The invention relates to lubricating greases based on alkali metal soaps and/or earth-alkali metal soaps and metal complex soaps based on (R)-10-hydroxyoctadecanoic acid and to the use thereof.

Provided is grease capable of suppressing a decrease in a function as a lubricant even when used in a device installed in a refrigerant circuit in which a refrigerant containing a chlorine atom and an olefin bond in a molecule flows, and a refrigeration cycle apparatus using the grease as a lubricant. Grease that is used in a device installed in a refrigerant circuit in which a refrigerant containing a chlorine atom and an olefin bond in a molecule flows contains fluorine as a component. In a chiller apparatus, the grease is used as a lubricant for at least one of a first radial touchdown bearing and a second radial touchdown bearing of a compressor, a drive portion of an inlet guide vane of the compressor, and a drive portion of an expansion valve.

A lubricant composition for a resin-resin sliding portion or a resin-metal sliding portion that contains a base oil containing a perfluoropolyether oil including a side chain, and a polytetrafluoroethylene having a primary particle diameter of 1 μm or larger and a melamine cyanurate as thickeners.

Disclosed is food-grade lubricating grease and a method for preparing the same, belonging to the technical field of lubricating grease. The food-grade lubricating grease is prepared from the following components in percentage by mass: 75% to 85% of food-grade white oil, 6% to 16% of stearic acid, 2.0% to 3.0% of benzoic acid, 4.7% to 8.7% of aluminum isopropoxide, 1.0% to 1.5% of water and 1.0% to 7.0% of nano-PTFE, and has good extreme-pressure, abrasion-resistant and friction-reduction properties, a last non-seizure load (P.sub.B) reaching 411.6 N, a sintering load (P.sub.D) reaching 1,960 N, and a friction coefficient reduced by 18.5%. The lubricating grease can be used for a food production industry and in household food appliances, the service life of a device and the service life of the food-grade lubricating grease are effectively prolonged, and meanwhile, food security is guaranteed to a certain degree.

A rolling bearing is filled with a grease composition that contains a fluorine-based grease including a fluorine-based base oil and a fluorine-based thickener, a non-fluorine-based grease including a non-fluorine-based base oil and a non-fluorine-based thickener, and an additive serving as a dispersant. The non-fluorine-based thickener includes at least one of aliphatic-aromatic urea, alicyclic-aliphatic urea and aliphatic urea. The dispersant includes at least one of polycarboxylic acid metal salt, fluorine-containing group/lipophilic group-containing oligomer, fluorinated ether diamide, and organic acid metal salt.

The present invention provides a grease composition or a lubricating oil composition which is capable of effectively preventing hydrogen brittleness-caused peeling from occurring on a rolling surface of a rolling bearing, is excellent in durability in a high temperature and speed operation, and can be used for a long time. A grease-packed bearing (1) has an inner ring (2), an outer ring (3), and a plurality of rolling elements (4). A sealing member (6) for sealing a grease composition (7) is provided at openings (8a) and (8b) disposed at both axial ends of the inner ring (2) and the outer ring (3). The grease composition (7) includes a base grease composed of a base oil and a thickener and an additive added to the base grease. The additive contains at least one compound selected from among plant-derived polyphenolic compounds and compounds formed by decomposition thereof. The above-described compounds include tannin, gallic acid, ellagic acid, chlorogenic acid, caffeic acid, curcumin, quercetin, and quinic acid.

The invention relates to a food-compatible high-temperature lubricant, more particularly a high-temperature oil and a high-temperature grease, comprising the following components: a) at least one oil selected from a trimellitic ester or a mixture of different trimellitic esters, alkylaromatics, preferably an aliphatically substituted naphthalene, or estolides; b) a hydrogenated or fully hydrogenated polyisobutylene or a mixture of hydrogenated or fully hydrogenated polyisobutylene; and c) additives individually or in combination.

In the case of the high-temperature grease, a thickener is added.

A lubrication method comprising applying to a surface to be lubricated a polymer comprising a partially or fully fluorinated, straight or branched, polyoxyalkylene chain (chain R.sub.f) having two chain ends, wherein one or both chain end(s) bear(s) a hydroxy- or alkoxy-terminated polyoxyalkylene chain free from fluorine atoms (chain R.sub.a), said chain comprising from 4 to 50 fluorine-free oxyalkylene units, said units being the same or different from one another and being selected from —CH.sub.2CH.sub.2O— and —CH.sub.2CH(J)O—, wherein J is independently straight or branched alkyl or aryl, with the proviso that, if both chain ends bear a hydroxy-terminated chain Ra comprising only —CH.sub.2CH.sub.2O— units, chain Rf does not consist only of —CF.sub.2CF.sub.2O-units. Lubricant compositions containing the polymer and methods for preparing the polymer are also herein disclosed.

A lubrication structure for a shock absorber of vehicle has a protecting pipe and a self-lubricating layer. The protecting pipe is a non-circular metal tube and has an elongated slit. The self-lubricating layer is an engineering plastic layer, is deposited in the protecting pipe and has a shaft hole. When the lubrication structure is deposited between an outer tube and an inner tube of a shock absorber of vehicle, the protecting pipe engages in the outer tube to prevent the self-lubricating layer from contacting the outer tube directly. The self-lubricating layer with small friction coefficient is mounted around the inner shaft to enable the inner shaft to move smoothly relative to the outer tube. The lubrication structure has characteristics of low cost, small volume, and small tolerance, and the life and the practicality of the lubrication structure can be improved.

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.