A fluorine-containing ether compound represented by 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.4  (1)

(In formula (1), R.sup.1 and R.sup.3 represent different perfluoropolyether chains, R.sup.2 represents a linking group containing one or more polar groups, and R.sup.4 represents a terminal group containing two or more polar groups.)

Grease composition contains (A) a straight-chain perfluoropolyether having a kinematic viscosity of 2-110 mm.sup.2/s at 40° C., (B) a branched perfluoropolyether having a kinematic viscosity of 2-100 mm.sup.2/s at 40° C., and (C) a fluorocarbon resin powder having a primary particle size of 1 μm or less, wherein the contained amount of the fluorocarbon resin powder is 25-40 wt % with respect to the weight of the grease composition, and the weight ratio of the straight-chain perfluoropolyether (A) to the branched perfluoropolyether (B) is 15:85 to 70:30.

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

R.sup.1—O—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4—R.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.g—N—R.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.)

Environmentally friendly refrigerant blends utilizing blends including 2,3,3,3-tetrafluoropropene (HFO-1234yf) and fluoroethane (HFC-161). The blends have ultra-low GWP, low toxicity, and low flammability with low temperature glide or nearly negligible glide for use in a hybrid, mild hybrid, plug-in hybrid, or full electric vehicles for thermal management (transferring heat from one part of the vehicle to the other) of the passenger compartment providing air conditioning (A/C) or heating to the passenger cabin.

There is provided a fluorine-containing ether compound represented by the following formula. R.sup.1—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—OCH.sub.2CH(OH)CH.sub.2O—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4—R.sup.5 (in the formula. R.sup.3 represents a perfluoropolyether chain; R.sup.2 and R.sup.4 represent a divalent linking group having a polar group; R.sup.1 and R.sup.5 represent a terminal group bonded to an oxygen atom of R.sup.2 or R.sup.4; and at least one of R.sup.1 and R.sup.5 is any one selected from the group consisting of an alkenyl group having 2 to 8 carbon atoms, an alkynyl group having 3 to 8 carbon atoms, an aromatic hydrocarbon-containing group, and an aromatic heterocycle-containing group).

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.) ##STR00001##

Low-friction fluorinated coatings are disclosed herein. A preferred low-friction material contains a low-surface-energy fluoropolymer having a surface energy between about 5 mJ/m.sup.2 to about 50 mJ/m.sup.2, and a hygroscopic material that is covalently connected to the fluoropolymer in a triblock copolymer, such as PEG-PFPE-PEG. The material forms a lubricating surface layer in the presence of humidity. An exemplary copolymer comprises fluoropolymers with average molecular weight from 500 g/mol to 20,000 g/mol, wherein the fluoropolymers are (α,ω)-hydroxyl-terminated and/or (α,ω)-amine-terminated, and wherein the fluoropolymers are present in the triblock structure T-(CH.sub.2—CH.sub.2—O)—CH.sub.2—CF.sub.2—O—(CF.sub.2—CF.sub.2—O).sub.m(CF.sub.2—O).sub.n—CF.sub.2—CH.sub.2—(O—CH.sub.2—CH.sub.2).sub.p-T where T is a hydroxyl or amine terminal group, p=1 to 50, m=1 to 100, and n=1 to 100. The copolymer also contains isocyanate species and polyol or polyamine chain extenders or crosslinkers possessing a functionality of preferably 3 or greater. These durable, solvent-resistant, and transparent coatings reduce insect debris following impact.

Provided are a lubricant that is highly resistant to contamination and highly thermally stable, a lubricant that is highly durable and highly heat resistant, and a magnetic disk. A fluoropolyether compound contains perfluoropolyether groups, end groups each containing at least one hydroxyl group, and a linking group that is comprised of a C.sub.4-C.sub.14 hydrocarbon group and that contains at least one hydroxyl group.

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)).