Fluorine-containing ether compound, lubricant for magnetic recording medium, and magnetic recording medium

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

R 1 —R 2 —CH 2 —R 3 —CH 2 —R 4 —R 5   (1)

(in Formula (1), R 1 and R 5 each represents a group having a heterocyclic ring, wherein the heterocyclic ring is at least a pyrazole ring, a thiophene ring, a thiazole ring, or a pyridine ring, R 1 and R 5 may be the same as or different from each other, R 2 and R 4 are each represented by Formula (2-1) or (2-2), and R 3 represents a perfluoropolyether chain)

—(O—CH 2 CH(OH)CH 2 ) a —O—  (2-1)

(in Formula (2-1), a represents an integer selected from 1 to 3)

—(O—CH 2 CH(CH 2 OH)CH 2 ) b —O—  (2-2)

(in Formula (2-2), b represents an integer selected from 1 to 3).

2. The fluorine-containing ether compound according to claim 1 , wherein R 3 is represented by any of Formulas (3) to (5)

—CF 2 —(OCF 2 CF 2 ) c —(OCF 2 ) d —OCF 2 —  (3)

(in Formula (3), c and d each represents 0 to 20, where c or d is 0.1 or more)

—CF(CF 3 )—(OCF(CF 3 )CF 2 ) e —OCF(CF 3 )—  (4)

(in Formula (4), e represents 0.1 to 20)

—CF 2 CF 2 —(OCF 2 CF 2 CF 2 ) f —OCF 2 CF 2 —  (5)

(in Formula (5), f represents 0.1 to 20).

3. The fluorine-containing ether compound according to claim 1 , wherein a number-average molecular weight is within a range of 500 to 10000.

4. A lubricant for a magnetic recording medium, comprising:

the fluorine-containing ether compound according to claim 1 .

5. A magnetic recording medium, comprising:

a substrate; and

at least a magnetic layer, a protective layer, and a lubricating layer sequentially provided on the substrate,

wherein the lubricating layer includes the fluorine-containing ether compound according to claim 1 .

6. The magnetic recording medium according to claim 5 ,

wherein an average film thickness of the lubricating layer is 0.5 nm to 2 nm.

7. The fluorine-containing ether compound according to claim 1 , wherein R 1 and R 5 in Formula (1) are each represented by one selected from Formulas (6) to (9)

Z—  (6)

(in Formula (6), Z represents a heterocyclic ring which may have a substituent),

Z—O—(CH 2 ) g —  (7)

(in Formula (7), Z represents a heterocyclic ring which may have a substituent, and g represents an integer selected from 1to 3)

Z—(CH 2 ) h —  (8)

(in Formula (8), Z represents a heterocyclic ring which may have a substituent, and h represents an integer selected from 1 to 3)

Z—(CH 2 ) i —O—(CH 2 ) j —  (9)

(in Formula (9), Z represents a heterocyclic ring which may have a substituent, and i and j each represents an integer selected from 1 to 3),

wherein the heterocyclic ring is at least a pyrazole ring, a thiophene ring, a thiazole ring, or a pyridine ring.

8. The fluorine-containing ether compound according to claim 1 , which is a compound selected from compounds represented by Formulas (A) to (F) and (I) to (L)

(in Formula (A), q and r each represents 0.1 to 20)

(in Formula (B), k and m each represents 0.1 to 20)

(in Formula (C), n and p each represents 0.1 to 20)

(in Formula (D), s and t each represents 0.1 to 20)

(in Formula (E), u and v each represents 0.1 to 20)

(in Formula (F), w and x each represents 0.1 to 20)

(in Formula (I), cc and dd each represents 0.1 to 20)

(in Formula (J), ee and ff each represents 0.1 to 20)

(in Formula (K), gg represents 0.1 to 20)

(in Formula (L), hh represents 0.1 to 20).

9. The fluorine-containing ether compound according to claim 1 , wherein R 2 and R 4 in Formula (1) are each represented by Formula (2-1).

10. The fluorine-containing ether compound according to claim 1 , wherein R 2 and R 4 in Formula (1) are each represented by Formula (2-2).

11. The fluorine-containing ether compound according to claim 1 ,

wherein R 3 is represented by any of Formulas (3) to (5), and R 1 and R 5 in Formula (1) are each represented by one selected from Formulas (6) to (9)

—CF 2 —(OCF 2 CF 2 ) c —(OCF 2 ) d —OCF 2 —  (3)

(in Formula (3), c and d each represents 0 to 20, where c or d is 0.1 or more)

—CF(CF 3 )—(OCF(CF 3 )CF 2 ) e —OCF(CF 3 )—  (4)

(in Formula (4), e represents 0.1 to 20)

—CF 2 CF 2 —(OCF 2 CF 2 CF 2 ) f —OCF 2 CF 2 —  (5)

(in Formula (5), f represents 0.1 to 20)

Z—  (6)

(in Formula (6), Z represents a heterocyclic ring which may have a substituent)

Z—O—(CH 2 ) g —  (7)

(in Formula (7), Z represents a heterocyclic ring which may have a substituent, and g represents an integer selected from 1 to 3)

Z—(CH 2 ) h —  (8)

(in Formula (8), Z represents a heterocyclic ring which may have a substituent, and h represents an integer selected from 1 to 3)

Z—(CH 2 ) i —O—(CH 2 ) j —  (9)

(in Formula (9), Z represents a heterocyclic ring which may have a substituent, and i and j each represents an integer selected from 1 to 3),

wherein the heterocyclic ring is at least a pyrazole ring, a thiophene ring, a thiazole ring, or a pyridine ring.