JPH05214029A - Fluorine compound and production thereof - Google Patents

Abstract

PURPOSE:To improve polymerizability while avoiding gelation during polymerization by isomerizing a specific fluorine compound in the presence of a fluoride anion source. CONSTITUTION:A fluorine compound (a) represented by formula I (wherein n is 1-3) is isomerized at -50 to 150 deg.C in a polar solvent in the presence of a fluoride anion source in an amount of 0.001-10mol per mol of the compound (a) to thereby obtain a fluorine compound (b) represented by formula II. The compound (b) is radical-polymerized with other monomer at 0-100 deg.C in the presence of a free-radical polymerization initiator to obtain a fluorine copolymer having a side chain containing a double bond. This copolymer is treated with radiation or is heated to 100-400 deg.C in the presence of oxygen, thereby giving an epoxidized copolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel fluorine-containing monomer, a method for producing the same, a copolymer thereof, a curing method and the like.

[0002]

_2. Description of the Related Art CF ₂ = CFO (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF = C of the present invention
FCF ₃ (n = 1 to 3) is a novel compound that has not been published in the literature and has two types of double bonds with different reactivities. Such an example was known to be CF ₂ = CFOCF ₂ CF = CF ₂ , CF ₂ = CFOCF ₂ CF ₂ CF = CF ₂ . Further, a compound having two or more double bonds with the same reactivity is, for example, CF ₂ = CFO (CF ₂ ) _n OCF = CF ₂ , CF ₂ = CF
(CF ₂ ) _n CF = CF ₂ was also known. However, in terms of introducing a cross-linking site consisting of a double bond into the fluoropolymer, the former undergoes cyclopolymerization and there are few remaining double bonds, and the latter divinyl ether compound gels during polymerization,
The non-vinyl ether type diene monomer has a drawback that it has low polymerizability. Further, in JP-A-1-143844, CF ₂ = CF
Synthesis of a compound of O (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF ₂ CF = CF ₂ is described, but no description is made of a copolymer.

[0003]

DISCLOSURE OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art, a fluorine-containing monomer, a copolymer thereof and a curing method thereof, and a method of curing the copolymer. The present invention newly provides an epoxy derivative.

[0004]

That is, the present invention firstly provides a novel fluorine-containing compound represented by the formula (1) (n is an integer of 1 to 3), and CF ₂ = CFO (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF = CFCF ₃ Formula (1) Second, the fluorine-containing compound represented by Formula (2) (n is an integer of 1 to 3) is CF ₂ = CFO (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF ₂ CF = CF ₂ Formula (2) To obtain a compound of the general formula (1) characterized by isomerizing in the presence of a fluorine anion source. Thirdly, the present invention provides a novel production method, and thirdly, a radical-copolymerization of the fluorine-containing compound represented by the formula (1) and another monomer is carried out to a side chain portion. A method for producing a fluorine-containing copolymer having a heavy bond, and fourth,
A fifth aspect of the present invention provides a fluorine-containing copolymer obtained by radically copolymerizing a fluorine-containing compound represented by the formula (1) and another monomer. Fifthly, a fluorine-containing copolymer having a double bond in a side chain portion is provided. The present invention provides a method for curing a fluorocopolymer, which comprises subjecting the polymer to radiation treatment. Sixthly, the fluorocopolymer having a double bond in the side chain is present in the presence of oxygen gas. The present invention provides a method for producing a copolymer having an epoxy group, which comprises heating to 100 to 400 ° C under the condition.

The compound of formula (2) used in the present invention is
For example, it can be synthesized as follows (Japanese Patent Application Laid-Open No. 1-1.
43844).

That is, after reacting iodine chloride with trifluorochloroethylene at a low temperature, tetrafluoroethylene is reacted in the presence of a radical initiator and oxidized with fuming sulfuric acid or the like. Further, by reacting hexafluoropropylene oxide in the presence of cesium fluoride or the like at a low temperature to generate vinyl ether by thermal decomposition, and dechlorinating using a dehalogenating agent such as metallic zinc, a fluorine-containing compound of the formula (2) Can be obtained.

[0007]

[Chemical 1]

The compound of formula (1) of the present invention can be synthesized by isomerizing the compound of formula (2) in a polar solvent in the presence of a fluorine anion source. As the fluorine-containing anion source used in the catalyst, an alkali metal fluoride or ammonium fluoride salt is used, and the addition amount thereof is 0.
It is 001 to 10 times, preferably 0.005 to 0.5 times. Examples of the polar solvent used include acetonitrile, 1,4-dioxane, diglyme, triglyme,
Examples include tetraglyme, dimethyl sulfoxide, tetrahydrofuran and the like. The reaction temperature is -50 ° C to 150
C, preferably 0 to 100 ° C.

The compound of the present invention can introduce a double bond into a side chain as a crosslinking site by copolymerizing with various monomers. The monomer to be copolymerized is not particularly limited, but particularly tetrafluoroethylene, hexafluoropropylene, perfluoro (alkyl vinyl ether), perfluoro (allyl vinyl ether), perfluoro (butenyl vinyl ether), perfluoro (2,2) -Dimethyl-1,3-dioxole), chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, fluoroethylene, (perfluoroalkyl) ethylene, etc. An excellent crosslinkable fluorine-containing copolymer can be obtained.

Radical polymerization is used as a polymerization method. That is, the polymerization method is not particularly limited as long as it radically proceeds, but bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization can be used. As the polymerization initiator used in the present invention, a free radical polymerization initiator is preferable, and examples thereof include bis (fluoroacyl) peroxides, bis (chlorofluoroacyl) peroxides, dialkylperoxydicarbonates, diacyl peroxides, Examples thereof include oxyesters, azobis compounds, persulfates and the like.

As the polymerization medium, CFC 1 in solution polymerization is used.
1 (CFCl ₃ ), freons such as Freon 113 (CF ₂ ClCFCl ₂ ), tert-butanol, and the like, and in suspension polymerization or emulsion polymerization, water or a mixed medium with the above-mentioned solvent is used. The polymerization temperature can be selected from the range of 0 to 100 ° C. The polymerization pressure varies depending on the monomer used, but for copolymerization with tetrafluoroethylene, for example, the gauge pressure can be selected from the range of 0.5 to 30 kg / cm ² G.

Since the fluorine-containing copolymer thus obtained has a highly reactive double bond in the side chain, an electron beam,
It can be cured by radiation such as ultraviolet rays and γ rays. In the case of UV curing, a photopolymerization initiator may be added if necessary. The method of radiation treatment is useful in the field of electric wire coating with a fluorine-containing copolymer, and electron beam irradiation is preferably used.

It is considered that the curing proceeds by the cycloaddition reaction (formation of a four-membered ring) of the double bond introduced into the side chain, polymerization and oligomerization.

Since the double bond is highly reactive in the air at high temperature, if the double bond remains in the cured copolymer, heat treatment in air stabilizes the physical properties. You can also

It is also possible to stabilize the unreacted double bond by treating the cured product with gaseous halogen such as fluorine gas. Fluorine gas may be diluted with an inert gas such as nitrogen gas before use.

In the fluorine-containing copolymer of the present invention, the polymer unit based on the fluorine-containing compound represented by the formula (1) is
It is preferable that the content is 0.01 mol% or more.
If the proportion of the polymerized units is too small, it becomes difficult to obtain a cured product which is the object of the present invention. Further, the upper limit is not particularly set, but it is sufficient if the content is 40 mol%.

The balance is a unit based on a radical-polymerizable monomer, and a unit based on a fluorine-containing monomer is 60.
It is preferably from 99.99 mol% because a fluorine-containing copolymer excellent in chemical resistance and heat resistance or a cured product thereof can be obtained.

In the present invention, the molecular weight of the fluorinated copolymer is not particularly limited, and may be from a liquid at room temperature to a solid at room temperature but exhibiting melt fluidity at high temperature, or at room temperature. It can be applied to high molecular weight substances that do not show fluidity at high temperatures. The low molecular weight substance can be used as a raw material for rubber, and a substance that is solid at room temperature but exhibits melt fluidity at high temperature provides a thermoplastic molding material having excellent moldability and is cured by radiation treatment. Further, the low-molecular weight substance which is liquid at room temperature can be used as it is for coating materials.

The present invention can be widely applied from rubber to resin by selecting the copolymer composition. To prepare a cured rubber, an appropriate amount of a fluorine-containing compound represented by the formula (1) used in the present invention is added to a conventionally known polymerization composition, copolymerized, and then cured by radiation treatment or the like. It is possible to For example, by containing a perfluoro (alkyl vinyl ether) in an amount of 10 to 40 mol% and a perfluorodiene monomer in an amount of 0.01 to 20 mol% and curing a terpolymer with tetrafluoroethylene (the balance), elasticity can be obtained. You can get a body.

On the other hand, in the field of resins, a thermoplastic copolymer can be prepared by selecting the composition and molecular weight, and when cured by radiation treatment, a cured resin exhibiting no melt fluidity can be obtained. ..

In both rubber and resin, a perfluorinated curable polymer and cured product can be synthesized by selecting a completely fluorine-substituted monomer as a radically polymerizable monomer. However, the term "perfluoro copolymer" as used herein refers to a copolymer in which the ratio of the number of fluorine atoms to the total number of atoms excluding carbon atoms and oxygen atoms contained in the copolymer is 95% or more. When such a perfluoro copolymer is sufficiently cured, a cured product of perfluoro having excellent heat resistance and chemical resistance can be obtained.

In particular, it is a copolymer of the fluorine-containing compound represented by the formula (1) and tetrafluoroethylene, and the unit based on each is 0.01 to 40 mol%, 99.99 to.
When it is contained at 60 mol%, the cured product has well-balanced mechanical properties and resistance to various chemicals.
In this case, it is preferable that the uncured fluorocopolymer be solid at room temperature and have a molecular weight such that it exhibits fluidity at high temperatures. Those that are not solid at room temperature are not preferable because they are complicated to handle during molding and transportation. Also, those that do not show fluidity at high temperature are inferior in molding workability,
In addition, the cured product may not have the expected mechanical strength. The preferable molecular weight for melt molding depends on the molding conditions, but the volume flow rate (measured according to the method shown in the examples) is 0 at a temperature of 20 to 300 ° C. with a load of 5 to 50 kg. .1 to 100
The value is 0 mm ³ / sec.

Furthermore, it is preferable that the unit based on the fluorine-containing compound represented by the formula (1) is 0.5 to 30 mol%. If the amount of this unit is too small, a crosslinked cured product is obtained, but improvement in mechanical properties may not be sufficiently achieved. Further, when the amount of this unit is large, the copolymerization reaction becomes slow, and it becomes difficult to obtain a high molecular weight product which is easy to handle, which is not preferable.

The copolymer of the present invention has a double bond in the non-terminal portion of the side chain, but can be converted into a copolymer having an epoxy structure in the side chain by oxidation. For example, in air, 1
Epoxy can be easily introduced by air oxidation by heating to 00 to 400 ° C, preferably 150 to 350 ° C, and this can also be used as a crosslinking site.

[0025]

【Example】

Example _{1 CF 2 = CFOCF 2 CF (} CF 3) of _{OCF 2 CF 2 CF = CF 2} 266g, with a 3.5g of potassium fluoride (KF), the 133g of acetonitrile dried over molecular sieves reflux condenser 5
The mixture was added to a 00 cm ³ four-necked flask and refluxed for 7 hours with sufficient stirring. After cooling, the lower layer was collected using a separating funnel and distilled at a normal pressure (boiling point 124.5 ° C) to obtain CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF = CFCF ₃ 78.4 g. It was ^{According to 19} F-NMR and gas chromatograph analysis, t
The ratio of rans body to cis body was 9: 1.

Elemental analysis, measured value F68.41%; C24.36% (calculated value F68.45%; C24.34%)

[0027]

[Chemical 2]

¹⁹ F-NMR (δppm, CFCl ₃ standard) F ¹ : -113, F ¹ : -122, F ² : -136, F ³ : -85, F ⁴ : -146, F ⁶ : -80, ^{F 7: -70, F 7:} -158, F 7: -159, F 10: -69

Coupling constant (Hz) JF ¹ F ² = 84, JF ¹ F ² = 113, JF ² F ³ = 65, JF ⁸ F ⁹ = 140

[0030]

[Chemical 3]

¹⁹ F-NMR (δppm, CFCl ₃ standard) F ¹ : -113, F ² : -122, F ³ : -136, F ⁴ : -85, F ⁵ : -146, F ⁶ : -80, F ⁷ : -68, F ⁸ : -141, F ⁹ : -142, F ¹⁰ : -66

Coupling constant (Hz) JF ¹ F ² = 84, JF ¹ F ³ = 113, JF ² F ³ = 65

Example 2 CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF in a 100 cm ³ autoclave
₂ CF = CFCF ₃ (hereinafter abbreviated as PGBV2) 24.4 g, Freon 113 20.6 g, and diisopropyl peroxydicarbonate 45 mg were charged, cooled with liquid nitrogen and deaerated, and then tetrafluoroethylene at 40 ° C. Was sequentially added and the pressure was maintained at 7 kg / cm ² . After reacting for 21 hours, reprecipitation was repeated 3 times with carbon tetrachloride and vacuum drying was performed at 60 ° C. to obtain 5.0 g of a copolymer. In the infrared absorption spectrum, absorption of an internal olefin was observed at 1725 cm ^-1 . The volumetric flow rate of the obtained copolymer was measured with a Koka type flow tester (manufactured by Shimadzu Corporation) at 200 ° C. under a load of 30 kg and using a die of 1 mmφ and a length of 2 mm. The volumetric flow rate was 30 mm ³ / It was seconds. When the composition of the copolymer was examined by NMR, the proportion of PGBV2 was 14 mol%.

Example 3 1.66 g of perfluoropropyl vinyl ether and 1.38 of PGBV2 were placed in a 100 cm ³ autoclave.
g, Freon 113 117.3 g, methanol 45 m
g, 4.0 g of a 5% solution of perfluorobutanoyl peroxide (solvent Freon 113) was added, and the pressure was 2 kg / cm ² while sequentially adding tetrafluoroethylene at 25 ° C.
Held in. After reacting for 2.5 hours, 3 with n-hexane
Reprecipitation was repeated twice and vacuum drying was performed at 60 ° C. to obtain 9.6 g of a copolymer. The volume flow rate of the obtained copolymer was set to 350
When measured in the same manner as in Example 2 at 9 ° C., it was 9 mm ³ /
It was seconds.

Example 4 The copolymer obtained in Example 2 was heat-treated in air at 250 ° C. for 16 hours and pressed at 220 ° C. The infrared absorption spectrum of the film was 1725 cm ⁻¹ . The absorption of the bond disappeared, and a strong absorption of an epoxy group newly generated by air oxidation of the double bond was newly observed at 1500 cm ^-1 .

Example 5 The copolymer obtained in Example 2 was formed into a film by hot pressing and irradiated with an electron beam. 50Mrad, 100Mrad
When the dynamic viscoelasticity of the irradiated film was measured, it was revealed that the change in elastic modulus was small in the region of 150 to 250 ° C. and that the film was crosslinked in all cases. The elastic modulus at that time was about 1 × 10 ⁸ dyn / cm ² .

Example 6 PGBV2 of 4.52 was placed in a 100 cm ³ autoclave.
g, Freon 113 95.5 g, diisopropyl peroxydicarbonate 100 mg, methanol 200 mg
Was added, and the pressure was maintained at 3 kg / cm ² G while sequentially adding tetrafluoroethylene at 40 ° C. After reacting for 9.5 hours, reprecipitation was repeated 3 times with n-hexane to 60 ° C.
Vacuum drying was performed to obtain 7.5 g of a fluorocopolymer. When the volume flow rate of the obtained copolymer was measured at 300 ° C. in the same manner as in Example 2, it was 172 mm ³ / sec. This copolymer was formed into a film by hot pressing, and the elastic modulus was measured. Room temperature elastic modulus is 6 × 10 ⁹ dyn / cm ² , 200 ° C.
The elastic modulus was 5 × 10 ⁸ dyn / cm ² .
Elastic modulus after irradiation with 50 Mrad of electron beam is 1 × 10 ⁹
It was dyn / cm ² .

Example 7 6.65 PGBV2 was added to a 100 cm ³ autoclave.
g, 194 g of Freon 113, 6.5 g of perfluorobutanoyl peroxide 5% solution (solvent Freon 113),
72 mg of methanol was added, and the pressure was maintained at ² kg / cm ² G while sequentially adding tetrafluoroethylene at 25 ° C. After reacting for 2.5 hours, reprecipitation was repeated 3 times with n-hexane and vacuum drying was performed at 60 ° C. to obtain 15.7 g of a fluorocopolymer. The volume flow rate of the obtained copolymer was adjusted to 34
0 ℃ respectively 1.2mm at 360 ° C. was measured in the same manner as in Example 2 ³ / sec was 9.9 mm ³ / sec. This copolymer was formed into a film by hot pressing, and the elastic modulus was measured. Room temperature elastic modulus is 5 × 10 ⁹ dyn / cm ² , 2
The elastic modulus at 00 ° C. was 5 × 10 ⁹ dyn / cm ² . The elastic modulus at 200 ° C. after irradiation with 50 Mrad of electron beam was 1.1 × 10 ⁹ dyn / cm ² .

Comparative Example 1 Instead of PGBV2, an equimolar amount of CF ₂ = CFO (CF ₂ ) ₅ OCF
= A copolymer was synthesized in the same manner as in Example 2 except that CF ₂ was used. About this copolymer, 20, 100, 20
The volume flow rates measured at 0 and 300 ° C. in the same manner as in Example 2 were 0 mm ³ / sec.

Comparative Example 2 Instead of PGBV2, an equimolar amount of CF ₂ = CFO (CF ₂ ) ₅ OCF
= A copolymer was synthesized in the same manner as in Example 3 except that CF ₂ was used. This copolymer did not exhibit melt flowability as in Comparative Example 2.

[0041]

INDUSTRIAL APPLICABILITY The fluoropolymer having a double bond at the non-terminal portion as described above can be crosslinked by incorporating a chemical crosslinking agent composed of a peroxy compound and a crosslinking accelerator composed of a polyallyl compound. Such an example is disclosed in JP-A-5
6-70009. That is, CF ₂ = CFOCF = CF
The copolymer of CF ₃ and tetrafluoroethylene / propylene, or tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride has a double bond at the non-terminal side chain, and is a chemical cross-linking agent consisting of a peroxy compound,
Vulcanization becomes possible by adding a crosslinking accelerator composed of a polyallyl compound. Further, since it has a double bond as a cross-linking site, cross-linking by radiation such as γ-rays, electron beams, and ultraviolet rays, and photo-cross-linking by adding a bifunctional compound such as a tetrazonium salt or a bisazide compound are also possible.

The copolymer of the present invention has a double bond at the non-terminal portion of the side chain, but can be converted into a copolymer having an epoxy structure in the side chain by oxidation. Therefore, it can be converted into a ketone by isomerization in the presence of a fluorine anion source such as cesium fluoride or potassium fluoride. When converted to a ketone, it has radical reactivity like hexafluoroacetone and can perform radical addition reaction or radical copolymerization. Further, perfluoroketone can generate a Schiff base by reacting with a primary amine. In addition to this, various ionic reactions are known for perfluoroketone, and various functional groups can be introduced into side chains by the reaction.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C08F 299/02 MRS 7442-4J

Claims (7)

[Claims] 1. A fluorine-containing compound represented by the formula (1) (where n is an integer of 1 to 3). CF ₂ = CFO (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF = CFCF ₃ formula (1) 2. A formula (2) (where n is an integer of 1 to 3) CF ₂ = CFO (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF ₂ CF = CF ₂ Formula (2) A fluorine-containing compound represented by the formula (1) (where n
Is an integer of 1 to 3). CF ₂ = CFO (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF = CFCF ₃ formula (1) 3. A double bond in a side chain characterized by radically copolymerizing a fluorine-containing compound represented by the formula (1) (where n is an integer of 1 to 3) with another monomer. A method for producing a fluorinated copolymer having: CF ₂ = CFO (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF = CFCF ₃ formula (1) 4. The method according to claim 3, wherein all of the other monomers or at least one of the other monomers is a fluorine-containing monomer, and the side chain has a double bond. Method for producing fluorocopolymer. 5. A fluorine-containing copolymer obtained by radically copolymerizing a fluorine-containing compound represented by the formula (1) (where n is an integer of 1 to 3) and another monomer. CF ₂ = CFO (CF ₂ CF (CF ₃ ) O) _n CF ₂ CF = CFCF ₃ formula (1) 6. A method for curing a fluorinated copolymer, which comprises subjecting the copolymer obtained by the method according to claim 3 to radiation treatment. 7. A method for producing a copolymer having an epoxy group, which comprises heating the copolymer obtained by the method according to claim 3 to 100 to 400 ° C. in the presence of oxygen gas. Method.