Fluorine-containing ether compound, lubricant for magnetic recording medium, and magnetic recording medium
The fluorine-containing ether compound is represented by the following formula (1): R 1 —R 2 —CH 2 —R 3 —CH 2 —R 4 . In the formula (1), R 1 is represented by the following formula (2), R 2 is represented by the following formula (3), R 3 is a perfluoropolyether chain, and R 4 is an organic end group different from R 1 —R 2 — and contains 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 one another via a linking group containing a carbon atom to which the polar group is not bonded. In the formula (2), R 5 is an alkoxy group selected from the group consisting of a methoxy, an ethoxy and a propoxy group. In the formula (3), w is 2 or 3.
1. A fluorine-containing ether compound represented by the following formula (1),
R 1 —R 2 —CH 2 —R 3 —CH 2 —R 4 (1)
wherein in the formula (1), R 1 is represented by the following formula (2);
R 2 is represented by the following formula (3);
R 3 is a perfluoropolyether chain; and
R 4 is an organic end group different from R 1 —R 2 — and comprises 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 one another via a linking group containing a carbon atom to which the polar group is not bonded,
wherein in the formula (2), R 5 is an alkoxy group selected from the group consisting of a methoxy, an ethoxy and a propoxy group; and
in the formula (3), w represents 2 or 3.
2. The fluorine-containing ether compound according to claim 1 , wherein all the polar groups of R 4 in the formula (1) are hydroxyl groups.
3. The fluorine-containing ether compound according to claim 1 , wherein R 4 in the formula (1) is an end group represented by any one of the following formulae (4-1) to (4-4),
wherein in the formula (4-1), p1 represents an integer of 1 to 2, and p2 represents an integer of 1 to 5;
in the formula (4-2), s represents an integer of 2 to 5;
in the formula (4-3), t represents an integer of 1 to 5; and
in the formula (4-4), q represents an integer of 2 to 5.
4. The fluorine-containing ether compound according to claim 1 , wherein R 3 in the formula (1) is represented by the following formula (5),
wherein in the formula (5), m and n indicate an average degree of polymerization,
m represents 1 to 30, and
n represents 0 to 30.
5. The fluorine-containing ether compound according to claim 1 , wherein R 3 in the formula (1) is represented by the following formula (6) or the following formula (7),
wherein in the formula (6), u indicates an average degree of polymerization and represents 1 to 30; and
in the formula (7), v indicates an average degree of polymerization and represents 1 to 30.
6. The fluorine-containing ether compound according to claim 1 , wherein the structure of the fluorine-containing ether compound is represented by the following formula (8),
wherein in the formula (8), x and y indicate an average degree of polymerization, and each represents 1 to 20;
z represents 1 or 2;
w represents 2 or 3; and
R 5 is an alkoxy group selected from the group consisting of a methoxy, an ethoxy and a propoxy group.
7. The fluorine-containing ether compound according to claim 1 , wherein R 5 is a methoxy group.
8. The fluorine-containing ether compound according to claim 1 , wherein a number average molecular weight is in the range of 500 to 10000.
9. A lubricant for magnetic recording media, comprising the fluorine-containing ether compound according to claim 1 .
10. 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 .
11. The magnetic recording medium according to claim 10 , wherein an average film thickness of the lubricant layer is 0.5 nm to 2 nm.