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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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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A fluorine-containing ether compound represented by a formula (1) shown below.

R.sup.1—(O(CH.sub.2).sub.a).sub.b-[A]-[B]—O—CH.sub.2—R.sup.2—CH.sub.2—R.sup.3  (1)

(In the formula (1), R.sup.1 is an alkyl group which may have a substituent, or an organic group having at least one double bond or triple bond. Further, a represents an integer of 2 to 4, and b is 0 or 1. [A] is represented by a formula (2): —(OCH.sub.2CH(OH)CH.sub.2).sub.c— (wherein c is 1 or 2). [B] is represented by a formula (3): —(O(CH.sub.2).sub.eCH(OH)CH.sub.2).sub.d— (wherein d is 0 or 1, and e represents an integer of 2 to 4). However, the sum of c in the formula (2) and d in the formula (3) is 2. R.sup.2 is a perfluoropolyether chain. R.sup.3 is represented by a formula (4): —(OCH.sub.2CH(OH)CH.sub.2).sub.2—O—CH.sub.2(CH.sub.2).sub.fOH (wherein f represents an integer of 2 to 5).

A fluorine-containing ether compound represented by a formula (1) shown below.

R.sup.1—(O(CH.sub.2).sub.a).sub.b-[A]-[B]—O—CH.sub.2—R.sup.2—CH.sub.2—R.sup.3  (1)

(In the formula (1), R.sup.1 is an alkyl group which may have a substituent, or an organic group having at least one double bond or triple bond. Further, a represents an integer of 2 to 4, and b is 0 or 1. [A] is represented by a formula (2): —(OCH.sub.2CH(OH)CH.sub.2).sub.c— (wherein c is 1 or 2). [B] is represented by a formula (3): —(O(CH.sub.2).sub.eCH(OH)CH.sub.2).sub.d— (wherein d is 0 or 1, and e represents an integer of 2 to 4). However, the sum of c in the formula (2) and d in the formula (3) is 2. R.sup.2 is a perfluoropolyether chain. R.sup.3 is represented by a formula (4): —(OCH.sub.2CH(OH)CH.sub.2).sub.2—O—CH.sub.2(CH.sub.2).sub.fOH (wherein f represents an integer of 2 to 5).

Provided is a raw material powder for powder metallurgy, capable of preventing stains, surface defects and decarburization of a sintered body, improving strength and density thereof. The raw material powder for powder metallurgy is for use in the production of a sintered body that is sintered at a temperature of not lower than 500° C., composed of a mixture of a metal powder and a lubricant, in which the lubricant is melamine cyanurate or terephthalic acid. Alternatively, the raw material powder for powder metallurgy is for use in the production of a sintered body that is sintered at a temperature of not lower than 500° C, composed of a mixture of a metal powder, a first lubricant and a second lubricant, in which the first lubricant is melamine cyanurate or terephthalic acid, while the second lubricant is preferably erucic acid amide or stearic acid amide.

Provided is a raw material powder for powder metallurgy, capable of preventing stains, surface defects and decarburization of a sintered body, improving strength and density thereof. The raw material powder for powder metallurgy is for use in the production of a sintered body that is sintered at a temperature of not lower than 500° C., composed of a mixture of a metal powder and a lubricant, in which the lubricant is melamine cyanurate or terephthalic acid. Alternatively, the raw material powder for powder metallurgy is for use in the production of a sintered body that is sintered at a temperature of not lower than 500° C, composed of a mixture of a metal powder, a first lubricant and a second lubricant, in which the first lubricant is melamine cyanurate or terephthalic acid, while the second lubricant is preferably erucic acid amide or stearic acid amide.

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##

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##

A climate-control system can be used to heat or cool a space. The climate-control system may include first and second vessels between which refrigerant and co-fluid may be circulated. The refrigerant may be absorbed into the co-fluid within the first vessel at a first rate. The refrigerant may desorb from the co-fluid within the second vessel at a second rate. Ultrasonic energy may be used to adjust the second rate to substantially match the first rate.

One aspect of the present invention is a lubricant to be incorporated into a powder metallurgical mixed powder containing an iron-based powder. The lubricant includes a flaky organic material having an average particle diameter of from 0.1 μm to less than 3 μm. Another aspect of the present invention is a powder metallurgical mixed powder which contains an iron-based powder and the lubricant. Yet another aspect of the present invention is a method for producing a sintered compact. The method includes the step of mixing materials to give a powder metallurgical mixed powder containing an iron-based powder and the lubricant. The powder metallurgical mixed powder is compacted using a die to give a powder compact. The powder compact is sintered to give a sintered compact.