JPS5950163B2 - Ethylene-tetrafluoroethylene copolymer and its production method - Google Patents

Description

Detailed Description of the Invention The present invention relates to a novel ethylene tetrafluoroethylene copolymer and a method for producing the same, and more specifically, the present invention relates to a novel ethylene tetrafluoroethylene copolymer and a method for producing the same. This invention relates to an improved new ethylene tetrafluoroethylene copolymer and a method for producing the same.

Conventionally, there is no known method for copolymerizing ethylene tetrafluoride and ethylene through the action of a polymerization initiator to produce an ethylene tetrafluoroethylene copolymer with excellent chemical resistance, heat resistance, and electrical properties. It is being

Since the copolymer has excellent properties and can be heat-melted and processed, it can be used in a wide range of materials such as various molded products, electric wire coverings, linings, and coatings. Therefore, in order to improve the high-temperature mechanical properties, especially the high-temperature tensile properties, of the ethylene tetrafluoroethylene copolymer, it is necessary to use a copolymer that has no telogen activity and at least 2
A method has been proposed in which an auxiliary amount of a copolymerizable vinyl monomer is copolymerized to provide a side chain containing 5 carbon atoms.

For example, Japanese Patent Publication No. 47-23671, U.S. Patent No. 3
See specification No. 624250, etc. According to such a method, the disadvantage that the wire coating of the ethylene tetrafluoroethylene copolymer becomes brittle at high temperatures and cracks under low stress can be overcome. However, although the conventionally proposed vinyl monomers with bulky side chains can provide advantageous results for improving high-temperature tensile properties, various disadvantages are recognized for industrial implementation. .

For example, CF2=CF-C2F5, CF2=CF-C4F
When copolymerizing ethylene and tetrafluoroethylene by adding a perfluoroolefin represented by the general formula CF2=CF-RF such as 9, the copolymerization reaction rate is significantly reduced. In addition, the general formula CF2=CF-0Rf or CF2=CF-0 represented by CF2=CF-0C3F7
When copolymerizing ethylene and tetrafluoroethylene by adding a vinyl ether such as CH2RF, CF2=CF-0R, the tensile creep properties of the resulting copolymer deteriorate, for example, at 175°C, 30k9/CWL. In a tensile creep test under load, an ethylene tetrafluoroethylene copolymer exhibits an initial deformation of about 2 to 3%, but when vinyl ether is introduced, the initial deformation is 7% or more. Furthermore,
Hydrofluoroolefins, vinyl esters, etc. such as CF2=CF-CH2-C(CF3)20H or CH2=CH-OC-CH3 reduce the heat resistance of the resulting copolymer, such as elongation at room temperature. Due to the introduction of such side chains, the ethylene tetrafluoroethylene copolymer exhibits heat resistance of 200 hours or more in a test (heating temperature 230°C) that measures the heat aging time at which the temperature decreases to 50% of the initial value. Examples of disadvantages include a decrease in heat resistance of 80 to 100 hours or less. The present inventor has conducted various research studies in order to provide a means for improving the high-temperature tensile properties of ethylene tetrafluoroethylene copolymers without impairing as much as possible the original excellent physical properties. As a result, we obtained the following interesting findings.

That is, when copolymerizing a small amount of specific perfluoroalkylvinyl monomers such as perfluorobutyl ethylene and perfluorohexyl ethylene with tetrafluoroethylene and ethylene, without impairing the tensile creep or heat aging resistance, It has been discovered that the high temperature tensile properties of ethylene tetrafluoroethylene copolymers can be advantageously improved. Thus, the present invention has been completed based on the above-mentioned new findings, and is based on the above-mentioned novel findings.
The content molar ratio of ethylene is 40/60 to 60/40, and the content of a perfluoroalkylvinyl monomer represented by the general formula CH2=CH-CnF2n+1 (where n in the formula is an integer of 2 to 10) The amount is between 0.1 and 10 mol, and the volume flow rate as defined below is between 10 and 500.
The object of the present invention is to provide a novel ethylene tetrafluoroethylene copolymer, which is characterized in that:

The term "volume flow rate" used herein is defined as follows and serves as a measure of molecular weight.

That is, using a Koka type flow tester, a 1θ sample is extruded from a nozzle with a nozzle diameter of 1 mm and a land of 2 mm under a predetermined temperature and a predetermined load of 30 kg/Cd, and the melt extruded per unit time. The value expressed by the volume of the sample is
Defined as "volume flow rate", its unit is 1/second.Here, the predetermined temperature refers to the temperature range (flow start temperature and thermal decomposition temperature) in which a specific ethylene tetrafluoroethylene copolymer can be molded. 300° C. is selected for the particular copolymer of the present invention.
Further, the present invention provides the general formula CH2=CH-CnF2n+1 (
However, by adding a small amount of perfluoroalkylvinyl monomer (n in the formula is an integer from 2 to 10), the reaction molar ratio of tetrafluoroethylene/ethylene is substantially 40/60 or more. ethylene and tetrafluoroethylene are copolymerized under the action of a polymerization initiation source while maintaining the perfluoroalkylvinyl monomer content in the range of 0.1 to 10 moles. The present invention also provides a new method for producing an ethylene tetrafluoroethylene copolymer.

The ethylene tetrafluoroethylene copolymer obtained by the present invention has advantageously improved tensile strength and ultimate elongation at high temperatures without substantially impairing its original excellent physical properties as described above. ing.

Therefore, the copolymer wire coating according to the invention does not become brittle at high temperatures or crack at low stresses. or,
Characteristically, despite the introduction of bulky side chains, the initial deformation in the tensile creep test is not excessive, and the elongation retention time is over 200 hours in the heat aging test. Furthermore, the copolymers according to the invention show excellent growth in environmental stress cracking tests, for example, without any cracking at 120° C. in a 60% nitric acid atmosphere or in ethylene diamine. It should be noted that conventional ethylene tetrafluoroethylene copolymers could not give satisfactory results in environmental stress cracking tests, and even with the introduction of the previously proposed bulky side chains, 60% nitric acid At 120°C in a polar solvent such as nitrobenzene, dimethyl sulfoxide or dimethyl formamide as well as in an atmosphere or ethylene diamine.
Cracks occur. Therefore, the novel ethylene tetrafluoroethylene copolymer of the present invention has a volume flow rate of 10 to 50
0 md/sec, preferably 20-300 m71i/sec. Because it is within such a volumetric flow rate range, it is possible to perform heat melt molding such as extrusion molding and injection molding, and it is also easy to bake in powder coating, dispersion coating, etc. Further, the new copolymer suitable for the present invention has a flow initiation temperature of 240'C or higher, preferably 250 to 280C, and a thermal decomposition onset temperature of 310C or higher, preferably 33
The temperature is 0 to 370°C. Therefore, as mentioned above, it is easy to process by hot melt molding, has excellent heat resistance, and has improved high-temperature tensile properties while maintaining these properties. In the present invention, in order to produce a suitable new copolymer, the reaction molar ratio of tetrafluoroethylene/ethylene is usually 2.35 or more, preferably 3 or more.

That is, in a preferred embodiment, the copolymerization is carried out so that the ratio of tetrafluoroethylene monomer to ethylene monomer in the copolymerization reaction system is maintained within the above range. For example, the charging molar ratio of tetrafluoroethylene/ethylene is selected from the above range,
For example, the copolymerization reaction is carried out while replenishing the amount consumed as the copolymerization reaction progresses. Therefore, in the method of the present invention, the charging molar ratio of tetrafluoroethylene/ethylene is 70/30 to 90/10, preferably 75/25 to 8.
5/15, and the molar ratio of tetrafluoroethylene/ethylene is 40/60 to 60/40 during the copolymerization reaction.
It is desirable to carry out the copolymerization reaction while replenishing the monomer mixture, preferably from 45/55 to 55/45.
Thus, the tetrafluoroethylene content is 40-60 mol%, especially 45-55 mol%? An ethylene tetrafluoroethylene copolymer is obtained. In the present invention, a particular perfluoroalkylvinyl monomer has the general formula CH2=CH-Cn
It is expressed as F2n+1.

n is selected from an integer of 2 to 10, preferably n=
3 to 8 are selected. Perfluoroalkyl group (-Cn
F2n+1) may be linear or branched. Particularly preferred perfluoroalkyl groups are -C4F9 and -C6
It is Fl3. If n is too large, not only will there be an increased tendency to impair the original physical properties of the ethylene tetrafluoroethylene copolymer, but it will also be disadvantageous in terms of a decrease in the copolymerization reaction rate. Furthermore, when n is 1, the effect of introducing a small amount is reduced, making it difficult to achieve a satisfactory improvement. Furthermore, n=
Even in the case of 2 to 10, ordinary non-perfluorinated alkyl groups are disadvantageous compared to the excellent heat resistance of the ethylene tetrafluoroethylene copolymer. CH2=CH-CnF2n+1 (hereinafter, CH
2=CH-Rf) is produced by various means and is easily available.

Usually, it can be easily obtained by subjecting a perfluoroalkyl halide to ethylene and subjecting the addition reaction product to a dehydrohalogenation reaction. That is,
RfCH2CH2 is formed by addition reaction between RfX and ethylene.
By generating X and subjecting the RfCH2CH2X to a de-HX reaction, a perfluoroalkylvinyl monomer CH2=CH-Rf can be synthesized. Note that X is preferably a bromine atom or an iodine atom, and a chlorine atom is also possible. The addition reaction proceeds under heating, in the presence of a free radical catalyst, or under irradiation with ultraviolet light or radiation. For example, HaszeIdine et al.
．． S0c. , 2856 (1949); 3041 (195
0)) method of Park et al. (J. Org. Olem.
, 23, 1166 (1958)) and the method described in U.S. Pat. No. 3,145,222 (1964). Perfluoroalkylvinyl monomers can be converted into monomers. or,
Certain types of reactions using the above-mentioned RfCH2CH2X as raw materials (for example, Japanese Patent Publication No. 39-18112,
8-103504, etc.) may also be used as the specific perfluoroalkylvinyl monomer in the present invention.

In the copolymerization reaction of the method of the present invention, the amount of the specific perfluoroalkylvinyl monomer added is preferably as small as possible, usually 0.1 to 10% on the basis of all monomers.
Selected from a range of mol%.

If the amount added is too small, the effect of improving the high-temperature mechanical properties of the resulting copolymer will not be observed, and if it is too large, the copolymerization reaction rate will be unsatisfactory for industrial purposes. This is disadvantageous to the originally excellent physical properties of the ethylene tetrafluoroethylene copolymer. Therefore, in order to obtain an industrially advantageous and excellent copolymer, the amount of the specific perfluoroalkylvinyl monomer added should be 0.
It is desirable to set it to about 3 to 5 mol%. Regarding the specific perfluoroalkyl vinyl monomer, it is preferable to carry out the copolymerization reaction while maintaining the above ratio, and it is usually preferable to carry out the copolymerization reaction while replenishing the amount consumed as the copolymerization reaction progresses. be.

In the present invention, a small amount of a specific perfluoroalkylvinyl monomer is copolymerized and contained in the produced copolymer, usually about 0.1 to 10 mol%, particularly 0.3 to 5 mol%.
A content of about mol% is desirable. Therefore, during the course of the copolymerization reaction, a specific perfluoroalkylvinyl monomer is replenished at a concentration of 0.1 to 10 mol%, preferably 0.3 to 5 mol%, along with tetrafluoroethylene and ethylene. is desirable. Thus, from 0.1 to 10 mol % of the specific perfluoroalkyl vinyl monomer, preferably 0.3
An ethylene monotetrafluoroethylene copolymer copolymerized with ~5 mol% is obtained. In addition, specific perfluoroalkyl in the produced copolymer. The content of rubinyl monomer is calculated from the difference between the amount of each monomer introduced into the polymerization tank and the amount of each cenomer recovered after completion of polymerization. If the content of the specific perfluoroalkylvinyl monomer in the resulting copolymer is too small, no improvement in high-temperature mechanical properties will be observed, but if it is too large, the ethylene tetrafluoroethylene copolymer Tensile creep of coalescence, heat aging resistance, etc. deteriorate, resulting in an excessively soft product.

The ethylene tetrafluoroethylene copolymer obtained by the present invention has the tensile strength and ultimate elongation at a high temperature, for example, 200°C, of an ethylene tetrafluoroethylene copolymer containing no perfluoroalkyl vinyl monomer are each~
20kg/Clil, ~40%, respectively, 30k9/Cit or more, especially 40-80kg/1, 2
00% or more, especially 400 to 600%, and eliminates the problem that the wire coating becomes brittle at high temperatures and cracks at low stress. On the other hand, at 175℃, 30kg/(-J
MoVF tensile creep test, initial deformation in test is 10%
Below, especially when the content of the specific perfluoroalkyl vinyl monomer is about 0.3 to 1.0%, it is 5% or less, and the heat aging test at 230°C is 200 hours or more. The properties of the ethylene tetrafluoroethylene copolymer, which does not contain an alkyl vinyl monomer, are not deteriorated. The copolymerization reaction in the present invention can be carried out using or without the use of an inert organic solvent or an aqueous medium under the action of a polymerization initiation source such as a peroxy compound, an azo compound, ultraviolet light, or ionizing radiation. This can be done by such means as

Moreover, various polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, and gas phase polymerization can be employed as the polymerization method. According to the research of the present inventor, a solvent consisting of a fluorinated or fluorinated chlorinated saturated hydrocarbon known as a so-called fluorocarbon solvent, preferably having a carbon number of 1, is used as the copolymerization reaction medium. It is advantageous to use ~4, especially 1 to 2, in terms of producing an ethylene tetrafluoroethylene copolymer with excellent heat resistance, moldability, chemical resistance, and other properties. It has been recognized that controlling the reaction conditions and maintaining the copolymerization reaction rate can also provide advantageous results for industrial implementation. Examples of fucan solvents include dichlorodifluoromethane, trichloromonofluoromethane, dichloromonofluoromethane, monochlorodifluoromethane, chlorotrifluoromethane, fluoroform, tetrafluoroethane, trichlorotrifluoroethane, dichlorotetrafluoroethane,
Examples include hexafluoroethane, fluorochloropropane, perfluoropropane, fluorocyclobutane, perfluorocyclobutane, etc., and these may be used alone or in a mixture of two or more. According to the research of the present inventor, dichlorodifluoromethane, trichloromonofluoromethane, trichlorotrifluoroethane,
A solvent consisting of a fluorinated or fluorinated chlorinated saturated hydrocarbon that does not contain a hydrogen atom in its molecule, such as dichlorotetrafluoroethane or perfluorocyclobutane, preferably having 1 to 4 carbon atoms, especially 1 to 2 carbon atoms. It has been recognized that it is particularly desirable when using such materials to increase the molecular weight of the resulting copolymer, among other things. In the method of the present invention, when a fluorocarbon solvent is used, the amount used is not particularly limited, but usually tetrafluoroethylene, ethylene,
0.05 to 20 mol of solvent, especially 1 mol of the monomer mixture of the specific perfluoroalkyl vinyl monomer
~10 moles are employed.

Although it is possible to carry out the copolymerization reaction even if the amount of solvent used is less than 0.05 mole per mole of monomer, it is necessary to increase the copolymerization reaction rate using industrially advantageous operations and conditions. It is advantageous to use 1 mol or more. Although it is possible to use more than 20 moles of the solvent, it is advantageous to use 10 moles or less mainly for economical reasons such as recovering the solvent after the reaction. Further, in the method of the present invention, it is also possible to use a mixture of the fluorocarbon solvent with another organic solvent or an aqueous medium. For example, it is possible to employ a mixed reaction medium of chlorofluorocarbon solvent and water, and by such means, good results can be achieved in terms of stirring of the copolymerization reaction system, ease of removing reaction heat, etc. In the method of the present invention, the copolymerization reaction conditions can be varied depending on the polymerization initiation source, reaction medium, etc., but when using a fluorocarbon solvent, the reaction temperature is usually about -500C to +150C, which is industrially acceptable. be advantageously adopted. An appropriate reaction temperature is selected depending on the type and amount of solvent used, the molar ratio of monomers added, the amount of specific perfluoroalkylvinyl monomer added, the type of polymerization initiation source, etc. At high temperatures, the reaction pressure becomes excessive, and at too low temperatures, the copolymerization reaction rate falls below an industrially satisfactory level.
It is desirable to adopt the above range. The reaction pressure is normal pressure or slightly increased pressure, and is usually 2 to 50k.
9/CTl gauge is adopted, and higher pressure or lower pressure may also be adopted as appropriate. In the method of the present invention, various polymerization initiation sources can be appropriately employed depending on the polymerization method, and there is no particular reason to limit the source.

However, when using fluorocarbon-based solvents, cobalt-
It is desirable to employ ionizing radiation such as gamma line from cesium-60 or cesium-137, or an oil-soluble radical polymerization initiation source such as a peroxine compound or an azo compound. for example,
Ionizing radiation can be used at a dose rate of 10 to 106 rats/hour, and peroxy compounds include organic peroxides such as benzoyl peroxide and lauroyl peroxide, and peroxides such as t-butylperoxyisobutyrate. Esters, diisopropyl peroxydicarbonate, etc. are generally used, and as the azo compound, a radical initiator such as azobisisobutyronitrile is generally used. The amount of the radical initiator used must be selected depending on the polymerization conditions employed, that is, the amount of specific perfluoroalkyl vinyl monomer added, the medium used, the polymerization temperature, etc., but it is usually 0.0001-2 for mass
Concentrations on the order of % by weight may be employed. In order to obtain a suitable ethylene tetrafluoroethylene copolymer in the present invention, a fluorocarbon solvent is used as a polymerization initiation source (general formula)
11R-C-
It is desirable to use a peroxy ester type radical initiator represented by the formula 0-0-R' (in which R and R' are aliphatic alkyl groups).

It is advantageous in terms of copolymerization reaction rate, various physical properties of the produced copolymer, copolymerization reaction operation and conditions, etc. R and R' are aliphatic alkyl groups, and the number of carbon atoms thereof is not particularly limited, but due to the copolymerization reaction temperature, both R and R' have 3 to 1 carbon atoms.
It is desirable to have about three alkyl groups. for example,
t-butyl peroxyisobutyrate, t-butyl peroxy acetate, t-butyl peroxy pivalate,
t-butylperoxy-2-ethylhexanoate, t-
Examples include butyl peroxylaurate. The amount of peroxyester type radical initiator used is:
A concentration of about 0.001 part by weight or more based on 100 parts by weight of the total monomers is sufficient.

Preferably, the radical initiator concentration in the fluorocarbon solvent is
Approximately 0.005 to 5 parts by weight is used per 100 parts by weight of the total monomers. The fluorocarbon solvent is used in an amount of about 1 to 10 moles, particularly about 1.5 to 5 moles, per mole of the monomer mixture. Further, the copolymerization reaction temperature may normally be about 30 to 120°C, but it is desirable to select the optimum temperature in consideration of the half-life of the peroxyester type radical initiator used. For example, the temperature is 50 to 80°C for t-butylperoxyisobutyrate, and 40 to 60°C for t-butylperoxypivalate.
By employing such a reaction temperature, it is possible to obtain a new copolymer in good yield without requiring a long time. In addition, when using a fluorocarbon solvent in the method of the present invention,
After the copolymerization reaction is completed, the solvent can be easily separated from the produced copolymer together with unreacted monomers.

Furthermore, since excessive reaction pressures such as those in copolymerization reactions carried out in an aqueous medium can be suppressed, it is possible to safely produce ethylene-tetrafluoroethylene copolymers having excellent physical properties without employing high temperatures and high pressures. Moreover, in this case, the copolymerization reaction rate is industrially satisfactory as described above. This description is not intended to limit the invention in any way. Next, examples of the present invention will be described in more detail, but it goes without saying that the present invention is not limited by such explanations.

In addition, in the following examples, the physical properties of the copolymer were measured by the following method. [Tensile strength and elongation at high temperatures] Measured using a JISI tamper according to ASTM D-638.

・Measurement conditions: 200℃, 2007! Tm/min (Tensile speed) [Tensile creep] Measured using JISI tampel according to ASTM D-638.

Measurement conditions: 175°C, 30k9/d [Environmental stress crack] According to ASTM D-1693, 33mwL x 13mm x
Put a notch in a 1mm thick test piece and bend it.
Immerse it in chemicals and observe whether cracks occur.

Example 1 3.46 kg of trichlorocamofluoromethane, 6.52 kg of trichlorotrifluoroethane, and 2.38 g of t-butylperoxyisobutyrate were charged into an autoclave having an internal volume of 1011 kg, and then 12 g of tetrafluoroethylene was charged.
269, ethylene 829, and perfluorobutylethylene (CH2=CH-C4F9) 261.

While sufficiently stirring this mixture, the reaction temperature was maintained at 65° C. to carry out the copolymerization reaction. During the copolymerization reaction, a mixed gas of tetrafluoroethylene/ethylene/perfluorobutylethylene with a molar ratio of 53/46.3/0.7 was introduced into the system, and the polymerization pressure was increased to 15.0 kg/(-J mole). After 5 hours, a white copolymer of 4609 was obtained.

The copolymer has C2F4/C2H4/CH2=C
The molar ratio of HC4F9 is 53/46.3/0.
7, flow start temperature 267°C, thermal decomposition start temperature 36
It was 0℃. The volumetric flow rate of the copolymer is 50-/sec;
The melting point was 267°C. Tensile strength at 200°C,
The ultimate elongation was 55 kg/d and 610%, respectively, and when coated on wire, the drawback of cracking at high temperatures and low stress was eliminated.

Further, the initial deformation due to tensile creep at 175°C and 30 kg/Cd was 3.2%, and the heat aging time at 230°C was over 200 hours. All ten test samples did not crack in an environmental stress cracking test in 60% nitric acid.

Example 2 36.5 g perfluorohexylethylene (CH2=
The reaction was carried out in exactly the same manner as in Example 1, except that CHC6Fl3) was charged and the mixed gas introduced into the system was changed to tetrafluoroethylene/ethylene/perfluorohexylethylene-53/46.3/0.7. .

After 5.4 hours, a white copolymer of 5079 was obtained. The copolymer is C2F4/C2H4/CH2=CHC6Fl3
The molar ratio of these was 53/46.3/0.7, the flow start temperature was 267°C, and the thermal decomposition start temperature was 360°C.

The volumetric flow rate of the copolymer was 60ml/sec and the melting point was 267.
It was warm at ℃. The tensile strength and ultimate elongation at 200°C are 52 kg/(1-J mo Vf, 620%, respectively, and the mechanical properties at high temperatures are sufficiently improved. At 175°C, 30
The initial deformation of tensile creep at 1<fl/CTil is 3.3%, and the heat aging time at 230°C is 20
It was over 0 hours. Example 3 Perfluorobutylethylene (CH2CHC4F
9) Example 1 except that 19.2 g was charged and the composition of the mixed gas introduced during the reaction was tetrafluoroethylene/ethylene/perfluorobutyl ethylene = 53/46.5/0.5.
The reaction was carried out in exactly the same manner.

After 4.2 hours, a white copolymer of 4709 was obtained. The copolymer had a molar ratio of C2F4/C2H4/CH2CHC4F9 of 53/46.5/0.5, a flow start temperature of 272°C, and a thermal decomposition start temperature of 360°C. The copolymer had a volumetric flow rate of 47 md/sec and a melting point of 269°C. The tensile strength and ultimate elongation at 200℃ are 6 each.
0 kg/CTIl560%, and has sufficient high temperature mechanical properties. The initial tensile creep deformation at 175°C and 30 kg/ml was 3.0%, and the heat aging time at 230°C was 200 hours or more. Example 4 In a 101 autoclave, 2.56k9 of trichloromonofluoromethane and 4.4k9 of trichlorotrifluoroethane were added.
4 kg and t-butyl peroxyisobutyrate 2.2
59, then 1025 g of tetrafluoroethylene, 4.09 g of ethylene, and 46.9 g of perfluorobutyl ethylene.
Prepare 9.

Claims (1)

[Claims] 1. The molar ratio of tetrafluoroethylene/ethylene is 40/6.
0 to 60/40, and the general formula CH_2=CH-C_n
The content of the perfluoroalkyl vinyl monomer represented by F_2n+_1 (where n in the formula is an integer of 2 to 10) is 0.1 to 10 mol%, and the volume flow rate defined in the text is 10 to 500 mm. 3/sec. 2 Perfluoroalkyl vinyl monomer is CH_2=
The ethylene tetrafluoroethylene copolymer according to claim 1, which is CH-C_4F_9. 3 Perfluoroalkylvinyl monomer is CH_2=
The ethylene-tetrafluoroethylene copolymer according to claim 1, which is CH-C_6F_1_3. 4 Content of perfluoroalkyl vinyl monomer is 0
．． The ethylene-tetrafluoroethylene copolymer according to claim 1, which has a content of 3 to 5 mol%. 5 The molar ratio of tetrafluoroethylene/ethylene is 45/5
The ethylene-tetrafluoroethylene copolymer according to claim 1, which has a molecular weight of 5 to 55/45. 6 The molar ratio of tetrafluoroethylene/ethylene is 50/5
0 or more, the ethylene-tetrafluoroethylene copolymer according to claim 1 or 5. 7. The ethylene-tetrafluoroethylene copolymer according to claim 1, which has a volumetric flow rate of 20 to 300 mm^3/sec. 8. The ethylene-tetrafluoroethylene copolymer according to claim 1, which has a flow initiation temperature of 240°C or higher. 9. The ethylene-tetrafluoroethylene copolymer according to claim 1, which has a thermal decomposition initiation temperature of 310°C or higher. 10. The ethylene-tetrafluoroethylene copolymer according to claim 1, which has a tensile strength of 30 kg/cm^2 or more at 200°C and an ultimate elongation of 200% or more. 11. The ethylene-tetrafluoroethylene copolymer according to claim 1, which has an initial deformation of 10% or less in a tensile creep test at 175°C and 30 kg/cm^2. 12. The ethylene-tetrafluoroethylene copolymer according to claim 1 or 11, which has an initial deformation of 5% or less in a tensile creep test at 175°C and 30 kg/cm^2. 13 General formula CH_2=CH-C_nF_2_n_+_
1 (however, n in the formula is an integer of 2 to 10) to which a small amount of perfluoroalkylvinyl monomer is added, the reaction molar ratio of tetrafluoroethylene/ethylene is substantially 40/60 or more. ethylene-tetrafluoride having a perfluoroalkylvinyl monomer content of 0.1 to 10 mol%, characterized in that ethylene and tetrafluoroethylene are copolymerized under the action of a polymerization initiation source while maintaining Production method of ethylene copolymer. 14. The method for producing an ethylene-tetrafluoroethylene copolymer according to claim 13, which is carried out by maintaining the reaction molar ratio of tetrafluoroethylene/ethylene to substantially 70/30 or more. 15. A method for producing an ethylene-tetrafluoroethylene copolymer according to claim 13 or 14, which is carried out by maintaining the reaction molar ratio of tetrafluoroethylene/ethylene to substantially 75/25 or more. . 16 Tetrafluoroethylene/ethylene charging molar ratio is 70/3
Selected from the range of 0 to 90/10, and the molar ratio of tetrafluoroethylene/ethylene is 40/60 to 60 during the progress of the copolymerization reaction.
15. The method for producing an ethylene-tetrafluoroethylene copolymer according to claim 14, which is carried out while replenishing a monomer mixture of 1/40. 17 The charging molar ratio of tetrafluoroethylene/ethylene was 75/
25 to 85/15, and the tetrafluoroethylene/ethylene molar ratio is 45/55 to 55 during the progress of the copolymerization reaction.
16. The method for producing an ethylene-tetrafluoroethylene copolymer according to claim 15, which is carried out while replenishing a monomer mixture of /45. 18. The method for producing an ethylene-tetrafluoroethylene copolymer according to claim 13, wherein a perfluoroalkyl vinyl monomer having a perfluoroalkyl group having 3 to 8 carbon atoms is used. 19 CH as perfluoroalkylvinyl monomer
A method for producing an ethylene-tetrafluoroethylene copolymer according to claim 18, using _2=CH-C_4F_9. 20 CH as perfluoroalkylvinyl monomer
A method for producing an ethylene-tetrafluoroethylene copolymer according to claim 18, using _2=CH-C_6F_1_3. 21 Claims 13, 18, 19, or 20 in which the amount of perfluoroalkyl vinyl monomer added is selected from the range of 0.1 to 10 mol% based on the total monomers. A method for producing an ethylene-tetrafluoroethylene copolymer as described in 1. 22 Ethylene-tetrafluoroethylene according to claim 13 or 21, wherein the amount of perfluoroalkyl vinyl monomer added is selected from the range of 0.3 to 5 mol % based on the total monomers. Process for producing copolymers. 23. A method for producing an ethylene-tetrafluoroethylene copolymer according to claim 13, which is carried out with the addition of a fluorinated or fluorinated chlorinated saturated hydrocarbon solvent. 24 Ethylene-tetrafluorination according to claim 13 or 23, which is carried out with the addition of a fluorinated or fluorinated chlorinated saturated hydrocarbon solvent that does not contain a hydrogen atom in its molecule. Production method of ethylene copolymer. 25 0.05 to 20% solvent per mole of monomer mixture
25. The method for producing an ethylene-tetrafluoroethylene copolymer according to claim 23 or 24, which is carried out in the presence of moles. 26. A method for producing an ethylene-tetrafluoroethylene copolymer according to claim 23 or 24, which is carried out at a reaction temperature of -50°C + 150°C. 27 Reaction pressure 2-50 kg/cm^2. A method for producing an ethylene-tetrafluoroethylene copolymer according to claim 23 or 24, which is carried out using a gauge. 28. A method for producing an ethylene-tetrafluoroethylene copolymer according to claim 13, 23, or 24, which uses ionizing radiation as a polymerization initiation source. 29. A method for producing an ethylene-tetrafluoroethylene copolymer according to claim 13, 23, or 24, which uses a radical initiator as a polymerization initiation source. 30. A method for producing an ethylene tetrafluoroethylene copolymer according to claim 29, which uses a peroxyester type radical initiator. 31 0.001 to 2% by weight based on the total monomer charged
A method for producing an ethylene-tetrafluoroethylene-tetrafluoroethylene copolymer according to claim 29 or 30, which uses a radical initiator of 32 With the addition of a solvent consisting of a fluorinated or fluorinated chlorinated hydrocarbon, the general formula ▲mathematical formula, chemical formula, table, etc. can be used as a polymerization initiation source▼(However, R and R in the formula
14. The method for producing an ethylene-tetrafluoroethylene copolymer according to claim 13, which is carried out using a peroxy ester type radical initiator (' is an aliphatic alkyl group). 33. The method for producing an ethylene-tetrafluoroethylene copolymer according to claim 32, which is carried out at a reaction temperature of 30 to 120°C. 34. The method for producing an ethylene-tetrafluoroethylene copolymer according to claim 32, which is carried out in the presence of 1 to 10 moles of solvent per mole of the monomer mixture.