A lubricating oil composition for refrigerating machines contains a base oil and an additive in a form of a hydrocarbon compound having a biphenyl structure or a stilbene structure. When the present lubricating oil composition for refrigerating machines is used in refrigerating equipment such as an open-type automobile air-conditioner, an electric automobile air-conditioner, a gas heat pump, other air-conditioning equipment, a refrigerating machine, a vending machine, a showcase, a water-heating system and a refrigerating/heating system, it is possible to detect the leakage of a refrigerant with a long-lasting stability. Therefore, when an unsaturated chlorofluorocarbon refrigerant with a poor stability is used in the above-listed equipment, the present lubricating oil composition for refrigerating machines is significantly advantageous.

Lubricant compositions, core-shell nanoparticles, and related methods are disclosed. In an exemplary embodiment, a lubricant composition includes a plurality of core-shell nanoparticles. The nanoparticles include a core, a first shell disposed on the core, and a second shell disposed on the first shell. The first shell is formed from a siliceous material and the second shell is formed from a hydrophobic material. The first and second shells form functional coatings that reduce wear and friction of parts lubricated with the lubricant composition.

A method of using energy-efficient lubricant compositions to reduce wear between two surfaces exposed to a high shear condition is provided. The lubricant compositions comprise polysiloxane base oils having alkyl, aryl, or a combination of alkyl and aryl functionality. The polysiloxane base oils may be defined according to the formula: ##STR00001##
wherein R, and R′ are independently selected, such that R is an alkyl group having between 1-3 carbon atoms; R′ is an alkyl or aryl group having between 6 to 20 carbon atoms; and m and n are integers, such that 25<(m+n)<500 and the ratio of m/(m+n) is greater than 0.05 and less than 1.00.

A composition treating a metal surface, especially a metalworking fluid, includes the reaction product of at least one amine-functionalized organosilane and at least one organophosphate and/or at least one oligomer or polymer of the reaction product, wherein the molar ratio of the amino group/s of the at least one amine-functionalized and of the at least one organophosphate is 1.0:0.4 to 1.0:1.2, and wherein the at least one amine-functionalized organosilane is linked to the at least one organophosphate by at least one phosphoric acid/amine salt bond. Also described herein is method for producing such a composition, the use of the composition, and a method for treating a metal surface.

A lubricating oil composition for automotive transmissions is disclosed. It offers an automotive transmission (especially a fuel-saving type) which satisfies all requirements as regards the properties of resistance to churning, maintenance of the oil film and low-temperature viscosity. It comprises a GTL low viscosity base oil and a Group 1 high viscosity base oil.

An ionic liquid composition having the following generic structural formula: ##STR00001##
wherein Z is N or P, and R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently selected from hydrogen atom and hydrocarbon groups having one to four carbon atoms with optional interconnection to form a cyclic group that includes Z, and wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are all hydrocarbon groups when Z is P, and X.sup.− is a phosphorus-containing or carboxylate anion, particularly an organophosphate, organophosphonate, or organophosphinate anion, or a thio-substituted analog thereof containing hydrocarbon groups with at least three carbon atoms. Also described are lubricant compositions comprising the above ionic liquid and a base lubricant, wherein the ionic liquid is dissolved in the base lubricant. Further described are methods for applying the ionic liquid or lubricant composition onto a mechanical device for which lubrication is beneficial, with resulting improvement in friction reduction, wear rate, and/or corrosion inhibition.

The disclosed technology relates to a lubricant composition for automotive or industrial gears, as well as axles and bearings, the lubricant composition containing an oil of lubricating viscosity and a metal alkylthiophosphate compound, such as zinc dialkyldithiophosphate, as well as a method of obtaining extreme pressure performance in automotive or industrial gears, axles and bearings at lower sulfur content than is typical, by lubricating such automotive or industrial gears, axles and bearings with a lubricant composition containing a metal alkylthiophosphate compound, such as zinc dialkyldithiophosphate.

A lubricant composition includes a base lubricant and a plurality of lubricant additive molecules functioning as precursor molecules to induce tribopolymerization and forming in situ protective tribofilm with desirable robustness and low shear resistance. Each lubricant additive molecule includes one or more surface-active groups attractable to target surface, and a carbon containing component operable connected to the one or more surface active groups. The carbon containing component comprise a carbon ring structure having a high ring strain that is metastable and activatable with a ring-opening reaction. A less stable carbon ring structure is more readily activated to the intermediate state, preferable to form more active fragments. Increasing the adsorption strength further is beneficial to prolonging the residence time of additive molecules on the target surface, thereby facilitating the dissociation of molecules and subsequent polymerization.

A lubricant made from vegetable oil that can form a friction film when used. The lubricant has 86-99 wt % of vegetable oil that contains double bonds and bis-allylic protons, 10-0.5 wt % trans FAT, 3.6-0.3 wt % surfactant, and 0.4-0.2 wt % antioxidant. Additionally, the weight percentages of surfactant are 3.6˜0.3 wt %, and the weight percentages of antioxidant are 0.4˜0.2 wt %.

There is provided a lubricating oil composition which is excellent in the wear resistance and the oil film retention even when the viscosity of the composition is lowered. The lubricating oil composition comprises: a base oil (A); an imide compound (B); a calcium-based detergent (C); a polymer component (D); and a zinc dithiophosphate (E), wherein the imide compound (B) comprises at least one non-boron-modified succinic acid imide compound (Bx) selected from a succinic acid monoimide (B1x) represented by general formula (b-1) and a succinic acid bisimide (B2x) represented by general formula (b-2), and wherein the polymer compound (D) has a mass average molecular weight (Mw) of not less than 10,000 and not more than 50,000, and comprises at least one selected from an olefin polymer (D1) and a polymethacrylate (D2).