JP7790182B2 - Surface treatment agent, coating liquid, article, and method for manufacturing article - Google Patents

Description

The present invention relates to a surface treatment agent, a coating liquid, an article, and a method for manufacturing an article.

In order to impart water- and oil-repellent properties, stain resistance, etc. to the surface of a substrate, it is known to form a surface layer made of a condensate of a fluorine-containing ether compound on the surface of the substrate by surface treatment using a fluorine-containing ether compound having a fluoropolyether chain and a reactive silyl group (Patent Document 1).

Patent No. 5761305

In recent years, the performance requirements for surface layers formed using fluorinated ether compounds have been increasing. For example, when a surface layer is applied to a member that constitutes a surface that is touched with fingers, the surface layer is required to have excellent lubricity (smoothness when touched with fingers) and excellent abrasion resistance.
The present inventors evaluated a surface layer formed using a fluorine-containing ether compound as described in Patent Document 1 and found that there is room for improvement in at least one of the lubricity and abrasion resistance of the surface layer.

The present invention aims to provide a surface treatment agent, coating liquid, article, and method for manufacturing an article that can form a surface layer with excellent lubricity and abrasion resistance.

As a result of intensive research into the above-mentioned problems, the present inventors have found that, in a surface treatment agent containing a fluorine-containing ether compound having a fluoropolyether chain containing a unit represented by (OCF ₂ ) and a unit represented by (OCF ₂ CF ₂ ), and a reactive silyl group, when the integrated value of the peak corresponding to the fluorine atoms in the units constituting the fluoropolyether chain, obtained by measuring the fluorine-containing ether compound by ¹⁹ F-NMR, satisfies the formula (A-1) described below, the surface treatment agent can form a surface layer excellent in lubricity and abrasion resistance, and have arrived at the present invention.

That is, the inventors have found that the above problems can be solved by the following configuration.
[1] A surface treatment agent containing a fluorine-containing ether compound having a fluoropolyether chain containing a unit represented by (OCF ₂ ) and a unit represented by (OCF ₂ CF ₂ ), and a reactive silyl group,
The surface treatment agent is characterized in that the following formula (A-1) is satisfied in a chart obtained by ¹⁹ F-NMR measurement of the fluorine-containing ether compound:
Y>-0.0062X ² +0.1343X+0.1123...(A-1)
where X and Y are values determined based on a chart obtained by ^19F -NMR measurement of the fluorinated ether compound using 1,4-bistrifluoromethylbenzene as an internal standard,
Chemical shift: a1, the integral value of the peak observed at −50.5 to −51.2 ppm
The integral value of the peak observed at chemical shifts of −52.0 to −52.8 ppm is a2,
The integral value of the peak observed at chemical shifts of −53.8 to −54.5 ppm is a3,
The integral value of the peak observed at chemical shifts of −87.0 to −88.5 ppm is designated as b1,
When the integral value of the peak observed at chemical shifts of −88.8 to −90.2 ppm is defined as b2,
X means {(a1+a2+a3)/2}/{(b1+b2)/4},
Y means (a3)/(a1+a2+a3).
[2] The surface treatment agent according to [1], wherein X in the formula (A-1) is 2 to 8.
[3] The surface treatment agent according to [1] or [2], which satisfies the following formula (A-2) in a chart obtained by ¹⁹ F-NMR measurement of the fluorinated ether compound:
Y>-0.0056X ² +0.1231X+0.2119...(A-2)
However, X and Y in formula (A-2) are the same as X and Y in formula (A-1) above.
[4] A coating liquid comprising the surface treatment agent according to any one of [1] to [3] above and a liquid medium.
[5] An article having a surface layer formed on a substrate from the surface treatment agent according to any one of [1] to [3] above or the coating liquid according to [4] above.
[6] The article according to [5], wherein the article is a touch panel and the surface layer is provided on a surface of a member that constitutes a surface of the touch panel that is touched with a finger.
[7] A method for manufacturing an article, comprising forming a surface layer on a substrate by a dry coating method or a wet coating method using the surface treatment agent according to any one of [1] to [3] above or the coating liquid according to [4] above.

The present invention provides a surface treatment agent, coating liquid, article, and method for manufacturing an article that can form a surface layer with excellent lubricity and abrasion resistance.

This is a graph in which points given by the values of X and Y of each fluorinated ether compound used in the Examples section are plotted in an orthogonal coordinate system in which the horizontal axis represents the value of X in formula (A-1) and the vertical axis represents the value of Y in formula (A-1). 1 is a chart obtained by measuring ¹⁹ F-NMR using the fluorine-containing ether compound mixture 5-1 used in Example 14 in the Examples section.

In this specification, a group represented by formula (g1) may be referred to as group (g1). A structure represented by formula (G1) may be referred to as structure (G1). A compound represented by formula (1-1) may be referred to as compound (1-1). Compounds represented by other formulas may be similarly referred to.
A fluoroalkyl group is a general term that includes perfluoroalkyl groups and partial fluoroalkyl groups. A perfluoroalkyl group refers to a group in which all of the hydrogen atoms of an alkyl group are substituted with fluorine atoms. A partial fluoroalkyl group is an alkyl group in which one or more hydrogen atoms are substituted with fluorine atoms and which also has one or more hydrogen atoms. In other words, a fluoroalkyl group is an alkyl group having one or more fluorine atoms.
The term "reactive silyl group" refers collectively to a hydrolyzable silyl group and a silanol group (Si-OH), and the term "hydrolyzable silyl group" refers to a group that can undergo a hydrolysis reaction to form a silanol group.
The term "organic group" refers to a hydrocarbon group which may have a substituent and which may have a heteroatom or other bond in the carbon chain.
The term "hydrocarbon group" refers to a group consisting of carbon atoms and hydrogen atoms, and includes aliphatic hydrocarbon groups (for example, divalent aliphatic hydrocarbon groups such as linear alkylene groups, branched alkylene groups, and cycloalkylene groups), aromatic hydrocarbon groups (for example, divalent aromatic hydrocarbon groups such as phenylene groups), and groups consisting of combinations thereof.
"Surface layer" means a layer formed on a substrate.
The "molecular weight" of the fluoropolyether chain is a number average molecular weight calculated by ¹ H-NMR and ¹⁹ F-NMR to determine the number (average value) of oxyfluoroalkylene units based on the terminal groups.
The numerical range indicated by "to" means that the numerical values before and after it are included as the lower and upper limits.

In this specification, an alkylene structure containing a fluorine atom sandwiched between two oxygen atoms, such as OCF ₂ CH ₂ —O, is interpreted as having a repeating unit consisting of a partial structure sandwiched between two oxygen atoms and an oxygen atom (in the above case, “OCF ₂ CH ₂ ”).

[Surface treatment agent]
The surface treatment agent of the present invention (hereinafter also referred to as "the present surface treatment agent") is a surface treatment agent containing a fluorine-containing ether compound having a fluoropolyether chain containing a unit represented by (OCF ₂ ) and a unit represented by (OCF ₂ CF ₂ ), and a reactive silyl group, and satisfies formula (A-1) described below in a chart obtained by ¹⁹ F-NMR measurement of the fluorine-containing ether compound.
By using the present surface treatment agent, a surface layer with excellent lubricity and abrasion resistance can be formed.

The present surface treatment agent may contain two or more types of fluorinated ether compounds. In this case, the above chart obtained by ^19F -NMR measurement of the fluorinated ether compound means a chart obtained by measuring a mixture of two or more types of fluorinated ether compounds.

<Formula (A-1)>
Y>-0.0062X ² +0.1343X+0.1123...(A-1)
In formula (A-1), X and Y are values determined based on a chart obtained by ^19F -NMR measurement of the fluorinated ether compound contained in the surface treatment agent using 1,4-bistrifluoromethylbenzene as an internal standard,
The integral value of the peak observed at chemical shifts of −50.5 to −51.2 ppm is a1,
The integral value of the peak observed at chemical shifts of −52.0 to −52.8 ppm is a2,
The integral value of the peak observed at chemical shifts of −53.8 to −54.5 ppm is a3,
The integral value of the peak observed at chemical shifts of −87.0 to −88.5 ppm is designated as b1,
When the integral value of the peak observed at chemical shifts of −88.8 to −90.2 ppm is defined as b2,
X means {(a1+a2+a3)/2}/{(b1+b2)/4},
Y means (a3)/(a1+a2+a3).

The peaks corresponding to a1, a2, a3, b1 and b2 have the following meanings:
Peak corresponding to a1: a peak corresponding to the fluorine atom in (OCF 2 ) located at the center of the sequence represented by -(OCF ₂ CF ₂ )-(OCF ₂ )-(OCF ₂ CF ₂ )- in the sequence of each unit constituting the fluoropolyether chain in the fluorine-containing ether compound. Peak corresponding to a2: a peak corresponding to the fluorine atom in (OCF ₂ ) located at the center of the sequence represented by -(OCF ₂ )-(OCF _{2 )} -(OCF ₂ CF ₂ )- in the sequence of each unit constituting the fluoropolyether chain. Peak corresponding to a3: a peak corresponding to the fluorine atom in (OCF ₂ ) located at the center of the sequence represented by -(OCF ₂ )-(OCF ₂ )-(OCF ₂ )- in the sequence of each unit constituting the fluoropolyether chain. Peaks corresponding to b1 and b2: peaks corresponding to the fluorine atom in (OCF ₂ CF ₂ ).

X means {(a1+a2+a3)/2}/{(b1+b2)/4}, and specifically, is a numerical value indicating the ratio of units represented by (OCF ₂ ) to units represented by (OCF ₂ CF ₂ ) in the fluoropolyether chain. In other words, when X is large, it means that the ratio of units represented by (OCF ₂ ) present in the fluoropolyether chain is high.
Here, (a1+a2+a3) is multiplied by 1/2 and (b1+b2) is multiplied by 1/4 because a1, a2, and a3 are integral values corresponding to two fluorine atoms in (OCF ₂ ), and b1 and b2 are integral values corresponding to four fluorine atoms in (OCF ₂ CF ₂ ).

Y means (a3)/(a1+a2+a3), and specifically, is a numerical value indicating the proportion of structures in which three or more ( _OCF2 )s are arranged consecutively in the sequences containing ( _OCF2 ) in the fluoropolyether chain. In other words, when Y is large, it means that there are many portions in the fluoropolyether chain in which ( _OCF2 )s are arranged consecutively.

Here, an example of a method for obtaining a fluorine-containing ether compound having a large Y is to use a raw material M13 obtained by reacting a compound M11 having a high ratio of units represented by (OCF ₂ ) to units represented by (OCF ₂ CF ₂ ) with a compound M12 having units represented by (OCF ₂ CF ₂ ) during the production of the fluorine-containing ether compound. Since the compound M11 has a high ratio of (OCF ₂ ), the (OCF ₂ ) tend to be arranged continuously. Therefore, by using the compound M11, it is possible to increase the value of Y.
On the other hand, as a method for obtaining a fluorine-containing ether compound having a small Y, for example, a method of using a compound M21 having a low ratio of units represented by (OCF _{2 ) to units represented by (OCF 2 CF 2} ) during the production of the fluorine-containing ether compound. Since the ratio of (OCF ₂ ) in compound M21 is low, (OCF ₂ ) tends to be difficult to be arranged continuously. Therefore, by using compound M21, it is possible to lower the value of Y.

When determining the integral value of a peak in a ¹⁹ F-NMR spectrum, two points on either side of the relevant peak that have no dominant signals are determined in the ¹⁹ F-NMR spectrum, and each integral value is calculated using the line connecting these two points as the baseline.

Here, FIG. 1 is a graph in which points given by the values of X and Y of each fluorinated ether compound used in the Examples section described later are plotted in an orthogonal coordinate system in which the horizontal axis represents the value of X (i.e., {(a1+a2+a3)/2}/{(b1+b2)/4}) and the vertical axis represents the value of Y (i.e., (a3)/(a1+a2+a3)).
Among the points plotted in Fig. 1, the group of points A and the group of points B indicate fluorine-containing ether compounds capable of forming a surface layer excellent in abrasion resistance and lubricity, and the group of points C indicates fluorine-containing ether compounds that form a surface layer insufficient in at least one of abrasion resistance and lubricity. Furthermore, when the group of points A and the group of points B are compared, the use of the fluorine-containing ether compound of the group of points A enables the formation of a surface layer more excellent in abrasion resistance and lubricity.
1 is a curve obtained based on the group of points B and the group of points C plotted on the graph. The curve A-1 corresponds to the above formula (A-1) and is expressed by a quadratic function of Y=-0.0062X ² +0.1343X+0.1123.
The points present on the positive side of the vertical axis from curve A-1 (in FIG. 1, the group of points A and the group of points B) are fluorine-containing ether compounds that satisfy the above formula (A-1), and the points present on curve A-1 and on the negative side of the vertical axis from curve A-1 (in FIG. 1, the group of points C) are fluorine-containing ether compounds that do not satisfy the above formula (A-1).
The curve A-2 in FIG. 1 will be described later.

The present inventors have focused on the parameters X and Y and investigated their relationship with the effects of the present invention, and have found that a predetermined effect can be obtained at the boundary of "Curve A-1."
Here, X simply represents the amount of a unit expressed by (OCF ₂ ), and Y simply represents the amount of (OCF ₂ ) sandwiched between (OCF ₂ ) on both ends. The inventors noticed that when the value of X changes, the value of Y at which a predetermined effect is manifested changes in conjunction with this, and found that the parameters X and Y are closely related, leading to the above curve A-1.

In formula (A-1), X is preferably 0.9 to 8, more preferably 2 to 8, and even more preferably 3 to 6, in order to provide a surface layer with superior abrasion resistance and/or lubricity.

Y in formula (A-1) is less than 1.0, and is preferably 0.10 to 0.90, more preferably 0.46 to 0.85, and even more preferably 0.50 to 0.85, in order to provide a surface layer with superior abrasion resistance and/or lubricity.

<Formula (A-2)>
The fluorine-containing ether compound contained in the present surface treatment agent preferably satisfies the following formula (A-2) in a chart obtained by ¹⁹ F-NMR measurement, thereby providing a surface layer with superior abrasion resistance and/or lubricity.

Y>-0.0056X ² +0.1231X+0.2119...(A-2)
X and Y in formula (A-2) are the same as X and Y in formula (A-1) above.

Here, curve A-2 in Fig. 1 is a curve obtained based on the group of points A and the group of points B plotted on the graph. Equation (A-2) corresponds to curve A-2 in Fig. 1, and curve A-2 is expressed as a quadratic function of Y = -0.0056X ² + 0.1231X + 0.2119.
Points present on the positive side of the vertical axis from curve A-2 (a group of points A in FIG. 1) are fluorine-containing ether compounds that satisfy the above formula (A-2), and points present on curve A-2 and on the negative side of the vertical axis from curve A-2 (a group of points B in FIG. 1) are fluorine-containing ether compounds that do not satisfy the above formula (A-2).
The inventors have focused on the parameters X and Y and investigated their relationship with the effects of the present invention, and have found that the effects of the present invention are further improved at the boundary of "Curve A-2."

<Formula (A-3)>
The fluorine-containing ether compound contained in the present surface treatment agent preferably satisfies the above formula (A-1) and the following formula (A-3) in a chart obtained by ^19F -NMR measurement, and more preferably satisfies the above formula (A-2) and the following formula (A-3), thereby providing a surface layer with particularly excellent abrasion resistance and/or lubricity.
Y<-0.0045X ² +0.098X+0.4645...(A-3)
X and Y in formula (A-3) are the same as X and Y in formula (A-1) above.
The formula (A-3) corresponds to the curve A-3 in FIG. 1, and the curve A-3 is expressed by a quadratic function of Y=-0.0045X ² +0.098X+0.4645.

<Fluorine-containing ether compounds>
The fluorine-containing ether compound contained in the present surface treatment agent has a fluoropolyether chain containing a unit represented by (OCF ₂ ) and a unit represented by (OCF ₂ CF ₂ ), and a reactive silyl group.
Since the fluorine-containing ether compound has a fluoropolyether chain, the surface layer obtained using the fluorine-containing ether compound has excellent water and oil repellency and fingerprint stain removability.
The fluorine-containing ether compound has a reactive silyl group, which forms a strong chemical bond with the substrate, and the resulting surface layer has excellent abrasion resistance.

The fluoropolyether chain preferably has the following structure (G1).
(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 ...(G1)
however,
m11 means the average number of (OCF ₂ ) groups in the fluorinated ether compound and is a positive number of 2 or more;
m12 means the average number of (OCF ₂ CF ₂ ) in the fluorine-containing ether compound and is a positive number of 2 or more.

In formula (G1), the bonding order of (OCF ₂ ) and (OCF ₂ CF ₂ ) is arbitrary. For example, in formula (G1), (OCF ₂ ) and (OCF ₂ CF ₂ ) may be arranged alternately, or (OCF ₂ ) and (OCF ₂ CF ₂ ) may be arranged in blocks, or may be random.
m11 is a positive number of 2 or more, preferably a positive number from 2 to 100, more preferably a positive number from 3 to 80, and even more preferably a positive number from 4 to 60.
m12 is a positive number of 2 or more, preferably a positive number from 2 to 100, more preferably a positive number from 3 to 80, and even more preferably a positive number from 4 to 60.
The value of m11/m12 is preferably 0.8 to 9, more preferably 2 to 8, and even more preferably 3 to 7.

The average number of (OCF ₂ ) and the average number of (OCF ₂ CF ₂ ) in the fluorine-containing ether compound are measured by ¹⁹ F-NMR.

The fluoropolyether chain in the fluorine-containing ether compound may contain oxyfluoroalkylene units other than (OCF ₂ ) and (OCF ₂ CF ₂ ) (hereinafter also referred to as "other oxyfluoroalkylene units").
Other specific examples of oxyfluoroalkylene units include (OG ^f1 ) _m1 , (OG ^f2 ) _m2 , (OG ^f3 ) _m3 , (OG ^f4 ) _m4 , (OG ^f5 ) _m5 , and (OG ^f6 ) _m6 .
Here, G ^f1 is a fluoroalkylene group having 1 carbon atom (excluding the case where G ^f1 is —CF ₂ —).
G ^f2 is a fluoroalkylene group having 2 carbon atoms (excluding the case where G ^f2 is —CF ₂ CF ₂ —).
G ^f3 is a fluoroalkylene group having 3 carbon atoms,
G ^f4 is a fluoroalkylene group having 4 carbon atoms,
G ^f5 is a fluoroalkylene group having 5 carbon atoms,
G ^f6 is a fluoroalkylene group having 6 carbon atoms,
m1, m2, m3, m4, m5, and m6 each independently represent an integer of 0 or 1 or more.
When the fluoropolyether chain has at least one unit selected from (OG ^f1 ) to (OG ^f6 ), the bonding order of (OG ^f1 ) to (OG ^f6 ) is arbitrary. m1 to m6 represent the average number of (OG ^f1 ) to (OG ^f6 ), respectively, and do not represent the arrangement. For example, (OG ^f5 ) _m5 represents that the average number of (OG ^f5 ) units is m5, and does not represent a block arrangement structure of (OG ^f5 ) _m5 . Similarly, the order of (OG ^f1 ) to (OG ^f6 ) does not represent the bonding order of the respective units.
The fluoroalkylene group having 3 to 6 carbon atoms may be a straight-chain fluoroalkylene group, or may be a fluoroalkylene group having a branched or cyclic structure.

A specific example of ^Gf1 is -CHF-.
Specific examples of G ^f2 include —CHFCF ₂ —, —CHFCHF—, —CH ₂ CF ₂ —, —CH ₂ CHF—, and the like.
Specific examples of G ^f3 include -CF ₂ CF ₂ CF ₂ -, -CF ₂ CHFCF ₂ -, -CF ₂ CH ₂ CF ₂ -, -CHFCF ₂ CF ₂ -, -CHFCHFCF ₂ -, -CHFCHFCHF-, -CHFCH ₂ CF ₂ -, -CH ₂ CF ₂ CF ₂ -, -CH ₂ CHFCF ₂ -, -CH ₂ CH ₂ CF ₂ -, -CH ₂ CF ₂ CHF-, -CH ₂ CHFCHF-, -CH ₂ CH ₂ CHF-, -CF(CF ₃ )-CF ₂ -, -CF( _CHF2 ) _-CF2- , -CF( _CH2F ) _-CF2 -, -CF(CH ₃ )-CF ₂ -, -CF(CF ₃ )-CHF-, -CF(CHF ₂ )-CHF-, -CF(CH ₂ F)-CHF-, -CF(CH ₃ )-CHF-, -CF(CF ₃ )-CH ₂ -, -CF(CHF ₂ )-CH ₂ -, -CF(CH ₂ F)-CH ₂ -, -CF(CH ₃ )-CH ₂ -, -CH(CF ₃ )-CF ₂ -, -CH(CHF ₂ )-CF ₂ -, -CH(CH ₂ F)-CF ₂ -, -CH(CH ₃ )-CF ₂ -, -CH(CF ₃ )-CHF-, -CH(CHF ₂ )-CHF-, -CH(CH ₂ F)-CHF-, -CH(CH ₃ )-CHF-, -CH(CF ₃ )-CH ₂ -, -CH(CHF ₂ )-CH ₂ -, -CH(CH ₂ F)-CH ₂ - and the like.
Specific examples of G ^f4 include -CF ₂ CF ₂ CF ₂ CF ₂ -, -CHFCF ₂ CF ₂ CF ₂ -, -CH ₂ CF ₂ CF ₂ CF ₂ -, -CF ₂ CHFCF ₂ CF ₂ -, -CHFCHF ₂ CF ₂ -, -CH ₂ CHFCF ₂ CF ₂ -, -CF ₂ CH ₂ CF ₂ CF ₂ -, -CHFCH ₂ CF ₂ CF ₂ -, -CH ₂ CH ₂ CF ₂ CF ₂ -, -CHFCF ₂ CHFCF ₂ -, -CH ₂ CF ₂ CHFCF ₂ -, -CF ₂ CHFCHF ₂ -, -CHFCHFCHFCF ₂ -, -CH ₂ CHFCHF ₂ -, -CF ₂ CH ₂ CHFCF ₂ -, -CHFCH ₂ CHFCF ₂ -, -CH ₂ CH ₂ CHFCF ₂ -, -CF ₂ CH ₂ CH ₂ Examples include CF ₂ -, -CHFCH ₂ CH ₂ CF ₂ -, -CH ₂ CH ₂ CH ₂ CF ₂ -, -CHFCH ₂ CH ₂ CHF-, -CH ₂ CH ₂ CH ₂ CHF-, -cycloC ₄ F ₆ -, and the like.
Specific examples of G ^f5 include -CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ -, -CHFCF ₂ CF ₂ CF ₂ CF ₂ -, -CH ₂ CHFCF ₂ CF ₂ CF ₂ -, -CF ₂ CHFCF ₂ CF ₂ CF _{2 - , -CHFCHFCF2CF2CF2- , -CF2CH2CF2CF2CF2- , -CHFCH2CF2CF2CF2- , -CH2CH2CF2CF2CF2- , -CF2CF ​ ​ ​ ​ ​ ​ ​ 2} CHFCF ₂ CF ₂ -, -CHFCF ₂ Examples thereof include CHFCF ₂ CF ₂ -, -CH ₂ CF ₂ CHFCF ₂ CF ₂ -, -CH ₂ CF ₂ CF ₂ CF ₂ CH ₂ -, -cycloC ₅ F ₈ -, and the like.
_{Specific examples of} ^Gf6 _{include -CF2CF2CF2CF2CF2CF2CF2CF2- , -CF2CF2CHFCHFCF2CF2- , -CHFCF2CF2CF2CF2CF2CF2CF2- , -CHFCHFCHFCHFCHFCHFCHF- , -CHFCF2CF2CF2CF2CF2CH2- , -CH2CF2CF2CF2CF2CF2CH2- , -cycloC6F10- , and the like . ​ ​ ​ ​ ​ ​}
Here, -cycloC ₄ F ₆ - means a perfluorocyclobutanediyl group, specific examples of which include a perfluorocyclobutane-1,2-diyl group and a perfluorocyclobutane-1,3-diyl group. -cycloC ₅ F ₈ - means a perfluorocyclopentanediyl group, specific examples of which include a perfluorocyclopentane-1,3-diyl group. -cycloC ₆ F ₁₀ - means a perfluorocyclohexanediyl group, specific examples of which include a perfluorocyclohexane-1,4-diyl group.

The proportion of fluorine atoms in the fluoropolyether chain [{number of fluorine atoms/(number of fluorine atoms+number of hydrogen atoms)}×100(%)] is preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more, from the viewpoint of excellent water and oil repellency and fingerprint removability.
The molecular weight of the fluoropolyether chain portion is preferably from 2,000 to 20,000, more preferably from 2,500 to 15,000, and even more preferably from 3,000 to 10,000, from the viewpoint of abrasion resistance.

The ratio of the total number of other oxyfluoroalkylene units to the total number of all units constituting the fluoropolyether chain is preferably 10% or less, and more preferably 5% or less.

The reactive silyl group is preferably the group (g1).
-SiR ^a1 _z1 R ^a2 _3-z1 ...(g1)
however,
R ^a1 represents a hydroxyl group or a hydrolyzable group, and when there are a plurality of R ^a1 's, the plurality of R ^a1 's may be the same or different from each other;
R ^a2 represents a non-hydrolyzable group, and when there are a plurality of R ^a2 's, the plurality of R ^a2 's may be the same or different from each other;
z1 is an integer of 1 to 3.

When R ^a1 is a hydroxyl group, it forms a silanol (Si—OH) group together with the Si atom. Furthermore, the hydrolyzable group is a group that becomes a hydroxyl group (i.e., a silanol group) through a hydrolysis reaction. The silanol group further reacts with other molecules to form a Si—O—Si bond. Furthermore, the silanol group undergoes a dehydration condensation reaction with a hydroxyl group (substrate (or underlayer)-OH) on the surface of the substrate (or underlayer) to form a chemical bond (substrate (or underlayer)-O—Si). By having one or more groups (g1), the fluorine-containing ether compound has excellent abrasion resistance after the formation of the surface layer.

Examples of the hydrolyzable group for R ^a1 include an alkoxy group, an aryloxy group, a halogen atom, an acyl group, an acyloxy group, and an isocyanate group (-NCO). The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms. The acyl group is preferably an acyl group having 1 to 6 carbon atoms. The acyloxy group is preferably an acyloxy group having 1 to 6 carbon atoms.

From the viewpoint of ease of production of the fluorinated ether compound, R ^a1 is preferably an alkoxy group having 1 to 4 carbon atoms or a halogen atom. The alkoxy group in ^{R a1} is preferably an alkoxy group having 1 to 4 carbon atoms from the viewpoint of excellent storage stability of the fluorinated ether compound and suppression of outgassing during the reaction, more preferably an ethoxy group from the viewpoint of long-term storage stability, and more preferably a methoxy group from the viewpoint of shortening the hydrolysis reaction time. Of these, a chlorine atom is preferred as the halogen atom.

Examples of the non-hydrolyzable group for R ^a2 include a hydrogen atom and a monovalent hydrocarbon group. Examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an alkenyl group, and an allyl group. From the viewpoint of ease of production, an alkyl group is preferred. From the viewpoint of ease of production, the number of carbon atoms in the hydrocarbon group is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2.

z1 may be an integer of 1 to 3, and is preferably 2 or 3, more preferably 3, from the viewpoint of adhesion to the substrate (or undercoat layer).
Specific examples of _{the group (g1) include -Si(OCH3)3, -SiCH3(OCH3)2, -Si(OCH2CH3)3 , -SiCl3 , -Si ( OCOCH3 ) 3 , and} -Si(NCO) ₃ . From the viewpoint of ease of handling in production, -Si( _OCH3 ) ₃ is preferred.
When there are a plurality of groups (g1) in one molecule, the plurality of groups (g1) may be the same or different.

In the fluorine-containing ether compound, the fluoropolyether chain and the group (g1) are bonded directly or via a linking group, which may be a divalent or higher organic group.
The number of fluoropolyether chains in one molecule of the fluorinated ether compound may be 1 or 2 or more. From the viewpoint of ease of synthesis, the number of fluoropolyether chains in one molecule is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 4.
The number of groups (g1) in one molecule of the fluorinated ether compound may be 1 or 2 or more. From the viewpoint of achieving both abrasion resistance and water and oil repellency, the number of groups (g1) is preferably 1 to 32, more preferably 1 to 18, and even more preferably 2 to 12.
When there are a plurality of fluoropolyether chains, the plurality of fluoropolyether chains may be the same or different, and when there are a plurality of groups (g1), the plurality of groups (g1) may be the same or different.

The content of the fluorine-containing ether compound is preferably 0.01 to 100% by mass, more preferably 0.10 to 99.99% by mass, and even more preferably 1.00 to 99.00% by mass, relative to the total mass of the surface treatment agent. When the content of the fluorine-containing ether compound is within the above range, the surface layer will have better water and oil repellency, abrasion resistance, fingerprint stain removability, lubricity, and appearance.

The fluorine-containing ether compound may be any compound as long as it satisfies the above-mentioned constitution. In terms of ease of synthesis, ease of handling of the compound, etc., it is particularly preferred to be a compound represented by the following formula (1-1), (1-2), or (1-3):
[R ^f1 -(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 -O-R ¹ ] _j -L ¹ -(R ¹¹ -T ¹¹ ) _x1 ...(1-1)
(T ³¹ -R ³¹ ) _x3 -L ³ -R ³ -(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 -O-R ² -L ² -(R ²¹ -T ²¹ ) _x2 ...(1-2)
Q ¹ [-(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 -O-R ⁴ -L ⁴ -(R ⁴¹ -T ⁴¹ ) _x4 ] _r1 ...(1-3)
however,
R ^f1 is a fluoroalkyl group having 1 to 20 carbon atoms, and when there are a plurality of R ^f1s , the plurality of R ^f1s may be the same or different from each other,
(OCF ₂ ) _m11 ·(OCF ₂ CF ₂ ) _m12 are as defined above,
R ¹ is an alkylene group or a fluoroalkylene group, and when there are a plurality of R ^1s , the plurality of R ^1s may be the same or different (however, when R ¹ is a fluoroalkylene group, R ¹ is a fluoroalkylene group other than —CF ₂ — and —CF ₂ CF ₂ —).
^L1 is a single bond or a j+x monovalent organic group which may have N, O, S, or Si and which may have a branch point, and atoms bonding to ^R1 and ^R11 are each independently N, O, S, Si, a carbon atom constituting a branch point, or a carbon atom having an oxo group (=O);
R ¹¹ is an alkylene group in which the atom bonded to L ¹ may be an ethereal oxygen atom or which may have an ethereal oxygen atom between carbon atoms,
T ¹¹ is —SiR ^a11 _z11 R ^a12 _3-z11 ,
R ^a11 represents a hydroxyl group or a hydrolyzable group, and when there are a plurality of R ^a11 's, the plurality of R ^a11 's may be the same or different from each other;
R ^a12 represents a non-hydrolyzable group, and when there are a plurality of R ^a12 's, the plurality of R ^a12 's may be the same or different from each other,
j is an integer of 1 or greater,
z11 is an integer of 1 to 3,
x1 is an integer of 1 or more,
R ² and R ³ each independently represent an alkylene group or a fluoroalkylene group (provided that when R ¹ is a fluoroalkylene group, R ¹ is a fluoroalkylene group other than —CF ₂ — and —CF ₂ CF ₂ —);
^L2 is a single bond or a (1+x) divalent organic group which may have N, O, S, or Si and which may have a branch point, and atoms bonding to ^R2 and ^R21 are each independently N, O, S, Si, a carbon atom constituting a branch point, or a carbon atom having an oxo group (=O);
^R21 is an alkylene group in which the atom adjacent to ^L2 may be an ethereal oxygen atom or which may have an ethereal oxygen atom between carbon atoms,
^L3 is a single bond or a (1+x) trivalent organic group which may have N, O, S, or Si and which may have a branch point, and atoms bonding to ^R3 and ^R31 are each independently N, O, S, Si, a carbon atom constituting a branch point, or a carbon atom having an oxo group (=O);
R ³¹ is an alkylene group in which the atom adjacent to L ³ may be an ethereal oxygen atom or which may have an ethereal oxygen atom between carbon atoms,
T ²¹ and T ³¹ are each independently —SiR ^a21 _z21 R ^a22 _3-z21 ;
R ^a21 represents a hydroxyl group or a hydrolyzable group, and when there are a plurality of R ^a21 , the plurality of R ^a21 may be the same or different from each other,
R ^a22 represents a non-hydrolyzable group, and when there are a plurality of R ^a22 , the plurality of R ^a22 may be the same or different from each other,
z21 is an integer of 1 to 3,
x2 and x3 each independently represent an integer of 1 or more,
^Q1 is an r1-valent group having a branch point;
R ⁴ 's each independently represent an alkylene group or a fluoroalkylene group (provided that when R ¹ is a fluoroalkylene group, R ¹ is a fluoroalkylene group other than —CF ₂ — and —CF ₂ CF ₂ —);
^L4 is a single bond or a 1+x tetravalent organic group which may have N, O, S, or Si and which may have a branch point, and atoms bonding to ^R4 and ^R41 are each independently N, O, S, Si, a carbon atom constituting a branch point, or a carbon atom having an oxo group (=O);
R ⁴¹ is an alkylene group in which the atom adjacent to L ⁴ may be an ethereal oxygen atom or which may have an ethereal oxygen atom between carbon atoms,
T ⁴¹ is —SiR ^a41 _z41 R ^a42 _3-z41 ,
R ^a41 represents a hydroxyl group or a hydrolyzable group, and when there are a plurality of R ^a41 , the plurality of R ^a41 may be the same or different from each other,
R ^a42 represents a non-hydrolyzable group, and when there are a plurality of R ^a42 , the plurality of R ^a42 may be the same or different from each other,
z41 is an integer of 1 to 3,
x4 is an integer of 1 or greater,
r1 is 3 or 4.
The structure of each compound will be explained below, and symbols having similar structures will be indicated as such and can be read interchangeably for reference as appropriate.

(Compound (1-1))
The compound (1-1) has a structure represented by the following formula (1-1).
[R ^f1 -(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 -O-R ¹ ] _j -L ¹ -(R ¹¹ -T ¹¹ ) _x1 ...(1-1)
However, each symbol in the formula (1-1) is as described above.

R ^f1 is a fluoroalkyl group having 1 to 20 carbon atoms. The fluoroalkyl group may be linear or may have a branched and/or cyclic structure. From the viewpoint of abrasion resistance, a linear fluoroalkyl group is preferred, and from the viewpoint of ease of synthesis, the fluoroalkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.

(OCF ₂ ) _m11 and (OCF ₂ CF ₂ ) _m12 are as described above.

R ¹ is an alkylene group or a fluoroalkylene group, provided that when R ¹ is a fluoroalkylene group, R ¹ is a fluoroalkylene group other than —CF ₂ — and —CF ₂ CF ₂ —.
The alkylene group and fluoroalkylene group in ^R1 may be linear or may have a branched and/or cyclic structure. From the viewpoint of ease of synthesis, linear or branched alkylene groups or fluoroalkylene groups are preferred, and linear or branched alkylene groups or fluoroalkylene groups having a methyl group or a fluoromethyl group are more preferred. The number of carbon atoms in ^R1 is preferably 1 to 6, more preferably 1 to 3. When ^L1 is a single bond, ^R1 is bonded to ^R11 . In this case, the carbon atom bonded to ^R11 in ^R1 is bonded to at least one fluorine atom or fluoroalkyl group.

j represents the number of [R ^f1 -(OCF ₂ ) _m11 ·(OCF ₂ CF ₂ ) _m12 -O—R ¹ ] in one molecule, and may be an integer of 1 or more, preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 4.

R ¹¹ is an alkylene group in which the atom bonded to L ¹ may be an ethereal oxygen atom or which may have an ethereal oxygen atom between carbon atoms.
The alkylene group for R ¹¹ may be linear or may have a branched and/or cyclic structure. In view of the ease with which the present surface treatment agent is densely arranged when forming a surface layer, an alkylene group having a methyl group as a linear or branched chain is preferred, and a linear alkylene group is more preferred.
Specifically, R ¹¹ can be represented by the following formula (g2).
*-(O) _a1 -(R ^g2 O) _a2 -R ^g2 -** ...(g2)
however,
R ^g2 is an alkylene group having 1 or more carbon atoms, and a plurality of R ^g2 may be the same or different from each other.
a1 is 0 or 1,
a2 is an integer of 0 or more,
* is a bond bonded to ^L1 ,
** is a bond bonded to ^T11 .

When a1 is 0, the atom having the bond * is a carbon atom, and when a1 is 1, the atom having the bond * is an oxygen atom. In compound (1-1), a1 may be either 0 or 1, and may be appropriately selected from the viewpoint of synthesis, etc.
a2 is the number of repetitions of R ^g2 O, and is preferably 0 to 6, more preferably 0 to 3, and even more preferably 0 to 1, from the viewpoint of durability as a surface layer.

R ¹¹ is more preferably a group represented by the following formula (g3) in that the surface layer has better water and oil repellency, better fingerprint stain removability, and better durability such as abrasion resistance.
*-(O) _a1 -R ^g3 -** ...(g3)
however,
R ^g3 is an alkylene group;
a1, *, and ** are the same as in formula (g2).

The alkylene group for R ^g3 may be linear or may have a branched and/or cyclic structure, and is preferably a linear alkylene group because the compound (1-1) is likely to be densely arranged when forming a surface layer.

T ¹¹ is —SiR ^a11 _z11 R ^a12 _3-z11 , and R ^a11 , R ^a12 and z11 are the same as R ^a1 , R ^a2 and z1 constituting the group (g1), respectively, and preferred embodiments are also the same.

x1 represents the number of —R ¹¹ -T ¹¹ in one molecule, and may be an integer of 1 or more, preferably 1 to 32, more preferably 1 to 18, and even more preferably 2 to 12.

^L1 is a single bond or a j+x monovalent group which may have N, O, S, or Si and which may have a branch point, and the atoms bonding to ^R1 and ^R11 are each independently N, O, S, Si, a carbon atom constituting a branch point, or a carbon atom having an oxo group (=O). The atoms bonding to ^R1 and ^R11 may be the same atom or different atoms.

When L ¹ is a single bond, R ¹ and R ¹¹ in formula (1-1) are directly bonded, and compound (1-1) is represented by the following formula (1-1′).
R ^f1 -(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 -O-R ¹ -R ¹¹ -T ¹¹ ...(1-1')
However, each symbol in the formula (1-1') is the same as in the formula (1-1).

When ^L1 is a trivalent or higher valent group, ^L1 has at least one branch point (hereinafter also referred to as "branch point ^P1 ") selected from the group consisting of C, N, Si, a ring structure, and a (j+x1)-valent organopolysiloxane residue.

When N is the branch point ^P1 , the branch point ^P1 is represented by, for example, *-N(-**) ₂ or (*-) _2N -**, where * is a bond on the ^R1 side and ** is a bond on the ^R11 side.
When C is the branch point ^P1 , the branch point ^P1 is represented by, for example, *-C(-**) ₃ , (*-) ₂ C(-**) ₂ , (*-) ₃ C-**, *-CR ²⁹ (-**) ₂ , or (*-) ₂ CR ²⁹ -**, where * is a bond on the R ¹ side, ** is a bond on the R ¹¹ side, and R ²⁹ is a monovalent group such as a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group.
When Si is the branch point ^P1 , the branch point ^P1 is represented, for example, by *-Si(-**) ₃ , (*-) ₂ Si(-**) ₂ , (*-) ₃ Si-**, *-SiR ²⁹ (-**) ₂ , or (*-) ₂ SiR ²⁹ -**, where * represents a bond on the R ¹ side, ** represents a bond on the R ¹¹ side, and R ²⁹ represents a monovalent group such as a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group.

As the ring structure constituting branch point ^P1 , from the viewpoints of ease of production of compound (1-1) and of further improving the abrasion resistance, light resistance, and chemical resistance of the surface layer, one type selected from the group consisting of a 3- to 8-membered aliphatic ring, a 3- to 8-membered aromatic ring, a 3- to 8-membered heterocycle, and a fused ring consisting of two or more of these rings is preferred, and a ring structure shown in the following formula is more preferred. The ring structure may have a substituent such as a halogen atom, an alkyl group (which may contain an ethereal oxygen atom between the carbon atoms), a cycloalkyl group, an alkenyl group, an allyl group, an alkoxy group, or an oxo group (═O).

Examples of organopolysiloxane residues constituting branch point ^P1 include the following groups: In the following formula, ^R25 is a hydrogen atom, an alkyl group, an alkoxy group, or a phenyl group. The alkyl group and alkoxy group of ^R25 preferably have 1 to 10 carbon atoms, and more preferably 1 carbon atom.

The divalent or higher valent L ¹ is at least one bond selected from the group consisting of —C(O)N(R ²⁶ )—, —N(R ²⁶ )C(O)—, —C(O)O—, —OC(O)—, —C(O)—, —O—, —N(R ²⁶ )—, —S—, —OC(O)O—, —NHC(O)O—, —OC(O)NH—, —NHC(O)N(R ²⁶ )—, —SO ₂ N(R ²⁶ )—, —N(R ²⁶ )SO ₂ —, —Si(R ²⁶ ) ₂ —, —OSi(R ²⁶ ) ₂ —, —Si(CH ₃ ) ₂ —Ph-Si(CH ₃ ) ₂ —, and a divalent organopolysiloxane residue (hereinafter referred to as “bond B ¹ ").
wherein R ²⁶ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group, and Ph is a phenylene group. The number of carbon atoms in the alkyl group of ^{R 26} is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2, from the viewpoint of ease of production of compound (1-1).

Examples of divalent organopolysiloxane residues include groups represented by the following formula: In the formula, R ²⁷ represents a hydrogen atom, an alkyl group, an alkoxy group, or a phenyl group. The alkyl group and alkoxy group represented by R ²⁷ preferably have 1 to 10 carbon atoms, and more preferably 1.

As the bond ^B1 , from the viewpoint of ease of production of compound (1-1), at least one bond selected from the group consisting of —C(O)NR ²⁶ —, —N(R ²⁶ )C(O)—, —C(O)—, and —NR ²⁶ — is preferred, and from the viewpoint of further improving the light resistance and chemical resistance of the surface layer, —C(O)NR ²⁶ —, —N(R ²⁶ )C(O)—, or —C(O)— is more preferred.

In the divalent ^L1 , the atoms bonded to ^R1 and ^R11 are each independently N, O, S, Si, or a carbon atom having an oxo group (=O). That is, the atoms adjacent to ^R1 and ^R11 are each constituent elements of the bond ^B1 . Specific examples of the divalent ^L1 include a single bond and one or more bonds ^B1 (for example, * ^-B1 -**, * ^-B1 - ^R28 - ^B1 -**). However, ^R28 is a single bond or a divalent organic group, * is a bond on the ^R1 side, and ** is a bond on the ^R11 side.

In the trivalent or higher ^{valent L1} , the atoms bonded to ^R1 and ^R11 are each independently N, O, S, Si, a carbon atom constituting a branch point, or a carbon atom having an oxo group (═O). That is, the atoms adjacent to ^R1 and ^R11 are each a constituent element of the bond ^B1 or the branch point ^P1 . Specific examples of trivalent or higher valent L ¹ include one or more branch points P ¹ (for example, {(*-) _j P ¹ (-**) _x1 }, {(*-) _j P ¹ -R ²⁸ -P ¹ (-**) _x1 }, etc.), and combinations of one or more branch points P ¹ and one or more bonds B ¹ (for example, {*-B ¹ -R ²⁸ -P ¹ (-**) _x1 }, {*-B ¹ -R ²⁸ -P ¹ (-R ²⁸ -B ¹ -**) _x1 }, etc., where R ²⁸ is a single bond or a divalent organic group, * is a bond on the R ¹ side, and ** is a bond on the R ¹¹ side.

Examples of the divalent organic group for R ²⁸ include hydrocarbon groups such as divalent aliphatic hydrocarbon groups (such as alkylene groups and cycloalkylene groups) and divalent aromatic hydrocarbon groups (such as phenylene groups), and the hydrocarbon groups may have a bond ^B1 between carbon atoms. The divalent organic group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.

As the above ^L1 , a group represented by any one of the following formulae (L1) to (L7) is preferred in terms of ease of production of the compound (1-1).

(-A ¹ -) _d5 C(R ^e2 ) _4-d5-d6 (-Q ²² -) _d6 ...(L2)
(-A ² -) _d7 N (-Q ²³ -) _3-d7 ...(L3)
(-A ³ -) _d8 Z ¹ (-Q ²⁴ -) _d9 ...(L4)
(-A ² -) _d10 Si(R ^e3 ) _4-d10-d11 (-Q ²⁵ -) _d11 ...(L5)
-A ¹ -Q ²⁶ - ... (L6)
-A ¹ -CH(-Q ²² -)-Si(R ^e3 ) _3-d12 (-Q ²⁵ -) _d12 ...(L7)

In formula (L1) to formula (L7), A ¹ , A ² or A ³ side is connected to R ¹ in formula (1-1), and Q ²² , Q ²³ , Q ²⁴ , Q ²⁵ or Q ²⁶ side is connected to R ¹¹ .
wherein A ¹ is a single bond, -B ³ -, -B ³ -R ³⁰ -, or -B ³ -R ³⁰ -B ² -, R ³⁰ is an alkylene group or a group having -C(O)NR ^e6 -, -C(O)-, -NR ^e6 -, or -O- between carbon atoms in an alkylene group having 2 or more carbon atoms, B ² is -C(O)NR ^e6 -, -C(O)-, -NR ^e6 -, or -O-, and B ³ is -C(O)NR ^e6 -, -C(O)-, or -NR ^e6 -;
A ² is a single bond or —B ³ —R ³⁰ —;
^A3 is ^A1 when the atom in ^Z1 to which ^A3 is bonded is a carbon atom, and ^A2 when the atom in ^Z1 to which ^A3 is bonded is a nitrogen atom;
Q ¹¹ is a single bond, —O—, an alkylene group, or an alkylene group having 2 or more carbon atoms and having —C(O)NR ^e6 —, —C(O)—, —NR ^e6 — or —O— between carbon atoms;
Q ²² is a single bond, —B ³ —, —R ³⁰ —B ³ — or —B ² —R ³⁰ —B ³ —;
Q ²³ is a single bond or —R ³⁰ —B ³ —;
Q ²⁴ is Q ²² when the atom in Z ¹ to which Q ²⁴ is bonded is a carbon atom, and Q ²³ when the atom in Z ¹ to which Q ²⁴ is bonded is a nitrogen atom;
Q ²⁵ is a single bond or —R ³⁰ —B ³ —;
Q ²⁶ is a single bond or —R ³⁰ —B ³ —;
^Z1 is a group having a (d8+d9)-valent ring structure having a carbon atom or nitrogen atom to which ^A3 is directly bonded and a carbon atom or nitrogen atom to which ^Q24 is directly bonded,
R ^e1 is a hydrogen atom or an alkyl group,
R ^e2 is a hydrogen atom, a hydroxyl group, an alkyl group, or an acyloxy group;
R ^e3 is an alkyl group;
R ^e6 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group;
d1 is an integer of 0 to 3, d2 is an integer of 0 to 3, and d1+d2 is an integer of 1 to 3;
d3 is an integer of 0 to 3, d4 is an integer of 0 to 3, and d3+d4 is an integer of 1 to 3;
d1+d3 is an integer from 1 to 5,
d2+d4 is an integer from 1 to 5,
d5 is an integer of 1 to 3, d6 is an integer of 1 to 3, and d5+d6 is an integer of 2 to 4;
d7 is 1 or 2,
d8 is an integer of 1 or more,
d9 is an integer of 1 or more,
d10 is an integer of 1 to 3, d11 is an integer of 1 to 3, and d10+d11 is an integer of 2 to 4;
d12 is an integer of 1 to 3.
When there are a plurality of A ¹ 's, the A ¹ 's may be the same or different from one another. The same applies to ^{A 2} , A ³ , Q ²² , Q ²³ , Q ²⁴ , Q ²⁵ , R ^e1 , R ^e2 , and R ^e3 .
Also, d1+d3, d5, d7, d8, and d10 are j, and d2+d4, d6, 3-d7, d9, d11, and 1+d12 are x1.

The number of carbon atoms in the alkylene group of R ³⁰ is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4, from the viewpoints of ease of production of compound (1-1) and further excellent abrasion resistance, light resistance, and chemical resistance of the surface layer. However, when a specific bond is present between carbon atoms, the lower limit of the number of carbon atoms in the alkylene group is 2.
Examples of the ring structure in ^Z1 include the ring structures described above, and the preferred embodiments are also the same.

The alkyl group of R ^e1 , R ^e2 or R ^e3 preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms, in view of ease of production of the compound (1-1).
The number of carbon atoms in the alkyl group moiety of the acyloxy group of R ^e2 is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2, from the viewpoint of ease of production of the compound (1-1).
d9 is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3, from the viewpoint of ease of production of compound (1-1) and further excellent abrasion resistance and fingerprint stain removability of the surface layer.

Other examples of ^L1 include groups represented by any of the following formulae (L11) to (L17).

(-A ¹ -) _d5 C(R ^e2 ) _4-d5-d6 (-Q ²² -G) _d6 ...(L12)
(-A ² -) _d7 N (-Q ²³ -G) _3-d7 ...(L13)
(-A ³ -) _d8 Z ¹ (-Q ²⁴ -G) _d9 ...(L14)
(-A ² -) _d10 Si(R ^e3 ) _4-d10-d11 (-Q ²⁵ -G) _d11 ...(L15)
-A ¹ -Q ²⁶ -G...(L16)
-A ¹ -CH(-Q ²² -)-Si(R ^e3 ) _3-d12 (-Q ²⁵ -G) _d12 ...(L17)

In formulas (L11) to (L17), A ¹ , A ² or A ³ is connected to R ¹ in formula (1-1), and Q ²² , Q ²³ , Q ²⁴ , Q ²⁵ or Q ²⁶ is connected to R ^11. G is the following group (G21), and two or more Gs in L ¹ may be the same or different. The symbols other than G are the same as the symbols in formulas (L1) to (L7).
-Si(R ²¹ ) _3-k (-Q ³ -) _k ...(G21)
In formula (G21), the Si side is connected to Q ²² , Q ²³ , Q ²⁴ , Q ²⁵ or Q ²⁶ , and the Q ³ side is connected to R ^11. R ²¹ is an alkyl group. Q ³ is a single bond or -R ³¹ -B ³ -, where R ³¹ is an alkylene group, or a group having -C(O)NR ³² -, -C(O)-, -NR ³² - or -O- between carbon atoms in an alkylene group having 2 or more carbon atoms, or -(OSi(R ²² ) ₂ ) _p11 -O-, and two or more Q ^3s may be the same or different. k is 2 or 3. ^{R 32} is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group. R ²² is an alkyl group, a phenyl group or an alkoxy group, and two R ^22s may be the same or different. p11 is an integer of 0 to 5, and when p11 is 2 or more, the two or more (OSi(R ²² ) ₂ ) groups may be the same or different.

The number of carbon atoms in the alkylene group of ^Q3 is preferably 1 to 10, more preferably 1 to 6, and still more preferably 1 to 4, from the viewpoints of ease of production of compound (1-1) and further improved abrasion resistance, light resistance, and chemical resistance of the surface layer. However, when a specific bond is present between carbon atoms, the lower limit of the number of carbon atoms in the alkylene group is 2.
The number of carbon atoms in the alkyl group of R ²¹ is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2, in terms of ease of production of the compound (1-1).
The number of carbon atoms in the alkyl group of R ²² is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2, in terms of ease of production of the compound (1-1).
The number of carbon atoms in the alkoxy group of R ²² is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2, in view of excellent storage stability of the compound (1-1).
p11 is preferably 0 or 1.

Examples of the compound (1-1) include the following: wherein R ^f is [R ^f1 -(OCF ₂ ) _m11 ·(OCF ₂ CF ₂ ) _m12 -O—R ¹ ].

(Compound (1-2))
The compound (1-2) has a structure represented by the following formula (1-2).
(T ³¹ -R ³¹ ) _x3 -L ³ -R ³ -(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 -O-R ² -L ² -(R ²¹ -T ²¹ ) _x2 ...(1-2)
However, each symbol in the formula (1-2) is as described above.

(OCF ₂ ) _m11 and (OCF ₂ CF ₂ ) _m12 are as described above.

^R2 and ^R3 are each independently the same as ^R1 above, and preferred embodiments are also the same.

^R21 and ^R31 are the same as ^R11 above, and preferred embodiments are also the same. However, "bonded to ^L1 " is to be read as "bonded to ^L2 " in the case of ^R21 , and as "bonded to ^L3 " in the case of ^R31 . Furthermore, "bonded to ^T11 " is to be read as "bonded to ^T21 " in the case of ^R21 , and as "bonded to ^T31 " in the case of ^R31 . When ^L2 is a single bond, ^R21 is directly bonded to ^R2 . When ^L3 is a single bond, ^R31 is directly bonded to ^R3 .

T ²¹ and T ³¹ are each independently —SiR ^a21 _z21 R ^a22 _3-z21 , and R ^a21 , R ^a22 , and z21 are the same as R ^a1 , R ^a2 , and z1 constituting the group (g1), respectively, and preferred embodiments are also the same.

x2 and x3 each independently represent the same as x1, and the preferred embodiments are also the same.

^L2 and ^L3 each independently represent the same as ^L1 when j is 1.
For example, when L ² and L ³ are single bonds, the compound (1-2) is represented by the following formula (1-2′).
T ³¹ -R ³¹ -R ³ -(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 -O-R ² -L ² -R ²¹ -T ²¹ ...(1-2')
However, the symbols in formula (1-2') are the same as those in formula (1-2).

When ^L2 or ^L3 is a trivalent or higher valent group, ^L2 or ^L3 has at least one branch point (hereinafter also referred to as "branch point ^P2 ") selected from the group consisting of C, N, Si, a ring structure, and a (1+x2)- or (1+x3)-valent organopolysiloxane residue.

When N is the branch point ^P2 , the branch point ^P2 is represented, for example, by *-N(-**) ₂ , where * is a bond on the ^R2 or ^R3 side, and ** is a bond on the ^R21 or ^R31 side.
When C is the branch point ^P2 , the branch point ^P2 is represented, for example, by *-C(-**) ₃ or *-CR ²⁹ (-**) _2. In this regard, * represents a bond on the R ² or R ³ side, ** represents a bond on the R ²¹ or R ³¹ side, and R ²⁹ represents a monovalent group such as a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group.
When Si is the branch point ^P2 , the branch point ^P2 is represented, for example, by *-Si(-**) ₃ or *-SiR ²⁹ (-**) _2. In this regard, * represents a bond on the R ² or R ³ side, ** represents a bond on the R ²¹ or R ³¹ side, and R ²⁹ represents a monovalent group such as a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group.

The ring structure and organopolysiloxane residue constituting branch point ^P2 are the same as those for branch point ^P1 , and preferred embodiments are also the same.
Furthermore, ^L2 or ^L3 which is divalent or more may each independently have the bond ^B1 . The embodiments of the bond ^B1 are as described above, and the preferred embodiments are also the same.

In divalent ^L2 or ^L3 , the atoms bonding to ^R2 and ^R21 , or ^R3 and ^R31 , are each independently N, O, S, Si, or a carbon atom having an oxo group (=O). That is, the atoms adjacent to ^R2 and ^R21 , or ^R3 and ^R31 , are each constituent elements of bond ^B1 . Specific examples of divalent ^L2 or ^L3 include a single bond and one or more bonds ^B1 (for example, * ^-B1 -**, * ^-B1 - ^R28 - ^B1 -**). However, ^R28 is a single bond or a divalent organic group, * is a bond on the ^R2 or ^R3 side, and ** is a bond on the ^R21 or ^R31 side.

In trivalent or higher valent ^L2 or ^L3 , the atoms bonded to ^R2 and ^R21 , or ^R3 and ^R31 , are each independently N, O, S, Si, a carbon atom constituting a branch point, or a carbon atom having an oxo group (=O). That is, the atoms adjacent to ^R2 and ^R21 , or ^R3 and ^R31 , are each a constituent element of bond ^B1 or branch point ^P2 . Specific examples of trivalent or higher ^L2 or ^L3 include one or more branch points ^P2 (for example ^{, {*-P2(-**)x}, {*-P1-R28-P1 -} _** ^{x1 ,} _etc. ), and combinations of one or more branch points ^P2 and one or more bonds ^B1 (for example, {* ^-B1 - ^R28 - ^P1 (-**) _x }, {* ^-B1 - ^R28 - ^P1 ( ^-R28 - ^B1 -**) _x }, etc., where x is x2 in the case of ^L2 and x3 in the case of ^L3 . ^R28 is a single bond or a divalent organic group, * is a bond on the ^R2 or ^R3 side, and ** is a bond on the ^R21 or ^R31 side.
The embodiments of R ²⁸ are as described above, and the preferred embodiments are also the same.

As the above ^L2 or ^L3 , it is preferable that each independently be a group represented by any one of the following formulae (L21) to (L27), in view of ease of production of the compound (1-2).

-A ¹ -C(R ^e2 ) _4-d6 (-Q ²² -) _d6 ...(L22)
-A ² -N(-Q ²³ -) ₂ ...(L23)
-A ³ -Z ¹ (-Q ²⁴ -) _d9 ...(L24)
-A ² -Si(R ^e3 ) _4-d11 (-Q ²⁵ -) _d11 ...(L25)
-A ¹ -Q ²⁶ - ... (L26)
-A ¹ -CH(-Q ²² -)-Si(R ^e3 ) _3-d12 (-Q ²⁵ -) _d12 ...(L27)

In formula (L21) to formula (L27), A ¹ , A ² or A ³ side is connected to R ² or R ³ , and Q ²² , Q ²³ , Q ²⁴ , Q ²⁵ or Q ²⁶ side is connected to R ²¹ or R ³¹ .
Here, A ¹ , A ² , A ³ , Q ¹¹ , Q ²² , Q ²³ , Q ²⁴ , Q ²⁵ , Q ²⁶ , R ^e1 , R ^e2 , R ^e3 , and R ^e6 are the same as those explained in L ¹ above, and preferred embodiments are also the same.
^Z1 is a group having a (1+d9)-valent ring structure having a carbon atom or nitrogen atom to which ^A3 is directly bonded and a carbon atom or nitrogen atom to which ^Q24 is directly bonded,
d2 is an integer of 0 to 3, d4 is an integer of 0 to 3, and d2+d4 is an integer of 1 to 5;
d6 is an integer between 1 and 3,
d9 is an integer of 1 or more,
d11 is an integer of 1 to 3, and d12 is an integer of 1 to 3.
Note that d2+d4, d6, d9, d11, and 1+d12 are x2 or x3.
d9 is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3, from the viewpoint of ease of production of compound (1-2) and further excellent abrasion resistance and fingerprint stain removability of the surface layer.

Other examples of ^L2 or ^L3 include groups represented by any of the following formulae (L31) to (L37).

-A ¹ -C(R ^e2 ) _4-d6 (-Q ²² -G) _d6 ...(L32)
-A ² -N(-Q ²³ -G) ₂ ...(L33)
-A ³ -Z ¹ (-Q ²⁴ -G) _d9 ...(L34)
-A ² -Si(R ^e3 ) _4-d11 (-Q ²⁵ -G) _d11 ...(L35)
-A ¹ -Q ²⁶ -G...(L36)
-A ¹ -CH(-Q ²² -)-Si(R ^e3 ) _3-d12 (-Q ²⁵ -G) _d12 ...(L37)

In formulas (L31) to (L37), A ¹ , A ² or A ³ is connected to R ² or R ³ , and Q ²² , Q ²³ , Q ²⁴ , Q ²⁵ or Q ²⁶ is connected to R ²¹ or R ^31. G is the group (G21) above, and preferred embodiments are also the same. The symbols other than G are the same as the symbols in formulas (L21) to (L27), and preferred embodiments are also the same.

Examples of the compound (1-2) include the following: wherein Q ^f is —R ³ —(OCF ₂ ) _m11 ·(OCF ₂ CF ₂ ) _m12 —O—R ² —.

(Compound (1-3))
The compound (1-3) has a structure represented by the following formula (1-3).
Q ¹ [-(OCF ₂ ) _m11・(OCF ₂ CF ₂ ) _m12 -O-R ⁴ -L ⁴ -(R ⁴¹ -T ⁴¹ ) _x4 ] _r1 ...(1-3)
However, each symbol in the formula (1-3) is as described above.

(OCF ₂ ) _m11 and (OCF ₂ CF ₂ ) _m12 are as described above.

^R4 is the same as ^R1 above, and the preferred embodiments are also the same.

R ⁴¹ is the same as R ¹¹ above, and preferred embodiments are also the same. However, "bonded to L ¹ " should be read as "bonded to L ⁴ ". Furthermore, "bonded to T ¹¹ " should be read as "bonded to T ⁴¹ ". When L ⁴ is a single bond, R ⁴¹ is directly bonded to R ⁴ .

T ⁴¹ is —SiR ^a41 _z41 R ^a42 _3-z41 , and R ^a41 , R ^a42 and z41 are the same as R ^a1 , R ^a2 and z1 constituting the group (g1), respectively, and preferred embodiments are also the same.

x4 is the same as x1, and the preferred embodiments are also the same.
^L4 is the same as ^L2 or ^L3 , and the preferred embodiments are also the same.

Q ¹ is an r1-valent group having a branch point, and r1 is 3 or 4.

Examples of the branch point ^P3 constituting ^Q1 include N, C, Si, or a ring structure. The number of branch points ^P3 may be one or two or more.

When N is the branch point ^P3 , the branch point ^P1 is expressed as N(-*) ₃ , ^NR29 (-*) ₂ , for example.
When C is the branch point ^P3 , examples of the branch point ^P3 include C(-*) ₄ , CR ²⁹ (-*) ₃ , and C(R ²⁹ ) ₂ (-*) ₂ .
When Si is the branch point ^P3 , examples of the branch point ^P3 include Si(-*) ₄ , SiR ²⁹ (-*) ₃ , and Si(R ²⁹ ) ₂ (-*) ₂ .
where * represents a bond on the (OCF ₂ ) _m11 /(OCF ₂ CF ₂ ) _m12 side, and R ²⁹ is a monovalent group. Examples of R ²⁹ include a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a fluoroalkyl group, and a fluoropolyether chain not having R ⁴¹ -T ⁴¹ .

Examples of the ring structure constituting the branch point ^P3 include the same as those constituting the branch point ^P1 , and the ring structure may further have, as a substituent, a fluorine atom, a fluoroalkyl group, or a fluoropolyether chain not having R ⁴¹ -T ⁴¹ , in addition to the above-mentioned substituents.

As the above ^Q1 , a group represented by any one of the following formulae (Q1) to (Q8) is preferred in terms of ease of production of the compound (1-3).

C(-A ¹¹ -) _d23 (R ^e12 ) _4-d23 ...(Q2)
N(-A ^12- ) ₃ ...(Q3)
Z ¹ (-A ¹³ -) _d24 ...(Q4)
Si(-A ¹² -) _d25 (R ^e13 ) _4-d25 ...(Q5)
CH(-A ¹¹ -) ₂ -Si(R ^e13 ) _3-d26 (-A ¹¹ -) _d26 ...(Q6)

However, in the formulae (Q1) to (Q8), A ¹¹ , A ¹² or A ¹³ is connected to (OCF ₂ ) _m11 ·(OCF ₂ CF ₂ ) _m12 .
wherein A ¹¹ is a single bond, —R ⁴⁰ —, or —B ¹³ —R ⁴⁰ —, in which R ⁴⁰ is an alkylene group, a fluoroalkylene group, or a group having —C(O)NR ^e17 —, —C(O)—, —NR ^e17 —, or —O— between carbon atoms in an alkylene group or fluoroalkylene group having 2 or more carbon atoms; and B ¹³ is —C(O)NR ^e6 —, —C(O)—, —NR ^e6 —, or —O—;
A ¹² is a single bond or —R ⁴⁰ —;
A ¹³ is A ¹¹ when the atom in Z ¹ to which A ¹³ is bonded is a carbon atom, and A ¹² when the atom in Z ¹ to which A ¹³ is bonded is a nitrogen atom;
Z ¹ is a group having an r1-valent ring structure containing a carbon atom or nitrogen atom to which A ¹³ is directly bonded,
Q ⁵² is a single bond, —O—, an alkylene group, a fluoroalkylene group, or a group having —C(O)NR ^e17 —, —C(O)—, —NR ^e17 — or —O— between carbon atoms in an alkylene group or fluoroalkylene group having 2 or more carbon atoms;
R ^e11 is a hydrogen atom, a fluorine atom, an alkyl group, a fluoroalkyl group, a fluoropolyether chain not having R ⁴¹ -T ⁴¹ , or a group having a repeating structure of -Q ⁵² -C(R ^e11 ) _3-d21 (-A ¹¹ -) _d21 in which r1 is 3 to 4;
R ^e12 is a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a fluoroalkyl group, or a fluoropolyether chain having no R ⁴¹ -T ⁴¹ ;
R ^e13 is an alkyl group or a fluoroalkyl group,
R ^e14 , R ^e15 , and R ^e16 each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or a fluoroalkyl group;
R ^e17 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group, or a phenyl group which may be substituted with fluorine;
d21 is an integer of 0 to 3, d22 is an integer of 0 to 3, and d21+d22 is an integer of 3 to 4;
d23 is 3 or 4,
d24 is 3 or 4,
d25 is 3 or 4,
d26 is 1 or 2,
d27 is an integer from 1 to 3,
d28 is 1 or 2,
d29 is an integer from 1 to 3,
d30 is an integer from 1 to 3,
d31 is 1 or 2,
d32 is 1 or 2,
d33 is an integer of 1 to 3.
When there are a plurality of A ¹¹ , the plurality of A ¹ may be the same or different from each other. The same applies to ^{A 12} , A ¹³ , R ^e11 , R ^e12 and R ^e13 .

The number of carbon atoms in the alkylene group or fluoroalkylene group for R ⁴⁰ is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4, from the viewpoints of ease of production of compound (1-3) and further excellent abrasion resistance, light resistance, and chemical resistance of the surface layer. However, when a specific bond is present between carbon atoms, the lower limit of the number of carbon atoms in the alkylene group is 2.
Examples of the ring structure in ^Z1 include the ring structures described above, and the preferred embodiments are also the same.

In R ^e11 , R ^e12 , R ^e13 , R ^e14 , R ^e15 and R ^e16 , the number of carbon atoms in the alkyl group or fluoroalkylene group is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2, from the viewpoint of ease of production of compound (1-3).

Examples of the compound (1-3) include the following: wherein R ^f3 is (OCF ₂ ) _m11 ·(OCF ₂ CF ₂ ) _m12 —O—R ⁴ .

<Other ingredients>
The present surface treatment agent may contain at least one of a fluorine-containing compound other than the above-mentioned fluorine-containing ether compound and the following impurities. Examples of the impurities include compounds that are unavoidable in the production of the above-mentioned fluorine-containing ether compound and other fluorine-containing compounds. Note that the present surface treatment agent does not contain a liquid medium described below.

Examples of other fluorine-containing compounds include fluorine-containing compounds produced as by-products in the production process of the above-mentioned fluorine-containing ether compounds (hereinafter also referred to as "by-product fluorine-containing compounds"), and known fluorine-containing compounds used for the same applications as the above-mentioned fluorine-containing ether compounds.
As the other fluorine-containing compound, a compound which is unlikely to deteriorate the properties of the above-mentioned fluorine-containing ether compound is preferred.

By-product fluorine-containing compounds include unreacted fluorine-containing compounds during the synthesis of the above-mentioned fluorine-containing ether compound. When the surface treatment agent contains by-product fluorine-containing compounds, the purification step for removing the by-product fluorine-containing compounds or reducing the amount of the by-product fluorine-containing compounds can be simplified.

Examples of known fluorine-containing compounds include compounds described in the following documents:
perfluoropolyether-modified aminosilanes described in Japanese Patent Laid-Open No. 11-029585;
Silicon-containing organic fluorine-containing polymers described in Japanese Patent No. 2874715;
Organosilicon compounds described in JP-A-2000-144097,
perfluoropolyether-modified aminosilanes described in Japanese Patent Application Laid-Open No. 2000-327772;
Fluorinated siloxanes described in Japanese Patent Publication No. 2002-506887;
Organosilicon compounds described in Japanese Patent Publication No. 2008-534696;
Fluorinated modified hydrogen-containing polymers described in Japanese Patent No. 4138936;
Compounds described in U.S. Patent Application Publication No. 2010/0129672, WO 2014/126064, and JP 2014-070163 A;
Organosilicon compounds described in WO 2011/060047 and WO 2011/059430;
fluorine-containing organosilane compounds described in WO 2012/064649;
Fluorooxyalkylene group-containing polymers described in Japanese Patent Application Laid-Open No. 2012-72272;
fluorine-containing ether compounds described in WO 2013/042732, WO 2013/121984, WO 2013/121985, WO 2013/121986, WO 2014/163004, JP 2014-080473 A, WO 2015/087902, WO 2017/038830, WO 2017/038832, and WO 2017/187775;
perfluoro(poly)ether-containing silane compounds described in JP 2014-218639 A, WO 2017/022437 A, WO 2018/079743 A, and WO 2018/143433 A;
Fluoropolyether group-containing polymer-modified silanes described in Japanese Patent Application Laid-Open No. 2015-199906, Japanese Patent Application Laid-Open No. 2016-204656, Japanese Patent Application Laid-Open No. 2016-210854, and Japanese Patent Application Laid-Open No. 2016-222859 WO 2018/216630, WO 2019/039226, WO 2019/039341, WO 2019/039186, WO 2019/044479, Japanese Patent Application Laid-Open No. 2019-44158, WO 2019/044479, and WO 2019/163282 Fluorine-containing ether compounds described in.
Commercially available fluorine-containing compounds include the KY-100 series (KY-178, KY-185, KY-195, etc.) manufactured by Shin-Etsu Chemical Co., Ltd., the SURECO AF series such as SURECO (registered trademark) 2101S manufactured by AGC Inc., and OPTOOL (registered trademark) DSX, OPTOOL (registered trademark) AES, OPTOOL (registered trademark) UF503, and OPTOOL (registered trademark) UD509 manufactured by Daikin Industries, Ltd.

When the surface treatment agent contains the other fluorine-containing compounds described above, the content of the other fluorine-containing compounds is preferably less than 50% by mass, more preferably less than 30% by mass, and even more preferably less than 10% by mass, relative to the total mass of the surface treatment agent, in order to fully exhibit the properties of the fluorine-containing ether compound.

[Coating liquid]
The coating liquid of the present invention (hereinafter also referred to as "the present coating liquid") contains the present surface treatment agent and a liquid medium. The present coating liquid may be in any liquid form, and may be a solution or a dispersion.
The present coating liquid is only required to contain the present surface treatment agent, and may contain impurities such as by-products produced in the production process of the fluorinated ether compound.

The content of the surface treatment agent is preferably 0.001 to 40% by mass, more preferably 0.01 to 20% by mass, and more preferably 0.1 to 10% by mass, relative to the total mass of the coating liquid.

The liquid medium is preferably an organic solvent. The organic solvent may be a fluorine-based organic solvent, a non-fluorine-based organic solvent, or a mixture of both.

Specific examples of the fluorine-based organic solvent include fluorinated alkanes, fluorinated aromatic compounds, fluoroalkyl ethers, fluorinated alkylamines, and fluoroalcohols.
Specific examples of fluorinated alkanes are preferably compounds having 4 to 8 carbon atoms. Commercially available products include C ₆ F ₁₃ H (manufactured by AGC, Asahiklin (registered trademark) AC-2000), C ₆ F ₁₃ C ₂ H ₅ (manufactured by AGC, Asahiklin (registered trademark) AC-6000), and C ₂ F ₅ CHFCHFCF ₃ (manufactured by Chemours, Vertrel (registered trademark) XF).
Specific examples of the fluorinated aromatic compound include hexafluorobenzene, trifluoromethylbenzene, perfluorotoluene, and bis(trifluoromethyl)benzene.
The fluoroalkyl ether is preferably a compound having 4 to 12 carbon atoms. Commercially available products _{include CF3CH2OCF2CF2H} (manufactured by AGC, _Asahiklin (registered trademark) AE-3000), _C4F9OCH3 (manufactured by 3M, _Novec (registered trademark) 7100), _{C4F9OC2H5 (} manufactured by _3M , _Novec (registered trademark) 7200), _{and C2F5CF} ( _OCH3 ) _C3F7 (manufactured by _3M , Novec (registered trademark) ₇₃₀₀ ) _.
Specific examples of fluorinated alkylamines include perfluorotripropylamine and perfluorotributylamine.
Specific examples of fluoroalcohols include 2,2,3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, and hexafluoroisopropanol.
The non-fluorinated organic solvent is preferably a compound consisting only of hydrogen atoms and carbon atoms, or a compound consisting only of hydrogen atoms, carbon atoms, and oxygen atoms, and examples thereof include hydrocarbon organic solvents, alcohol organic solvents, ketone organic solvents, ether organic solvents, and ester organic solvents.

The coating liquid preferably contains 60 to 99.999% by mass of the liquid medium, more preferably 85 to 99.99% by mass, and even more preferably 90 to 99.9% by mass.

The present coating liquid may contain, in addition to the present surface treatment agent and the liquid medium, other components as long as the effects of the present invention are not impaired.
Examples of other components include known additives such as acid catalysts and base catalysts that promote the hydrolysis and condensation reaction of hydrolyzable silyl groups.
The content of other components in the present coating liquid is preferably 10% by mass or less, and more preferably 1% by mass or less.

The total concentration of the surface treatment agent and other components (hereinafter also referred to as "solids concentration") is preferably 0.001 to 40% by mass, more preferably 0.01 to 20% by mass, even more preferably 0.01 to 10% by mass, and particularly preferably 0.01 to 1% by mass. The solids concentration of the coating liquid is a value calculated from the mass of the coating liquid before heating and the mass after heating for 4 hours in a convection dryer at 120°C.

[Goods]
The article of the present invention (hereinafter also referred to as "the article") has a substrate and a surface layer disposed on the substrate, and preferably has a primer layer between the substrate and the surface layer.
The surface layer is a layer formed from the present surface treatment agent or the present coating liquid, and contains a condensate of the above-mentioned fluorine-containing ether compound.

The material and shape of the substrate may be selected appropriately depending on the intended use of the article. Examples of substrate materials include glass, resin, sapphire, metal, ceramic, stone, and composites thereof. Glass may be chemically strengthened. Substrates that require water and oil repellency in particular include touch panel substrates, display substrates, and substrates that form the housings of electronic devices. Touch panel substrates and display substrates are translucent. "Translucent" means that the normal incidence visible light transmittance in accordance with JIS R3106:1998 (ISO 9050:1990) is 25% or greater. Glass or transparent resin is preferred as the material for touch panel substrates.

The substrate may be subjected to a surface treatment such as corona discharge treatment, plasma treatment, or plasma graft polymerization treatment on the surface on which the undercoat layer is to be formed. A surface that has been subjected to a surface treatment provides even better adhesion between the substrate and the undercoat layer, thereby further improving the abrasion resistance of the surface layer. Corona discharge treatment or plasma treatment is preferred as the surface treatment, as it provides even better abrasion resistance to the surface layer.

The underlayer is preferably a layer containing a silicon-containing oxide (preferably silicon oxide), and may further contain other elements. When the underlayer contains silicon oxide, the reactive silyl groups of the fluorine-containing ether compound undergo dehydration condensation, forming Si-O-Si bonds with the underlayer, resulting in a surface layer with excellent abrasion resistance.

The silicon oxide content in the underlayer is preferably 65% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and particularly preferably 90% by mass or more. When the silicon oxide content is at or above the lower limit, sufficient Si-O-Si bonds are formed in the underlayer, ensuring sufficient mechanical properties of the underlayer. The silicon oxide content is the remainder obtained by subtracting the total content of other elements (in the case of oxides, the amount converted into oxide) from the mass of the underlayer.

From the standpoint of durability of the surface layer, it is preferable that the oxide in the underlayer further contains one or more elements selected from alkali metal elements, alkaline earth metal elements, platinum group elements, boron, aluminum, phosphorus, titanium, zirconium, iron, nickel, chromium, molybdenum, and tungsten. The inclusion of these elements strengthens the bond between the underlayer and the fluorine-containing ether compound, improving abrasion resistance.

The thickness of the underlayer is preferably 1 to 200 nm, more preferably 2 to 20 nm. If the thickness of the underlayer is equal to or greater than the lower limit, the underlayer's adhesiveness-improving effect is likely to be fully achieved. If the thickness of the underlayer is equal to or less than the upper limit, the abrasion resistance of the underlayer itself is enhanced. Methods for measuring the thickness of the underlayer include cross-sectional observation of the underlayer using an electron microscope (SEM, TEM, etc.), or methods using an optical interference film thickness meter, spectroscopic ellipsometer, step gauge, etc.

The underlayer can be formed, for example, by depositing a deposition material having a desired composition for the underlayer on the surface of the substrate.
An example of the vapor deposition method is vacuum deposition, in which a deposition material is evaporated in a vacuum chamber and attached to the surface of a substrate.
The temperature during deposition (for example, the temperature of the boat in which the deposition material is placed when a vacuum deposition apparatus is used) is preferably 100 to 3000°C, more preferably 250 to 3000°C.
The pressure during deposition (for example, when using a vacuum deposition apparatus, the absolute pressure in a tank in which the deposition material is placed is preferably 1 Pa or less, more preferably 0.1 Pa or less.
When the underlayer is formed using a deposition material, one deposition material may be used, or two or more deposition materials containing different elements may be used.
Examples of methods for evaporating the deposition material include a resistance heating method in which the deposition material is melted and evaporated on a resistance heating boat made of a high-melting-point metal, and an electron gun method in which the deposition material is irradiated with an electron beam to directly heat the deposition material, melting and evaporating the surface. The electron gun method is preferred as a method for evaporating the deposition material because it can evaporate high-melting-point substances due to its ability to heat locally, and because areas not irradiated by the electron beam are at low temperatures, there is no risk of reaction with the container or contamination with impurities. The deposition material used in the electron gun method is preferably a molten granular or sintered material because it is less likely to scatter even when an air current is generated.

The surface layer contains a condensate of the above-mentioned fluorine-containing ether compound. The condensate of the fluorine-containing ether compound includes a structure in which silanol groups (Si-OH) are formed by hydrolysis of hydrolyzable silyl groups in the fluorine-containing ether compound, and the silanol groups undergo an intermolecular condensation reaction to form Si-O-Si bonds, and a structure in which silanol groups in the fluorine-containing ether compound undergo a condensation reaction with silanol groups or Si-OM groups (where M is an alkali metal element) on the surface of the substrate or underlayer to form Si-O-Si bonds. The surface layer may also contain a condensate of a fluorine-containing compound other than a fluorine-containing ether compound. That is, the surface layer contains a fluorine-containing compound having reactive silyl groups in a state in which some or all of the reactive silyl groups of the fluorine-containing compound have undergone condensation reaction.

The thickness of the surface layer is preferably 1 to 100 nm, more preferably 1 to 50 nm. When the thickness of the surface layer is equal to or greater than the lower limit, the effect of the surface layer can be sufficiently obtained. When the thickness of the surface layer is equal to or less than the upper limit, the utilization efficiency is high.
The thickness of the surface layer is the thickness obtained by an X-ray diffractometer for thin film analysis. The thickness of the surface layer can be calculated from the oscillation period of the interference pattern obtained by X-ray reflectivity analysis using the X-ray diffractometer for thin film analysis.

The article is preferably a touch panel. In this case, the surface layer is preferably formed on the surface of a member that constitutes the surface of the touch panel that is touched by a finger.

[Production method for articles]
The method for producing the present article is a method for forming a surface layer on a substrate by a dry coating method or a wet coating method using the present surface treatment agent or the present coating liquid.

The present surface treatment agent can be used as is in a dry coating method. The present surface treatment agent is suitable for forming a surface layer with excellent adhesion by a dry coating method. Examples of dry coating methods include vacuum deposition, CVD, and sputtering. The vacuum deposition method is preferably used from the viewpoints of suppressing decomposition of the fluorinated ether compound and simplicity of the equipment.
For vacuum deposition, a pellet-shaped material in which the present surface treatment agent is supported on a porous metal body made of a metal material such as iron or steel may be used. The pellet-shaped material supporting the present surface treatment agent can be produced by impregnating a porous metal body with a solution of the present surface treatment agent and then drying it to remove the liquid medium. The present coating liquid can be used as the solution of the present surface treatment agent.

This coating liquid can be suitably used in wet coating methods. Wet coating methods include spin coating, wipe coating, spray coating, squeegee coating, dip coating, die coating, inkjet coating, flow coating, roll coating, casting, Langmuir-Blodgett coating, and gravure coating.

In order to improve the abrasion resistance of the surface layer, an operation for promoting the reaction between the fluorine-containing ether compound and the substrate (or undercoat layer) may be carried out as necessary. Examples of such an operation include heating, humidification, and light irradiation. For example, the substrate on which the surface layer has been formed can be heated in a moist atmosphere to promote reactions such as the hydrolysis reaction of hydrolyzable groups, the reaction between hydroxyl groups on the surface of the substrate and silanol groups, and the formation of siloxane bonds through the condensation reaction of silanol groups.
After the surface treatment, compounds in the surface layer that are not chemically bonded to other compounds or the substrate may be removed as needed, for example, by pouring a solvent over the surface layer or wiping it off with a cloth soaked in the solvent.

The present invention will be described in detail below using examples. Examples 2, 3, 5, 6, 8, 9, 11, 12, 14, 15, 17, and 18 are working examples, and Examples 1, 4, 7, 10, 13, and 16 are comparative examples. However, the present invention is not limited to these examples.

[Synthesis of Fluorine-Containing Ether Compound X1-1]
<Synthesis of Compound a-2>
A 500 mL three-neck flask was charged with 2.9 g of 20% aqueous KOH solution, 33 g of tert-butyl alcohol, 110 g of 1,3-bis(trifluoromethyl)benzene, 220 g of compound a-1, and 14.6 g of perfluoropropyl vinyl ether. The mixture was then stirred at 40°C for 20 hours under a nitrogen atmosphere. After stirring, the mixture was washed once with a dilute aqueous hydrochloric acid solution, and the organic layer was concentrated using an evaporator to obtain 233 g of a crude product. The obtained crude product was separated and purified by silica gel column chromatography to obtain 100 g of compound a-2.

HO-CH ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }-OCF ₂ CH ₂ -OH ... (a-1)
m ≒ 14, n ≒ 13

CF ₃ CF ₂ CF ₂ OCHFCF ₂ OCH ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }-OCF ₂ CH ₂ -OH...(a-2)
m ≒ 14, n ≒ 13

<Synthesis of Compound a-3>
In a 100 mL recovery flask, 30.0 g of compound a-2, 0.9 g of sodium fluoride powder, and 30 g of dichloropentafluoropropane (manufactured by AGC, Asahiklin (registered trademark) AK-225) were placed, and 3.5 g of CF ₃ CF ₂ CF ₂ OCF(CF ₃ )COF was added. Next, the mixture was stirred at 50°C for 24 hours under a nitrogen atmosphere. The sodium fluoride powder was removed using a pressure filter, and then the mixture was distilled off under reduced pressure. The obtained crude product was diluted with AC-2000 (manufactured by AGC, Asahiklin (registered trademark) AC-2000) and passed through a silica gel column. The recovered solution was concentrated using an evaporator to obtain 31.8 g of compound a-3.

CF ₃ CF ₂ CF ₂ OCHFCF ₂ OCH ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }OCF ₂ CH ₂ OC(=O)CF(CF ₃ )OCF ₂ CF ₂ CF ₃ ...(a-3)
m ≒ 14, n ≒ 13

<Synthesis of Compound a-4>
An autoclave (made of nickel, internal volume 1 L) was prepared, and a condenser maintained at 20° C., a NaF pellet packed bed, and another condenser maintained at 0° C. were installed in series at the gas outlet of the autoclave. In addition, a liquid return line was installed to return the coagulated liquid from the condenser maintained at 0° C. to the autoclave.
750 g of ClCF ₂ CFClCF ₂ OCF ₂ CF ₂ Cl (hereinafter also referred to as "CFE-419") was charged into an autoclave and stirred while maintaining the temperature at 25° C. Nitrogen gas was blown into the autoclave at 25° C. for 1 hour, and then 20% fluorine gas was blown into it at a flow rate of 2.0 L/hour at 25° C. for 1 hour. Next, while blowing in 20% fluorine gas at the same flow rate, a solution prepared by dissolving 31.0 g of compound a-3 in 124 g of CFE-419 was injected into the autoclave over 4.3 hours.
Next, while blowing in 20% fluorine gas at the same flow rate, the internal pressure of the autoclave was increased to 0.15 MPa (gauge pressure). 4 mL of a benzene solution containing 0.05 g/mL of benzene in CFE-419 was injected into the autoclave while heating from 25°C to 40°C, and the benzene solution inlet of the autoclave was closed. After stirring for 15 minutes, 4 mL of the benzene solution was again injected while maintaining the temperature at 40°C, and the inlet was closed. The same operation was repeated three more times. The total amount of benzene injected was 0.17 g.
Stirring was continued for another hour while blowing in 20% fluorine gas at the same flow rate. Then, the pressure inside the autoclave was adjusted to atmospheric pressure, and nitrogen gas was blown in for one hour. The contents of the autoclave were concentrated using an evaporator, yielding 31.1 g of compound a-4.

CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ O {(CF ₂ O) _m (CF ₂ CF ₂ O) _n } CF ₂ CF ₂ OC (=O) CF (CF ₃ ) OCF ₂ CF ₂ CF ₃ ... (a-4)
m ≒ 14, n ≒ 13

<Synthesis of Compound a-5>
30.0 g of compound a-4 and 60 g of AK-225 were placed in a PFA round-bottom flask. The mixture was stirred while cooled in an ice bath, and 2.0 g of methanol was slowly added dropwise from the dropping funnel under a nitrogen atmosphere. The mixture was stirred for 12 hours while bubbling with nitrogen. The reaction mixture was concentrated using an evaporator to obtain 27.6 g of compound a-5.

CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }OCF ₂ C(=O)OCH ₃ ...(a-5)
m ≒ 14, n ≒ 13

<Synthesis of Compound a-6>
In a 100 mL three-necked recovery flask, 0.18 g of lithium chloride was dissolved in 18.3 g of ethanol. 25.0 g of compound a-5 was added to this, and while cooling in an ice bath, a solution of 0.75 g of sodium borohydride dissolved in 22.5 g of ethanol was slowly added dropwise. The ice bath was then removed, and stirring was continued while slowly raising the temperature to room temperature (23 ° C). After stirring at room temperature (23 ° C) for 12 hours, aqueous hydrochloric acid was added dropwise until the solution became acidic. 20 mL of AC-2000 was added to the solution into which aqueous hydrochloric acid had been added dropwise, and the mixture was washed once with water and once with saturated saline, and the organic phase was recovered. The recovered organic phase was concentrated using an evaporator and subjected to column purification, yielding 24.6 g of compound a-6.

CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }OCF ₂ CH ₂ OH ... (a-6)
m ≒ 14, n ≒ 13

<Synthesis of Compound a-7>
Into a 100 mL two-necked recovery flask, 20.0 g of compound a-6, 0.21 g of tetrabutylammonium hydrogen sulfate, 1.76 g of allyl bromide, and 2.6 g of 30% aqueous sodium hydroxide solution were added and stirred at 60°C for 8 hours. After completion of the reaction, 20 g of AC-2000 was added, and the mixture was washed once with a dilute aqueous hydrochloric acid solution, and the organic phase was recovered. The recovered organic phase was passed through a silica gel column, and the recovered solution was concentrated using an evaporator to obtain 19.8 g of compound a-7.

CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }OCF ₂ CH ₂ -OCH ₂ CH=CH _2... (a-7)
m ≒ 14, n ≒ 13

<Synthesis of Compound a-8>
A 30 mL four-neck flask equipped with a reflux condenser, a thermometer, and a stirrer was charged with 6 g of compound a-7, 6 g of 1,3-bis(trifluoromethyl)benzene, 0.018 g of triacetoxymethylsilane, and 0.41 g of trichlorosilane, and the mixture was stirred at 5°C for 30 minutes under a nitrogen stream. Subsequently, a xylene solution (0.028 ml) containing 2% of a Pt complex of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane was added, and the mixture was heated to 60°C and stirred at this temperature for 5 hours. Thereafter, the volatiles were distilled off, and the mixture was subjected to column purification, yielding 5.7 g of compound a-8.

CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }OCF ₂ CH ₂ -OCH ₂ CH ₂ CH ₂ SiCl ₃ ...(a-8)
m ≒ 14, n ≒ 13

<Synthesis of Compound a-9>
5 g of compound a-8 and 5 g of 1,3-bis(trifluoromethyl)benzene were charged into a 30 ml four-neck flask equipped with a reflux condenser, a thermometer, and a stirrer, and the mixture was stirred at 5°C for 30 minutes under a nitrogen stream. Subsequently, a diethyl ether solution (6.91 ml) containing 0.9 mol/L of allyl magnesium bromide was added, and the mixture was heated to room temperature (23°C) and stirred at this temperature for 10 hours. Thereafter, the mixture was cooled to 5°C, and methanol (2 ml) was added. The mixture was then heated to room temperature (23°C), and insoluble matter was filtered. Subsequently, the volatile matter was distilled off, and the nonvolatile matter was diluted with perfluorohexane and washed with methanol in a separatory funnel. Subsequently, the volatile matter was distilled off to obtain 5 g of compound a-9.

CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }OCF ₂ CH ₂ -OCH ₂ CH ₂ CH ₂ Si (CH ₂ CH=CH ₂ ) ₃ ...(a-9)
m ≒ 14, n ≒ 13

<Synthesis of Compound X1-1>
5.0 g of compound a-9, 0.03 g of a xylene solution of platinum/1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum content: 2% by mass), 0.36 g of trimethoxysilane, 0.01 g of aniline, and 2.0 g of 1,3-bis(trifluoromethyl)benzene were added and stirred at room temperature (23° C.) for 8 hours. The solvent and other components were distilled off under reduced pressure, and the resulting mixture was filtered through a membrane filter with a pore size of 0.5 μm to obtain 5.2 g of compound X1-1.

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 (OCF2CF2 ) m12 } -OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si} ( _{OCH3 ) 3 ) 3} ...(X1-1)
Average number of m11: 13.9, average number of m12: 15.4

The average numbers of (OCF ₂ ) and (OCF ₂ CF ₂ ) in compound X1-1 were determined by ¹⁹ F-NMR. The average numbers of (OCF ₂ ) and (OCF ₂ CF ₂ ) in each of the fluorinated ether compounds described below were also determined in the same manner as for compound X1-1.

[Synthesis of Fluorine-Containing Ether Compound X1-2]
<Synthesis of Compound b-1>
5 g of ethylene glycol, 7.5 g of 48% KOH aqueous solution, 6 g of water, and tert-butyl alcohol were mixed in a 100 ml four-neck flask, and 5 g of perfluoropropyl vinyl ether was added dropwise from a dropping funnel. Next, the mixture was stirred at 40°C for 20 hours under a nitrogen atmosphere. After stirring, the mixture was washed once with a dilute hydrochloric acid aqueous solution, and the organic layer was concentrated using an evaporator, followed by column purification to obtain 22 g of compound b-1.

CF ₃ CF ₂ CF ₂ OCHFCF ₂ OCH ₂ CH ₂ OH (b-1)

<Synthesis of Compound b-2>
A 100 ml four-neck flask was charged with 20 g of compound b-1, 10 g of triethylamine, and 200 g of AC-2000, to which 15 g of tosyl chloride was added. The mixture was mixed at 40°C for 8 hours, filtered, concentrated, and purified by column chromatography to obtain 18 g of compound b-2.

CF ₃ CF ₂ CF ₂ OCHFCF ₂ OCH ₂ CH ₂ O-Ts...(b-2)

<Synthesis of Compound b-4>
A 100 ml four-neck flask was charged with 23 g of the following compound b-3, 23 g of 1,3-bis(trifluoromethyl)benzene, 2 g of cesium carbonate, and 3 g of b-2. The mixture was stirred at 70°C for 20 hours under a nitrogen atmosphere. The mixture was washed with a dilute aqueous hydrochloric acid solution, washed three times with water, concentrated, and purified with a column to obtain 24 g of compound b-4.

HO-CH ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }-OCF ₂ CH ₂ -OH...b-3
m ≒ 14, n ≒ 12

CF ₃ CF ₂ CF ₂ OCHFCF ₂ OCH ₂ CH ₂ O-CH ₂ CF ₂ {(OCF ₂ ) _m (OCF ₂ CF ₂ ) _n }-OCF ₂ CH ₂ -OH...(b-4)
m ≒ 14, n ≒ 12

<Synthesis of Fluorine-Containing Ether Compound X1-2>
Fluorine-containing ether compound X1-2 was synthesized in the same manner as in the synthesis of fluorine-containing ether compound X1-1, except that compound b-4 was used instead of compound a-2.
The fluorine-containing ether compound X1-2 differs from the fluorine-containing ether compound X1-1 in the arrangement of (OCF ₂ ) and (OCF ₂ CF ₂ ).

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X1-2)
Average number of m11: 13.9, average number of m12: 15.4

[Synthesis of Fluorine-Containing Ether Compound X2-1]
With reference to the synthesis of fluorine-containing ether compound X1-1, fluorine-containing ether compound X2-1 was obtained.

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X2-1)
Average number of m11: 22.3, average number of m12: 10.6

[Synthesis of Fluorine-Containing Ether Compound X2-2]
A fluorine-containing ether compound X2-2 was obtained in the same manner as in the synthesis of the fluorine-containing ether compound X1-2, except that a compound obtained by using diethylene glycol instead of ethylene glycol in the synthesis of the compound b-1 was used.
The fluorine-containing ether compound X2-2 differs from the fluorine-containing ether compound X2-1 in the arrangement of (OCF ₂ ) and (OCF ₂ CF ₂ ).

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X2-2)
Average number of m11: 22.3, average number of m12: 10.6

[Synthesis of Fluorine-Containing Ether Compound X3-1]
With reference to the synthesis of fluorine-containing ether compound X1-1, fluorine-containing ether compound X3-1 was obtained.

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X3-1)
Average number of m11: 25.9, average number of m12: 8.6

[Synthesis of Fluorine-Containing Ether Compound X3-2]
A fluorine-containing ether compound X3-2 was obtained in the same manner as in the synthesis of fluorine-containing ether compound X1-2, except that a compound obtained by using diethylene glycol instead of ethylene glycol in the synthesis of compound b-1 was used.
The fluorine-containing ether compound X3-2 differs from the fluorine-containing ether compound X3-1 in the arrangement of (OCF ₂ ) and (OCF ₂ CF ₂ ).

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X3-2)
Average number of m11: 25.9, average number of m12: 8.6

[Synthesis of Fluorine-Containing Ether Compound X4-1]
With reference to the synthesis of fluorine-containing ether compound X1-1, fluorine-containing ether compound X4-1 was obtained.

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X4-1)
Average number of m11: 28.5, average number of m12: 7.1

[Synthesis of Fluorine-Containing Ether Compound X4-2]
A fluorine-containing ether compound X4-2 was obtained in the same manner as in the synthesis of the fluorine-containing ether compound X1-2, except that a compound obtained by using diethylene glycol instead of ethylene glycol in the synthesis of the compound b-1 was used.
The fluorine-containing ether compound X4-2 differs from the fluorine-containing ether compound X4-1 in the arrangement of (OCF ₂ ) and (OCF ₂ CF ₂ ).

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X4-2)
Average number of m11: 28.5, average number of m12: 7.1

[Synthesis of Fluorine-Containing Ether Compound X5-1]
With reference to the synthesis of fluorine-containing ether compound X1-1, fluorine-containing ether compound X5-1 was obtained.

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X5-1)
Average number of m11: 31.6, average number of m12: 5.4

[Synthesis of Fluorine-Containing Ether Compound X5-2]
With reference to the synthesis of fluorine-containing ether compound X1-2, fluorine-containing ether compound X5-2 was obtained.
The fluorine-containing ether compound X5-2 differs from the fluorine-containing ether compound X5-1 in the arrangement of (OCF ₂ ) and (OCF ₂ CF ₂ ).

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X5-2)
Average number of m11: 31.6, average number of m12: 5.4

[Synthesis of Fluorine-Containing Ether Compound X6-1]
With reference to the synthesis of fluorine-containing ether compound X1-1, fluorine-containing ether compound X6-1 was obtained.

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X6-1)
Average number of m11: 33.6, average number of m12: 4.2

[Synthesis of Fluorine-Containing Ether Compound X6-2]
With reference to the synthesis of fluorine-containing ether compound X1-2, fluorine-containing ether compound X6-2 was obtained.
The fluorine-containing ether compound X6-2 differs from the fluorine-containing ether compound X6-1 in the arrangement of (OCF ₂ ) and (OCF ₂ CF ₂ ).

_CF3CF2CF2 - _{ ( _{OCF2 ) m11 ( OCF2CF2 ) m12} } _{-OCF2CH2 - OCH2CH2CH2CH2Si ( CH2CH2CH2Si ( OCH3} ) _{3 ) 3} (X6-2)
Average number of m11: 33.6, average number of m12: 4.2

[Preparation of the mixture]
Mixtures 1-1, 1-2, 2-1, 2-2, 3-1, 3-2, 4-1, 4-2, 5-1, 5-2, 6-1, and 6-2 were obtained by mixing the fluorinated ether compounds shown in Table 1. In preparing each mixture, the fluorinated ether compounds were mixed in such a ratio that the value of Y in formula (A-1) was the value shown in Table 1.

[Values of X and Y in Formula (A-1)]
Using the obtained fluorine-containing ether compound or mixture, the values of X and Y in formula (A-1) were calculated based on a chart obtained by 400 MHz ^19F -NMR measurement. Furthermore, based on the values of X and Y, the sufficiency of formula (A-1) and formula (A-2) was judged, and cases where the formula was satisfied were marked with "○" and cases where it was not satisfied were marked with "×". The results are shown in Table 1.
The ¹⁹ F-NMR measurement was carried out under the following measurement conditions.
Measuring device: “JNM-ECZ 400” manufactured by JEOL
Internal standard: 1,4-bistrifluoromethylbenzene

A typical chart obtained by ¹⁹ F-NMR measurement is shown in FIG.
FIG. 2 is a chart obtained by 400 MHz ¹⁹ F-NMR measurement using the mixture 5-1.
As shown in Figure 2, peaks were observed at chemical shifts of -50.5 to -51.2 ppm, -52.0 to -52.8 ppm, -53.8 to -54.5 ppm, -87.0 to -88.5 ppm, and -88.8 to -90.2 ppm. The peak at chemical shift -63.5 ppm in Figure 2 corresponds to 1,4-bistrifluoromethylbenzene.
Although not shown in the chart, peaks were observed in the above chemical shift range for other fluorine-containing ether compounds and mixtures.

[Examples 1 to 18]
A substrate (alkali-free glass (Eagle XG: product name, manufactured by Corning Incorporated, 50 mm x 50 mm, thickness 0.5 mm)) was placed in a vacuum deposition apparatus, and the inside of the vacuum deposition apparatus was evacuated to a pressure of 5 x 10 ^-3 Pa or less. A deposition vessel containing each fluorine-containing ether compound or mixture of each example listed in Table 1 was heated to 300°C by resistance heating, positioned 1000 mm away from one main surface of the substrate, and the fluorine-containing ether compound or mixture was vacuum-deposited. Film formation was terminated when the thickness of the fluorine-containing ether compound or mixture on the substrate reached 10 nm. Thereafter, the substrate on which the fluorine-containing ether compound or mixture had been deposited was heated at a temperature of 200°C for 30 minutes (post-treatment) to obtain a substrate (article) with a surface layer.

[Evaluation test]
The substrates with surface layers of Examples 1 to 18 were subjected to the following evaluation tests.

<Abrasion resistance (steel wool)>
For the surface layer, a reciprocating traverse tester (manufactured by KNT Corporation) was used in accordance with JIS L0849:2013 (ISO 105-X12:2001) to measure the number of reciprocating strokes at which the water contact angle became less than 100 degrees by reciprocating steel wool Bonstar (#0000) at a pressure of 98.07 kPa and a speed of 320 cm/min. The greater the number of reciprocating strokes, the smaller the deterioration in performance due to friction, and the more excellent the abrasion resistance. The evaluation criteria are as follows:
A (Excellent): 7001 or more reciprocating cycles B (Good): 6001 to 7000 reciprocating cycles C (Acceptable): 4001 to 6000 reciprocating cycles D (Unacceptable): 4000 or less reciprocating cycles (Water contact angle measurement method)
The contact angle of approximately 2 μL of distilled water placed on the surface of the surface layer was measured using a contact angle measuring device (DM-500, manufactured by Kyowa Interface Science Co., Ltd.). Measurements were taken at five different points on the surface of the surface layer, and the average value was calculated to determine the water contact angle. The 2θ method was used to calculate the contact angle.

<Lubricity>
The dynamic friction coefficient of the surface layer against artificial skin (PBZ13001, manufactured by Idemitsu Technofine Co., Ltd.) was measured using a load-varying friction and wear testing system (HHS2000, manufactured by Shinto Scientific Co., Ltd.) under conditions of a contact area of 3 cm x 3 cm and a load of 0.98 N. The smaller the dynamic friction coefficient, the better the lubricity. The evaluation criteria are as follows:
A (Excellent): Coefficient of dynamic friction is less than 0.02 B (Good): Coefficient of dynamic friction is 0.02 or more and less than 0.03 C (Acceptable): Coefficient of dynamic friction is 0.03 or more and less than 0.04 D (Unacceptable): Coefficient of dynamic friction is 0.04 or more

As shown in Table 1, it was confirmed that a surface layer excellent in lubricity and abrasion resistance could be formed by using a fluorine-containing ether compound satisfying formula (A-1) (Examples 2, 3, 5, 6, 8, 9, 11, 12, 14, 15, 17, and 18).
Furthermore, as shown in Table 1, it was confirmed that by using a fluorine-containing ether compound satisfying formula (A-2), a surface layer having superior at least one of lubricity and abrasion resistance could be formed (Examples 3, 6, 9, 12, 15, and 18).

Claims (7)

A surface treatment agent comprising a mixture of fluorine-containing ether compounds having a fluoropolyether chain containing a unit represented by (OCF ₂ ) and a unit represented by (OCF ₂ CF ₂ ), and a reactive silyl group,
The fluorine-containing ether compound has a structure represented by the following formula (1-1):
The surface treatment agent is characterized in that the following formula (A-1) is satisfied in a chart obtained by ¹⁹ F-NMR measurement of the mixture of fluorinated ether compounds:
Y>-0.0062X ² +0.1343X+0.1123...(A-1)
where X and Y are values determined based on a chart obtained by ^F -NMR measurement of the fluorinated ether compound using 1,4-bistrifluoromethylbenzene as an internal standard,
Chemical shift: a1, the integral value of the peak observed at −50.5 to −51.2 ppm
The integral value of the peak observed at chemical shifts of −52.0 to −52.8 ppm is a2,
The integral value of the peak observed at chemical shifts of −53.8 to −54.5 ppm is a3,
The integral value of the peak observed at chemical shifts of −87.0 to −88.5 ppm is designated as b1,
When the integral value of the peak observed at chemical shifts of −88.8 to −90.2 ppm is defined as b2,
X means {(a1+a2+a3)/2}/{(b1+b2)/4},
Y means (a3)/(a1+a2+a3).
[R ^f1 -(OCF ₂ ) _m11 ・(OCF ₂ CF ₂ ) _m12 -O-R ¹ ] _j -L ¹ -(R ¹¹ -T ¹¹ ) _x1 ...(1-1)
however,
R ^f1 is a fluoroalkyl group having 1 to 20 carbon atoms, and when there are a plurality of R ^f1s , the plurality of R ^f1s may be the same or different from each other,
m11 is a positive number equal to or greater than 2,
m12 is a positive number equal to or greater than 2,
R ¹ is an alkylene group or a fluoroalkylene group, and when there are a plurality of R ^1s , the plurality of R ^1s may be the same or different (however, when R ¹ is a fluoroalkylene group, R ¹ is a fluoroalkylene group other than —CF ₂ — and —CF ₂ CF ₂ —).
j is an integer of 1 or greater,
L1 ^is a single bond or a j+x monovalent organic group which may have N, O, S, or Si and which may have a branch point, and atoms bonding to ^R1 and ^R11 are each independently N, O, S, Si, a carbon atom constituting a branch point, or a carbon atom having an oxo group (=O);
R ¹¹ is an alkylene group in which the atom bonded to L ¹ may be an ethereal oxygen atom or which may have an ethereal oxygen atom between carbon atoms,
T ¹¹ is -SiR ^a11 _z11 R ^a12 _3-z11 , R ^a11 is a hydroxyl group or a hydrolyzable group, and when there are multiple R ^a11 , the multiple R ^a11s may be the same or different, R ^a12 is a non-hydrolyzable group, and when there are multiple R ^a12s , the multiple R ^a12s may be the same or different, and z11 is an integer of 1 to 3,
x1 is an integer of 1 or more. The surface treatment agent according to claim 1, wherein X in formula (A-1) is 2 to 8. 3. The surface treatment agent according to claim 1, wherein the fluorine-containing ether compound satisfies the following formula (A-2) in a chart obtained by ¹⁹ F-NMR measurement:
Y>-0.0056X ² +0.1231X+0.2119...(A-2)
However, X and Y in formula (A-2) are the same as X and Y in formula (A-1). A coating liquid comprising the surface treatment agent according to any one of claims 1 to 3 and a liquid medium. An article having a surface layer formed on a substrate using the surface treatment agent described in any one of claims 1 to 3 or the coating liquid described in claim 4. The article described in claim 5, wherein the article is a touch panel and the surface layer is provided on the surface of a member that constitutes the surface of the touch panel that is touched by a finger. A method for manufacturing an article, comprising forming a surface layer on a substrate by a dry coating method or a wet coating method using the surface treatment agent described in any one of claims 1 to 3 or the coating liquid described in claim 4.