Fluorine-containing polymer, fluorine-containing monomer, and article

Abstract

A fluorine-containing polymer according to the present disclosure includes a constituent unit represented by formula (1). In formula (1), R1 is a fluorine-containing alkyl group including a branch structure, and R2 is a hydrogen atom or a methyl group.

Description

Fluorine-containing polymers, fluorine-containing monomers, and articles

[0001] The present disclosure relates to fluorine-containing polymers, fluorine-containing monomers, and articles.

[0002] Fluorine-containing polymers are used in a variety of fields because of their excellent heat resistance, chemical resistance, oil resistance, weather resistance, electrical insulation, water and oil repellency, and the like.

[0003] For example, Non-Patent Document 1 describes poly(fluoroalkyl acrylate).

[0004] Takahara, Macromolecules, 2005, 38, 5699-5705

[0005] There is a demand for the development of novel fluorine-containing polymers.

[0006] An object of one embodiment of the present disclosure is to provide a novel fluoropolymer. Another object of the present disclosure is to provide a fluoromonomer useful for producing the fluoropolymer. Still another object of the present disclosure is to provide an article using the fluoropolymer.

[0007] The means for solving the above problems include the following aspects: <1> A fluorine-containing polymer containing a constitutional unit represented by the following formula (1): In formula (1), R １ is a fluorine-containing alkyl group having a branched structure, and R ２ is a hydrogen atom or a methyl group. <2> R １ <3> The fluorine-containing polymer according to <1>, wherein the fluorine-containing alkyl group has 2 to 10 carbon atoms. １ (CF ３ ) ３ C- or (CF ３ ) ２ <4> The fluoropolymer according to any one of <1> to <3>, wherein the proportion of the structural unit represented by formula (1) is 95 mass % or more. <5> A fluoromonomer represented by the following formula (2): １is a fluorine-containing alkyl group having a branched structure, and R ２ is a hydrogen atom or a methyl group. <6> An article having a film containing the fluorine-containing polymer according to any one of <1> to <5> on its surface.

[0008] According to one embodiment of the present disclosure, a novel fluoropolymer is provided. According to another embodiment of the present disclosure, a fluoromonomer useful for producing the fluoropolymer is provided. According to another embodiment of the present disclosure, an article using the fluoropolymer is provided.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail. However, the embodiments of the present disclosure are not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the embodiments of the present disclosure.

[0010] In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified.

[0011] [Fluoropolymer] The fluoropolymer of the present disclosure contains a constitutional unit represented by the following formula (1): １ is a fluorine-containing alkyl group having a branched structure, and R ２ is a hydrogen atom or a methyl group.

[0012]

[0013] The fluoropolymer of the present disclosure has a rigid benzene ring to which a fluoroalkyl group having a branched structure is bonded. This unconventional molecular design is expected to result in unconventional performance.

[0014] [R １ ] R relative to the benzene ring １ The bonding position of R is not particularly limited, and may be any of the ortho, meta, and para positions. １ The bonding position of is preferably the meta or para position, more preferably the para position.

[0015] That is, the fluoropolymer of the present disclosure preferably contains at least one selected from the group consisting of a constitutional unit represented by the following formula (1A) and a constitutional unit represented by the following formula (1B), and more preferably contains a constitutional unit represented by the following formula (1A):

[0016] R in formula (1A) and formula (1B) １ and R ２ is R in formula (1). １ and R ２ is the same as

[0017]

[0018] R １ is a fluorine-containing alkyl group having a branched structure. １ The fluorine-containing alkyl group represented by the formula (I) may be a partial fluoroalkyl group or a perfluoroalkyl group.

[0019] The term "partially fluoroalkyl group" refers to a group in which some of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms, and the term "perfluoroalkyl group" refers to a group in which all of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms.

[0020] Among these, from the viewpoint of excellent water repellency and oil repellency, R １ is preferably a perfluoroalkyl group containing a branched structure.

[0021] R １The fluorine-containing alkyl group represented by the formula (I) preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and even more preferably 3 or 4 carbon atoms.

[0022] R １ For example, (CF ３ ) ３ C-, (CF ３ ) ２ CF-, (CF ３ ) ２ CH-, (CF ３ ) ３ CCF ２ -, (CF ３ ) ３ CCHF-, (CF ３ ) ３ CCH ２ -, (CF ３ ) ２ CFCF ２ -, (CF ３ ) ２ CHCF ２ -, CF ３ -CF ２ -C(CF ３ ) ２ -, (CF ３ ) ２ -CF-CF ２ -CF ２ -, (CF ３ ) ２ -CH-CF ２ -CF ２ -, (CF ３ ) ３ -C-CF ２ -CF ２ -, CF ３ -CF ２ -C(CF ３ ) ２ -CF ２ - and CF ３ -CF ２ -CF ２ -C(CF ３ ) ２ - are listed.

[0023] Among these, from the viewpoint of excellent water repellency and oil repellency, R １ (CF ３ ) ３ C-, (CF ３ ) ２CF-, (CF ３ ) ３ CCF ２ -, (CF ３ ) ２ CFCF ２ -, CF ３ -CF ２ -C(CF ３ ) ２ -, (CF ３ ) ２ -CF-CF ２ -CF ２ -, (CF ３ ) ３ -C-CF ２ -CF ２ -, CF ３ -CF ２ -C(CF ３ ) ２ -CF ２ - or CF ３ -CF ２ -CF ２ -C(CF ３ ) ２ - is preferred, (CF ３ ) ３ C- or (CF ３ ) ２ CF- is more preferred.

[0024] [R ２ 〕 R ２ is a hydrogen atom or a methyl group, preferably a hydrogen atom.

[0025] Examples of the constitutional unit represented by formula (1) include the following constitutional units.

[0026]

[0027] The fluoropolymer of the present disclosure may contain other structural units in addition to the structural unit represented by formula (1).

[0028] The other structural unit is not particularly limited as long as it is a structural unit that can be bonded to the structural unit represented by formula (1). Examples of the other structural unit include structural units derived from (meth)acrylic acid, (meth)acrylic acid esters, styrene-based compounds, and vinyl compounds.

[0029] From the viewpoint of excellent water repellency and oil repellency, in the fluoropolymer of the present disclosure, the proportion of the constitutional unit represented by formula (1) is preferably 95% by mass or more, more preferably 98% by mass or more. The above proportion may be 100% by mass. The fluoropolymer of the present disclosure may be composed only of the constitutional unit represented by formula (1).

[0030] The number average molecular weight (Mn) of the fluoropolymer of the present disclosure is preferably from 5,000 to 100,000, more preferably from 10,000 to 80,000, from the viewpoint of both exhibiting the functions as a polymer and being easy to produce industrially.

[0031] The dispersity (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the fluoropolymer of the present disclosure is preferably 1 to 3, and more preferably 1 to 2.

[0032] In the present disclosure, the number average molecular weight and the weight average molecular weight are measured using gel permeation chromatography (GPC / SEC analysis system (manufactured by JASCO Corporation, pump: PU-4185, autosampler: AS-4150, column oven: CO-4060, RI detector: RI-4035, PDA detector: MD-4010), column (manufactured by Shodex, GPC HK-404L)) using a 6:4 mixed solvent of tetrahydrofuran and 1,3-bistrifluoromethylbenzene as the solvent, and are calculated as polymethyl methacrylate.

[0033] The fluoropolymer of the present disclosure contains a constituent unit represented by formula (1), and can be produced, for example, by carrying out a polymerization reaction using a fluoromonomer represented by the following formula (2).

[0034]

[0035] In formula (2), R １ is a fluorine-containing alkyl group having a branched structure, and R ２ is a hydrogen atom or a methyl group. １ and R ２ is R in formula (1). １ and R ２ is the same as

[0036] The polymerization reaction can be carried out by a conventional method. The polymerization initiator can be, for example, an azo polymerization initiator, and azoisobutyronitrile is preferably used. The polymerization solvent is not particularly limited as long as it can dissolve the monomers to be polymerized.

[0037] The reaction temperature of the polymerization reaction can be set appropriately. From the viewpoint of the reaction rate, the reaction temperature is preferably 30 to 150°C, more preferably 50 to 120°C. The reaction time of the polymerization reaction can be set appropriately. From the viewpoint of improving the yield and productivity, the reaction time is preferably 1 to 50 hours.

[0038] The reactor is not particularly limited. A complete mixing type stirred tank reactor or a piston flow type tubular reactor can be used as the reactor. Materials for the reactor, stirring blades, piping, etc. include stainless steels such as SUS304, SUS304L, SUS316, and SUS316L; Hastelloy alloys; and glass.

[0039] [Fluorine-containing monomer] The fluorine-containing monomer of the present disclosure is represented by the above formula (2): The fluorine-containing monomer of the present disclosure is useful for producing the fluorine-containing polymer of the present disclosure.

[0040] [Article] The article of the present disclosure preferably has a film containing the fluoropolymer of the present disclosure on its surface. By having a film containing the fluoropolymer of the present disclosure on its surface, the article of the present disclosure can obtain good water and oil repellency.

[0041] Next, embodiments of the present disclosure will be specifically described using examples, but the embodiments of the present disclosure are not limited to these examples.

[0042] [Identification of Compounds and Polymers] The NMR apparatus used for the analysis was a JNM-ECZ400S (400 MHz) manufactured by JEOL Ltd. １ In H NMR, tetramethylsilane was used as the reference value at 0 ppm.

[0043] The number average molecular weight (M ｎ ) and molecular weight distribution index (M ｗ / M ｎThe measurement was carried out using gel permeation chromatography (GPC / SEC analysis system (manufactured by JASCO Corporation, pump: PU-4185, autosampler: AS-4150, column oven: CO-4060, RI detector: RI-4035, PDA detector: MD-4010), column (manufactured by Shodex, GPC HK-404L)) using a 6:4 (volume ratio) mixed solvent of tetrahydrofuran and 1,3-bistrifluoromethylbenzene as the solvent, and the value was calculated as polymethyl methacrylate.

[0044] The recycle preparative HPLC used for separating the isomers was LaboACE, LC-5060 manufactured by Japan Analytical Industry Co., Ltd., and the column used was JAIGEL-SIL, SH-043-10.

[0045] [Example 1] <Synthesis of Compound 2>

[0046]

[0047] To a recovery flask equipped with a Dean-Stark apparatus, 11 g of the above compound 1 (4'-hydroxy-3'-iodoacetophenone, Sigma-Aldrich, 42 mmol), 24 mL of ethylene glycol (Tokyo Chemical Industry Co., Ltd., 430 mmol), 80 mg of p-toluenesulfonic acid monohydrate (Kanto Chemical Co., Ltd., 0.43 mmol), and 300 mL of toluene were added. The recovery flask was then heated to 135°C and reacted for 72 hours. The resulting product was purified by column chromatography (n-hexane / ethyl acetate = 2 / 1 (volume ratio)), yielding 7.5 g (25 mmol, 58% yield) of compound 2 as a white solid. The structure of compound 2 is as follows:

[0048]

[0049] Compound 2 １ H-NMR is as follows:

[0050] １ H-NMR (400MHz, CDCl ３ ​) δ (ppm): 7.77 (d, J = 2.1 Hz, 1H), 7.35 (dd, J = 8.4, 2.1 Hz, 1H), 6.95 ( d, J = 8.4Hz, 1H), 4.06-3.99 (m, 2H), 3.81-3.75 (m, 2H), 1.62 (s, 3H)

[0051] <Synthesis of Compound 3> 7.3 mg of the obtained compound 2 was dissolved in 80 mL of tetrahydrofuran in a recovery flask under a nitrogen atmosphere, and 7.5 mL of 1,1,1,3,3,3-hexamethyldisilazane (Tokyo Chemical Industry Co., Ltd., 36 mmol) was added, followed by stirring at 80°C for 2 hours. The solvent was distilled off under reduced pressure to obtain a crude product of compound 3. The structure of compound 3 is as follows:

[0052]

[0053] Compound 3 １ H-NMR is as follows:

[0054] １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 7.86 (d, J = 2.2Hz, 1H), 7.31 (dd, J = 8.3, 2.2Hz, 1H), 6.77 (d, J = 8.3Hz, 1H) , 4.02 (td, J=6.2, 4.2Hz, 2H), 3.79 (td, J=6.1, 4.2Hz, 2H), 1.62 (s, 3H), 0.33 (s, 9H)

[0055] <Synthesis of Compound 4> The obtained compound 3 was dissolved in 80 mL of tetrahydrofuran in a recovery flask under a nitrogen atmosphere, and 17 mL of n-butyllithium (Kanto Chemical Co., Inc., 26 mmol) was added dropwise in a dry ice acetone bath. After stirring for 1 hour, 30 mL of methanol was added. Ethyl acetate was added to the reaction solution containing the obtained crude product, and the mixture was washed with water. The aqueous layer was extracted twice with ethyl acetate, and the combined organic extracts were dried over sodium sulfate, and the solvent was evaporated under reduced pressure to obtain compound 4. The structure of compound 4 is as follows:

[0056]

[0057] Compound 4 １ H-NMR is as follows:​

[0058] １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 7.44 (d, J = 2.3Hz, 1H), 7.33 (dd, J = 8.3, 2.3Hz, 1H), 6.64 (d, J = 8.3Hz, 1H) , 4.03 (td, J=6.1, 4.2Hz, 2H), 3.80 (td, J=6.1, 4.2Hz, 2H), 1.65 (s, 3H), 0.31 (s, 9H)

[0059] <Synthesis of Compound 5> 6.0 g (24 mmol) of the obtained compound 4 and 4 mL of pyridine (Tokyo Chemical Industry Co., Ltd., 48 mmol) were dissolved in 48 mL of dichloromethane in a recovery flask under a nitrogen atmosphere, and 6 mL of trifluoromethanesulfonic anhydride (Tokyo Chemical Industry Co., Ltd., 36 mmol) was added dropwise in an ice bath. After stirring for 30 minutes, ethyl acetate was added to the resulting reaction solution containing the crude product, followed by washing with water. The aqueous layer was extracted twice with ethyl acetate, and the combined organic extracts were dried over sodium sulfate, and the solvent was evaporated under reduced pressure. 6.7 g (17 mmol, 71% yield) of compound 5 was obtained as a white solid. The structure of compound 5 is as follows:

[0060]

[0061] Compound 5 １ H-NMR and １９ The F-NMR is as follows: １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 7.62 (d, J = 2.4 Hz, 1H), 7.54 (dd, J = 8.7, 2.4 Hz, 1H), 7.29 (d, J = 8.6 Hz, 1H), 4.06 (td, J=6.3, 3.6Hz, 2H), 3.78 (td, J=6.3, 4.5Hz, 2H), 1.64 (s, 3H), 0.37 (s, 9H) １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -73.87 (s, 3F)

[0062] ​<Synthesis of Compound 6> Under a nitrogen atmosphere, 37 g of triphenylphosphine (Tokyo Chemical Industry Co., Ltd., 140 mmol) was dissolved in 80 mL of benzonitrile (Sigma-Aldrich) in a round-bottom Schlenk tube, which was then placed in a bath of mixed solvent (methanol / water = 3 / 7 (volume ratio)) containing dry ice. 23 g of carbon tetrabromide (Tokyo Chemical Industry Co., Ltd., 70 mmol) dissolved in 10 mL of benzonitrile was added dropwise to the Schlenk tube and stirred for 40 minutes. 82 mL of concentrated sulfuric acid was placed in a separate flask. The round-bottom Schlenk tube and the flask were connected with a PTFE tube while immersed in a liquid nitrogen bath. 20 mL of hexafluoroacetone trihydrate (Sigma-Aldrich, 140 mmol) was added dropwise to the flask over 1.5 hours. The round-bottom Schlenk tube was then sealed and stirred at room temperature (25°C) for 2 hours. The solid was removed by filtration through Celite, and the residue was distilled under reduced pressure to obtain 24 mmol (yield 35%) of colorless liquid Compound 6. The structure of Compound 6 is as follows:

[0063]

[0064] Compound 6 １９ The F-NMR is as follows:

[0065] １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -59.20 (s, 9F)

[0066] ​Synthesis of Compound 7: In an argon atmosphere, 560 mg (1.5 mmol) of compound 6 was added dropwise to a solution of 760 mg of cesium fluoride (Tokyo Chemical Industry Co., Ltd., 5.0 mmol) in 10 mL of acetonitrile in a Schlenk tube, followed by stirring for 30 minutes. Next, 380 mg (1.0 mmol) of compound 5 dissolved in 5 mL of acetonitrile was added dropwise, followed by stirring at room temperature (25°C) for 24 hours. Subsequently, 5 mL of methanol and 5 mL of saturated aqueous sodium bicarbonate solution were added, followed by stirring for 5 minutes. Ethyl acetate was added to the resulting reaction solution containing the crude product, followed by washing with water. The aqueous layer was extracted twice with ethyl acetate, and the combined organic extracts were dried over sodium sulfate, and the solvent was evaporated under reduced pressure. Compound 7 was obtained with an NMR yield of 75%. Compound 7 was a mixture of isomers, with the molar ratio of isomer 7a to isomer 7b being 44:56. The structure of isomer 7a is shown below.

[0067]

[0068] Isomer 7a １９ The F-NMR is as follows:

[0069] １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -62.46 (s, 9F)

[0070] The structure of isomer 7b is as follows:

[0071]

[0072] Isomer 7b １９ The F-NMR is as follows:

[0073] １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -62.43 (s, 9F)

[0074] ​​<Synthesis of Compound 8> Under a nitrogen atmosphere, compound 7 (0.75 mmol) and 9 mg of p-toluenesulfonic acid monohydrate (Kanto Chemical Co., Inc., 5 mmol%) were dissolved in 10 mL of a mixed solvent (acetone / water = 3 / 1 (volume ratio)) in a recovery flask. The mixture was stirred overnight in an oil bath at 75°C. Ethyl acetate was added to the reaction solution containing the obtained crude product, and the mixture was washed with water. The aqueous layer was extracted twice with ethyl acetate, and the combined organic extracts were dried over sodium sulfate, and the solvent was evaporated under reduced pressure. Compound 8 was obtained with an NMR yield of 95% or more. Compound 8 was a mixture of isomers, with the molar ratio of isomer 8a to isomer 8b being 45:55. The structure of isomer 8a is as follows:

[0075]

[0076] Isomer 8a １ H-NMR and １９ The F-NMR is as follows:

[0077] １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 8.04 (d, J=9.2Hz, 2H), 7.87 (d, J=8.5Hz, 2H), 2.65 (s, 3H). １９ F-NMR (376MHz, CDCl ３ ) δ (ppm) - 62.72 (s, 9F)

[0078] The structure of isomer 8b is as follows:

[0079]

[0080] Isomer 8b １ H-NMR and １９ The F-NMR is as follows:

[0081] １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 8.39 (s, 1H), 8.10 (d, J = 7.6Hz, 1H), 7.94 (d, J = 8.3Hz, 1H), 7.60 (d, 1H), 2.64 (s, 3H) １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -62.84 (s, 9F)​​

[0082] <Synthesis of Compound 9> In a recovery flask under a nitrogen atmosphere, compound 8 (0.94 mmol) and 38 mg of sodium borohydride (Tokyo Chemical Industry Co., Ltd., 1.0 mmol) were dissolved in tetrahydrofuran. The flask was placed in an ice bath, and 1 mL of methanol was added dropwise and stirred for two hours. Diethyl ether was added to the resulting reaction solution containing the crude product, which was then washed with water. The aqueous layer was extracted twice with diethyl ether, and the combined organic extracts were dried over sodium sulfate. The solvent was evaporated under reduced pressure. Compound 9 was obtained in an NMR yield of 86%. Compound 9 was a mixture of isomers, with the ratio of isomer 9a to isomer 9b being 44:56. The resulting structural isomers were purified by high-performance liquid chromatography (n-hexane / ethyl acetate = 6 / 4 (volume ratio)). The structure of isomer 9a is shown below.

[0083]

[0084] Isomer 9a １ H-NMR and １９ The F-NMR is as follows:

[0085] １ H-NMR (400 MHz, CDCl ３ ) δ (ppm): 7.72 (d, J = 8.3 Hz, 2H), 7.48 (d, J = 8.5 Hz, 2H), 4.96 (qd , J=6.2, 3.3Hz, 1H), 1.85 (d, J=3.7Hz, 1H), 1.52 (d, J=6.5Hz, 3H) １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -62.52 (s, 9F)

[0086] The structure of isomer 9b is as follows:

[0087]

[0088] Isomer 9b １ H-NMR and １９ The F-NMR is as follows:

[0089] １ H-NMR (400MHz, CDCl ３ ​​) δ (ppm): 7.74 (s, 1H), 7.64 (d, J = 8.2Hz, 1H), 7.54 (d, J = 7.7Hz, 1H), 7.46 ( t, J=7.9Hz, 1H), 4.95 (q, J=6.4Hz, 1H), 1.90 (s, 1H), 1.51 (d, J=6.5Hz, 3H) １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -62.38 (s, 9F)

[0090] <Separation of Isomer 9a and Isomer 9b> Isomer 9a and Isomer 9b were separated using recycle preparative HPLC.

[0091] <Synthesis of Compound 10a> Under a nitrogen atmosphere, 180 mg (0.52 mmol) of isomer 9a and 0.090 mL of triethylamine (Tokyo Chemical Industry Co., Ltd., 0.60 mmol) were dissolved in 2.5 mL of methylene chloride in a recovery flask. The flask was placed in an ice bath, and 0.050 mL of methanesulfonyl chloride (Tokyo Chemical Industry Co., Ltd., 0.60 mmol) was added dropwise, followed by stirring for 2 hours. Methylene chloride was added to the resulting reaction solution containing the crude product, and the mixture was washed with a 5% aqueous citric acid solution. The aqueous layer was extracted twice with methylene chloride, and the combined organic extracts were dried over sodium sulfate to obtain 198 mg (0.47 mmol, 92% yield) of compound 10a as a white solid. The structure of compound 10a is shown below. Ms means a methanesulfonyl group.

[0092]

[0093] Compound 10a １ H-NMR and １９ The F-NMR is as follows:

[0094] １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 7.78 (d, J = 8.4 Hz, 2H), 7.51 (d, J = 9.0 Hz, 2H), 5.79 (q, J = 6.6 Hz, 1H), 2.88 (s, 3H), 1.74 (d, J = 6.6Hz, 3H) １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -62.46 (s, 9F) ​

[0095] <Synthesis of Compound 11a> In a nitrogen atmosphere, 167 mg (0.40 mmol) of Compound 10a and 100 mg of potassium hydrogen sulfate (Kanto Chemical Co., Inc., 0.73 mmol) were dissolved in 3 mL of benzotrifluoride in a recovery flask. The mixture was stirred for 2 hours in an oil bath at 120°C. The resulting crude product was filtered through Celite and purified by flash silica gel column chromatography (n-pentane) to obtain 51 mg (0.16 mmol, 39% yield) of Compound 11a as a white solid.

[0096] The structure of compound 11a is as follows:

[0097]

[0098] Compound 11a １ H-NMR and １９ The F-NMR is as follows:

[0099] １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 7.69 (d, J = 8.3 Hz, 2H), 7.49 (d, J = 8.7 Hz, 2H), 6.73 (dd, J = 17.6 10.9Hz, 1H), 5.86 (dd, J=17.6, 0.7Hz, 1H), 5.40 (dd, J=10.9, 0.6Hz, 1H) １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -62.53 (s, 9F)

[0100] ​<Synthesis of Polymer a> Under a nitrogen atmosphere, 39 mg (0.12 mmol) of compound 11a and 0.12 mL of a 1,3-bistrifluoromethylbenzene solution (1 mmol%) of recrystallized azoisobutyronitrile (Kanto Chemical Co., Inc.) were added to an NMR tube, and freeze-degassing was performed three times. The mixture was stirred in an 80°C water bath for 24 hours. The solvent was evaporated under reduced pressure, and the mixture was redissolved in a small amount of 1,3-bistrifluoromethylbenzene solution. The resulting solution was reprecipitated using 100 mL of methanol, and the solid was recovered by centrifugation followed by filtration. The resulting solid was dried in vacuo to obtain 10 mg of polymer a (Mn = 19,100, Mw / Mn = 1.26) as a white solid. Polymer a was a homopolymer containing structural units derived from the monomer of compound 11a.

[0101] Example 2 Compound 9 was synthesized in the same manner as in Example 1, and isomers 9a and 9b were separated.

[0102] <Synthesis of Compound 10b> Compound 10b was obtained from 170 mg (0.50 mmol) of isomer 9b in a manner similar to that used for the synthesis of compound 10a. Methylene chloride was added to the reaction solution containing the obtained crude product, and the mixture was washed with a 5% aqueous citric acid solution. The aqueous layer was extracted twice with methylene chloride, and the combined organic extracts were dried over sodium sulfate to obtain 190 mg (0.45 mmol, 90% yield) of compound 10b as a white solid.

[0103] The structure of compound 10b is as follows:

[0104]

[0105] Compound 10b １ H-NMR and １９ The F-NMR is as follows:

[0106] １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 7.76 (m, 1H), 7.58 (d, J = 7.7Hz, 1H), 7.54 (t, J = 7.7Hz, 2H), 5.78 (q, J = 6.6Hz, 1H), 2.77 (s, 3H), 1.74 (d, J = 6.6Hz, 3H) １９ F-NMR (376MHz, CDCl​３ ) δ (ppm): -62.38 (s, 9F)

[0107] <Synthesis of Compound 11b> Compound 11b was obtained from 155 mg (0.37 mmol) of compound 10b in a manner similar to that used for the synthesis of compound 11a. The resulting crude product was filtered through Celite and purified by flash silica gel column chromatography (n-pentane) to obtain 81 mg (0.25 mmol, 68% yield) of compound 11b as a colorless liquid.

[0108] The structure of compound 11b is as follows:

[0109]

[0110] Compound 11b １ H-NMR and １９ The F-NMR is as follows:

[0111] １ H-NMR (400MHz, CDCl ３ ) δ (ppm): 7.72 (s, 1H), 7.62 (d, J = 8.0Hz, 1H), 7.57 (dJ = 7.8Hz, 1H), 7.44 (t, J = 8.0Hz , 1H), 6.74 (dd, J = 17.6, 10.9Hz, 1H), 5.79 (d, J = 17.6Hz, 1H), 5.36 (d, J = 10.9Hz, 1H) １９ F-NMR (376MHz, CDCl ３ ) δ (ppm): -62.37 (s, 9F)

[0112] <Synthesis of Polymer b> 53 mg (0.16 mmol) of compound 11b was polymerized in the same manner as in the synthesis of polymer a. The solvent was evaporated under reduced pressure, and the compound was redissolved in a small amount of 1,3-bistrifluoromethylbenzene solution. The resulting solution was reprecipitated using 100 mL of methanol, and the solid was collected by centrifugation followed by filtration. The resulting solid was dried in vacuo to obtain 35 mg (Mn = 34,000, Mw / Mn = 1.3) of polymer b as a white solid. Polymer b was a homopolymer containing structural units derived from the monomer of compound 11b.

[0113] [Evaluation] The obtained polymer was evaluated as follows. ​

[0114] <Glass Transition Temperature> The glass transition temperature (Tg) was measured using a differential scanning calorimeter DSC-25 (manufactured by TA Instruments) by raising the temperature at a rate of 10° C. per minute.

[0115] <Contact Angle> Polymers a and b were dissolved in 1,3-bistrifluoromethylbenzene at 130°C, applied to a piranha-treated silicon substrate, and dried at room temperature (25°C). The resulting thin film was heat-treated at 155°C for 6 hours under vacuum. The contact angle was measured on the resulting thin film when 1.5 μL of distilled water and 1 μL of diiodomethane were dropped onto the thin film using a contact angle meter (DMo-502, manufactured by Kyowa Interface Science Co., Ltd.).

[0116]

[0117] The fluoropolymer of the present disclosure is a novel fluoropolymer. Table 1 shows that the surface-treated layer obtained by surface treatment using the fluoropolymer of the present disclosure has good water and oil repellency.

[0118] [Example 3] <Synthesis of Polymer c> Under a nitrogen atmosphere, 21 mg (0.064 mmol) of compound 11a, 132 mg (1.26 mmol) of styrene, and 2.1 mg (1 mmol%) of recrystallized azoisobutyronitrile (Kanto Chemical Co., Ltd.) were added to a flask, and freeze-degassing was performed three times. The mixture was stirred in an 80°C water bath for 24 hours. The solvent was evaporated under reduced pressure, and the mixture was redissolved in a small amount of THF. The resulting solution was reprecipitated using methanol, and the solid was recovered by centrifugation followed by filtration. The resulting solid was then dried under vacuum to obtain a white solid polymer c (Mn = 28,000, Mw / Mn = 3.39). Polymer c was a copolymer containing structural units derived from the monomer of compound 11a and structural units derived from styrene in a molar ratio of 6:94.

[0119] [Example 4] <Synthesis of Polymer d> Under a nitrogen atmosphere, 39 mg (0.12 mmol) of compound 11a, 130 mg (1.24 mmol) of styrene, and 2.1 mg (1 mmol%) of recrystallized azoisobutyronitrile (Kanto Chemical Co., Ltd.) were added to a flask, and freeze-degassing was performed three times. The mixture was stirred in an 80°C water bath for 24 hours. The solvent was evaporated under reduced pressure, and the mixture was redissolved in a small amount of THF. The resulting solution was reprecipitated using methanol, and the solid was recovered by centrifugation followed by filtration. The resulting solid was then dried under vacuum to obtain a white solid polymer d (Mn = 38,000, Mw / Mn = 2.43). Polymer d was a copolymer containing structural units derived from the monomer of compound 11a and structural units derived from styrene in a molar ratio of 16:84. [Example 5] <Synthesis of Polymer e> Under a nitrogen atmosphere, 79 mg (0.23 mmol) of compound 11a, 58 mg (0.56 mmol) of styrene, and 1.4 mg (1 mmol%) of recrystallized azoisobutyronitrile (Kanto Chemical Co., Inc.) were added to a flask, and freeze-degassing was performed three times. The mixture was stirred in an 80°C water bath for 24 hours. The solvent was evaporated under reduced pressure, and the mixture was redissolved in a small amount of THF. The resulting solution was reprecipitated in methanol, and the solid was recovered by centrifugation and filtration. The resulting solid was redissolved in THF, reprecipitated with methanol, and vacuum-dried to obtain a white solid polymer e (Mn = 58,000, Mw / Mn = 1.97). Polymer e was a copolymer containing structural units derived from the monomer of compound 11a and structural units derived from styrene in a molar ratio of 34:66.

[0120] The obtained polymer was evaluated in the same manner as for polymers a and b.

[0121]

[0122] The fluoropolymer of the present disclosure is a novel fluoropolymer. Table 2 shows that the surface-treated layer obtained by surface treatment using the fluoropolymer of the present disclosure has good water and oil repellency.

[0123] The disclosures of Japanese Patent Application No. 2024-146923 filed on August 28, 2024 and Japanese Patent Application No. 2025-066668 filed on April 15, 2025 are incorporated herein by reference in their entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. A fluorine-containing polymer containing a structural unit represented by the following formula (1): １ is a fluorine-containing alkyl group having a branched structure, and R ２ is a hydrogen atom or a methyl group.

2. The above R １ 2. The fluorine-containing polymer according to claim 1, wherein the fluorine-containing alkyl group has 2 to 10 carbon atoms.

3. The above R １ (CF ３ ) ３ C- or (CF ３ ) ２ 3. The fluorine-containing polymer according to claim 1, which is CF-.

4. The fluoropolymer according to claim 1 or 2, wherein the proportion of the structural unit represented by formula (1) is 95 mass % or more.

5. A fluorine-containing monomer represented by the following formula (2): １ is a fluorine-containing alkyl group having a branched structure, and R ２ is a hydrogen atom or a methyl group.

6. An article having a film containing the fluoropolymer according to claim 1 or 2 on its surface.

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