JPH02276808A - Fluorine-containing random copolymer and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject new copolymer having excellent chemical resis tance, mechanical strength, heat-resistance and melt-moldability by dissolving tetrafluoroethylene and a specific fluorine-containing vinyl ether in all organic solvent and copolymerizing the monomers in the presence of a radical polymeri zation initiator. CONSTITUTION:The objective copolymer composed of 90-99.5mol% of a mono mer unit of formula II and 10-0.5mol% of a structural unit of formula III and having a melt viscosity of 10<2>-10<7> poise measured at 350 deg.C and a melting point of 290-325 deg.C can be produced by dissolving tetrafluoroethylene and a specific fluorine-containing vinyl ether of formula I (X is B or halogen: n is >=1) in an organic solvent (preferably chlorofluorocarbon or perfluoro compound) and copolymerizing the monomers in the presence of a radical polymerization initia tor (e.g. dialkyl peroxide).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a novel fluorine-containing random copolymer and a method for producing the same.

(Prior art and problems to be solved by the invention) Tetrafluoroethylene (hereinafter simply abbreviated as TFFX) has been used as a fluorine-containing resin with excellent chemical resistance, heat resistance, melt moldability, and electrical properties. Doperfluoropropyl vinyl ether (c) is simply abbreviated as PPVE below. ) copolymers (hereinafter abbreviated as PFA) have been produced and are used in a wide range of industrial fields due to their many excellent properties.

However, this copolymer has the following problems. First, the comonomer PPvE is currently produced by reacting a dimer of hexafluoropropene oxide with an alkali metal salt and then thermally decomposing it, but this requires many production steps and some steps have low yields. Therefore, the total number of vehicles collected for PPvE is low. Furthermore, since ppvg has poor polymerizability with TFE, the utilization rate of PPVE, that is, the ratio of the amount of PPVE charged during polymerization is extremely low. For example, according to Japanese Patent Publication No. 48-2223, the utilization rate of PPVEI17) is only a few to 30%. Therefore, expensive pp
A method and process for collecting vE is required. Furthermore, there is also a loss of PPVE in this step, making the copolymer expensive.

On the other hand, British patent aE812116 has a
A homopolymer of a monomer represented by F2=cF-oR (where R is an alkyl radical or a fluorinated alkyl radical) and a copolymer with TFE are shown. However, the above CF2=CF described in this British patent
The copolymerization method of -OR and TFg is an emulsion polymerization method using water as a medium. As confirmed by the inventors,
When copolymerization of CF2-CF-OR and TFg is carried out by emulsion polymerization, the obtained copolymer is CF2-CF'-
Based on OR (despite the introduction of approximately 6 mol% of monomer positions, the melting point is the same as that of TFE homopolymer (327
℃), and the tensile strength of the sheet obtained from this copolymer was as low as 200 Kf/-.

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

(Means for Solving the Problems) In view of the above problems, the present inventors have developed a fluorine-containing olefin that has good copolymerizability with TFE in a wide range of compositions and has a high utilization rate. In order to search for vinyl ether compounds, we synthesized many compounds and repeated copolymerization experiments. As a result, we found that a fluorine-containing vinyl ether with a specific structure has good copolymerizability with TFE, and most of the fluorine-containing vinyl ethers can be copolymerized with TFE in a short time and in a single polymerization. It was discovered that basic vinyl ether can be copolymerized.

They discovered that a copolymer obtained by solution polymerization has excellent chemical resistance, mechanical strength, and heat resistance, as well as excellent melt moldability, and completed the present invention.

That is, the present invention has the following features: (1) (A) General formula [■] +CF20F2 sho CD 90 to 99.5 mol% of monomer units represented by

and (g)) Consists of 10 to 0.5 mol% of monomer units represented by general formula [II) +cF2c'F-)oCH2(CF2)nX [■], 3
It is a fluorine-containing random copolymer characterized by having a melt viscosity of 102 to 107 Boas measured at 50°C and a melting point of 290 to 325°C, and (2) (A) general formula [■ ]+Cvzcyt+[:I] 60 mol% or more and less than 90 mol% of monomer units represented by (B) General formula Cl0) Substitute F20F+ 0CH2(CF2) x CI[] "However, X
is a hydrogen atom or a halogen atom, and n is an integer of 1 or more. The monomer unit represented by J consists of more than 10 mol% and 40 mol% or less, and the melt viscosity measured at 200 ° C. 1o
7 poise and a glass transition temperature of 110° C. or lower.

In the monomer unit represented by the general formula Cl0), X may be a hydrogen atom or a halogen atom (each halogen atom of fluorine, chlorine, bromine, and iodine is employed.
may be an integer of 1 or more, but for reasons such as ease of production of the fluorine-containing random copolymer of the present invention, that is, ease of monopolymerization, n is 1 to 12. Furthermore, it is preferable that it is in the range of 1 to 8.

The composition of each monomer unit represented by the general formula C1) and
99.5 mol%, but K is preferably 7 to improve the melt moldability of the obtained fluorine-containing random copolymer.
o to 99 mol%, and the monomer unit represented by the general formula Cl0) is 0.5 to 40 mol%, preferably 1 to 30 mol%.
It is mole%. When the monomer unit represented by the above general formula [...] is less than 0.5 mol%, melt moldability is poor (on the other hand, when it exceeds 40 mol%, a solid copolymer cannot be obtained. It is undesirable because it becomes oily.

In the fluorine-containing random copolymer of the present invention, the monomer units represented by the above-mentioned general formulas CII and C1l 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 conventional means. However, the melt viscosity of the fluorine-containing random copolymer of the present invention is.

Since it depends on the content and molecular weight of the monomer unit represented by the general formula [■], 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 C1) and Cl0). for example.

When the monomer unit represented by the general formula C [[) is in the range of 0.5 mol % or more and 10 mol % or less,

The melt viscosity measured at 350°C is in the range of 102 to 107 boads, and the above monomer units exceed 10 mol%.
When the amount is less than mol %, the melt viscosity measured at 200° C. is in the range of 10 2 to 10 7 poise.

Further, the fluorine-containing random copolymer of the present invention has a monomer unit represented by the general formula [11] of 0.5 mol% or more and 10
Those in the range of mol% or less have a melting point of 290 to 525°C,
Preferably it is in the range of 290 to 320°C. Since the melting point of the copolymer obtained by emulsion polymerization is 327°C, the fluorine-containing random copolymer of the present invention is clearly distinguished from the copolymer obtained by emulsion polymerization. Further, the fluorine-containing random copolymer of the present invention having the above composition has a thermal decomposition temperature of 37
It is in the range of 0 to 410°C.

Monomer units represented by general formula CIII in a range of more than 10 mol % and less than 40 mol % do not show a clear melting point, but the glass transition temperature is -10°C or less, generally -10 to 40 mol%.
-100°C, which is considerably lower than the glass transition temperature of the copolymer obtained by emulsion polymerization, which is 130°C. Further, the fluorine-containing random copolymer of the present invention having the above composition has good transparency for visible to ultraviolet light, and generally has an absorbance of 250 snow light of 0.4 or less.

The fluorine-containing random copolymer of the present invention has an infrared absorption spectrum (hereinafter referred to as IR) of 2990ffi.
-CH2- group near -', 10H near 900eN-'
2O0F2- group, and 10F2 near 120051-'
- It has absorption bands based on groups, and by confirming and quantifying these absorption bands, it can be confirmed that the fluorine-containing random copolymer of the present invention is a fluorine-containing random copolymer represented by the general formula [formerly The content of vinyl ether-based monomers can be determined.

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

In addition, the structure of the side chain can be confirmed from fragments generated by decomposition of the side chain using pyrolysis gas chromatography mass spectrometry (hereinafter referred to as PY-GC/MS). for example.

Regarding the fluorine-containing random copolymer obtained in Example 1, fragments due to pentafluoropropyl groups can be detected by 11 Py-GC/MS.

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

That is, tetrafluoroethylene and the general formula [■] CF2=
CFOCH2(CF2)nX CI[I][
However, X is a hydrogen atom or a rogen atom, and n is 1
is an integer greater than or equal to ] In this method, a fluorine-containing vinyl ether shown by the following 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 above general formula [111] used in the present invention are as follows.

CF2−CFOCH2CF, CF2<FOCH2
CF2CFs.

CF2-CFOC)! 2CF2CF2H.

CF2=CFOCH2(CF2)20F3.

CF2-cFOCR2 (CFz), CFs.

CF2-cFOCR2(CF2)4CFg-cF2=
cpocH2(CF2)5cFs.

CF2-cFOCR2(CF2)60F51CF2-C
FOCHz (CF2), CFs ICF2-cFOCH
2CF2CA, CF2-CFOCH2CF2Br
.

CF2-CFOCH2CF2CF2Br, CF2-
cFOCH2CF2CF2ct.

FOCH2(CFz)2CF2Br for CF2.

CF2-cFOCR2(CF2) x CF2
CL-CF2 with FOCHz (CFz), CF2Br
.

CF2=CFOCH2(CFz)sCF2CL etc.

Next, copolymerization with the above-mentioned fluorine-containing vinyl nitrate TFE is carried out. As a method of copolymerization, solution polymerization is employed in which the two types of monomers described above are dissolved in an organic solvent.

By controlling the monomer composition to be substantially constant using this method, the composition of each monomer unit in the resulting copolymer can be made substantially the same as the monomer composition.

As a method to keep the monomer composition almost constant during polymerization, 1
A method is adopted in which the monomer is not supplied during the polymerization and the monomer composition is used before the polymerization, or a method in which a seven-mer composition having the same monomer composition as the monomer composition charged before the polymerization is supplied during the polymerization. Ru.

In polymerization, in order to remove polymerization heat, 0.3 to 10 times the weight of the organic solvent in the solution is added to the solution in which each monomer is dissolved,
Preferably, the polymerization can be carried out in the coexistence of 1 to 5 times the weight of water. Of course, since TFE is usually a gas, it is preferably supplied under pressure to the gas phase of the first polymerization reactor during polymerization.

The organic solvent used in the present invention is not particularly limited, but
In general, chlorofluorocarbons and perfluoro compounds are preferably used.

For example, trichlorotrifluoroethane, dichlorotetrafluoroethane, trichlorofluoromethane, dichlorodifluoromethane.

Fluorine solvents such as perfluorocyclohexane, perfluorocyclobutane, perfluorotributylamine, perfluorotriamylamine, and perfluoropolyethers are preferred. To specifically illustrate the polymerization method, a deoxygenated organic solvent and fluorine-containing vinyl ether are added to a pressure vessel equipped with a stirrer and a thermometer. The ratio of these additions should be selected within a range where the viscosity increases as the polymerization progresses, making stirring difficult, or where the heat of polymerization cannot be removed due to insufficient stirring and the maintenance of the polymerization does not become stable. Ru. Usually, it is preferable to select from the range of 0.1 to 301 parts by weight, preferably 1 to 10 parts by weight of the fluorine-containing vinyl ether per 100 parts by weight of the organic solvent. Furthermore, water may be present in order to facilitate removal of polymerization heat and stirring.

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

Although the polymerization time varies depending on the pressure of TFH, the amount of radical generator added, etc., a copolymer can be sufficiently produced in several tens of minutes to several hours.

Examples of the polymerization initiators used in this method include dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and azo-based initiators. Considering the heat resistance of the generally obtained copolymer, a fluorine-containing radical generator, preferably a perfluorinated radical generator, is used. For example, a fluorine-containing diacyl peroxide represented by the following formula is preferably used.

CLCF2CF2C-0-0-CCF2CF2C2II
no 0 Examples of radical generators that can be suitably used in the present invention are as follows.

○ The amount of the above radical generator to be used cannot be determined unconditionally depending on the solvent 1 polymerization conditions used, especially the polymerization temperature, but the amount of CL5
A radical generating agent corresponding to 20 mol %, preferably 1 to 10 mol % may be added at the time of charging or intermittently.

Also, depending on the conditions, polymerization may be difficult to proceed, but in such cases, it is an effective means to add the radical generator again during the polymerization.

The pressure of TFg is I Kt/jG ~30Ke/cIIG
Although the polymerization reaction will proceed satisfactorily within this range, the preferred pressure is from 1 to /-G to 101/jG. 'I'FI
! When the pressure of F is low, a copolymer with a low content of TFg is generally obtained, and conversely, when the pressure is high, the content of TFE is high.

The rate of copolymer production also increases. Of course, the lower limit of pressure,
Polymerization will proceed even if the upper limit is exceeded, but if the pressure is too high, the disadvantage is that the equipment becomes quite expensive. The temperature during polymerization can be determined based on the decomposition rate of the radical generator used, and is usually 0°C to 100°C, preferably 5°C to 80°C. Especially for fluorine-containing or perfluorinated diacyl peroxides which have a high rate of decomposition at low temperatures, the temperature is preferably about 5°C to 60°C.

In the present invention, by carrying out copolymerization in the presence of a chain transfer agent, the resulting fluorine-containing random copolymer has improved tensile strength and reduced melt viscosity. This trend is
It is remarkable when the monomer unit represented by the general formula [11] is in the range of 0.5 mol % or more and 10 mol % or less.

Chain transfer agents used in the present invention include, for example, alcohols such as methanol and ethanol, dimethyl ether, and methyl ethyl ether.

Ethers such as diethyl ether: methane.

Alkanes such as ethane, propane, and butane are used, and among these, alcohols and alkanes are preferred for reasons such as solubility in the polymerization solvent and safety of the produced copolymer.

If the chain transfer agent is a gas, it may be injected under pressure at a pressure that maintains the required amount dissolved in the polymerization solvent; if it is a liquid, the required amount may be added in advance or intermittently. The amount of chain transfer agent used varies slightly depending on the type 9 polymerization conditions, but is usually 0.05 to 10% of the total amount of monomers added.
Mol%, preferably 0.1-5 mol% is preferred. When the amount of the chain transfer agent used is less than this range, the effect of improving tensile strength cannot be obtained, or even if it is obtained, the decrease in melt viscosity is small. On the other hand, if the amount is too high, the tensile strength will actually decrease.

Furthermore, in order to modify the properties of the resulting copolymer, V
Fluoroolefins such as hexafluoropropylene, chlorotrifluoroethylene, and vinylidene trifluoride may be added to C'I'FE. It is generally preferable to use these in an amount of 5 mol % or less based on TFE.

The copolymer produced in Step 2 is recovered by separating the organic solvent (and water) from the polymerization mixture. In this case, water can be easily separated from the copolymer in 0 passes, but the organic solvent disperses the copolymer in a high concentration and may not be recovered by mouth filtration. In such cases, the copolymer can be recovered by using a centrifuge or by separating the copolymer from the solvent under reduced pressure.

The fluorine-containing vinyl ether used in the present invention copolymerizes with TFK, and if the pressure during polymerization of TFE is 1:4/a1 or more, most of the copolymerizes in a short time, resulting in a conversion rate of 100%. I can make a turtle.

In such cases, almost no fluorine-containing vinyl ether is detected in the organic solvent used in the polymerization. Therefore, recovery of fluorine-containing vinyl ether becomes unnecessary. conventional p
When pvg is copolymerized with TFR, the copolymerizability is poor (
.

I already mentioned that you need to collect one ration.

Compared to this, this is one of the major advantages of the above manufacturing method.

(Effects) The fluorine-containing random copolymer of the present invention is based on 0.5 to 40 mol% of fluorine-containing vinyl ether represented by the general formula [1] (contains monomer units).

Since this copolymer contains hydrogen atoms in its molecules, there was a concern that it would have poor chemical resistance, but in fact it actually has surprisingly good chemical resistance, and has been reprinted with a copolymer of ppvg and TFE. Comparable to PFA and other perfluorinated resins.

It can be used as films, tubes, packing materials, lining materials, and other molded products in industrial fields that require chemical resistance. It also has excellent electrical characteristics,
It can also be used in the electronics field as connectors, substrate materials, insulating materials, and more.

Based on the fluorine-containing vinyl ether represented by the general formula Cl0)
Copolymers containing mol % of conventional ppvg and 'I'FE
It is a molding material that has better mechanical properties such as tensile strength than PFA, which is a copolymer with PFA, and can be used as molded products in a wide range of fields.

On the other hand, a copolymer containing 10 to 40 mol % of phosphor units based on a fluorine-containing vinyl ether represented by the general formula [11] is a soft copolymer when compared with a copolymer having a low content.

This copolymer has good chemical resistance, so it can be used as film and tube materials that require chemical resistance, and it also has good light transmission from visible to ultraviolet light, so chemical resistance is required. It can be used as a surface coating material to improve the chemical resistance of optical materials that have conventional chemical resistance.

In addition, molded products such as films and tubes made of soft copolymers are heat-shrinkable and can be used as heat-shrinkable tubes and films.Furthermore, they can be highly fluorinated by introducing crosslinking. It is useful as a fluorinated rubber.

Furthermore, by fluorinating the fluorine-containing random copolymer obtained in the present invention with a fluorinating agent 1, for example, F2, a high yield can be obtained without causing the main chain scission observed in conventional fluorination of hydrocarbon polymers. Can be fluoridated with wealth. Therefore.

The copolymer of the present invention may also be useful as a raw material for perfluoro copolymers [Examples] The present invention will be explained in detail with reference to Examples below.

The measured values were determined as follows.

t Mechanical properties (:) Measurement of yield strength, tensile strength and elongation JIS
Compliant with K7M13 (H) Preparation of test sample The fluorine-containing copolymer powder of the present invention and commercially available PFA powder and pellets for comparison were pressurized at a temperature of 350°C to form a 1 to 2-thick sheet. Preparation 1-1 A test piece required for the above test method was prepared.

Z Thermal Properties (1) Glass transition temperature was measured using DSC-20 (manufactured by Seiko Electronics Co., Ltd.).

(11) Thermal decomposition temperature, melting point Measured using Thermoflex (R-TO-D'rA: manufactured by Rigaku Denki ■) at a temperature increase rate of 5° C./min under a nitrogen stream.

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

50KII using a die of 0.5cm in diameter and 5cm in length.
The measurement was performed by applying a load of /-.

4. Optical properties The fluorine-containing random copolymer powder of the present invention is
A film with a thickness of 100 μm was prepared by the same method as described in the preparation of the test sample in t), and the absorbance of this film to light at 250 nm was measured.

Example 1 1,1,2-trichlor 1.2. which had previously been purified by distillation was placed in a 3 ton stainless steel autoclave equipped with a stirrer.
2-Trifluoroethane IL, CF2-CFOCH
2CF2CFs 101, as a polymerization initiator (CFs
10 Cc of 1°1,2-trichloro-1,2,2-)lifluoroethane containing 1 jl of CFz.co2) was added. The liquid L/-7' was cooled with liquid oxygen to solidify the contents, and then degassed using a vacuum pump. Add 3K of nitrogen
The pressure was introduced to IF/-, and while maintaining the pressure, the temperature was raised (about -5°C) until the contents were dissolved. This operation was repeated three times to remove oxygen in the autoclave. After cooling and solidifying with liquid oxygen again and degassing with a vacuum pump, the temperature is raised.
When the temperature reaches about 15℃, increase TFg to 3 Kt/cfi ()
After saturated dissolution of TFg, 'rF'
Introducing E. The pulp was closed. The temperature of the autoclave is 20
The temperature was raised to 0.degree. C. to initiate polymerization. After continuing the polymerization for 5 hours, the pressure in the autoclave decreased to about the vapor pressure of phototrifluoroethane, so the polymerization was stopped. After that, the solvent and unpolymerized CF2 =
The autoclave was connected to a vacuum pump via a trap for cooling and collecting CFOCH2CF2C, and the pressure inside the autoclave was reduced while stirring, and the used solvent and unpolymerized fluorine-containing vinyl ether were collected in the trap. After completely removing the solvent, the autoclave was opened and a white powdery copolymer had been produced. When the obtained copolymer was dried under reduced pressure at 150° C. for 10 hours, a copolymer of about 1501 was obtained.

Furthermore, when the recovered solvent was analyzed by gas chromatography, unpolymerized CF2=CFOCH2CF2CFs was not detected, indicating that the charged CF2=CFOCF (2CF2CFs) was polymerized with a conversion rate of almost 100%. It turns out.TF
The conversion rate of E was calculated from the pressure change and was about 97%. As a result of analyzing the decomposition products at 400°C by pyrolysis gas chromatography mass spectrometry (hereinafter abbreviated as Py-GC/MS), CF s was detected as a fragment.
Since CF 2 CH and CF 5 CF 2 CH5 were detected, the structure of the side chain was -0CH2CF2CFs
It was confirmed that this was the case.

From this result and the IR measurement result, it was found that 3.1 mol units were contained in the copolymer, which corresponded to the composition at the time of preparation of 3.0 mol %.

Examples 2 to 4 Using the polymerization apparatus and method of Example 1, fluorine-containing copolymers having different compositions were synthesized. Table 1 shows the conditions different from those in Example 1, the conversion rate of monomers, and the analytical values of the obtained copolymer.

Example 5 Autoclave of 500 k CF 2 = CFOCHz (CF 2 ) 2CF 5
The same deoxidation operation as in Example 1 was carried out by adding 1 g of 1.1.2-)sacro-1.2.2-trifluoroethane and 150 d of 1.1.2-)sacro-1.2.2-trifluoroethane as a solvent. Then 'I'F
E was introduced at a pressure of 6 Kf/cs (G), and after TFE was saturated and dissolved, the TFE supply valve was closed. After the temperature of the autoclave was set to 20°C, (CF3C
A trichlorotrifluoroethane solution containing F2CF2CO2) 0-151 was injected for 5 d.

When the polymerization was continued for 5 hours, the pressure inside the autoclave was reduced to approximately 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.

When the recovered solvent was analyzed by gas chromatography, almost no CF2=CFOCR2(CF2)2.CF5 was detected, and the conversion rate was nearly 100%. Also TF
It was also found that the conversion rate of E was almost 100% from the pressure change.

On the other hand, when the obtained copolymer was dried under reduced pressure at 150°C for 10 hours and analyzed by PY-GO/MS and IR, it was found that it contained about 1.4 mol%, and the monomer composition at the time of preparation was 1. It corresponded to .45 mol%.

Example 6 300d autoclave K (1?F2 =CFOCH2CF2CF2C11,t5
．． 9. lf, 2-trichloro-1,2,2- as a solvent
Trifluoroethane 150d, as a polymerization initiator (CF
Add 0.5 g of sCF2/C02, deoxidize using the same procedure as in Example 1, introduce 'rFE at 3.0 odors/cdG, and after saturated dissolution, stop supplying TFE and heat at 20°C.
Polymerization was carried out for 5 hours.

The obtained white powder copolymer was found to contain 2.7 mol% by PY-GC/MS and rR analysis. This almost corresponded to the composition of the exposed body at the time of preparation.

Furthermore, when the monomer conversion rate was measured, it was approximately 98% for both TFE and fluorine-containing vinyl ether.

Example 7 Polymerization was carried out in the same manner as in Example 1 except that CF2=CFOCH2CF was used at 7.81. After 4 hours of polymerization, the polymerization was almost completed. The conversion rates of the fluorine-containing alkyl vinyl ether and TFE were determined in the same manner as in Example 1, and both were approximately 98%. When the obtained copolymer was dried under reduced pressure, it had a molecular weight of about 14,511.

Analysis of the obtained copolymer revealed 3.0 Example 1
Thermal decomposition temperature of the fluorine-containing random copolymer obtained in ~7 -! The melt viscosity and melting point were measured at 100°C and the results are shown in Table 2. Further, the yield strength, tensile strength and elongation of each fluorine-containing random copolymer were measured, and the results are also shown in Table 2.

This was consistent with the composition of the preparation.

Example 9 A fluorine-containing random copolymer was prepared in the same manner as in Example 1 using various fluorine-containing vinyl ethers shown in Table 1EB and increasing the charging ratio of fluorine-containing vinyl ether to tetrafluoroethylene. was manufactured. Table 3 shows the physical properties of the obtained fluorine-containing random copolymer.

Example 10 The chemical resistance of each of the fluorine-containing random copolymers obtained in Examples 1 to 7 and Example 9 was tested. The results are shown in Table 4.

Example 11 Using the apparatus of Example 1, copolymerization was carried out by changing the polymerization initiator, fluorine-containing vinyl ether, and chain transfer agent. Table 5 shows the tensile strength, melting point, melt viscosity, and thermal decomposition temperature of the obtained copolymer. The content of fluorine-containing vinyl ether units in the copolymer was about 3 mol % in all cases.

Example 12 A copolymer was synthesized using the apparatus method of Example 1, etc., except that methanol was added as a chain transfer agent and the conversion group for polymerization was 85%, and the tensile strength of the obtained copolymer was Strength, melt viscosity and melting point were measured. In addition, the content of 7 in the copolymer
-/ The content of elementary hinyl ether units was about 3 mol% ftL4.

Example 13 Copolymerization was carried out in Example 12 using ethane as a chain transfer agent instead of methanol, and the tensile strength and melt viscosity of the resulting copolymer were measured. The results obtained are shown in Table 7.

The content of fluorine-containing vinyl ether units in the copolymer was approximately 3 mol %.

Example 14 To determine the copolymerization composition curve, one tetrafluoroethylene,! -2.2,3,3.5-pentafluoroprobyl trifluorovinyl ether was copolymerized. Freon 1
13 as a solvent.

(C2F5.C'OO+ was used as a polymerization initiator.

Polymerization initiator concentration 0.3-1 mol o/n (relative to all monomers), tetrafluoroethylene pressure 1-3 to 9/shoulder G
Polymerization experiments were conducted at a polymerization temperature of 20° C. and a monomer conversion rate of 5 to 20 mol%.

A copolymerization composition curve was determined according to the Fineman-Ross method. The results obtained are shown in FIG. In addition, for comparison, the copolymerization composition curve of perfluoropropyl vinyl ether and tetrafluoroethylene is shown in "Zurnar Priklad Himya, May 1984.
7(5).

It was calculated using the copolymerizability ratio described in 1126-8JK.

The results are shown in Figure 2.

Comparative Example 1 150 ml of deoxidized water in an autoclave equipped with a 500 CH stirrer 117°CF2=CFOCH2CF2CFs A-21-Ammonium perfluorooctanoate as emulsifier 0. IL
Te(NH4) 282080.21 was added as a polymerization initiator. After deoxidizing the system, 6 units of tetrafluoroethylene was injected into the system. Autoclave temperature to 60°C
The pressure of tetrafluoroethylene was maintained at 6 KI/cd and polymerization was carried out for 8 hours. After polymerization, it was taken and dried 2
9 g of white powder was obtained. When a film was made by heat pressing and its infrared absorption spectrum was measured, it was found to be approximately 6 mol% CF2=CFOCH2CF2CF.

was included. The melting point of the obtained copolymer was 327°C
The tensile strength was 200Kt/i. Also, the melt viscosity is 7 x 10' poise, and the glass transition temperature is 13
It was 0°C.

Comparative Example 2 CF2-CFOCH2CF2C using the apparatus of Comparative Example 1
A polymerization experiment was conducted under the same conditions by adding 15N of F3.

After 5 hours of polymerization, the emulsion was mixed to obtain a copolymer. The weight of the polymer after drying was 121. When the polymer was placed on a film to measure its infrared absorption spectrum, white powder was observed inside the transparent film.

As a result of infrared absorption spectrum measurement, approximately 18 mol% CF
It was found that 2-CFOCH2CF2CFs was contained. In addition, when the melting point was measured by differential thermal analysis, it was found to be 3
A small peak was observed at 27°. The tensile strength is 80 to 4F/-, the melt viscosity at 200℃ is 2X10'',
The glass transition temperature was 130°C.

[Brief explanation of drawings]

FIG. 1 is a copolymerization composition curve in the copolymerization of 2.2.3.5.3-pentafluoroprobyl triple orovinyl ether and tetrafluoroethylene. Figure 2 4-1 is a copolymerization 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.

Claims (4)

[Claims] (1) (A) 90 to 99.5 mol% of monomer units represented by the general formula -(CF_2CF_2)-, and (B) general formula▲There are numerical formulas, chemical formulas, tables, etc.▼ [However, X is hydrogen atom or a halogen atom, and n is an integer of 1 or more. ] Consisting of 10 to 0.5 mol% of monomer units represented by
A fluorine-containing random copolymer characterized by a temperature of 5°C. (2) (A) General formula - (CF_2CF_2) - Monomer units of 60 mol% or more and less than 90 mol% and (B) General formula ▲ Numerical formulas, chemical formulas, tables, etc. are included ▼ [However, X is hydrogen atom or a halogen atom, and n is an integer of 1 or more. ] Consisting of more than 10 mol% and 40 mol% or less of monomer units represented by
A fluorine-containing random copolymer characterized by a temperature of 10°C or less. (3) Tetrafluoroethylene and the general formula CF_2=CFOCH_2(CF_2)_nX [However,
X is a hydrogen atom or a halogen atom, and n is an integer of 1 or more. ] The fluorine-containing vinyl ether according to claim 1 or 2, wherein the fluorine-containing vinyl ether is dissolved in an organic solvent and copolymerized in the presence of a radical polymerization initiator. Method for producing random copolymer. (4) Tetrafluoroethylene and the general formula CF_2=CFOCH_2(CF_2)_nX [However,
X is a hydrogen atom or a halogen atom, and n is an integer of 1 or more. ] The fluorine-containing random copolymer according to claim (1), characterized in that a fluorine-containing vinyl ether represented by the above is dissolved in an organic solvent and copolymerized in the presence of a radical polymerization initiator and a chain transfer agent. Method for producing polymers.