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.

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.

A deposition composition includes a solvent comprising a hydrofluorothioether compound represented by the following general formula (I): RfSRh where Rf is a fluorinated or perfluorinated group having 2-9 carbon atoms and optionally includes one or more catenated heteroatoms or chlorine atoms, and Rh is a non-fluorinated hydrocarbon group having 1-3 carbon atoms. The deposition composition further includes a coating material that is soluble or dispersible in said solvent.

A fluorine-containing ether compound represented by the formula (1) is provided. The fluorine-containing ether compound is represented by the following formula (1). R.sup.1R.sup.2CH.sub.2R.sup.3CH.sub.2R.sup.4 (1) (R.sup.3 is a perfluoropolyether chain; R.sup.1 is the formula (2), a in the formula (2) is an integer of 2 or 3, R.sup.5 and R.sup.6 are the same or different substituents. R.sup.5 and R.sup.6 may form a ring structure together with a nitrogen atom; R.sup.2 is the formula (3), b in the formula (3) is an integer of 1 to 3; R.sup.4 is a terminal group having two or three polar groups, in which individual polar groups bond to different carbon atoms and the carbon atoms to which the polar groups bond are bonded to each other through a linking group having a carbon atom to which the polar groups do not bond.) ##STR00001##

Provided is a lubricant composition including a bicyclic liquid crystal of formula (1), tricyclic liquid crystal compounds of formula (2), and formula (3). 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 a group OR. ##STR00003##
R.sup.31 and R.sup.41 are the same or different from each other, and each is OCH.sub.2CH.sub.2CH(R)CH.sub.2CH.sub.2OR. R.sup.32, R.sup.33, R.sup.42, and R.sup.43 are the same or different from each other, and each is hydrogen or OCH.sub.2CH.sub.2CH(R)CH.sub.2CH.sub.2OR. R is a linear or branched C.sub.nH.sub.2n+1, 1?n?20, and R is methyl or ethyl.

A fluorine-containing ether compound represented by Formula (1) is provided.
R.sup.1OR.sup.2CH.sub.2R.sup.3CH.sub.2R.sup.4R.sup.5(1)
(in the formula, R.sup.3 is a perfluoropolyether chain; R.sup.1 is an alkenyl group having 2 to 8 carbon atoms or an alkynyl group having 3 to 8 carbon atoms; R.sup.2 and R.sup.4 are each independently a divalent linking group having one or more hydroxyl groups; and R.sup.5 is a group represented by Formula (2) shown below.)
O(CH.sub.2).sub.gNR.sup.6R.sup.7(2)
(in the formula, g is an integer of 2 or 3; R.sup.6 and R.sup.7 are the same or different saturated aliphatic groups; and R.sup.6 and R.sup.7 may form a ring structure together with a nitrogen atom.)

Lubricants with epoxide-based linkages for Heat Assisted Magnetic Recording (HAMR) are provided. Epoxide chemistry produces one such lubricant for magnetic media according to general formula (Ia):

##STR00001##

where D.sub.n is (CF.sub.2CF.sub.2CF.sub.2O).sub.n, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 independently comprise single or branched non-fluorinated or fluorinated C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.10 alkoxy, benzene, naphthalene, anthracene, phenanthrene, dibenz[a,h]anthracene, pyrene or benzopyrene, with n being from 2 to 50.

The present invention provides a fluorine-containing ether compound represented by the following formula.
R.sup.1CH.sub.2R.sup.2CH.sub.2R.sup.3CH.sub.2R.sup.4CH.sub.2R.sup.5CH.sub.2R.sup.6CH.sub.2R.sup.7
(In Formula (1), R.sup.2, R.sup.4, and R.sup.6 are perfluoropolyether chains, R.sup.3 is Formula (2), R.sup.5 is Formula (3), and R.sup.1 and R.sup.7 are each independently a terminal group having two or three polar groups, in which individual polar groups are bound to different carbon atoms and the carbon atoms to which the polar groups are bound are bound to each other via a linking group containing a carbon atom to which no polar group is bound). ##STR00001##

A lubricant provides enhanced performance at high temperatures, along with a higher evaporation temperature, where the main-chain includes a moiety with a rotational energy barrier that is higher than CF.sub.2. The lubricant has the general Formula (I): ##STR00001##
wherein Rc is a multivalent central group, Rb is a main chain group having a constituent with a higher rotational energy threshold than CF.sub.2, Re is an end group having at least one anchoring functional group, m is from 2 to 50, and n is from 2 to 8. The constituent with a higher rotational energy threshold than CF.sub.2, may be a substituted or non-substituted aromatic group.