Provided are a fluoropolyether compound having high heat resistance and capable of maintaining a surface protection layer even under high temperature, and a lubricant and a magnetic disk that contain the fluoropolyether compound. The fluoropolyether compound includes: three groups whose main chain contains a perfluoropolyether chain; and a trivalent linking group represented by Formula (1) below, the three groups being bound together via the trivalent linking group:

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where R.sub.1 is a saturated hydrocarbon group having 1 to 3 carbon atoms, a perfluoroalkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or an amino group, and A.sub.1, A.sub.2, and A.sub.3 are each independently an aromatic group.

A fluorine-containing ether compound according to the present invention is a fluorine-containing ether compound represented by the following General Formula (1). ##STR00001##

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

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 is an aryl group or an aralkyl group, R.sup.2 is a divalent linking group having 0 or 1 polar group, R.sup.3 is a perfluoropolyether chain, R.sup.4 is a divalent linking group having 2 or 3 polar groups, and R.sup.5 is an aryl group or an aralkyl group.)

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

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

In formula (1), R.sup.2 is a perfluoropolyether chain represented by a formula (2) shown below. R.sup.1 is a terminal group that is bonded to R.sup.2 via a CH.sub.2 group, and is represented by a formula (3) shown below. R.sup.3 is bonded to R.sup.2 via a CH.sub.2 group, is a terminal group having at least one hydroxyl group, and may be the same as, or different from, R.sup.1.

—(CF.sub.2).sub.p-1—O—((CF.sub.2).sub.pO).sub.q—(CF.sub.2).sub.p-1—  (2)

In formula (2), p represents an integer of 2 to 3, and q indicates the average polymerization degree and is a number within a range from 1 to 20.

—O(CH.sub.2—CH(OH)—CH.sub.2—O).sub.2—CH.sub.2—(CH.sub.2).sub.n,—OH  (3)

In formula (3), n represents an integer of 1 to 8.

According to one aspect of the present invention, an organic fluorine compound is represented by a general formula
(R-π-E-CH.sub.2-A-CH.sub.2-E′).sub.n-π′-G  (1B) (where n is an integer of 2 to 5, A is a divalent perfluoropolyether group, π is an arylene group or a single bond, R is an alkenyl group or an alkynyl group, and E and E′ are each independently an ether bond or an ester bond or a group that is represented by a chemical formula
—O—CH.sub.2CH(OH)CH.sub.2O—
π′ is a group in which n+1 hydrogen atoms are separated from benzene, G is an organic group containing a fullerene skeleton, the n number of groups each of which is represented by a general formula
R-π-E-CH.sub.2-A-CH.sub.2-E′-
may be the same or different, and at least one π among the n number of π is an arylene group).

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

C.sub.6H.sub.6-n—[O—R.sup.1—O—CH.sub.2—R.sup.2—CH.sub.2—R.sup.3].sub.n  (1)

(in the formula (1), n is an integer of 2 or 3, R.sup.1 is any one of —CH.sub.2CH.sub.2—, —CH.sub.2CH.sub.2CH.sub.2— and —CH.sub.2CH(OH)CH.sub.2—, R.sup.2 is a perfluoropolyether chain, R.sup.3 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 for a magnetic recording medium capable of forming a lubricant layer having excellent adhesion to a protective layer is provided. A lubricant for a magnetic recording medium contains a fluorine-containing ether compound in which a group having an ethylenic carbon-carbon double bond is disposed at one or both terminals of a perfluoroalkyl polyether chain. It is preferable that the group having the ethylenic carbon-carbon double bond is disposed at one terminal of the perfluoroalkyl polyether chain, and a hydroxyl group is disposed at other terminal. It is preferable that the lubricant for a magnetic recording medium contains a compound in which one or more functional groups selected from a hydroxyl group, an amino group, an amido group and a carboxyl group is disposed at one or both terminals of a perfluoroalkyl polyether chain.

Provided are a magnetic disk and, in particular, a compound which makes it possible to realize a lubricant having excellent heat resistance and solubility in a fluorine-based solvent. A perfluoropolyether compound in accordance with an aspect of the present invention has, in hydrocarbon groups at both terminals thereof, five or six hydroxyl groups in total.

A fluorine-containing ether 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  (1)

(R.sup.1 is an organic group having an alicyclic structure having 3 to 13 carbon atoms; R.sup.2 is represented by the following formula (2), and a in the formula (2) is an integer of 1 to 3; R.sup.3 is a perfluoropolyether chain; and 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.)

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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.1—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.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.)

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