A liquid blend of octylated phenyl-α-naphthylamine, and at least one low molecular weight aromatic ester, wherein the octylated phenyl-α-naphthylamine is present from about 15% to about 35% by weight of the blend, as well as a lubricating composition comprising a lubricant base and an amount of the blend which provides up to 2.0% by weight of the octylated phenyl-α-naphthylamine in the composition.

Described herein are methods of stabilizing the beta hydrogen of glycerol based esters by the insertion of alkoxy groups to significantly improve the thermal, oxidative, and hydrolytic stability of the ester and allow for controlling the molar density of esters bonds in the lubricants to maximize hydrolytic stability while maintaining biodegradability and further improving performance properties.

This disclosure relates to a method for improving air release and water separation in a lubricating oil. The method involves formulating a composition comprising at least one lubricating oil base stock as a major component, and one or more lubricating oil additives, as a minor component. The one or more lubricating oil additives include a mixture of antifoam agents. The mixture of antifoam agents includes at least one polysiloxane and at least one acrylate polymer. During operation of a lubricating system containing the lubricating oil, release of entrained air in the lubricating oil is improved, as determined by ASTM D-3427-15, and water separation from the lubricating oil is improved, as determined by ASTM D-1401-18b, as compared to release of entrained air and water separation achieved using a lubricating oil containing other than the mixture of antifoam agents. This disclosure also relates to lubricating oils having a mixture of antifoam agents including at least one polysiloxane and at least one acrylate polymer.

The present invention is directed to the use of poly(polyisobutylenemethacrylate) as viscosity index improving component in lubricating oil compositions. The invention is further related to lubricating oil compositions comprising poly(polyisobutylenemethacrylate) with enhanced shear stability.

A hydraulic lubricating oil composition is provided which contains a synergistic mixture of three phosphorous antiwear components in order to provide good thermal stability and good demulsibility to the lubricating oil composition.

An electrorheological fluid which comprises a dispersion medium containing fluorine atoms in an amount larger than 0 wt % but not larger than 50.0 wt % and particles for electrorheological fluid use that are contained in the dispersion medium in an amount of 10-50 vol % of the total volume of the dispersion medium and the particles, the particles comprising a sulfonic-acid-group-containing polymer having a sulfonic acid group content of 30-70 wt %.

A lubricant composition said composition comprising at least one base oil and from 1 to 70 wt % of at least one friction modifying additive, wherein the composition is such that the viscosity reversibly reduces at a pressure from 50 MPa to 3 GPa. A mechanical system comprising the lubricant composition; use of the lubricant composition and methods of reducing friction using the lubricant composition are also disclosed.

The present invention relates to a hydraulic fluid composition containing a base oil (A), an antioxidant (B) including an amine-based antioxidant (B1) and a phenol-based antioxidant (B2), and a succinimide-based compound (C), wherein the hydraulic fluid composition satisfies the following requirement (I): and is to be used for hydraulic equipment which is equipped with at least one of a wet type brake and a wet type clutch and which is selected from a construction machinery, a general industrial machinery, and a power generator, and in which a working pressure is 30 MPa or more. The hydraulic fluid composition is not only excellent in wear resistance and an effect for suppressing the sludge formation but also excellent in a braking performance or a clutch performance, even when used under a high-pressure condition.

Requirement (I): A static friction coefficient (μ.sub.s) after 1,000 cycles, as measured in conformity with the SAE No. 2 test described in JCMAS P 047:2004, is 0.100 to 0.162.

A viscosity index improver comprising a copolymer having a unit (a) derived from a maleimide monomer and a unit (b) derived from a macromonomer, wherein viscosity measured by the following method is 8000 mPa.Math.s or less. Viscosity measurement method: A solution composed of 78 mass % of a Group III base oil (viscosity index: 122, kinematic viscosity at 40° C.: 19.6 mm.sup.2/s) on the American Petroleum Institute (API) classification and 22 mass % of the copolymer is measured with a viscometer (TVB-10 manufactured by Toki Sangyo Co., Ltd., rotor: SPINDLE No. M3, rotation speed: 6 rpm) at 25° C.

Provided is a lubricating oil composition for use in turbomachinery, compressors, hydraulic equipments, or machine tools, which contains a mineral oil (A) and a synthetic oil (B) containing a polyalkylene glycol (B1) and a polyol ester (B2), in which the content of the mineral oil (A) is 5 to 95% by mass based on the total amount of the lubricating oil composition, and which is used in turbomachinery, compressors, hydraulic equipments, or machine tools. The lubricating oil composition is excellent in oxidation stability, has a strong effect of preventing sludge precipitation and has excellent water separability even in use for a long period of time in high-temperature environments.