The present invention is directed to highly-concentrated compositions of salts of alkyl polyalkoxy sulphates, whereby in total at least ⅔ of all alkoxy unit of the alkyl polyalkoxy sulphates are propoxy units.

A high-molecular-weight compound having a plurality of polymer chains linked through a divalent or higher-valent linking group, in which the divalent or higher-valent linking group has a thiol group and at least one of a thioether structure and a thiourethane structure, and a ratio of an absolute weight-average molecular weight to a relative weight-average molecular weight (absolute Mw/relative Mw) of the high-molecular-weight compound is 1.25 or more; and a method for producing the same are provided.

The present invention is a lubricating agent containing a compound represented by the following formula 1:

##STR00001##

wherein R.sup.1 and R.sup.2 each represent a hydrocarbon group with 6 or more and 24 or less carbons; A.sup.10 and A.sup.2O each represent an alkyleneoxy group with 2 or more and 4 or less carbons; x1 and x2 are average numbers of added moles, and each represent a number of 0 or more and 10 or less; and M is a cationic ion.

The invention relates to a PTFE polymer-based sliding material having fillers which improve the tribological properties, wherein the fillers comprise at least one phosphate, in particular calcium phosphate, calcium pyrophosphate, magnesium phosphate, magnesium pyrophosphate, lithium phosphate, hydroxyapatite or combinations thereof, and at least one metal sulfide, wherein the fraction of the metal sulfide is >2% by volume. The invention also relates to uses of said sliding material.

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.

The present invention relates to a sulphur-containing polyester capable of being obtained by a process comprising esterification reactions between a polyol and a carboxylic acid and a thiolactic acid, or by a process comprising an esterification reaction between a partially esterified polyol and a thiolactic acid. It also concerns its use as a multiproperty additive, and compositions comprising it.

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.1—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4—R.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. ##STR00001##

A lubrication board includes a substrate; and a lubrication layer disposed on a surface of the substrate, wherein the lubrication layer comprises a polymer expressed by formula (I) below,

##STR00001##

wherein R.sub.1 is selected from a substituted or unsubstituted C.sub.2-C.sub.18 alkyl or C.sub.2-C.sub.18 aryl; R.sub.2 is selected from a substituted or unsubstituted C.sub.2-C.sub.18 alkyl or C.sub.2-C.sub.18 alkyl which is interrupted by —O—; R.sub.3 is selected from —NH— or —S—; R.sub.4 is selected from —NH.sub.2, —OH or —SH; and n, p and q are positive integers ranging from 2 to 20000.

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 lubrication board includes a substrate; and a lubrication layer disposed on a surface of the substrate, wherein the lubrication layer comprises a polymer expressed by formula (I) below, ##STR00001##
formula (I); wherein R.sub.1 is selected from a substituted or unsubstituted C.sub.2-C.sub.18 alkyl or C.sub.2-C.sub.18 aryl; R.sub.2 is selected from a substituted or unsubstituted C.sub.2-C.sub.18 alkyl or C.sub.2-C.sub.18 alkyl which is interrupted by —O—; R.sub.3 is selected from —NH— or —S—; R.sub.4 is selected from —NH.sub.2, —OH or —SH; and n, p and q are positive integers ranging from 2 to 20000.