The present invention provides an organophosphorus compound, a preparation process and use thereof. The organophosphorus compound of the present invention has a structure as represented by the general formula (I):

##STR00001##

The groups are defined in the description. The organophosphorus compound of the present invention has prominent bearing capacity and excellent antiwear and antifriction performances, and can be used as an extreme pressure antiwear additive and used in lubricating oil and lubricating grease.

A refrigerating machine oil having a kinematic viscosity at 100° C. of 0.5 mm.sup.2/s or more and 2.5 mm.sup.2/s or less, a distillation end point in gas chromatography distillation of 380° C. or more and 450° C. or less, and a sulfur content of 0.001 mass % or more and 0.2 mass % or less.

The present invention relates to provision of an extreme pressure agent-containing grease composition using, as a thickener, a urea-based thickener, the grease composition being excellent in both torque transmitting efficiency and leakage prevention performance and also excellent in wear resistance and load resistance. The grease composition contains a base oil (A), a urea-based thickener (B), and an extreme pressure agent (C), wherein particles containing the urea-based thickener (B) in the grease composition satisfies the following requirement (I): Requirement (I): an arithmetic average particle diameter of the particles on an area basis as measured by the laser diffraction/scattering method is 2.0 μm or less, and the extreme pressure agent (C) is at least one selected from an organic metal-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a sulfur-phosphorus-based extreme pressure agent.

A lubricating oil composition for a transmission, the composition including: (A) a lubricant base oil comprising a mineral base oil and/or a synthetic base oil; and (B) a poly(meth)acrylate having a weight average molecular weight of no more than 25,000, wherein the composition has a kinematic viscosity at 100° C. of 2.5 to 4.9 mm.sup.2/s.

The present disclosure relates to a lubricant composition comprising a lubricant, a first ionic liquid which is soluble in polyalphaolefin and a second ionic liquid which is insoluble in polyalphaolefin. By using the two different ionic liquids, the technical properties of the lubricant compositions can be improved.

A lubricating composition includes at least one base oil, at least one borated dispersant, at least two antioxidants selected from amine antioxidants, phenolic antioxidants substituted with one or more linear or branched alkyl groups having from 1 to 30 carbon atoms, and mixtures thereof, and at least one phosphite polymer having the formula (I) wherein: - each of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be independently selected from the C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers and Y-OH groups; - Y is selected from C2-C40 alkylene, C2-C40 alkyl lactone, —R.sup.7— N(R.sup.8)—R.sup.9— groups, in which R.sup.7, R.sup.8 and R.sup.9 are independently selected from hydrogen, C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers; - m is an integer from 2 to 100; - n is an integer from 1 to 1000.

The invention relates to phosphorous-containing compounds useful as antiwear additive components, lubricant additive compositions and lubricant compositions each comprising such compounds, methods for making and using the same, including methods of lubricating machines and machine parts and methods of extending the useful life of elastomeric seal components of such machines.

A lubricant composition comprising an oil of lubricating viscosity and about 0.01 to about 5 percent by weight of a (thio)phosphoric acid salt (“phos-amine salt”) of at least one hydrocarbyl amine. The hydrocarbyl amine may be a hindered hydrocarbyl amine, an aromatic hydrocarbyl amine, or a combination thereof.

The present invention provides a hydraulic fluid comprising: (a) 40 to 2000 ppm by weight in terms of nitrogen content of a corrosion inhibiting agent which is one or more compounds of formula (I): ##STR00001## and/or tribologically acceptable salts thereof, wherein in formula (I): each R.sup.1 is independently a hydrocarbyl group comprising 1 to 10 carbon atoms, x is 0 to 4, each of R.sup.2 and R.sup.3 is independently hydrogen or a hydrocarbyl group comprising 1 to 20 carbon atoms, R.sup.4 is —NR.sup.5R.sup.6 or —OR.sup.7, each of R.sup.5 and R.sup.6 is independently an aryl group comprising 6 to 14 carbon atoms, optionally substituted with one or more hydrocarbyl groups comprising 1 to 20 carbon atoms, R.sup.7 is a hydrocarbyl group comprising 1 to 20 carbon atoms, and in each of said hydrocarbyl groups containing 2 or more carbon atoms, the carbon chain may, independently, optionally be interrupted by one or more ether groups; (b) 0.1 to 1% by weight of an ashless dispersant; and (c) a major amount of a base oil.

A lubricating grease for electric vehicle applications includes thickener 6% by weight (wt. %) to 12 wt. %, lubricating oil 57 wt. % to 92.98 wt. %, and surface-active ester 1 wt. % to 10 wt. %. The lubricating grease also includes additives including friction reducer and modifier 0.1 wt. % to 5 wt. %, anti-wear agent 0.1 wt. % to 5 wt. %, and a balance of extreme pressure agent, oxidation inhibitor, and corrosion inhibitor.