JP7365086B1 - Perfluoropolyether group-containing phosphonate compound, surface treatment agent, and article treated with the surface treatment agent - Google Patents

Abstract

[Problem] When used as a surface treatment agent, it forms a cured film with excellent water and oil repellency, abrasion resistance, stain resistance, lubricity, ease of fingerprint stain removal, mold releasability, and heat resistance on the surface of a substrate. A possible perfluoropolyether group-containing phosphonate compound is provided. According to the present invention, there is provided a perfluoropolyether group-containing phosphonate compound represented by the following formula (1), which comprises the formula (1) A-O-Rf-(CF2)x-L-(CH2 )y-P(=O)(OR1)2-z(OH)z In formula (1), A is a perfluoroalkyl group having 1 to 4 carbon atoms, and Rf is a perfluoropolyether group. , L is a linking group. [Selection diagram] None

Description

The present invention relates to a perfluoropolyether group-containing phosphonate compound, a surface treatment agent, and an article treated with the surface treatment agent.

Certain fluorine-containing compounds have very low surface free energy, so when used for surface treatment of substrates, they can provide excellent water and oil repellency, stain resistance, mold releasability, lubricity, etc. It is known. When used for surface treatment purposes, excellent water and oil repellency, abrasion resistance, stain resistance, lubricity, ease of removing fingerprint stains, and durability are required. Surface treatment technology using phosphonate compounds is known as a technology for improving the surface of metal substrates, and is used for antifouling treatment of decorative parts such as stainless steel, automobile parts, home appliances, interior building materials, etc., and as a mold release agent. Examples of uses include:

As a surface treatment agent to meet the above requirements, for example, a fluorine-containing polyetherphosphonic acid ester compound represented by the following formula (I) has been proposed (Patent Document 1).
( _R2O )( _R1O )P(O)( _CH2 ) _a CF( _CF3 ) [ _OCF2CF ( _CF3 )] _b O( _CF2 ) _c
O[CF( _CF3 ) _CF2O ] _d CF( _CF3 )( _CH2 ) _e P(O)( _OR3 )( _OR4 )...(I)
(Here, R ₁ , R ₂ , R ₃ , R ₄ are hydrogen atoms, alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, aralkyl groups, or some or all of the hydrogen atoms of these groups are halogen atoms. a, b, c, d, e are integers satisfying 2≦a+e≦8, b+d≦28, 1≦c≦10, and b and d can be 0). The represented fluorine-containing polyether phosphonic acid ester compound.

The following proposal has been made as a surface treatment agent with improved water and oil repellency, ease of removing fingerprint stains, and abrasion resistance (Patent Document 2). The surface treatment agent is a surface treatment agent for substrates containing a perfluoropolyether group-containing phosphate compound, and the perfluoropolyether group-containing phosphate compound is a compound represented by the following formula (II).
B ¹ -(C _m F _2m O) _n1 -A ¹ ...(II)
During the ceremony,
A ¹ is a monovalent organic group having one or more phosphate groups at the end,
B ¹ is R ^F1 -O-, D ¹ -Q ¹ -O-CH ₂ - or A ² -O-,
Here, R ^F1 is a perfluoroalkyl group having 1 to 6 carbon atoms,
D ¹ is CF ₃ - or CF ₃ -O-,
Q ¹ is a fluoroalkylene group having 1 to 20 carbon atoms containing one or more hydrogen atoms, or a fluoroalkylene group having 2 to 20 carbon atoms containing one or more hydrogen atoms and having an etheric oxygen atom between carbon atoms. , an alkylene group having 1 to 20 carbon atoms, or an alkylene group having 2 to 20 carbon atoms having an etheric oxygen atom between carbon atoms,
^A2 is a monovalent organic group having one or more phosphate groups at the end,
m is an integer from 1 to 6,
n1 is an integer from 2 to 200,
(C _m F _2m O) _n1 is a group represented by the following formula (2-1-a).
(CF ₂ CF ₂ O) _n4 (CF ₂ CF ₂ CF ₂ CF ₂ O) _n5 ... (2-1-a)
During the ceremony,
n4 is an integer of 1 or more,
n5 is an integer of 1 or more,
However, n4+n5 is an integer from 2 to 200,
(CF ₂ CF ₂ O) and (CF ₂ CF ₂ CF ₂ CF ₂ O) are arranged alternately.

Furthermore, a metal surface treatment agent using a compound of the following formula (III) has been disclosed (Patent Document 3).
[R _f -O-CFY-L-O] _m P(=O) (O ^- Z ⁺ ) _3-m (III)
[In the formula, L is (a) -CH ₂ -(OCH ₂ CH ₂ ) n- (n is an integer of 0 to 3) and (b) -CO-NR'-(CH ₂ ) _q - (R' is H or C _1-4 alkyl, q is an integer from 1 to 4), m is 1, Y is -F or -CF ₃ , Z+ is H+, M+ (M is an alkali metal), N(R) ₄ + (R is the same or different and H or C _1-6 alkyl), R _f is a polyperfluoroalkylene oxide chain]

In addition, the following proposals have been made as surface treatment agents with improved water and oil repellency, fingerprint stain removability, and abrasion resistance. (Patent Document 4)
A-Rf ¹ -Q ¹ -Q ² -(CH ₂ ) _a -P(=O)(OX) ₂ (IV)
(In formula (IV), A is a -CF ₃ group, -CF ₂ CF ₃ group, or a group represented by the following formula (IV-2), and Rf ¹ is -(CF ₂ ) _d -(OCF ₂ ) _p (OCF ₂ CF ₂ ) _q (OCF ₂ CF ₂ CF ₂ ) _r (OCF ₂ CF ₂ CF ₂ CF ₂ ) _s (OCF(CF ₃ )CF ₂ ) _t −O(CF ₂ ) _d −, where d is Each independently is an integer from 0 to 5, p, q, r, s, and t are each independently an integer from 0 to 200, and p+q+r+s+t is 3 to 200, and each unit shown in parentheses is May be combined randomly.
Q ¹ is a divalent linking group,
^Q2 is a divalent linking group having silicon atoms at both ends,
X is each independently a hydrogen atom, an alkali metal atom, an unsubstituted or substituted alkyl group having 1 to 5 carbon atoms, an aryl group, or J ₃ Si- (J is independently an unsubstituted or substituted alkyl group having 1 to 5 carbon atoms) or aryl group), and a is an integer of 2 to 20. )
-Q ¹ -Q ² -(CH ₂ ) _a -P(=O)(OX) ₂ (IV-2)

Patent No. 4245050 Patent No. 6769304 Patent No. 3574222 Patent No. 6488890

However, there were cases where the water repellency, oil repellency, or heat resistance was insufficient. For example, the compound represented by the above formula (I) of Patent Document 1 was found to have insufficient water and oil repellency. Further, it was found that the compound represented by the above formula (II) of Patent Document 2 or the formula (III) of Patent Document 3 has poor heat resistance. Further, it was found that the compound represented by formula (IV) of Patent Document 4 has a complicated synthesis process.

More specifically, the compound represented by formula (I) has a bulky _CF3 group in the side chain of the fluorine chain moiety, has a large coefficient of dynamic friction, and has antifouling properties and easy removal of fingerprint stains. It turned out to be inferior. In addition, it was found that because the molecule has phosphonate functional groups at both ends, molecular mobility is reduced and water and oil repellency and abrasion resistance are insufficient.
Further, in the compounds represented by formulas (II) and (III), the fluorine chain and the phosphonate functional group are connected through a phosphate ester bond (C--O--P). It was found that this bond has a small bond energy, is easily hydrolyzed, and has poor thermal and chemical stability.
Further, the compound represented by formula (IV) contains a silicon atom between the fluorine chain and the phosphonate functional group, and the synthesis process is complicated, which is a problem in production.

The present invention was made in view of the above circumstances, and when used as a surface treatment agent, it provides water and oil repellency, abrasion resistance, stain resistance, lubricity, ease of fingerprint stain removal, and release properties to the surface of a base material. Provided is a perfluoropolyether group-containing phosphonate compound that can form a cured film with excellent moldability and heat resistance. In addition, we also provide surface treatment agents and surface treatments that can form cured films with excellent water and oil repellency, abrasion resistance, stain resistance, lubricity, ease of fingerprint stain removal, mold releasability, and heat resistance on the surface of substrates. An article comprising a cured film of an agent is provided.

As a result of intensive studies to solve the above problems, the present inventors found that when a perfluoropolyether group-containing phosphonate compound having a specific structure is used as a surface treatment agent, the surface of the base material has water and oil repellency and wear resistance. The present inventors have discovered that it is possible to form a film with excellent properties such as hardness, antifouling properties, lubricity, ease of removing fingerprint stains, mold releasability, and heat resistance, and have completed the present invention.

The following invention is provided.
[1] A perfluoropolyether group-containing phosphonate compound represented by the following general formula (1),
A-O-Rf-(CF ₂ ) _x -L-(CH ₂ ) _y -P(=O) (OR ¹ ) _2-z (OH) _z (1)
In the general formula (1),
A is a perfluoroalkyl group having 1 to 4 carbon atoms,
Rf has a structure represented by the following general formula (2), and each bonding unit in parentheses may be randomly bonded,
( _CF2O ) _p ( _{CF2CF2O ) q} ( _{CF2CF2CF2O ) r} ( _{CF2CF2CF2CF2O} ) _{s (} CF( _{CF3 ) CF2O ) t} ( ₂ )
In the general formula (2),
p, q, r, s, t are each independently an integer of 0 to 100, p + q + r + s + t is an integer of 10 to 100,
L is a single bond, C(=O)NR ² , CH ₂ O or CH ₂ , R ² is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, or an aryl group,
x is an integer from 1 to 2,
y is an integer from 1 to 4,
z is an integer from 0 to 2,
R ¹ is a hydrocarbon group having 1 to 4 carbon atoms or SiR ³ ₃ ,
R ³ is a hydrocarbon group having 1 to 4 carbon atoms,
Compound.
[2] The compound according to [1], wherein in the general formula (2), p is an integer of 1 or more, and q is an integer of 1 or more.
[3] In the general formula (1),
A is ₃ CF groups,
Rf has a structure represented by the following general formula (2-1), and each bonding unit in parentheses may be randomly bonded,
(CF ₂ O) _p (CF ₂ CF ₂ O) _q (2-1)
L is _CH2O or _CH2 ,
In the general formula (2-1), p and q are each independently an integer of 1 to 30,
The compound according to [1] or [2], wherein p+q is an integer of 10 to 50.
[4] The compound according to any one of [1] to [3], which has a number average molecular weight of more than 1,500.
[5] A surface treatment agent containing the compound according to any one of [1] to [4] and a volatile solvent.
[6] An article comprising a base material and a cured film of the surface treatment agent of [5] on the surface of the base material.
[7] The article according to [6], wherein the base material is metal.
[8] The article according to [6], wherein the base material is a metal oxide.

Embodiments of the present invention will be described below. Various features shown in the embodiments described below can be combined with each other. Further, the invention is established independently for each characteristic matter.

1. Perfluoropolyether group-containing phosphonate compound The compound according to one embodiment of the present invention (hereinafter also referred to as "compound P") is a perfluoropolyether group-containing phosphonate compound represented by the following general formula (1). Each element in general formula (1) will be explained below.
A-O-Rf-(CF ₂ ) _x -L-(CH ₂ ) _y -P(=O) (OR ¹ ) _2-z (OH) _z (1)

A is a perfluoroalkyl group having 1 to 4 carbon atoms. The perfluoroalkyl group preferably has a linear structure from the viewpoint of water repellency. Examples of linear perfluoroalkyl groups include CF ₃ group (CF ₃ -), CF ₃ CF ₂ group (CF ₃ CF ₂ -), CF ₃ CF ₂ CF ₂ group (CF ₃ CF ₂ CF ₂ -) , or a CF ₃ CF ₂ CF ₂ CF ₂ group (CF ₃ CF ₂ CF ₂ CF ₂ -). The perfluoroalkyl group is preferably a CF ₃ group (CF ₃ -).

Rf has a structure represented by the following general formula (2).
( _CF2O ) _p ( _{CF2CF2O ) q} ( _{CF2CF2CF2O ) r} ( _{CF2CF2CF2CF2O} ) _{s (} CF( _{CF3 ) CF2O ) t} ( ₂ )

In the structure of formula (2), each bond unit in parentheses, ie, "CF ₂ O", "CF ₂ CF ₂ O", "CF 2 CF 2 CF ₂ O", "CF _{2 CF 2} CF _{2 CF 2 O} ""," and "CF(CF ₃ ) CF ₂ O", one or more bonding units included in Rf are not particularly limited in the bonding order in Rf, and each bonding unit is bonded to each other randomly without any regularity. It may have a structure with predetermined regularity (for example, a structure in which the bonding units are alternately bonded or a block structure for each type of bonding unit). Each bonding unit within the parentheses is preferably bonded randomly. When these bonding units are randomly bonded, Rf may include a portion where bonding units of the same type are repeated consecutively, a portion where bonding units of the same type are not consecutively repeated, and the like. Further, the perfluoroalkylene group contained in each bonding unit of the structure of formula (2) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms.

When Rf has the structure represented by formula (2), it has excellent lubricity, antifouling property, ease of removing fingerprint stains, and mold releasability. Although the relationship between the structure and these effects remains unclear, the perfluoropolyether group has a flexible structure in which a rigid perfluoroalkylene group is separated by highly mobile oxygen atoms. It is presumed that this is because its surface free energy is small. It should be noted that a structure in which the compound P has phosphonate functional groups at both ends of the molecule is not preferable from the viewpoint of wear resistance, etc., since molecular mobility may be reduced.

In one embodiment, the bonding unit constituting Rf preferably does not have a _CF3 group in its side chain. For example, the structure of formula (2) preferably does not have "CF( _CF3 ) _CF2O " as a bonding unit (ie, t is 0). When the fluorine chain portion has a linear structure without a bulky CF ₃ group in the side chain, the lubricity, antifouling property, ease of removing fingerprint stains, and abrasion resistance are particularly excellent.

In formula (2), p, q, r, s, and t are each independently an integer of 0 to 100, preferably an integer of 1 to 30. In formula (2), p is preferably an integer of 1 or more, and q is an integer of 1 or more.

In formula (2), p+q+r+s+t is an integer from 10 to 100, preferably from 10 to 60.

From the viewpoint of antifouling properties, Rf preferably has a structure represented by the following general formula (2-1).
(CF ₂ O) _p (CF ₂ CF ₂ O) _q (2-1)

In the structure of formula (2-1), the bonding units in the parentheses are not particularly limited in the bonding order in Rf, and the bonding units may be bonded to each other randomly without regularity, or have a predetermined regularity. It may have a structure (for example, a structure of alternate bonding, a block structure for each type of bonding unit, etc.). Rf having the structure represented by formula (2-1) has "CF ₂ O" and "CF ₂ CF ₂ O" as bonding units, and consists only of these units.

In formula (2-1), p and q are each independently an integer of 1 to 30, preferably an integer of 5 to 25.

In formula (2-1), p+q is an integer from 10 to 50, preferably from 15 to 45. When p+q is less than 10, wear resistance, antifouling properties, and mold releasability are poor. When p+q is more than 50, the ratio of phosphonate groups present per unit molecule decreases, the adhesion to the substrate surface becomes weak, the abrasion resistance deteriorates, and the molecular weight becomes large, so that the solvent The solubility in the compound decreases, and the compatibility with other components also deteriorates.

L is a single bond, C(=O) ^NR2 , _CH2O or _CH2 . L is preferably _CH2O or _CH2 . L is more preferably CH ₂ from the viewpoint of thermal stability (heat resistance) and chemical stability.

A single bond directly connects adjacent structural units, and when L is a single bond, it becomes "-(CF ₂ ) _x -(CH ₂ ) _y -" in formula (1).

R ² in C(=O)NR ² is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, or an aryl group. The substituted or unsubstituted alkyl group having 1 to 5 carbon atoms may be a straight chain, branched or cyclic alkyl group, preferably a straight chain alkyl group. Specific examples of the unsubstituted alkyl group having 1 to 5 carbon atoms include linear alkyl groups such as methyl group, ethyl group, n-propyl group, n-butyl group, and n-pentyl group; Branched alkyl groups such as isopropyl group, isobutyl group, tert-butyl group, isopentyl group, and tert-pentyl group; cyclic alkyl groups such as cyclopropyl group, cyclobutyl group, and cyclopentyl group.

x is an integer of 1 to 2, preferably 1.

y is an integer from 1 to 4, preferably 2 or 3. In addition, since the phosphonate functional groups are bonded through phosphonate bonds (C-P) and not through phosphate bonds (C-O-P), which have small bond energy, hydrolysis is unlikely to occur, and thermal or High chemical stability.

z is an integer from 0 to 2, and is preferably 2 from the viewpoint of adhesion between the cured film and the base material.

R ¹ is a hydrocarbon group having 1 to 4 carbon atoms or SiR ³ ₃ . When compound P has a plurality of R ^1s , the plurality of R ^1s may be different from each other or may be the same. Further, a plurality of R ³ contained in SiR ³ ₃ may be different from each other or may be the same.

Examples of the hydrocarbon group having 1 to 4 carbon atoms as R ¹ include methyl group, ethyl group, n-propyl group, n-butyl group, isopropyl group, isobutyl group, tert-butyl group, cyclopropyl group, and cyclobutyl group. These are the basics. R ¹ is preferably a methyl group from the viewpoint of ease of synthesis. The hydrocarbon group having 1 to 4 carbon atoms as R ³ may be selected independently of R ¹ from the same selection as the hydrocarbon group having 1 to 4 carbon atoms as R ¹ . R ³ is preferably a methyl group from the viewpoint of ease of synthesis.

The number average molecular weight of compound P is preferably more than 1,500, more preferably more than 1,500 and 5,000 or less. If it is less than 1500, the fluorine chain is short, resulting in poor water and oil repellency and mold releasability. Moreover, when it is 5,000 or more, the content of functional groups decreases, resulting in weak adhesion and poor abrasion resistance.

<Method for producing compound P>
Compound P can be synthesized, for example, using a perfluoropolyether group-containing compound having a denaturable functional group at the end as a starting material. The perfluoropolyether group-containing compound can be produced by a known method (for example, International Publication No. 2009-008380, Japanese Patent No. 6107659). As a starting material, specifically, for example, the following perfluoropolyether group-containing compounds [1a] to [1f] can be used.
[1a] A-O-Rf-(CF ₂ ) _x -C(=O)F
[1b] A-O-Rf-(CF ₂ ) _x -C(=O)OR ⁴ (R ⁴ : Hydrocarbon having 1 to 4 carbon atoms)
[1c] A-O-Rf-(CF ₂ ) _x -C(=O)OH
[1d] A-O-Rf-(CF ₂ ) _x -CH ₂ OH
[1e] A-O-Rf-(CF ₂ ) _x -Br
[1f] A-O-Rf-(CF ₂ ) _x -I

A compound having an unsaturated group at the end can be obtained by a known method using any one of the above starting materials [1a] to [1f]. For example, the following intermediate [2d] can be obtained by reacting starting material [1d] with allyl bromide in the presence of a basic compound.
[2d] A-O-Rf-(CF ₂ ) _x -L-(CH ₂ ) _y -CH=CH ₂

A compound having a phosphonic acid ester group at the end can be obtained from intermediate [2d] by a known method. For example, the following compound [3d] can be obtained as compound P by reacting dimethyl phosphite in the presence of peroxide.
[3d] A-O-Rf-(CF ₂ ) _x -L-(CH ₂ ) _y -P(=O)(OCH ₃ ) ₂

Further, a compound [4d-1] obtained by silylating the phosphonic acid ester group of compound [3d] or a compound [4d-2] obtained by dealkylating it by a known method can be obtained as compound P.
[4d-1] A-O-Rf-(CF ₂ ) _x -L-(CH ₂ ) _y -P(=O) (OSiR ³ ) ₂
[4d-2] A-O-Rf-(CF ₂ ) _x -L-(CH ₂ ) _y -P(=O)(OH) ₂

2. Surface Treatment Agent The above compound P can be used as a component of a surface treatment agent, and the surface treatment agent according to one embodiment of the present invention is a composition containing compound P and a volatile solvent. Moreover, the compound P contained in the surface treatment agent may be used alone or in combination of two or more.

The surface treatment agent preferably contains compound P in an amount of 0.1 to 5% by mass, more preferably 0.1 to 2% by mass, based on 100% by mass of the total amount of the surface treatment agent. When the amount is 0.1% by mass or more, the film has a sufficient thickness and is excellent in initial water repellency (contact angle), weather resistance, and abrasion resistance. Further, by setting the amount to 5% by mass or less, the film thickness of the film does not become too thick, and the workability during coating and spreading is good, and the uniformity and transparency of the coating film are excellent. Additionally, the cost of surface treatment agents can be reduced.

<Volatile solvent>
The volatile solvent is not limited as long as it is a solvent in which the compound P can be dissolved, and examples thereof include fluorine-modified solvents, non-fluorine solvents, and mixed solutions thereof.

Examples of the fluorine-modified solvent include hydrofluoroether, perfluorocarbon, perfluoroalkylamine, hydrofluorocarbon, perfluoropolyether, hydrofluorochlorocarbon, hydrofluoroolefin, and fluorine-modified aromatic hydrocarbon.

Non-fluorine solvents include, for example, lower alcohols such as ethyl alcohol and isopropyl alcohol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate; hydrocarbons such as hexane, toluene, benzene, and xylene. Solvents; ethers such as diethyl ether and diisopropyl ether; and the like.

These volatile solvents may be used alone or in combination of two or more. Among these volatile solvents, from the viewpoint of solubility, wettability, etc., the volatile solvent preferably includes a fluorine-modified solvent. In one embodiment, the volatile solvent is a fluorine modified solvent.

Further, the volatile solvent may be a mixed solution of a fluorine-modified solvent and a non-fluorine solvent, and may be mixed in any ratio, if necessary. The volatile solvent may contain, for example, 50 to 100% by mass of the fluorine-modified solvent in 100% by mass of the fluorine-modified solvent and the non-fluorine solvent.

<Other ingredients>
The surface treatment agent may contain other components as long as the effects of the present invention are not impaired. Other components include, for example, a perfluoropolyether compound having no phosphonate group and a catalyst.

Examples of perfluoropolyether compounds include commercially available perfluoropolyether oils such as FOMBLIN M, FOMBLIN Y, FOMBLIN Z (manufactured by Solvay Solexis), Krytox (manufactured by DuPont), and Demnum (manufactured by Daikin Industries, Ltd.). It will be done.

The catalyst is added for the purpose of promoting the hydrolysis reaction of the phosphonate functional group or the condensation reaction between the functional group and the base material, and includes acid catalysts and basic catalysts. Examples of the acid catalyst include hydrochloric acid, nitric acid, acetic acid, sulfuric acid, phosphoric acid, sulfonic acid, methanesulfonic acid, and p-toluenesulfonic acid. Examples of the basic catalyst include sodium hydroxide and potassium hydroxide.

A surface treatment agent according to another embodiment of the present invention is a composition containing a neutralized salt of compound P and water. Compound P can be used in the surface treatment agent in the form of an aqueous solution as a neutralizing salt. For example, compound P can be used by reacting with sodium hydroxide, ammonium hydroxide, zinc sulfate, zinc acetate, zinc oxide, triethylamine, morpholine, triethanolamine, etc. to form a metal salt, amine salt, or ammonium salt. . Moreover, the neutralization salt of compound P contained in the surface treatment agent may be used alone or in combination of two or more types. Note that the aqueous solution may further contain an organic solvent, a catalyst, and other additives that are compatible with water, if necessary.

<Method for producing surface treatment agent>
The surface treatment agent can be obtained by dissolving compound P in a volatile solvent. Moreover, the surface treatment agent may be manufactured by dissolving other components such as a catalyst together with the compound P in a volatile solvent as necessary.

In another embodiment, the compound P may be obtained by dissolving the metal salt, amine salt, or ammonium salt in water.

3. Article An article according to one embodiment of the present invention includes a base material and a cured film provided on the base material. The cured film is a film obtained by curing the above-mentioned surface treatment agent. The cured film is a film that has water repellency and oil repellency. The cured film is, for example, one in which a surface treatment agent is applied to the surface of a base material and cured.

Examples of the material for the base material include inorganic materials and organic materials. Inorganic materials include metals, metal oxides, single crystal materials, stones, glasses, and composites thereof. Examples of metals include iron, iron alloys (such as stainless steel), aluminum, and aluminum alloys. Examples of the metal oxide include sapphire. Examples of organic materials include resins and the like. Examples of the resin include acrylic resin and polycarbonate resin.

The article is not particularly limited as long as the base material (surface) to be treated has a heat resistance temperature higher than the curing treatment temperature. The curing treatment temperature is, for example, a temperature for effecting the applied surface treatment agent. Examples of goods include design parts, decorations, cooking utensils, plumbing products, building materials, automobiles, precision molds, displays such as smartphones, wearable devices, and tablet devices, optical components such as eyeglass lenses and protective films, and endoscopes. These items include medical equipment such as mirrors.

<Method for manufacturing articles>
Application methods for applying the above surface treatment agent to the surface of the substrate include hand coating, nozzle flow coating, dipping, spraying, reverse coating, flow coating, spin coating, roll coating, and vacuum evaporation. Any known method such as may be employed as appropriate.

Further, a treatment (pretreatment) for improving the adhesive strength between the substrate and the cured coating can be performed on the surface of the substrate in advance. Pretreatment includes polishing, cleaning, and drying with various polishing solutions, surface modification treatment with acidic or basic solutions, primer treatment, plasma irradiation, corona discharge, high-pressure mercury lamp irradiation, etc. to generate active groups on the substrate surface. An example of this is letting people know. In particular, primer treatment is preferable because it can be performed by forming active groups on the base material, and the number of active groups on the surface to which the surface treatment agent is applied can be increased.

Next, the treatment after applying the surface treatment agent to the base material will be explained. After applying the surface treatment agent to the base material, it can be cured at room temperature or by heating at 50 to 150°C. Note that room temperature, in one embodiment, means, for example, less than 50°C (or 10 to 30°C). By heating, the phosphonate group of compound P and the bonding groups such as hydroxyl groups present on the surface of the base material are bonded more strongly than when no heat treatment is performed, thereby creating an excellent bond on the surface of the base material. A durable cured film can be formed. Heating may be performed under normal pressure, increased pressure, reduced pressure, or an inert atmosphere.

Further, the thickness of the cured film is preferably 50 nm or less, more preferably 2 to 20 nm, and even more preferably 4 to 15 nm.

If the excess remains on the substrate as a dry substance, wipe the excess with a paper towel or cloth moistened with an organic solvent or with a dry paper towel or cloth to remove the cured film. can get.

<Surface properties>
The cured film of the surface treatment agent formed on the substrate preferably has the following characteristics.

(contact angle)
Using a contact angle meter (LSE-B100W manufactured by NICK), a 2 μL droplet is generated and the contact angle with respect to the test substrate is measured. Measurements are made at five different locations on the surface, and the average value is taken as the contact angle.

The contact angle of water is preferably 110 degrees or more, more preferably 114 degrees or more, and still more preferably 115 degrees or more.

The contact angle of hexadecane is preferably 70 degrees or more, more preferably 72 degrees or more, and even more preferably 73 degrees or more.

The contact angle of oleic acid is preferably 76 degrees or more, more preferably 78 degrees or more, and still more preferably 79 degrees or more.

(Fall angle)
After dropping a 20μL droplet using a contact angle meter (NICK LSE-B100W), gradually tilt the test substrate placed horizontally to measure the relationship between the test substrate and the horizontal surface when the droplet begins to fall. Measure angles. Measurements are made at five different locations on the surface, and the average value is taken as the falling angle.

The falling angle of water is preferably 20 degrees or less, more preferably 18 degrees or less, and even more preferably 16 degrees or less.

The falling angle of hexadecane is preferably 15 degrees or less, more preferably 11 degrees or less, and even more preferably 9 degrees or less.

The falling angle of oleic acid is preferably 22 degrees or less, more preferably 21 degrees or less, and still more preferably 20 degrees or less.

Hereinafter, the present invention will be specifically explained by showing synthesis examples, working examples, and comparative examples, but the present invention is not limited to the following examples.

Phosphonate compounds 1 to 7 (also referred to as compounds [1] to [7]), which are components of the surface treatment agent used in the study, are shown below. Note that phosphonate compounds 1 to 5 and 7 were synthesized by the method shown below, and phosphonate compound 6 was a commercially available product.
Phosphonate compound 1:
_{CF3O ( CF2O ) p ( CF2CF2O} ) _{q CF2CH2OCH2CH2CH2P (} =O)( _OH ) ₂
p/q≒0.9, p+q≒25
Phosphonate compound 2:
_CF3O ( _{CF2O ) p ( CF2CF2O ) q CF2CH2CH2CH2CH2P (} =O)(OH _{) 2}
p/q≒0.9, p+q≒25
Phosphonate compound 3:
_{CF3O ( CF2O ) p ( CF2CF2O} ) _{q CF2CH2OCH2CH2CH2P (} =O)( _OH ) ₂
p/q≒0.9, p+q≒45
Phosphonate compound 4:
_{CF3O ( CF2O ) p ( CF2CF2O} ) _{q CF2CH2OCH2CH2CH2P (} =O)( _OH ) ₂
p/q≒0.9, p+q≒15
Phosphonate compound 5:
(OH) ₂ (O=)PCH ₂ CH ₂ CH ₂ OCH ₂ CF ₂ (CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ OCH ₂ CH ₂ CH ₂ P(=O) (OH) ₂
p/q≒0.9, p+q≒45
Phosphonate compound 6:
CF ₃ O (CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ O (CH ₂ CH ₂ O) _n P (=O) (OH) ₂
Mn=2,400
Phosphonate compound 7:
_{CF3CF2CF2CF2O ( CF2CF2O ) 2CF2CH2CH2CH2P} ( _{= O ) ( OH ) 2}

<Synthesis example>
Synthesis of phosphonate compound 1 (Step 1-1)
Sodium hydride (4.2 g) and meta-xylene hexafluoride (100 g) were mixed in a 0.5 L flask equipped with a stirrer, reflux condenser, thermometer, dry nitrogen inlet tube, and dropping funnel, and the mixture was placed in an ice bath. The mixture was stirred for 20 minutes. Next, alcohol represented by the following formula [1-1] (100 g) and metaxylene hexafluoride (50 g) were added dropwise, and the mixture was stirred at room temperature for 20 minutes. Next, allyl bromide (21 g) and meta-xylene hexafluoride (50 g) were added dropwise, and the mixture was reacted at room temperature for 1 hour. Next, the reaction was performed at 60°C for 1 hour, at 80°C for 1 hour, and at 100°C for 4 hours. Thereafter, the reaction product was cooled, 50 g of SV110 (fluorinated solvent manufactured by Solvay) was added, and the mixture was washed with 10 g of n-heptane and 10 g of methanol, and the lower layer was separated. This washing operation was performed four times, and the separated lower layer solvent was distilled off to obtain 101 g of a colorless transparent liquid represented by the following formula [1-2] (yield: 99%).
Compound [1-1]: CF ₃ O (CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ OH
p/q≒0.9, p+q≒25
Compound [1-2]: CF ₃ O(CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ OCH ₂ CH=CH ₂

(Step 1-2)
In a 0.2 L flask equipped with a stirrer, reflux condenser, thermometer, and dry nitrogen inlet tube, compound [1-2] (50 g), dimethyl phosphite (3.5 g), and t-butyl peroxyoctoate were added. (1.4 g) and metaxylene hexafluoride (50 g) were mixed and stirred at 80° C. for 7 hours. By distilling off the low-boiling components in the reaction solution, 47 g of a colorless transparent liquid represented by the following formula [1-3] was obtained (yield 90%).
Compound [1-3]:
CF ₃ O (CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ OCH ₂ CH ₂ CH ₂ P(O) (OCH ₃ ) ₂

(Step 1-3)
In a 0.1 L flask equipped with a stirrer, reflux condenser, thermometer, and dry nitrogen inlet tube, compound [1-3] (30 g), trimethylsilyl iodide (6.1 g), and metaxylene hexafluoride (30 g) were added. were mixed and stirred at 50°C for 7 hours. Next, 30 g of methanol was added, and the mixture was stirred at 50° C. for 7 hours. By performing the same purification operation as in (Step 1-1), 28 g of a colorless transparent liquid represented by the following formula [1] was obtained (yield 95%).
_Compound [1 _{] : CF3O (CF2O)p(CF2CF2O)qCF2CH2OCH2CH2CH2P ( O ) ( OH ) 2}

The results of the NMR measurement are as follows. Note that the structure to which each shift value corresponds is indicated by "".
Compound [1]
¹ H-NMR (CDCl ₃ , TMS, δ): 1.9-2.0 (4H, m, CF ₂ CH ₂ OCH ₂ "CH ₂ CH ₂ "P(O)(OH) ₂ ), 3.8 -3.9 (4H, _m , _CF2 " _CH2 "O" _CH2 " _CH2CH2P (O)(OH) ₂ )

Synthesis of phosphonate compound 2 (step 2-1)
In a 1 L flask equipped with a stirrer, reflux condenser, thermometer, and dry nitrogen inlet tube, alcohol represented by [1-1] (200 g), triphenylphosphine (46 g), carbon tetrabromide (58 g), Imidazole (12 g), metaxylene hexafluoride (250 g), and N,N'-dimethylformamide (250 g) were mixed and stirred at 100° C. for 24 hours. By performing the same purification operation as in (Step 1-1), 201 g of a pale yellow transparent liquid represented by the following formula [2-1] was obtained (yield 98%).
Compound [2-1]: CF ₃ O(CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ Br

(Step 2-2)
In a 0.5 L flask equipped with a stirrer, reflux condenser, thermometer, and dry nitrogen inlet tube, the compound represented by [2-1] (100 g), allyltributyltin (15 g), and azobisisobutyronitrile ( 0.73 g) and meta-xylene hexafluoride (100 g) were mixed and stirred at 90° C. for 7 hours. After performing the same purification operation as in (Step 1-1), the collected layer was treated with silica gel and concentrated to obtain 74 g of a colorless transparent liquid represented by the following formula [2-2] (yield: 75%).
Compound [2-2]: CF ₃ O(CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ CH ₂ CH=CH ₂

(Step 2-3)
Compound [2-3] represented by the following formula was synthesized using compound [2-2] as a raw material in the same manner as in (Step 1-2). (Colorless transparent liquid, yield 88%)
Compound [2-3]:
_{CF3O ( CF2O ) p} ( _{CF2CF2O ) q CF2CH2CH2CH2CH2P} (O) _{( OCH3 ) 2}

(Step 2-4)
Using Compound [2-3] as a raw material, a compound represented by the following formula was synthesized in the same manner as in (Step 1-3) (colorless transparent liquid, yield 93%).
_Compound [ _{2 ] : CF3O ( CF2O} ) _{p ( CF2CF2O} ) _{qCF2CH2CH2CH2CH2P} (O)(OH) ₂

The results of the NMR measurement are as follows. Note that the structure to which each shift value corresponds is indicated by "".
Compound [2]
^1H -NMR ( _CDCl3 , _TMS , δ): 1.8-2.0 (6H _, m, _CF2CH2 " _{CH2CH2CH2 "} P(O)(OH) ₂ ), 2.1 -2.3 (2H, m, CF ₂ "CH ₂ "CH ₂ CH ₂ CH ₂ P(O)(OH) ₂ )

Synthesis of Phosphonate Compound 3 Compound [3-1] was used as a raw material and reacted in the same manner as (Step 1-1) to (Step 1-3). Compound [3] represented by the following formula was synthesized (colorless transparent liquid, total yield 90%). The structure and purity of the obtained compound were confirmed by ¹ H-NMR measurement.
Compound [3-1]: CF ₃ O(CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ OH
p/q≒0.9, p+q≒45
_{Compound [ 3 ] :} CF3O( _{CF2O ) p ( CF2CF2O} ) _{qCF2CH2OCH2CH2CH2P} (O)(OH) ₂

Synthesis of Phosphonate Compound 4 Using compound [4-1] as a raw material, the reaction was carried out in the same manner as (Step 1-1) to (Step 1-3). Compound [4] represented by the following formula was synthesized (colorless transparent liquid, total yield 89%). The structure and purity of the obtained compound were confirmed by ¹ H-NMR measurement.
Compound [4-1]: CF ₃ O(CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ OH
p/q≒0.9, p+q≒15
_Compound [4 _{] : CF3O (CF2O)p(CF2CF2O)qCF2CH2OCH2CH2CH2P ( O ) ( OH ) 2}

Synthesis of Phosphonate Compound 5 Compound [5-1] was used as a raw material and reacted in the same manner as (Step 1-1) to (Step 1-3). Compound [5] represented by the following formula was synthesized (colorless transparent liquid, total yield 86%). The structure and purity of the obtained compound were confirmed by ¹ H-NMR measurement.
Compound [5-1]: HOCH ₂ CF ₂ (CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ OH
p/q≒0.9, p+q≒45
Compound [5]: (OH) ₂ (O=) PCH ₂ CH ₂ CH ₂ OCH ₂ CF ₂ (CF ₂ O) _p (CF ₂ CF ₂ O) _q CF ₂ CH ₂ OCH ₂ CH ₂ CH ₂ P(= O) (OH) ₂

Synthesis of Phosphonate Compound 7 Using compound [7-1] as a raw material, the reaction was carried out in the same manner as (Step 2-2) to (Step 2-4). Compound [7] represented by the following formula was synthesized (colorless transparent liquid, total yield 81%). The structure and purity of the obtained compound were confirmed by ¹ H-NMR measurement.
Compound [7-1]: CF ₃ CF ₂ CF ₂ CF ₂ O(CF ₂ CF ₂ O) ₂ CF ₂ Br
_{Compound [ 7 ] : CF3CF2CF2CF2O} ( _{CF2CF2O ) 2CF2CH2CH2CH2P} (O) ₍ OH _{) 2}

<Preparation of surface treatment agent>
By mixing 0.5 g of each phosphonate compound and 99.5 g of Novec 7200 (fluorinated solvent manufactured by 3M) and stirring thoroughly, 0.5% by mass of the active ingredient is contained based on 100% by mass of the total amount of surface treatment agent. Surface treatment agents 1 to 7 were obtained.

<Preparation of test board>
Each test piece of a stainless steel plate (SUS304, 26 mm x 76 mm) was immersed in normal heptane and subjected to ultrasonic treatment (5 minutes). After that, the same operation was performed using acetone. Next, the test piece was subjected to VUV treatment (λ _max =254 nm, gap 2 mm, 6 times). The test piece was dip-coated with a surface treatment agent (pulling speed: 10 mm/s). Finally, test substrates 1 to 7 having cured films were obtained by heating and curing at 100° C. for 1 hour.

<Evaluation of test substrates using each surface treatment agent>
The cured films of test substrates 1 to 7 were evaluated by the following tests (1) to (7). Each test was conducted on the surface-treated side of the test substrate.

(1) Contact angle measurement (water/oil repellency test)
A 2 μL droplet was generated using a contact angle meter (LSE-B100W manufactured by NICK), and the contact angle with respect to the test substrate was measured. Measurements were performed at five different locations on the surface, and the average value is shown. Water, hexadecane, and oleic acid were used as droplets.

(2) Falling angle measurement (water repellency/oil repellency test)
After dropping a 20μL droplet using a contact angle meter (NICK LSE-B100W), gradually tilt the test substrate placed horizontally to measure the relationship between the test substrate and the horizontal surface when the droplet begins to fall. The angle (falling angle) was measured. Measurements were performed at five different locations on the surface, and the average value is shown. Water, hexadecane, and oleic acid were used as droplets.

(3) Pen writing test (antifouling test)
Writing was performed on the test board using an oil-based marking pen (product name: Mackie, manufactured by Zebra Corporation), and the ink repellency was visually judged. The evaluation criteria were the following six levels.
1: Repels ink well 2: Repels ink but has slow aggregation speed 3: Repels ink weakly 4: Repels ink poorly and has slow aggregation speed 5: Does not repel ink much, leaving ink streaks 6: Ink don't play at all

(4) Abrasion resistance test A nonwoven fabric (Bemcot) was attached to an abrasion resistance tester (API-3DT manufactured by API Corporation), and the test board was slid at a speed of 40 mm x 60 reciprocations/min under a load of 1 kgf/cm ² . The contact angle of water was measured in the same manner as in "(1) Contact angle measurement" after every 1000 reciprocations, and the test was conducted until the contact angle was less than 100 degrees or the number of sliding movements reached 10,000 reciprocations. .

(5) Heat resistance test The test substrate was exposed in a constant temperature bath (WFO-420, manufactured by Tokyo Rikakikai Co., Ltd.) set at 200°C. After every 24 hours, the substrate was taken out, and after being left to cool, the surface of the test substrate was rinsed with Asahiklin AK-225 (fluorinated solvent manufactured by AGC), and the contact angle of water was measured in the same manner as in "(1) Contact angle measurement" above. did. Testing was conducted until the contact angle was below 100 degrees or the exposure time reached 200 hours.

(6) Friction test (lubricity test)
An ABS ball (1 cm ³ ) was attached to a surface property measuring machine (Type: 14FW, manufactured by Shinto Kagaku Co., Ltd.), and the test board was slid 1 cm at a speed of 500 mm/min under a load of 100 gf to measure the coefficient of dynamic friction.

(7) Mold releasability/mold release durability test Apply an epoxy adhesive (manufactured by Toagosei; one-component curing epoxy resin AP-0021HW) to the test substrate, and use a hook-shaped jig (cross-sectional area: 1 cm ² ) was posted. The adhesive was cured by heating at 100° C. for 30 minutes. Next, the metal substrate was fixed on a tensile tester (Desktop tensile compression tester MCT-2150 manufactured by A&D), and the hook was pulled up in a 90° direction at a speed of 60 mm/min. The mold release load at this time was defined as the mold releasability, and evaluation was made based on the following evaluation criteria (A and B were passed, and C was judged as failure). By repeating the above series of operations and forming a cured film by applying the surface treatment agent once, measure how many times the mold can be released under a mold release load condition of less than 50N, and calculate the number of times the mold can be released. This was used as an index of mold durability.
A: Less than 1N B: 1N or more, less than 10N C: 10N or more

Table 1 shows the evaluation results of surface characteristics for each example and each comparative example.

From the results in Table 1, the test substrates treated with surface treatment agents using phosphonate compounds 1 to 4 showed excellent water and oil repellency, abrasion resistance, stain resistance, lubricity, ease of fingerprint stain removal, heat resistance, and mold release. Good results were obtained in both properties and mold release durability. In addition, these had a small coefficient of dynamic friction.

The test substrate treated with the surface treatment agent using phosphonate compound 5 had insufficient water and oil repellency, as well as poor abrasion resistance and lubricity. This is presumably because the molecular mobility of the perfluoropolyether chain was restricted due to the presence of phosphonate functional groups at both ends of the molecule.

The test substrate treated with the surface treatment agent using phosphonate compound 6 had insufficient heat resistance and poor mold release durability. This is presumed to be because the bond energy of the phosphate ester bond (C--O--P) between the perfluoropolyether group and the phosphonate functional group and the ether bond in the ethylene oxide chain is weak.

The test substrate treated with the surface treatment agent using Phosphonate Compound 7 had poor abrasion resistance, antifouling properties, lubricity, and mold releasability. This is presumed to be because the molecular weight of the perfluoropolyether group is small and the function of the perfluoropolyether group is not fully exhibited.

Possibility of industrial use

Articles treated with the surface treatment agent of the present invention have excellent water and oil repellency, abrasion resistance, antifouling properties, mold releasability, lubricity, ease of removing fingerprint stains, and heat resistance. Due to these characteristics, it is used in design parts, decorative items, cooking utensils, plumbing products, building materials, automobiles, precision molds, displays such as smartphones, wearable devices, and tablet devices, optical components such as eyeglass lenses and protective films, and endoscopes. It can be used as a surface treatment agent for articles such as medical devices such as mirrors.

Claims (6)

A surface treatment agent comprising a perfluoropolyether group-containing phosphonate compound represented by the following general formula (1) and a volatile solvent ,
A-O-Rf-(CF ₂ ) _x -L-(CH ₂ ) _y -P(=O )( OH) ₂ (1)
In the general formula (1),
A is a perfluoroalkyl group having 1 to 4 carbon atoms,
Rf has a structure represented by the following general formula (2), and each bonding unit in parentheses may be randomly bonded,
(CF ₂ O) _p (CF ₂ CF ₂ O) _q (CF ₂ CF ₂ CF ₂ O) _r (2)
In the general formula (2),
p, q , are each independently an integer of 1 to 100, r is an integer of 0 to 100, p+q+ r is an integer of 10 to 100,
L is a single bond , C H ₂ O or CH ₂ ,
x is an integer from 1 to 2,
y is an integer from 1 to 4,
Surface treatment agent . In the general formula (1),
A is ₃ CF groups,
Rf has a structure represented by the following general formula (2-1), and each bonding unit in parentheses may be randomly bonded,
(CF ₂ O) _p (CF ₂ CF ₂ O) _q (2-1)
L is _CH2O or _CH2 ,
In the general formula (2-1) , p and q are each independently an integer of 1 to 30,
p+q is an integer from 10 to 50,
The surface treatment agent according to claim 1. The surface treatment agent according to claim 1, having a number average molecular weight of more than 1,500. An article comprising a base material and a cured film of the surface treatment agent according to any one of claims 1 to 3 on the surface of the base material. 5. The article according to claim 4 , wherein the substrate is metal. 5. The article of claim 4 , wherein the substrate is a metal oxide.