WO2025057528A1 - Perfluoropolyether phosphate ester or salt thereof, surface treatment agent, coating agent, mold release agent, and method for producing perfluoropolyether phosphate ester or salt thereof - Google Patents

Abstract

The present invention relates to a perfluoropolyether phosphate ester represented by general formula (1) or a perfluoropolyether phosphate ester salt represented by general formula (2). (In general formulae (1) and (2), n is an integer of 1-20, M₁ is an alkali metal, an ammonium base, or an organic amine base, and M₂ is a hydrogen atom, an alkali metal, an ammonium base, or an organic amine base.)

Description

Perfluoropolyether phosphate or its salt, surface treatment agent, coating agent, release agent, and method for producing perfluoropolyether phosphate or its salt

The present invention relates to perfluoropolyether phosphate esters or their salts, surface treatment agents, coating agents, release agents, and methods for producing perfluoropolyether phosphate esters or their salts.

Fluoroalkylphosphonic acid is used as a raw material for surface treatment agents. Compounds in which the perfluoroalkyl group has 8 to 12 carbon atoms are most likely to exhibit surface treatment performance, and in particular, telomer compounds with 8 carbon atoms and the structural formula _CF3 ( _{CF2 ) 7CH2CH2} - _P (O)(OH) ₂ are widely used as active ingredients in surface treatment agents (see Patent Documents 1 to 4).

On the other hand, it has been reported that telomer compounds with perfluoroalkyl groups with 8 to 12 carbon atoms are biodegraded in the environment and turn into compounds with relatively high bioaccumulation and environmental concentration, raising concerns about exposure during the treatment process, release into the environment from waste materials and treatment substrates, and diffusion. On the other hand, compounds with perfluoroalkyl groups with 14 or more carbon atoms are very difficult to handle due to their physical and chemical properties, and are therefore rarely used in practice.

Furthermore, in the production process of telomer compounds having a perfluoroalkyl group with 8 or more carbon atoms, the generation or contamination of highly bioaccumulative perfluorooctanoic acids is unavoidable. For this reason, in recent years, the use of telomer compounds having 8 carbon atoms has been restricted, and they are being replaced by compounds having a perfluoroalkyl group with 6 or less carbon atoms, for example, telomer compounds having ₆ carbon atoms and the structural formula _CF3 ( _CF2 ) _5CH2CH2 - _P (O)(OH) ₂ .

However, when compounds with a perfluoroalkyl group containing six or fewer carbon atoms are used as surface treatment agents, the orientation on the surface of the target substrate is significantly reduced, and the melting point, glass transition point (Tg), etc. are significantly lower than those of compounds with a perfluoroalkyl group containing eight carbon atoms, so they are significantly affected by the environmental conditions of use, such as temperature, humidity, stress, and organic solvents. As a result, such surface treatment agents do not provide the sufficient performance required, and durability, etc. are also affected.

Compounds containing perfluoropolyether groups have extremely low surface energy and therefore have properties such as water and oil repellency, chemical resistance, lubricity, release properties, and stain resistance. Taking advantage of these properties, compounds containing perfluoropolyether groups are widely used industrially as oil repellents for equipment, release agents, cosmetics, protective films, and the like.

Special Publication No. 2-45572 Special Publication No. 3-78244 Special Publication No. 4-4923 Special Publication No. 4-11366

The object of the present invention is to provide a perfluoropolyether phosphate ester or a salt thereof that can impart excellent oil repellency, durability, and releasability to a substrate, as well as a method for producing the same.

(上記一般式（１）中、ｎは１～２０の整数である。) The perfluoropolyether phosphate according to this embodiment is a perfluoropolyether phosphate represented by the following general formula (1).

(In the above general formula (1), n is an integer from 1 to 20.)

(上記一般式（２）中、ｎは１～２０の整数であり
Ｍ_１はアルカリ金属、アンモニウム塩基または有機アミン塩基であり、
Ｍ_２は水素原子、アルカリ金属、アンモニウム塩基または有機アミン塩基である。) The perfluoropolyether phosphate salt according to this embodiment is a perfluoropolyether phosphate salt represented by the following general formula (2).

(In the above general formula (2), n is an integer of 1 to 20, and _M1 is an alkali metal, an ammonium base, or an organic amine base;
_M2 is a hydrogen atom, an alkali metal, an ammonium base, or an organic amine base.

(上記一般式（４）中、ｎは１～２０の整数である)をオキシ塩化リンの存在下で反応させる工程と、
　ｂ）工程ａ）で得られた一般式（５）で表される化合物

(上記一般式（５）中、ｎは１～２０の整数である)を加水分解する工程と、
　ｃ）任意に、工程ｂ）で得られたパーフルオロポリエーテルリン酸エステルを中和する工程と、
を含み、
　前記パーフルオロポリエーテルアルコールに対する前記オキシ塩化リンの当量比が、モル比換算で１０以上２０以下である。 The method for producing a perfluoropolyether phosphate ester or a salt thereof according to the present embodiment includes the steps of:
a) Perfluoropolyether alcohol represented by general formula (4)

(wherein n is an integer of 1 to 20) in the presence of phosphorus oxychloride;
b) The compound represented by formula (5) obtained in step a)

(wherein n is an integer of 1 to 20)
c) optionally neutralizing the perfluoropolyether phosphate ester obtained in step b);
Including,
The equivalent ratio of the phosphorus oxychloride to the perfluoropolyether alcohol is 10 or more and 20 or less in terms of molar ratio.

The present invention provides a perfluoropolyether phosphate ester or a salt thereof that can impart excellent oil repellency, durability, and releasability to a substrate, as well as a method for producing the same.

<Perfluoropolyether phosphate ester or its salt>
Hereinafter, the embodiment of the present invention will be described in detail. The perfluoropolyether phosphate of the present invention is represented by the following general formula (1), and is a perfluoropolyether phosphate having one perfluoropolyether (PFPE) chain. Such perfluoropolyether phosphate has improved hydrophilicity compared to two-chain perfluoropolyether phosphate having two hydrophobic PFPE chains, and can be dispersed in water without using organic solvents, and the burden on the environment can be reduced. In addition, when this dispersion is applied to various substrate surfaces, such as metal surfaces, the number of hydroxyl groups on the phosphorus atom coordinated on the metal surface increases from one to two, so that the hydroxyl groups are more firmly bonded on the metal surface. Therefore, the durability of the film obtained by coating and curing the perfluoropolyether phosphate on a substrate is improved.

In general formula (1), n is an integer from 1 to 20, preferably from 1 to 10, and more preferably from 2 to 6.

The perfluoropolyether phosphate ester of the present invention may be in the form of a salt from the viewpoint of workability. Such a perfluoropolyether phosphate ester salt is represented by the following general formula (2).

In general formula (2), n is an integer of 1 to 20, preferably 1 to 10, and more preferably 2 to 6. Furthermore, _M1 is an alkali metal, an ammonium base, or an organic amine base, and _M2 is a hydrogen atom, an alkali metal, an ammonium base, or an organic amine base. When _M1 and _M2 are an alkali metal, an ammonium base, or an organic amine base, they may be the same or different.

In _M1 and _M2 , examples of the alkali metal include sodium (Na), potassium (K), and lithium (Li). Examples of the ammonium base include _NH4 ⁺ , ammonium salts substituted with an alkyl group such as monoethyl, monoisopropyl, diethyl, dicyclohexyl, and triethyl, or a cycloalkyl group having 3 to 7 carbon atoms, and ammonium salts substituted with a hydroxyalkyl group such as monoethanol, diethanol, triethanol, and diisopropanol. Examples of the organic amine base include pyridine, DMAP (4-dimethylaminopyridine), DBU (diazabicycloundecene), DBN (diazabicyclononene), imidazole, and polyalkoxyalkylamine.

In addition to the durability described above, the perfluoropolyether phosphate ester or its salt of the present invention exhibits excellent oil repellency when applied to the surface of various substrates, preferably metal surfaces, and the oil repellency does not decrease significantly even after durability tests. Furthermore, the release load is small and excellent release properties are observed in the release of a resin molded product from a mold coated with a solution containing the perfluoropolyether phosphate ester or its salt of the present invention. Therefore, the perfluoropolyether phosphate ester or its salt of the present invention can be used as an active ingredient in a surface treatment agent or a release agent. Furthermore, the perfluoropolyether phosphate ester is also effective as a coating agent because the film formed by coating and curing the perfluoropolyether phosphate ester on a substrate has good durability.

The perfluoropolyether phosphate ester or its salt contained in the surface treatment agent, release agent or coating agent may be diluted with an organic solvent for use from the viewpoint of economy and workability. Examples of such organic solvents include fluorine-containing organic solvents such as alcohols such as methanol, ethanol, n-propanol, and isopropanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, dioxane, and tetrahydrofuran; esters such as ethyl acetate and butyl acetate; polyhydric alcohol derivatives such as methyl cellosolve, ethyl cellosolve, methyl carbitol, and ethyl carbitol; and halogenated hydrocarbons such as carbon tetrachloride, methylene chloride, trichloroethylene, perchloroethylene, trichloroethane, trichlorofluoromethane, tetrachlorodifluoroethane, and trichlorotrifluoroethane. Among these, fluorine-containing organic solvents are preferred as the organic solvent. Examples of commercially available fluorine-containing organic solvents include "NOVEC 7200" (manufactured by 3M), "NOVEC 7300" (manufactured by 3M), and "AE-3000" (manufactured by AGC).

On the other hand, since perfluoropolyether phosphate ester or its salt can be dispersed in water, from the viewpoints of economy, workability, and furthermore, environmental friendliness, the surface treatment agent, release agent or coating agent, particularly the release agent, may contain water and preferably does not contain an organic solvent. Examples of such organic solvents include the organic solvents mentioned above.

　Surface treatment agents, release agents or coating agents containing perfluoropolyether phosphate esters or their salts are prepared by diluting with an organic solvent, water or a mixture thereof to give a solution with a solids concentration of 0.01% by weight or more and 30% by weight or less, preferably 0.03% by weight or more and 3% by weight or less.

In addition, when water is used as a solvent for the surface treatment agent, release agent, or coating agent, it is preferable that the dispersion containing the perfluoropolyether phosphate ester or its salt and water further contains an organic amine represented by the following general formula (3). By using an organic amine represented by general formula (3) for a perfluoropolyether phosphate ester or its salt having a single PFPE chain, it is possible to prepare a surface treatment agent, release agent, or coating agent that can be dispersed in water alone without using an organic solvent.

R ₁ -N-(R ₂ ) ₂ (3)

In general formula (3), _R1 is an alkyl group having 1 to 40 carbon atoms, preferably an alkyl group having 5 to 30 carbon atoms, and more preferably an alkyl group having 12 to 24 carbon atoms. The alkyl group may be linear or branched.

R ₂ is represented by -(C _a H _2a O) _b -R _3. a is an integer of 1 to 22, b is an integer of 1 to 100, and R ₃ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. a is preferably an integer of 1 to 10, and more preferably an integer of 2 to 3. b is preferably an integer of 1 to 100, and more preferably an integer of 1 to 30. When R ₃ is a hydrocarbon alkyl group having 1 to 12 carbon atoms, the alkyl group may be linear or branched. R ₃ is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms.

Such organic amines include, for example, higher aliphatic amine derivatives such as polyoxyethylene stearylamine, polyoxyethylene oleylamine, and polyoxyethylene laurylamine.

The surface treatment agent, release agent or coating agent may contain various surfactants, such as ionic or nonionic surfactants, to improve wettability, silicone oil or silicone varnish to improve lubricity, etc., as necessary.

Substrates that can be treated with the above-mentioned surface treatment agents, release agents, or coating agents include substrates made of various materials such as metals and their oxides, porcelain, ceramics, resins, plastics, glass, and rubber. Specifically, substrates for surface treatment agents and coating agents include molded products such as metals, metal oxides, and ceramics, while substrates for release agents include molds and molded products made of resins and rubber. The thickness of the cured coating formed on the surface of the above-mentioned various substrates is not particularly limited and is selected appropriately depending on the type of substrate.

<Method of producing perfluoropolyether phosphate or its salt>
The perfluoropolyether phosphate ester in the present invention is produced by reacting a perfluoropolyether alcohol having a specific structure in the presence of phosphorus oxychloride, and hydrolyzing the compound obtained.In addition, in the reaction between perfluoropolyether alcohol and phosphorus oxychloride, phosphorus oxychloride is used in a large excess relative to the perfluoropolyether alcohol.Specifically, phosphorus oxychloride is used in an amount of 10 equivalents or more and 20 equivalents or less in terms of molar ratio relative to the perfluoropolyether alcohol.Therefore, the chloride of perfluoropolyether phosphoric acid having one PFPE chain is selectively synthesized rather than the chloride of perfluoropolyether phosphoric acid having two PFPE chains, and the perfluoropolyether phosphate ester represented by the above general formula (1) can be obtained by neutralizing the obtained perfluoropolyether phosphate ester represented by the general formula (1), and the perfluoropolyether phosphate ester salt represented by the above general formula (2) can be formed.

The method for producing a perfluoropolyether phosphate ester or a salt thereof of the present invention includes the steps of: a) reacting a perfluoropolyether alcohol represented by the following general formula (4) in the presence of phosphorus oxychloride; b) hydrolyzing the compound represented by general formula (5) obtained in step a); and c) optionally neutralizing the perfluoropolyether phosphate ester obtained in step b). Each step will be described in detail below.

(Perfluoropolyether alcohol)
In step a), a perfluoropolyether alcohol represented by the following general formula (4) is used as a raw material. Such perfluoropolyether alcohol has a hydroxyl group at the end of the molecule, and this hydroxyl group reacts with phosphorus oxychloride to synthesize a perfluoropolyether phosphate chloride.

In general formula (4), n is an integer from 1 to 20, preferably from 1 to 10, and more preferably from 2 to 6.

(Phosphorus oxychloride)
In step a), phosphorus oxychloride is used so that the equivalent ratio of phosphorus oxychloride to perfluoropolyether alcohol is 10 to 20 in molar ratio, and reacted with the perfluoropolyether alcohol represented by the above general formula (4). The equivalent ratio of phosphorus oxychloride to perfluoropolyether alcohol (in terms of moles) is preferably 13 to 18, more preferably 15 to 17.

In step a), perfluoropolyether alcohol is reacted in the presence of phosphorus oxychloride at a temperature of 100°C to 120°C for 10 to 30 hours. Next, low boiling points are removed under reduced pressure at an internal temperature of 90°C to 110°C, and then the mixture is distilled under reduced pressure to form a specified chloride of perfluoropolyether phosphate ester. In addition, calcium chloride, which is a dehydrating agent, does not have to be used in step a).

In step b), the compound represented by the following general formula (5) obtained in step a) is hydrolyzed to form the perfluoropolyether phosphate represented by the above general formula (1). Water is slowly added dropwise to the compound represented by general formula (5) so that the internal temperature does not exceed 60°C, and the hydrolysis reaction is initiated. Water is then removed from the resulting reaction mixture under reduced pressure to obtain the perfluoropolyether phosphate represented by general formula (1).

In general formula (5), n is an integer from 1 to 20, preferably from 1 to 10, and more preferably from 2 to 6.

In step c), the perfluoropolyether phosphate ester represented by general formula (1) obtained in step b) can be optionally neutralized to form a perfluoropolyether phosphate ester salt represented by general formula (2). The salt is generally formed by titrating the perfluoropolyether phosphate ester represented by general formula (1) with a salt-forming reactant such as sodium hydroxide, ammonium hydroxide, triethylamine, morpholine, triethanolamine, or tris(2-hydroxyethyl) while checking the equivalence point with pH. This forms a monovalent alkali metal salt, ammonium salt, or organic amine salt as shown in the perfluoropolyether phosphate ester salt represented by general formula (2).

(上記一般式（１）中、ｎは１～２０の整数である。)
［２］
　一般式（２）で表されるパーフルオロポリエーテルリン酸エステル塩。

(上記一般式（２）中、ｎは１～２０の整数であり
Ｍ_１はアルカリ金属、アンモニウム塩基または有機アミン塩基であり、
Ｍ_２は水素原子、アルカリ金属、アンモニウム塩基または有機アミン塩基である。)
［３］
　上記［１］に記載のパーフルオロポリエーテルリン酸エステル又は上記［２］に記載のパーフルオロポリエーテルリン酸エステル塩を含む表面処理剤。
［４］
　上記［１］に記載のパーフルオロポリエーテルリン酸エステル又は上記［２］に記載のパーフルオロポリエーテルリン酸エステル塩を含むコーティング剤。
［５］
　上記［１］に記載のパーフルオロポリエーテルリン酸エステル又は上記［２］に記載のパーフルオロポリエーテルリン酸エステル塩を含む離型剤。
［６］
　さらに水を含む上記［４］に記載の離型剤。
［７］
　さらに一般式（３）で表される有機アミンを含む上記［６］に記載の離型剤。
　　　Ｒ_１－Ｎ－（Ｒ_２）_２　　　（３）
（上記一般式（３）中、Ｒ_１は炭素数１～２２のアルキル基であり、Ｒ_２は－（Ｃ_ａＨ_２ａＯ）_ｂ－Ｒ_３で表され、
ａは１～２２の整数であり、
ｂは１～１００の整数であり、
Ｒ_３は水素原子または炭素数１～１２のアルキル基である。）
［８］
　ａ）一般式（４）で表されるパーフルオロポリエーテルアルコール

(上記一般式（４）中、ｎは１～２０の整数である)をオキシ塩化リンの存在下で反応させる工程と、
　ｂ）工程ａ）で得られた一般式（５）で表される化合物

(上記一般式（５）中、ｎは１～２０の整数である)を加水分解する工程と、
　ｃ）任意に、工程ｂ）で得られたパーフルオロポリエーテルリン酸エステルを中和する工程と、
を含む、パーフルオロポリエーテルリン酸エステル又はその塩の製造方法であって、
　前記パーフルオロポリエーテルアルコールに対する前記オキシ塩化リンの当量比が、モル比換算で１０以上２０以下であることを特徴とする、前記製造方法。
［９］
　前記工程ａ）において、塩化カルシウムを使用しない、上記［８］に記載の製造方法。 Based on the above-mentioned embodiments, the present invention relates to the following [1] to [8].
[1]
A perfluoropolyether phosphate ester represented by general formula (1):

(In the above general formula (1), n is an integer from 1 to 20.)
[2]
A perfluoropolyether phosphate salt represented by general formula (2):

(In the above general formula (2), n is an integer of 1 to 20, and _M1 is an alkali metal, an ammonium base, or an organic amine base;
_M2 is a hydrogen atom, an alkali metal, an ammonium base, or an organic amine base.
[3]
A surface treatment agent comprising the perfluoropolyether phosphate ester according to the above [1] or the perfluoropolyether phosphate salt according to the above [2].
[4]
A coating agent comprising the perfluoropolyether phosphate ester according to the above [1] or the perfluoropolyether phosphate salt according to the above [2].
[5]
A release agent comprising the perfluoropolyether phosphate ester according to the above item [1] or the perfluoropolyether phosphate salt according to the above item [2].
[6]
The release agent according to the above item [4], further comprising water.
[7]
The release agent according to the above item [6], further comprising an organic amine represented by general formula (3).
R ₁ -N-(R ₂ ) ₂ (3)
(In the above general formula (3), R ₁ is an alkyl group having 1 to 22 carbon atoms, and R ₂ is represented by -(C _a H _{2 a} O) _b -R ₃ ;
a is an integer from 1 to 22;
b is an integer from 1 to 100;
_R3 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.
[8]
a) Perfluoropolyether alcohol represented by general formula (4)

(wherein n is an integer of 1 to 20) in the presence of phosphorus oxychloride;
b) The compound represented by formula (5) obtained in step a)

(wherein n is an integer of 1 to 20)
c) optionally neutralizing the perfluoropolyether phosphate ester obtained in step b);
A method for producing a perfluoropolyether phosphate ester or a salt thereof, comprising:
The above-mentioned production method is characterized in that an equivalent ratio of the phosphorus oxychloride to the perfluoropolyether alcohol is 10 or more and 20 or less in terms of a molar ratio.
[9]
The method according to the above-mentioned [8], wherein calcium chloride is not used in the step a).

The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment, and includes all aspects included in the concept of the present invention and the scope of the claims, and can be modified in various ways within the scope of the present invention.

Below, examples of the present invention are described, but the present invention is not limited to these examples as long as they do not deviate from the spirit of the invention. Also, unless otherwise specified, room temperature is within the range of 20°C ± 5°C.

Example 1
A 2L flask was charged with 1226g (about 8.0 moles) of phosphorus oxychloride and stirred, and then 500g (about 0.51 moles) of perfluoropolyether alcohol (PO-6-OH) having the following structural formula was added, and the temperature was raised to 110°C, followed by stirring for 24 hours. ^1H -NMR confirmed that PO-6-OH had disappeared, and the reaction was terminated. Next, low boiling points were removed at an internal temperature of 90 to 110°C under a reduced pressure of 4.5kPa, and the reduced pressure was reduced to 0.1KPa, and the mixture was distilled under reduced pressure at an internal temperature of 160°C to obtain 468.9g (yield 85%) of perfluoropolyether phosphoric acid chloride having the following structural formula with a purity of 99.2GC% (PO-6-PAECl).

Then, 468.9 g of the obtained PO-6-PAECl was charged into a flask with a capacity of 1 L, and 3.9 g of water was slowly dropped so that the internal temperature did not exceed 60°C, and the mixture was stirred for 24 hours. The disappearance of PO-6-PAECl was confirmed by ¹ H-NMR, and the reaction was terminated. Next, dehydration was performed under a reduced pressure of 0.1 kPa at an internal temperature of 50°C, and 404.4 g of a transparent liquid (yield 90%) was obtained. The obtained liquid was subjected to ¹ H-NMR and ¹⁹ F-NMR measurements and spectrum analysis, and it was found that the obtained liquid was a perfluoropolyether phosphate ester (PO-6-PAE) having the following structural formula, which was the target product.

^1H NMR (CDCl ₃ , TMS): ppm 4.4ppm (CFC H ₂ )
10.9 ppm ( OH )
^19F NMR (CDCl ₃ , C ₆ F ₆ ): ppm -85.3ppm ( CF ₃ )
-83.0～-85.3ppm(CF ₃ CF ₂ CF ₂ )
-83.0～-85.3ppm CH ₂ CFCF ₃ (OCF ₂ CF CF ₃ )
-83.0～-85.3ppm CH ₂ CFCF ₃ (O CF ₂ CFCF ₃ )
-83.0～-85.3ppm CH ₂ CF CF3 (OCF ₂ CFCF ₃ )
-132.8ppm _{( CF3CF2} )
-137.6ppm CH ₂ CF CF ₃ (OCF ₂ CFCF ₃ )
-147.5ppm CH ₂ CFCF ₃ (OCF ₂ CF CF ₃ )

Example 2
A 500 mL flask was charged with 215 g (about 1.4 mol) of phosphorus oxychloride and stirred, and then 124 g (about 0.085 mol) of perfluoropolyether alcohol (PO-L-OH) having the following structural formula was added, and the temperature was raised to 110° C. and stirred for 24 hours. The disappearance of PO-L-OH was confirmed by ¹ H-NMR, and the reaction was terminated. Next, low boiling points were removed at an internal temperature of 90 to 110° C. under a reduced pressure of 4.5 kPa, and then the reduced pressure was reduced to 0.1 KPa and the internal temperature was distilled under reduced pressure at 100° C. to obtain 127 g (78% yield) of perfluoropolyether phosphoric acid chloride (PO-L-PAECl) having the following structural formula.

Then, 127 g of the obtained PO-L-PAECl was charged into a flask with a capacity of 200 mL, and 3.9 g of water was slowly dropped so that the internal temperature did not exceed 60 ° C., and vigorously stirred at an internal temperature of 50 ° C. for 24 hours. The disappearance of PO-L-PAECl was confirmed by ¹ H-NMR, and the reaction was terminated. Next, dehydration was performed under reduced pressure of 0.1 kPa at an internal temperature of 50 ° C. to obtain 94 g of a brown opaque liquid (yield 77%). The obtained liquid was subjected to ¹ H-NMR and ¹⁹ F-NMR measurement, and spectrum analysis was performed. The spectrum assignment was the same as that of PO-6-PAE, and the obtained viscous liquid was the target product, a perfluoropolyether phosphate ester (PO-L-PAE) having the following structural formula.

[Contact angle test]
Example 3
0.5 g of the PO-6-PAE obtained in Example 1 was added to 99.5 g of a fluorine-containing organic solvent ("NOVEC 7200", manufactured by 3M Corporation) and stirred for about 30 minutes to prepare Preparation Liquid A-1.

A chrome-plated copper plate test piece (25×75×1.2 mm) was dip-coated in this Preparation Solution A-1 under conditions of an immersion time of 5 seconds and a pull-up speed of 2 mm/sec, and baked at 150° C. for 1 hour. The contact angle of the resulting coating film was measured to evaluate the oil repellency and durability. The oil repellency was evaluated by the static contact angle of the resulting coating film using hexadecane, and the durability was evaluated by applying a load of 20 g/cm ² to the coating film using a 100% cotton cloth, sliding it 2000 times, and then measuring the static contact angle using hexadecane. The results are shown in Table 1.

Example 4
The same procedure as in Example 3 was carried out except that Preparation Solution A-2 was prepared using PO-L-PAE obtained in Example 2 instead of PO-6-PAE, and the contact angle of the coating film obtained using this was measured to evaluate the oil repellency and durability. The results are shown in Table 1.

<Comparative Example 1>
The same operations as in Example 3 were carried out except that Preparation Solution A-3 was prepared using a perfluoropolyether phosphate ester (R _f C ₆ -PAE) having the following structural formula instead of PO-6-PAE, and the contact angle of the coating film obtained using this was measured to evaluate the oil repellency and durability. The results are shown in Table 1. Note that R _f C ₆ -PAE contains perfluoropolyether phosphate ester with m=2:perfluoropolyether phosphate ester with m=1 in a ratio of 100:0 to 20:80.

As shown in Table 1, in Examples 3 and 4, the coating film obtained had a high initial contact angle of 73°, excellent oil repellency, and excellent durability, as the oil repellency did not decrease significantly even after the durability test. On the other hand, in Comparative Example 1, the coating film obtained had an initial contact angle of about 60°, lower oil repellency than Examples 3 and 4, and the oil repellency decreased significantly after the durability test.

[Release test]
Example 5
To 0.1 g of PO-6-PAE obtained in Example 1, 65 g of isopropanol and 34.7 g of water were added, and then 0.2 g of triethylamine was added with stirring, followed by stirring for about 30 minutes to prepare release agent B-1.

　The release agent B-1 was sprayed onto the inside of a SUS mold (diameter 45 mm, depth 50 mm) and dried at 120°C for 5 minutes. 100 parts by weight of polyurethane prepolymer ("Coronate C-4090", manufactured by Nippon Polyurethane Co., Ltd.) heated to 80°C and 12.8 parts by weight of a heat-melted hardener (methylene bis-o-chloroaniline: "Iharacamine MT", manufactured by Ihara Chemical Co., Ltd.) were mixed and stirred while being careful not to trap air bubbles to produce a prepolymer mixture. Next, this prepolymer mixture was poured into a SUS mold coated with the release agent B-1 and heated at 120°C for 1 hour to harden it, forming a polyurethane molded product. After that, a hook that had been installed in advance to remove the polyurethane molded product formed in the center of the mold cavity was pulled, and the release resistance load when removing the polyurethane molded product from the mold was measured.

After measuring the demolding resistance load in this way, the number of times the polyurethane molded product was demolded (number of demolds) under a demolding load of 50 N or less with one application of release agent B-1 was measured. The results are shown in Table 2.

Example 6
99.7 g of water and polyoxyethylenestearylamine ("Nymeen S-220", NOF Corp.) were added to 0.1 g of the PO-L-PAE obtained in Example 2, and the mixture was stirred for about 30 minutes to prepare release agent B-2.

The same procedure as in Example 5 was carried out, except that release agent B-2 was used instead of release agent B-1, and the number of releases was measured. The results are shown in Table 2.

Example 7
To 0.1 g of the PO-L-PAE obtained in Example 2, 65 g of isopropanol and 34.7 g of water were added, and then 0.2 g of triethylamine was added with stirring, followed by stirring for about 30 minutes to prepare release agent B-3.

The same procedure as in Example 5 was carried out, except that release agent B-3 was used instead of release agent B-1, and the number of releases was measured. The results are shown in Table 2.

<Comparative Example 2>
To 0.1 g of R _f C ₆ -PAE obtained in Comparative Example 1, 65 g of isopropanol and 34.7 g of water were added, and then 0.2 g of triethylamine was added with stirring, followed by stirring for about 30 minutes to prepare release agent B-4.

The same procedure as in Example 5 was carried out, except that release agent B-4 was used instead of release agent B-1, and the number of releases was measured. The results are shown in Table 2.

<Comparative Example 3>
The above-described release test was carried out without using any release agent.

As shown in Table 2, in Examples 5 to 7, the polyurethane molded product could be released from the SUS mold many times, and had excellent releasability. In particular, in Example 2, the number of releases was 30, and the releasability was remarkably excellent. On the other hand, in Comparative Example 2, the number of releases was only two, and the releasability was poor. Also, in Comparative Example 3, the polyurethane molded product adhered to the SUS mold and could not be released.

Claims (8)

A perfluoropolyether phosphate ester represented by general formula (1) or a perfluoropolyether phosphate salt represented by general formula (2):

(In the above general formulas (1) and (2), n is an integer of 1 to 20, and _M1 is an alkali metal, an ammonium base, or an organic amine base;
_M2 is a hydrogen atom, an alkali metal, an ammonium base, or an organic amine base. A surface treatment agent containing the perfluoropolyether phosphate ester or perfluoropolyether phosphate ester salt according to claim 1. A coating agent comprising the perfluoropolyether phosphate ester or perfluoropolyether phosphate ester salt according to claim 1. 　A release agent comprising the perfluoropolyether phosphate ester or perfluoropolyether phosphate ester salt according to claim 1. The release agent according to claim 4, further comprising water. The release agent according to claim 4, further comprising an organic amine represented by general formula (3).
R ₁ -N-(R ₂ ) ₂ (3)
(In the above general formula (3), R ₁ is an alkyl group having 1 to 22 carbon atoms,
_R2 is represented by -(C _a H _2a O) _{b -R3} ;
a is an integer from 1 to 22;
b is an integer from 1 to 100;
_R3 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. a) Perfluoropolyether alcohol represented by general formula (4)

(wherein n is an integer of 1 to 20) in the presence of phosphorus oxychloride;
b) The compound represented by formula (5) obtained in step a)

(wherein n is an integer of 1 to 20)
c) optionally neutralizing the perfluoropolyether phosphate ester obtained in step b);
A method for producing a perfluoropolyether phosphate ester or a salt thereof, comprising:
The above-mentioned production method is characterized in that an equivalent ratio of the phosphorus oxychloride to the perfluoropolyether alcohol is 10 or more and 20 or less in terms of a molar ratio. The method of claim 7, in which calcium chloride is not used in step a).