Acrylate-olefin copolymers and a method for the preparation of these copolymers are provided. Lubricant compositions can contain the aforementioned copolymers. The copolymers are useful as a lubricant additive or a synthetic base fluid in a lubricating oil composition, preferably in a gear oil composition, a transmission oil composition, a hydraulic oil composition, an engine oil composition, a marine oil composition, an industrial lubricating oil composition or in grease.

A lithium-based grease and the preparation method thereof are provided. The raw materials for preparing the lithium-based grease include in parts by weight: 75-88 parts of base oil, 0.5-2.5 parts of antiwear agent, 0.1-1.5 parts of antirust agent, 0.1-1.5 parts of antioxidant, 5-25 parts of lubricant, 5-15 parts of thickening agent, and 0.6-2.0 parts of saponifying agent. The raw materials also include hydroxyl compound-containing modified graphene containing quaternary ammonium salt or aromatic ring. The grease has good colloid stability and mechanical stability, can greatly improve the antiwear property. More than that, the grease has excellent oxidation resistance, and can significantly shorten the reaction time of the saponification, reduce the reaction temperature of the saponification.

A grease composition for resin lubrication, the grease composition to be applied to a sliding surface made of resin, the grease composition containing: a fluorine-based base oil (a kinematic viscosity at 40° C. of 300 mm.sup.2/s or higher) and a synthetic hydrocarbon oil as base oils; a fluorine-based thickener, and a lithium soap thickener or a lithium complex soap thickener as thickeners; and a fluorine-based surfactant and an extreme pressure additive as additives; and a resin sliding member (slide switch) having a sliding surface made of resin, the sliding surface provided by application with the grease composition.

A grease composition is intended primarily for use in constant velocity joints (CV joints), especially ball joints and/or tripod joints, which are used in the driveline of motor vehicles. The grease composition for use in constant velocity joints comprises at least one base oil, at least one thickener, zinc sulfide, as well as molybdenum disulfide and/or tungsten disulfide. Further, a constant velocity joint comprises the grease composition.

Provided is a lubricant composition including a bicyclic liquid crystal of formula (1), tricyclic liquid crystal compounds of formula (2), and formula (3). The composition is suitable for use in a clean environment, under a high vacuum, under high temperature and a bearing.

##STR00001##

R.sup.1 and R.sup.2 are the same or different from each other, and each is —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR.

##STR00002##

R.sup.11 and R.sup.21 are the same or different from each other, and each is —OR. R.sup.12, R.sup.13, R.sup.22 and R.sup.23 are the same or different from each other, and each is hydrogen or a group —OR.

##STR00003##

R.sup.31 and R.sup.41 are the same or different from each other, and each is —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR. R.sup.32, R.sup.33, R.sup.42, and R.sup.43 are the same or different from each other, and each is hydrogen or —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR. R is a linear or branched C.sub.nH.sub.2n+1, 1≤n≤20, and R′ is methyl or ethyl.

A grease composition includes a base oil, a thickener, and an additive. The base oil contains a synthetic oil. The thickener contains a compound having a urea group. The additive contains a phosphoric compound, a calcium-based compound, and a hydrocarbon-based wax. A hub unit includes the grease composition enclosed therein.

A grease composition is intended primarily for use in constant velocity joins (CV joints), especially ball joints and/or tripod joints, which are used in the drivelines of motor vehicles. The grease composition for use in constant velocity joints comprises at least one base oil, and least one thickener, at least one copper sulfide in an amount of approximately 0.01 wt-% up to approximately 1.5 wt-% of the grease composition, molybdenum disulfide and/or at least one phosphor-free organic molybdenum complex in an amount of approximately 0.1 wt-% up to approximately 5.0 wt-% of the grease composition. Further, a constant velocity joint comprises the grease composition.

An aspect of the present invention relates to a lubricant composition containing at least: (A) 50 to 80 mass % of silicone oil represented by formula (1) below, and having a mass-average molecular weight of 900 to 4000, a ratio (C/Si ratio) of carbon to silicon of 3.03 or higher in the structure, and a viscosity index (VI) of 300 or higher; (B) 10 to 49 mass % of hydrocarbon-based lubricant; and (C) 1 to 10 mass % of antioxidant.

This is to provide an electrically-conductive lubricant having characteristics in combination that it shows liquid crystallinity in a wide temperature range, retains low dynamic friction coefficient, has electrical-conductivity, has almost no loss due to evaporation, decomposition and the like, has a clean appearance, and emits fluorescence, and can find deterioration or leakage immediately. This electrically-conductive lubricant comprises at least one kind of the compound (1) represented by the formula (1): ##STR00001##
12:8 wherein, R.sup.11 and R.sup.21 are the same or different from each other, and each is hydrogen or a group —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR (R is a linear or branched C.sub.nH.sub.2n+1, 4≤n≤12, and R′ is methyl or ethyl), and R.sup.12, R.sup.13, R.sup.22 and R.sup.23 are the same or different from each other, and each is a group —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR (R is a linear or branched C.sub.nH.sub.2n+1, 4≤n≤12, and R′ is methyl or ethyl)].

The invention provides a grease composition for a ball joint which has a low friction coefficient under a load from normal temperatures to high temperatures, a small difference between static friction and dynamic friction, and little change in the friction coefficient even after repeated operation. TO this end, the invention provides a grease composition for a ball joint comprising: (i) a polyisoprene rubber and/or (ii) a polyisoprene rubber viscous material; a specific aliphatic amide and/or a specific aliphatic bisamide; and a specific urea compound.