JP2012153766A - Fluororesin composition, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluororesin composition greatly improved in the elastic modulus at high temperatures, a tube for a soak composed of the same, and a method for manufacturing the composition.SOLUTION: The fluororesin composition includes a melt-processable fluororesin, and a copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and vinylidene fluoride and of 310 to 360°C in melting point.

Description

The present invention relates to a fluororesin composition and a method for producing the fluororesin composition.

A fluorine resin material such as tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer [PFA] is used for a chemical piping member used in a wet process of semiconductor manufacturing. Conventionally used fluororesins are excellent in chemical resistance, etc., but the elastic modulus decreases at high temperatures, so if the chemicals used in the wet process of semiconductor manufacturing are hot, these This fluororesin was not sufficient as a material for the chemical liquid piping member, such as being deformed or insufficient in strength.

As a method for improving the elastic modulus at a high temperature of the fluororesin, for example, addition of a glass filler or the like to the fluororesin has been studied, but there is a concern about elution of the filler component into the chemical solution, and the method is not sufficient. . Accordingly, development of a fluororesin composition having improved elastic modulus and creep properties at high temperatures that can withstand high temperature use of chemicals while maintaining the properties such as chemical resistance and cleanliness possessed by fluororesins has been eagerly desired. .

Further, a copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene (hereinafter referred to as hexafluoroisobutylene) and vinylidene fluoride [VdF] has excellent resistance to acid and alkaline chemicals. It is known that it exhibits chemical properties, has a high melting point, and good thermal stability (see, for example, Patent Documents 1 and 2). However, a molded product obtained by using the copolymer alone is hard but brittle, and its use as a molded member has been limited. Further, a mixed composition composed of hexafluoroisobutylene / VdF copolymer and low molecular weight powdered polytetrafluoroethylene [PTFE], a polymer alloy composed of hexafluoroisobutylene / VdF copolymer and PTFE, etc. are known ( For example, see Patent Documents 3 and 4). However, in any document, a hexafluoroisobutylene / VdF copolymer is added to PTFE, and a melt-processable fluororesin such as PFA is not disclosed. Therefore, at present, a composition containing a melt-processable fluororesin such as PFA and a hexafluoroisobutylene / VdF copolymer is not yet known.

Japanese Patent Publication No.49-32785 US Pat. No. 3,706,723 Japanese Patent Publication No.59-25820 Japanese Unexamined Patent Publication No. 5-78497

The present invention provides a fluororesin composition having greatly improved elastic modulus and creep characteristics at high temperatures. Moreover, this invention provides the manufacturing method of the tube for chemical | medical solutions obtained by shape | molding this fluororesin composition, and a fluororesin composition.

The present invention relates to a melt-processable fluororesin and a fluororesin composition comprising a copolymer of hexafluoroisobutylene and vinylidene fluoride having a melting point of 310 to 360 ° C.

The melt-processable fluororesin is preferably a tetrafluoroethylene / hexafluoropropylene copolymer or a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer.

The melt-processable fluororesin is preferably a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer.

The copolymer of hexafluoroisobutylene and vinylidene fluoride is preferably 8 to 70 parts by weight with respect to 100 parts by weight of the fluororesin solid content that can be melt processed.

Furthermore, it is preferable to contain polytetrafluoroethylene.

Moreover, this invention relates to the tube for chemical | medical solutions obtained by shape | molding the said fluororesin composition.

Furthermore, the present invention relates to a method for producing a fluororesin composition, comprising a step of melt-kneading a melt-processable fluororesin and a copolymer of hexafluoroisobutylene and vinylidene fluoride at a temperature equal to or higher than the melting point of both. .

The fluororesin composition of the present invention is excellent in chemical resistance and heat resistance, and can greatly improve the elastic modulus and creep characteristics at high temperatures. Moreover, the tube obtained by shape | molding the fluororesin composition of this invention is useful as a tube for chemical | medical solutions. Furthermore, this invention also provides the manufacturing method of a fluororesin composition.

The fluororesin composition of the present invention comprises a melt-processable fluororesin, and a copolymer of hexafluoroisobutylene and vinylidene fluoride having a melting point of 310 to 360 ° C. And

The melt-processable fluororesin is a fluororesin having melt fluidity, such as TFE / hexafluoropropylene [HFP] copolymer [FEP], TFE / perfluoro (alkyl vinyl ether) [PAVE] copolymer. [PFA], ethylene [Et] / TFE copolymer, Et / TFE / HFP copolymer, polychlorotrifluoroethylene [PCTFE], CTFE / TFE copolymer, Et / CTFE copolymer, polyvinylidene fluoride [ PVdF], TFE / VdF copolymer, VdF / HFP / TFE copolymer, VdF / HFP copolymer, and polyvinyl fluoride [PVF]. Among these, PFA and FEP are preferable, and PFA is more preferable.

Note that low molecular weight PTFE having a molecular weight of about 500 to 600,000 can be melted and flowed, but a molded product obtained from such low molecular weight PTFE has no mechanical properties and is very brittle. Therefore, in the present invention, such low molecular weight PTFE is not said to be melt-processable and does not correspond to the “melt-processable fluororesin” used in the present invention.

Hereinafter, PFA and FEP will be described.

PFA is a copolymer composed of TFE and PAVE, and the content of PAVE units in all monomer units is preferably 1 to 5 mol%.

PAVE in the PFA is preferably perfluoro (methyl vinyl ether) [PMVE], perfluoro (ethyl vinyl ether) [PEVE], perfluoro (propyl vinyl ether) [PPVE], perfluoro (butyl vinyl ether), or the like. The PAVE is preferably PPVE, PEVE, and PMVE from the viewpoint of heat resistance, and more preferably PPVE.

FEP is a copolymer composed of TFE and HFP, and the content of HFP units in all monomer units is preferably 1 to 15 mol%.

The melt-processable fluororesin used in the present invention preferably has an MFR of 1 to 75 (g / 10 minutes), more preferably 1 to 40 (g / 10 minutes). The MFR is a value that can be measured under the conditions of a temperature of 372 ° C. and a load of 5.0 kg in accordance with ASTM D-1238. Hereinafter, the MFR measurement in this specification follows the above method.

Moreover, it is preferable that melting | fusing point of the melt-processable fluororesin used by this invention is 150-320 degreeC, It is more preferable that it is 240-310 degreeC, It is further more preferable that it is 280-310 degreeC. Here, the melting point in this specification is a temperature corresponding to a melting peak when the temperature is increased at a rate of 10 ° C./min using a differential scanning calorimeter [DSC].

The copolymer of hexafluoroisobutylene and VdF (hereinafter sometimes referred to as “hexafluoroisobutylene / VdF copolymer”) may be a copolymer having a melting point of 310 to 360 ° C. The melting point of the hexafluoroisobutylene / VdF copolymer is preferably 310 to 340 ° C, and more preferably 320 to 335 ° C.

Hexafluoroisobutylene / VdF copolymer can be modified with a small amount of monomer as the third component to control the melting point as a terpolymer or higher copolymer. The content of VdF units in the monomer units is preferably 40 to 60 mol%, and more preferably 45 to 55 mol%. Among the copolymers of hexafluoroisobutylene and VdF, a 1: 1 alternating copolymer of hexafluoroisobutylene and VdF (hereinafter sometimes referred to as “hexafluoroisobutylene / VdF alternating copolymer”) is high temperature. It is preferable from the point that the elastic modulus can be greatly improved. The content of hexafluoroisobutylene units in all monomer units is preferably 40 to 60 mol%, and more preferably 45 to 55 mol%. Moreover, it is preferable that it is 0-10 mol%, and, as for content of the unit based on the 3rd component which occupies for all the monomer units, it is more preferable that it is 0-5 mol%.

The hexafluoroisobutylene / VdF copolymer has a structure in which the rigidity of the main chain is remarkably high, and exhibits excellent chemical resistance to acid and alkaline chemicals.

In the present invention, by adding a hexafluoroisobutylene / VdF copolymer, particularly a hexafluoroisobutylene / VdF alternating copolymer, to a melt-processable fluororesin, the elastic modulus at a high temperature is greatly improved. It is something that can be done.

The hexafluoroisobutylene / VdF copolymer can be produced according to Japanese Patent Publication No. 49-32785 (Patent Document 1) and US Pat. No. 3,706,723 (Patent Document 2), and further as a third component. It is also possible to use hexafluoropropylene, tetrafluoroethylene, chlorotrifluoroethylene, perfluorovinyl ether (PFVE) and the like. As said PFVE, perfluoro (alkyl vinyl ether) [PAVE] is mentioned, for example. PAVE has the general _{formula: CF 2 = CFO (CF 2} ) n CF 3 ( wherein, n represents an integer of 0 to 3.) Is a compound represented by the.

Examples of PAVE include perfluoro (methyl vinyl ether) [PMVE], perfluoro (ethyl vinyl ether) [PEVE], perfluoro (propyl vinyl ether) [PPVE], perfluoro (butyl vinyl ether), and the like.

Specifically, it can be produced by a polymerization method such as solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization or the like, and can be produced by emulsion polymerization or suspension polymerization in terms of industrial implementation. preferable.

In the above polymerization, a polymerization initiator, a surfactant, a chain transfer agent, and a solvent can be used, and conventionally known ones can be used.

As the polymerization initiator, an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator can be used.

The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, such as diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, etc. Dialkyl peroxycarbonates, peroxyesters such as t-butylperoxyisobutyrate and t-butylperoxypivalate, dialkylperoxides such as di-t-butylperoxide, and the like. ω-hydro-dodecafluoroheptanoyl) peroxide, di (ω-hydro-tetradecafluoroheptanoyl) peroxide, di (ω-hydro-hexadecafluorononanoyl) peroxide, di (perfluorobutyryl) per Oxide, di (perfluorovaleryl ) Peroxide, di (perfluorohexanoyl) peroxide, di (perfluoroheptanoyl) peroxide, di (perfluorooctanoyl) peroxide, di (perfluorononanoyl) peroxide, di (ω-chloro-) Hexafluorobutyryl) peroxide, di (ω-chloro-decafluorohexanoyl) peroxide, di (ω-chloro-tetradecafluorooctanoyl) peroxide, ω-hydro-dodecafluoroheptanoyl-ω-hydrohexa Decafluorononanoyl-peroxide, ω-chloro-hexafluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydrododecafluoroheptanoyl-perfluorobutyryl-peroxide, di (dichloropentafluoro Butanoyl) peroxide, di (trichlorooctafluorohexanoyl) peroxide, di (tetrachloroundecafluorooctanoyl) peroxide, di (pentachlorotetradecafluorodecanoyl) peroxide, di (undecachlorodotria contourer) Fluorodocosanoyl) peroxide di [perfluoro (or fluorochloro) acyl] peroxides and the like are typical examples.

The water-soluble radical polymerization initiator may be a known water-soluble peroxide, for example, ammonium salts such as persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, percarbonate, potassium salts, sodium salts. , T-butyl permaleate, t-butyl hydroperoxide and the like. A reducing agent such as sulfites and sulfites may be used in combination with the peroxide, and the amount used may be 0.1 to 20 times the peroxide.

As the surfactant, a known surfactant can be used. For example, a nonionic surfactant, an anionic surfactant, a cationic surfactant, or the like can be used. Among these, fluorine-containing anionic surfactants are preferable, and may include ether-bonded oxygen (that is, oxygen atoms may be inserted between carbon atoms), linear or branched having 4 to 20 carbon atoms. A fluorine-containing anionic surfactant is more preferable. The addition amount (with respect to polymerization water) is preferably 50 to 5000 ppm.

Examples of the chain transfer agent include hydrocarbons such as ethane, isopentane, n-hexane and cyclohexane; aromatics such as toluene and xylene; ketones such as acetone; acetates such as ethyl acetate and butyl acetate; Examples include alcohols such as methanol and ethanol; mercaptans such as methyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride, chloroform, methylene chloride, and methyl chloride. The addition amount may vary depending on the chain transfer constant of the compound used, but is usually used in the range of 0.01 to 20% by mass with respect to the polymerization solvent.

Examples of the solvent include water, a mixed solvent of water and alcohol, and the like.

In the suspension polymerization, a fluorine-based solvent may be used in addition to water. Examples of the fluorine-based solvent include hydrochlorofluoroalkanes such as CH ₃ CClF ₂ , CH ₃ CCl ₂ F, CF ₃ CF ₂ CCl ₂ H, CF ₂ ClCF ₂ CFHCl; CF ₂ ClCFClCF ₂ CF ₃ , CF ₃ CFClCFClCF _3, etc. Perfluoroalkanes such as perfluorocyclobutane, CF ₃ CF ₂ CF ₂ CF ₃ , CF ₃ CF ₂ CF ₂ CF ₂ CF ₃ , CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₃ , etc. Can be mentioned. Of these, perfluoroalkanes are preferred. The amount of the fluorine-based solvent used is preferably 10 to 100% by mass with respect to the aqueous medium from the viewpoint of suspendability and economy.

It does not specifically limit as polymerization temperature, It may be 0-100 degreeC. The polymerization pressure is appropriately determined according to other polymerization conditions such as the type, amount and vapor pressure of the solvent to be used, the polymerization temperature, etc., but may usually be 0 to 9.8 MPaG.

The blending ratio of the hexafluoroisobutylene / VdF copolymer is preferably 8 to 70 parts by weight and more preferably 10 to 25 parts by weight with respect to 100 parts by weight of the solid content of the melt-processable fluororesin. preferable. The addition range of the copolymer is in the above range, which is preferable for improving the elastic modulus and maintaining the flex life of the molded product.

In addition to the melt-processable fluororesin and hexafluoroisobutylene / VdF copolymer, the resin composition of the present invention may further contain polytetrafluoroethylene [PTFE] from the viewpoint of improving flex life (MIT). preferable. PTFE acts as a crystallization accelerator. That is, PTFE starts to crystallize at a higher temperature than the melt-processable fluororesin, so that the crystallized PTFE serves as a nucleus to promote crystallization of the melt-processable fluororesin. ) Can be improved.

High molecular weight PTFE having a fibrillation property and non-melt processability is inferior in dispersibility in a melt-processable fluororesin, but low molecular weight PTFE has good dispersibility. Therefore, as PTFE used in the present invention, Low molecular weight PTFE having a number average molecular weight of 600,000 or less is preferred. If it exceeds 600,000, the fibrillation characteristics are manifested and the particles tend to aggregate, which may result in poor dispersibility. The number average molecular weight of PTFE is preferably within the above range, and the lower limit can be set to 10,000, for example.

The number average molecular weight of PTFE can be determined by the following method.
(1) The standard specific gravity (SSG) of a sample molded under a certain heat treatment condition shown in ASTM D4894 is a number average corrected by a radiation end group method or a melt viscosity method at a high temperature. It is related to the molecular weight (Mn), and the following formula is established.
S. S. G = −0.0579 log (Mn) +2.6113
Therefore, it can be obtained by the above formula.
This method is based on the premise that a molded body for standard specific gravity measurement can be formed. In other words, since low molecular weight PTFE has a low melt viscosity, a molded product cannot be obtained by melting and flowing during firing, or even if a molded body is obtained, cracks and foaming often occur, and the standard specific gravity cannot be measured. The following method is adopted.

(2) Low molecular weight PTFE The number average molecular weight can be determined by a semi-treatment with the method of Wu (Polymer Engineering & Science, 1988, Vol. 28, 538, 1989, Vol. 29, 273). This method is a method for calculating the number average molecular weight, weight average molecular weight, and molecular weight distribution from the elastic modulus at the time of melting of the resin, and is particularly useful for measuring the molecular weight of a resin insoluble in a solvent represented by PTFE. The measuring device uses a viscoelasticity measuring machine MCR500 manufactured by Anton Paar, and measures dynamic viscoelasticity at 380 ° C. However, a parallel plate is used as a jig for holding the sample, the thickness when the sample is melted is 1.4 to 1.5 mm, and the frequency range is 0.001 to 500 rad / sec. The deformation amount of the sample at the time of melting is selected from a range of 0.8 to 3% on the circumference with respect to the thickness of the sample when the frequency is 1 rad / second or more, and 2 to 2 when the frequency is 1 rad / second or less. Select from a range of 10%. The sampling frequency of the measurement values is 5 points per digit at regular logarithmic intervals. Further, in two consecutive measurements, the measurement is repeated until the average deviation of the storage elastic modulus (G ′ (ω)) at each measurement frequency (ω) is 5% or less. Using the frequency (ω) and storage elastic modulus (G ′ (ω)) obtained by measurement, S.P. The number average molecular weight (Mn) was determined according to the Wu method. However, time t = 1 / ω and G (t) = G ′ (ω).

The PTFE used in the present invention preferably has a melting point of 322 to 347 ° C.

The PTFE used in the present invention may be a tetrafluoroethylene (TFE) homopolymer or a modified PTFE modified with a known modifier. Examples of such commercial products of PTFE particles include, for example, Lubron (for example, Lubron L5) manufactured by Daikin Industries, Ltd.

The blending ratio of PTFE is preferably 0.5 to 10 parts by weight and more preferably 1 to 5 parts by weight with respect to 100 parts by weight of the solid content of the melt-processable fluororesin. The addition range of the copolymer is preferable from the viewpoint of dispersibility in a melt-processable fluororesin.

The MIT value of the fluororesin composition of the present invention may be used several times for member applications that are used under no load, but is 10,000 (times) or more for member applications that are used where there is stress deformation. Preferably there is. Here, the MIT value is a value measured in accordance with ASTM D 2176-69, and is a value measured for a molded body (0.2 mm thick sheet) obtained using the fluororesin composition. The MIT value is an index of bending fatigue resistance.

In the fluororesin composition of the present invention, the elastic modulus at high temperature (180 ° C.) is preferably 60 MPa or more, and more preferably 100 MPa or more. Here, the elastic modulus is a value measured by the method described in the examples, and is a value measured for a molded body (compressed sheet) obtained using the fluororesin composition.

Applications of the fluororesin composition of the present invention include applications that require creep resistance, such as battery gaskets, OA roll cover materials that require wear resistance, high-temperature chemical transport tubes, and offshore (offshore) petroleum. Examples include rigs and platform oil hoses, riser drilling systems, composite materials for large-diameter riser pipes, and applications as wire covering materials. Especially, it can use suitably as a tube for chemical | medical solutions used for a semiconductor manufacturing apparatus, piping material, a valve, a filter housing, a wafer basket, a coupling, a nut, a pump housing, various parts, etc.

Furthermore, this invention relates to the manufacturing method of a fluororesin composition.

The present invention relates to a method for producing a fluororesin composition comprising a step of melt-kneading a melt-processable fluororesin and a copolymer of hexafluoroisobutylene and vinylidene fluoride at a temperature equal to or higher than the melting point of both.

The melt-processable fluororesin and the copolymer of hexafluoroisobutylene and vinylidene fluoride are as described above.

Since the melt-processable fluororesin is kneaded in a molten state, it may be a powder, a tableted product, or an extruded pellet, and the shape is not limited. The particle size of the powder is not particularly limited because the dispersibility can be optimized by the screw configuration of the mixing apparatus and the mixing supply method, but for example, from the viewpoint of handleability, it is 0.1 to 500 μm. It is preferable that the thickness is 0.1 to 50 μm. Similarly, the particle size of the copolymer powder of hexafluoroisobutylene and vinylidene fluoride is not limited.

The melt kneading can be performed by a method usually used in this field, and examples thereof include a uniaxial extruder, a biaxial extruder, a Banbury mixer, a Brabender mixer, and a lab plast mill. be able to. Among these, a lab plast mill and a biaxial extruder are preferable from the viewpoint of improving dispersibility by melt kneading, and a biaxial extruder is more preferable from the viewpoint of mass productivity.

The melt kneading temperature may be any one that is melt kneaded at a temperature equal to or higher than the lower melting point of the melting point of a melt-processable fluororesin or a copolymer of hexafluoroisobutylene and vinylidene fluoride.

For example, when PFA is used as a melt-processable fluororesin, the melting point of PFA is usually 305 ° C., and the melting point of hexafluoroisobutylene / vinylidene fluoride copolymer is usually 324 to 327 ° C. Accordingly, the melt kneading temperature is preferably equal to or higher than the melting point of PFA having a lower melting point, more preferably 330 to 380 ° C, and particularly preferably 330 to 360 ° C. In addition, the melt kneading time by the lab plast mill is preferably 2 to 30 minutes, and more preferably 5 to 15 minutes.

About other melt-kneading conditions, such as a shear rate in the case of using an extruder etc., it can set suitably with the composition of the fluororesin composition to manufacture.

Next, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited to such examples.

(Elastic modulus measurement)
The storage elastic modulus (Er) at 25 ° C., 180 ° C. and 200 ° C. of the compression molded sheet was measured under the following conditions using a dynamic viscoelasticity measuring device (DVA-220 manufactured by IT Measurement Control Co., Ltd.). Asked.
(A) Sample width: 5 mm, thickness: 0.2 mm
(B) Measurement temperature range: 20 to 270 ° C
(C) Frequency: 10Hz
(D) Temperature rising rate: 2 ° C./min

(Measurement of tensile strength (TS) and elongation (EL))
Using a tensile tester (manufactured by Shimadzu Corporation, AUTOGRAPH AG-1), a punched sample was prepared from a compression-molded sheet having a thickness of 2 mm in accordance with ASTM D-638 under the following conditions. Elongation was measured.
(A) Dumbbell shape: ASTM TypeV
(B) Distance between chucks: 25 mm
(C) Tensile speed: 50 mm / min

(MIT value)
In accordance with ASTM D 2176-69, a MIT-type bending fatigue tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used to sample 12 cut out from a compression molded film having a thickness of 0.20 to 0.23 mm. .15N (1.25 kgf) load was applied, and measurement was performed at a bending speed of 178 times / minute and a bending angle of 135 degrees.

(MFR)
Based on ASTM D-1238, the measurement was performed under conditions of a temperature of 372 ° C. and a load of 5.0 kg.

(Shore D hardness)
Measurement was performed according to ASTM D-2240 using a Shore hardness meter manufactured by Toyo Seiki Seisakusho. As a sample, a compression-molded sheet (thickness: 2 mm) was used.

(Dispersibility)
A compression-molded sheet having a thickness of 0.2 mm was observed with the naked eye. In addition, when the additive component was localized and not dispersed, it was judged that the dispersion was bad and indicated by x.

(Creep characteristics)
In accordance with test method ASTM-D621, a cylindrical test piece having a diameter of 11.3 mm and a height of 10 mm is prepared from a compression molded sheet, and a compression creep test is performed in a 200 ° C. oven under a load of 50 kg for 24 hours. The total deformation rate was determined. Further, the load was removed and the deformation rate after 24 hours was determined as permanent deformation.

Example 1
PFA pellet 1 (pellet shape (cylindrical, average outer diameter 2 mmφ, average length 3 mm), melting point: 300 ° C., MFR: 29.5 g / 10 min, TFE / PPVE: 97.9 / 2.1 (mol%) ) And hexafluoroisobutylene / VdF alternating copolymer powder (hexafluoroisobutylene / VdF: 51/49 (mol%), average particle size: 5 μm, melting point: 326 ° C., MFR: 89.0 g / 10 min (temperature: 372 ° C.) , A load of 5.0 kg)) was melt-kneaded at 350 ° C. for 10 minutes using a lab plast mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a blending ratio shown in Table 1. The evaluation results for the obtained composition are shown in Table 1.

Examples 2-4
A fluororesin composition was obtained in the same manner as in Example 1 except that the hexafluoroisobutylene / VdF alternating copolymer powder was blended in the blending ratio shown in Table 1. The evaluation results for the obtained composition are shown in Table 1.

Examples 5-6
PFA pellets 2 (melting point: 306 ° C., MFR: 14.6 g / 10 min, TFE / PPVE: 98.3 / 1.7 (mol%)), PFA pellets 3 (melting point: 308 ° C., MFR: 1) .97 g / 10 min, TFE / PPVE: 98.5 / 1.5 (mol%)), except that the blending ratio of the hexafluoroisobutylene / VdF alternating copolymer powder was changed to the ratio shown in Table 1. A fluororesin composition was obtained in the same manner as in Example 1. The evaluation results for the obtained composition are shown in Table 1.

Example 7
Lab Plast Mill (Toyo Seiki Seisakusho Co., Ltd.) with the blending ratio shown in Table 1 of PFA pellet 1, hexafluoroisobutylene / VdF alternating copolymer powder, and PTFE powder 1 (number average molecular weight: 400,000, melting point: 327 ° C.) ) At 150 ° C. for 10 minutes. The evaluation results for the obtained composition are shown in Table 1.

Examples 8-10
Example 7 except that the blending ratio of PFA pellet 2, hexafluoroisobutylene / VdF alternating copolymer powder, PTFE powder 1 (number average molecular weight: 400,000, melting point 327 ° C.) was changed to the ratio shown in Table 1. The fluororesin composition was obtained by the method. The evaluation results for the obtained composition are shown in Table 1.

Example 11
Instead of PFA powder, FEP pellets (pellet shape: disk shape, average outer diameter 2.9 mmφ, average thickness: 1.7 mmt, melting point: 256 ° C., MFR: 23 g / 10 min, TFE / HFP: 90.9 A fluororesin composition was obtained in the same manner as in Example 1 except that /9.1 (mol%) was used. The evaluation results for the obtained composition are shown in Table 1.

Comparative Examples 1-3
The evaluation results for each of PFA pellets 1 to 3 are shown in Table 2.

Comparative Example 4
Table 2 shows the evaluation results of the hexafluoroisobutylene / VdF copolymer powder alone.

Comparative Example 5
Fluorine in the same manner as in Example 1 except that PTFE powder 2 (melting point: 327 ° C., average particle size: 6 μm, number average molecular weight: 20 million or more) was used in place of the hexafluoroisobutylene / VdF copolymer powder. A resin composition was obtained. The evaluation results for the obtained composition are shown in Table 2.

The present invention provides a fluororesin composition having a greatly improved elastic modulus at high temperatures. The present invention also provides a molded product such as a chemical solution tube comprising the fluororesin composition and a method for producing the fluororesin composition.

Claims (7)

A melt-processable fluororesin, and a copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and vinylidene fluoride having a melting point of 310 to 360 ° C. Fluororesin composition. The fluororesin composition according to claim 1, wherein the melt-processable fluororesin is a tetrafluoroethylene / hexafluoropropylene copolymer or a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer. The fluororesin composition according to claim 2, wherein the melt-processable fluororesin is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer. The copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and vinylidene fluoride is 8 to 70 parts by weight with respect to 100 parts by weight of a melt-processable fluororesin solid content. The fluororesin composition in any one of -3. Furthermore, the fluororesin composition in any one of Claims 1-4 containing polytetrafluoroethylene. The chemical | medical solution tube obtained by shape | molding the fluororesin composition in any one of Claims 1-5. A fluororesin comprising a melt-processable fluororesin and a step of melt-kneading a copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and vinylidene fluoride at a temperature equal to or higher than the melting point of both A method for producing the composition.