Fluorine-containing ether compounds, lubricants for magnetic recording media, and magnetic recording media

Abstract

This fluorine-containing ether compound is represented by a formula. R1-CH2-R2-(CH2-OCH2-CR3R4-CH2O-CH2-R2)z-CH2-R5 (where z is 1 or 2; R2 is a perfluoropolyether chain; R1 and R5 are each a C1-50 terminal group having at least one polar group; R3 and R4 may be the same or different, and are each a C1-5 organic group that is bonded to a tetrasubstituted carbon atom and that does not include a secondary hydroxyl group or a tertiary hydroxyl group but includes one primary hydroxyl group; and the organic group may include an ether oxygen atom between the carbon atoms, and may have an ether oxygen atom as the terminus for bonding with the tetrasubstituted carbon atom.)

Claims

1. A fluorine-containing ether compound characterized by being represented by the following formula (1). R １ -CH ２ -R ２ -(CH ２ -OCH ２ -CR ３ R ４ -CH ２ O-CH ２ -R ２ ) ｚ -CH ２ -R ５ (1) (In equation (1), z is either 1 or 2.) In equation (1), R ２ These are each independently perfluoropolyether chains represented by the following formula (3). -(CF ２ ) ｗ１ -O-(CF ２ O) ｗ２ -(CF ２ CF ２ O) ｗ３ -(CF ２ CF ２ CF ２ O) ｗ４ -(CF ２ CF ２ CF ２ CF ２ O) ｗ５ -(CF ２ ) ｗ６ - (3) In equation (3), w2, w3, w4, and w5 represent the average degree of polymerization, each independently ranging from 0 to 20. However, it is impossible for all of w2, w3, w4, and w5 to be 0 at the same time. w1 and w6 are CF ２ It is an average value representing the number of such values, each independently representing 1 to 3. It is the repeating unit in equation (3) (CF ２ O), (CF ２ CF ２ O), (CF ２ CF ２ CF ２ O), (CF ２ CF ２ CF ２ CF ２ There are no particular restrictions on the order of the elements in O). In equation (1), R １ and R ５ Each terminal group represented by is independently one of the terminal groups shown in the following formulas (4-1) to (4-3). 【Chemistry 1】 In equation (4-1), y1 is 1 or 2, and y2 is an integer from 0 to 3. １ is an aromatic hydrocarbon group, an unsaturated heterocyclic group, an alkenyl group, an alkynyl group, a hydroxyl group, a group having an amide bond, or a cyano group. When y1 is 1, X １ X is a hydroxyl group, a group having an amide bond, or a cyano group. １ If X is an aromatic hydrocarbon group or an unsaturated heterocyclic group, １ The atoms that make up the ring structure inside are X １ It bonds to the adjacent methylene group. １ If X is an alkenyl group or an alkynyl group, １ The carbon atoms that make up the unsaturated bond inside are X １ It bonds to the adjacent methylene group. In equation (4-2), y3 is an integer between 1 and 3, y4 is 0 or 1, and y5 is an integer between 0 and 3. １ is an aromatic hydrocarbon group, an unsaturated heterocyclic group, an alkenyl group, an alkynyl group, a hydroxyl group, a group having an amide bond, or a cyano group. When y4 is 0, X １ X is a hydroxyl group, a group having an amide bond, or a cyano group. １ If X is an aromatic hydrocarbon group or an unsaturated heterocyclic group, １ The atoms that make up the ring structure inside are X １ It bonds to the adjacent methylene group. １ If X is an alkenyl group or an alkynyl group, １ The carbon atoms that make up the unsaturated bond inside are X １ It bonds to the adjacent methylene group. In equation (4-3), y6 is 0 or 1, y7 is an integer from 1 to 3, and y8 is an integer from 1 to 3. １ is an aromatic hydrocarbon group, an unsaturated heterocyclic group, an alkenyl group, an alkynyl group, a hydroxyl group, a group having an amide bond, or a cyano group. When y6 is 0, X １ X is a hydroxyl group, a group having an amide bond, or a cyano group. １ If X is an aromatic hydrocarbon group or an unsaturated heterocyclic group, １ The atoms that make up the ring structure inside are X １ It bonds to the adjacent methylene group. １ If X is an alkenyl group or an alkynyl group, １ The carbon atoms that make up the unsaturated bond inside are X １ It bonds to the adjacent methylene group. In formulas (4-1) to (4-3), the group having an amide bond is -NR6COR7 or -CONR8R9, where R6, R7, R8, and R9 in the group having an amide bond are each independently selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, a propyl group, and a butyl group. In equation (1), R ３ and R ４ Each of these is independently one of the groups represented by equations (2-1) to (2-3). 【Chemistry 2】 In equation (2-1), a is an integer between 1 and 5. In equation (2-2), b is an integer between 1 and 5. In equation (2-3), c and d are each independent integers between 1 and 4, and c + d ≤ 5.

2. In the above formula (1), z -CR ３ R ４ - Middle R ３ and R ４ The fluorine-containing ether compound according to claim 1, wherein all of the components are identical.

3. The (z+1) Rs in equation (1) above ２ The fluorine-containing ether compound according to claim 1, wherein all of the components are identical.

4. The fluorine-containing ether compound according to claim 1, wherein the number-average molecular weight is in the range of 500 to 10,000.

5. A lubricant for magnetic recording media, characterized by containing a fluorine-containing ether compound as described in any one of claims 1 to 4.

6. A magnetic recording medium having at least a magnetic layer, a protective layer, and a lubricating layer sequentially provided on a substrate, A magnetic recording medium characterized in that the lubricating layer contains a fluorine-containing ether compound according to any one of claims 1 to 4.

7. The magnetic recording medium according to claim 6, wherein the average thickness of the lubricating layer is 0.5 nm to 2.0 nm.

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