Fluorine-containing ether compound, lubricant for magnetic recording medium, and magnetic recording medium
A fluorine-containing ether compound characterized by being represented by the following formula (1): R 1 —R 2 —CH 2 —R 3 —CH 2 —R 4 —R 5 (1) In the formula (1), R 3 is a perfluoropolyether chain. R 2 and R 4 are divalent linkage groups having a polar group and may be the same or different. R 1 and R 5 are bonded to an atom other than a carbon atom of R 2 or R 4 . R 1 and R 5 are terminal groups composed of an organic group having 1 to 8 carbon atoms and may be the same or different. At least one of R 1 and R 5 is a chain organic group having 1 to 8 carbon atoms wherein one or more hydrogen atoms of the chain organic group is substituted with a group having an amide bond.
1. A fluorine-containing ether compound represented by the following formula (1),
R 1 —R 2 —CH 2 —R 3 —CH 2 —R 4 —R 5 (1)
wherein in the formula (1), R 3 is a perfluoropolyether chain; R 2 and R 4 are divalent linkage groups having a polar group and may be the same or different; R 1 and R 5 are bonded to an atom other than a carbon atom of R 2 or R 4 ; R 1 and R 5 are terminal groups composed of an organic group having 1 to 8 carbon atoms and may be the same or different; and at least one of R 1 and R 5 is a chain organic group having 1 to 8 carbon atoms wherein one or more hydrogen atoms of the chain organic group is substituted with a group having an amide bond.
2. The fluorine-containing ether compound according to claim 1 , wherein the chain organic group is an alkyl group having 1 to 4 carbon atoms.
3. The fluorine-containing ether compound according to claim 1 , wherein the polar group is a hydroxy group.
4. The fluorine-containing ether compound according to claim 1 , wherein R 2 and R 4 in the formula (1) are represented by the following formula (2-1),
—(O—CH 2 CH(OH)CH 2 ) a —O— (2-1)
wherein in the formula (2-1), a represents an integer of 1 to 3.
5. The fluorine-containing ether compound according to claim 1 , wherein in the formula (1), R 1 is a chain organic group having 1 to 8 carbon atoms wherein one or more hydrogen atoms of the chain organic group are substituted with a group having an amide bond, and
R 5 is an alkyl group in which one or more hydrogen atoms are substituted with a polar group.
6. The fluorine-containing ether compound according to claim 1 , wherein in the formula (1), R 3 is any one of the following formulas (3) to (5),
—CF 2 O—(CF 2 CF 2 O) c —(CF 2 O) d —CF 2 — (3)
wherein in the formula (3), c and d represent an average degree of polymerization and each represents 0 to 20, provided that c or d is 0.1 or more,
—CF(CF 3 )—(OCF(CF 3 )CF 2 ) e —OCF(CF 3 )— (4)
wherein in the formula (4), e represents an average degree of polymerization and represents 0.1 to 20,
—CF 2 CF 2 —(OCF 2 CF 2 CF 2 ) f —OCF 2 CF 2 — (5)
wherein in the formula (5), f represents an average degree of polymerization and represents 0.1 to 20.
7. The fluorine-containing ether compound according to claim 1 , wherein a number average molecular weight is in the range of 500 to 10,000.
8. A lubricant for magnetic recording media comprising the fluorine-containing ether compound according to claim 1 .
9. A magnetic recording medium in which at least a magnetic layer, a protective layer, and a lubricant layer are sequentially provided on a substrate, wherein the lubricant layer contains the fluorine-containing ether compound according to claim 1 .
10. The magnetic recording medium according to claim 9 , wherein an average film thickness of the lubricant layer is 0.5 nm to 2 nm.