JP2017057379A - Manufacturing method of fluoropolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel manufacturing method for manufacturing a fluoropolymer by polymerizing tetrafluoroethylene and vinylidene fluoride.SOLUTION: There is provided a manufacturing method of a fluoropolymer including a process for polymerizing tetrafluoroethylene and vinylidene fluoride in presence of a surfactant and an aqueous medium, wherein the surfactant is a mixture or the like of a fluorine-containing allyl ether compound represented by the formula:CX=CFCF-O-(CF(CF)CFO)-CF(CF)-Y, where each X is the same or different and represent F or H, n represents 0 or an integer of 1 to 10, Y represents -SOM or -COOM and M represents H, NHor an alkali metal and a fluorine-containing anionic surfactant having 7 or less carbon atoms.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a fluoropolymer.

As a method for producing a fluoropolymer by polymerizing a fluoromonomer in the presence of a surfactant, the following method is known.

Patent Document 1 discloses a method for producing a fluorine-containing polymer by radical polymerization of a fluorine-containing monomer in an aqueous medium, wherein the radical polymerization includes a fluorine-containing vinyl group having a radical polymerizable unsaturated bond and a hydrophilic group. In the presence of the containing compound (1) and the fluorine-containing compound (2) having a fluorocarbon group and a hydrophilic group in which carbon atoms directly bonded with fluorine atoms are bonded in the range of 1 to 6 A method for producing a fluorine-containing polymer is described.

Patent Document 2 discloses a method for producing a fluorine-containing polymer by radical polymerization of a fluorine-containing monomer in an aqueous medium, wherein the radical polymerization is represented by the following general formula CX ₂ = CFCF ₂ —O— (CF (CF _{3 ) CF 2 O) n -CF (} CF 3) -Y
(In the formula, each X is the same and represents F or H. n represents 0 or an integer of 1 to 10, Y represents —SO ₃ M or —COOM, and M represents H, NH. ₄ or an alkali metal.) And a fluorine-containing anionic surfactant (2) having 7 or less carbon atoms (provided that the fluorine-containing allyl ether compound (1) The method for producing a fluorine-containing polymer, which is carried out in the presence of

Patent Document 3 discloses a method of producing a melt-processable fluorine-containing polymer by radical polymerization of a fluorine-containing monomer in an aqueous medium, wherein the radical polymerization has 1 to 6 carbon atoms directly bonded with fluorine atoms. A melt-processable fluorine-containing polymer production method is described which is carried out in the presence of a fluorine-containing compound having a fluorocarbon group and a hydrophilic group that are continuously bonded in the above range.

In Patent Document 4, (a) an aqueous mixture containing a surfactant and a radical initiator is contacted with a monomer feed containing one or more fluoromonomers,
(B) providing sufficient heat and agitation to effect polymerization of the one or more fluoromonomers, thereby forming a fluoropolymer dispersion, and (c) separating the fluoropolymer from the dispersion. In a method for producing a fluoropolymer comprising:
The surfactant is a C ₇ -C ₂₀ linear 1-alkane sulfonate, a C ₇ -C ₂₀ linear 2-alkane sulfonate, a C ₇ -C ₂₀ linear 1,2-alkane disulfonate, and An alkanesulfonate selected from a mixture thereof, wherein the fluoropolymer is inelastic, contains at least 71% by weight of vinylidene fluoride, and has a crystalline polyvinylidene fluoride content of at least 2% A process for producing a fluoropolymer is described.

Patent Document 5 discloses a method for producing a polymer in an aqueous reaction medium,
(A) forming an aqueous emulsion comprising at least one radical initiator, at least one non-fluorinated surfactant and at least one monomer; and (b) initiating polymerization of said monomer:
Including
A process is described wherein the non-fluorinated surfactant is selected from the group consisting of polyvinylphosphonic acid, polyacrylic acid, polyvinylsulfonic acid and salts thereof.

Patent Document 6 discloses a method for producing a fluoropolymer, comprising at least one fluoromonomer, a non-fluorinated, nonionic emulsifier containing polyethylene glycol and / or polypropylene glycol segments having 2 to 200 repeating units. A process comprising polymerizing in an aqueous medium comprising at least one emulsifier is described.

Patent Document 7 discloses a method for producing a (per) fluoropolymer, the method comprising polymerizing one or more fluorinated monomers in the presence of a multiphase medium, wherein the medium comprises:
(A) an aqueous phase [phase (W)];
_{(B) Rf- (OCF 2 CF} 2) k-1 -O-CF 2 -COOX a (I)
At least one fluorinated surfactant having the formula (I) [surfactant (FS)], wherein Rf is a C ₁ -C ₃ perfluoroalkyl group optionally containing one or more ether oxygen atoms. There, k is 2 or 3, _{X a} is selected from ammonium groups monovalent metal and wherein ^NR _{N 4,} equal or different ^{R N} at each occurrence in this formula, a hydrogen atom or a _C 1 -C ₃ alkyl Group);
(C)-at least one nonfunctional (per) fluoropolyether (nonfunctional PFPE) comprising at least one (per) fluoropolyoxyalkylene chain [chain (RF)];
At least one functionality comprising at least one (per) fluoropolyoxyalkylene chain [chain (R′F)] and having a number average molecular weight of at least 1000 and a solubility of less than 1% by weight in water at 25 ° C. A per) fluoropolyether (functional PFPE); and an oil phase [phase (O)];
A method is described that includes:

Patent Document 8 discloses a method for producing a dispersion of a vinylidene fluoride (VDF) thermoplastic polymer [polymer (F)],
-At least one surfactant selected from the group consisting of a non-fluorinated surfactant [surfactant (HS)] and a fluorinated surfactant having a molecular weight of less than 400 [surfactant (FS)];
At least one (per) fluoropolyoxyalkylene chain [chain (R ′ _F )] and at least one functional (per) fluoropolyether (functional PFPE) comprising at least one functional group, The functional PFPE has a number average molecular weight of at least 1000 and a solubility in water of less than 1% by weight at 25 ° C., and the functional PFPE is present in the aqueous phase in an amount of 0.001 to 0.3 g / l. A method is described which comprises polymerizing VDF in the aqueous phase comprising a functional PFPE.

Patent Document 9 discloses a method for polymerizing a fluoromonomer in a polymerization reactor to form a dispersion of fluoropolymer particles in an aqueous medium, the method comprising an initial period, and an initial period. Including a subsequent stabilization period, wherein the initial period includes preparing an initial dispersion of fluoropolymer particles in the aqueous medium in the polymerization reactor, wherein the stabilization period includes a fluoromonomer in the polymerization reactor. A method is described which includes a step of polymerizing a hydrocarbon, a step of adding a hydrocarbon-containing surfactant to the polymerization reactor, and a step of deactivating the hydrocarbon-containing surfactant.

International Publication No. 2008/001894 JP 2010-235667 A JP 2009-155558 A JP 2005-314699 A Special table 2009-504841 Special table 2008-554388 gazette Special table 2013-514413 gazette Special table 2013-514407 gazette Special table 2013-542308 gazette

An object of the present invention is to provide a novel production method for producing a fluoropolymer by polymerizing tetrafluoroethylene and vinylidene fluoride.

The present invention is a method for producing a fluoropolymer comprising a step of polymerizing tetrafluoroethylene and vinylidene fluoride in the presence of a surfactant and an aqueous medium, wherein the surfactant comprises the following (A) to (F And at least one selected from the group consisting of:

Surfactant (A)
_{Formula: CX 2 = CFCF 2 -O- (} CF (CF 3) CF 2 O) n -CF (CF 3) -Y
(In the formula, each X is the same or different and represents F or H. n represents 0 or an integer of 1 to 10, Y represents —SO ₃ M or —COOM, and M represents H, NH ₄ or an alkali metal)) and a fluorine-containing anionic surfactant having 7 or less carbon atoms (excluding the above fluorine-containing allyl ether compound)

Surfactant (B)
A group consisting of linear 1-alkanesulfonic acid having 7 to 20 carbon atoms, linear 2-alkanesulfonic acid having 7 to 20 carbon atoms, linear 1,2-alkanedisulfonic acid having 7 to 20 carbon atoms, and salts thereof. At least one alkanesulfonic acid or salt thereof selected from

Surfactant (C)
At least one non-fluorinated surfactant selected from the group consisting of polyvinylphosphonic acid, polyacrylic acid, polyvinylsulfonic acid and salts thereof

Surfactant (D)
Surfactant having at least one repeating unit selected from the group consisting of —CH ₂ CH ₂ O— and —CH ₂ CH ₂ CH ₂ O—, and having 2 to 100 repeating units

Surfactant (E)
At least one surfactant selected from the group consisting of non-fluorinated surfactants and fluorinated surfactants having a molecular weight of less than 400, and a functional fluoropoly comprising a fluoropolyoxyalkylene chain and a functional group ether

Surfactant (F)
Deactivated hydrocarbon-containing surfactant

In the said manufacturing method, it is further preferable to superpose | polymerize the at least 1 sort (s) of ethylenically unsaturated monomer selected from the group which consists of an ethylenically unsaturated monomer represented by Formula (1) and Formula (2).
Formula (1): CX ¹¹ X ¹² = CX ¹³ (CX ¹⁴ X ¹⁵ ) _n11 X ¹⁶
(In the formula, X ^{11 to} X ¹⁶ are the same or different and represent H, F or Cl, and n ¹¹ represents an integer of 0 to 8, except for tetrafluoroethylene and vinylidene fluoride.)
Equation ^{(2): CX 21 X 22} = CX 23 -O (CX 24 X 25) n21 X 26
(Wherein X ^{21 to} X ²⁶ are the same or different and represent H, F or Cl, and n ²¹ represents an integer of 0 to 8)

The fluoropolymer preferably contains more than 50 mol% tetrafluoroethylene units of all monomer units constituting the fluoropolymer.

According to the production method of the present invention, a fluoropolymer can be produced with high productivity.

Hereinafter, the present invention will be specifically described.

The production method of the present invention is a fluoropolymer production method including a step of polymerizing tetrafluoroethylene and vinylidene fluoride in the presence of a surfactant and an aqueous medium. As the surfactant, (A) to (F) ) Is characterized by using at least one selected from the group consisting of: Any of these surfactants may be added before the polymerization, may be added after the start of the polymerization, may be added continuously during the polymerization, or divided before and during the polymerization. May be added.

Surfactant (A)
Surfactant (A) has the formula:
_{CX 2 = CFCF 2 -O- (CF} (CF 3) CF 2 O) n -CF (CF 3) -Y
(In the formula, each X is the same or different and represents F or H. n represents 0 or an integer of 1 to 10, Y represents —SO ₃ M or —COOM, and M represents H, NH ₄ or an alkali metal.) And a fluorine-containing anionic surfactant having 7 or less carbon atoms (excluding the above-mentioned fluorine-containing allyl ether compound). .

As n, the integer of 0-5 is preferable at the point of emulsification ability, the integer of 0-2 is more preferable, 0 or 1 is still more preferable, and 1 is especially preferable. Y is preferably -COOM in that moderate water solubility and surface activity can be obtained. M is preferably H or NH _{4 and} more preferably NH _{4 in} that it hardly remains as an impurity and improves the heat resistance of the obtained molded body.

Examples of the fluorine-containing allyl ether compound include the following formula:

In the compounds _{represented, CH 2 = CFCF 2 -O- (} CF (CF 3) CF 2 O) -CF (CF 3) -COONH 4 is more preferable.

Examples of the fluorine-containing anionic surfactant include:
Rf ^a1 -Y ^a
(In the formula, Rf ^a1 represents ^a C 2-6 linear or branched fluoroalkyl group into which a divalent oxygen atom may be inserted, and Y ^a represents —COOM, —SO ₃ M, —SO ₂ represents NM ₂ or —PO ₃ M _2, and M represents H, NH _4, or an alkali metal).

As Y ^a , —COOH, —COONa or —COONH ₄ is preferable, and —COONH ₄ is more preferable.

The fluorine-containing anionic surfactant is represented by the formula: CF _3- (CF ₂ ) _na1 -Y ^a
( ^Wherein n ^a1 represents an integer of ¹ to 5, and Y ^a is the same as described above), or
Formula: Rf ^a2 O—Rf ^a3 O—Rf ^a4 —Y ^a
(Wherein Rf ^a2 represents a fluoroalkyl group having 1 to 3 carbon atoms, Rf ^a3 and Rf ^a4 independently represent a linear or branched fluoroalkylene group having 1 to 3 carbon atoms, Rf ^a2 , Rf ^a3 and Rf ^a4 has a total of 6 or less carbon atoms, and Y ^a is the same as described above.

_{Examples of the} fluorine-containing anionic surfactant represented by the formula: CF _3- (CF ₂ ) _{na 1} -Y ^a include CF ₃ (CF ₂ ) ₄ COONH ₄ , CF ₃ (CF ₂ ) ₃ COONH ₄ , CF ₃ (CF ₂ ) ₂ COONH ₄ , CF ₃ (CF ₂ ) ₃ SO ₃ Na, CF ₃ (CF ₂ ) ₃ SO ₂ NH _{2 and the} like.

As the fluorine-containing anionic surfactant represented by the formula: Rf ^a2 O—Rf ^a3 O—Rf ^a4 —Y ^a ,
_{Formula: CF 3 O-CF (CF} 3) CF 2 O-CX a (CF 3) -Y a
(Wherein X ^a represents H or F, and Y ^a is the same as above), a fluorine-containing anionic surfactant represented by:
_{Formula: CF 3 O-CF 2 CF} 2 CF 2 O-CFX a CF 2 -Y a
(Wherein X ^a represents H or F, and Y ^a is the same as above), a fluorine-containing anionic surfactant represented by:
_{Formula: CF 3 CF 2 O-CF} 2 CF 2 O-CFX a -Y a
(Wherein, X ^a represents H or F, and Y ^a is the same as described above).

The amount of the fluorine-containing allyl ether compound used is preferably 1 to 300 ppm of the aqueous medium, more preferably 5 ppm or more, further preferably 10 ppm or more, more preferably 200 ppm or less, still more preferably 100 ppm or less.

The amount of the fluorine-containing anionic surfactant used is preferably 100 to 50000 ppm of the aqueous medium, more preferably 200 ppm or more, further preferably 300 ppm or more, particularly preferably 400 ppm or more, more preferably 10,000 ppm or less, and 5000 ppm or less. More preferred is 2000 ppm or less.

Surfactant (B)
The surfactant (B) is a linear 1-alkanesulfonic acid having 7 to 20 carbon atoms, a linear 2-alkanesulfonic acid having 7 to 20 carbon atoms, or a linear 1,2-alkanedisulfone having 7 to 20 carbon atoms. It is at least one alkanesulfonic acid selected from the group consisting of acids and salts thereof or a salt thereof. Surfactant (B) is a non-fluorinated surfactant.

As said alkanesulfonic acid or its salt, it is preferable that all are C8-C12.

The alkane sulfonate may be an alkali metal salt, an ammonium salt or a monoalkyl, dialkyl, trialkyl or tetraalkyl substituted ammonium salt. Among these, an ammonium salt, a sodium salt or a potassium salt is preferable, and an ammonium salt is more preferable.

As the surfactant (B), linear 1-octanesulfonic acid, linear 2-octanesulfonic acid, linear 1,2-octanedisulfonic acid, linear 1-decanesulfonic acid, linear 2-decanesulfonic acid , Linear 1,2-decanedisulfonic acid, linear 1,2-dodecanedisulfonic acid, linear 1-dodecanesulfonic acid, linear 2-dodecanesulfonic acid, linear 1,2-dodecanedisulfonic acid and salts thereof More preferred is at least one selected from the group consisting of

As the surfactant (B), 1-octanesulfonic acid, 2-octanesulfonic acid, 1,2-octanedisulfonic acid, 1-decanesulfonic acid, 2-decanesulfonic acid, 1,2-decanedisulfonic acid, 1 More preferred is at least one selected from the group consisting of -dodecanesulfonic acid, 2-dodecanesulfonic acid, 1,2-dodecanedisulfonic acid and salts thereof.

As the usage-amount of surfactant (B), 0.001-2 mass% is preferable with respect to the quantity of all the monomers to superpose | polymerize, and 0.5 mass% or less is more preferable.

Surfactant (C)
Surfactant (C) is at least one non-fluorinated surfactant selected from the group consisting of polyvinyl phosphonic acid, polyacrylic acid, polyvinyl sulfonic acid and salts thereof. These are all water-soluble or water-dispersible low molecular weight molecules.

The salt may be an ammonium salt or a sodium salt.

The polyacrylic acid may be polyacrylic acid or polymethacrylic acid.

The polyvinyl phosphonic acid, polyacrylic acid and polyvinyl sulfonic acid may be a copolymer of the acid and one or more other ethylenically unsaturated monomers. However, the copolymer is water soluble or water dispersible.

Other co-surfactants may be used with the surfactant (C). The co-surfactant is preferably at least one selected from the group consisting of non-fluorinated hydrocarbon surfactants and siloxane surfactants.

As the usage-amount of surfactant (C), 0.001-2 mass% is preferable with respect to the quantity of all the monomers to superpose | polymerize, and 0.5 mass% or less is more preferable.

Surfactant (D)
The surfactant (D) has at least one repeating unit selected from the group consisting of —CH ₂ CH ₂ O— and —CH ₂ CH ₂ CH ₂ O—, and has 2 to 100 repeating units. A surfactant.

The number of repeating units is preferably 3 or more, more preferably 5 or more, and preferably 50 or less.

The surfactant (D) is preferably at least one selected from the group consisting of polyethylene glycol acrylate, polyethylene glycol, polyethylene glycol phenol oxide, polypropylene glycol acrylate and polypropylene glycol.

Surfactant (D) contains hydroxyl, carboxylate, benzoate, sulfonic acid, phosphonic acid, acrylate, methacrylate, ether, hydrocarbon, phenol, functionalized phenol, ester, fatty ester, etc. at the polymer main chain terminal. Can do. This end group can contain halogen atoms such as F, Cl, Br and I, and can also contain other groups or functional groups such as amines, amides, hydrocarbons, etc. For example, polyethylene glycol having a phenol oxide end group can be mentioned.

The surfactant (D) is preferably a non-fluorinated nonionic surfactant.

The amount of the surfactant (D) used is preferably 100 ppm to 2% by mass, more preferably 1% by mass or less, and more preferably 0.5% by mass or less based on the mass of the obtained fluoropolymer.

Surfactant (E)
The surfactant (E) is at least one surfactant selected from the group consisting of a non-fluorinated surfactant and a fluorinated surfactant having a molecular weight of less than 400, and a functional group that is functional with a fluoropolyoxyalkylene chain. And a mixture of functional fluoropolyethers containing groups.

The non-fluorinated surfactant is preferably a non-fluorinated anionic surfactant selected from the group consisting of sulfonic acid, phosphonic acid, carboxylic acid and salts thereof. The salt may be an alkali metal salt, an ammonium salt, or a monoalkyl, dialkyl, trialkyl or tetraalkyl substituted ammonium salt. Among these, an ammonium salt, a sodium salt or a potassium salt is preferable, and an ammonium salt is more preferable.

The non-fluorinated surfactant is more preferably at least one selected from the group consisting of alkane sulfonates and salts thereof, straight chain 1-alkane sulfonates having 7 to 30 carbon atoms, 2-carbon having 7 to 20 carbon atoms. More preferable is at least one selected from the group consisting of alkanesulfonates, linear 1,2-alkanedisulfonates having 7 to 20 carbon atoms, and salts thereof.

Examples of the non-fluorinated surfactant include 1-octane sulfonate, 2-octane sulfonate, 1,2-octane disulfonate, 1-decane sulfonate, 2-decane sulfonate, 1,2-decane disulfonate, 1-dodecane sulfonate. , 2-dodecanesulfonate, 1,2-dodecanedisulfonate, and at least one selected from the group thereof are particularly preferred.

The non-fluorinated surfactant is more preferably at least one selected from the group consisting of alkyl sulfates and salts thereof. Among them, straight chain 1-alkyl sulfate having 7 to 20 carbon atoms, straight chain 2-alkyl sulfate having 7 to 20 carbon atoms, straight chain 1,2-alkyl disulfate having 7 to 20 carbon atoms, and their One type of the scuff film selected from the group consisting of salts is more preferable.

Examples of the non-fluorinated surfactant include 1-octyl sulfate, 2-octyl sulfate, 1,2-octyl disulfate, 1-decyl sulfate, 2-decyl sulfate, 1,2-decyl disulfate. Particularly preferred is at least one selected from the group consisting of fete, 1-dodecyl sulfate, 2-dodecyl sulfate, 1,2-dodecyl disulfate and salts thereof.

The fluorinated surfactant is a surfactant having a molecular weight of less than 400 and a low environmental load.

As the fluorinated surfactant,
Formula: Rf ^e1 — (OCF ₂ CF ₂ ) _k−1 —O—CF ₂ —COOX ^e1
Wherein Rf ^e1 is a ^C 1-3 perfluoroalkyl group that may contain an ether bond, k is 2 or 3, and X ^e1 is a monovalent metal or of formula NR ^e1 ₄ A surfactant represented by the following formula: an ammonium group, and R ^e1 is independently H or an alkyl group having 1 to 3 carbon atoms,
Formula: Rf ^e2 O—CF ₂ CF ₂ —O—CF ₂ —COOX ^e2
(In the formula, Rf ^e2 is a perfluoroalkyl group having 1 to 3 carbon atoms, X ^e2 is Li, Na, K, NH ₄ or NR ^e2 ₄ , and R ^e2 is an alkyl group having 1 to 3 carbon atoms. Is more preferable,
_{Formula: CF 3 CF 2 O-CF} 2 CF 2 -O-CF 2 -COOX e2
It is more preferable that the surfactant is represented by the formula (wherein ^Xe2 is the same as above).

The fluorinated surfactant also has the formula:

(In the formula, X ^e3 , X ^e4 and X ^e5 are each independently a (per) fluoroalkyl group having 1 to 6 carbon atoms which may contain H, F or an oxygen atom, and Rf ^e3 has 1 carbon atom. To 3 perfluoroalkylene groups, L ^e represents a single bond or a divalent organic group, Y ^e1 represents —SO ₃ X ^e6 , —PO ₃ X ^e6 ₂ or —COOX ^e6 (X ^e6 represents a monovalent group). It is also preferably a surfactant represented by a metal or an ammonium group of the formula NR ^e6 ₄ , where R ^e6 is independently H or an alkyl group having 1 to 3 carbon atoms.

^Le is a single bond, or —O (Rf ^e4 CF ₂ O) _k−1 —O—Rf ^e5 — (Rf ^e4 is a perfluoroalkylene group having 1 to 3 carbon atoms, and Rf ^e5 is a divalent organic group). It is preferable that k is preferably 1, and Rf ^e5 is preferably —CFRf ^e6 — or —CF ₂ CFRf ^e6 — (Rf ^e6 is F or CF ₃ ).
Y ^e1 is preferably —COOX ^e6 .
X ^e5 is preferably H or F.
X ^e3 and ^{X e4} is, F independently a ^{-Rf e7} or-ORF ^e7, it is preferred ^{Rf e7} is a perfluoroalkyl group having 1 to 3 carbon atoms. At least one of X ^e3 and ^{X e4} is preferably ^{-Rf e7} or-ORF ^e7.
Rf ^e3 is ^-CX e7 ^X e8 - ^{(a X e7} and ^{X e8} is F independently, ^{-Rf e8} or -ORf ^{e8, Rf e8} is a perfluoroalkyl group having 1 to 3 carbon atoms) is preferably.

As the surfactant represented by the above formula,

Etc.

As the fluorinated surfactant,
Formula: R ^e10 -E-Y ^e2
Wherein Y ^e2 is —SO ₃ X ^e9 , —PO ₃ X ^e92 ₂ or —COOX ^e9 (X ^e9 is a monovalent metal or an ammonium group of formula NR ^e4 ₄ and R ^e4 is independently H or E is a non-fluorinated hydrocarbon group having 4 to 24 carbon atoms which may contain an ether bond, and R ^e10 is —ORf ^e9 , —N ( Rf ^e9 ) ₂ or —OAr (Rf ^e9 ) _r , Rf ^e9 is independently a C 1-6 perfluoroalkyl group, Ar is an aromatic moiety (eg, phenyl group), and r is 1 It is also preferable that it is a surfactant represented by

Y ^e2 is preferably —SO ₃ X ^e9 .
E is _{- (CH 2) ne - (} n e is an integer of 4 to 20) is preferably.
R ^e10 is preferably —OCF ₃ , —N (CF ₃ ) ₂ or —O—Ph—CF ₃ (Ph is an aromatic ring of —C ₆ H ₄ —).

The functional fluoropolyether (functional PFPE) includes a fluoropolyoxyalkylene chain and a functional group.

The fluoropolyoxyalkylene chain is preferably a perfluorooxyalkylene chain.
The fluoropolyoxyalkylene chain has the formula: — (CF ₂ ) _j —CFZ ^e O— (wherein Z ^e is F or a (per) fluoro (oxy) alkyl group having 1 to 5 carbon atoms, j is 0 to 0) It is preferred to include one or more repeating units having an integer of 3. This repeat unit is generally statistically distributed along the fluoropolyoxyalkylene chain.

The functional PFPE preferably has a number average molecular weight of at least 1000 and a solubility in water of less than 1% by weight at 25 ° C.
The solubility is more preferably less than 0.5% by weight, and still more preferably less than 0.1% by weight.
The number average molecular weight is more preferably 1300 or more, and further preferably 1500 or more. The number average molecular weight (Mn) is expressed by the formula: Mn = ΣM _i · N _i / ΣN _i (N _i is the number of molecules having the average molecular weight M _i ).

The functional PFPE preferably contains at least one functional group selected from the group consisting of a carboxylic acid group, a phosphonic acid group, a sulfonic acid group, and an acid salt group thereof.

As the functional PFPE,
^{_{Wherein: T 1 - (CFW 1)}} p1 -O-Rf e10 - (CFW 2) p2 -T 2
( ^Wherein Rf ^e10 is the fluoropolyoxyalkylene chain described above, and T ₁ and T ₂ are independently a carboxylic acid group, a phosphonic acid group, a sulfonic acid group, and an acid salt group thereof, and And at least one selected from the group consisting of (per) fluoroalkyl groups having 1 to 3 carbon atoms which may contain F, Cl, and Cl, and any one of T ₁ and T ₂ is the functional group described above. And W ₁ and W ₂ are independently F or CF ₃ , and p 1 and p 2 are independently an integer of 1 to 3).

When W ₁ and / or W ₂ is CF ₃ , p 1 and p 2 are preferably 1.
Both T ₁ and T ₂ are preferably the functional groups described above.

As the functional PFPE,
^{_{Formula: X e10 OOC-CFW 1 -O}} -Rf e10 -CFW 2 -COOX e10
( ^Wherein Rf ^e10 , W ₁ and W ₂ are as described above, X ^e10 is a monovalent metal or an ammonium group of formula NR ^e10 ₄ , and R ^e10 is independently H or C 1-6. A hydrocarbon group is more preferable,
_{^{Wherein: X e10 OOC-CF 2 -O-}} (CF 2) n '(CF 2 CF 2 O) m' -CF 2 -COOX e10
Wherein n ′ and m ′ are independently integers greater than 0 such that the number average molecular weight of the functional PFPE is at least 1000, preferably at least 1300, more preferably at least 1500, More preferably, it is generally statistically distributed along the perfluoropolyoxyalkylene chain, and ^Xe10 is as described above.

The amount of the non-fluorinated surfactant and / or the fluorinated surfactant used is preferably 0.01 to 10 g / L of the aqueous medium in total.

The amount of the functional PFPE used is preferably 0.001 to 0.3 g / L of the aqueous medium, more preferably 0.15 g / L or less, still more preferably 0.1 g / L or less, and 0.005 g / L. The following are particularly preferred:

Surfactant (F)
Surfactant (F) is a deactivated hydrocarbon-containing surfactant.

The hydrocarbon-containing surfactant may be cationic, nonionic or anionic, but is preferably anionic.

Examples of the hydrocarbon-containing surfactant include the formula: R ^g -L ^g -M ^g (wherein R ^g is a linear alkyl group having 6 to 17 carbon atoms, L ^g is -ArSO _3- , _{-SO 3 -, - SO 4 -} , - PO 3 - and at least one selected from the group consisting of -COO-, ^{M g} is a monovalent cation, Ar is represented by an arylene group) Anionic surfactants are preferred,
_{Formula: CH 3} - _(CH 2) in ng ^{-L g} -M g (wherein, ^{n g} represents an integer of 5 to 16, ^{L g} is _{-SO 3} -, - PO 3 - and the group consisting of -COO- It is at least one selected from, M ^g anionic surface active agents represented by the same) and the more preferable.

M ^g is preferably H, Na, K or NH ₄ .

As the hydrocarbon-containing surfactant, sodium dodecyl sulfate (SDS) is preferable. The sodium dodecyl sulfate may be obtained from coconut oil or palm kernel oil raw material. Further, it mainly contains sodium dodecyl sulfate, but may contain a small amount of other R ^g -L ^g -M ^g surfactants having different R ^g groups.

The hydrocarbon-containing surfactants include highly branched C10 tertiary carboxylic acids supplied by Resolution Performance Products as Versatic (registered trademark) 10, and straight chain supplied by BASF as Avane (registered trademark) S series. A chain alkyl polyether sodium sulfonate can also be used.

A siloxane surfactant can also be used as the hydrocarbon-containing surfactant. Examples of the siloxane surfactant include Lubrizol Advanced Materials, Inc. Examples include SilSense ^™ PE-100 silicone, SilSense ^™ CA-1 silicone available from Noveon Consumer Specialties, Inc.

Examples of the hydrocarbon-containing surfactant include sulfosuccinate surfactant Lankropol® K8300 available from Akzo Nobel Surface Chemistry LLC, diisodecyl sulfosuccinate available as Emulsogen® SB10 from Clariant, and Na salt. Also, diisotridecyl sulfosuccinate, Na salt, etc., available from Cesapinia Chemicals as Polyol® TR / LNA.

The hydrocarbon-containing surfactant can be inactivated by reacting the hydrocarbon-containing surfactant with an oxidant. That is, the surfactant (F) is preferably obtained by reacting the hydrocarbon-containing surfactant with the oxidizing agent. By inactivating, the telogenicity of the hydrocarbon-containing surfactant is reduced, and advantages such as shortening the polymerization time can be obtained.

As the oxidizing agent, hydrogen peroxide or a polymerization initiator is preferable. As the polymerization initiator, those described later can be used.

The above reaction is preferably performed in an aqueous medium. When the oxidizing agent is hydrogen peroxide, the reaction temperature is preferably 50 ° C. or lower, and more preferably 10 ° C. or higher. The temperature of the reaction when the oxidizing agent is the polymerization initiator may be the same temperature as the polymerization, for example, 0 to 100 ° C. The reaction time is usually 30 minutes or longer.

The weight ratio of the oxidizing agent to the hydrocarbon-containing surfactant is preferably 0.15: 1 to 3.5: 1, more preferably 0.3: 1 to 2.6: 1, and still more preferably 0. .5: 1 to 1.6: 1.

The above reaction is preferably performed in the presence of an inactivation aid.
The deactivation assistant is preferably a metal in the form of a metal ion, more preferably a transition metal ion, and at least one selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, Ce and Ag. More preferred are ions of the metal species, particularly preferred are ions of at least one metal selected from the group consisting of Fe and Cu, and most preferred are ferrous ions or cuprous ions. Metal ions are generated by introducing sulfate, sulfite, metal chloride, and the like into an aqueous medium.
The weight ratio of the oxidizing agent to the deactivation assistant is preferably 20: 1 to 400: 1, more preferably 30: 1 to 300: 1, and still more preferably 60: 1 to 200: 1.

As the reaction procedure, the procedure described in JP 2013-542308 A can be adopted.

When the reaction is carried out in an aqueous medium, an aqueous solution containing a deactivated hydrocarbon-containing surfactant is obtained. By adding the resulting aqueous solution to the polymerization vessel, the deactivated surfactant can be used for the polymerization. That is, the production method of the present invention can include a step of inactivating the hydrocarbon-containing surfactant, and this step is preferably performed before the step of polymerizing. When a polymerization initiator is used as the oxidizing agent, the obtained aqueous solution can also be used for initiating polymerization.

The amount of the surfactant (F) used is preferably 3000 ppm or more, more preferably 3500 ppm or more, still more preferably 4000 ppm or more, and preferably 2% by mass or less, based on the mass of the obtained fluoropolymer. Is more preferable, and 5500 ppm or less is still more preferable.

The production method of the present invention includes a step of polymerizing tetrafluoroethylene and vinylidene fluoride.

In the above polymerization, other fluoromonomer may be polymerized together with tetrafluoroethylene and vinylidene fluoride. The other fluoromonomer may be at least one ethylenically unsaturated monomer selected from the group consisting of ethylenically unsaturated monomers represented by formula (1) and formula (2).
Formula (1): CX ¹¹ X ¹² = CX ¹³ (CX ¹⁴ X ¹⁵ ) _n11 X ¹⁶
(In the formula, X ^{11 to} X ¹⁶ are the same or different and represent H, F or Cl, and n ¹¹ represents an integer of 0 to 8, except for tetrafluoroethylene and vinylidene fluoride.)

Equation ^{(2): CX 21 X 22} = CX 23 -O (CX 24 X 25) n21 X 26
(Wherein X ^{21 to} X ²⁶ are the same or different and represent H, F or Cl, and n ²¹ represents an integer of 0 to 8)

Examples of the ethylenically unsaturated monomer represented by the formula (1) include CF ₂ = CFCl, CF ₂ = CFCF ₃ , and the following formula (3):
_{CH 2 = CF- (CF 2)} n11 X 16 (3)
(Wherein X ¹⁶ and n ¹¹ are the same as above), and the following formula (4):
_{CH 2 = CH- (CF 2)} n11 X 16 (4)
(Wherein X ¹⁶ and n ¹¹ are the same as above)
It is preferably at least one selected from the group consisting of: CF ₂ = CFCl, CH ₂ = CFCF ₃ , CH ₂ = CH-C ₄ F ₉ , CH ₂ = CH-C ₆ F ₁₃ , CH ₂ = More preferably, it is at least one selected from the group consisting of CF-C ₃ F ₆ H and CF ₂ = CFCF _3, and at least one selected from CF ₂ = CFCl and CH ₂ = CFCF ₃ Is more preferable.

The ethylenically unsaturated monomer represented by the formula (2) includes a group consisting of CF ₂ = CF-OCF ₃ , CF ₂ = CF-OCF ₂ CF ₃ and CF ₂ = CF-OCF ₂ CF ₂ CF _3. It is preferable that it is at least one selected from more.

The polymerization of the vinylidene fluoride is preferably emulsion polymerization in terms of high productivity and low environmental burden.

The above polymerization can be carried out in the presence of a polymerization initiator. As said polymerization initiator, an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator can be used, and it is preferable to use a water-soluble radical polymerization initiator.

The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, for example, dialkyl such as diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, disec-butyl peroxydicarbonate, etc. Peroxyesters such as peroxycarbonates, t-butylperoxyisobutyrate and t-butylperoxypivalate, and dialkyl peroxides such as di-t-butylperoxide are also used as di (ω-hydro -Dodecafluoroheptanoyl) peroxide, di (ω-hydro-tetradecafluoroheptanoyl) peroxide, di (ω-hydro-hexadecafluorononanoyl) peroxide, di (perfluorobutyryl) peroxide, di (Perful Valeryl) Par Xide, Di (perfluorohexanoyl) peroxide, Di (perfluoroheptanoyl) peroxide, Di (perfluorooctanoyl) peroxide, Di (perfluorononanoyl) peroxide, Di (ω-chloro-hexafluoro Butyryl) peroxide, di (ω-chloro-decafluorohexanoyl) peroxide, di (ω-chloro-tetradecafluorooctanoyl) peroxide, ω-hydro-dodecafluoroheptanoyl-ω-hydrohexadecafluoro Nonanoyl-peroxide, ω-chloro-hexafluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydrododecafluoroheptanoyl-perfluorobutyryl-peroxide, di (dichloropentafluorobutanoy ) Peroxide, di (trichlorooctafluorohexanoyl) peroxide, di (tetrachloroundecafluorooctanoyl) peroxide, di (pentachlorotetradecafluorodecanoyl) peroxide, di (undecachlorodotriacontafluoro) Typical examples include docosanoyl) peroxide di [perfluoro (or fluorochloro) acyl] peroxides.

The water-soluble radical polymerization initiator may be a known water-soluble peroxide, for example, ammonium salts such as persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, percarbonate, potassium salts, sodium salts. , T-butyl permalate, t-butyl hydroperoxide and the like. A reducing agent such as sulfites and sulfites may be used in combination with the peroxide, and the amount used may be 0.1 to 20 times the peroxide.

Among these, a persulfate is more preferable as the polymerization initiator.

The above polymerization is carried out in the presence of an aqueous medium. As the aqueous medium, water is preferable. The water used for the polymerization is preferably ion-exchanged water, and the electrical conductivity is preferably 10 μS / cm or less and lower. If the ion content is large, the reaction rate may not be stable. Even in a fluorinated solvent, it is preferable to have a high purity with few components such as an acid and a compound containing a chlorine group contained in the production process. A compound containing an acid content, chlorine, or the like may have chain transfer properties, which is preferable in stabilizing the polymerization rate and molecular weight. Furthermore, it is also preferable to use a high-purity product with few chain transfer components in the other raw materials (monomers such as vinylidene fluoride and tetrafluoroethylene, initiators, chain transfer agents, etc.) used in the polymerization. In the preparatory stage of the reaction, after water is charged, an air tightness test is performed while stirring the tank, and then the inside of the tank is repeatedly depressurized, slightly pressurized with nitrogen, and depressurized, so that the oxygen concentration in the tank can be 1000 ppm or less. It is preferable to stabilize the reaction rate and adjust the molecular weight by confirming that the oxygen concentration has been reduced to a low level and then reducing the pressure again to charge the raw materials such as monomers and starting the reaction.

In the above polymerization, a chain transfer agent can be used. Examples of the chain transfer agent include hydrocarbons such as ethane, isopentane, n-hexane and cyclohexane; aromatics such as toluene and xylene; ketones such as acetone; acetates such as ethyl acetate and butyl acetate; Examples include alcohols such as methanol and ethanol; mercaptans such as methyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride, chloroform, methylene chloride, and methyl chloride. The amount added may vary depending on the size of the chain transfer constant of the compound used, but is used in the range of 0.01 to 20% by mass relative to the aqueous medium.

The residual monomer may be polymerized at the stage of recovering the residual monomer after completion of the reaction to generate a low molecular weight product. Generation | occurrence | production of a low molecular weight body becomes a factor which worsens the generation | occurrence | production of the smoke at the time of shaping | molding, the generation | occurrence | production of eyes | gear, and the heat resistance of a molded article. As a suppression method, it is desirable to reduce the recovery temperature as much as possible for the purpose of reducing the activity of the remaining initiator. Alternatively, it is effective to add hydroquinone or cyclohexane in order to stop the reaction of the remaining monomer.

It does not specifically limit as polymerization temperature, It may be 0-100 degreeC. The polymerization pressure is appropriately determined according to other polymerization conditions such as the polymerization temperature, but may usually be 0 to 9.8 MPaG.

The fluoropolymer obtained by the production method of the present invention preferably contains a tetrafluoroethylene unit, and the tetrafluoroethylene unit is preferably more than 50 mol% of all monomer units constituting the fluoropolymer, and is 95.0 mol% or less. Are preferred.

In the fluoropolymer, the tetrafluoroethylene unit is more than 50.0 mol% and not more than 95.0 mol% of all monomer units constituting the fluoropolymer, and the vinylidene fluoride unit is composed of all monomer units constituting the fluoropolymer. It is preferable that it is 5.0 mol% or more and less than 50.0 mol%.

The fluoropolymer is
55.0-90.0 mol% tetrafluoroethylene,
5.0-44.9 mol% vinylidene fluoride, and
0.1 to 10.0 mol% of an ethylenically unsaturated monomer represented by the formula (1),
It is preferable that it is a copolymer containing these copolymer units.

More preferably,
55.0-85.0 mol% tetrafluoroethylene,
10.0-44.9 mol% vinylidene fluoride, and
0.1 to 5.0 mol% of an ethylenically unsaturated monomer represented by the formula (1),
It is a copolymer containing the copolymerization unit.

More preferably,
55.0-85.0 mol% tetrafluoroethylene,
13.0-44.9 mol% vinylidene fluoride, and
0.1 to 2.0 mol% of an ethylenically unsaturated monomer represented by the formula (1),
It is a copolymer containing the copolymerization unit.

In addition to improving the mechanical strength of the fluoropolymer at high temperature, the low permeability of the fluoropolymer is particularly excellent, so that the ethylenically unsaturated monomer represented by the formula (1) is CH ₂ = _{CH-C 4} F _9, it is preferable that _{CH 2 = CH-C 6 F} 13 and _CH 2 = _CF-C 3 at least one monomer selected from the group consisting of _{F 6} H. More preferably, the ethylenically unsaturated monomer represented by the formula (1) is CH ₂ ═CH—C ₄ F ₉ , CH ₂ ═CH—C ₆ F ₁₃ and CH ₂ ═CF—C ₃ F ₆ H. And at least one monomer selected from the group consisting of:
55.0-80.0 mol% tetrafluoroethylene,
19.5-44.9 mol% vinylidene fluoride, and
0.1 to 0.6 mol% of an ethylenically unsaturated monomer represented by the formula (1),
It is a copolymer containing the copolymer unit of this.

The fluoropolymer is
58.0-85.0 mol% tetrafluoroethylene,
10.0-41.9 mol% vinylidene fluoride, and
0.1 to 5.0 mol% of an ethylenically unsaturated monomer represented by the formula (1),
A copolymer containing the copolymer unit may be used.

The fluoropolymer is
55.0-90.0 mol% tetrafluoroethylene,
9.2-44.2 mol% vinylidene fluoride, and
0.1 to 0.8 mol% of an ethylenically unsaturated monomer represented by the formula (2),
It is also preferable that it is a copolymer containing these copolymer units.

More preferably,
58.0-85.0 mol% tetrafluoroethylene,
14.5 to 39.9 mol% vinylidene fluoride, and
0.1 to 0.5 mol% of an ethylenically unsaturated monomer represented by the formula (2),
It is a copolymer containing the copolymerization unit.

The fluoropolymer is
55.0-90.0 mol% tetrafluoroethylene,
5.0-44.8 mol% vinylidene fluoride,
0.1 to 10.0 mol% of an ethylenically unsaturated monomer represented by the formula (1), and
0.1 to 0.8 mol% of an ethylenically unsaturated monomer represented by the formula (2),
It is also preferable that it is a copolymer containing these copolymer units.

More preferably,
55.0-85.0 mol% tetrafluoroethylene,
9.5-44.8 mol% vinylidene fluoride,
0.1 to 5.0 mol% of an ethylenically unsaturated monomer represented by the formula (1), and
0.1 to 0.5 mol% of an ethylenically unsaturated monomer represented by the formula (2),
It is a copolymer containing the copolymerization unit.

More preferably,
55.0-80.0 mol% tetrafluoroethylene,
19.8-44.8 mol% vinylidene fluoride,
0.1 to 2.0 mol% of an ethylenically unsaturated monomer represented by the formula (1), and
0.1 to 0.3 mol% of an ethylenically unsaturated monomer represented by the formula (2),
It is a copolymer containing the copolymerization unit. When the fluoropolymer has this composition, it is particularly excellent in low permeability.

The fluoropolymer is
58.0-85.0 mol% tetrafluoroethylene,
9.5-39.8 mol% vinylidene fluoride,
0.1 to 5.0 mol% of an ethylenically unsaturated monomer represented by the formula (1), and
0.1 to 0.5 mol% of an ethylenically unsaturated monomer represented by the formula (2),
A copolymer containing the copolymer unit may be used.

When the content of each monomer is within the above range, the fluoropolymer has higher crystallinity and 170 ° C. than a conventionally known copolymer comprising tetrafluoroethylene, vinylidene fluoride and a third component. However, since the storage elastic modulus is high, it is excellent in mechanical strength, chemical resistance and low permeability at high temperatures. The low permeability at a high temperature is, for example, low permeability to methane, hydrogen sulfide, CO ₂ , methanol, hydrochloric acid and the like.

The content of each monomer in the copolymer can be calculated by appropriately combining NMR and elemental analysis depending on the type of monomer.

The fluoropolymer preferably has a melt flow rate (MFR) of 0.1 to 50 g / 10 min.

The above MFR is based on ASTM D3307-01 and uses a melt indexer (manufactured by Toyo Seiki Co., Ltd.) at 297 ° C. under a load of 5 kg and the mass of the polymer flowing out from a nozzle having an inner diameter of 2 mm and a length of 8 mm per 10 minutes. (G / 10 minutes).

The fluoropolymer preferably has a melting point of 180 ° C. or higher, and the upper limit may be 290 ° C. A more preferred lower limit is 200 ° C and an upper limit is 270 ° C.

The melting point is measured by using a differential scanning calorimeter RDC220 (manufactured by Seiko Instruments) according to ASTM D-4591 at a heating rate of 10 ° C./min, and the temperature corresponding to the peak of the endothermic curve obtained is measured. The melting point.

The fluoropolymer preferably has a thermal decomposition starting temperature (1% mass loss temperature) of 360 ° C. or higher. A more preferred lower limit is 370 ° C., and a more preferred lower limit is 380 ° C. If the said thermal decomposition start temperature is in the said range, an upper limit can be 410 degreeC, for example.

The thermal decomposition start temperature is a temperature at which 1% by mass of the fluoropolymer subjected to the heating test is decomposed, and the thermal decomposition starting temperature of the fluoropolymer subjected to the heating test using a differential thermal / thermogravimetric measuring device [TG-DTA] is used. It is a value obtained by measuring the temperature when the mass is reduced by 1% by mass.

The fluoropolymer preferably has a storage elastic modulus (E ′) at 170 ° C. of 60 to 400 MPa as measured by dynamic viscoelasticity. If the storage elastic modulus at a high temperature is too low, the mechanical strength is rapidly reduced and deformation is likely to occur. If it is too high, the resin may be too hard and molding may be difficult.

The storage elastic modulus is a value measured at 170 ° C. by dynamic viscoelasticity measurement. More specifically, the storage elastic modulus is a dynamic viscoelastic device DVA220 manufactured by IT-Measurement Control Co., Ltd., having a length of 30 mm, a width of 5 mm, a thickness of 0. This is a value obtained by measuring a 25 mm sample under the conditions of a tensile mode, a grip width of 20 mm, a measurement temperature of 25 ° C. to 250 ° C., a temperature increase rate of 2 ° C./min, and a frequency of 1 Hz. A preferable storage elastic modulus (E ′) at 170 ° C. is 80 to 350 MPa, and a more preferable storage elastic modulus (E ′) is 100 to 350 MPa.
For the measurement sample, for example, the molding temperature is set to 50 to 100 ° C. higher than the melting point of the fluoropolymer, and a film molded to a thickness of 0.25 mm at a pressure of 3 MPa is cut to a length of 30 mm and a width of 5 mm. Can be created.

The fluoropolymer obtained by the above-described production method may be in any form, and may be an aqueous dispersion, powder, pellet or the like.

The fluoropolymer can be molded into various molded products, and the molded products obtained are excellent in mechanical strength and chemical resistance at high temperatures, low permeability at high temperatures, and the like. The molded body is not colored and has a good appearance.

It does not specifically limit as a shape of the said molded object, For example, a hose, a pipe, a tube, a sheet | seat, a seal, a gasket, packing, a film, a tank, a roller, a bottle, a container etc. may be sufficient.

The shaping | molding method for obtaining the said molded object is not specifically limited, For example, compression molding, extrusion molding, transfer molding, injection molding, lottery molding, lotining molding, electrostatic coating etc. are mentioned.

Fillers, plasticizers, processing aids, mold release agents, pigments, flame retardants, lubricants, light stabilizers, weathering stabilizers, conductive agents, antistatic agents, UV absorbers, antioxidants, foams to the above fluoropolymers After mixing the agent, fragrance, oil, softening agent, dehydrofluorinating agent, etc., it may be molded. Examples of the filler include polytetrafluoroethylene, mica, silica, talc, celite, clay, titanium oxide, and barium sulfate. Examples of the conductive agent include carbon black. Examples of the plasticizer include dioctyl phthalic acid and pentaerythritol. Examples of processing aids include carnauba wax, sulfone compounds, low molecular weight polyethylene, and fluorine-based aids. Examples of the dehydrofluorinating agent include organic oniums and amidines.

The said fluoropolymer can be used conveniently for the riser pipe | tube which conveys a material from the seabed on the sea surface in a seabed oil field or gas field. Further, it can be suitably used as a coating material or lining material for the innermost surface and outermost surface of a fluid transfer metal pipe for crude oil or natural gas, regardless of whether it is underground, on the ground, or on the seabed. The purpose of coating and lining the innermost surface is that crude oil and natural gas contain carbon dioxide and hydrogen sulfide, which cause corrosion of metal pipes. This is to reduce the fluid friction of crude oil of viscosity. The outermost surface is also for suppressing corrosion caused by seawater or acidic water. When lining and coating the innermost and outermost surfaces, glass fiber, carbon fiber, aramid resin, mica, silica, talc, celite, clay, titanium oxide, etc. are used to further improve the rigidity and strength of the fluoropolymer. It may be filled. Moreover, in order to make it adhere | attach with a metal, you may perform the process which uses an adhesive agent or roughens the metal surface.
Furthermore, it can be suitably used as a molding material for the following molded articles.

As the molded body, for example,
Fluid transport members for food production equipment such as food packaging films, lining materials for fluid transfer lines used in food manufacturing processes, packing, sealing materials, sheets;
Chemical liquid transfer members such as medicine stoppers, packaging films, lining materials for fluid transfer lines used in chemical manufacturing processes, packing, seal materials, sheets;
Internal lining material for chemical tanks and piping in chemical plants and semiconductor factories;
Fuel transfer members such as O (square) rings, tubes, packings, valve cores, hoses, seals, etc. used in automobile fuel systems and peripheral devices, hoses, seals, etc. used in automobile AT devices;
Car parts such as carburetor flange gaskets, shaft seals, valve stem seals, sealing materials, hoses, etc. used in automobile engines and peripheral devices, and other automobile parts such as automobile brake hoses, air conditioner hoses, radiator hoses, and wire covering materials;
Chemical solution transfer members for semiconductor devices such as O (square) rings, tubes, packings, valve cores, hoses, sealing materials, rolls, gaskets, diaphragms, joints, etc. of semiconductor manufacturing equipment;
Paint and ink components such as paint rolls, hoses, tubes, and ink containers for painting equipment;
Tubes for food and drink or tubes for food and drink, hoses, belts, packings, food and drink transfer members such as joints, food packaging materials, glass cooking equipment;
Waste liquid transport components such as waste liquid transport tubes and hoses;
High temperature liquid transport members such as tubes and hoses for high temperature liquid transport;
Steam piping members such as tubes and hoses for steam piping;
Anticorrosion tape for piping such as tape wrapped around piping of ship decks;
Various coating materials such as an electric wire coating material, an optical fiber coating material, a transparent surface coating material and a back surface agent provided on the light incident side surface of the photovoltaic element of the solar cell;
Sliding members such as diaphragm pump diaphragms and various packings;
Agricultural film, weatherproof covers such as various roof materials and side walls;
Interior materials used in the construction field, glass covering materials such as non-flammable fire safety glass;
Lining materials such as laminated steel sheets used in the field of home appliances;
Etc.

Examples of the fuel transfer member used in the fuel system of the automobile further include a fuel hose, a filler hose, and an evaporation hose. The fuel transfer member can also be used as a fuel transfer member for fuel containing gasoline additives such as for sour gasoline resistant, alcohol resistant fuel, methyl tertiary butyl ether / amine resistant, etc.

The above-mentioned drug stopper / packaging film has excellent chemical resistance against acids and the like. Moreover, the said chemical | medical solution transfer member can also mention the anticorrosion tape wound around chemical plant piping.

Examples of the molded body include a radiator tank, a chemical tank, a bellows, a spacer, a roller, a gasoline tank, a waste liquid transport container, a high temperature liquid transport container, and a fishery / fish farm tank.

As the above molded products, there are also automobile bumpers, door trims, instrument panels, food processing equipment, cooking equipment, water and oil repellent glass, lighting related equipment, display boards / housings for office automation equipment, electric signs, displays, liquid crystals Examples include members used for displays, mobile phones, printed boards, electrical / electronic components, sundries, trash cans, bathtubs, unit baths, ventilation fans, lighting frames, and the like.

The fluoropolymer can also be suitably used as a powder coating. The powder coating material may have an average particle size of 10 to 1000 μm. The average particle size can be measured using a laser diffraction particle size distribution analyzer. A coating film without coloring can be obtained by spraying the powder coating material on the substrate by electrostatic coating and then baking.

Next, the present invention will be described with reference to examples, but the present invention is not limited to such examples.

Example 1
In a 2 L stainless steel autoclave equipped with a stirrer, 0.3 g of deionized water 1000 g and CH ₂ ═CFCF ₂ —O— (CF (CF ₃ ) CF ₂ O) —CF (CF ₃ ) —COONH ₄ And 2 g of F (CF ₂ ) ₅ COONH ₄ were sealed. After the inside of the autoclave was replaced with vacuum and nitrogen, 3.5 g of vinylidene fluoride (VdF) and 16.5 g of tetrafluoroethylene (TFE) were added and the temperature was raised to 80 ° C. The reaction was started by adding 0.5 g of ethyl acetate and 0.2 g of ammonium persulfate. A mixed gas of TFE / VdF = 72/28 molar ratio was supplied so as to maintain the internal pressure of the tank, and 170 g of mixed gas was added by the end of the reaction. After adding a predetermined amount of the mixed gas, the gas in the tank was released.
The inside of the tank was cooled, and 0.2 g of 28 wt% aluminum sulfate aqueous solution was added to the obtained dispersion. The slurry was filtered and dried to obtain 165 g of polymer. The composition of the obtained polymer was TFE / VdF = 71.2 / 28.8 (mol%).

Example 2
In a 2 L stainless steel autoclave equipped with a stirrer, 0.3 g of deionized water 1000 g and CH ₂ ═CFCF ₂ —O— (CF (CF ₃ ) CF ₂ O) —CF (CF ₃ ) —COONH ₄ And 2 g of F (CF ₂ ) ₅ COONH ₄ were sealed. After the inside of the autoclave was replaced with vacuum and nitrogen, 1 g of perfluoro (propyl) vinyl ether, 7.6 g of vinylidene fluoride (VdF), and 14.4 g of tetrafluoroethylene (TFE) were added and the temperature was raised to 80 ° C. The reaction was started by adding 0.2 g of ethyl acetate and 0.2 g of ammonium persulfate. A mixed gas of TFE / VdF = 55/45 molar ratio was supplied so as to maintain the internal pressure of the tank, and perfluoro (propyl) vinyl ether was simultaneously charged to 0.9 part with respect to 100 parts of the added mixed gas. . By the end of the reaction, 170 g of mixed gas was added, and the gas in the tank was released.
After cooling the inside of the tank, 0.2 g of 28 wt% aluminum sulfate aqueous solution was added to the obtained dispersion, and the slurry was filtered and dried to obtain 164 g of polymer. The composition of the obtained polymer was TFE / VdF / perfluoro (propyl) vinyl ether = 55.2 / 44.6 / 0.2 (mol%).

Example 3
In a 2 L stainless steel autoclave equipped with a stirrer, 1070 g of deionized water and 0.214 g of CH ₂ ═CFCF ₂ —O— (CF (CF ₃ ) CF ₂ O) —CF (CF ₃ ) —COONH ₄ 3.2 g of F (CF ₂ ) ₅ COONH ₄ and sealed. After the inside of the autoclave was replaced with vacuum and nitrogen, 6.6 g of vinylidene fluoride (VdF) and 15.4 g of tetrafluoroethylene (TFE) were added and the temperature was raised to 80 ° C. CH ₂ ═CH (CF ₂ ) ₅ CF ₃ (0.3 g), ethyl acetate (0.5 g), and ammonium persulfate (0.214 g) were added to initiate the reaction. A mixed gas of TFE / VdF = 60/40 molar ratio was supplied so as to maintain the internal pressure of the tank, and 268 g of mixed gas was added by the end of the reaction. Further, CH ₂ ═CH (CF ₂ ) ₅ CF ₃ was continuously added in accordance with the supply of the mixed gas, and 3.24 g was added until the end of the reaction. Further, 0.107 g of ammonium persulfate was added every 1.5 hours. After 6.3 hours from the start of polymerization, the gas in the tank was released to complete the reaction.
After cooling the inside of the tank, 0.2 g of 28 wt% aluminum sulfate aqueous solution was added to the obtained dispersion, and the slurry was filtered and dried to obtain 260 g of polymer.
The composition of the obtained polymer was TFE / VdF / CH ₂ ═CH (CF ₂ ) ₅ CF ₃ = 60.3 / 39.5 / 0.2 (mol%).

Example 4
In a 2 L stainless steel autoclave equipped with a stirrer, 0.3 g of deionized water 1000 g and CH ₂ ═CFCF ₂ —O— (CF (CF ₃ ) CF ₂ O) —CF (CF ₃ ) —COONH ₄ And 2 g of F (CF ₂ ) ₅ COONH ₄ were sealed. After the inside of the autoclave was replaced with vacuum and nitrogen, 7.6 g of vinylidene fluoride (VdF) and 14.4 g of tetrafluoroethylene (TFE) were added and the temperature was raised to 80 ° C. The reaction was started by adding 0.5 g of ethyl acetate and 0.2 g of ammonium persulfate. A mixed gas of TFE / VdF = 55/45 molar ratio was supplied so as to maintain the internal pressure of the tank, and 150 g of mixed gas was added until the end of the reaction. After adding a predetermined amount of the mixed gas, the gas in the tank was released.
After cooling the inside of the tank, 0.2 g of 28 wt% aluminum sulfate aqueous solution was added to the obtained dispersion, and the slurry was filtered and dried to obtain 138 g of polymer. The composition of the obtained polymer was TFE / VdF = 53.8 / 46.2 (mol%).

Claims (3)

A method for producing a fluoropolymer comprising a step of polymerizing tetrafluoroethylene and vinylidene fluoride in the presence of a surfactant and an aqueous medium, wherein the surfactant comprises the following groups (A) to (F): A production method characterized in that the production method is at least one selected from the group consisting of
Surfactant (A)
_{Formula: CX 2 = CFCF 2 -O- (} CF (CF 3) CF 2 O) n -CF (CF 3) -Y
(In the formula, each X is the same or different and represents F or H. n represents 0 or an integer of 1 to 10, Y represents —SO ₃ M or —COOM, and M represents H, NH ₄ or an alkali metal)) and a fluorine-containing anionic surfactant having 7 or less carbon atoms (excluding the fluorine-containing allyl ether compound)
Surfactant (B)
A group consisting of linear 1-alkanesulfonic acid having 7 to 20 carbon atoms, linear 2-alkanesulfonic acid having 7 to 20 carbon atoms, linear 1,2-alkanedisulfonic acid having 7 to 20 carbon atoms, and salts thereof. At least one alkanesulfonic acid or salt surfactant (C) selected from
At least one non-fluorinated surfactant surfactant (D) selected from the group consisting of polyvinylphosphonic acid, polyacrylic acid, polyvinyl sulfonic acid and salts thereof
Surfactant surfactant having at least one repeating unit selected from the group consisting of —CH ₂ CH ₂ O— and —CH ₂ CH ₂ CH ₂ O—, and having 2 to 100 repeating units ( E)
At least one surfactant selected from the group consisting of non-fluorinated surfactants and fluorinated surfactants having a molecular weight of less than 400, and a functional fluoropoly comprising a fluoropolyoxyalkylene chain and a functional group Ether surfactant (F)
Deactivated hydrocarbon-containing surfactant Furthermore, the manufacturing method of Claim 1 which superpose | polymerizes at least 1 sort (s) of ethylenically unsaturated monomer selected from the group which consists of an ethylenically unsaturated monomer represented by Formula (1) and Formula (2).
Formula (1): CX ¹¹ X ¹² = CX ¹³ (CX ¹⁴ X ¹⁵ ) _n11 X ¹⁶
(In the formula, X ^{11 to} X ¹⁶ are the same or different and represent H, F or Cl, and n ¹¹ represents an integer of 0 to 8, except for tetrafluoroethylene and vinylidene fluoride.)
Equation ^{(2): CX 21 X 22} = CX 23 -O (CX 24 X 25) n21 X 26
(Wherein X ^{21 to} X ²⁶ are the same or different and represent H, F or Cl, and n ²¹ represents an integer of 0 to 8) The production method according to claim 1 or 2, wherein the fluoropolymer contains more than 50 mol% of tetrafluoroethylene units of all monomer units constituting the fluoropolymer.