The present invention relates to polymers obtained by the copolymerization of (per)fluoropolyether (PFPE), tetrafluoroethylene (TFE) and at least one non-homopolymerizable olefin.

The present invention provides 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—R.sup.4—R.sup.5

(in the formula, R.sup.3 represents a perfluoropolyether chain; R.sup.1 and R.sup.5 each independently represent any of an alkyl group which may have a substituent, an organic group having a double bond or a triple bond, and a hydrogen atom; —R.sup.2—CH.sub.2—R.sup.3 is represented by -[A]-[B]—O—CH.sub.2—R.sup.3; R.sup.3—CH.sub.2—R.sup.4— is represented by R.sup.3—CH.sub.2—O—[C]-[D]-; [A] is represented by Formula (4), [B] is represented by Formula (5), [C] is represented by Formula (6), and [D] is represented by Formula (7)):

##STR00001##

The present invention relates to compounds according to formula (Ia) or formula (Ib); ##STR00001##
wherein each W is independently selected from the group consisting of H, F, Cl, Br, I and (CY.sub.2).sub.mCY.sub.3; each Y is independently selected from the group consisting of F, Cl, Br and I; each Z is independently selected from the group consisting of H, OH, (CW.sub.2).sub.pCW.sub.3, CY.sub.3, OCW.sub.3, O(CW.sub.2).sub.pCW.sub.3, OCW((CY.sub.2).sub.mCY.sub.3)CWCW.sub.2, (CW.sub.2).sub.pOH, polyalkylene glycol and polyolester; n is an integer from 2 to 49; m is an integer from 0 to 3; p is an integer from 0 to 9; the molecular weight average (M.sub.W) is ≤5500; and the polydispersity index is ≤1.45; compositions comprising these compounds and methods for their production.

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 and may be the same or different from each other; 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 may be the same or different from each other; and at least one of R.sup.1 and R.sup.5 is an organic group having 1 to 8 carbon atoms and at least one of hydrogens included in the organic group is substituted by a cyano group).

A fluorine-containing ether compound of the present invention is represented by the following General Formula (1). (In the General Formula (1), X is a trivalent atom or a trivalent atom group, A is a linking group including at least one polar group, B is a linking group having a perfluoropolyether chain, and D is a polar group or a substituent having a polar group at the end.)
[Chem. 1]
XA-B-D).sub.3  (1)

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 compound which allows realization of a lubricant having high adsorbability and a high covering property with respect to a magnetic disk, particularly a carbon protective film. A perfluoropolyether compound in accordance with an aspect of the present invention has a naphthyl group or a phenoxyphenyl group at any one of terminals thereof.

An object of an aspect of the present invention is to provide: a lubricant excellent in adsorbability on the surface of a magnetic disk and in contamination resistance; and a magnetic disk which uses the lubricant and which is excellent in durability. The lubricant in accordance with an aspect of the present invention contains a fluoropolyether compound having, at a terminal thereof, a hydroxyalkenyl group or a hydroxyalkynyl group.

An embodiment of the present invention relates to a paste which includes a perfluoropolyether (A) having two or more ethylenically unsaturated bonds in the molecule, a polysiloxane (B) having two or more ethylenically unsaturated bonds in the molecule, and a radical initiator (C).

An embodiment of the present invention relates to a paste which includes a perfluoropolyether (A) having two or more ethylenically unsaturated bonds in the molecule, a polysiloxane (B) having two or more ethylenically unsaturated bonds in the molecule, and a radical initiator (C).