Inventors

• Sakanoue Shuichi
• Aoki Aya

Classifications

• C10M2207/289

  containing free hydroxy groups · CPC title

• C10M137/10

  Thio derivatives · CPC title

• C10M2215/082

  containing hydroxyl groups; Alkoxylated derivatives · CPC title

• C10N2030/10

  Inhibition of oxidation, e.g. anti-oxidants · CPC title

• C10N2030/06

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