Provided is a lubricant composition including a bicyclic liquid crystal of formula (1), and a tricyclic liquid crystal compound of formula (2), and having a mixing mass ratio of the bicyclic liquid crystal compound and tricyclic liquid crystal compound of 95:5 to 15:85. The composition is suitable for use in a clean environment, under a high vacuum, under high temperature and a bearing. ##STR00001##
R.sup.1 and R.sup.2 are the same or different from each other, and each is —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR ##STR00002##
R.sup.11 and R.sup.21 are the same or different from each other, and each is —OR. R.sup.12, R.sup.13, R.sup.22 and R.sup.23 are the same or different from each other, and each is hydrogen or —OR. R is a linear or branched C.sub.nH.sub.2n+1, 1≤n≤20 and R′ is methyl or ethyl.

The present invention relates to a magnetic recording medium in which a lubricant layer contains a compound A represented by general formula (1) and a compound B represented by general formula (2), satisfying (A/B)=0.2 to 3.0, and has an average thickness of 0.8 nm to 2 nm. R.sup.1—C.sub.6H.sub.4OCH.sub.2CH(OH)CH.sub.2OCH.sub.2—R.sup.2—CH.sub.2OCH.sub.2CH(OH)CH.sub.2OH . . . (1) (R.sup.1 is an alkoxy group having 1 to 4 carbon atoms. R.sup.2 is —CF.sub.2O(CF.sub.2CF.sub.2O).sub.x(CF.sub.2O).sub.yCF.sub.2— (x, y=0 to 15), —CF.sub.2CF.sub.2O(CF.sub.2CF.sub.2CF.sub.2O).sub.zCF.sub.2CF.sub.2— (z=1 to 15), —CF.sub.2CF.sub.2CF.sub.2O(CF.sub.2CF.sub.2CF.sub.2CF.sub.2).sub.nCF.sub.2CF.sub.2CF.sub.2— (n=0 to 4). HOCH.sub.2CF.sub.2CF.sub.2O(CF.sub.2CF.sub.2CF.sub.2O).sub.mCF.sub.2CF.sub.2CH.sub.2OCH.sub.2CH(OH)CH.sub.2OH . . . (2) (m is an integer).

A fluorine-containing ether compound represented by R.sup.1—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4—R.sup.5 is provided. (R.sup.3 is a perfluoropolyether chain; R.sup.1 and R.sup.5 are each independently any one of an alkyl group that may have a substituent, an organic group having at least one double bond or at least one triple bond, and a hydrogen atom; and —R.sup.2—CH.sub.2—R.sup.3 is represented by Formula (2), and R.sup.3—CH.sub.2—R.sup.4— is represented by Formula (3))
-[A]-[B]—O—CH.sub.2—R.sup.3  (2)
R.sup.3—CH.sub.2—O—[C]-[D]-  (3)
([A] is represented by Formula (4), [B] is represented by Formula (5), [C] is represented by Formula (6), [D] is represented by Formula (7), and in the formula, a and b are integers of 0 to 2, c is an integer of 2 to 5, d and f are integers of 0 to 2, and e is an integer of 2 to 5, and at least one of b and d in the formula is 1 or more) ##STR00001##

The invention provides a fullerene compound; a lubricant that is for a magnetic recording medium and that contains the fullerene compound; and a magnetic recording medium. The fullerene compound is an ionic liquid that is represented by general formula (1) and is formed from a Bronsted acid (H.sub.n1X) and a Bronsted base ([R.sub.2R.sub.3)N—].sub.m1—R.sub.1); wherein one of the Brønsted acid and the Broønsted base contains a group having a fullerene; and the other contains a perfluoroalkyl chain. ##STR00001##

Provided herein is a lubricant including a compound of Formula I
L-(CF.sub.2CF.sub.2O).sub.n—CF.sub.2CH.sub.2O—N—OCH.sub.2CF.sub.2O—(CF.sub.2CF.sub.2O).sub.m-M  (Formula I)
wherein L is selected from the group consisting of ##STR00001## M is selected from the group consisting of ##STR00002##
wherein each instance of R.sup.1, R.sup.2, and R.sup.3 is independently selected from the group consisting of hydroxyl, alkoxyl, carbocycyl, phenyl, heterocycyl, piperonyl, carboxyl, alkylamido, acetamido, carbamoyl, N-alkylcarbamoyl, N,N-dialkylcarbamoyl, 2,3-dihydroxy-1-propoxyl, acryloyl, alkacryloyl, methacryloyl, a substituent of methyl methacrylate, and a substituent of glycidyl ether; and
wherein n≧1, m≧1, and n and m are the same or different.

A lubricant including a plurality of segments including a divalent center segment and two sidechain segments, each including a perfluoroalkyl ether moieties is provided in which a dewetting thickness of the lubricant may be determined based in-part on a segment weight average molecular weight of the segments. A magnetic recording medium and a magnetic data storage system including the lubricant are also provided.

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 fluorine-containing ether compound is represented by the following formula (1): R.sup.1—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4. In the formula (1), R.sup.1 is represented by the following formula (2), R.sup.2 is represented by the following formula (3), R.sup.3 is a perfluoropolyether chain, and R.sup.4 is an organic end group different from R.sup.1—R.sup.2— and contains 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 one another via a linking group containing a carbon atom to which the polar group is not bonded. In the formula (2), R.sup.5 is an alkoxy group selected from the group consisting of a methoxy, an ethoxy and a propoxy group. In the formula (3), w is 2 or 3.

##STR00001##

The fluorine-containing ether compound is represented by the following formula (1): R.sup.1-R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4. In the formula (1), R.sup.1 is represented by the following formula (2), R.sup.2 is represented by the following formula (3), R.sup.3 is a perfluoropolyether chain, and R.sup.4 is an organic end group different from R.sup.1-R.sup.2- and contains 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 one another via a linking group containing a carbon atom to which the polar group is not bonded. In the formula (2), r is 1 to 3. In the formula (3), w is 2 or 3.

##STR00001##

A fluorine-containing ether compound represented by Formula (1) is provided.
R.sup.1—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4—R.sup.5   (1)
(In Formula (1), R.sup.1 and R.sup.5 each represents a group having a heterocyclic ring and may be the same as or different from each other, R.sup.2 and R.sup.4 each represents a divalent linking group having a polar group and play be the same as or different from each other, and R.sup.3 represents a perfluoropolyether chain.)