Perfluorodiacyl peroxide, solution, polymerization initiator, method for producing polymer, and perfluoroacyl chloride

Abstract

A novel perfluorodiacyl peroxide is provided, which is represented by the following formula (1): (C5F 11 COO)2(1) The perfluorodiacyl peroxide is characterized by being represented by the following formula:

Description

Technical Field

[0001] The present disclosure relates to perfluorodiacyl peroxides, solutions, polymerization initiators, methods for producing polymers, and perfluoroacyl chlorides.

Background Art

[0002] Fluorine-based diacyl peroxides are known as polymerization initiators.

[0003] For example, Non-Patent Document 1 describes the synthesis of perfluorodiacyl peroxide from perfluoroacyl halide in the presence of H 2 O 2 and NaOH. In addition, Patent Document 1 describes that bis(perfluoro-n-butyryl) peroxide was obtained using perfluoro-n-butyryl chloride.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the present disclosure, Sufficient reactivity can be obtained even at low temperatures, and it is excellent in storage stability, safety, and handleability, and has a low environmental impact and is excellent in storage stability, safety, and handleability, and has a low environmental impact a method for producing a polymer using perfluorodiacyl peroxide using a solution as a polymerization initiator and is provided. 。

Means for Solving the Problems

[0007] The present disclosure provides a perfluorodiacyl peroxide characterized by being represented by the following formula (1): (C 5 F 11 COO) 2 (1) The present disclosure also provides a solution characterized by containing the perfluorodiacyl peroxide and a solvent.

[0008] The solvent is preferably a fluorine-containing solvent. The present disclosure further provides a polymerization initiator characterized by containing the perfluorodiacyl peroxide.

[0009] The present disclosure also provides a method for producing a polymer, characterized by including a step of polymerizing a radically polymerizable monomer using the perfluorodiacyl peroxide.

[0010] The present disclosure also provides a perfluoroacyl chloride characterized by being represented by the following formula (2):

[0011] C C 5 F 11 COCl (2)

Advantages of the Invention

[0012]

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present disclosure will be described.

[0014] The perfluorodiacyl peroxide of the present disclosure is represented by the following formula (1): (C 5 F 11 COO) 2 (1) The perfluorodiacyl peroxide of the present disclosure represented by the above formula (1) can be used, for example, as a polymerization initiator, a radical generator, a fluoroalkylating agent, a modifier, and the like. C 5 F 11 - in the above formula (1) may be branched or linear, but is usually linear.

[0015] The method for producing the perfluorodiacyl peroxide of the present disclosure is not limited, but it can be produced, for example, by the following method.

[0016] First, perfluorohexanoic acid and phosphorus oxychloride are mixed, and further N,N-dimethylformamide is mixed as a catalyst. Then, the obtained mixed solution is distilled to obtain the following formula (2): C 5 F 11 COCl (2) to obtain perfluoroacyl chloride represented by. Thereafter, sodium hydroxide, water, sodium chloride, and hydrogen peroxide solution are added to the flask, and perfluorohexane is added with stirring. The obtained reaction solvent is cooled to 4 to -5 °C, and a mixed solution of the perfluoroacyl chloride and perfluorohexane obtained above is added dropwise to the above reaction solvent in the range of 4 to -5 °C to obtain it. The perfluoroacyl chloride represented by the above formula (2) is also a novel compound provided by the present disclosure. The perfluoroacyl chloride represented by formula (2) is used as an intermediate for producing the perfluorodiacyl peroxide of the present disclosure. It can also be used as a perfluoroacylating agent.

[0017] Compounds can be synthesized using the perfluorodiacyl peroxide of the present disclosure. The present disclosure also provides compounds synthesized using the above perfluorodiacyl peroxide and a synthesis reaction using the perfluorodiacyl peroxide. Since the perfluorodiacyl peroxide of the present disclosure has the above structure, it is particularly suitable as a polymerization initiator, particularly as a polymerization initiator used for the polymerization of fluoromonomers. In the perfluorodiacyl peroxide represented by formula (1), the alkyl group bonded to the carbonyl group is C 5 F 11 By being this, compared with the conventionally known C 3 F 7 ones, it has the advantages of being more likely to undergo radical cleavage and being more likely to polymerize even at lower temperatures. Also, the conventionally known C 7 F 15 ones are not desirable for obtaining raw materials or for use from the perspective of environmental impact. The perfluorodiacyl peroxide represented by formula (1) of the present disclosure can obtain sufficient reactivity even at low temperatures, and is excellent in storage stability, safety, and handleability, and has little environmental impact, so it is an extremely useful compound.

[0018] The present disclosure provides a polymerization initiator characterized by containing the above perfluorodiacyl peroxide. The above polymerization initiator may be the above perfluorodiacyl peroxide alone or may be in the form of a solution described later, but it is preferably a solution from the perspective of safety.

[0019] The solution of the present disclosure contains the above perfluorodiacyl peroxide and a solvent.

[0020] In the solution of the present disclosure, the content of the above perfluorodiacyl peroxide may be appropriately set depending on the application used. For example, it can be 1 to 50% by mass based on the entire solution. When the solution of the present disclosure is used for the application of the polymerization initiator, the content of the perfluorodiacyl peroxide is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, based on the total amount of the solution.

[0021] The solvent is not limited as long as it can dissolve the perfluorodiacyl peroxide, and it may be a non-fluorinated solvent or a fluorinated solvent.

[0022] Examples of the non-fluorinated solvent include conventionally known solvents such as fluorine-free organic solvents such as alcohols, ethers, and ketones.

[0023] From the viewpoint of suppressing side reactions due to chain transfer, a fluorinated solvent is preferred as the solvent for the perfluorodiacyl peroxide. The fluorinated solvent has a fluorine atom in the molecule and is not particularly limited, but preferably has a boiling point of 25 to 100°C. The fluorinated solvent may be either aromatic or aliphatic. The fluorinated solvent is not particularly limited, and examples thereof include perfluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, fluorinated ethers, perfluoroperfluorobenzene, and the like. In particular, at least one selected from the group consisting of perfluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, and fluorinated ethers is preferred, perfluorocarbons, hydrofluorocarbons, and fluorinated ethers are more preferred, and hydrofluorocarbons and fluorinated ethers are even more preferred.

[0024] Examples of the perfluorocarbon include perfluorohexane, perfluoropentane, perfluoroheptane, perfluorooctane, and the like.

[0025] The fluorinated ether is not limited to the following general formula, and examples thereof include the following general formula (4): Rf-O-R (4) (In the formula, Rf represents a fluoroalkyl group or an alkyl group having 2 to 6 carbon atoms. R represents a fluoroalkyl group or an alkyl group having 1 to 4 carbon atoms. However, the total number of carbon atoms of Rf and R is 8 or less.) Examples thereof include fluorine-containing ethers represented by the formula.

[0026] In the general formula (4), Rf is preferably a fluoroalkyl group or an alkyl group having 2 to 5 carbon atoms, more preferably a fluoroalkyl group having 3 to 4 carbon atoms, and still more preferably a fluoroalkyl group having 4 carbon atoms. In addition, R in the general formula (4) is preferably a fluoroalkyl group or an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 2 carbon atoms, and still more preferably an alkyl group having 1 carbon atom. And the total number of carbon atoms of Rf and R in the formula (4) is preferably 3 to 7, more preferably 4 to 6, and still more preferably 5. The total number of fluorine atoms in the fluorine-containing ether is preferably 50% or more based on the total number of hydrogen atoms and fluorine atoms. More preferably, it is 60% or more, and still more preferably 70% or more.

[0027] Examples of the fluorine-containing ether include the following formula (5-1): F(CF 2 ) p O(CH 2 ) q H (5-1) (In the formula, p is an integer of 2 to 6. q is an integer of 1 to 4.) Fluorine-containing ethers represented by the formula, the following formula (5-2): H(CF 2 ) p O(CF 2 ) q F (5-2) (In the formula, p is an integer of 2 to 6. q is an integer of 1 to 4.) Fluorine-containing ethers represented by the formula, the following formula (5-3): H(CF 2 ) p O(CH 2 ) q H (5-3) (wherein p is an integer of 2 to 6, and q is an integer of 1 to 4), a fluorine-containing ether represented by the following formula (5-4): X(CF 2 ) p CH 2 O(CF 2 ) q H (5-4) (wherein X represents a fluorine atom or a hydrogen atom, p represents an integer of 1 to 5, and q represents an integer of 1 to 4), 3 ) 2 CHOCH 3 , (CF 3 ) 2 CFOCH 3 , CHF 2 CF 2 CH 2 OCF 2 CHF 2 , C.F. 3 CHFCF 2 OCH 3 , and CF 3 CHFCF 2 OCF 3 It is preferable that the material is at least one selected from the group consisting of: More preferably, C 4 F 9 OCH 3 , C 4 F 9 O.C. 2 H 5 , C 3 F 7 OCH 3 , (CF 3 ) 2 CFOCH 3 and more preferably C 4 F 9 OCH 3 It is.

[0028] The above fluorinated ether has a boiling point of preferably from -20 to 85°C, more preferably from 0 to 85°C, and further preferably from 4 to 85°C.

[0029] In addition to the perfluorodiacyl peroxide and the solvent, the solution of the present disclosure may contain other additives. Examples of the other additives include C 5 F 11 COOH, HC 6 F 12 COOH and the like. The content of the other additives is, for example, 0.1 to 30% by mass based on the entire solution.

[0030] The method for producing the polymer of the present disclosure includes a step of polymerizing a radically polymerizable monomer using the perfluorodiacyl peroxide. In such a method for producing a polymer, the perfluorodiacyl peroxide acts as a polymerization initiator.

[0031] The above polymer may be a crystalline polymer or an amorphous polymer. The above crystalline polymer is a polymer having a melting point due to the melting of crystals, and the amorphous polymer is a polymer that does not clearly have a melting point due to the melting of crystals. The perfluorodiacyl peroxide of the present disclosure is suitable for cases where a radical polymerization reaction is desired at a low temperature as a polymerization initiator for producing a resin, and is also suitable as a polymerization initiator for producing a resin in terms of having little chain transferability.

[0032] The radically polymerizable monomer is not limited, and conventionally known monomers can be employed. For example, it may be a non-fluorinated monomer such as ethylene or propylene, or a fluoromonomer such as tetrafluoroethylene, hexafluoropropylene, or alkyl vinyl ether.

[0033] The perfluorodiacyl peroxide has good affinity with a fluorine-containing solvent often used in the production of fluoropolymers and has low chain transferability. Therefore, it is particularly suitable as a polymerization initiator especially when polymerizing a fluoromonomer to produce a fluoropolymer.

[0034] The above polymerization may be solution polymerization, bulk polymerization, suspension polymerization, supercritical polymerization, emulsion polymerization, or the like.

[0035] The above fluoromonomer is not particularly limited. For example, tetrafluoroethylene [TFE], hexafluoropropylene [HFP], vinylidene fluoride [VdF], chlorotrifluoroethylene [CTFE], perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), ethylene trifluoride, vinyl fluoride, the following formula (6-1): CF 2 =CFO(CF 2 CF(Y)O) m (CF 2 ) n F (6-1) (In the formula, Y represents a fluorine atom or a trifluoromethyl group. m is an integer from 0 to 2. n is an integer from 1 to 4.) perfluoro(alkyl vinyl ether) represented by the following formula (6-2): CH 2 =CF(CF 2 ) n Z (6-2) (In the formula, Z represents a fluorine atom or a hydrogen atom. n is an integer from 1 to 8.) monomer represented by the following formula (6-3): CH 2 =CH(CF 2 ) n Z (6-3) (In the formula, Z represents a fluorine atom or a hydrogen atom. n is an integer from 1 to 8.) It preferably contains at least one fluoromonomer selected from the group consisting of monomers represented by the formula.

[0036] As the above fluoromonomer, a fluorine-containing monomer containing a hydrolyzable functional group can also be used. As the fluorine-containing monomer containing a hydrolyzable functional group, the following formula (7): CR 11 R 12 =CR 13 (CR 14 R 15 ) a-(O) b -R 10 -Z (7) (wherein R 11 ,R 12 ,R 13 ,R 14 and R 15 are the same or different and each represents F or a perfluoroalkyl group having 1 to 3 carbon atoms; R 10 represents a linear or branched perfluoroalkylene group having 1 to 8 carbon atoms which may have an oxygen atom in the main chain; a represents an integer of 0 to 6; b represents an integer of 0 or 1; and Z represents a hydrolyzable functional group.). The monomer represented by the formula is preferred. As the fluorine-containing monomer containing the above hydrolyzable functional group, those having the following structures (7-1) to (7-3) are more preferred. CF 2 =CF-(CF 2 ) c -Z (7-1) CF 2 =CF-(CF 2 C(CF 3 )F) d -Z (7-2) CF 2 =CF(CF 2 ) e -O-(CF 2 CFXO) f -(CF 2 ) g -Z (7-3) (In each formula, X represents F or -CF 3 ; c represents an integer of 0 to 8; d represents an integer of 1 to 2; e represents an integer of 0 to 2; f represents an integer of 0 to 3; g represents an integer of 1 to 8; and Z represents a hydrolyzable functional group.). As the above Z, -SO 2 F, -SO 2 Cl, -COOA 1 , -PO 3 A 2 A 3 (wherein A 1 represents a fluoroalkyl group; A 2 and A 3 are the same or different and each represents a fluoroalkyl group.) is preferred. As the fluorine-containing monomer containing the hydrolyzable functional group, those represented by the following formula are more preferable. CF 2 =CF-SO 2 F CF 2 =CFCF 2 -SO 2 F CF 2 =CFOCF 2 CF 2 SO 2 F CF 2 =CFOCF 2 CF 2 CF 2 CF 2 SO 2 F CF 2 =CFCF 2 OCF 2 CF 2 SO 2 F CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 SO 2 F CF 2 =CFOCF 2 CF 2 COOCH 3 CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 COOCH 3

[0037] As the fluoromonomer, a monomer having a ring structure or a cyclopolymerizable monomer may be used. For example, as the monomer having a ring structure, perfluoro(2,2-dimethyl-1,3-dioxole), perfluoro(1,3-dioxole), perfluoro(2-methylene-4-methyl-1,3-dioxolane), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole, etc. may be mentioned. Examples of the above-mentioned cyclic polymerizable monomer include perfluoro(3-butenyl vinyl ether), perfluoro[(1-methyl-3-butenyl)vinyl ether], perfluoro(allyl vinyl ether), 1,1-[(difluoromethylene)bis(oxy)][1,2,2-trifluoroethene], and the like.

[0038] In the above formula (6-1), m is preferably an integer of 0 or 1, more preferably 0. Further, n is preferably an integer of 1 to 3. In the above formula (6-2), Z is preferably a hydrogen atom. Further, n is preferably an integer of 1 to 6, more preferably an integer of 1 to 4. In the above formula (6-3), Z is preferably a fluorine atom. Further, n is preferably an integer of 1 to 6, more preferably an integer of 1 to 4.

[0039] The above-mentioned fluoropolymer is preferably a fluororesin. The above-mentioned fluororesin is not particularly limited as long as it has a polymerization unit based on a fluorine-containing monomer.

[0040] The above-mentioned fluoropolymer includes tetrafluoroethylene [TFE], hexafluoropropylene [HFP], vinylidene fluoride [VdF], chlorotrifluoroethylene [CTFE], (perfluoromethyl)vinyl ether, (perfluoroethyl)vinyl ether, (perfluoropropyl)vinyl ether, trifluoroethylene, vinyl fluoride, the following formula (6-1): CF 2 =CFO(CF 2 CF(Y)O) m (CF 2 ) n F (6-1) (In the formula, Y represents a fluorine atom or a trifluoromethyl group. m is an integer of 0 to 2. n is an integer of 1 to 4.) perfluoro(alkyl vinyl ether) represented by the following formula (6-2): CH 2 =CF(CF 2 ) nZ(6 - 2) (In the formula, Z represents a fluorine atom or a hydrogen atom. n is an integer from 1 to 8.) A monomer represented by the following formula (6 - 3): CH 2 =CH(CF 2 ) n Z(6 - 3) (In the formula, Z represents a fluorine atom or a hydrogen atom. n is an integer from 1 to 8.) It is preferably a fluoropolymer having a polymerization unit based on at least one fluoromonomer selected from the group consisting of monomers represented by the formula. In this specification, the polymerization unit based on a monomer refers to the form in which the carbon - carbon unsaturated double bond in the monomer molecule becomes a single bond.

[0041] The above fluoropolymer may have a polymerization unit based on a non - fluorinated monomer. It is also a preferred form that the above fluoropolymer has a polymerization unit based on at least one non - fluorinated monomer selected from the group consisting of ethylene [Et], propylene, 1 - butene, 2 - butene, alkyl vinyl ether, vinyl chloride, vinylidene chloride, and unsaturated carboxylic acid.

[0042] The above fluoropolymer is not particularly limited. Examples include polytetrafluoroethylene [PTFE], TFE / HFP copolymer, TFE / HFP - based copolymers such as TFE / HFP / perfluoro(alkyl vinyl ether) [FEP], TFE / perfluoro(alkyl vinyl ether) copolymer [PFA], Et / TFE copolymer [ETFE], TFE / HFP / VdF copolymer [THV], VdF / TFE copolymer [VT], polyvinylidene fluoride [PVdF], polychlorotrifluoroethylene [PCTFE], and CTFE / perfluoro(alkyl vinyl ether) / TFE copolymer [CPT], etc. As the fluoropolymer, a melt - processable fluoropolymer is more preferred.

[0043] The above ETFE preferably has a molar ratio of Et units:TFE units of 20:80 to 80:20. More preferably, the molar ratio of Et units:TFE units is 35:65 to 55:45. ETFE is a copolymer containing a polymerization unit based on TFE and a polymerization unit based on Et, and may have a polymerization unit based on other fluoromonomers or non-fluorinated monomers.

[0044] The above other fluoromonomers or non-fluorinated monomers are not particularly limited as long as they can be added to both Et and TFE, but fluorinated vinyl monomers having 3 to 10 carbon atoms are easy to use. For example, hexafluoroisobutylene, CH 2 =CFC 3 F 6 H, HFP, etc. are mentioned. Among them, the following formula (8): CH 2 =CH-Rf 4 (8) (In the formula, Rf 4 represents a perfluoroalkyl group having 4 to 8 carbon atoms.) The fluorinated vinyl monomer represented by is also one of the preferred forms. Also, as the non-fluorinated monomer, the following formula (9): CH 2 =CH-R 4 (9) (In the formula, R 4 is not particularly limited in terms of the number of carbon atoms, may contain an aromatic ring, and may contain a carbonyl group, an ester group, an ether group, an amide group, a cyano group, a hydroxyl group or an epoxy group. R 4 does not contain a fluorine atom.) A vinyl monomer represented by may also be used.

[0045] Also, ETFE is preferably one of the preferred forms as an Et / TFE / HFP copolymer [EFEP], and may further have polymerization units based on other fluoromonomers (excluding HFP) or non-fluorinated monomers. The other fluoromonomers and non-fluorinated monomers are preferably 10 mol% or less of the whole polymer, and more preferably 5 mol% or less. The molar ratio of Et units: TFE units: monomer units based on other fluoromonomers and non-fluorinated monomers is preferably 31.5 - 54.7:40.5 - 64.7:0.5 - 10.

[0046] In the above FEP, the HFP unit preferably exceeds 2% by mass and is 20% by mass or less, and more preferably 8 - 15% by mass.

[0047] As the perfluoro(alkyl vinyl ether) in the above PFA, those having an alkyl group with 1 to 6 carbon atoms are preferred, and perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether) or perfluoro(propyl vinyl ether) are more preferred. In the above PFA, the perfluoro(alkyl vinyl ether) unit preferably exceeds 2% by mass and is 15% by mass or less, and more preferably 2.5 - 8.0% by mass.

[0048] The above FEP or PFA may further be a polymer obtained by polymerizing other monomers as long as they have the above-described compositions respectively. As the other monomers, for example, in the case of the above FEP, perfluoro(alkyl vinyl ether) may be mentioned, and in the case of the above PFA, HFP may be mentioned. One or more of the above other monomers can be used.

[0049] The other monomers to be polymerized with the above FEP or PFA vary depending on the type, but are usually preferably 2% by mass or less of the resulting fluoropolymer. A more preferred upper limit is 1.5% by mass.

[0050] The content of each monomer unit of the copolymer described above can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and X-ray fluorescence analysis according to the type of monomer.

[0051] The above polymerization can be carried out in a polymerization solvent. The polymerization solvent is not particularly limited. For example, a non-fluorinated solvent exemplified as a solvent that can be used in the solution of the present disclosure may be used, or any fluorinated solvent may be used. From the viewpoint of efficiently producing a fluoropolymer, a fluorinated solvent is preferred.

[0052] As the above polymerization solvent, the fluorinated solvents described above are preferred, and at least one selected from the group consisting of perfluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, and fluorinated ethers is particularly preferred, perfluorocarbons, hydrofluorocarbons, and fluorinated ethers are more preferred, and hydrofluorocarbons and fluorinated ethers are even more preferred.

[0053] The process for producing the above polymer may be any process using the perfluorodiacyl peroxide of the present disclosure. By this polymerization process, a wet fluoropolymer in a wet state due to a polymerization solvent or the like can be obtained. That is, by the above polymerization reaction, a wet fluoropolymer containing a fluoropolymer and a solvent is obtained.

[0054] The above polymerization process can be carried out, for example, by charging a polymerization solvent, a fluoromonomer, and, if necessary, other additives into a reaction vessel, stirring the contents of the reaction vessel, maintaining the reaction vessel at a predetermined polymerization temperature, and then adding a predetermined amount of perfluorodiacyl peroxide to initiate the polymerization reaction. It is also possible to charge a surfactant, a chain transfer agent, a radical scavenger, etc. The polymerization may be a batch polymerization, a semi-batch polymerization, or a continuous polymerization. In addition, the reaction raw materials used in the polymerization reaction may be added intermittently or continuously after the start of the polymerization reaction. The above perfluorodiacyl peroxide may be dissolved in a polymerization solvent and then charged into the reaction vessel.

[0055] As the above chain transfer agent, for example, hydrocarbons such as isopentane, n-pentane, n-hexane, cyclohexane; alcohols such as methanol, ethanol; halogenated hydrocarbons such as carbon tetrachloride, chloroform, methylene chloride, methyl chloride, etc. can be used.

[0056] In the above polymerization reaction, the polymerization temperature is not particularly limited, but it is preferably 0 to 100°C, and more preferably 10 to 90°C. The polymerization pressure is also not particularly limited, but it is preferably 0.1 to 10 MPa, and more preferably 0.3 to 5 MPa. Note that the above polymerization temperature is the temperature of the solvent in the reaction vessel, and the above polymerization pressure is the pressure in the reaction vessel.

[0057] Using the perfluorodiacyl peroxide represented by the formula (1) of the present disclosure as a raw material, a novel compound can be produced. For example, by the methods described in JP-A-04-352769, JP-A-05-001066, Patent No. 3269135, JP-A-04-360891, JP-A-04-159273, JP-A-04-149192, Patent No. 3032781, Patent No. 2775913, JP-A-03-123751, JP-A-03-112951, etc., a novel compound can be produced by reacting the perfluorodiacyl peroxide represented by the formula (1) with other compounds. In addition, the perfluorodiacyl peroxide represented by the formula (1) can also be used as a modifier. For example, it can be adopted in the reactions described in JP-A-04-082860, JP-A-04-020527, JP-A-04-277586, JP-A-03-244631, JP-A-03-234706, JP-A-02-300208, etc.

Examples

[0058] Next, examples of the perfluorodiacyl peroxide of the present disclosure will be described, but the perfluorodiacyl peroxide of the present disclosure is not limited to such examples.

[0059] (Example 1) [Synthesis of Perfluoro-n-hexyl Chloride] 471 g (1.50 mol) of perfluoro-n-hexanoic acid was placed in a 500 ml flask equipped with a mechanical stirrer, thermometer, dropping funnel, distillation condenser, and exhaust tube, and 161 g (1.05 mol) of phosphorus oxychloride was added dropwise at room temperature over 2 minutes while stirring. No exotherm was observed at that time. After the addition, 55 g (0.75 mol) of dimethylformamide (DMF) was added dropwise at 5 °C over 5 minutes. At that time, almost no generation of white smoke or exotherm was observed. After completion of the dropwise addition, the temperature of the bath for heating the flask was raised to 110 °C, and distillation was carried out through a KIRIYAMA Pac distillation column manufactured by Kiriyama Seisakusho. The obtained product was a colorless liquid, and the yield was 449 g (yield 90%). 19 The purity of the product was determined by 19F-NMR to be 99%. The product showed an absorption of carbonyl at 1790 cm -1 in the infrared absorption spectrum. From the above 19 19F-NMR, infrared absorption spectrum, and elemental analysis, it was confirmed that the obtained product was perfluoro-n-hexyl chloride.

[0060] (Example 2) [Synthesis of Bis(perfluoro-n-hexyl) Peroxide] 8.8 g (0.22 mol) of sodium hydroxide was placed in a 500 ml flask equipped with a mechanical stirrer, thermometer, and dropping funnel, 165.0 g of water was added and dissolved, and 8.2 g of sodium chloride was added. 7.5 g (0.11 mol) of 50% hydrogen peroxide solution was added, and after adding 142 g of perfluorohexane with stirring, the reaction solution was cooled to -5 °C. After cooling, a mixed solution of 43.16 g (0.13 mol) of perfluoro-n-hexyl chloride with a purity of 99% obtained from Example 1 and 36 g of perfluorohexane was added dropwise in the range of -2 to -5 °C. Aging was carried out for 60 minutes. After separation and washing with water, drying was performed using magnesium sulfate. Bis(perfluoro-n-hexyl) peroxide was obtained with a yield of 195 g, a yield rate of 48%, and a purity of 10.0 wt%. The analysis method of the peroxide was carried out according to "New Experimental Science Course 15 Oxidation and Reduction [I-2] 11·3·3 Analysis Method of Peroxides: Iodine Titration Method", and the above-mentioned yield rate and purity were calculated.

[0061] (Example 3) 1095 g of distilled water was charged into an autoclave with an internal volume of 4.1 L. After sufficient nitrogen substitution, 1133 g of hexafluoropropylene (HFP) was charged, and 12.3 g of perfluoro(propyl vinyl ether) (PPVE) was charged. The inside of the system was maintained at 32 °C and a stirring speed of 580 rpm. Then, 120 g of tetrafluoroethylene (TFE) was charged, and then 9.6 g of the peroxide solution synthesized in Example 2 was added to initiate polymerization. Every 2 hours, 9.6 g of the peroxide solution synthesized in Example 2 was additionally added to continue the polymerization. As the polymerization progressed, the pressure inside the system decreased, so tetrafluoroethylene (TFE) was continuously supplied to maintain the pressure inside the system at 1.02 MPa. When a total of 171 g of tetrafluoroethylene (TFE) was charged, the reaction was terminated. The reaction time was 4.5 hours. After the polymerization was completed, the gas inside the system was released until the pressure returned to normal pressure, and after nitrogen substitution, the autoclave was opened, and the white polymer powder was taken out and dried in an electric furnace at 150 °C for 12 hours. The obtained polymer was 193 g. 19 The result of the composition analysis by F-NMR was a copolymer of TFE 88.4 wt%, HFP 10.3 wt%, and PPVE 1.3 wt%. The melt flow rate measured at 372 °C was 7.9 g / 10 min. The above melt flow rate was measured according to ASTM D-1238, with a die diameter of 2.1 mm and a length of 8 mm, at 372 °C and a load of 5 kg.

Claims

1. The following formula (1): (C ５ F １１ COO) ２ (1) represented by, wherein C ５ F １１ -group is a linear perfluorodiacyl peroxide, and At least one fluorinated solvent selected from the group consisting of perfluorocarbons, hydrofluorocarbons, and fluorinated ethers, contains a solution containing the boiling point of the fluorinated solvent is 25 to 100 ° C, using a polymerization initiator in which the content of the perfluorodiacyl peroxide is 5 to 30% by mass based on the whole solution, including a step of polymerizing a fluoromonomer containing tetrafluoroethylene to produce a fluoropolymer, The polymerization is a suspension polymerization in which tetrafluoroethylene is continuously added to a reaction vessel, and a method for producing a polymer characterized by this.

2. The method for producing a polymer according to claim 1, wherein the fluoromonomer contains at least one fluoromonomer selected from the group consisting of hexafluoropropylene, chlorotrifluoroethylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), and perfluoro(propyl vinyl ether).

3. The method for producing a polymer according to claim 1 or 2, characterized in that the polymerization initiator is divided and additionally charged during the polymerization reaction.