JP2526641B2 - Novel fluorinated cyclic polymer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel fluorine-containing cyclic polymer, more specifically, a thermoplastic resin-like fluorine-containing cyclic polymer having a specific asymmetric ring structure in its main chain. Regarding coalescence.

[Prior Art] A great deal of research has been conducted from a long time ago regarding a cyclopolymerization method of a hydrocarbon-based monomer, and a large number of hydrocarbon-based cyclic polymers are generally used, from a three-membered ring to a macrocyclic polyether. Known to be.

On the other hand, various fluoropolymers are known, and many of them have been industrially put to practical use including polytetrafluoroethylene.

However, most of them are polymers having a linear main chain based on a vinyl monomer such as a fluoroolefin or a (meth) acrylate having a fluoroalkyl group in a side chain.

There are few examples of polymers obtained by cyclopolymerization of a fluorine-based monomer, and a slight amount of the general formula CF ₂ = CF (CF ₂ ) _x CF = CF ₂ (where x is 1 to 5) is generated by γ-rays. It is known to undergo chemical polymerization. (L.
A.Waal, Fluoropolymer, Wiley-Science, 4, High Pressur
e Polymerization, P.127). Also, CF ₂ = CF-CF ₂ CFCl-
It is known that CF ₂ CF = CF ₂ polymerizes to give a transparent elastic film with excellent heat resistance and oxidation resistance (DS
Ballentine et al., USAtomic Energy Coms. B, NL−296
(T-50) 18,1954). However, none of them have sufficient transparency and flexibility because they have no ether bond in the main chain.

Further, in British Patent No. 1106344 and US Patent No. 3418302, perfluorodimethylene bis (perfluorovinyl ether) is used as a starting material to polymerize in a dilute solution,
On the main chain And / or The fluorine-containing cyclic polymer having a ring structure containing an ether bond represented by However, the ring structure of the main chain of this polymer is symmetric and therefore difficult to synthesize. In addition, there is a possibility that the solubility and the transparency are poor.

[Problems to be Solved by the Invention] An object of the present invention is to provide a novel fluorine-containing thermoplastic resin-like polymer having an asymmetric ring structure containing an ether bond in the main chain, which has heretofore been unknown. It is what

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and has the general formula And / or (However, n is 1 or 2) consisting essentially of the group (a) of repeating units of the ring structure represented by the formula (1) and having a molecular weight such that the intrinsic viscosity is at least 0.1. And the general formula And / or (Where, n is 1 or 2) repeating units a group of the ring structure represented by (a) and the general formula CF ₂ -CFX (wherein, X is _{F, Cl, O-CF 2} CF 2 CF 3, O- CF ₂ CF (CF ₃ ) OCF
₂ CF ₂ SO ₂ F, O-CF ₂ CF ₂ CF ₂ COOCH ₃ )) and essentially consists of a group (b) of repeating units
Comprising at least 80% by weight of repeating unit group (a),
The present invention newly provides a fluorine-containing thermoplastic resin-like polymer having a molecular weight such that the intrinsic viscosity is at least 0.1.

The group (a) of repeating units of the present invention is a partially fluorinated vinyl ether such as CF ₂ ═CF—O—CF ₂ —CF.
Although ₂ -CH = CH ₂ can be obtained by fluorination after obtained by cyclic polymerization, preferably the general formula _{CF 2 = CF-O (CF} 2) n CF = CF 2 ( where, n is 1 or 2 ) Perfluoroallyl vinyl ether represented by
VE) or perfluorobutenyl vinyl ether (hereinafter abbreviated as PBVE) by radical cyclopolymerization. More specifically, radical polymerization of PAVE gives n = 1 of the repeating unit group (a).
Then, n = 2 is obtained.

This finding is very surprising. Because, perfluorodiolefins known until now generally give cross-linked polymers, and perfluorodimethylene bis (perfluorovinyl ether) such as the above-mentioned British Patent No. 1106344 and U.S. Pat. It gives a soluble polymer having a ring structure in the main chain only when polymerized in a dilute solution.

 PAVE is described in Japanese Examined Patent Publication No. 60-45619.

PAVE is synthesized such as by dechlorination by zinc _{CF 2 = CF-O-CF} 2 -CF 2 -CCIF-CCIF 2.

Even more surprisingly, PAVE and PBVE can be copolymerized in any proportion, thus providing a copolymer having n = 1 and n = 2 repeating units in any proportion.

The polymer composed of the group (a) of these repeating units is a transparent resin and is soluble in a fluorine-based solvent such as perfluoro (2-butyltetrahydrofuran). Also, from the infrared absorption spectrum, no absorption around 1790 cm ^-1 based on the double bond is observed.

As the ring structure, a 5-membered ring or 6-membered ring structure with less strain is preferentially obtained.

Further, perfluorovinyl ether represented by the general formula CF ₂ = CF-O (CF ₂ ) _n CF = CF ₂ (where n is 1 or 2) is represented by the general formula CF ₂ = CFX (where X is F, Cl. , O−CF ₂ CF ₂ CF ₃ , O−CF ₂ CF (CF ₃ ) OCF
₂ CF ₂ SO ₂ F, O-CF ₂ CF ₂ CF ₂ COOCH ₃ ) radical copolymerized with a comonomer represented by the general formula And / or (Where, n is 1 or 2) repeating units a group of the ring structure represented by (a) and the general formula CF ₂ -CFX (wherein, X is _{F, Cl, O-CF 2} CF 2 CF 3, O- CF ₂ CF (CF ₃ ) OCF
₂ CF ₂ SO ₂ F, O—CF ₂ CF ₂ CF ₂ COOCH ₃ ) and a copolymer consisting essentially of the group (b) of repeating units.

General formula CF ₂ = CFX (where X is F, Cl, O−CF ₂ CF ₂ CF ₃ , O−CF ₂ CF (CF ₃ ) OCF
₂ CF ₂ SO ₂ F, O-CF ₂ CF ₂ CF ₂ COOCH ₃ ) are known.

In order to obtain a transparent and solvent-soluble polymer, it is preferable that the repeating unit group (a) is contained in an amount of 80% by weight or more.
If the content of the repeating unit group (a) is less than this range, the transparency, solvent solubility, strength, etc. of the resin will be impaired.

Further, the molecular weight is preferably 0.1 or more in terms of intrinsic viscosity. If the intrinsic viscosity is lower than 0.1, the resin strength will be low and not practical.

Radical polymerization is used as a method for polymerizing these polymers. That is, the polymerization method is not particularly limited as long as it can radically proceed, and examples thereof include organic and inorganic radical initiators, polymerization by light, ionizing radiation and heat. As the polymerization method, bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization can be used.

The molecular weight can be controlled by the temperature of polymerization, the concentration of the initiator and the like. A chain transfer agent may be used.

The polymerization composition of the copolymer can be controlled by the charging ratio of each comonomer.

It is possible to control the properties of the resin such as the solubility of the copolymer obtained, the glass transition point, the breaking strength, the elongation, the yield stress elastic modulus, and the adhesiveness of the substrate, depending on the type of comonomer and the polymerization ratio. Further, the polymerization rate can be controlled during the polymerization depending on the kind of the comonomer.

When tetrafluoroethylene is used as a comonomer, it is possible to lower the glass transition point and accelerate the polymerization rate. Solubility changes when chlorotrifluoroethylene is used as a comonomer. CF ₂ = CF-OC in the comonomer
The elongation is improved by using F ₂ CF ₂ CF ₃ .

CF ₂ = CF-O-CF ₂ CF (CF ₃ ) -O-CF ₂ CF in the comonomer
₂ SO ₂ F or CF ₂ = CF-O-CF ₂ CF ₂ CF ₂ COOCH ₃ improves the adhesion to a substrate.

 It is also possible to use two or more comonomers.

The polymer composed of the group of repeating units (a) and the group of (b) is a transparent resin and is soluble in a fluorine-based solvent such as perfluoro (2-butyltetrahydrofuran). In addition, based on the double bond from the infrared absorption spectrum, 1790
Absorption around cm ^-1 is not observed.

The proportion of copolymerization is determined by ¹⁹ F-NMR and elemental analysis.

It is needless to say that the above description is for helping understanding of the present invention and does not limit the present invention in any way.

[Examples] Next, examples of the present invention will be described more specifically, but it goes without saying that the present invention is not limited to these examples.

Example 1 30 g of PAVE and 0.3 g of the polymerization initiator diisopropyl peroxydicarbonate were placed in a pressure-resistant glass ampoule having an internal volume of 100 ml. After freezing and degassing twice, 25 ℃
It was polymerized for 16 hours. The pressure during the polymerization reaction was lower than atmospheric pressure. As a result, 4.5 g of a polymer was obtained.

When the infrared absorption spectrum of this polymer was measured, there was no absorption near 1790 cm ⁻¹ due to the double bond in the monomer. Further, when this polymer was dissolved in perfluorobenzene and the ¹⁹ F-NMR spectrum was measured,
A spectrum showing the following repeating structure was obtained.

The intrinsic viscosity [η] of this polymer is Fluorinert FC-75
It was found to be 0.50 at 30 ° C. in a liquid (trade name: perfluoro (2-butyltetrahydrofuran) manufactured by 3M Co., Ltd. as a main component; hereinafter, abbreviated as FC-75), indicating a high degree of polymerization.

The glass transition point of the polymer is 69 ° C., and it is a tough and transparent glassy polymer at room temperature. The 10% thermal decomposition temperature was 462 ℃, indicating high thermal stability. Further, this polymer was colorless and transparent, had a low refractive index of 1.34, and had a high light transmittance of 95%.

The permeability coefficients of this polymer for various gases were measured. The measurement results are shown below.

Example 2 10 g of PAVE, trichlorotrifluoroethane (hereinafter,
R-113) and 10 mg of the polymerization initiator diisopropyl peroxydicarbonate were placed in a pressure-resistant glass ampoule having an internal volume of 50 ml. After repeating freeze degassing twice, polymerization was carried out at 40 ° C. for 14 hours. The pressure during the polymerization reaction was lower than atmospheric pressure. As a result, 6.1 g of a polymer was obtained.

This polymer had an intrinsic viscosity [η] of 0.37 at 30 ° C. in FC-75, and was found to be a high molecular weight polymer. From the ¹⁹ F-NMR spectrum, the obtained polymer was found to be the same as that in Example 1.

Example 3 30 g of PAVE and a polymerization initiator Was placed in a pressure-resistant glass ampoule having an internal volume of 50 ml.
After freeze-deaeration was repeated twice, polymerization was carried out at 30 ° C. for 16 hours.
The pressure during polymerization was below atmospheric pressure. As a result of the polymerization, 16 g of a polymer was obtained. The intrinsic viscosity [η] of this polymer is FC-75
It was 0.505 at 30 ° C.

Synthesis Example 1 (Synthesis of CF ₂ = CFCF ₂ CF ₂ OCF = CF ₂ ) 2000 g of CF ₂ ClCFClCF ₂ COF was reacted with hexafluoropropylene oxide in the presence of cesium fluoride, and potassium salt was further added using potassium hydroxide. And then thermally decomposed to obtain CF ₂ ClCFClCF ₂ CF ₂ OCF = CF ₂ as a product. Then, this product is reacted with Zn / dioxane to remove Cl ₂ , and CF ₂ = CFCF ₂ CF ₂ OCF ₂ = CF ₂ (P
BVE) was obtained. The structure of the fluorine-containing monomer was determined to be ¹⁹ F-
Confirmed by NMR.

Example 4 5.42 g of PBVE obtained in the above Synthesis Example 1 and a polymerization initiator Was placed in a pressure-resistant glass ampoule having an internal volume of 50 ml.
After freeze-deaeration was repeated twice, polymerization was carried out at 25 ° C. for 48 hours.
The pressure during the polymerization reaction was lower than atmospheric pressure. as a result,
2.22 g of a polymer was obtained.

When the infrared absorption spectrum of this polymer was measured, there was no absorption near 1790 cm ⁻¹ due to the double bond in the monomer. Further, when this polymer was dissolved in perfluorobenzene and the ¹⁹ F-NMR spectrum was measured,
A spectrum showing the following repeating structure was obtained.

Or The intrinsic viscosity [η] of this polymer is 0.55 at 30 ° C. in FC-75.
It was found that the degree of polymerization was high.

The glass transition point of the polymer is 108 ° C., and it is a tough and transparent glassy polymer at room temperature. Moreover, the 10% thermal decomposition temperature was 457 ° C, and the thermal stability was high. Further, this polymer was colorless and transparent, had a low refractive index of 1.34, and had a high light transmittance of 95%.

Example 5 5 g of PAVE, 5 g of PBVE and a polymerization initiator Was placed in a glass reactor having an inner volume of 60 ml containing 40 g of water. Repeat freezing and degassing twice, while stirring
Polymerization was performed at 25 ° C for 24 hours. The pressure during the polymerization reaction was lower than atmospheric pressure. As a result, 5.5 g of a polymer was obtained.

When the infrared absorption spectrum of this polymer was measured, there was no absorption near 1790 cm ⁻¹ due to the double bond in the monomer. Further, this polymer was dissolved in perfluorobenzene and the ¹⁹ F-NMR spectrum was measured to confirm the structure. As a result, the obtained polymer is as well as Or It was found that it is a copolymer of the ring structural unit derived from PAVE and the ring structural unit derived from PBVE as described above, and the ring structural unit derived from PAVE was found to be 54% by weight.

The intrinsic viscosity [η] of this polymer is 0.44 at 30 ° C. in FC-75.
It was found that the degree of polymerization was high.

The glass transition point of the polymer is 91 ° C, and it is a tough and transparent glassy polymer at room temperature. Further, the 10% thermal decomposition temperature was 435 ° C., and the thermal stability was high. Further, this polymer was colorless and transparent, had a low refractive index of 1.34, and had a high light transmittance of 95%.

Example 6 5 g of PAVE, 15 g of R-113 and a polymerization initiator 80 mg of a 5 wt% R-113 solution was placed in a pressure-resistant glass ampoule having an internal volume of 100 ml. CF after three times of freeze degassing
₂ = 0.5 g of CF ₂ was charged. Polymerization was carried out at 30 ° C. for 6 hours while shaking in an incubator, and as a result, 1.5 g of solid was obtained.

The obtained solid was dissolved in perfluorobenzene to obtain ¹⁹ F-N
The structure was confirmed by MR spectrum. As a result, the obtained polymer is And a structural unit derived from PAVE and a structural unit derived from CF ₂ = CF ₂ such as CF ₂ —CF ₂ , wherein the cyclic structural unit derived from PAVE is 81% by weight. I knew it was. The intrinsic viscosity [η] of this polymer at 30 ° C in FC-75 is 0.
It was 425.

Example 7 20 g of PBVE obtained in Synthesis Example 1 and a polymerization initiator Was placed in a pressure-resistant glass ampoule having an internal volume of 200 ml. After freeze-deaeration was repeated twice, 1.0 g of CF ₂ = CFCl was charged. Polymerization was carried out at 25 ° C for 10 hours while shaking in an incubator. As a result, 4.5 g of a polymer was obtained.

When the infrared absorption spectrum of this polymer was measured, there was no absorption near 1790 cm ⁻¹ due to the double bond in the monomer. Further, this polymer was dissolved in perfluorobenzene and the ¹⁹ F-NMR spectrum was measured to confirm the structure. As a result, the obtained polymer is Or And a copolymer of CF ₂ -CFCl PBVE structural units derived from the induced ring structure units and CF ₂ = CFCl from such as, that the ring structure units derived from PBVE is 84 wt% all right. The intrinsic viscosity [η] of this polymer was 0.43 at 30 ° C. in FC-75, indicating that the polymerization degree was high.

The polymer is a tough and transparent polymer at room temperature. Also,
The 10% thermal decomposition temperature was 421 ° C, indicating high thermal stability. Further, this polymer was also dissolved in the FC-75 / R-113 mixed solvent.

Example 8 20 g of PBVE obtained in Synthesis Example 1 and a polymerization initiator Was placed in a pressure-resistant glass ampoule having an internal volume of 200 ml. After repeating freeze deaeration twice, 0.5 g of CF ₂ = CF ₂ was charged. Polymerization was carried out at 25 ° C for 5 hours while shaking in an incubator. As a result, 5.8 g of a polymer was obtained.

When the infrared absorption spectrum of this polymer was measured, there was no absorption near 1790 cm ⁻¹ due to the double bond in the monomer. Further, this polymer was dissolved in perfluorobenzene and the ¹⁹ F-NMR spectrum was measured to confirm the structure. As a result, the obtained polymer is Or And CF ₂ is a copolymer of structural units derived such a ring structure that units and CF ₂ = CF ₂ derived from PBVE as -CF _2, 94% by weight the induced cyclic structural units from PBVE I knew it was. The intrinsic viscosity [η] of this polymer was 0.53 at 30 ° C. in FC-75, indicating a high degree of polymerization.

 The polymer is a tough, transparent polymer at room temperature.

Example 9 PAVE of _{9g, CF 2 = CF-O} -CF 2 CF 2 CF 2 COOCH 3 of 1g and a polymerization initiator Was placed in a pressure-resistant glass amble with an internal volume of 50 ml.
After freeze-deaeration was repeated twice, polymerization was carried out at 25 ° C. for 24 hours.
The pressure during the polymerization reaction was lower than atmospheric pressure. as a result,
3.55 g of a polymer was obtained.

This polymer was dissolved in perfluorobenzene and ¹⁹ F-NMR
The spectrum was measured and the structure was confirmed. As a result, the obtained polymer is as well as Such as PAVE derived ring structural unit and CF ₂ = CF-OC
It was found to be a copolymer with a structural unit derived from F ₂ CF ₂ CF ₂ COOCH ₃ , and 93% by weight of a ring structural unit derived from PAVE.

The intrinsic viscosity [η] of this polymer is 0.32 at 30 ℃ in FC-75.
It was found that the degree of polymerization was high.

The glass transition point of the polymer is 64 ° C, and it is a tough and transparent glassy polymer at room temperature. Further, the 10% thermal decomposition temperature was 430 ° C., and the thermal stability was high. Further, this polymer was colorless and transparent.

Example 10 PAVE of _{40g, CF 2 = CF-O} -CF 2 of CF ₂ CF ₂ COOCH ₃ of 5g and a polymerization initiator diisopropyl peroxydicarbonate
It was placed in a pressure-resistant glass ampoule having an inner volume of 100 mg of 10 mg.
After freeze-deaeration was repeated twice, 5 g of CF ₂ = CF ₂ was charged.
Polymerization was carried out at 30 ° C for 72 hours while shaking in an incubator. As a result, 11.8 g of a polymer was obtained.

This polymer was dissolved in perfluorobenzene and ¹⁹ F-NMR
The spectrum was measured and the structure was confirmed. As a result, the obtained polymer is as well as And a cyclic structural unit derived from PAVE such as CF ₂ —CF ₂ and CF ₂ ═CF—O—C
It is a copolymer of a structural unit derived from F ₂ CF ₂ CF ₂ COOCH ₃ and a structural unit derived from CF ₂ = CF ₂ , and the ring structural unit derived from PAVE is 82% by weight. all right.

The intrinsic viscosity [η] of this polymer is 0.42 at 30 ℃ in FC-75.
It was found that the degree of polymerization was high.

The glass transition point of the polymer is 58 ° C, and it is a tough and transparent polymer at room temperature. The 10% thermal decomposition temperature was 421 ℃, indicating high thermal stability. Further, this polymer was colorless and transparent.

Example 11 8 g of PBVE, 1 g of CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and a polymerization initiator Was placed in a pressure-resistant glass ampoule having an internal volume of 50 ml.
After freeze-deaeration was repeated twice, polymerization was carried out at 25 ° C. for 24 hours.
The pressure during the polymerization reaction was lower than atmospheric pressure. as a result,
3.8 g of a polymer was obtained.

This polymer was dissolved in perfluorobenzene and ¹⁹ F-NMR
The spectrum was measured and the structure was confirmed. As a result, the obtained polymer is Or as well as Structural units derived from PBVE such as CF ₂ = CFOCF ₂ C
F (CF ₃ ) OCF ₂ CF ₂ SO ₂ F is a copolymer with a structural unit derived from PBVE and contains 94% by weight of a ring structural unit derived from PBVE.
It turned out to be.

The intrinsic viscosity [η] of this polymer is 0.38 at 30 ° C. in FC-75.
It was found that the degree of polymerization was high.

The glass transition point of the polymer is 92 ° C, and it is a tough and transparent glassy polymer at room temperature. This polymer was colorless and transparent. The adhesion between this polymer and glass was good.

Example 12 PAVE of _{8g, CF 2 = CF-O} -CF 2 CF 2 CF 3 of 2g and a polymerization initiator Was placed in a pressure-resistant glass ampoule having an internal volume of 50 ml.
After freeze-deaeration was repeated twice, polymerization was carried out at 25 ° C. for 24 hours.
The pressure during the polymerization reaction was lower than atmospheric pressure. as a result,
1.85 g of a polymer was obtained.

This polymer was dissolved in perfluorobenzene and ¹⁹ F-NMR
The spectrum was measured and the structure was confirmed. As a result, the obtained polymer is as well as Such as PAVE derived ring structural unit and CF ₂ = CF-OC
A copolymer with a structural unit derived from F ₂ CF ₂ CF ₃ ,
It was found that the ring structural unit derived from PAVE was 89% by weight.

The intrinsic viscosity [η] of this polymer is 0.35 at 30 ° C. in FC-75.
It was found that the degree of polymerization was high.

The glass transition point of the polymer is 61 ° C., and it is a tough and transparent glassy polymer at room temperature. Further, the 10% thermal decomposition temperature was 415 ° C., and the thermal stability was high. Furthermore, this polymer was colorless and transparent, and had an elongation of 250% at 25 ° C.

[Effects of the Invention] The fluorine-containing thermoplastic resin-like polymer of the present invention, which has not been heretofore known, contains an ether bond in the main chain and has an asymmetric ring structure can be easily press-molded, extruded and injection-molded. It is excellent in providing transparent materials with excellent chemical resistance, electrical insulation, thermal stability, strong acid resistance, strong alkali resistance, water resistance, moisture resistance, etc. by molding into optical parts such as lenses. There is an effect. Furthermore, since the polymer of the present invention has a high ultraviolet ray transmittance, it has an effect of substituting various optical parts made of quartz glass. Further, since it has a high infrared transmittance, it has an effect that it can be used for various infrared sensors. Since the polymer of the present invention has a low refractive index, coating a solution of the present resin on an optical component such as a lens has an effect of reducing reflection of light. This resin is a clad material for optical fibers, a material for magneto-optical disks, a protective film for solar cells, a gas separation film, an acrylic resin, a protective film for transparent resins such as polycarbonate and diethylene glycol-bis- (allyl carbonate) resin, and It is recognized that it can be suitably applied as a fiber treating agent.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display area C08F 216: 14) C08F 216: 14) (72) Inventor Shunichi Samejima 2-49, Nakano-ku, Tokyo Central -15 (72) Inventor Motoko Kamba 543 Sanma-cho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (56) Reference JP-A-1-131214 (JP, A) JP-A-63-261204 (JP, A) JP-A-63 -238111 (JP, A) JP-A-63-238115 (JP, A)

Claims (5)

(57) [Claims] 1. A general formula And / or (However, n is 1 or 2) A fluorine-containing thermoplastic resin-like polymer having a molecular weight essentially consisting of a repeating unit group (a) having a ring structure represented by: and having an intrinsic viscosity of at least 0.1. 2. The polymer according to claim 1, wherein the group (a) of repeating units is derived from perfluoroallyl vinyl ether and / or perfluorobutenyl vinyl ether. 3. General formula And / or (Where, n is 1 or 2) repeating units a group of the ring structure represented by (a) and the general formula CF ₂ -CFX (wherein, X is _{F, Cl, O-CF 2} CF 2 CF 3, O- CF ₂ CF (CF ₃ ) OCF
₂ CF ₂ SO ₂ F, O-CF ₂ CF ₂ CF ₂ COOCH ₃ )) and essentially consists of a group (b) of repeating units
Comprising at least 80% by weight of repeating unit group (a),
A fluorine-containing thermoplastic resin-like polymer having a molecular weight such that the intrinsic viscosity is at least 0.1. 4. The polymer according to claim 3, wherein the repeating unit group (a) is derived from perfluoroallyl vinyl ether and / or perfluorobutenyl vinyl ether. 5. The group (b) of repeating units is represented by the general formula CF ₂ = CFX (where X is F, Cl, O-CF ₂ CF ₂ CF ₃ , O-CF ₂ CF (CF ₃ ) OCF.
₂ CF ₂ SO ₂ F, O—CF ₂ CF ₂ CF ₂ COOCH ₃ )) The polymer according to claim 3 or 4, which is derived from a comonomer represented by