JPH0822829B2 - Novel fluorovinyl ether and its copolymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel fluorovinyl ether and a copolymer thereof, more specifically, a fluorovinyl ether useful for modifying a polymer containing an ethylenically unsaturated compound, and It relates to a copolymer obtained by copolymerizing a fluorovinyl ether.

[Prior Art] Various copolymers ranging from resinous to elastomeric can be obtained by a copolymerization reaction of a fluoroolefin with another fluoroolefin or a fluoroolefin with a fluorine-free olefin. These copolymers can be molded into mechanical parts such as O-rings, flange seals, gaskets, diaphragms and liners, and are particularly useful when special resistance to heat and corrosive fluids is required.

Vinylidene fluoride / hexafluoropropylene, tetrafluoroethylene / propylene, tetrafluoroethylene / perfluoroalkyl vinyl ether, vinylidene fluoride / perfluoroalkyl vinyl ether, etc. have been conventionally known as copolymers giving fluorine-containing elastomers. It has been put to practical use as a useful elastomer.

These elastomers have excellent heat resistance, oil resistance, chemical resistance, etc. that hydrocarbon-based elastomers do not have, but on the other hand, they are not sufficient in terms of low temperature characteristics, and there is a problem in use in cold regions.

As a method for solving this problem, a blending method such as co-vulcanization with silicon rubber is performed, but in order to greatly improve low temperature characteristics, silicon rubber is mainly used as a main component, and the characteristics of the fluororubber are Is sacrificed. Further, it has been attempted to blend a certain kind of plasticizer, but the plasticizer may be separated depending on the use conditions, and an intended elastomer having low temperature resistance has not been obtained yet.

On the other hand, by introducing an ether bond into the main chain of the polymer,
From attempts to improve low-temperature properties, ionic polymerization reaction of hexafluoropropylene oxide, radical polymerization reaction of fluorine-containing ketone, and condensation reaction of fluorine-containing polyether have been investigated, but at present, practical elastomers. Has not come to get.

Attempts have also been made to improve the low temperature characteristics by introducing an ether bond into the side chain. For example, CF ₂ = CFORf
(Here, Rf is CF ₃ , C ₂ F _5, or C ₃ F _7, etc.) and vinylidene fluoride or tetrafluoroethylene, a flexible copolymer is obtained by a copolymerization reaction, The glass transition temperature of these copolymers does not fall sufficiently even if the content of the above vinyl ether is increased as much as possible.

Among the fluorovinyl ethers, fluorovinyl ethers having a plurality of theether bonds are known to be effective for improving the low temperature characteristics, and have a certain low temperature characteristic due to a copolymerization reaction with a fluorine-free olefin or a fluoroolefin. A fluoroelastomer has been obtained (JP-A-57-18710, JP-B-61-50486).
No., Japanese Patent Publication No. 61-57324). However, the low temperature properties of these fluoroelastomers are also not sufficient.

[Object of the Invention] It is an object of the present invention to provide a novel fluorovinyl ether that gives a fluorine-free olefin or a copolymer with a fluoroolefin which is excellent in low temperature properties in addition to heat resistance, oil resistance and chemical resistance. It is in.

An object of the present invention Configuration of the Invention] the general _{formula: RfOCF 2 CF 2 CF 2 n} OCF = CF 2 (I) [ wherein, Rf is a perfluoroalkyl group having C ₁ -C _5, n is 2 to 4 Is an integer. ] It is achieved by the fluoro vinyl ether shown by these.

According to the present invention, the general formula: RfOCF in _{2 CF 2 CF 2 n OCF =} CF 2 (I) [ wherein, Rf is a perfluoroalkyl group having C ₁ -C _5, n is an integer of 2 to 4. ] The copolymer which has the repeating unit derived from the fluoro vinyl ether shown by these, and the repeating unit derived from at least 1 type of ethylenically unsaturated compound is provided.

The fluorovinyl ether of the present invention is extremely effective in improving the low temperature properties of the fluoroelastomer as compared with the conventional fluorovinyl ether.

Typical fluorovinyl ethers (I) of the present invention are as follows. Above all, n
2 to 4 are particularly preferable.

CF ₃ (OCF ₂ CF ₂ CF ₂ ) ₂ OCF = CF ₂ CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₂ OCF = CF ₂ CF ₃ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = CF ₂ CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = CF ₂ CF ₃ (OCF ₂ CF ₂ CF ₂ ) ₄ OCF = CF ₂ CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₄ OCF = CF ₂ fluorovinyl ether (I) can be synthesized, for example, from the corresponding acid fluoride as follows.

[In the above formula, R is an alkyl group or a cycloalkyl group or an aryl group which may have a substituent, and Rf and n have the same meanings as described above. The compound (II) can be easily obtained by the method described in JP-A No. 61-113616.

Compound (III) can be obtained by reacting compound (II) with hexafluoropropylene oxide.
As the solvent, glymes such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether and acetonitrile can be used. Also, as a catalyst,
Cesium fluoride, potassium fluoride, silver fluoride, ammonium fluoride, tetraalkylammonium fluoride, or sulfonium fluoride can be used.

The reaction temperature and the reaction time are not particularly limited, but the reaction from compound (II) to compound (III) is -3
It is preferable to carry out at a temperature of 0 to + 50 ° C. for 3 to 20 hours.

Compound (IV) is compound (III) while cooling with ice water.
It can be synthesized by slowly reacting with alcohol.

Compound (V) can be synthesized by reacting compound (IV) with an alkali hydroxide such as sodium hydroxide at room temperature to 100 ° C for several hours.

By heating the compound (V) to 150 to 250 ° C. under reduced pressure or in an atmosphere of an inert gas such as nitrogen, the objective product fluorovinyl ether (I) is obtained.

The ethylenically unsaturated compound copolymerized with the fluorovinyl ether (I) may be any known monomer. Examples of the ethylenically unsaturated compound are fluorine-free ethylenically unsaturated compounds such as ethylene, propylene, butylene, carboxylic acid vinyl ester (for example, vinyl acetate), vinyl ether (for example, methyl vinyl ether, ethyl vinyl ether), vinyl chloride, vinylidene. Chloride, acrylic acid and methacrylic acid, tetrafluoroethylene which is a fluorine-containing ethylenically unsaturated compound, trifluoroethylene, chlorotrifluoroethylene, vinyl fluoride, vinylidene fluoride, hexafluoropropylene, pentafluoropropylene, hexafluoroisobutene, Perfluorocyclobutene, perfluoro (methylcyclopropylene), perfluoroallene, α, β, β-trifluorostyrene, perfluorostyrene, Perfluoroalkyl vinyl ethers (e.g., perfluoro (methyl vinyl ether), perfluoro (propyl vinyl ether)), perfluoro (alkyl vinyl polyether)
Examples thereof include polyfluoroacrylic acid, polyfluorovinylacetic acid, polyfluorovinyl ether sulfonic acid and polyfluorodienes.

The amount of fluorovinyl ether (I) in the copolymer is
It may be different depending on the type of copolymer produced. Generally, the amount of fluorovinyl ether (I) is preferably 0.01 to 60 mol% based on the total amount of the copolymer, for performance and economical reasons. To improve the low temperature properties, the amount of fluorovinyl ether (I) is preferably 1 to 60 mol%, more preferably 2 to 50 mol%.

The polymerization can be carried out in the form of bulk, suspension, solution polymerization, or emulsion polymerization using a water-soluble or oil-soluble peroxide in the presence of a perfluoroemulsifier. Solvents used for solution polymerization include dichlorodifluoromethane, trichlorofluoromethane, chlorodifluoromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,2-dichloro-1,1,2, 2-tetrafluoroethane, 1,1,2,2-tetrachloro-1,2-difluoroethane,
Highly fluorinated solvents such as perfluorocyclobutane and perfluorodimethylcyclobutane are preferably used.

In the bulk, suspension, and solution polymerization forms, organic initiators can generally be used. Among the most preferred initiators are the highly fluorinated peroxides, (Rf-COO
₂ ) A diacyl peroxide represented by (wherein Rf is a perfluoroalkyl group, an ω-hydroperfluoroalkyl group or a perchlorofluoroalkyl group) is particularly preferable.

The number average molecular weight of the copolymer is preferably 10,000 to
It is 500,000, more preferably 30,000 to 300,000.

The molecular weight can be easily adjusted by adding a chain transfer agent. As the chain transfer agent, hydrocarbons having 4 to 6 carbon atoms, alcohols, ethers, organic halides (for example, CCl ₄ , CBrCl ₃ , CF ₂ BrCFBrCF ₃ , CF ₂ I ₂ ) and the like can be advantageously used. . When a fluorocarbon iodide (eg CF ₂ I ₂ , I (CF ₂ ) ₄ I, CF ₂ = CFCF ₂ CF ₂ I) is used as a chain transfer agent, iodine binds to the molecular end and is still radically active. Since it is in a state, there is an advantage that peroxide addition using peroxide as a radical source is possible in the presence of a polyfunctional unsaturated compound such as triallyl isocyanurate and triallyl cyanurate.

The polymerization temperature is determined by the decomposition temperature of the initiator. The polymerization pressure is determined by the kind of comonomer that can be copolymerized with the fluorovinyl ether (I). That is, the content of the fluorovinyl ether (I) in the produced polymer can be determined by a conventional method based on the copolymerization reactivity ratio with the comonomer so that it falls within the above range.

It is necessary to select the vulcanization method depending on the kind of the comonomer that can be copolymerized with the fluorovinyl ether (I). For example, when the comonomer is vinyl denfluoride, trifluoroethylene, vinyl fluoride, etc., vulcanization by a generally well-known polyamine type, aromatic polyol-vulcanization accelerator type, etc. is possible. is there. On the other hand, in the case of tetrafluoroethylene, chlorotrifluoroethylene, and ethylene, it is impossible or extremely difficult to vulcanize with these vulcanization systems, so it is necessary to add a monomer having a vulcanization site. There is. As a monomer having such a vulcanization site, CF ₂ = CFO (CF ₂ ) mC
N, CF ₂ = CFO (CF ₂ ) mBr, CF ₂ = CFO (CF ₂ ) mI, CH ₂ = CHO
CH ₂ CH ₂ Cl, CF ₂ = CFCF ₂ COOH, (Here, m usually represents an integer of 1 to 8) and the like. Further, as described above, when fluorocarbon iodide is used as the chain transfer agent, a copolymer which can be easily vulcanized by peroxide can be obtained.

The amount of organic peroxide compound used is 100
The amount is 0.05 to 10 parts by weight, preferably 1.0 to 5 parts by weight.

As the organic peroxide compound, generally, a compound that easily generates a peroxy radical in the presence of heat or a redox system is preferable, for example, 1,1-bis (t-butylperoxy) -3,5,5-trimethyl. Cyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-
Butyl ruperoxide, t-butyl cumyl peroxide, dicumyl peroxide, α, α′-bis (t-
Butylperoxy) p-diisopropylbenzene, 2,5
-Dimethyl-2.5-di (t-butylperoxy) hexane, 2,5-dimethyl-2.5-di (t-butylperoxy) hexane
-Hexyne-3, benzoyl peroxide, t-butylperoxybenzene, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, etc. Can be illustrated. Among them, preference is given to those of the dialkyl type. Generally active -O-
The type and amount of peroxide used are selected in consideration of the amount of O-, the decomposition temperature, and the like.

Further, when an organic peroxide compound is used, remarkable curing can be observed by appropriately using a crosslinking aid or a co-crosslinking agent together. The crosslinking aid or co-crosslinking agent is basically effective as long as it has a reaction activity with respect to a peroxy radical and a polymer radical, and the kind is not particularly limited. Preferred are triallyl cyanurate, triallyl isocyanurate, triallykyl formal, triallyl trimellitate, N, N'-
Examples thereof include m-phenylene bismaleimide, dipropargyl terephthalate, diallyl phthalate, tetraallyl terephthalamide, triallyl phosphate and the like.
The amount used is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the copolymer.
In addition, as blending and co-crosslinking, silicone oil, silicone rubber, ethylene / vinyl acetate copolymer, 1,2-polybutadiene, fluorosilicone oil, fluorosilicone rubber, fluorophosphazene rubber, vinylidene fluoride / hexafluoro Propylene copolymers, vinylidene fluoride / tetrafluoroethylene / hexafluoropropylene copolymers, hexafluoropropylene / ethylene copolymers, tetrafluoroethylene / propylene copolymers, and other radically reactive polymers Used. The amount of these used is not particularly limited, but should not be so large as to essentially impair the properties of the copolymer of the present invention.

Furthermore, pigments, fillers, reinforcing agents, etc. for coloring the copolymer are used. Commonly used fillers or reinforcing agents include carbon black, TiO ₂ and S for inorganic materials.
iO ₂ , clay, talc, etc. are organic substances such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polychlorotrifluoroethylene,
Examples thereof include fluoropolymers such as tetrafluoroethylene / ethylene copolymer and tetrafluoroethylene / vinylidene fluoride copolymer.

As a means for mixing these curing components, an appropriate method is adopted depending on the viscoelasticity and morphology of the material.
Ordinary open rolls and powder mixers are used. In the case of a liquid, a usual mixer is used as appropriate. Of course, it is also possible to dissolve or disperse the solid components in a solvent and disperse and mix them.

The vulcanization temperature and time depend on the type of peroxide used, but normally press vulcanization is performed at a temperature of 120 to 200 ° C for 5 to 30 minutes, and oven vulcanization is performed at a temperature of 150 to 250 ° C for 1 minute.
Do ~ 24 hours.

The copolymer of the present invention is effectively used as a general molding material, a sealant, an adhesive, a paint, etc. in a place where low temperature resistance is required in addition to heat resistance, oil resistance, chemical resistance, solvent resistance, etc. To be done.

[Preferred Aspects of the Invention] The present invention will be specifically described below with reference to Reference Examples, Examples and Comparative Examples.

Reference Example 1 2,2,5,5,6,6,9,9,10,10,13,13,14,14,15-pentadecafluoro-4,8,12-trioxa-pentadecanoylfluoride (FCH ₂ CF ₂ CF ₂ OCH ₂ CF ₂ CF ₂ OCH ₂ CF ₂ CF ₂ OCH ₂ CF ₂ CO
Production of F) In a 5 l flask equipped with a stirrer, a cooler and a dropping funnel,
1059 g of 2,2,3-trifluoropropionyl fluoride described in JP-A-60-136536, 5 g of crown ether, 40 g of cesium fluoride, 1000 ml of monoglyme.
Then, 1515 g of 2,2,3,3-tetrafluorooxetane was slowly added dropwise under stirring at 15 ° C to 20 ° C over 3 hours and 30 minutes. After completion of dropping, stirring was continued for 5 hours while maintaining the internal temperature at 15 ° C to 20 ° C. The reaction solution was then distilled under reduced pressure to give the title compound 2,2,5,5,6,6,9,9,10,10,13,13,14,14,15, -pentadecafluoro-4,8. 326 g of 12,12-trioxa-pentadecanoylfluoride was obtained. Boiling point 123 ℃ / 5mmHg.

Reference Example 2 160 g of the acid fluoride obtained in Reference Example 1 was charged into a stainless steel 100 ml container equipped with a cooler, and a fluorine / nitrogen (volume ratio 20/80) mixed gas was passed at a flow rate of 150 ml / min while stirring with a magnetic stirrer. And allowed to react at 100 ° C. for 97 hours. The reaction product is a mixture of CF ₃ CF ₂ OCF ₂ CF ₂ CF _{2 2} OCF ₂ CF ₂ COF 85 mol% CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ CF _{2 2} OCF ₂ CF ₃ 15 mol% according to the analysis. I knew it was. Yield 188g.

Reference Example 3 By the same method as in Reference Example 2, the reaction was carried out for 120 hours with 180 g of acid fluoride. According to the analysis, the reaction product is CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ CF _{2 2} OCF ₂ CF ₂ COF 95 mol% CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ CF _{2 2} OCF ₂ CF ₃ 5 mol% It was found to be a mixture. Yield 205g.

Reference Example 4 In the same manner as in Reference Example 2, the acid fluoride was used in an amount of 200 g and reacted for 96 hours. According to the analysis, the reaction product is CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ CF _{2 2} OCF ₂ CF ₂ COF 92 mol% CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ CF _{2 2} OCF ₂ CF ₃ 8 mol% It was found to be a mixture. Yield 240g.

Example 1 Production of Perfluorovinyl Ether CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ CF _{2 3} OCF = CF ₂ 13.3 g of cesium fluoride and 27 ml of tetraglyme 1
Mixture of perfluoropolyether in four neck flask
CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₂ OCF ₂ CF ₂ COF / CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂
CF ₂ ) ₂ OCF ₂ CF ₃ (molar ratio 85/15) 234 g was charged, and hexafluoropropylene oxide was added from the cylinder at a reflux rate with a dry ice cooler while maintaining the temperature in the flask at + 10 ° C under stirring, The reaction was carried out. From the start of the reaction 3.
After 5 hours, stop adding hexafluoropropylene oxide, add 30 ml of methanol while cooling with ice water, wash with water several times, and by distillation, Separated. Yield 161g. Boiling point 97-98 ℃ / 5mmHg.

Subsequently, the produced methyl ester was placed in one flask, and saponification reaction was carried out at 40 to 60 ° C. with 5 wt% NaOH / methanol solution using phenolphthalein as a pH indicator. From the slightly pink colored viscous solution, methanol was distilled off under reduced pressure, and vacuum drying was carried out at 120 ° C. until a constant weight was reached to obtain 162 g of a solid matter.

Next, this solid was crushed and put into a 500 ml flask connected to a trap that had been sufficiently cooled with dry ice, and was thoroughly replaced with nitrogen gas. When heating was continued from 150 ° C. to 240 ° C. for 4 hours, 134 g of liquid accumulated in the trap. This is distilled to give the title compound perfluoro (3,7,
11,15-Tetraoxa-1-octadecene) CF ₃ CF ₂ CF ₂ (O
CF ₂ CF ₂ CF ₂ ) ₃ OCF = CF ₂ 69 g was obtained.

Boiling point 70-71 ℃ / 6mmHg.

Example 2 In the same manner as in Example 1, the perfluoropolyether mixture CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₂ OCF ₂ CF ₂ COF / CF ₃ CF ₂ CF _{2 was used.}
(OCF ₂ CF ₂ CF ₂ ) ₂ OCF ₂ CF ₃ (molar ratio 91/9) 632 g to perfluorovinyl ether CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = CF ₂ 24
I got 0g.

Example 3 Pure water 1 and C ₃ as an emulsifier were placed in a polymerization tank having an internal volume of 3 liters.
_{F 7 OCF (CF 3) CF} 2 OCF (CF 3) COONH 4, 100g, disodium hydrogen phosphate dodecahydrate 10.0g and perfluoroalkyl vinyl ether _{CF 3 CF 2 CF 2 (OCF} 2 CF 2 CF 2) 3 OCF = CF ₂ 32,0g was charged. After the system was sufficiently replaced with nitrogen gas, the system was evacuated and hexafluoropropylene (hereinafter referred to as HFP) at an internal pressure of 0 ° C.
Press-fit up to kg / cm ² (gauge pressure) and then use vinylidene fluoride (hereinafter referred to as VdF) to 7 kg / cm ² (gauge pressure).
Boosted to.

Then, a solution of sodium sulfite 13 mg in pure water 3 ml of pure water 3 ml and a solution of ammonium persulfate 10 mg in pure water 2 ml are sequentially added to V
The reaction was initiated by pressure injection with dF gas.

Since the pressure decreases as the polymerization reaction progresses, 6.
When the pressure drops to 5 kg / cm ² (gauge pressure), 7.0 kg / cm ² (gauge pressure) with the VdF / HFP monomer mixture (molar ratio 94/6)
While pressurizing and repeating pressure drop and pressurization, 1.2, 2.5, 3.6 and 4.6 hours after the start of polymerization, 9.0 g of each of the above perfluoroalkyl vinyl ethers was pressed in to continue the polymerization, and 5.5 hours after the start of the polymerization. Then, unreacted monomers were released to obtain an aqueous emulsion. This aqueous emulsion was coagulated by freezing, and the coagulated product was washed with water and vacuum dried to give a rubber-like polymer 8
Obtained 6.0 g.

According to ₁₉ F-NMR analysis, the composition of this polymer (hereinafter,
As well. ) VddF: HFP: [CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = C
F ₂ ] = 76.6: 10.1: 13.3 (molar ratio). The glass transition temperature of the polymer was measured by a scanning calorimeter (DSC) at a heating rate of 10 ° C.
It was found to be good at low temperature characteristics, which was −65 ° C. (peak center temperature) when measured at 1 / min (the same applies hereinafter).

Example 4 Instead of HFP, tetrafluoroethylene (hereinafter referred to as TFE) was injected so that the internal pressure was 0 kg / cm ² (gauge pressure), and the molar composition was VdF /
Using a mixed monomer with TFE = 92/8, 0.8, 1.
After 1, 1.3 and 1.5 hours, 8 g of the perfluorovinyl ether was injected under pressure, and 1.7 hours after the initiation of polymerization, an aqueous emulsion was obtained by the same procedure as in Example 3 except that unreacted monomers were released. Coagulation was performed in the same manner as in Example 3, washed with water, and vacuum dried to obtain 95.6 g of a rubber-like polymer. The composition of this copolymer is VdF: TFE: [CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = CF ₂ ] =
72.5: 13.1: 14.4 (molar ratio), and the glass transition temperature is −
It was 68 ° C.

Example 5 In a polymerization tank having an internal volume of 300 ml, 100 ml of pure water and 10 g of C ₃ F ₇ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH ₄ as an emulsifier, 1 g of disodium hydrogen phosphate 12 hydrate and perfluoro. Vinyl ether
CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = CF ₂ 5 g was charged, and after the system was sufficiently replaced with nitrogen gas, the system was evacuated and the internal pressure of the HFP was 0 kg / cm ² (15 ° C). (Gauge pressure), and VdF 7.0k
The pressure was increased to g / cm ² .

Then, a solution of 2.65 mg of sodium sulfite in 2.65 ml of pure water and a solution of 1 mg of ammonium persulfate in 1 ml of pure water were sequentially injected together with VdF gas to start the reaction. Since the pressure drops with the progress of the polymerization reaction, when the pressure drops to 6.5 kg / cm ² G, VdF gas is repressurized to 7.0 kg / cm ² G, and the polymerization is continued while repeatedly lowering and increasing the pressure. Twenty-three minutes after the initiation of polymerization, unreacted monomers were released to obtain an aqueous emulsion.

This aqueous emulsion is coagulated by freezing, and the coagulated product is washed with water,
Vacuum drying gave 7.9 g of a rubbery polymer. The composition of this polymer is VdF: HFP: [CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = CF ₂ ] =
74.2: 7.6: 18.2 (molar ratio), glass transition temperature is -65.5 ℃
Met.

Example 6 Perfluorovinyl ether CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃
An aqueous emulsion was obtained by the same procedure as in Example 5 except that the amount of OCF = CF ₂ charged was 10 g and 44 minutes after the initiation of polymerization, unreacted monomers were released. Coagulation was performed in the same manner as in Example 5, washed with water, and vacuum dried to obtain 9.6 g of a rubber-like polymer. The composition of this _{polymer, VdF: HFP: [CF 3} CF 2 CF 2 (OCF 2 CF 2 CF 2) 3 OCF = C
F ₂ ] = 72.0: 7.7: 20.3 (molar ratio), and the glass transition temperature was −70 ° C.

Example 7 CF ₃ CF ₂ C in a 100 ml pressure-resistant glass ampoule equipped with a bulb.
F ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = CF ₂ 3.0 g, 1,1,2-trichloro-1,
2,2-trifluoroethane (hereinafter referred to as R-113) 10
ml and R-113 solution of 2,4,5-trichloroperfluorohexanoyl peroxide (concentration 0.438 g / ml) 0.5 ml
, And after cooling with dry ice / methanol solution,
The system was replaced with nitrogen. Next, charge 1.2 g of VdF, and
The reaction was carried out under shaking at ℃ ± 1 ℃ for 1 hour and 30 minutes. System in gauge pressure with reaction from 2.5 kg / cm ² before the reaction 1.5 kg / cm ²
Fell to. Unreacted monomer was released, and the content was released in pure water for precipitation to separate the copolymer. Vacuum drying was performed until a constant weight was obtained to obtain 2.0 g of a copolymer. The composition of this copolymer is VdF: [CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = C
F ₂ ] = 77.0: 23.0 (molar ratio), and the glass transition temperature was −76 ° C.

Example 8 A reaction was carried out by the same procedure as in Example 7 except that 0.5 g of ethylene was charged instead of VdF and the reaction time was 1 hour and 40 minutes. The gauge pressure in the system changed from 1.5 kg / cm ² to 1.1 kg / cm ² . The weight of the copolymer after vacuum drying was 1.5 g. According to ¹ H-NMR analysis and ¹⁹ F-NMR analysis, the composition molar ratio of the copolymer was ethylene: [CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) ₃ OCF = C
F ₂ ] = 62.6: 37.4, and the glass transition temperature was −88 ° C.

Comparative Example 1 Perfluorovinyl ether CF ₃ CF ₂ CF ₂ (OCF ₂ CF ₂ CF ₂ ) _{3 of} Example 3 was replaced with OCF = CF ₂ and perfluorovinyl ether CF ₃ CF ₂ CF ₂ derived from hexafluoropropylene oxide was used. [OC (CF ₃ ) FCF ₂ ] ₃ OCF ＝ CF
₂ "(hereinafter referred to as PB ₃ VE)" 39.4g, 2.8, 4.5,
After 6.7, 7.3 and 8.2 hours, the reaction was carried out in the same manner as in Example 3 except that each 22.5 g of PB ₃ VE was injected under pressure.
After 9.3 hours, unreacted monomers were released to obtain an aqueous emulsion. Coagulation was performed by freezing this aqueous emulsion, and the coagulated product was washed with water and vacuum dried to obtain 233 g of a rubber-like polymer. The composition of this copolymer is VdF: HFP: PB ₃ VE = 75.7: 8.3:
It was 16.0 (molar ratio), and the glass transition temperature was -38.5 ° C.

Comparative Example 2 Pure water 1 and 2 g of ammonium perfluorooctanoate as an emulsifier were charged into a polymerization tank having an internal volume of 3 l, and the system was sufficiently replaced with nitrogen gas, and then hexafluoropropylene was added at 1.0 kg / cm ² at a polymerization temperature of 80 ° C. (Pressure gauge) Next, while stirring and maintaining the internal temperature at 80 ° C, add 10.0 kg / c of VdF / HFP (molar ratio 78/22) monomer mixture.
It was pressed in so that it would be m ² (gauge pressure).

The polymerization pressure drops when the reaction is initiated by press-fitting a 50 ml solution of pure water containing 2.2 g of ammonium persulfate into the polymerization tank.
When the pressure was lowered to g / cm ² (gauge pressure), the monomer mixture was used to raise the pressure to 10.0 kg / cm ² (gauge pressure), and the reaction was continued while repeating this pressure reduction and pressure increase. After 2.3 hours from the start of the reaction, unreacted monomer was released, and the polymerization tank was cooled to stop the reaction.

The product is an aqueous emulsion with a solids content of 24.3% by weight,
To this aqueous emulsion was added a 1% by weight aqueous solution of potassium alum for coagulation, washing with water and drying to obtain 331 g of a rubbery polymer. The composition of this copolymer was VdF: HFP = 78.5: 21.5 (molar ratio), and the glass transition temperature was −23.0 ° C.

The compositions, yields and glass transition temperatures (Tg) of the copolymers obtained in Examples 3 to 8 and Comparative Examples 1 and 2 are shown in the table below.

Example 9 A reaction was carried out by the same procedure as in Example 7, except that 3.6 g of TFE was charged instead of VdF and the reaction time was 3 minutes. System inside the gauge pressure was changed from 4.50kg / cm ² to 4.00 kg / cm ^2. The weight of the copolymer after vacuum drying was 2.2 g. The composition of the copolymer _{TFE: [CF 3 CF 2 CF} 2 (OCF 2 CF 2 CF 2) 3 OCF = CF 2] = 9
It was 7.8: 2.2 (molar ratio).

The melting point of the copolymer is 322 ° C. (first run melting point),
After melting once, it was 317 ° C. (second run melting point).

The melting point was measured as follows. 3 mg of powder is precisely weighed, and this is a highly sensitive DSC (differential scanning calorimeter), 910
A Differential Scanning Calorimeter (Du Pont) is used to measure the melting of crystals at the melting point. At this time, an endothermic peak due to melting is recorded on the recording paper in proportion to the amount of heat of fusion at the melting point. The powder temperature is initially set at 250 ° C to 10 ° C / min.
The temperature is raised to 80 ° C., and the melting peak temperature at this time is defined as the first run melting point. Next, the temperature is lowered to 250 ° C at 10 ° C / min, and again to 380 ° C.
Up to 10 ℃ / min, and the melting peak temperature at this time
Run melting point.

Example 10 Equipped with temperature control jacket, stirrer and baffle plate
A 3-liter stainless steel autoclave was charged with 1.45 l of deionized and deoxygenated water, 3 mg of ammonium triphosphate and 9 mg of ammonium perfluorooctanoate.
Next, the reactor was evacuated, charged with nitrogen gas, and evacuated again.
After repeating deaeration and charging operations three times in total, TFE
The same operation was repeated twice. After the last degassing, F (CF
₂ CF ₂ CF ₂ O) ₄ CF = 2.2 g of CF ₂ was charged. Then, the stirrer was started and rotated at 400 rpm to raise the temperature of the charge to 70 ° C. Next, charge TFE until the internal pressure reaches 7.5 kg / cm ² (gauge pressure), and ammonium persulfate 4.0 mg / water 50 ml
The solution was pressed with TFE to adjust the internal pressure to 8.0 kg / cm ² (gauge pressure). After a few minutes, the pressure began to drop and it was confirmed that the reaction had started. From this point on, TFE was 8.0 kg / cm ² (gauge pressure).
Continuously supply so as to keep at, and supply amount (= polymer solid content)
When the amount reached 250 g, TFE was expelled, stirring was stopped, and the reaction was terminated.

The powder was taken out, placed in an industrial mixer, water was added, and the mixture was operated for 1 minute to pulverize the powder. It was crushed for another 5 minutes while washing with changing water. The differential end obtained is 15
It was dried in a circulating air dryer at 0 ° C. for 14 hours.

The melting point of this polymer (first run melting point) is 343.9 ° C, and the melting point of the polymer once melted and cooled (second run melting point) is
It was 323.8 ° C.

The creep of the molded product of this powder was 6.4% at 24 ° C.

The creep was measured by the following procedure. 190 g of the powder was put into a cylindrical cylinder mold having a diameter of 50 mm, compression molded at 300 kg / cm ² (holding time 5 minutes), and then taken out from the mold.
Then, the temperature was raised to 365 ° C. at a heating rate of 50 ° C./hour in an air firing furnace, kept at 365 ° C. for 5 hours, and then lowered to a nitrification temperature at 50 ° C./hour. This fired product was cut into a cylindrical shape having a diameter of 11.3 mm and a height of 10 mm so that the compression direction and the height direction of the cylinder coincided with each other.
A load of 140 kg / cm ² was applied to a cylindrical sample in a constant temperature room at 24 ° C., and the height of the cylinder was measured 10 seconds and 24 hours after the start of loading. The creep was calculated by the following calculation formula.

Comparative Example 3 The reaction was performed in the same manner as in Example 9 except that F (CF ₂ CF ₂ CF ₂ O) ₄ CF = CF ₂ was not charged. Molded product creep at 24 ° C 8.
It was 6%.

The melting point is 343.9 ° C for the first run and 32 for the second run.
It was 6.6 ° C.

 ─────────────────────────────────────────────────── --Continued front page (56) References French patent 1341087 (FR, A) Issled. Stroeniya Makromekul Metdom YAMR Vysok. Razreshneyya, M .; (1983) p. 45-51 Vysokomol. Soedin. , Ser. A (1979) 21 [10] p. 2261 to 2266 Izv. Akad. Nauk SSS R, Ser. Khim. (1976) [4] p. 918-920

Claims (2)

[Claims] 1. A general formula: RfOCF ₂ CF ₂ CF _{2 n} OCF = CF ₂ (I) [wherein, Rf is a C _{1 to} C ₅ perfluoroalkyl group, and n is 2].
Is an integer of ~ 4. ] The fluoro vinyl ether shown by these. 2. A general formula: RfOCF ₂ CF ₂ CF _{2 n} OCF = CF ₂ (I) [wherein, Rf is a C ₁ -C ₅ perfluoroalkyl group, and n is 2].
Is an integer of ~ 4. ] The copolymer which has the repeating unit derived from the fluorovinyl ether shown by these, and the repeating unit derived from at least 1 sort (s) of ethylenically unsaturated compound.