Idemitsu Kosan Company, Limited

Aya Aoki

Shuichi Sakanoue

A shock absorber oil composition of the invention includes a base oil: (A) at least one of phosphate, amine phosphate salt, phosphite and amine phosphite salt; (B) an amide compound; and (C) a primary amine.

Shock absorber oil composition

The lubricating oil composition for a shock absorber of the present invention contains (A) a base oil composed of a mineral oil and/or a synthetic oil, (B) a tertiary amine represented by the following general formula (I), and (C) a zinc dithiophosphate represented by the following general formula (II):  wherein Rand Reach independently represent an aliphatic hydrocarbon group having from 1 to 5 carbon atoms, and Rrepresents an aliphatic hydrocarbon group having from 12 to 24 carbon atoms in the general formula (I),  wherein Rto Reach independently represent one selected from an alkyl group and an alkenyl group each having 1 to 24 carbon atoms in the general formula (II).

Lubricating oil composition for shock absorber

A shock absorber oil composition of the invention includes a base oil: (A) at least one of phosphate, amine phosphate salt, phosphite and amine phosphite salt; (B) an amide compound; and (C) an N-substituted derivative of sarcosine.

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, Rto Reach 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.

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

Provided is a lubricating oil composition for a shock absorber, which realizes excellent riding comfort in low-temperature and high-temperature environments and can suppress worsening of riding comfort with time, which is caused by evaporation and shearing of the lubricating oil. The lubricating oil composition for a shock absorber contains (A) a base oil having a pour point of lower than &#x2212;40&#xb0; C. and a kinematic viscosity at 80&#xb0; C. of from 2.0 to 2.7 mm/s, (B-1) from 1 to 15% by mass of a polymethacrylate having a weight-average molecular weight of from 10,000 to less than 100,000, and (B-2) from 0.1 to 5% by mass of a polymethacrylate having a weight-average molecular weight of from 100,000 to 200,000.

A lubricating oil composition includes: a base oil; a component (A) that is a dialkyl hydrogen phosphite; a component (B) that is a sulfur antioxidant; and a component (C) that is a polyalkenyl succinimide. Since the lubricating oil composition of the invention exhibits an excellent lubricity to both iron metal and copper metal and an excellent heat stability, the lubricating oil composition of the invention is suitable for a shock absorber of an automobiles and the like.

Growing community of inventors

Ichihara, Japan

Aya Aoki