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.

A lubricant, which includes an ionic liquid including a conjugate base and a conjugate acid, wherein the conjugate acid is represented by General Formula (A) below, and wherein a pKa of an acid that is a source of the conjugate base in acetonitrile is 10 or less,

##STR00001##

where, in General Formula (A), R.sub.1, R.sub.2, and R.sub.3 are each independently a group including a hydrocarbon group, with the proviso that at least one of the hydrocarbon groups in R.sub.1, R.sub.2, and R.sub.3 is a straight-chain hydrocarbon group having 6 or greater carbon atoms.

The present invention relates to the use of a chemical composition to modify the physical properties (viscosity and interfacial tension) of heavy and extra-heavy crude oils, to increase their mobility. The chemical composition comprises or consists of a combination of systems based on ionic and non-ionic liquids, which may be pure or modified, mixed in an aqueous or organic medium as a dispersing agent, depending on the nature of the crude to be treated, together with a surfactant. The composition is mixed with the crude oil at a temperature between 5 and 100° C., at pressures from 1 atm (14.7 psi) up to about 680.2 atm (10,000 psi). The composition can be mixed with heavy crude oils, at the point of extraction from the well in the field, during the transport of crude oil in pipelines, or in the well discharge pipelines.

Anti-wear and/or friction reducing formulations that include a mixture of at least one first ionic liquid and at least one ashless antiwear compound. The ashless antiwear compound can be a second ionic liquid or an ashless thiophosphate compound. The formulation desirably provides synergistic anti-wear and/or friction reducing properties. The first IL can be a monocationic ionic liquid or a dicationic ionic liquid. The second IL is a dicationic ionic liquid. The ashless thiophosphate is desirably a thiophosphate, such as a fluorothiophosphate (FTP), an alkylphosphorofluoridothiolate, or an alkylthioperoxydithiophosphate. Antiwear and/or friction reduction formulations comprising the above mixtures diluted up to 25% by weight in a 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.

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.

Use of a guanidinium-based ionic liquid as detergent in a lubricant composition, notably for lubricating marine engines. A lubricant composition including a guanidinium-based ionic liquid.

This method for producing a lubricating oil composition includes: a step of dissolving fullerenes in a base oil mainly composed of a multiply alkylated cyclopentane oil or an ionic liquid containing an imide as a negative ion to obtain a fullerene solution; and a step of producing fullerenes adduct by subjecting the above-described fullerene solution to a heat treatment in a non-oxidizing atmosphere.

A composite material comprising a plurality of polymer chains fixed to a base and swelled with a mixture which contains a salt and a hydrogen bond-donating compound and has a melting point maintained at 100° C. or less.

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.