A grease composition includes a base oil, a thickener and at least one kind of an antioxidant selected from an amine-based antioxidant and a phenol-based antioxidant expressed by the following respective general formulas (1) and 2: ##STR00001##
The base oil contains a poly--olefin and a mineral oil. A mass ratio of poly--olefin/mineral oil is 1.25 to 9.

Disclosed is an internal combustion engine lubricating oil composition which comprises (a) a major amount of an oil of lubricating viscosity; (b) a dispersant-type olefin copolymer VI improver; and (c) a secondary hydrocarbylamine compound, a tertiary hydrocarbylamine compound, or combinations thereof. A method for reducing cam wear using same is also disclosed.

Through a lubricating oil additive including an amide compound represented by the following general formula (1) and a lubricating oil composition using the same, a lubricating oil additive and a lubricating oil composition exhibiting not only a high intermetal friction coefficient but also excellent intermetal friction-coefficient/slipping-velocity characteristics are provided.

R.sup.aCO(NH-L.sup.1).sub.n-NR.sup.bR.sup.c (1)

In the formula, R.sup.a is a straight-chain alkyl group having 8 to 22 carbon atoms or a branched-chain alkyl group having 8 to 22 carbon atoms, or a straight-chain alkenyl group having 8 to 22 carbon atoms or a branched-chain alkenyl group having 8 to 22 carbon atoms; L.sup.1 is an alkylene group having 1 to 6 carbon atoms; n is an integer of 1 to 4; and NR.sup.bR.sup.c is a primary amino group or a piperazyl group.

A lubricant composition comprises as a lubricant base, an oil soluble polyalkylene glycol suitable for use as a lubricant in an industrial oil, grease or metal working fluid; and an additive comprising (1) alkylated phenyl--naphthylamine; and (2) 2,2,4-trialkyl-1,2-dihydroquinoline.

A lubricant composition including an acyclic amine compound. A method of lubricating a system including a fluoro-polymer seal with the lubricant composition is also provided. An additive concentrate for a lubricant composition is also provided. The acyclic amine compound is useful for adjusting the total base number of a lubricant composition. The lubricant composition is compatible with fluoropolymer seals.

Described herein is an ashless oil additive, comprising at least one diazabicyclo or triazabicyclo compound. Also described is a composition comprising an engine oil mixed with an oil additive, wherein the oil additive comprises at least one diazabicyclo or triazabicyclo compound. Further described is a method for boosting the total base number (TBN) of an engine oil composition, comprising adding an oil additive to said engine oil composition, wherein the oil additive comprises at least one diazabicyclo or triazabicyclo compound.

The present invention provides a lubricant composition which can be used as a lubricant for a rolling component, the composition capable of maintaining enhanced lubrication performance over a long period of time even under high temperature conditions such as temperatures of 180 C. or higher, and a rolling bearing including the lubricant composition sealed therein. A lubricant composition-sealed bearing 1 includes a lubricant composition 7 that is sealed in the peripheries of the rolling bodies 4. The lubricant composition 7 contains a base oil and an antioxidant. The base oil is an oil mixture of an alkyl diphenyl ether oil and at least one oil selected from a poly--olefin oil and an ester oil, and contains the alkyl diphenyl ether oil in an amount of 50% or more by weight of the total base oil. The antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline or a polymer thereof, and is contained in an amount of 0.1% to 10% by weight of the total lubricant composition.

A lubricant including an ionic liquid, which includes a conjugate acid (B.sup.+) and a conjugate base (X.sup.), and is protic, wherein the ionic liquid is represented by the following general formula (1):

##STR00001##

where R.sup.1 and R.sup.2 each represent a hydrogen atom or R.sup.1 and R.sup.2 form a benzene ring together with carbon atoms to which R.sup.1 and R.sup.2 are bonded, and R.sup.3 represents a straight-chain hydrocarbon group having 10 or more carbon atoms in the general formula (1).

A lubricating oil composition for refrigerating machines contains a base oil and an additive in a form of a coumarin compound. 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.

The present invention provides a lubricating oil composition comprising: (a) a major amount of a lubricating oil, (a) a diarylamine antioxidant, and (b) an amidine compound of Formula (I),

##STR00001## wherein R.sub.1 is hydrogen, an alkyl or an aromatic group containing 1-30 carbon atoms; x is from 1 to 5; Y is an optional linking alkyl group; Z is carbon or nitrogen; and R.sub.2 is hydrogen or alkyl groups containing 1-30 carbon atoms.

Also provided is a method for lubricating an engine comprising lubricating the engine with said lubricating oil composition.