JP7653341B2 - Perfluoropolyether phosphate ester and surface treatment composition containing same - Google Patents

Description

The present invention relates to a novel perfluoropolyether phosphate ester and a surface treatment composition containing the same.

Fluorine-containing phosphate esters are widely used as release agents, liquid repellents, etc. For example, Patent Document 1 discloses a compound having one phosphate group and one to three perfluoroalkyl or perfluoroalkenyl groups per molecule as a fluorine-containing phosphate ester. Patent Document 2 describes a treatment method for treating metals, marble, etc. with a perfluoropolyether phosphate ester compound to give them a liquid-repellent surface. However, conventional fluorine-containing phosphate esters do not provide sufficient performance for multiple releases with a single application (continuous release), and further improvements in release properties are required.

Japanese Patent Application Publication No. 05-194560 Patent No. 3574222

The present invention aims to provide a novel perfluoropolyether phosphate ester that has excellent surface functionality, such as releasability, resin adhesion prevention, and liquid repellency, as well as excellent continuous releasability, and a surface treatment composition that contains the perfluoropolyether phosphate ester.

In order to solve the above problems, the inventors conducted extensive research and discovered that the use of linear perfluoropolyether phosphate esters makes it possible to obtain a surface treatment composition that exhibits good surface functionality, continuous releasability, etc.

The present invention was completed based on these findings and includes the following broad aspects:

[Item 1]
A linear perfluoropolyether phosphate ester compound represented by formula (I).
[In the formula, ^R1 is a hydrocarbon group having 1 to 4 carbon atoms. m is 10 to 37. n is 10 to 37.]

[Item 2]
Item 2. A surface treatment composition comprising the linear perfluoropolyether phosphate compound according to item 1.

[Item 3]
Item 3. The surface treatment composition according to item 2, wherein the linear perfluoropolyether phosphate ester compound has a weight average molecular weight in the range of 2,000 to 7,000.

[Item 4]
Item 4. The surface treatment composition according to item 2 or 3, further comprising a branched perfluoropolyether phosphate compound represented by formula (II):
[In the formula, Rf is a perfluoroalkyl group having 1 to 4 carbon atoms. X is a fluoro group or a trifluoromethyl group. Y is a divalent group having 1 to 10 carbon atoms. p is 10 to 25.]

[Item 5]
Item 5. The surface treatment composition according to item 4, comprising the linear perfluoropolyether phosphate ester compound and the branched perfluoropolyether phosphate ester compound in a mass ratio of 5:5 to 10:0.

[Item 6]
Item 6. The surface treatment composition according to item 4 or 5, wherein the total concentration of the linear perfluoropolyether phosphate ester compound and the branched perfluoropolyether phosphate ester compound is in the range of 0.1 to 10 mass% based on the total amount of the composition.

[Item 7]
Item 7. A release agent comprising the surface treatment composition according to any one of items 2 to 6.

[Item 8]
Item 7. A resin adhesion inhibitor comprising the surface treatment composition according to any one of items 2 to 6.

[Item 9]
Item 7. A liquid repellent comprising the surface treatment composition according to any one of items 2 to 6.

The surface treatment composition using the novel perfluoropolyether phosphate ester of the present invention has excellent surface functionality such as releasability, resin adhesion prevention, and liquid repellency. In particular, when used as a release agent, it has excellent continuous release properties and is useful.

<Straight-chain perfluoropolyether phosphate ester compound>
The linear perfluoropolyether phosphate compound according to the present invention is a compound represented by general formula (I).

[In the formula, ^R1 is a hydrocarbon group having 1 to 4 carbon atoms. m is 10 to 37. n is 10 to 37.]

^R1 is a hydrocarbon group having 1 to 4 carbon atoms. Examples of the hydrocarbon group having 1 to 4 carbon atoms include an alkyl group and an alkenyl group having 1 to 4 carbon atoms. ^R1 is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group.

m is 10 to 37, preferably 15 to 35, more preferably 20 to 35, and most preferably 25 to 35.

n is 10 to 37, preferably 15 to 35, more preferably 20 to 35, and most preferably 25 to 35.

The linear perfluoropolyether phosphate ester compound represented by general formula (I) has a weight average molecular weight in the range of 2,000 to 7,000, preferably in the range of 3,000 to 6,000, more preferably in the range of 4,000 to 6,000, and most preferably in the range of 5,000 to 6,000. The weight average molecular weight can be measured by a conventional method such as gel filtration chromatography.

In addition, the linear perfluoropolyether phosphate compound represented by the general formula (I) can form metal salts, amine salts, ammonium salts, etc. by reacting with a basic metal compound, an amine compound, ammonia, etc., and these salts also have the same utility as the linear perfluoropolyether phosphate compound represented by the general formula (I). Examples of the metal salts include alkali metal salts, alkaline earth metal salts, transition metal salts, etc. Specific examples of metal atoms that form metal salts include Li, Na, K, Ca, Mg, Cu, Co, Ni, Zn, Mn, Fe, Pb, Hg, Zr, etc. Examples of amine compounds or ammonia that form amine salts or ammonium salts include ammonia, trimethylamine, triethylamine, benzylamine, methylbenzylamine, dimethylbenzylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, pyridine, etc.

Specific examples of linear perfluoropolyether phosphate ester compounds represented by general formula (I) include, but are not limited to, the following:

[In the formula, m is 10 to 37. n is 10 to 37.]

[In the formula, m is 10 to 37. n is 10 to 37.]

[In the formula, m is 10 to 37. n is 10 to 37.]

[In the formula, m is 10 to 37. n is 10 to 37.]

<Method of producing linear perfluoropolyether phosphate compound>
The linear perfluoropolyether phosphate ester compound represented by the general formula (I) can be obtained, for example, by a method including the following steps, but is not limited thereto:
(1) a step of substituting a hydrogen atom of one of the terminal hydroxyl groups of a linear perfluoropolyether diol represented by the following general formula (III) with a hydrocarbon group having 1 to 4 carbon atoms;

[In the formula, m is 10 to 37. n is 10 to 37.]
(2) A step of converting the other terminal hydroxyl group of the linear perfluoropolyether diol represented by the general formula (III) into a phosphoryl ester.

(1) A step of substituting a hydrogen atom of one of the terminal hydroxyl groups of a linear perfluoropolyether diol represented by the following general formula (III) with a hydrocarbon group having 1 to 4 carbon atoms. In this step, the hydrocarbon group having 1 to 4 carbon atoms to be substituted for the hydrogen atom of the hydroxyl group is a group corresponding to R ¹ in the above general formula (I), and those listed in the above general formula (I) are used.

The linear perfluoropolyether diol represented by general formula (III) has a weight average molecular weight in the range of 2,000 to 7,000, preferably in the range of 3,000 to 6,000, more preferably in the range of 4,000 to 6,000, and most preferably in the range of 5,000 to 6,000. The weight average molecular weight can be measured by a conventional method such as gel filtration chromatography.

The linear perfluoropolyether diol represented by the general formula (III) can be obtained as a commercial product or can be produced by a known method. Commercially available products include, for example, Fluorolink D-6000 (manufactured by Solvay) and Fluorolink D-4000 (manufactured by Solvay). The linear perfluoropolyether diol represented by the general formula (III) can also be synthesized according to the method disclosed in JP-A-2006-22334, etc.

The hydrogen atom of one of the terminal hydroxyl groups of the linear perfluoropolyether diol represented by the general formula (III) can be replaced with a hydrocarbon group having 1 to 4 carbon atoms by a known method for replacing a hydroxyl group. For example, when replacing with a methyl group, it can be obtained by using a methylating agent such as iodomethane and a base (alkali metal hydroxide, alkali metal tert-butoxide, etc.) on the linear perfluoropolyether diol.

(2) Step of phosphorylating the other terminal hydroxyl group of the linear perfluoropolyether diol represented by the general formula (III) The other terminal hydroxyl group of the product (monol) obtained in step (I) in which one terminal hydroxyl group of the linear perfluoropolyether diol is substituted with a hydrocarbon group having 1 to 4 carbon atoms can be phosphorylated by a known phosphorylation method. For example, it can be obtained by using diphosphorus pentoxide (P ₂ O ₅ ), phosphoryl chloride (POCl ₃ ), etc. When phosphorylation is performed using diphosphorus pentoxide (P ₂ O ₅ ), the reaction can be carried out by using 1.0 to 10 equivalents of diphosphorus pentoxide (P ₂ O ₅ ) relative to the monool and stirring at 60 to 80°C for 3 to 10 hours.

<Surface treatment composition>
In another embodiment, a surface treatment composition containing the linear perfluoropolyether phosphate compound of the present invention is provided. The surface treatment composition of the present invention contains the linear perfluoropolyether phosphate compound as an essential component, and is usually used in a state of being dissolved in a solvent.

In the surface treatment composition, the amount of the linear perfluoropolyether phosphate ester compound is usually 0.1 to 10% by mass, preferably 0.1 to 5% by mass, more preferably 0.1 to 2% by mass, and most preferably 0.1 to 1% by mass, based on the total amount of the surface treatment composition.

The solvent is not particularly limited as long as it is capable of dissolving the linear perfluoropolyether phosphate ester compound, and examples thereof include fluorine-based solvents. Preferred fluorine-based solvents include hydrofluoroethers, perfluorocarbons, and hydrofluorocarbons. From the viewpoint of the usability of the surface treatment composition, the boiling point of the solvent is preferably about 50 to 140°C, and more preferably about 70 to 140°C. Examples of such preferred solvents include commercially available products such as Galden SV-55, Galden SV-70, Galden SV-80, Galden SV-110, and Galden SV-135 (all manufactured by Solvay), Novec-7100, Novec-7200, and Novec-7300 (all manufactured by 3M), Fluorinert FC-40, Fluorinert FC-72, Fluorinert FC-770, and Fluorinert FC-3283 (all manufactured by 3M). The solvent may be used alone or in a mixture of two or more types.

In addition, the surface treatment composition of the present invention may further contain a branched perfluoropolyether phosphate ester compound represented by general formula (II).

[In the formula, Rf is a perfluoroalkyl group having 1 to 4 carbon atoms. X is a fluoro group or a trifluoromethyl group. Y is a divalent group having 1 to 10 carbon atoms. p is 10 to 25.]
In formula (II), Rf is a perfluoroalkyl group having 1 to 4 carbon atoms, such as a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, or a perfluorobutyl group.

X is a fluoro group or a trifluoromethyl group, preferably a trifluoromethyl group.

The divalent group having 1 to 10 carbon atoms represented by Y may contain a heteroatom and may be an aromatic group, a heteroaromatic group, a heterocyclic group, an aliphatic group, or an alicyclic group. Specific examples include the following groups.

-( _CH2 ) _N1 - (N1=1~10)
-A-(CH ₂ ) _N2 - (N2=1~5)
-B-(CH ₂ ) _N3 - (N3=1 to 5)
-CH ₂ CH ₂ (OCH ₂ CH ₂ ) _N4 - (N4=1 to 4)
-BCO(OCH ₂ CH ₂ ) _N5 - (N5=1 to 4)
(In the formula, A represents -O-CO-, -CO-O-, -CONH- or -NHCO-. B represents phenylene which may have 1 to 3 substituents selected from the group consisting of alkyl groups having 1 to 3 carbon atoms (methyl, ethyl, propyl), alkoxy groups having 1 to 4 carbon atoms (methoxy, ethoxy, propoxy, butoxy, etc.), and halogen atoms (F, Cl, Br, I).)
Preferred divalent groups having 1 to 10 carbon atoms represented by Y include divalent groups having the following structures:

-(CH ₂ ) _N1 - (N1=1 to 10)
-CONH-(CH ₂ ) _N2 - (N2=1 to 5)
-CO-O-(CH ₂ ) _N2 - (N2=1 to 5)
p is 10 to 25, preferably 12 to 20.

The branched perfluoropolyether phosphate ester compound represented by general formula (II) has a weight average molecular weight in the range of 2,000 to 4,000, preferably in the range of 2,500 to 3,500. The weight average molecular weight can be measured by a conventional method such as gel filtration chromatography.

Specific examples of linear perfluoropolyether phosphate ester compounds represented by general formula (II) include, but are not limited to, the following:

[In the formula, p is 10 to 25.]

[In the formula, p is 10 to 25.]

[In the formula, p is 10 to 25.]

The branched perfluoropolyether phosphate ester compound represented by the general formula (II) can be produced by a known method. It can also be obtained, for example, by phosphate esterification of the hydroxyl group of the perfluoropolyether monool represented by the general formula (IV).

[In the formula, Rf is a perfluoroalkyl group having 1 to 4 carbon atoms. X is a fluoro group or a trifluoromethyl group. Y is a divalent group having 1 to 10 carbon atoms. p is 10 to 25.]
In formula (IV), Rf, X and Y are the same as those in formula (II) above.

The perfluoropolyether monool represented by general formula (IV) has a weight average molecular weight in the range of 2,000 to 4,000, preferably in the range of 2,500 to 3,500. The weight average molecular weight can be measured by a conventional method such as gel filtration chromatography.

The perfluoropolyether monool represented by the general formula (IV) can be obtained commercially or can be produced by known methods. The perfluoropolyether monool represented by the general formula (III) can be synthesized according to the method disclosed in U.S. Patent Publication No. 3,293,306, etc.

The hydroxyl group of the perfluoropolyether monool represented by the general formula (III) can be converted into a phosphoric acid ester by a known method, for example, by using diphosphorus _pentoxide ( _P2O5 ).

When the surface treatment composition of the present invention further contains a branched perfluoropolyether phosphate ester compound, the linear perfluoropolyether phosphate ester compound and the branched perfluoropolyether phosphate ester compound are contained in a mass ratio of 3:7 to 10:0, preferably 5:5 to 10:0, and particularly preferably 5:5 to 8:2.

When the surface treatment composition of the present invention further contains a branched perfluoropolyether phosphate ester compound, the total amount of the linear perfluoropolyether phosphate ester compound and the branched perfluoropolyether phosphate ester compound is usually 0.1 to 10 mass %, preferably 0.1 to 5 mass %, more preferably 0.1 to 2 mass %, and most preferably 0.1 to 1 mass %, based on the total amount of the surface treatment composition.

Since branched perfluoropolyether phosphate ester compounds have superior liquid repellency compared to linear perfluoropolyether phosphate ester compounds, it is preferable to prepare a surface treatment composition by combining a linear perfluoropolyether phosphate ester compound and a branched perfluoropolyether phosphate ester compound.

The surface treatment composition of the present invention may be appropriately blended with rust inhibitors, catalysts, antibacterial agents, flame retardants, surfactants, defoamers, thickeners, viscosity regulators, leveling agents, UV absorbers, preservatives, antifreeze agents, wetting agents, pH adjusters, stabilizers, antifungal agents, light resistance stabilizers, weather resistance stabilizers, neutralizing agents, matting agents, drying accelerators, foaming agents, non-adhesive agents, deterioration inhibitors, etc., within the range that does not impair the object of the present invention.

The surface treatment composition of the present invention can be used as a release agent, a resin adhesion inhibitor, a liquid repellent, an agent to prevent flux creeping up, an antifouling agent, an anti-moisturizing agent, and an oil barrier agent.

The molding material to be released using the surface treatment composition of the present invention, or the resin material to be used for preventing resin adhesion, is not particularly limited, but examples thereof include rubbers such as urethane rubber, H-NBR, NBR, silicone rubber, EPDM, CR, NR, fluororubber, SBR, BR, IIR and IR, urethane foam, epoxy resin, polyimide resin, polyamide resin, melamine resin, urea resin, polyurethane, silicone resin, alkyd resin, phenolic resin, unsaturated polyester resin, vinyl ester resin and thermosetting resins such as FRP (glass fiber reinforced plastic (GFRP), carbon fiber reinforced plastic (CFRP), aramid fiber reinforced plastic (AFRP)), PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride), PS (polystyrene), PA (polyamide), polyester, polycarbonate, ABS resin, poly(meth)acrylic acid, polyacetal, polyvinylidene fluoride, polyphenylene sulfide, polyetherimide, polyether ether ketone, Examples include thermoplastic resins such as FRTP (glass fiber reinforced thermoplastic resin (GFRTP), carbon fiber reinforced thermoplastic resin (CFRTP), and aramid fiber reinforced thermoplastic resin (AFRTP)). In particular, it is useful as a mold release agent for resins such as urethane foam, polyurethane, and epoxy resin, and as a resin adhesion inhibitor for resins such as polyurethane, epoxy resin, and polyester.

The materials to which the surface treatment composition of the present invention is applied are not particularly limited, but examples include metals such as aluminum, SUS, and iron, resins such as PP, PE, and epoxy, rubber, FRP (fiber reinforced plastic), gypsum substrates, wooden substrates, composite materials, and the like.

When the surface treatment composition of the present invention is used as a mold release agent, for example, it can be used by applying it to the surface of the mold and drying it. The application method is not particularly limited, and examples thereof include spray application, brush application, roll coater application, and dipping application. Drying methods include air drying or a method in which the solvent is evaporated by heating to form a film. The amount of non-volatile components in the surface treatment composition to be applied to the mold is generally 0.01 to 10 g/ ^m2 , preferably 0.1 to 2 g/ ^m2 , which provides sufficient mold releasability.

The present invention will be further explained below with reference to examples, but the present invention is not limited thereto.

(Materials used)
Fluorolink D-6000: Linear perfluoropolyether diol (manufactured by Solvay)
_HOCH2CF2O- ( _{CF2CF2O ) m-} ( _{CF2O ) n} - _CF2CH2OH (average weight molecular weight: 6000, _m and n are approximately 32.)
Raw material 1: Branched perfluoropolyether monool
_CF3CF2CF2O- [CF(CF3) _{CF2O ] n-} CF( _CF3 ) _{CH2OH (} average molecular weight: 3000, _n is about 16.)
HFE-7200: Hydrofluoroether solvent (manufactured by 3M)
HFE-7300: Hydrofluoroether solvent (manufactured by 3M)
Galden SV-135: Perfluoropolyether solvent (manufactured by Solvay, boiling point 135°C)

(Synthesis Example 1) Methyl etherification of linear perfluoropolyether diol Fluorolink D-6000 (methylation of hydrogen atoms of terminal hydroxyl groups)
In a 30 ml eggplant flask with a stirrer, ^t BuOK (1.3 mmol, 0.146 g) and DMF (4.00 g) were weighed. Next, Fluorolink D-6000 (1.0 mmol, 6.00 g) and HFE-7200 (6.00 g) were weighed in the eggplant flask. The reaction solution was stirred at room temperature. In a dropping funnel, CH ₃ I (1.1 mmol, 0.156 g) and DMF (2.00 g) were weighed. The CH ₃ I solution was dripped from the dropping funnel into the reaction solution in the eggplant flask. After dripping, the reaction solution was stirred at 30°C for 4 hours. 5 g of 1N-HCl aqueous solution was added to the reaction solution to stop the reaction. Since the lower layer is the target product, the solvent in the upper layer was removed. The washing process using pure water was repeated three times. The washing process using IPA was repeated three times. The product was placed in a recovery flask and dried under reduced pressure to remove the solvent, synthesizing 5.73 g (yield: 95%) of methyl ether 1. ^{The 1} H-NMR and ¹⁹ F-NMR spectra of the obtained methyl ether 1 are as follows.
Methyl ether 1
CH ₃ OCH ₂ CF ₂ O-(CF ₂ CF ₂ O) _m -(CF ₂ O) _n -CF ₂ CH ₂ OH (average weight molecular weight 6000)
¹ H-NMR (CDCl ₃ ):δ3.47 (s, 3H, C H ₃ OCH ₂ CF ₂ ORf),3.67 (dd, J=9.19,16.39,2H, CH ₃ OC H ₂ CF ₂ ORf), 3.84 (dd, J=9.19,16.39,2H, RfOCF ₂ CH ₂ OH );
¹⁹ F-NMR (CDCl ₃ , C ₆ F ₆ ; δ-163): δ -88.29 to -86.63 (m, 4nF, -(C F ₂ C F ₂ O) _n -), -81.47 (m, 2F, CH ₃ OCH ₂ C F ₂ -ORf), -79.49 (m, 2F, RfO-C F ₂ CH ₂ OH), -53.08 to -49.74 (m, 2nF, -(C F ₂ O) _n -)

(Synthesis Example 2) Synthesis of linear perfluoropolyether phosphate ester 2 by phosphoric esterification of methyl ether 1 Methyl ether 1 (0.917mmol, 5.50g), _P2O5 (7.33mmol, 1.04g), and HFE- ₇₃₀₀ (22.0g) were weighed into a 30ml eggplant flask equipped with a stirrer. The reaction solution was stirred at 70°C for 5 hours. 10g of pure water was added to the reaction solution to stop the reaction. The lower layer was the target product, so the solvent in the upper layer was removed. The washing process using pure water was repeated three times. The washing process using IPA was repeated three times. The product was placed in an eggplant flask and dried under reduced pressure to remove the solvent, synthesizing linear perfluoropolyether phosphate ester 2 with a yield of 96% and 5.05g. ^{The 1H} -NMR and ^19F -NMR of the obtained linear perfluoropolyether phosphate ester 2 are as follows.
Linear perfluoropolyether phosphate ester 2
CH ₃ OCH ₂ CF ₂ O-(CF ₂ CF ₂ O) _m -(CF ₂ O)n-CF ₂ CH ₂ OPO(OH) ₂ (Average weight molecular weight 6000)
¹ H-NMR (CDCl ₃ ):δ3.46 (s, 3H, C H ₃ OCH ₂ CF ₂ ORf),3.67 (dd, J=9.19,16.39,2H, CH ₃ OC H ₂ CF ₂ ORf), 4.31 (m,2H, RfOCF ₂ C H ₂ OP(O)(OH) ₂ );
¹⁹ F-NMR (CDCl ₃ , C ₆ F ₆ ; δ-163): δ -88.29 to -86.63 (m, 4nF, -(C F ₂ C F ₂ O) _n -), -81.47 (m, 2F, CH ₃ OCH ₂ C F ₂ -ORf), -78.51 (m, 2F, RfO-C F ₂ CH ₂ OP(O(OH) ₂ ), -53.08 to -49.74 (m, 2nF, -(C F ₂ O) _n -)

(Synthesis Example 3) Synthesis of branched perfluoropolyether phosphate ester 3 by phosphoric esterification of branched perfluoropolyether monool (raw material 1) Branched perfluoropolyether monool (raw material 1) (1.0 mmol, 3.00 g), P ₂ O ₅ (10.0 mmol, 1.42 g), and HFE-7300 (10.0 g) were weighed into a 30 ml eggplant flask equipped with a stirrer. The reaction solution was stirred at 70°C for 5 hours. 10 g of pure water was added to the reaction solution to stop the reaction. The lower layer was the target product, so the solvent in the upper layer was removed. The washing process using pure water was repeated three times. The washing process using IPA was repeated three times. The product was placed in an eggplant flask, and the solvent was removed by drying under reduced pressure, and branched perfluoropolyether phosphate ester 3 was synthesized in a yield of 95%, 2.85 g. ^{The 1} H-NMR and ¹⁹ F-NMR spectra of the obtained branched perfluoropolyether phosphate ester 3 are as follows.
Branched perfluoropolyether phosphate ester 3
CF ₃ CF ₂ CF ₂ O-[CF(CF ₃ )CF ₂ O] _n -CF(CF ₃ )CH ₂ OPO(OH) ₂ (average weight molecular weight 3000)
¹ H-NMR (CDCl ₃ ): δ4.57 (m,2H, RfOCF(CF ₃ )C H ₂ OP(O)(OH) ₂ );
¹⁹ F-NMR (CDCl ₃ , C ₆ F ₆ ; δ-163): δ-145.78 (m, 1nF, -(C F (CF ₃ )CF ₂ O) _n -), -137.27 (m, 1F, RfOC F (CF ₃ )CH ₂ OP(O)(OH) ₂ ), -131.42 (s, 2F, CF ₃ C F ₂ CF ₂ ORf), -84.57 (m, 3F, C F ₃ CF ₂ CF ₂ ORf), -83.55 to -80.23 (m, 2F, CF ₃ CF ₂ C F ₂ ORf), -83.55 to -80.23 (m, 3nF, -(CF(C F ₃ )CF ₂ O) _n -), -83.55 to -80.23 (m, 2nF, -(CF(CF ₃ )C F ₂ O) _n -), -83.55 to -80.23 (m, 3F, RfOCF(C F ₃ )CH ₂ OP(O)(OH) ₂ )

Example 1
A test solution 1 was prepared by weighing out 0.50 g of the linear perfluoropolyether phosphate ester 2 produced in Synthesis Example 2 and 99.5 g of Galden SV-135 as a dilution solvent.

Example 2
A test solution 2 was prepared by weighing 0.25 g of the linear perfluoropolyether phosphate ester 2 produced in Synthesis Example 2, 0.25 g of the branched perfluoropolyether phosphate ester 3 produced in Synthesis Example 3, and 99.5 g of Galden SV-135 as a dilution solvent.

(Comparative Example 1)
A test solution 3 was prepared by weighing out 0.50 g of the branched perfluoropolyether phosphate ester 3 produced in Synthesis Example 3 and 99.5 g of Galden SV-135 as a dilution solvent.

(Tape peel test)
Test solution 1 prepared in Example 1 was applied to a cold-rolled steel plate SPCC-SB (size 110×30×8 mm) with a brush, and dried by heating at 110°C to prepare a test substrate. Nitto Denko 31b tape was applied to the test substrate, and a roller with a load of 2 kg was used to roll it back and forth twice. The end of the tape was folded, clamped with a clip, and pulled vertically to peel off the tape. The peeling force at this time was measured. The tape peeling test was repeated at the same location to confirm the durability. The same operation was also performed with test solutions 2 and 3. The evaluation results are shown in Table 1 and Figure 1.

From Example 1 and Comparative Example 1, it is clear that linear perfluoropolyether phosphate ester has better initial and continuous releasability than branched perfluoropolyether phosphate ester. In Example 2, the initial peel strength is lowered by using linear perfluoropolyether phosphate ester and branched perfluoropolyether phosphate ester in combination. Although the initial peel strength is high when branched perfluoropolyether phosphate ester is used alone, the combined use of linear perfluoropolyether phosphate ester and linear perfluoropolyether phosphate ester results in a lower peel strength. This is thought to be because linear perfluoropolyether phosphate ester mainly contributes to continuous releasability, but branched perfluoropolyether phosphate ester has better liquid repellency, and therefore the combined use of both esters results in a lower initial peel strength (Table 2).

In addition, in Examples 1 and 2, good peel strength was demonstrated even in peel tests conducted 15 times or more, and it is expected that when used in actual resin molding dies, it will be possible to perform continuous demolding work for a day by simply applying the agent at the start of work.

Evaluation criteria ◎: 1st time 0.5N or less and 8th time less than 1.0N 〇: 8th time less than 1.0N ×: 8th time 1.0N or more

Claims (9)

A linear perfluoropolyether phosphate ester compound represented by formula (I).
[In the formula, ^R1 is a hydrocarbon group having 1 to 4 carbon atoms. m is 10 to 37. n is 10 to 37.] A surface treatment composition comprising the linear perfluoropolyether phosphate ester compound according to claim 1. The surface treatment composition according to claim 2, wherein the weight average molecular weight of the linear perfluoropolyether phosphate ester compound is in the range of 2,000 to 7,000. The surface treatment composition according to claim 2 or 3, further comprising a branched perfluoropolyether phosphate compound represented by formula (II).
[In the formula, Rf is a perfluoroalkyl group having 1 to 4 carbon atoms. X is a fluoro group or a trifluoromethyl group. Y is a divalent group having 1 to 10 carbon atoms. p is 10 to 25.] The surface treatment composition according to claim 4, which contains the linear perfluoropolyether phosphate ester compound and the branched perfluoropolyether phosphate ester compound in a mass ratio of 5:5 to 10:0. The surface treatment composition according to claim 4 or 5, wherein the total concentration of the linear perfluoropolyether phosphate ester compound and the branched perfluoropolyether phosphate ester compound is in the range of 0.1 to 10 mass% based on the total amount of the composition. A release agent comprising the surface treatment composition according to any one of claims 2 to 6. A resin adhesion inhibitor comprising the surface treatment composition according to any one of claims 2 to 6. A liquid repellent comprising the surface treatment composition according to any one of claims 2 to 6.