JP3048347B2 - Fluorine-containing random copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel fluorine-containing random copolymer.

[0002]

2. Description of the Related Art Conventionally, tetrafluoroethylene (hereinafter abbreviated simply as TFE) has been used as a fluorine-containing resin having excellent chemical resistance, heat resistance, melt moldability and electrical properties. BACKGROUND ART Copolymers (hereinafter abbreviated as PFA) of fluoropropyl vinyl ether (hereinafter abbreviated as PPVE) have been produced, and are used in a wide range of industrial fields because of their excellent properties.

[0003] However, the copolymer has the following problems. First, the comonomer PPVE
At present, it is produced by reacting a dimer of hexafluoropropene oxide with an alkali metal salt and then thermally decomposing it.
The overall VE yield is low. Further PPVE
Is poor in polymerizability with TFE, so the utilization of PPVE, that is, the ratio of the amount of PPVE bonded and present in the copolymer to the amount of PPVE charged during polymerization is extremely low. For example, according to JP-B-48-2223, the utilization rate of PPVE is only a few to 30%. For this reason, a method and a process for collecting expensive PPVE are required. Furthermore, there is also a loss of PPVE in this step, making the copolymer expensive.

On the other hand, British Patent No. 812116 discloses a homopolymer of a monomer represented by CF ₂ ＣＦCF-OR (where R is an alkyl radical or a fluorinated alkyl radical) and a copolymer with TFE. It is shown. However, the CF ₂ described in this British Patent
= The copolymerization method of CF-OR and TFE is an emulsion polymerization method using water as a medium. The inventors have confirmed that when the copolymerization of CF ₂ ＣＦCF—OR and TFE is carried out by emulsion polymerization, the obtained copolymer is CF ₂ ＣＦCF
Despite the introduction of about 6 mol% of monomer units based on -OR, the same melting point as that of the homopolymer of TFE (32
7 ° C.), and the tensile strength of a sheet obtained from this copolymer was as low as 200 kg / cm ² .

Accordingly, an object of the present invention is to provide a novel fluorine-containing copolymer having a high utilization rate of a monomer and having characteristics such as chemical resistance, mechanical strength and heat resistance.

[0006]

DISCLOSURE OF THE INVENTION In view of the above-mentioned problems, the present inventors have considered that a fluorine-containing vinyl ether compound having good copolymerizability in a wide composition with a fluorine-containing olefin, particularly TFE, and having a high utilization factor. A large number of compounds were synthesized in order to search for and the copolymerization experiment was repeated. As a result, the fluorine-containing vinyl ether having a specific structure had good copolymerizability with TFE, and most of the fluorine-containing vinyl ether was copolymerized in a short time and in one polymerization. Polymerization was found. And the obtained copolymer is excellent in chemical resistance, mechanical strength and heat resistance,
In addition, they found that they were also excellent in melt moldability,
The present invention has been completed.

That is, the present invention relates to (1) (A) a compound represented by the general formula [I]:

[0008]

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90 to 99.5 mol% of a monomer unit represented by the following formula (B):

[0010]

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(Where X is a hydrogen atom or a halogen atom, and n is an integer of 1 or more) consisting of 10 to 0.5 mol% of a monomer unit represented by the following formula: Is 10 ² to 10 ⁷ poise, and has a melting point of 290 to 3
It is a fluorine-containing random copolymer characterized by having a temperature of 25 ° C.

In the monomer unit represented by the general formula [II], X may be a hydrogen atom or a halogen atom, and each halogen atom of fluorine, chlorine, bromine and iodine is employed. Further, n may be an integer of 1 or more, but n is 1 to 12, and 1 to 12, for ease of production of the fluorine-containing random copolymer of the present invention, that is, for ease of polymerization. 8
Is preferably within the range.

The composition of each of the monomer units represented by the general formulas [I] and [II] is such that the content of the monomer unit represented by the general formula [I] is 60 to 99.5 mol%. Although it can be polymerized, it is 10 to 9 in the present invention for the reason described later.
9.5 mol%, and preferably 90 to 90 mol% in order to improve the melt moldability of the obtained fluorine-containing random copolymer.
99 mol%. Similarly, the monomer unit represented by the general formula [II] can be copolymerized in the range of 0.5 to 40 mol%, but in the present invention, it is 0.5 to 10 mol%, Preferably it is 1 to 10 mol%. The general formula [I
When the monomer unit represented by I) is less than 0.5 mol%, the melt moldability is poor. On the other hand, when it exceeds 40 mol%, a solid copolymer is not obtained, and the oil is in the form of an oil. Not preferred.

That is, the monomer represented by the general formula [I] and the monomer represented by the general formula [II] are combined with the monomer represented by the general formula [II] in an amount of 0.5 to 40 mol%. When random copolymerization is carried out, there is a concern that the copolymer contains a hydrogen atom in the molecule, so that the chemical resistance is inferior, but in fact, the chemical resistance is surprisingly very good, and PPVE and It is comparable to PFA and other perfluoro resins commercially available in copolymers of TEF. For this reason, films, tubes, packing materials, lining materials,
It can be used as other molded products. It also has excellent electrical properties and can be used in the electrical and electronics fields for connectors, substrate materials, insulating materials and others.

Further, the monomer unit based on the fluorinated vinyl ether represented by the general formula [II] of the present invention is used in an amount of 0.1.
Copolymers containing 5 to 10 mol% are conventional PPVE and T
It is a molding material that is more excellent in mechanical properties such as tensile strength than PFA, which is a copolymer with FE, and can be used as a molded product in a wide range of fields.

In the fluorine-containing random copolymer of the present invention, the monomer units represented by the above general formulas [I] and [II] are randomly arranged.

Since the fluorine-containing random copolymer of the present invention is insoluble in various solvents, its molecular weight cannot be determined by ordinary means. However, since the melt viscosity of the fluorine-containing random copolymer of the present invention depends on the content and molecular weight of the monomer unit represented by the general formula [II], the molecular weight can be estimated from the melt viscosity.

The melt viscosity of the fluorine-containing random copolymer of the present invention varies depending on the composition of each monomer unit represented by the general formulas [I] and [II]. For example, when the monomer unit represented by the general formula [II] is 0.5 mol% or more and 10 mol% or more.
When it is in the range of not more than 10 mol%, the melt viscosity measured at 350 ° C. is in the range of 10 ² to 10 ⁷ poise. The measured melt viscosity is in the range of 10 ² to 10 ⁷ poise.

In the fluorine-containing random copolymer of the present invention, those having a monomer unit represented by the general formula [II] in the range of 0.5 mol% to 10 mol% have a melting point of 290 to 90 mol%.
325 ° C, preferably in the range of 290-320 ° C.
In addition, the fluorine-containing random copolymer of the present invention having the above composition has a thermal decomposition temperature in the range of 370 to 410 ° C.

The monomer unit represented by the general formula [II] is 1
Those having a range of more than 0 mol% and 40 mol% or less do not show a definite melting point, but have a glass transition temperature of -10 ° C or lower, generally -10 to -100 ° C. Further, the fluorine-containing random copolymer of the present invention having the above composition has good transmittance of visible to ultraviolet light, and generally has an absorbance of light of 250 nm of 0.1.
4 or less.

The fluorine-containing random copolymer of the present invention has an infrared absorption spectrum (hereinafter referred to as IR) of 2
990 cm ^-1 -CH near ₂ - -CF group, and 1200cm around ^-1 - group, 900 cm -CH ₂ OCF ₂ around ^-1
_It has an absorption band based on a ₂ -group, and by confirming and quantifying these absorption bands, it is a fluorine-containing random copolymer of the present invention and a fluorine-containing random copolymer represented by the general formula [II]. The content of monomer units based on vinyl ether can be determined.

FIG. 3 shows the IR of the film (thickness: 50 μm) of the fluorine-containing random copolymer obtained in Example 1.

Further, the structure of the side chain can be confirmed from the fragment generated by decomposition of the side chain by pyrolysis gas chromatography / mass spectrometry (hereinafter referred to as Py-GC / MS). For example, for the fluorine-containing random copolymer obtained in Example 1, a fragment derived from a pentafluoropropyl group can be detected from Py-GC / MS.

The fluorine-containing random copolymer of the present invention may be produced by any method, but is particularly preferably produced by the following method.

That is, tetrafluoroethylene and the general formula [III] CF ₂ ＣＦCFOCH ₂ (CF ₂ ) _n X [III] (where X is a hydrogen atom or a halogen atom, and n is 1
Is an integer greater than or equal to. Is dissolved in an organic solvent and copolymerized in the presence of a radical polymerization initiator.

Specific examples of the fluorine-containing vinyl ether represented by the general formula [III] used for obtaining the copolymer of the present invention are as follows.

CF ₂ ＣＦCFOCH ₂ CF ₃ , CF ₂ ＣＦCFO
_{CH 2 CF 2 CF 3, CF} 2 = CFOCH 2 CF 2 CF 2 H,
CF ₂ ＣＦCFOCH ₂ (CF ₂ ) ₂ CF ₃ , CF ₂ ＣＦCFOC
H ₂ (CF ₂ ) ₃ CF ₃ , CF ₂ ＣＦCFOCH ₂ (CF ₂ ) ₄ C
F ₃ , CF ₂ ＣＦCFOCH ₂ (CF ₂ ) ₅ CF ₃ , CF ₂ ＣC
FOCH ₂ (CF ₂ ) ₆ CF ₃ , CF ₂ ＣＦCFOCH ₂ (CF
₂ ) ₇ CF ₃ , CF ₂ ＣＦCFOCH ₂ CF ₂ Cl, CF ₂ ＣC
FOCH ₂ CF ₂ Br, CF ₂ = CFOCH ₂ CF ₂ CF ₂ B
_{r, CF 2 = CFOCH 2 CF} 2 CF 2 Cl, CF 2 = CF
OCH ₂ (CF ₂ ) ₂ CF ₂ Br, CF ₂ ＣＦCFOCH ₂ (C
F ₂ ) ₂ CF ₂ Cl, CF ₂ ＣＦCFOCH ₂ (CF ₂ ) ₃ CF ₂
Br, CF ₂ = CFOCH ₂ (CF ₂ ) ₃ CF ₂ Cl or the like.

Next, the above-mentioned fluorine-containing vinyl ether and T
Copolymerization with FE is performed. As a method of copolymerization,
Solution polymerization performed by dissolving the above two monomers in an organic solvent is employed.

In this method, by controlling the monomer composition to be substantially constant, the composition of each monomer unit in the obtained copolymer can be made substantially the same as the monomer composition. As a method of keeping the monomer composition during polymerization substantially constant, a method in which the monomer is not supplied during the polymerization and the polymerization is performed with the monomer composition charged before the polymerization, or the same composition as the monomer composition charged before the polymerization is used. A method of supplying a monomer during polymerization is employed.

In the polymerization, 0.3 to 3 parts of the organic solvent in the solution in which each monomer is dissolved to remove the heat of polymerization is added.
The polymerization can be carried out in the presence of 10 times by weight, preferably 1 to 5 times by weight of water. Of course, since TFE is usually a gas, it is preferable to pressurize and supply the TFE to the gas phase of the polymerization reactor during polymerization.

The organic solvent used for the polymerization is not particularly limited, but chlorofluorocarbons and perfluoro compounds are generally preferably used. For example, trichlorotrifluoroethane, dichlorotetrafluoroethane, trichlorofluoromethane, dichlorodifluoromethane,
Fluorinated solvents such as perfluorocyclohexane, perfluorocyclobutane, perfluorotributylamine, perfluorotriamylamine and perfluoropolyethers are preferred. When the polymerization method is specifically exemplified, a deoxygenated organic solvent and a fluorine-containing vinyl ether are added to a pressure vessel equipped with a stirrer and a thermometer. The proportion of these additions is selected in such a range that the viscosity rises with the progress of the polymerization, making it difficult to stir or that the heat of polymerization cannot be removed due to insufficient stirring, making it difficult to maintain the polymerization. .
Usually, it is preferable to select the fluorinated vinyl ether from the range of 0.1 to 30 parts by weight, preferably 1 to 10 parts by weight based on 100 parts by weight of the organic solvent. Further, water can be allowed to coexist in order to facilitate removal of the heat of polymerization and stirring.

Next, in order to deoxidize the inside of the reaction vessel, for example, an operation of deaeration after cooling and solidifying the contents of the reaction vessel is repeated. Thereafter, TFE is added to the gas phase of the reaction vessel. A radical generator as a polymerization initiator is dissolved in an organic solvent and added, and then TFE is pressurized to a predetermined pressure, and polymerization is performed while maintaining the temperature at the polymerization temperature.

The polymerization time varies depending on the pressure of TFE, the amount of the radical generator to be added, and the like.

The polymerization initiator used in the present method includes, for example, dialkyl peroxide, diacyl peroxide, peroxydicarbonate and azo type. Considering generally the heat resistance of the obtained copolymer,
A fluorine-containing, preferably perfluoro, radical generator is used. For example, a fluorine-containing diacyl peroxide represented by the following formula is preferably used.

[0035]

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(However, Z is -H, -F or -Cl, and y is an integer of 1 to 5.)

[0037]

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(Where Z and y are the same as the above formulas,
q is an integer of 0-3. The following are examples of radical generators that can be suitably used in the polymerization.

[0039]

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The amount of the radical generator used cannot be determined unconditionally depending on the solvent used, the polymerization conditions, especially the polymerization temperature, but is usually 0.5 to 20 mol%, preferably 0.5 to 20 mol%, based on the fluorine-containing vinyl ether used for the polymerization. 1 to 10 mol%
May be added at the time of charging or intermittently. Depending on the conditions, the polymerization may be difficult to proceed. In such a case, it is effective to add the radical generator again during the polymerization.

The pressure of TFE is 1 kg / cm ² G to 30 K
The polymerization reaction proceeds sufficiently within the range of g / cm ² G, but the preferable pressure is 1 kg / cm ² G to 10 kg / cm ^2.
G. When TFE pressure is low, generally TFE
In contrast, when the pressure is high, the TFE content increases, and the production rate of the copolymer increases. Of course, the polymerization proceeds even if the pressure exceeds the lower limit and the upper limit, but if the pressure is too high, there is a disadvantage that the apparatus becomes considerably expensive. The temperature at the time of the polymerization is determined based on the decomposition rate of the radical generator used as one standard.
C. to about 100.degree. C., preferably about 5.degree. Particularly, in the case of a fluorine-containing or perfluoro-based diacyl peroxide having a high decomposition rate even at a low temperature, the temperature is preferably about 5 ° C to 60 ° C.

In the polymerization, by performing the copolymerization in the presence of a chain transfer agent, the tensile strength of the obtained fluorine-containing random copolymer is improved, and the melt viscosity is lowered. This tendency is remarkable when the amount of the monomer unit represented by the general formula [II] is in the range of 0.5 mol% to 10 mol%.

Examples of the chain transfer agent include alcohols such as methanol and ethanol; ethers such as dimethyl ether, methyl ethyl ether and diethyl ether; alkanes such as methane, ethane, propane and butane. Alcohols and alkanes are preferred from the viewpoints of solubility in the polymerization solvent, safety of the produced copolymer, and the like. If the chain transfer agent is a gas, it may be injected at a pressure that can maintain a necessary amount of dissolution in the solvent for polymerization.
In the case of a liquid, the required amount may be added in advance or intermittently. The amount of the chain transfer agent used varies slightly depending on the type and polymerization conditions, but is usually 0.05 to 10 mol%, preferably 0.1 to 5 mol%, based on the total amount of the added monomers.
Is preferred. If the amount of the chain transfer agent is less than this range, the effect of improving the tensile strength is not obtained, or even if it is obtained, the decrease in the melt viscosity is small. Conversely, if the amount is too large, the tensile strength will rather decrease.

Further, a fluoroolefin such as hexafluoropropylene, chlorotrifluoroethylene, or vinylidene fluoride may be added to TFE in order to modify the properties of the obtained copolymer. In general, it is preferable to use 5 mol% or less based on TFE.

The produced copolymer is recovered by separating the organic solvent (and water) from the polymerization mixture. In this case, water can be easily separated from the copolymer by filtration, but the organic solvent has a high concentration of the copolymer dispersed therein and may not be recovered by filtration. In such a case, the copolymer can be recovered by using a centrifuge or by separating the copolymer from the solvent under reduced pressure.

The fluorinated vinyl ether used in the production of the copolymer of the present invention copolymerizes well with TFE, and if the pressure during the polymerization of TFE is 1 kg / cm ² or more, it is almost copolymerized in a short time, and the conversion Can be adjusted to 100%. In such a case, the fluorine-containing vinyl ether is hardly detected in the organic solvent used for the polymerization. Therefore, the step of recovering the fluorinated vinyl ether becomes unnecessary. Conventional PPVE
Has already described that when copolymerized with TFE, the copolymerizability is poor and a recovery step is necessary, but this is one of the great advantages of the above-mentioned production method when compared with this. .

[0047]

The fluorine-containing random copolymer of the present invention contains 0.5 to 10 mol% of a monomer unit based on a fluorine-containing vinyl ether represented by the general formula [II]. Although the copolymer contained hydrogen atoms in the molecule, there was a concern that the chemical resistance was inferior, but in fact the chemical resistance was surprisingly very good, and it was commercially available as a copolymer of PPVE and TFE. PF
Comparable to A and other perfluoro resins. For this reason, films, tubes,
It can be used as packing material, lining material, and other molded products. It also has excellent electrical properties and can be used in the electrical and electronics fields for connectors, substrate materials, insulating materials and others.

It is a molding material having better mechanical properties such as tensile strength than PFA, which is a conventional copolymer of PPVE and TFE, and can be used as a molded product in a wide range of fields.

Further, by fluorinating the fluorine-containing random copolymer of the present invention with a fluorinating agent, for example, F ₂ , it is possible to obtain a high yield without causing the main chain scission observed in the conventional fluorination of hydrocarbon polymers. Can be fluorinated. Therefore, the copolymer of the present invention is also useful as a raw material for a perfluoro copolymer.

[0050]

The present invention will be described in detail with reference to the following examples.

The measured values were obtained as follows.

1. Mechanical properties (i) Measurement of yield strength, tensile strength and elongation According to JIS K7113 (ii) Preparation of test sample The fluorocopolymer powder of the present invention and PFA powder and pellets commercially available for comparison at 350 ° C. , And a sheet having a thickness of 1 to 2 mm was prepared, and test pieces required for the above test method were prepared.

2. Thermal properties (i) Glass transition temperature Measured using DSC-20 (manufactured by Seiko Instruments Inc.).

(Ii) Thermal decomposition temperature and melting point Thermoflex (R-TG-DTA: Rigaku Corporation)
Was measured under a nitrogen stream at a rate of 5 ° C./min.

3. Measurement of melt viscosity A Koka type melt viscosity measuring device was used.

A die having a diameter of 0.5 mm and a length of 5 mm
And measured with a load of 50 kg / cm ² .

4. Optical Properties The fluorine-containing random copolymer powder of the present invention is prepared by using the above-mentioned 1- (i
A film having a thickness of 100 μm was prepared in the same manner as described in the preparation of the test sample in i), and the absorbance of the film to 250 nm light was measured.

Example 1 1,1,2-Trichloro-1, previously purified by distillation in a 3 L stainless steel autoclave having a stirrer.
2,2-trifluoroethane 1 L, CF ₂ ＣＦCFOCH ₂
10 g of CF ₂ CF ₃ , as a polymerization initiator (CF ₃ CF _2.
1,1,2-trichloro-1, containing 1 g of CO ₂ —) ₂ ,
10 cc of 2,2-trifluoroethane was added. After cooling the autoclave with liquid oxygen and solidifying the contents,
Degas with a vacuum pump. Further, nitrogen was introduced to a pressure of 3 kg / cm ^{2, and} the temperature was raised (about −5 ° C.) while maintaining the pressure until the contents were dissolved. This operation was repeated three times to remove oxygen in the autoclave. After cooling and solidifying again with liquid oxygen and degassing with a vacuum pump, the temperature was raised. When the temperature reached about 15 ° C., TFE was introduced at a pressure of 3 kg / cm ² G, and TFE was saturated and dissolved. The introduction valve was closed. The temperature of the autoclave was raised to 20 ° C. to initiate polymerization. When the polymerization was continued for 5 hours, the pressure in the autoclave dropped almost to the vapor pressure of trichlorotrifluoroethane, so the polymerization was stopped. Thereafter, the solvent and unpolymerized CF ₂ ＣＦCFOCH ₂ CF ₂ CF _{3 were} added to the autoclave.
Is connected to a vacuum pump through a trap for cooling and collecting,
The pressure in the autoclave was reduced while stirring, and the used solvent and unpolymerized fluorine-containing vinyl ether were collected in the trap. After the solvent was completely removed, opening the autoclave revealed that a white powdery copolymer had been formed. When the obtained copolymer was dried under reduced pressure at 150 ° C. for 10 hours, about 150 g of the copolymer was obtained.

When the recovered solvent was analyzed by gas chromatography, unpolymerized CF ₂ ＣＦCFOCH ₂ CF ₂
CF ₃ was not detected, and the charged CF ₂ = CFOCH ₂ CF ₂
It was found that CF ₃ was polymerized at almost 100% conversion. The conversion of TFE calculated from the pressure change was about 97%. 400 by pyrolysis gas chromatography mass spectrometry (hereinafter abbreviated as Py-GC / MS)
As a result of analyzing the decomposition product at ° C., CF ₃ CF ₂ CH and CF ₃ CF ₂ CH ₃ were detected as fragments, so that the structure of the side chain could be confirmed to be —OCH ₂ CF ₂ CF ₃ . .

From this result and the result of IR measurement, 3.1 mol% of

[0061]

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It was found that the monomer unit represented by the formula (1) was contained in the copolymer, which was equivalent to 3.0 mol% of the composition at the time of preparation.

Examples 2 to 4 Using the polymerization apparatus and method of Example 1, fluorinated copolymers having different compositions were synthesized. Table 1 shows the conditions which were different from those of Example 1, the conversion rate of the monomer, and the analysis value of the obtained copolymer.

[0064]

[Table 1]

Example 5 In a 300 ml autoclave, CF ₂ ＣＦCFOCH ₂ (C
4.1 g of F ₂ ) ₂ CF ₃ and 1,1,2,3
-Trichloro-1,2,2-trifluoroethane 150
Then, the same deoxidation operation as in Example 1 was performed. Thereafter, TFE was introduced at a pressure of 6 kg / cm ² G, and after the TFE was saturated and dissolved, the TFE supply valve was closed. After adjusting the temperature of the autoclave to 20 ° C., the polymerization initiator (C
_{F 3 CF 2 CF 2 CO 2} -) a trichloro-trifluoroethane solution containing ₂ 0.15 g was 5ml pressed.

When the polymerization was continued for 5 hours, the pressure in the autoclave dropped to about the vapor pressure of the solvent. When the solvent was distilled off under reduced pressure according to the procedure of Example 1, a white powdery copolymer was obtained.

[0067] The recovered solvent was analyzed by gas chromatography _{CF 2 = CFOCH 2 (CF 2} ) 2 CF 3 is not throat detected N殆, was almost 100% conversion. Again T
It was found from the pressure change that the FE also had a conversion of almost 100%.

On the other hand, the obtained copolymer was heated at 150 ° C. for 10 hours.
The product dried under reduced pressure for a period of time was analyzed by Py-GC / MS and IR.

[0069]

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A monomer unit represented by the following formula was contained, which corresponded to 1.45 mol% of the monomer composition at the time of preparation.

Example 6 CF ₂ ＣＦCFOCH ₂ CF was placed in a 300 ml autoclave.
₂ CF ₂ Cl 1.6 g, solvents as 1,1,2-trichloro-1,2,2-trifluoroethane 150 ml, as the polymerization initiator _{(CF 3 CF 2 CO 2 -} ) 2 0.5g was added, implementation Deoxygenation was performed by the operation used in Example 1, TFE was introduced at 3.0 Kg / cm ² G, and after saturation dissolution, T
The supply of FE was stopped, and polymerization was carried out at 20 ° C. for 5 hours.

The obtained white powder copolymer was Py-G
2.7 mol% by C / MS and IR analysis

[0073]

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It was found to contain the monomer unit represented by the following formula. This almost coincided with the monomer composition at the time of charging.

When the conversion of the monomer was measured,
Both TFE and fluorine-containing vinyl ether were almost 98%.

Example 7 Polymerization was carried out in the same manner as in Example 1 except that 7.8 g of CF ₂ ＣＦCFOCH ₂ CF ₃ was used. When polymerization was carried out for 4 hours, the polymerization was almost completed. When the conversions of the fluorinated alkyl vinyl ether and TFE were determined in the same manner as in Example 1, all were approximately 98%. When the obtained copolymer was dried under reduced pressure, it was about 145 g.

The obtained copolymer was analyzed and found to be 3.0 mol%.

[0078]

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The monomer composition of the present invention was almost the same as the charged composition.

Example 8 The thermal decomposition temperature, the melt viscosity and the melting point of the fluorinated random copolymers obtained in Examples 1 to 7 were measured at 300 ° C., and the results are shown in Table 2. In addition, the yield strength, tensile strength and elongation of each fluorine-containing random copolymer were measured, and the results are also shown in Table 2.

[0081]

[Table 2]

Example 9 Each of the fluorine-containing random copolymers obtained in Examples 1 to 7 was tested for chemical resistance. Table 3 shows the results.

[0083]

[Table 3]

Example 10 Using the apparatus of Example 1, copolymerization was carried out while changing the polymerization initiator, the fluorine-containing vinyl ether and the chain transfer agent. Table 4 shows the tensile strength, melting point, melt viscosity and thermal decomposition temperature of the obtained copolymer. The content of the fluorinated vinyl ether units in the copolymer was about 3 mol% in each case.

[0085]

[Table 4]

Example 11 A copolymer was synthesized using the apparatus method and the like of Example 1 except that methanol was added as a chain transfer agent and the conversion of polymerization was changed to 85%. The tensile strength, melt viscosity and melting point of the coalesced were measured. Table 5 shows the obtained results.
It was shown to. The content of the fluorine-containing vinyl ether units in the copolymer was about 3 mol% in each case.

[0087]

[Table 5]

Example 12 In Example 11, copolymerization was carried out using ethane as a chain transfer agent instead of methanol, and the tensile strength and melt viscosity of the obtained copolymer were measured. Table 6 shows the obtained results. The content of the fluorinated vinyl ether units in the copolymer was about 3 mol% in each case.

[0089]

[Table 6]

Comparative Example 1 In the same manner as in Example 1, CF was added to the vinyl ether monomer.
_{When 2} = CFOCH ₂ CF ₂ CF ₃ and the content of the fluorinated vinyl ether alone in the obtained copolymer is 0.3 mol%, the tensile strength of the copolymer is 190 kg /
cm ² .

Example 13 In order to obtain a copolymer composition curve, tetrafluoroethylene and 2,2,3,3,3-pentafluoropropyltrifluorovinyl ether were copolymerized. Freon 113
Was a solvent, as the polymerization initiator (C ₂ F ₅ .COO-) ₂
Was used. Polymerization initiator concentration 0.3 to 1 mol% (based on all monomers), pressure of tetrafluoroethylene 1 to 3 kg
/ Cm ² G, polymerization temperature 20 ° C., monomer conversion rate 5 to 2
A polymerization experiment was performed at 0 mol%. Feynman-Ross (Fi
neman-Ross) method. The results obtained are shown in FIG. For comparison, the copolymer composition curve of perfluoropropyl vinyl ether and tetrafluoroethylene is shown as "Zurnal Pliclad Heimya,
1984, 57 (5), 1126-8 ". The result is shown in FIG.

Comparative Example 2 Deoxygenated water (150 ml) in an autoclave equipped with a 500 cc stirrer, CF ₂ = CFOCH ₂ CF ₂ CF
₃ 4.2 g, 0.1 g of ammonium perfluorooctanoate as an emulsifier, and (NH ₄ ) ₂ S ₂ O ₈ as a polymerization initiator
0.2 g was added. After the system was deoxygenated, 6 kg / cm ^{2 of} tetrafluoroethylene was injected. The temperature of the autoclave was set to 60 ° C., and the polymerization was carried out for 8 hours while maintaining the pressure of tetrafluoroethylene at 6 kg / cm ² . After polymerization,
After filtration and drying, 29 g of a white powder was obtained. When a film was formed by hot pressing and the infrared absorption spectrum was measured, about 6 mol% of CF ₂ ＣＦCFOCH ₂ CF ₂
Monomeric units CF ₃ was included. The melting point in the obtained copolymer is 327 ° C., and the tensile strength is 200 kg /
cm ² . The melt viscosity was 7 × 10 ⁶ poise and the glass transition temperature was 130 ° C.

Comparative Example 3 Using the apparatus of Comparative Example 2, CF ₂ ＣＦCFOCH ₂ CF ₂ CF ₃
And a polymerization experiment was performed under the same conditions. After polymerization for 5 hours, the emulsion was filtered to obtain a copolymer. The weight of the polymer after drying was 12 g. When the polymer was used as a film for measuring an infrared absorption spectrum, a white powder was observed in the transparent film. As a result of measuring the infrared absorption spectrum, about 18 mol% of CF ₂ ＝ CFO
It was found that a monomer unit of CH ₂ CF ₂ CF ₃ was contained. When the melting point was measured by differential thermal analysis,
A small peak was observed at 7 ° C. 80kg tensile strength
/ Cm ² , the melt viscosity at 200 ° C. was 2 × 10 ³ poise, and the glass transition temperature was 130 ° C.

[Brief description of the drawings]

FIG. 1 is a copolymer composition curve in copolymerization of 2,2,3,3,3-pentafluoropropyltrifluorovinyl ether and tetrafluoroethylene.

FIG. 2 is a copolymer composition curve of perfluoropropyl vinyl ether and tetrafluoroethylene.

FIG. 3 is an infrared absorption spectrum of the fluorine-containing random copolymer obtained in Example 1.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 14/18-14/28 C08F 214/18-214/28 C08F 16/12-16/20 C08F 216 / 12-216/20

Claims (1)

(57) [Claims] (A) General formula (1) 90 to 99.5 mol% of a monomer unit represented by the following formula: and (B) a general formula: (Where X is a hydrogen atom or a halogen atom, and n is 1
Is an integer greater than or equal to. ).
5 mol%, and the melt viscosity measured at 350 ° C. is 10
From ^{2 to 107} poise, fluorinated random copolymer, wherein the melting point of two hundred ninety to three hundred and twenty-five ° C..