WO2014126107A1

WO2014126107A1 - Fluorinated ether composition, surface modifier, surfactant, liquid composition, and article

Info

Publication number: WO2014126107A1
Application number: PCT/JP2014/053206
Authority: WO
Inventors: 輝磯部; 健二石関; 佳幸牛頭; 陽司中島; 俊文柿内; 橘　ゆう子
Original assignee: 旭硝子株式会社
Priority date: 2013-02-13
Filing date: 2014-02-12
Publication date: 2014-08-21
Also published as: JPWO2014126107A1; US20150337228A1; JP6142915B2

Abstract

Provided are: a fluorinated ether composition having both high lubricity and a high adhesion property; a lubricant, a surface modifier or a surfactant, each comprising the fluorinated ether composition; and a liquid composition containing the fluorinated ether composition. A fluorinated ether composition comprising a fluorinated ether compound (A) represented by the formula: (X)_n-Y^A-(Z)_m and a fluorinated ether compound (B) represented by the formula: (X)_s-Y^B-(Z)_t, wherein the amount of the fluorinated ether compound (A) relative to the total amount of the fluorinated ether compound (A) and the fluorinated ether compound (B) is 15 to 80 mass%. In the formulae, X represents HO-CH₂-P¹-[(C_aF_2aO)_b(CFQ¹CF₂O)_c]-; Z represents R-P²-[((C_dF_2dO)_e(CFQ²CF₂O)_f]-; n represents 5 or 6 and m represents an integer of 0 to 10, wherein the sum total of n and m (i.e., n + m) is an integer of 5 to 16; and s represents an integer of 0 to 4 and t represents an integer of 0 to 10, wherein the sum total of s and t (i.e., s + t) is an integer of 2 to 14.

Description

Fluorinated ether composition, surface modifier, surfactant, liquid composition, article

The present invention includes a fluorine-containing ether composition useful as a surface modifier, a surfactant, and the like, a surface modifier or surfactant containing the fluorine-containing ether composition, the fluorine-containing ether composition and a solvent. The present invention relates to an article having a liquid composition and a film comprising the fluorine-containing ether composition on a substrate.

In the magnetic disk, a carbon protective film is formed on a magnetic recording layer on which information is recorded for the purpose of protecting the recorded information. Further, for the purpose of protecting the magnetic disk and the read head, a lubricant is applied thereon to form a film (hereinafter also referred to as “surface layer”). As the lubricant, a compound having a modified perfluoropolyether structure has been conventionally used.
As the storage capacity of a recent hard disk drive (hereinafter also referred to as “HDD”) increases, the distance between the magnetic disk, which is a recording medium, and the read head is getting closer as they come into contact with each other. The magnetic disk rotates at a speed exceeding 10,000 rotations per minute. As the magnetic disk and the read head approach each other and the rotation speed is increased, the required performance for the surface layer has been further increased. For example, in order to bring the disk and the head closer, it is important to reduce the thickness of the surface layer. Further, since the contact frequency increases due to the approach, a surface layer with higher lubricity is required. On the other hand, high-speed rotation requires high adhesion to the magnetic disk so that the surface layer does not scatter from the magnetic disk.

However, high lubricity and high adhesion are often contradictory properties, and it is difficult to achieve both.
For example, as a method for improving the lubricity of the surface layer, a method using a lubricant having a low molecular weight and a low viscosity, or a low-polarity lubricant having a low content of polar functional groups or no polar functional groups is used. A method is mentioned. However, when a lubricant having a low molecular weight and a low viscosity is used, the lubricant is volatilized due to the high vapor pressure, and the adhesion between the surface layer and the carbon protective film is low. In addition, when a low-polarity lubricant is used, there is a concern that the durability of the surface layer may be significantly reduced, such as low adhesion due to low polarity and low-level adhesion of the lubricant due to rotation of the magnetic disk. .
As a method for improving the adhesion of the surface layer to the magnetic disk, a method using a lubricant having a high content of polar functional groups can be mentioned. However, when such a lubricant is used, there is a concern that the viscosity of the surface layer is high, the lubricity is remarkably lowered, and the magnetic disk is worn.
For such problems, for example, Patent Documents 1 and 2 propose using a specific fluorine-containing ether compound as a lubricant. Examples of Patent Document 1 include trifunctional fluorine-containing ether compounds having three —CF ₂ CH ₂ OH terminals, and hexafunctional fluorine-containing ethers having three —CH ₂ CH (OH) CH ₂ OH terminals. Compounds are disclosed. Patent Document 2 discloses a bi- to tetra-functional fluorine-containing ether compound having 2, 3 or 4 —CF ₂ —CH ₂ OH ends.

International Publication No. 2005/068534 International Publication No. 2010/027096

According to the lubricant disclosed in Patent Documents 1 and 2, etc., it is said that high lubricity and high adhesion can be achieved to some extent. However, there is still room for improvement in the effect.
According to the study by the present inventors, a bifunctional to tetrafunctional fluorine-containing ether compound having a —CF ₂ CH ₂ OH terminal is excellent in lubricity but not sufficient in adhesion. The hexafunctional fluorine-containing ether compound having three —CH ₂ CH (OH) CH ₂ OH ends has a high viscosity of the formed surface layer and low lubricity. There is also a problem that it is difficult to form a thin surface layer.

The present invention has been made in view of the above circumstances, and includes a fluorinated ether composition capable of achieving both high lubricity and high adhesion, a surface modifier, a surfactant, and a liquid state using the fluorinated ether composition. It is an object to provide compositions and articles.

The present invention provides a fluorinated ether composition, a surface modifier, a surfactant, a liquid composition and an article having the following constitutions [1] to [15].
[1] A fluorine-containing ether compound (A) represented by the following formula (A) and a fluorine-containing ether compound (B) represented by the following formula (B):
The content of the fluorine-containing ether compound (A) is 15 to 80% by mass with respect to the total amount of the fluorine-containing ether compound (A) and the fluorine-containing ether compound (B). Fluorine ether composition.
(X) _n -Y ^A- (Z) _m (A)
(X) _s -Y ^B- (Z) _t (B)
However, the symbols in the formulas have the following meanings.
In the formula (A), X is a group represented by the following formula (X), Z is a group represented by the following formula (Z), n is 5 or 6, and m is 0 to 10 N + m is an integer of 5 to 16, and Y ^A is an (n + m) -valent linking group.
In the formula (B), X and Y have the same meaning as described above, s is an integer of 0 to 4, t is an integer of 0 to 10, s + t is an integer of 2 to 14, Y ^B is a (s + t) -valent linking group.
HO—CH ₂ —P ¹ — [(C _a F _2a O) _b (CFQ ¹ CF ₂ O) _c ] — (X)
RP ² -[(C _d F _2d O) _e (CFQ ² CF ₂ O) _f ]-(Z)
In the formula (X), a is an integer of 1 to 5, b is an integer of 1 to 100, c is an integer of 0 to 100, and P ¹ does not include any of a hydroxy group and an alkoxy group. A divalent linking group or a single bond, Q ¹ is a halogen atom other than a fluorine atom, a hydrogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or an etheric oxygen atom inserted between carbon-carbon atoms A fluoroalkyl group; When b is 2 or more, b a existing in the same molecule may be the same or different. When c is 2 or more, c Q ¹ existing in the same molecule may be the same or different. The arrangement of b (C _a F _2a O) units and c (CFQ ¹ CF ₂ O) units in the molecule may be in any order.
In the formula (Z), d is an integer of 1 to 5, e is an integer of 1 to 100, f is an integer of 0 to 100, and P ² does not include any of a hydroxy group and an alkoxy group. Q ² is a halogen atom other than a fluorine atom, a hydrogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or an etheric oxygen atom inserted between carbon-carbon atoms. R is a fluoroalkyl group, and R is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or a fluoroalkyl group in which an etheric oxygen atom is inserted between carbon-carbon atoms. When e is 2 or more, e ds present in the same molecule may be the same or different. If f is 2 or more, f-number of Q ² to which exist in the same molecule may be the same as or different from each other. The arrangement of the e (C _d F _2d O) units and the f (CFQ ² CF ₂ O) units in the molecule may be in any order.

[2] The fluorine-containing ether composition according to [1], wherein the total number average molecular weight of the fluorine-containing ether compound (A) and the fluorine-containing ether compound (B) is 500 to 50,000.
[3] The number average molecular weight of the fluorine-containing ether compound (A) is 2,000 to 50,000, and the molecular weight distribution (Mw / Mn) is 1.00 to 1.65. [1] or [2 ] A fluorine-containing ether composition.
[4] The number average molecular weight of the fluorinated ether compound (B) is 500 to 10,000, and the molecular weight distribution (Mw / Mn) is 1.00 to 1.65. Any fluorine-containing ether composition.

[5] In the fluorine-containing ether compound (A), m in the formula (A) is an integer of 0 to 3, X is a group represented by the following formula (X-1), Z is the following formula (Z— The fluorine-containing ether composition according to any one of [1] to [4], which is a compound that is a group represented by 1).
HO—CH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _b-1 − (X-1)
R—O— (CF ₂ CF ₂ O) _e − (Z-1)
However, the symbols in the formulas have the following meanings.
In the formula (X-1), b is an integer of 1 to 100.
In the formula (Z-1), e is an integer of 1 to 100, and R has the same meaning as described above.
[6] wherein Y ^A is a 5 or 6-valent polyhydric alcohol from the structure except for the hydroxy group groups were perfluorinated, perfluoro organic group, fluorine-containing ether composition of [5].

[7] In the fluorine-containing ether compound (B), s is 4 in the formula (B), t is 0 to 2, X is a group represented by the following formula (X-1), and Z is The fluorine-containing ether composition according to any one of [1] to [6], which is a compound which is a group represented by Z-1).
HO—CH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _b-1 − (X-1)
R—O— (CF ₂ CF ₂ O) _e − (Z-1)
However, the symbols in the formulas have the following meanings.
In the formula (X-1), b is an integer of 1 to 100.
In the formula (Z-1), e is an integer of 1 to 100, and R has the same meaning as described above.
[8] The fluorinated ether composition according to [7], wherein Y ^B is a perfluoro organic group obtained by fluorinating a group having a structure in which a hydroxy group is removed from a tetravalent to hexavalent polyhydric alcohol.

[9] A surface modifier or surfactant comprising the fluorine-containing ether composition according to any one of [1] to [8].
[10] A lubricant for magnetic recording media comprising the fluorine-containing ether composition according to any one of [1] to [8].
[11] A liquid composition comprising the fluorinated ether composition according to any one of [1] to [8] above and a liquid medium.
[12] The liquid composition according to [11], wherein the concentration of the fluorine-containing ether composition is 0.005 to 50% by mass.
[13] The liquid composition according to [11] or [12], wherein the liquid medium is a fluorinated organic solvent selected from fluoroalkanes, fluoroaromatic compounds and fluoroalkyl ethers.
[14] Applying the liquid composition of any one of [11] to [13] to the surface of the substrate, and then removing the liquid medium to form a film made of the fluorine-containing ether composition on the surface of the substrate. A coating method characterized by the above.
[15] An article comprising a film made of the fluorine-containing ether composition according to any one of [1] to [8] on a substrate.

According to the present invention, it is possible to provide a fluorinated ether composition capable of achieving both high lubricity and high adhesion, and a surface modifier, a surfactant, a liquid composition, and an article using the fluorinated ether composition.

In this specification, a compound represented by the formula (A) is referred to as a compound (A). The same applies to compounds represented by other formulas.
In the present specification, a group represented by the formula (X) is referred to as a group (X). Groups represented by other formulas are also described in the same manner.
The “fluorinated ether composition” in the present invention is a composition composed of two or more fluorine-containing ether compounds. Being composed of a fluorine-containing ether compound means that it contains no components other than the fluorine-containing ether compound except for inevitable impurities.
The “fluorinated ether compound” in the present invention is an ether compound having a poly (oxyperfluoroalkylene) chain.
The “fluoroalkyl group” in the present invention is a group in which some or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms, and the “perfluoroalkyl group” means that all of the hydrogen atoms of the alkyl group are fluorine atoms. Is a group substituted.
The “fluoroalkylene group” in the present invention is a group in which some or all of the hydrogen atoms of the alkylene group are substituted with fluorine atoms, and the “perfluoroalkylene group” means that all of the hydrogen atoms of the alkylene group are fluorine atoms. Is a group substituted.
The number average molecular weight and molecular weight distribution in the present invention are values measured by gel permeation chromatography. As the measurement conditions, the conditions described in Examples described later can be adopted.

[Fluorine-containing ether composition]
The fluorine-containing ether composition of the present invention comprises a fluorine-containing ether compound (A) (hereinafter also referred to as “compound (A)”) and a fluorine-containing ether compound (B) represented by the following formula (B) (hereinafter referred to as “the compound (A)”). , Also referred to as “compound (B)”),
The content of the compound (A) is 15 to 80% by mass with respect to the total amount of the compound (A) and the compound (B).

(Compound (A))
Compound (A) is a compound of n monovalent group (X) and the m univalent groups (Z) is bonded to Y ^A.
(X) _n -Y ^A- (Z) _m (A)

In formula (A), X is a group represented by the following formula (X).
HO—CH ₂ —P ¹ — [(C _a F _2a O) _b (CFQ ¹ CF ₂ O) _c ] — (X)

In the formula (X), a is an integer of 1 to 5, preferably an integer of 2 to 4, and particularly preferably 2. When a is an integer of 3 to 5, C _a F _2a may have a linear structure or a branched structure.
b represents the number of (C _a F _2a O) units and is an integer of 1 to 100, preferably an integer of 5 to 50, particularly preferably an integer of 5 to 30.
c represents the number of (CFQ ¹ CF ₂ O) units, and is an integer of 0 to 100, preferably an integer of 0 to 50, and particularly preferably 0 to 10.

When b is 2 or more, b a existing in the same molecule may be the same or different. That is, the b (C _a F _2a O) units may be the same or different.
When c is 2 or more, c Q ¹ existing in the same molecule may be the same or different. That is, the c (CFQ ¹ CF ₂ O) units may be the same or different.

When b + c is 2 or more, b (C _a F _2a O) units and c (CFQs) in — [(C _a F _2a O) _b (CFQ ¹ CF ₂ O) _c ] — in the molecule ^{The order of 1} CF ₂ O) units may be in any order.
For example, when one (C _a F _2a O) unit and one (CFQ ¹ CF ₂ O) unit are present, the unit to which HO—CH ₂ —P ¹ — is bonded is (C _a F _2a O). ) Unit or (CFQ ¹ CF ₂ O) unit.
When (C _a F _2a O) units and (CFQ ¹ CF ₂ O) units are present and at least one unit is present in two or more units, the arrangement of these units may be random even if it is in a block form It may be a shape.

In formula (X), P ¹ is a divalent linking group containing neither a hydroxy group nor an alkoxy group, or a single bond.
The divalent linking group containing neither a hydroxy group nor an alkoxy group is preferably a divalent organic group containing neither a hydroxy group nor an alkoxy group. Specific examples include an alkylene group and a carbon-carbon atom. Examples include alkylene groups having an etheric oxygen atom inserted, fluoroalkylene groups, fluoroalkylene groups having an etheric oxygen atom inserted between carbon-carbon atoms, those having heteroatoms such as phosphazene, and unsaturated hydrocarbon groups. .
P ¹ is preferably a single bond.

In formula (X), Q ¹ is a halogen atom other than a fluorine atom, a hydrogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or a fluoroalkyl group in which an etheric oxygen atom is inserted between carbon-carbon atoms. .
Examples of the halogen atom other than the fluorine atom include a chlorine atom, an iodine atom, and a bromine atom, and a chlorine atom is preferable from the viewpoint of easy production.
The monovalent hydrocarbon group may be saturated or unsaturated, and is preferably a saturated hydrocarbon group (alkyl group). The structure of the hydrocarbon group may be any of a straight chain structure, a branched chain structure, a ring structure, and a structure having a partial ring structure, preferably a linear structure or a branched chain structure, and particularly preferably a linear structure. The hydrocarbon group preferably has 1 to 10 carbon atoms.
The fluoroalkyl group may be a fluoroalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom or a perfluoroalkyl group. The carbon number of the fluoroalkyl group is preferably 1 to 100, and particularly preferably 1 to 20.
The fluoroalkyl group in the fluoroalkyl group in which an etheric oxygen atom is inserted between carbon-carbon atoms may be a fluoroalkyl group in which a part of the hydrogen atom of the alkyl group is substituted with a fluorine atom or a perfluoroalkyl group. The fluoroalkyl group preferably has 2 to 100 carbon atoms, particularly preferably 2 to 20 carbon atoms.
Specific examples of the fluoroalkyl group in which an etheric oxygen atom is inserted between carbon-carbon atoms include the following group (Q-1).
R ^1- (OC _h F _2h ) _j- (Q-1)
In the formula, R ¹ is a fluoroalkyl group, h is an integer of 1 to 5, j is an integer of 1 to 100, and the total number of carbon atoms of the group (Q-1) is 100 or less.
When h is an integer of 3 to 5, C _h F _2h may have a linear structure or a branched structure.
R ¹ may be a fluoroalkyl group or a perfluoroalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom. The fluoroalkyl group has 1 or more carbon atoms and an integer such that the total number of carbon atoms in the group (Q-1) is 100 or less, preferably 1 to 6.

As the group (X), a in the formula (X) is 2 (provided that (C _a F _2a O bonded to P ¹ only, a is 1)), b is an integer of 1 to 100, and c is 0 to 10, P ¹ is preferably a single bond or —CH ₂ OCH ₂ —.
As the group (X), the following groups (X-1) or (X-2) are more preferable.
HO—CH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _b-1 − (X-1)
HO—CH ₂ —CH ₂ OCH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _b−1 − (X-2)

In formulas (X-1) to (X-2), b is an integer of 1 to 100, preferably an integer of 5 to 50, particularly preferably an integer of 5 to 30.
Among these, as the group (X), the group (X-1) is particularly preferable because it is easy to produce and the compound is difficult to decompose and is stable.

In the formula (A), Z is a group represented by the following formula (Z).
RP ² -[(C _d F _2d O) _e (CFQ ² CF ₂ O) _f ]-(Z)

In the formula (Z), d is an integer of 1 to 5, preferably an integer of 2 to 4, and particularly preferably 2. When d is an integer of 3 to 5, C _d F _2d may have a linear structure or a branched structure.
e represents the number of (C _d F _2d O) units and is an integer of 1 to 100, preferably an integer of 5 to 50, particularly preferably an integer of 5 to 30.
f represents the number of (CFQ ² CF ₂ O) units, and is an integer of 0 to 100, preferably an integer of 0 to 50, and particularly preferably 0 to 10.

When e is 2 or more, e ds present in the same molecule may be the same or different. That is, the e (C _d F _2d O) units may be the same or different.
If f is 2 or more, f-number of Q ² to which exist in the same molecule may be the same as or different from each other. That is, the f (CFQ ² CF ₂ O) units may be the same or different.

When e + f is 2 or more, e (C _d F _2d O) units and f (CFQ) in — [(C _d F _2d O) _e (CFQ ² CF ₂ O) _f ] — in the molecule sequence of ² CF ₂ O) units may be any order.
For example, when one (C _d F _2d O) unit and one (CFQ ² CF ₂ O) unit are present, the unit to which R—P ² — is bonded is the (C _d F _2d O) unit. It may be a (CFQ ² CF ₂ O) unit.
When (C _d F _2d O) -units and (CFQ ² CF ₂ O) units are present and at least one unit is present in two or more units, the arrangement of these units may be in the form of a block It may be random.

In formula (Z), P ² is a divalent linking group or a single bond that does not contain either a hydroxy group or an alkoxy group.
Examples of the divalent linking group containing neither a hydroxy group nor an alkoxy group include a divalent organic group containing neither a hydroxy group nor an alkoxy group, —O—, and the like. Specific examples of the organic group include the same ones as mentioned in P ^1.
P ² is preferably —O—.

In formula (Z), Q ² is a halogen atom other than a fluorine atom, a hydrogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or a fluoroalkyl group in which an etheric oxygen atom is inserted between carbon-carbon atoms. .
Halogen atoms other than fluorine atoms, monovalent hydrocarbon groups, fluoroalkyl groups, and fluoroalkyl groups in which an etheric oxygen atom is inserted between carbon-carbon atoms are the same as those listed for Q ^1. Can be mentioned.

In the formula (Z), R represents a hydrogen atom, a halogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or a fluoroalkyl group in which an etheric oxygen atom is inserted between carbon-carbon atoms.
Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.
The monovalent hydrocarbon group may be saturated or unsaturated, and is preferably a saturated hydrocarbon group (alkyl group). The structure of the hydrocarbon group may be any of a straight chain structure, a branched chain structure, a ring structure, and a structure having a partial ring structure, preferably a linear structure or a branched chain structure, and particularly preferably a linear structure. The hydrocarbon group preferably has 1 to 20 carbon atoms. As the hydrocarbon group, an alkyl group is preferable.
The fluoroalkyl group may be a fluoroalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom or a perfluoroalkyl group. The structure of the fluoroalkyl group may be any of a straight chain structure, a branched chain structure, a ring structure, and a structure having a partial ring structure, preferably a linear structure or a branched chain structure, and particularly preferably a linear structure. The carbon number of the fluoroalkyl group is preferably 1 to 100, and particularly preferably 1 to 10.
The fluoroalkyl group in the fluoroalkyl group in which an etheric oxygen atom is inserted between carbon-carbon atoms may be a fluoroalkyl group in which a part of the hydrogen atom of the alkyl group is substituted with a fluorine atom or a perfluoroalkyl group. The fluoroalkyl group preferably has 2 to 100 carbon atoms, particularly preferably 2 to 10 carbon atoms.
Specific examples of R include the following groups (R-1) to (R-4), and the group (R-1) is preferable.
CF ₃ (CF ₂ ) _p − (R−1)
CF ₃ CF (CF ₃ ) − (R-2)
_{^{_{_{C y F - (CF 2)}}}} q - ... (R-3)
A _d ^F- (CF ₂ ) _r- (R-4)
However, p represents an integer of 0 to 15 (preferably an integer of 0 to 9), C _y ^F represents a perfluorocyclohexyl group, q represents an integer of 0 to 15, and A _d ^F represents a perfluoroadamantyl group. , R represents an integer of 0-15.

In the formula (Z), d is preferably 2, e is an integer of 1 to 100, f is 0 to 10, and P ² is —O—. That is, the group (Z) is preferably the following group (Z-1).
R—O— (CF ₂ CF ₂ O) _e − (Z-1)

In formula (Z-1), e is an integer of 1 to 100, preferably an integer of 5 to 50, particularly preferably an integer of 5 to 30.
R has the same meaning as described above, preferably any one of groups (R-1) to (R-4), and particularly preferably group (R-1).

The group (Z-1) is particularly preferably any of the following groups (Z-11) to (Z-14).
CF ₃ —O— (CF ₂ CF ₂ O) _g − (Z-11)
CF ₃ CF ₂ —O— (CF ₂ CF ₂ O) _g − (Z-12)
CF ₃ (CF ₂ ) ₂ —O— (CF ₂ CF ₂ O) _g − (Z-13)
CF ₃ (CF ₂ ) ₅ —O— (CF ₂ CF ₂ O) _g − (Z-14)

In the formula (A), n is 5 or 6.
m is an integer of 0 to 10, preferably an integer of 0 to 3, particularly preferably 0 or 1.
n + m is an integer of 5 to 16, preferably an integer of 5 to 9, and particularly preferably an integer of 5 to 7. When n + m (the valence of Y ^A ) is in the above range, the adhesion to the substrate is excellent.
The n groups (X) possessed by the compound (A) may be the same or different. When m is 2 or more, m groups (Z) of the compound (A) may be the same or different.

In formula (A), Y ^A is an (n + m) -valent linking group.
The Y ^A, for example, (n + m) valent fluoro saturated hydrocarbon group, a carbon - etheric oxygen atom between carbon atoms are inserted (n + m) valent fluoro saturated hydrocarbon group, (n + m) valent Cyclophosphazene Groups and the like. Among these, an (n + m) -valent fluoro saturated hydrocarbon group or an (n + m) -valent fluoro saturated hydrocarbon group in which an etheric oxygen atom is inserted between carbon-carbon atoms is preferable.

The fluoro saturated hydrocarbon group may be a fluoro saturated hydrocarbon group or a perfluoro saturated hydrocarbon group in which a part of hydrogen atoms of the saturated hydrocarbon group is substituted with a fluorine atom, and a perfluoro saturated hydrocarbon group is preferable. The structure of the perfluoro saturated hydrocarbon group may be any of a branched chain structure, a ring structure and a structure having a partial ring structure, and a branched chain structure is preferred. The perfluoro saturated hydrocarbon group has preferably 2 to 50 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 5 to 20 carbon atoms.

Examples of the perfluoro saturated hydrocarbon group in the perfluoro saturated hydrocarbon group in which an etheric oxygen atom is inserted between carbon-carbon atoms are the same as those described above. The number of etheric oxygen atoms in the perfluoro saturated hydrocarbon group having an etheric oxygen atom inserted between carbon-carbon atoms is not particularly limited, but 1 to 3 is preferable.
Since the etheric oxygen atom exists between carbon and carbon atoms, there is no etheric oxygen atom at the terminal portion of Y ^A bonded to each of the group (X) and the group (Y).

From the viewpoint of the stability of the compound (A), it is preferable that the compound (A) does not have an —OCF ₂ O— structure. Therefore, when Y ^A is a (n + m) -valent fluoro saturated hydrocarbon group or a (n + m) -valent fluoro saturated hydrocarbon group in which an etheric oxygen atom is inserted between carbon-carbon atoms, Y ^A is Preferably no —OCF ₂ O— structure is present.
The absence of the —OCF ₂ O— structure means that the presence of the structure cannot be detected by a normal analysis method ( ¹⁹ F-NMR, etc.).

Specific examples of Y ^A, for example, (n + m) valent polyhydric based on fluorinated and groups of the structure obtained by removing a hydroxy group from an alcohol, group of the structure excluding the substituents attached to the phosphorus atom of cyclophosphazene compound Etc.
The (n + m) -valent polyhydric alcohol may have an etheric oxygen atom. As a group obtained by fluorinating a group having a structure obtained by removing a hydroxy group from an (n + m) -valent polyhydric alcohol, a perfluoro organic group is preferable.
Examples of the (n + m) -valent polyhydric alcohol include sugar alcohols such as glucose, dipentaerythritol and sorbitol.
Specific examples of the group obtained by fluorinating a group having a structure obtained by removing a hydroxy group from an (n + m) -valent polyhydric alcohol include the following groups (Y5-1) and (Y6-1).
Specific examples of the group having a structure obtained by removing the substituent bonded to the phosphorus atom from the cyclophosphazene compound include the following group (Y6-2).

As the compound (A), m in the formula (A) is an integer of 0 to 3, X is a group (X-1) and Z is a group (Z-1), that is, the compound (A- 1) is preferable.
HO—CH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _b-1 − (X-1)
R—O— (CF ₂ CF ₂ O) _e − (Z-1)
In the formula (X-1), b is an integer of 1 to 100, preferably an integer of 5 to 50, particularly preferably an integer of 5 to 30.
In formula (Z-1), e is an integer of 1 to 100, preferably an integer of 5 to 50, particularly preferably an integer of 5 to 30.
R has the same meaning as described above.

(X ¹ ) _n -Y ^A1- (Z ¹ ) _m1 (A-1)
In the formula (A-1), X ¹ is a group (X-1), Z ¹ is a group (Z-1), n has the same meaning as described above, and m1 is an integer of 0 to 3 (preferably Is 0 or 1), and Y ^A1 is a (n + m1) -valent linking group.
The n groups (X-1) in the formula may be the same or different. When m1 is 2 or more, m1 groups (Z-1) in the formula may be the same or different.
^Examples of the (n + m1) -valent linking group in Y ^A1 include the same groups as those described for Y ^A.

As the compound (A-1), the following compounds (A-11) to (A-14) are preferred.
(X ¹ ) ₅ -Y ⁵ (A-11)
(X ¹ ) ₅ -Y ⁶ -Z ¹ (A-12)
(X ¹ ) ₆ -Y ⁶ (A-13)
(X ¹ ) ₆ -Y ⁷ -Z ¹ (A-14)
In the formula, X ¹ and Z ¹ have the same meanings as described above, and preferred ranges thereof are also the same. Y ⁵ is a pentavalent linking group, Y ⁶ is a hexavalent linking group, and Y ⁷ is a 7 valent linking group.
Y ⁵ , Y ⁶ , and Y ⁷ may each be the same as the ^5- , 6-, or 7-valent linking groups listed for Y ^A. Specific examples of the pentavalent linking group include a group (Y5-1). Specific examples of the hexavalent linking group include a group (Y6-1) and a group (Y6-2).

The number average molecular weight (Mn) of the compound (A) is preferably 500 to 50,000, particularly preferably 2,000 to 20,000.
The molecular weight distribution (Mw / Mn) of the compound (A) is preferably 1.00 to 1.65, particularly preferably 1.00 to 1.50.
When the number average molecular weight and the molecular weight distribution are within the above ranges, the adhesion to the substrate and the durability are excellent, and the volatility is low.

1 type or 2 types or more may be sufficient as the compound (A) which the fluorine-containing ether composition of this invention contains.
The content of the compound (A) in the fluorine-containing ether composition of the present invention is 15 to 80% by mass, preferably 40 to 60% by mass, based on the total amount of the compound (A) and the compound (B). . When the content is at least the lower limit of the above range, the adhesion of the fluorine-containing ether composition of the present invention to a magnetic disk or the like is excellent. When the content is not more than the upper limit of the above range, the ratio of the compound (B) becomes high, whereby the lubricity of the fluorinated ether composition of the present invention becomes excellent.

(Compound (B))
Compound (B) is a compound the s monovalent group (X) and t pieces of monovalent groups (Z) is bonded to Y ^B.
(X) _s -Y ^B- (Z) _t (B)

The group (X) and the group (Y) are the same as the group (X) and the group (Y) mentioned in the description of the compound (A), respectively.
The group (X) and group (Y) included in the compound (B) may be the same as or different from the group (X) and group (Y) included in the compound (A).

In the formula (B), s is an integer of 0 to 4, preferably an integer of 2 to 4, and particularly preferably 3 or 4.
t is an integer of 0 to 10, preferably an integer of 0 to 3.
s + t is an integer of 2 to 14, preferably an integer of 2 to 10, and particularly preferably an integer of 3 to 6. If s + t (valence of Y ^B) is in the above range, easier to manufacture, boiling also suitable, and excellent lubricity.
When s is 2 or more, the s groups (X) of the compound (B) may be the same or different. When t is 2 or more, t groups (Z) of the compound (B) may be the same or different.

Y ^B is a (s + t) -valent linking group.
Y ^B includes, for example, a (s + t) -valent fluoro saturated hydrocarbon group, a (s + t) -valent fluoro saturated hydrocarbon group in which an etheric oxygen atom is inserted between carbon-carbon atoms, and a (s + t) -valent cyclophosphazene. Groups and the like. Among these, a (s + t) -valent fluoro saturated hydrocarbon group or a (s + t) -valent fluoro saturated hydrocarbon group in which an etheric oxygen atom is inserted between carbon-carbon atoms is preferable.

Examples of the perfluoro saturated hydrocarbon group in the perfluoro saturated hydrocarbon group in which an etheric oxygen atom is inserted between carbon-carbon atoms are the same as those described above. The number of etheric oxygen atoms in the perfluoro saturated hydrocarbon group having an etheric oxygen atom inserted between carbon-carbon atoms is not particularly limited, but 1 to 3 is preferable.
Since the etheric oxygen atom exists between carbon-carbon atoms, there is no etheric oxygen atom at the terminal portion of Y ^B bonded to each of the group (X) and the group (Y).

From the viewpoint of stability of the compound (B), it is preferable that the —OCF ₂ O— structure does not exist in the compound (B). Therefore, when Y ^B is a (s + t) -valent fluoro saturated hydrocarbon group or a (s + t) -valent fluoro saturated hydrocarbon group in which an etheric oxygen atom is inserted between carbon-carbon atoms, Y ^B is Preferably no —OCF ₂ O— structure is present.

When Y ^B is a trivalent linking group, Y ^B is preferably a perfluoroalkane-triyl group. The carbon number of the perfluoroalkane-triyl group is preferably 1-20, and particularly preferably 3-5. For example, a perfluoro organic group in which a group having a structure in which a hydroxy group is removed from a trihydric alcohol such as glycerin is perfluorinated is exemplified.
Specific examples of the trivalent linking group include the following groups (Y3-1) to (Y3-3). In the formulas (Y3-2) to (Y3-3), k represents an integer of 1 to 10. The three k present in the same molecule may be the same or different from each other.

When Y ^B is a tetravalent linking group, Y ^B is preferably a perfluoroalkane-tetrayl group or a perfluoroalkane-tetrayl group in which an etheric oxygen atom is inserted between carbon-carbon atoms. The carbon number of the perfluoroalkane-tetrayl group is preferably 1-20, and particularly preferably 3-5. For example, a perfluoro organic group obtained by perfluorinating a group having a structure obtained by removing a hydroxy group from a tetrahydric alcohol such as erythritol, pentaerythritol, and diglycerin can be used.
Specific examples of the tetravalent linking group include the following groups (Y4-1) to (Y4-3).

Specific examples of the linking group in the case where Y ^B is a pentavalent linking group include the group (Y5-1) described above.
Specific examples when Y ^B is a hexavalent linking group include, for example, the groups (Y6-1) and (Y6-2) described above.

Compound (B) is a compound in which s in formula (B) is 4, X is group (X-1), and Z is group (Z-1), that is, compound (B-1) shown below. It is preferable.
HO—CH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _b-1 − (X-1)
R—O— (CF ₂ CF ₂ O) _e − (Z-1)
The group (X-1) and the group (Z-1) are the same as the group (X-1) and the group (Z-1) in the compound (A-1), respectively.
The group (X-1) and group (Y-1) possessed by the compound (B-1) are the same as or different from the group (X-1) and group (Y-1) possessed by the compound (A-1), respectively. Also good.

(X ¹ ) ₄ -Y ^B1- (Z ¹ ) _t (B-1)
In the formula (B-1), X ¹ is a group (X-1), Z ¹ is a group (Z-1), t has the same meaning as described above, and Y ^B1 is a (4 + t) -valent linkage. It is a group. T in the formula (B-1) is preferably 0 to 2.
The four groups (X-1) in the formula may be the same or different. When t is 2 or more, t groups (Z-1) in the formula may be the same or different.
^Examples of the (4 + t) -valent linking group in Y ^B1 include the same groups as those described above for Y ^B. In particular, a perfluoro organic group obtained by fluorinating a group having a structure in which a hydroxy group is removed from the above-described tetravalent to hexavalent polyhydric alcohol is preferable.

As the compound (B-1), the following compounds (B-11) and (B-12) are preferred.
(X ¹ ) ₄ -Y ⁴ (B-11)
(X ¹ ) ₄ -Y ⁵ -Z ¹ (B-12)
In the formula, each of X ¹ and Z ¹ has the same meaning as described above, Y ⁴ is a tetravalent linking group, and Y ⁵ is a pentavalent linking group.
Examples of Y ⁴ and Y ⁵ include the same as the tetravalent or pentavalent linking group exemplified for Y ^B.

The number average molecular weight (Mn) of the compound (B) is preferably 500 to 10,000, and particularly preferably 1,000 to 10,000.
The molecular weight distribution (Mw / Mn) of the compound (A) is preferably 1.00 to 1.65, particularly preferably 1.00 to 1.50.
When the number average molecular weight and molecular weight distribution are in the above ranges, the adhesion to the substrate is excellent and the volatility is low.

The compound (B) contained in the fluorine-containing ether composition of the present invention may be one type or two or more types.
The content of the compound (B) in the fluorine-containing ether composition of the present invention is 20 to 85% by mass, preferably 40 to 60% by mass, based on the total amount of the compound (A) and the compound (B). .

In the fluorine-containing ether composition of the present invention, the total content of the compound (A) and the compound (B) is preferably 80 to 100% by mass or more with respect to the total mass of the fluorine-containing ether composition, and 90 to 100 More preferably, it is more preferably 100% by mass or more. When the total content of the compound (A) and the compound (B) is not less than the above lower limit, the adhesion to the substrate and the lubricity are excellent.

In the fluorine-containing ether composition of the present invention, the total number average molecular weight of the compound (A) and the compound (B) is preferably 500 to 50,000, and preferably 1,000 to 20,000. It is particularly preferred. When the total number average molecular weight is within the above range, adhesion to a substrate and lubricity are excellent, volatility is low, and long-term durability is excellent.
The total number average molecular weight is obtained by mixing the compound (A) and the compound (B) in a ratio of the content of the compound (A) and the compound (B) in the fluorine-containing ether composition. Can be confirmed by measuring the number average molecular weight. When the fluorinated ether composition comprises the compound (A) and the compound (B), the total number average molecular weight is the same as the number average molecular weight measured for the fluorinated ether composition.

(Other fluorine-containing ether compounds)
The fluorine-containing ether composition of the present invention may be composed of the compound (A) and the compound (B), and other fluorine-containing ether compounds other than the compound (A) and the compound (B) (hereinafter, “ (It may also be referred to as “compound (C)”).
As the compound (C), known fluorine-containing ether compounds that can be used as a lubricant and the like can be used, and examples thereof include FONBLIN Z TETRAOL (manufactured by Solvay), A-20H (manufactured by MORESCO), and the like. .

(Method for producing fluorine-containing ether composition)
The fluorine-containing ether composition of the present invention can be produced, for example, by mixing the compound (A), the compound (B) and (optionally the compound (C)) at a predetermined mass ratio.
As the compounds (A) and (B), commercially available compounds may be used, or compounds manufactured using a known manufacturing method may be used.
The manufacturing method of a compound (A) is shown below. Compound (B) can be produced by the same production method except that the production raw material is changed to a raw material having a chemical structure corresponding to compound (B).

<Method for Producing Compound (A)>
Compound (A) can be obtained, for example, by changing the production raw material in the method described in International Publication No. 2005/068534, International Publication No. 2010/027096 or the like to a raw material having a chemical structure corresponding to Compound (A). Can be manufactured.
For example Y ^A is (n + m) valent Bae Rufuruoro saturated hydrocarbon group or a carbon - etheric oxygen atom between carbon atoms are inserted (n + m) valent Bae Rufuruoro saturated compound is a hydrocarbon group, WO 2005 / 068534, which can be produced in the same manner as the method for obtaining compound (A-4). Specifically, a compound having a terminal COF is obtained by esterification, liquid phase fluorination, ester decomposition reaction of an ethylene oxide adduct of a polyhydric alcohol, and the compound is treated by the following method 1-1 or 1-2. It can manufacture by performing.
(Method 1-1) A method in which a compound having COF at its end is reacted with an alcohol or water to form an ester or carboxylic acid at the end and then reduced.
(Method 1-2) A method in which a compound having COF at its end is esterified by transesterification with an alcohol and then reduced.
Among these, in the present invention, it is preferable from the viewpoint of production efficiency to adopt the method by transesterification described in Method 1-2.

In the above method, when the ethylene oxide adduct of polyhydric alcohol as a starting material has a group (Z) in a non-fluorinated state in addition to the hydroxy group to which ethylene oxide has been added, the group (X) and the group ( Z) is obtained.
Even when the ethylene oxide adduct of polyhydric alcohol, which is the starting material, does not have a non-fluorinated group (Z), if the conditions of the liquid phase fluorination reaction are severe, a molecular end cleavage reaction occurs. A compound having both the group (X) and the group (Z) may be by-produced.

As ethylene oxide adducts used as starting materials, compounds having various structures and molecular weights are commercially available at low cost and can be easily obtained.
When the fluorine gas concentration in the liquid phase fluorination reaction becomes high, the production ratio of the group (Z) tends to increase. When it is desired to suppress the formation of the compound having the group (Z), the fluorine gas concentration is preferably 5.0 to 50% by volume, particularly preferably 10 to 30% by volume.
The product produced by the reaction is preferably subjected to a purification step as necessary, and unnecessary compounds are preferably removed by purification. Examples of the purification method include a method of removing metal impurities, anion impurities, and the like with an ion-adsorbing polymer, a supercritical extraction method, and a column chromatography method, and a combination of these methods is preferable.

(Function and effect)
The compound (A) is a 5- to 6-functional compound having 5 or 6 hydroxy groups derived from the group (X), which is inferior in lubricity but excellent in adhesion to a magnetic disk or the like. The compound (B) is a 0 to 4 functional compound having 0 to 4 hydroxy groups derived from the group (X), and is inferior in adhesion but excellent in lubricity. The fluorine-containing ether composition of the present invention comprises the compound (A) and the compound (A) in a ratio that the content of the compound (A) is 15 to 80% by mass with respect to the total amount of the compound (A) and the compound (B). By containing B), it is possible to achieve both excellent adhesion of the compound (A) and excellent lubricity of the compound (B).
Therefore, by providing a film (surface layer) containing the fluorine-containing ether composition of the present invention on a substrate such as a magnetic disk, excellent lubricity and excellent durability can be imparted. For example, by providing a surface layer containing the fluorine-containing ether composition of the present invention as a lubricant on the carbon protective film of the magnetic disk, even if the contact frequency increases due to the proximity of the magnetic disk and the read head, the magnetic disk and Lubricity that can protect the read head can be provided. Further, when the magnetic disk is rotated, the lubricant is volatilized, or when the rotational speed of the magnetic disk is increased (for example, more than 10,000 rotations per minute), the lubricant is scattered and the lubrication performance is reduced. Difficult to disappear.

Moreover, according to the fluorine-containing ether composition of the present invention, it is easy to form a surface layer of a thin film (for example, a film thickness of 1 nm or less).
This is considered to be due to the fact that the hydroxy groups of the compounds (A) and (B), particularly the compound (A) are derived from the group (X). That is, when the hydroxy group is derived from the group (X), for example, when it has three —CH ₂ CH (OH) CH ₂ OH ends like a hexafunctional fluorine-containing ether compound disclosed in Patent Document 1. In comparison, the length of one branched chain is short. (For example, when the compound (A) has 6 hydroxy groups and the number average molecular weight is similar to that of the compound, the compound has ₂ hydroxy groups at the end of —CH ₂ CH (OH) CH ₂ OH. Therefore, the length of the group having the terminal is almost twice as long as the group (X).) Since the distance between the hydroxyl group terminals is shortened, when all the hydroxy groups are bonded on the substrate, This is probably because the height of the molecule becomes lower.

(Use)
The fluorine-containing ether composition of the present invention is useful as a surface modifier or a surfactant. Examples of the surface modifier include a lubricant.
The fluorine-containing ether composition of the present invention can be used for applications other than those described above. Other uses include wire covering materials, ink repellents (for example, for printing equipment such as painting and inkjet), semiconductor element adhesives (for example, LOC (lead-on-chip) tape adhesives, semiconductor protective coatings (for example, Moisture-proof coating agent, anti-cracking agent for solder), additives for thin films used in the optical field (for example, pellicle film), lubricants for antireflection films for displays, antireflection films for resists, and the like.

The fluorine-containing ether composition of the present invention is suitably used for applications in which a film (surface layer) containing a fluorine-containing ether composition is formed on a substrate.
The surface layer containing the fluorine-containing ether composition of the present invention contains a fluorine-containing ether compound (compound (A) or the like) having —CH ₂ —OH at the molecular end, and therefore maintains high lubricity. Therefore, functions such as lubricity can be imparted by providing the surface layer on the substrate. Moreover, the formed surface layer has high adhesion to the substrate and is excellent in durability.
The surface layer is transparent, has a low refractive index, and is excellent in heat resistance or chemical resistance.

The shape and material of the base material on which the surface layer is provided are not particularly limited, and those according to the application of the base material on which the surface layer is provided can be used as appropriate. Examples of the use of the substrate provided with the surface layer include various films such as magnetic disks, optical fibers, mirrors, solar cells, optical disks, touch panels, photosensitive and fixing drums, film capacitors, and antireflection films for glass windows. .
As the substrate, a magnetic disk is preferable from the viewpoint of the usefulness of the present invention. As the magnetic disk, for example, a magnetic disk having a base layer, a recording layer, and a diamond-like carbon protective film (DLC film) in this order on a NiP plated substrate (aluminum, glass, etc.) can be mentioned. The thickness of the DLC film is preferably 5.0 nm or less. The average surface roughness (Ra) of the DLC film is preferably 2.0 nm or less.

The film thickness of the surface layer is appropriately set according to the application. For example, in the case of a surface layer formed on a DLC film of a magnetic disk, the film thickness is preferably 0.1 to 2 nm, particularly preferably 0.5 to 1 nm. If the film thickness of the surface layer is not less than the lower limit of the above range, the lubricating effect by the surface layer can be sufficiently obtained. If it is below the upper limit of the said range, it can contribute highly to high-density recording of a magnetic recording medium.
According to the fluorine-containing ether composition of the present invention, it is possible to form a surface layer that exhibits sufficient lubricity even if it is thinned. Therefore, the thinner the surface layer, the higher the utility of the present invention.
The film thickness of the surface layer is obtained by, for example, obtaining an interference pattern of reflected X-rays by the X-ray reflectivity method using an X-ray diffractometer ATX-G for thin film analysis (manufactured by Rigaku), It can be calculated.

A liquid medium may be added to the fluorine-containing ether composition of the present invention to form a liquid composition. In particular, when the fluorine-containing ether composition of the present invention is used for the purpose of forming a surface layer on a substrate as a surface modifier, a liquid composition is added to the fluorine-containing ether composition of the present invention by adding a liquid medium. It is preferable to use it as a product.

[Surface modifier or surfactant]
The surface modifier or surfactant of the present invention (hereinafter collectively referred to as “surface modifier etc.”) includes the fluorinated ether composition of the present invention.
The surface modifier or the like of the present invention may consist only of the fluorine-containing ether composition of the present invention, or may further contain other components.
The content of the fluorinated ether composition of the present invention in the surface modifier and the like of the present invention is preferably 90 to 100% by mass, particularly preferably 100% by mass, based on the total mass of the surface modifier and the like. That is, it is particularly preferable that the surface modifier or the like of the present invention comprises the fluorine-containing ether composition of the present invention.
Furthermore, as other components that may be included, any compound that can be used as a surface modifier or a surfactant and does not correspond to a fluorine-containing ether compound can be used, for example, silane-based, epoxy-based, titanium-based, Examples include aluminum-based coupling agents. When using the fluorine-containing ether composition of this invention as a surface modifier, the adhesiveness of a base material and a compound (A) can be improved by using this coupling agent.

The surface modifier can be used for lubricant applications. In addition, it can be applied to a resin film or sheet and used to control the refractive index of the resin, or to improve the chemical resistance of the resin.
The lubricant is preferably used for a magnetic disk, in particular, for use in applying lubricity by applying on a diamond-like carbon protective film (DLC film) of the magnetic disk.
As the surfactant, for example, it can be used as an additive or leveling agent for lowering the surface tension of a paint, a leveling agent for a polishing liquid, and the like. When added to the paint, it is preferable to add so that the amount of the fluorine-containing ether composition of the present invention relative to the paint is about 0.01 to 5% by mass.

[Liquid composition]
The liquid composition of the present invention includes the fluorinated ether composition of the present invention and a liquid medium.
The liquid composition of the present invention may be a solution, a suspension, or an emulsion, and is preferably a solution.
The concentration of the fluorine-containing ether composition of the present invention in the liquid composition can be appropriately adjusted according to the use, and is preferably 0.005 to 50% by mass with respect to the total mass of the liquid composition, 0.005 Is more preferably 5% by mass, and particularly preferably 0.01-1% by mass. A uniform surface layer can be formed when the concentration of the fluorine-containing ether composition is within the above range.

The liquid medium is not particularly limited as long as it can dissolve or disperse the fluorine-containing ether composition of the present invention, and an organic solvent is preferable. The organic solvent may be a fluorinated organic solvent, a non-fluorinated organic solvent, or may contain both of these solvents.

Examples of the fluorine-based organic solvent include fluoroalkanes, fluoroaromatic compounds, fluoroalkyl ethers, fluoroalkylamines, and fluoroalcohols.
As the fluoroalkane, a compound having 4 to 8 carbon atoms is preferable. Examples of commercially available products include C ₆ F ₁₃ H (AC-2000: product name, manufactured by Asahi Glass Co., Ltd.), C ₆ F ₁₃ C ₂ H ₅ (AC-6000: product name, manufactured by Asahi Glass Co., Ltd.), C ₂ F ₅ CHFCHFCCF. ₃ (Bertrel XF: product name, manufactured by DuPont).
Examples of the fluoroaromatic compound include hexafluorobenzene, trifluoromethylbenzene, perfluorotoluene, bis (trifluoromethyl) benzene, and the like.
As the fluoroalkyl ether, a compound having 4 to 12 carbon atoms is preferable. As the fluoroalkyl ether, hydrofluoroalkyl ether is preferable. Examples of commercially available products include CF ₃ CH ₂ OCF ₂ CF ₂ H (AE-3000: product name, manufactured by Asahi Glass), C ₄ F ₉ OCH ₃ (Novec-7100: product name, manufactured by 3M), C ₄ F ₉ OC ₂ H ₅ (Novec-7200: product name, manufactured by 3M), C ₆ F ₁₃ OCH ₃ (Novec-7300: product name, manufactured by 3M), and the like.
As the fluoroalkylamine, perfluoroalkylamine is preferable, and examples thereof include perfluorotripropylamine and perfluorotributylamine.
Examples of the fluoroalcohol include 2,2,3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, hexafluoroisopropanol and the like.
As the fluorine-based organic solvent, fluoroalkanes, fluoroaromatic compounds, and fluoroalkyl ethers are preferable from the viewpoint of solubility of the fluorine-containing ether compound. Among these, hydrofluoroalkyl ether is particularly preferable because it has a low ozone depletion coefficient.

As the non-fluorine organic solvent, a compound consisting only of hydrogen atoms and carbon atoms and a compound consisting only of hydrogen atoms, carbon atoms and oxygen atoms are preferred, hydrocarbon organic solvents, alcohol organic solvents, ketone organic solvents, Examples include ether organic solvents and ester organic solvents.
As the hydrocarbon organic solvent, hexane, heptane, cyclohexane and the like are preferable.
As the alcohol organic solvent, methanol, ethanol, propanol, isopropanol and the like are preferable.
As the ketone organic solvent, acetone, methyl ethyl ketone, methyl isobutyl ketone and the like are preferable.
As the ether organic solvent, diethyl ether, tetrahydrofuran, tetraethylene glycol dimethyl ether and the like are preferable.
As the ester organic solvent, ethyl acetate, butyl acetate and the like are preferable.
As the non-fluorine organic solvent, a ketone organic solvent is particularly preferable from the viewpoint of the solubility of the fluorine-containing ether compound.

The liquid medium is at least one selected from the group consisting of fluoroalkanes, fluoroaromatic compounds, fluoroalkyl ethers, compounds consisting only of hydrogen atoms and carbon atoms, and compounds consisting only of hydrogen atoms, carbon atoms and oxygen atoms. Some organic solvents are preferred. In particular, a fluorinated organic solvent selected from fluoroalkanes, fluoroaromatic compounds and fluoroalkyl ethers is preferred.
The liquid medium is at least selected from the group consisting of fluoroalkanes that are fluorine-based organic solvents, fluoroaromatic compounds, fluoroalkyl ethers, and compounds that consist of only hydrogen atoms, carbon atoms, and oxygen atoms that are non-fluorine-based organic solvents. One type of organic solvent is preferably contained in a total amount of 90% by mass or more of the entire liquid medium from the viewpoint of enhancing the solubility of the fluorinated ether compound.

The liquid composition may further contain other components other than the fluorine-containing ether composition of the present invention and the solvent, as necessary, as long as the effects of the present invention are not impaired.
Examples of other components when the fluorine-containing ether composition of the present invention is used as a lubricant include radical scavengers (for example, trade name: X-1p manufactured by Dow Chemicals).

Since the liquid composition may not achieve the desired performance, it is preferable that the liquid composition does not contain metal ions, anions, moisture, low-molecular polar compounds, and the like.
Metal ions (Na, K, Ca, Al, etc.) may combine with an anion to produce a Lewis acid catalyst and promote the decomposition reaction of the fluorinated ether compound. Anions (F, Cl, NO ₂ , NO ₃ , PO ₄ , SO ₄ , C ₂ O ₄ etc.) and moisture may corrode the surface of the substrate. Therefore, the water content in the liquid composition is preferably 2,000 ppm or less. Low molecular polar compounds (alcohols; plasticizers eluted from the resin, etc.) may reduce the adhesion between the substrate and the surface layer.

As a method of using the liquid composition, a known method can be applied depending on the purpose.
For example, when the fluorine-containing ether composition of the present invention is used as a surface modifier, the liquid composition containing the fluorine-containing ether composition of the present invention is applied on a substrate and dried, whereby the present invention is obtained. It is preferable to form a film (surface layer) containing the fluorine-containing ether composition to develop the intended function.
The base material which apply | coats the liquid composition of this invention is not specifically limited, For example, the thing similar to what was mentioned above as a base material which provides a surface layer is mentioned. As the substrate, a magnetic disk is preferable from the viewpoint of the usefulness of the present invention.

Examples of the coating method of the liquid composition include a roll coating method, a casting method, a dip coating method, a spin coating method, a water casting method, a die coating method, a Langmuir-projet method, a vacuum deposition method, and the like. The dip coating method or the vacuum deposition method is preferable.
Examples of the drying method include natural drying, vacuum drying, centrifugal drying, and heat drying.

After the liquid composition is applied on the substrate to form a surface layer, an adhesion treatment may be performed to firmly adhere the fluorine-containing ether compound to the substrate (for example, the carbon protective film of the magnetic disk). Good.
Examples of the adhesion treatment include heat treatment, infrared irradiation treatment, ultraviolet irradiation treatment, and plasma treatment. Heat treatment or ultraviolet irradiation treatment is preferable, and heat treatment is particularly preferable. The drying process may also serve as an adhesion process.
Furthermore, the substrate after the adhesion treatment may be washed with a fluorinated organic solvent for the purpose of removing deposits and excess fluorine-containing ether compound.

[Articles]
The article of the present invention has a film made of the fluorine-containing ether composition of the present invention on a substrate.
The base material which apply | coats the liquid composition of this invention is not specifically limited, For example, the thing similar to what was mentioned above as a base material which provides a surface layer is mentioned. As the substrate, a magnetic disk is preferable from the viewpoint of the usefulness of the present invention.
As a method of providing the film on the substrate, a known method can be used as a method of forming a film made of the fluorine-containing ether composition. For example, the film can be formed by a method of forming the surface layer by applying the liquid composition of the present invention described above onto a substrate.

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited by these examples. Examples 1, 5 and 6 are examples, and examples 2 to 4 are comparative examples.
The evaluation method used in each example is shown below.

〔Evaluation methods〕
(GPC analysis)
The number average molecular weight (Mn) and the molecular weight distribution (Mw / Mn) were measured by gel permeation chromatography (hereinafter also referred to as “GPC”). In addition, Mw shows a mass average molecular weight.
Measurement by GPC was performed under the following conditions according to the method described in JP-A No. 2001-208736.
Mobile phase: Mixed solvent of R-225 (Asahi Glass Co., Ltd., Asahi Clin AK-225 SEC grade 1) and hexafluoroisopropyl alcohol (R-225: hexafluoroisopropyl alcohol = 99: 1 (volume ratio)).
Analytical column: Two PLgel MIXED-E columns (manufactured by Polymer Laboratories) connected in series.
Standard sample for molecular weight measurement: 4 types of perfluoropolyethers with Mw / Mn of less than 1.1 and Mn of 2,000 to 10,000, and perfluoro with Mw / Mn of 1.1 or more and Mn of 1,300 1 type of polyether.
Mobile phase flow rate: 1.0 mL / min.
Column temperature: 37 ° C.
Detector: Evaporative light scattering detector.

(NMR analysis)
NMR analysis was performed under the following conditions.
Nitrobenzene was used at 7.5 ppm as a reference substance for ¹ H-NMR (300.4 MHz).
^As a reference substance for ¹⁹ F-NMR (282.7 MHz), perfluorobenzene was used at −162.5 ppm.
Unless otherwise stated, R-113 (CCl ₂ FCClF ₂ ) was used as the NMR solvent.

(Dynamic friction coefficient measurement)
The dynamic friction coefficient of the outermost surface of the article provided with the surface layer on the base material (the place where the surface layer was provided among the surfaces of the article) was measured using a friction measuring device (manufactured by Heidon, Tribogear). As a contact, a SUS ball having a diameter of 10 mm was used, and measurement was performed at a load of 100 g, a moving distance of 20 mm, and a moving speed of 1 mm / second.

(Measurement of F / Si)
The coverage of the surface layer provided on the substrate (silicon wafer) was evaluated by F / Si measured under the following measurement conditions by X-ray Photoelectron Spectroscopy (XPS: X-ray Photoelectron Spectroscopy).
XPS makes it possible to enter characteristic X-rays such as Al and Mg into a sample and measure the kinetic energy and intensity of photoelectrons emitted by the photoelectric effect. Is a way to know.
The kinetic energy Ek of the photoelectrons emitted from the sample is a value obtained by subtracting the binding energy Eb and the work function W from the incident x-ray energy hν (h: Planck constant, ν: frequency) (Ek = hν−Eb−W). It is. The bond energy Eb is a value that depends on the type, electron orbit, and chemical bond state of the atoms in which the photoelectrons are captured in the sample. The energy hν and work function W of the incident X-ray are known. Therefore, if the kinetic energy Ek is measured, the bond energy Eb can be obtained, and the type, electron orbit, and chemical bond state of atoms in the sample can be known.
Incident X-rays penetrate to a depth of about several μm. However, electrons emitted from atoms in deep locations lose energy due to inelastic scattering with electrons bound to other atoms in the sample, and are not emitted from the sample. For this reason, electrons emitted from the outermost surface with a depth of about several nanometers determined by the inelastic mean free path (the distance traveled without causing inelastic scattering) are observed as photoelectrons. Therefore, XPS is a method for measuring the type, amount, and chemical bonding state of atoms existing on the outermost surface of a sample with high sensitivity, and can detect an extremely thin film coated on a substrate with high sensitivity. This is an effective method for evaluating the coverage of the material.
When the XPS measurement of the outermost surface of an article obtained by each example described later (an article in which a silicon wafer is used as a base material and a surface layer is provided on the base material with a surface modifier containing a fluorine-containing ether compound) At the place covered with the surface layer on the substrate, the photoelectron intensity (hereinafter referred to as F1s peak intensity) emitted from the 1s orbit of fluorine atoms in the surface layer is detected strongly, and the silicon atoms in the substrate The photoelectron intensity emitted from the Si2p orbit (hereinafter referred to as Si2p peak intensity) is weakly detected or not detected. On the other hand, photoelectrons emitted from fluorine atoms are not detected at locations not covered with the surface layer on the substrate, and the intensity of photoelectrons emitted from Si2p orbitals of silicon atoms is detected strongly. Therefore, the ratio of F atom concentration and Si atom concentration calculated from the F1s peak intensity and Si2p peak intensity obtained by XPS measurement is considered to have a positive correlation with the coverage of the surface layer provided on the substrate. be able to.

<XPS measurement conditions>
As the XPS apparatus, PHI Quantera SXM manufactured by ULVAC-PHI was used. Using an AlK _α ray (1486.6 eV) focused to a diameter of about 50 μm as an X-ray source, measurement was performed at an irradiation X-ray intensity of 12.4 W, a detector pass energy of 224 eV, and a photoelectron extraction angle of 45 °. Irradiation X-rays were fixed and measured without scanning, and the outermost surface of the sample was measured, and the sample was not etched. Note that an electron beam attached to the apparatus and an Ar ⁺ neutralization gun were used for charge correction accompanying photoelectron emission from the sample. The F1s peak intensity was calculated using the binding energy 682 to 691 eV, and the Si2p peak intensity using the integrated intensity of the peak with the background removed in the energy range of the binding energy 96 to 107 eV. Furthermore, F atom concentration and Si atom concentration were calculated using the relative sensitivity coefficient of each element unique to the apparatus.

[Synthesis Example 1: Synthesis of fluorinated ether compound (A)]
The following compound (A6-1) was synthesized by the following procedure.
Ethylene oxide was added to dipentaerythritol by a known method to obtain an ethylene oxide adduct.
The ethylene oxide adduct was reacted with FCOCF (CF ₃ ) OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ F (hereinafter also referred to as “RfF”) to obtain an esterified product.
The esterified product (30 g) was dissolved in R-113 (270 g) and fluorinated using fluorine gas diluted to 20% with nitrogen gas (hereinafter also referred to as “20% fluorine gas”). The solvent was distilled off from the product under reduced pressure to obtain a liquid fluorinated product at room temperature.
1,1,3,4-Tetrachlorohexafluorobutane and KF were added to the fluorinated product, and the mixture was vigorously stirred and hydrolyzed at 120 ° C. to obtain a liquid decomposition product at room temperature.
KF and R-113 were added to the decomposition product, and ethanol was added to react for 8 hours while maintaining the temperature so that the temperature did not fall below 25 ° C. Then, KF, R-113 and ethanol were removed to remove ethyl ester. Got.
R-225 and tetrahydrofuran (200 mL) were mixed with the ethyl ester compound, borane / tetrahydrofuran complex was added under a nitrogen stream, and the mixture was reacted overnight (reduction reaction) at room temperature. Thereafter, the solvent was distilled off with an evaporator, 2 mol / L hydrochloric acid was added to the residue, extraction was performed with R-225, and the extract was concentrated to obtain a crude product (59.71 g).

The obtained crude product was purified with a silica gel column (method described in Examples of JP2009-197210A) and then supercritically purified (method described in Examples of JP2009-197210A). It was.
The purified product (compound (A6-1)) was subjected to NMR analysis ( ¹ H-NMR and ¹⁹ F-NMR) and GPC analysis. The NMR analysis results are shown below. Mn of the purified product was 5,867 (average value of b1 to b6: 7.1), and Mw / Mn was 1.10.
¹ H-NMR δ (ppm): 3.94.
¹⁹ F-NMR δ (ppm): −80.1, −88.2 to −90.5, −135.0 to −139.0.

[Synthesis Example 2: Synthesis of fluorinated ether compound (B)]
The following compound (B4-1) was synthesized by the following procedure.
Diglycerin-initiated polyoxyethylenetetraol (Sakamoto Yakuhin Kogyo Co., Ltd., “diglycerin-initiated polyoxyethylene glyceryl ether SC-E1500”) was reacted with RfF to obtain an esterified product.
The esterified product (30 g) was dissolved in R-113 (270 g) and fluorinated using 20% fluorine gas. The solvent was distilled off from the product under reduced pressure to obtain a liquid fluorinated product at room temperature.
1,1,3,4-Tetrachlorohexafluorobutane and KF were added to the fluorinated product, and the mixture was vigorously stirred and hydrolyzed at 120 ° C. to obtain a liquid decomposition product at room temperature.
KF and R-113 are added to the degradable organism, and ethanol is added to react for 8 hours while maintaining the temperature so that the temperature does not fall below 25 ° C. Then, KF, R-113 and ethanol are removed to remove the ethyl ester form. Got.
R-225 and tetrahydrofuran (200 mL) were mixed with the ethyl ester compound, and borane / tetrahydrofuran complex was added under a nitrogen stream, and the mixture was reacted overnight (reduction reaction) at room temperature. The solvent was distilled off with an evaporator, 2 mol / L hydrochloric acid was added to the residue, extraction was performed with R-225, and the extract was concentrated to obtain a crude product (51.58 g).

The obtained crude product was purified with a silica gel column (method described in Examples of JP2009-197210A) and then supercritically purified (method described in Examples of JP2009-197210A). It was.
The purified product (compound (B4-1)) was subjected to NMR analysis ( ¹ H-NMR and ¹⁹ F-NMR) and GPC analysis. The NMR analysis results are shown below. Mn of the purified product was 2,593 (average value of b7 to b10: 3.9), and Mw / Mn was 1.07.
¹ H-NMR δ (ppm): 3.94.
¹⁹ F-NMR δ (ppm): −80.1, −88.2 to −90.5, −135.0 to −139.0.

[Example 1]
(Production of fluorinated ether composition 1)
The compound (A6-1) obtained in Synthesis Example 1 and the compound (B4-1) obtained in Synthesis Example 2 were mixed at a mass ratio of (A6-1) :( B4-1) = 55: 45. The fluorinated ether composition 1 was produced by sufficiently stirring.

(Manufacture of liquid composition 1)
The fluorinated ether composition 1 was dissolved in Vertrel-XF (manufactured by DuPont) to a concentration of 0.05% by mass to prepare a liquid composition 1.

(Manufacture of article 1)
The liquid composition 1 was applied to a silicon wafer by dip coating to obtain an article (substrate with a surface layer) 1. The dip coater used was a micro speed dip coater manufactured by SDI, dipped at a speed of 10 mm / second, dipped for 60 seconds, and then pulled up at a speed of 2 mm / second. The pulled silicon wafer was heated in an oven at 150 ° C. for 10 minutes to form a surface layer, whereby an article 1 was obtained.

(Evaluation)
For article 1, the dynamic friction coefficient, F / Si, of the outermost surface (the place where the surface layer was provided on the article surface) was measured. The results are shown in Table 1. Table 2 shows the outermost surface composition (atomic%) of the article 1 measured by XPS.

[Examples 2 to 6]
Fluorinated ether compositions 2 to 6 were obtained in the same manner as in Example 1 except that the mass ratio of the compound (A6-1) to the compound (B4-1) was changed to the values shown in Table 1.
Liquid compositions 2 to 6 were produced in the same manner as in Example 1 except that the fluorinated ether compositions 2 to 6 were used in place of the fluorinated ether composition 1, and articles 2 to 6 were obtained using the liquid compositions 2 to 6. The dynamic friction coefficient and F / Si were measured for 2-4. The results are shown in Table 1. Table 2 shows the outermost surface composition (atomic%) of articles 2 to 4 measured by XPS.

The article 1 obtained in Example 1 had a low coefficient of dynamic friction on the outermost surface, and the surface layer had high lubricity. Further, the article 1 has an F atom concentration of 25.6 atomic% and an Si atom concentration of 29.7 atomic% in the outermost surface composition, and the F / Si value is significantly higher than that of Example 2, and the surface layer The coverage of the substrate surface due to was high. Since the coverage was high, it was confirmed that the amount of the fluorine-containing ether composition 1 adhered to the substrate surface was sufficient, and the adhesion to the substrate was excellent. From these results, it was confirmed that the fluorine-containing ether composition 1 can exhibit excellent lubricity and adhesion.
On the other hand, the article 2 of Example 2 obtained using the fluorine-containing ether composition 2 having a content of the compound (A) of 10% by mass had high surface layer lubricity, but the F / Si value was small. There was little adhesion amount to the base-material surface of the fluorine-containing ether composition 2, and it was inferior to adhesiveness.
Articles 3 and 4 of Examples 3 and 4 obtained by using the fluorine-containing ether compositions 3 and 4 having a content ratio of the compound (A) of 85 and 98% by mass as the fluorine-containing ether compound have a F / Si value of Although it was large, the coefficient of dynamic friction was large, and the lubricity of the surface layer was insufficient.
Further, in the articles 5 and 6 of Examples 5 and 6 obtained by using the fluorinated ether compositions 5 and 6 in which the content ratio of the compound (A) is 45 and 70% by mass as the fluorinated ether compound, F / Si Although the value is larger than Articles 1 and 2 (similar to Articles 3 and 4), the fluorinated ether compositions 5 and 6 require particularly high lubricity because the dynamic friction coefficient is smaller than that of Article 1. Suitable for intended use.

The fluorine-containing ether composition of the present invention is useful as a surface modifier and a surfactant, and particularly useful as a lubricant for magnetic recording media such as hard disks.
The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2013-025906 filed on February 13, 2013 are incorporated herein as the disclosure of the specification of the present invention. It is.

Claims

A fluorine-containing ether compound (A) represented by the following formula (A) and a fluorine-containing ether compound (B) represented by the following formula (B),
The content of the fluorine-containing ether compound (A) is 15 to 80% by mass with respect to the total amount of the fluorine-containing ether compound (A) and the fluorine-containing ether compound (B). Fluorine ether composition.
(X) n -Y A- (Z) m (A)
(X) s -Y B- (Z) t (B)
However, the symbols in the formulas have the following meanings.
In the formula (A), X is a group represented by the following formula (X), Z is a group represented by the following formula (Z), n is 5 or 6, and m is 0 to 10 N + m is an integer of 5 to 16, and Y A is an (n + m) -valent linking group.
In the formula (B), X and Y have the same meaning as described above, s is an integer of 0 to 4, t is an integer of 0 to 10, s + t is an integer of 2 to 14, Y B is a (s + t) -valent linking group.
HO—CH 2 —P 1 — [(C a F 2a O) b (CFQ 1 CF 2 O) c ] — (X)
RP 2 -[(C d F 2d O) e (CFQ 2 CF 2 O) f ]-(Z)
In the formula (X), a is an integer of 1 to 5, b is an integer of 1 to 100, c is an integer of 0 to 100, and P 1 does not include any of a hydroxy group and an alkoxy group. A divalent linking group or a single bond, Q 1 is a halogen atom other than a fluorine atom, a hydrogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or an etheric oxygen atom inserted between carbon-carbon atoms A fluoroalkyl group; When b is 2 or more, b a existing in the same molecule may be the same or different. When c is 2 or more, c Q 1 existing in the same molecule may be the same or different. The arrangement of b (C a F 2a O) units and c (CFQ 1 CF 2 O) units in the molecule may be in any order.
In the formula (Z), d is an integer of 1 to 5, e is an integer of 1 to 100, f is an integer of 0 to 100, and P 2 does not include any of a hydroxy group and an alkoxy group. Q 2 is a halogen atom other than a fluorine atom, a hydrogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or an etheric oxygen atom inserted between carbon-carbon atoms. R is a fluoroalkyl group, and R is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group, a fluoroalkyl group, or a fluoroalkyl group in which an etheric oxygen atom is inserted between carbon-carbon atoms. When e is 2 or more, e ds present in the same molecule may be the same or different. If f is 2 or more, f-number of Q 2 to which exist in the same molecule may be the same as or different from each other. The arrangement of the e (C d F 2d O) units and the f (CFQ 2 CF 2 O) units in the molecule may be in any order.
The fluorine-containing ether composition according to claim 1, wherein the total number average molecular weight of the fluorine-containing ether compound (A) and the fluorine-containing ether compound (B) is 500 to 50,000.
The content of claim 1, wherein the fluorine-containing ether compound (A) has a number average molecular weight of 2,000 to 50,000 and a molecular weight distribution (Mw / Mn) of 1.00 to 1.65. Fluorine ether composition.
The number average molecular weight of the fluorine-containing ether compound (B) is 500 to 10,000, and the molecular weight distribution (Mw / Mn) is 1.00 to 1.65. The fluorine-containing ether composition as described.
In the fluorine-containing ether compound (A), m in the formula (A) is an integer of 0 to 3, X is a group represented by the following formula (X-1), and Z is the following formula (Z-1). The fluorine-containing ether composition according to any one of claims 1 to 4, which is a compound which is a group represented.
HO—CH 2 —CF 2 O— (CF 2 CF 2 O) b-1 − (X-1)
R—O— (CF 2 CF 2 O) e − (Z-1)
However, the symbols in the formulas have the following meanings.
In the formula (X-1), b is an integer of 1 to 100.
In the formula (Z-1), e is an integer of 1 to 100, and R has the same meaning as described above.
Wherein Y A is a 5 or 6-valent polyhydric alcohol from the structure except for the hydroxy group groups were perfluorinated, perfluoro organic group, fluorine-containing ether composition according to claim 5.
In the fluorine-containing ether compound (B), s is 4 in the formula (B), t is 0 to 2, X is a group represented by the following formula (X-1), and Z is the following formula (Z-1 The fluorine-containing ether composition according to any one of claims 1 to 6, which is a compound which is a group represented by
HO—CH 2 —CF 2 O— (CF 2 CF 2 O) b-1 − (X-1)
R—O— (CF 2 CF 2 O) e − (Z-1)
However, the symbols in the formulas have the following meanings.
In the formula (X-1), b is an integer of 1 to 100.
In the formula (Z-1), e is an integer of 1 to 100, and R has the same meaning as described above.
The fluorinated ether composition according to claim 7, wherein Y B is a perfluoro organic group obtained by fluorinating a group having a structure in which a hydroxy group is removed from a tetravalent to hexavalent polyhydric alcohol.
A surface modifier or surfactant comprising the fluorine-containing ether composition according to any one of claims 1 to 8.
A magnetic recording medium lubricant comprising the fluorine-containing ether composition according to any one of claims 1 to 8.
A liquid composition comprising the fluorinated ether composition according to any one of claims 1 to 8 and a liquid medium.
The liquid composition according to claim 11, wherein the concentration of the fluorine-containing ether composition is 0.005 to 50% by mass.
The liquid composition according to claim 11 or 12, wherein the liquid medium is a fluorinated organic solvent selected from fluoroalkanes, fluoroaromatic compounds and fluoroalkyl ethers.
The liquid composition according to any one of claims 11 to 13 is applied to a substrate surface, and then the liquid medium is removed to form a film made of the fluorine-containing ether composition on the substrate surface. Application method.
An article comprising a film comprising the fluorine-containing ether composition according to any one of claims 1 to 8 on a substrate.