Disclosed herein are embodiments of a method of making a lubricant composition for lapping a ceramic material. The method includes mixing a base lubricant component and a powdered wax composition component to form the lubricant composition. The powdered wax composition component includes a powdered wax dispersion or a powdered wax emulsion. The amount of powdered wax composition component mixed with the base lubricant component is from 0.01 to 10 percent by weight of the lubricant composition. Also disclosed herein are embodiments of related lubricant compositions and/or methods of using the lubricant to lap a ceramic substrate (e.g., one or more bars of sliders).

Provided is a compound which has heat resistance and decomposition resistance and with which a monomolecular film having a reduced thickness can be obtained. A fluoropolyether compound in accordance with an aspect of the present invention is represented by R.sup.1—C.sub.6H.sub.4O—CH.sub.2CH(OH)CH.sub.2OCH.sub.2—R.sup.2—CH.sub.2—O—CH.sub.2CH(OH)CH.sub.2—OC.sub.6H.sub.4—R.sup.1 where R.sup.1 is a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, an amino group, or an amide group, R.sup.2 is —CF.sub.2O(CF.sub.2CF.sub.2O).sub.xCF.sub.2—, and x is a real number of 1 to 35.

Embodiments disclosed herein generally relate to magnetic recording systems having a spindle motor and, more particularly, to an optimized lubricant for bearings within the spindle motor. A lubricant used in a fluid dynamic bearing motor has an antioxidant additive and a charge control agent dissolved in a diester base oil. The charge control agent is chemically attached to the same diacid reactant used in the diester lubricant base oil, and is prepared through an esterification reaction. The charge control agent is then dissolved in the lubricant base oil. The charge control agent is soluble in the lubricant, and is resistant to free radical oxidation. The charge control agent effectively controls the charge of the lubricant by creating electron donor/acceptor sites in the lubricant, facilitating an independent electronic pathway through the lubricant.

Provided is a compound with which a lubricant having excellent adhesion to a magnetic disk, particularly to a protective layer can be provided. A perfluoropolyether compound in accordance with one aspect of this invention has a structure in which two perfluoropolyethers are bonded to each other through an aliphatic ether, the aliphatic ether including a carbon atom to which a primary alcohol is bonded.

The present invention aims to provide solid particles with improved lubrication, a solid lubricant including the solid particles, and a metal member including, on the surface thereof, the solid particles or the solid lubricant. The solid particles of the present invention include base particles and carbon fluoride particles attached to surfaces of the base particles.

In one embodiment, a method for forming a substantially monodisperse lubricant includes: providing a plurality of perfluoropolyether (PFPE) precursors, each PFPE precursor including two end segments and a PFPE backbone disposed therebetween; protecting one of the end segments of each PFPE precursor with one or more protecting agents to form a plurality of mono-protected PFPE precursors, each mono-protected PFPE precursor including a protected end segment and an unprotected end segment; and coupling the unprotected end segment of each of the mono-protected PFPE precursors to the unprotected end segment of another of the mono-protected PFPE precursors via a coupling agent to form multidentate PFPE structures. In another embodiment, a substantially monodisperse lubricant includes a plurality of multidentate perfluoropolyether (PFPE) structures, each multidentate PFPE structure including at least two end segments and a middle segment therebetween, wherein the multidentate PFPE structures have a molecular weight that is substantially the same.

The present invention relates to a phosphazene compound [compound (L)] comprising a cyclophosphazene central core wherein each phosphorus atom of said core bears a substituent independently selected from: a) a chain (A), said chain (A) comprising a (per)fluoropolyether chain [chain (R.sub.f)], one or more aromatic or heteroaromatic moieties [moiety/ies (Ar.sup.m)] and, optionally, one or more hydroxy groups and b) a chain (B), said chain (B) comprising a (per)fluoropolyether chain [chain (R.sub.f)] and one or more hydroxy groups with the proviso that at least one phosphorous atom of the central core is substituted with chain (A) and to mixtures of compounds (L). The invention further relates to methods for preparing compounds (L), to lubricant compositions comprising compounds (L) and to methods for lubricating magnetic recording media comprising applying a compound (L) or a lubricant compositions containing them to the surface of said medium.

Disclosed is a fluoropolyether compound comprising a C.sub.4-10 aliphatic hydrocarbon chain present in the middle of the fluoropolyether compound and at least two perfluoropolyethers.

This fluorine-containing ether compound is a fluorine-containing ether compound represented by formula (1).

R.sup.1—X—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4  (1)

(In formula (1), R.sup.1 is an alkenyloxy group of 2 to 8 carbon atoms or an alkynyloxy group of 3 to 8 carbon atoms. R.sup.2 is represented by formula (2) shown below. In formula (2), a represents an integer of 1 to 3. X is represented by formula (3) shown below. In formula (3), b represents an integer of 1 to 5, Y is a divalent linking group that is bonded to a carbon atom in formula (2), and R represents an alkyl group of 1 to 6 carbon atoms or H. R.sup.3 represents a perfluoropolyether chain. R.sup.4 represents a terminal group containing two or three polar groups, wherein each polar group is bonded to a different carbon atom, and the carbon atoms to which the polar groups are bonded are bonded to each other via a linking group containing a carbon atom to which a polar group is not bonded.)

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A magnetic recording medium that can exhibit good traveling performance during use is provided. This magnetic recording medium is a tape-shaped magnetic recording medium, and includes a substrate including a polyester as a main component, a base layer disposed on the substrate, and a magnetic layer disposed on the base layer. The kurtosis of the surface of the magnetic layer is 3.0 or more. The base layer and the magnetic layer each include a lubricant including a fatty acid and a fatty acid ester. In the lubricant, a ratio of the content of the fatty acid to the content of the fatty acid ester is less than 0.6.