A lubrication method including lubricating a sliding member which contains at least one selected from the group consisting of a liquid crystal polymer and polyetheretherketone by using a lubricating oil composition which contains at least one selected from the group consisting of a mineral oil and alkyl benzene as a lubricating base oil.

Provided is a fluorine-containing ether compound capable of forming a lubricant layer having excellent wear resistance even when the thickness is thin, and suitable as a material of a lubricant for a magnetic recording medium. The fluorine-containing ether compound is a compound represented by the following formula (1): R.sup.1R.sup.2CH.sub.2R.sup.3CH.sub.2R.sup.4R.sup.5; wherein R.sup.3 is a perfluoropolyether chain; R.sup.1 is a terminal group bonded to R.sup.2; R.sup.5 is a terminal group bonded to R.sup.4; R.sup.1 is an alkenyl group or an alkynyl group; R.sup.5 is a group containing a heterocyclic ring; R.sup.2 is represented by the following formula (2); R.sup.4 is represented by the following formula (3); and a in the formula (2) and b in the formula (3) are each independently an integer of 1 to 3.

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The invention relates to an anti-friction lacquer having a polymer as a resin matrix and functional fillers, the functional fillers containing mixed-phase oxides and optionally further functional fillers. The invention further relates to a sliding element having a metallic substrate layer and a coating which is applied thereon and made of at least such an anti-friction lacquer and to a method for the production thereof.

A constant velocity joint having a boot constructed from a thermoplastic polyether ester as the boot material. The boot includes a lubricating grease composition for lubricating the constant velocity joint, the lubricating grease composition comprising calcium lignin sulfonate.

A polymer having the structure (I):

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L is a linking group, R is a hydrocarbon group or a substituted-hydrocarbon group, and x is 2 or more, preferably from 2 to 100, more preferably from 2 to 50. Each {Q} is (a) an identical polymer block composed of 3 or more monomer units, or (b) contains a plurality of polymer blocks, each polymer block being composed of 3 or more monomer units, such that the moiety {Q}-L-{Q} has the structure {P.sub.n . . . P.sub.2P.sub.1}-L-{P.sub.1P.sub.2 . . . P.sub.n} where each P.sub.n is an individual polymer block, the number of polymer blocks n in each {Q} being the same; wherein for each value of n the polymer blocks are identical; and wherein n is an integer of 2 or more, preferably from 2 to 100, more preferably from 2 to 50.

The present invention provides an electrorheological fluid, which includes a dielectric particle, a conductor particle and insulating oil, and the dielectric particle is evenly dispersed in the insulating oil; wherein the conductor particle is evenly dispersed in the insulating oil or inlaid in an interior and on a surface of the dielectric particle. The electrorheological fluid has the advantages of high shear stress, long service life, good temperature stability and small leakage current.

A viscosity index improver comprising a polymer which has a high viscosity index and good shear stability and which exhibits sufficient solubility in a lubricating base oil, a process for producing the same, and a lubricating oil composition containing the viscosity index improver are provided, wherein the viscosity index improver comprising a polymer satisfying the following (1) to (4): (1) weight-average molecular weight (Mw) of 200,000 or more and 600,000 or less; (2) number-average molecular weight (Mn) of 90,000 or more; (3) molecular weight distribution (Mw/Mn) of 4.0 or less; and (4) branching degree of 1.0 or more.

A viscosity index improver comprising a polymer which has a high viscosity index and good shear stability and which exhibits sufficient solubility in a lubricating base oil, a process for producing the same, and a lubricating oil composition containing the viscosity index improver are provided, wherein the viscosity index improver comprising a polymer satisfying the following (1) to (4): (1) weight-average molecular weight (Mw) of 200,000 or more and 600,000 or less; (2) number-average molecular weight (Mn) of 90,000 or more; (3) molecular weight distribution (Mw/Mn) of 4.0 or less; and (4) branching degree of 1.0 or more.

To provide a lubricating oil composition that has good detergency irrespective of the small sulfated ash content thereof, and has a good friction reducing capability even after the deterioration thereof. The lubricating oil composition contains a base oil (A), a non-metal-containing sulfur antioxidant (B), and a hindered amine antioxidant (C) having one piperidine-derived skeleton in a molecule, and has a content of the non-metal-containing sulfur antioxidant (B) as converted in terms of sulfur atom of 800 ppm by mass or more based on the total amount of the lubricating oil composition, a content of the hindered amine antioxidant (C) as converted in terms of nitrogen atom of 100 ppm by mass or more and 400 ppm by mass or less based on the total amount of the lubricating oil composition, a sulfated ash content of 0.70% by mass or less, and a total base number of 4.0 mgKOH/g or more.

A composition that includes one or more compounds represented by the formula

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wherein R1 and R2 are same or different and are the residue of an alkyl group having more than 10 carbon atoms wherein the composition has a viscosity (Kv.sub.100) from 2 to 300 at 100 C. as determined by ASTM D-445, and a viscosity index (VI) from 100 to 300 as determined by ASTM D-2270. The disclosure also relates to a process for producing the composition, a lubricating oil base stock and lubricating oil containing the composition, and a method for improving oxidative stability of a lubricating oil by using as the lubricating oil a formulated oil containing the composition.