Provided is a lubricant solution capable of being applied to a magnetic disk without use of a fluorine solvent. A lubricant solution in accordance with an aspect of the present invention includes: water; and a perfluoropolyether compound that satisfies Expression (I) below:

N.sub.OH/(Mn/1500)≥2  (1), where N.sub.OH represents the number of hydroxyl groups per molecule of the perfluoropolyether compound and Mn represents a number average molecular weight of the perfluoropolyether compound.

Provided is a lubricant solution capable of being applied to a magnetic disk without use of a fluorine solvent. A lubricant solution in accordance with an aspect of the present invention includes: water; and a perfluoropolyether compound that satisfies Expression (I) below:

N.sub.OH/(Mn/1500)≥2  (1), where N.sub.OH represents the number of hydroxyl groups per molecule of the perfluoropolyether compound and Mn represents a number average molecular weight of the perfluoropolyether compound.

A fluorine-containing ether compound represented by the following formula (1) is provided.

R.sup.2—CH.sub.2—R.sup.1—CH.sub.2OCH.sub.2CH(OH)—(CH.sub.2).sub.n—CH(OH)CH.sub.2OCH.sub.2—R.sup.1—CH.sub.2—R.sup.2  (1)

(in the formula (1), n is an integer of 2 to 6, R.sup.1 is a perfluoropolyether chain, R.sup.2 is —OCH.sub.2CH(OH)CH.sub.2O(CH.sub.2).sub.mOH (m in the formula is an integer of 2 to 4)).

A fluorine-containing ether compound represented by the following formula (1) is provided.

R.sup.2—CH.sub.2—R.sup.1—CH.sub.2OCH.sub.2CH(OH)—(CH.sub.2).sub.n—CH(OH)CH.sub.2OCH.sub.2—R.sup.1—CH.sub.2—R.sup.2  (1)

(in the formula (1), n is an integer of 2 to 6, R.sup.1 is a perfluoropolyether chain, R.sup.2 is —OCH.sub.2CH(OH)CH.sub.2O(CH.sub.2).sub.mOH (m in the formula is an integer of 2 to 4)).

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 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 fluorine-containing ether compound represented by a formula (1) shown below.
R.sup.4—CH.sub.2—R.sup.3—CH.sub.2—R.sup.2—CH.sub.2—R.sup.1—CH.sub.2—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.5  (1) In formula (1), R.sup.1 and R.sup.3 represent the same or different perfluoropolyether chains, R.sup.2 represents a linking group containing at least one polar group, one or both of R.sup.4 and R.sup.5 represent a terminal group containing two or more polar groups, and R.sup.4 and R.sup.5 are different.

A fluorine-containing ether compound represented by a formula (1) shown below.
R.sup.4—CH.sub.2—R.sup.3—CH.sub.2—R.sup.2—CH.sub.2—R.sup.1—CH.sub.2—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.5  (1) In formula (1), R.sup.1 and R.sup.3 represent the same or different perfluoropolyether chains, R.sup.2 represents a linking group containing at least one polar group, one or both of R.sup.4 and R.sup.5 represent a terminal group containing two or more polar groups, and R.sup.4 and R.sup.5 are different.

The present invention relates to a fluorine-containing ether compound represented by Formula (1),
R.sup.1—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4  (1).
(In Formula (1), R.sup.1 is an end group including an organic group having at least one double bond or triple bond, R.sup.2 is a divalent linking group bonded to R.sup.1 by etheric oxygen, R.sup.3 is a perfluoropolyether chain, R.sup.4 is an end group having two or three polar groups with each polar group being bonded to different carbon atoms, and the carbon atoms, to which the polar groups are bonded, being bonded to each other via a linking group including carbon atoms to which the polar groups are not bonded.)

The present application provides quaternary azeotrope or azeotrope-like compositions comprising trans-dichloroethylene and three or more additional components. Methods of using the compositions provided herein in cleaning, defluxing, deposition, and carrier fluid applications are also provided.