JP5051517B2 - Ethylene / tetrafluoroethylene copolymer composition - Google Patents

Description

  The present invention relates to an ethylene / tetrafluoroethylene copolymer composition having excellent mechanical properties and melt fluidity.

  An ethylene / tetrafluoroethylene copolymer (hereinafter also referred to as “ETFE”) is excellent in heat resistance, weather resistance, electrical insulation, non-adhesiveness, water and oil repellency, etc. It is characterized by high moldability and mechanical strength. Therefore, a wide range of molded products such as pump casings, diaphragm casings, fittings, packing, tubes, covered electric wires, sheets, films, linings, coatings, filaments, etc., by melt molding methods such as injection molding, extrusion molding, blow molding, etc. Are being produced, but there is a need for further expansion of applications.

  In response to the expansion of such applications, ETFE is required when high moldability is required, such as when injection molding or extrusion molding is performed at a higher speed, or when processing into a molded article having a very fine shape. It is necessary to further increase the melt fluidity of the resin.

  In addition, various fillers, pigments, and additives can be blended and filled as necessary to improve the strength, dimensional stability, imparting electrical conductivity, electromagnetic wave shielding properties, surface properties, coloring, etc. of molded products. Although it is desirable, when a filler or the like is highly blended / filled in conventional ETFE, there is a problem that the melt viscosity becomes high and the moldability deteriorates.

  Furthermore, when ETFE is impregnated with a fibrous material or inorganic porous material made of non-woven fabric, glass fiber, carbon fiber, aramid fiber, ceramics, or the like, a composite material such as a tent film or a porous printed board is used. In order to easily and surely impregnate even the pores, it is necessary to have high melt fluidity.

  Conventionally, regarding ETFE, if the molecular weight is lowered in order to increase the melt fluidity, there has been a problem that the heat resistance and mechanical properties of the obtained molded article are lowered. In particular, the decrease in the tensile elongation of the ETFE molded product due to the lowering of the molecular weight is a major obstacle to expanding the applications of the molded product.

  On the other hand, a method of improving the moldability by reducing the melt viscosity by blending high molecular weight ETFE (a) and low molecular weight ETFE (b) is known (see Patent Document 1). The melt fluidity of ETFE actually obtained is about 4200 to 4500 Pa · s. When higher melt fluidity is required, this level of fluidity is not sufficient.

JP 2000-212365 A (Claims (Claims 1 and 2), [0020] to [0035], Examples, Table 1)

  An object of the present invention is to provide an ethylene / tetrafluoroethylene copolymer composition having high melt flowability while maintaining the mechanical properties of a molded body, which is required to be developed under the background as described above. Is to provide.

  According to the present invention, an ethylene / tetrafluoroethylene copolymer composition having the following high melt fluidity is provided.

[1]
The melt viscosity at 240 ° C. is 80 to 300 Pa · s, the melting point is 120 to 240 ° C., the ethylene / tetrafluoroethylene copolymer (A), the melt viscosity at 240 ° C. is 1000 to 7000 Pa · s, the melting point Is a composition (C) comprising an ethylene / tetrafluoroethylene copolymer (B) having a mass ratio of (A) / (B) = 60/40 to 97/3. there, the melt viscosity of 80~500Pa · s, and a high melt flowability tensile elongation in ASTM D3159 is characterized in that 200 to 500% and a high tensile elongation ethylene / Tetrafluoroethylene copolymer composition (C).

[2]
The melt viscosity of the composition (C) is 100 to 350 Pa · s, and the tensile elongation is 250 to 450%. The ethylene / tetrafluoroethylene copolymer composition (C) according to [1] .

[3]
The melt viscosity of the composition (C) is 100 to 300 Pa · s, and the tensile elongation is 350 to 450%. The ethylene / tetrafluoroethylene copolymer composition (C) according to [1] .

[4]
The copolymer (A) and the copolymer (B) are contained in a mass ratio of (A) / (B) = 70/30 to 95/5, [1] to [3] Ethylene / tetrafluoroethylene copolymer composition (C).

  Moreover, according to this invention, the manufacturing method of the ethylene / tetrafluoroethylene copolymer composition which has the following high melt fluidity | liquidity is provided.

[5]
The ethylene according to any one of [1 ] to [4] , wherein the ethylene / tetrafluoroethylene copolymer (A) and the ethylene / tetrafluoroethylene copolymer (B) are melted and kneaded. / Method for producing tetrafluoroethylene copolymer composition (C).

  According to the present invention, mechanical properties such as tensile elongation of the molded body are substantially maintained while having high melt fluidity, for example, 10 times higher melt fluidity than conventional ones. An ethylene / tetrafluoroethylene copolymer composition is provided.

  Since the copolymer composition of the present invention has high melt fluidity without lowering the tensile elongation of the molded body as described above, this enables high-speed molding and production of a fine extruded molded body.

  In addition, since the ethylene / tetrafluoroethylene copolymer composition of the present invention has high melt flowability and extremely low melt viscosity, it is blended and filled with powder, fibrous fillers and pigments at high density. It is also suitable for the production of a composite, and because of its high melt fluidity, it can be easily impregnated into the inside of materials such as nonwoven fabrics, glass fibers, and carbon fibers.

Hereinafter, the present invention will be described in detail.
(Melt viscosity and tensile strength)
The ethylene / tetrafluoroethylene copolymer composition (C) of the present invention (hereinafter sometimes simply referred to as “ETFE composition” or “ETFE (C)”) basically has a melt viscosity of 80 to 500 Pa. It is a highly melt flowable ethylene / tetrafluoroethylene copolymer composition characterized by being s and having a tensile elongation of 200 to 500%. And preferably, the melt viscosity is 100 to 350 Pa · s, the tensile elongation is 250 to 450%, more preferably the melt viscosity is 100 to 300 Pa · s, and the tensile elongation is 350 to 350%. 450% is desirable.

  If the melt viscosity of the ETFE composition is within this range, high-speed extrusion molding and injection molding, thin-wall extrusion molding, injection molding, and press molding are possible, and further, impregnation into glass fibers and the like is also excellent. . Further, if the tensile elongation of the molded body is also within the above range, there is no practical problem as mechanical strength. On the other hand, if the tensile elongation is less than this, it becomes a brittle molded product, which is not practically preferable.

  The ETFE composition of the present invention basically includes ETFE (A) having a lower melt viscosity of 60 to 400 Pa · s and ETFE (B) having a higher melt viscosity of 600 to 10,000 Pa · s, It can be easily obtained by blending at a mass ratio of (A) / (B) = 50/50 to 99/1.

  And preferably, the melt viscosity of ETFE (A) is 80 to 300 Pa · s, and the melt viscosity of ETFE (B) is 1000 to 7000 Pa · s. If the melt viscosity of (A) or (B) is too high, sufficient melt fluidity cannot be obtained. On the other hand, if the melt viscosity is too low, the resulting molded article has insufficient tensile elongation.

  The blend ratio of (A) / (B) is preferably 60/40 to 97/3, more preferably 70/30 to 95/5. When the blend ratio exceeds or is less than the above specified value, the resulting ETFE composition has a melt viscosity of 80 to 500 Pa · s and a tensile elongation of 200 to 500%. It does not satisfy the characteristics.

(Measurement of melt viscosity)
The melt viscosity (melt fluidity) in the range of the present invention is preferably measured by a capillary fluidity measuring device (capillary rheometer). This is obtained by extruding molten resin at a constant speed, passing through a capillary, and measuring the stress required for extrusion. When the melt viscosity of ETFE is low, the molecular weight of the ETFE is low, and when the melt viscosity is high, the molecular weight of the ETFE is high.

  The melt fluidity of ETFE in the present invention is set, for example, as described in Examples below, by setting an orifice having a diameter of 1 mm and a length of 10 mm in a melt fluidity measuring device “Capillograph” manufactured by Toyo Seiki Seisakusho Co., Ltd., and a cylinder temperature of 240 ° C. Measured at a piston speed of 10 mm / min.

  Here, the temperature at which ETFE is melted is preferably 5 to 30 ° C. higher than the melting point of the ETFE. When measured under conditions lower than this temperature, ETFE does not melt sufficiently, making measurement difficult. When measured under conditions higher than this temperature, the viscosity of ETFE is too low and molten ETFE flows out of the orifice in a short time. This makes measurement difficult.

(Melting point)
The melting point of ETFE in the present invention is preferably 120 to 280 ° C, more preferably 150 to 270 ° C, and most preferably 180 to 260 ° C.
The melting point of ETFE in the present invention was heated from room temperature to 300 ° C. at 10 ° C./min in an air atmosphere using a scanning differential thermal analyzer (DSC220CU, manufactured by Seiko Instruments Inc.) as shown in Examples below. It is obtained from the endothermic peak at the time.

(Copolymerization composition of ETFE)
ETFE contains a repeating unit based on ethylene (hereinafter sometimes referred to as “E”) and a repeating unit based on tetrafluoroethylene (hereinafter sometimes referred to as “TFE”), and the content ratio thereof. (Molar ratio) is preferably 80/20 to 20/80, more preferably 70/30 to 30/70, and most preferably 60/40 to 40/60.

If the molar ratio of (repeating unit based on E) / (repeating unit based on TFE) is extremely large, the heat resistance, weather resistance, chemical resistance, chemical solution permeation prevention, etc. of the ETFE may be reduced. If the molar ratio is extremely small, mechanical strength, melt moldability, and the like may decrease. When in this range, the ETFE is excellent in heat resistance, weather resistance, chemical resistance, chemical penetration prevention, mechanical strength, melt moldability, and the like.

  In addition to the repeating unit based on E and the repeating unit based on TFE, ETFE may include a repeating unit based on one or more other monomers as long as the essential characteristics are not impaired.

Other monomers include α-olefins such as propylene and butene; CH ₂ ═CX (CF ₂ ) _n Y (where X and Y are independently hydrogen or fluorine atoms, and n is an integer of 2 to 8) )); A fluoroolefin having a hydrogen atom in an unsaturated group such as vinylidene fluoride (VDF), vinyl fluoride (VF), trifluoroethylene, hexafluoroisobutylene (HFIB); hexafluoropropylene (HFP) ), Chlorotrifluoroethylene (CTFE), perfluoro (methyl vinyl ether) (PMVE), perfluoro (ethyl vinyl ether) (PEVE), perfluoro (propyl vinyl ether) (PPVE), perfluoro (butyl vinyl ether) (PBVE), Other perfluoro (alkyl vinyl ether) (PA E) fluoroolefin (but having no hydrogen atom in an unsaturated group such as, excluding TFE.), And the like. 1 type (s) or 2 or more types can be used for another monomer.

Among these other monomers, it is preferable to use a compound represented by the general formula CH ₂ = CX (CF ₂ ) _n Y (hereinafter referred to as “FAE”). As described above, FAE has the general formula CH ₂ = CX (CF ₂ ) _n Y (where X and Y are each independently a hydrogen atom or a fluorine atom, and n is an integer of 2 to 8). It is a compound represented. If n in the formula is less than 2, the properties of ETFE may be insufficient (for example, occurrence of stress cracks in the ETFE formed body). On the other hand, if n in the formula exceeds 8, the point of polymerization reactivity May be disadvantageous.

The _{FAE, CH 2 = CF (CF} 2) 2 F, CH 2 = CF (CF 2) 3 F, CH 2 = CF (CF 2) 4 F, CH 2 = CF (CF 2) 5 F, CH 2 _{= CF (CF 2) 8 F} , CH 2 = CF (CF 2) 2 H, CH 2 = CF (CF 2) 3 H, CH 2 = CF (CF 2) 4 H, CH 2 = CF (CF 2) ₅ H, CH ₂ = CF (CF ₂ ) ₈ H, CH ₂ = CH (CF ₂ ) ₂ F, CH ₂ = CH (CF ₂ ) ₃ F, CH ₂ = CH (CF ₂ ) ₄ F, CH ₂ = _{CH (CF 2) 5 F,} CH 2 = CH (CF 2) 8 F, CH 2 = CH (CF 2) 2 H, CH 2 = CH (CF 2) 3 H, CH 2 = CH (CF 2) 4 _{H, CH 2 = CH (CF} 2) 5 H, CH 2 = CH (CF 2) 8 H , and the like. 1 type (s) or 2 or more types can be used for FAE.

Among these, a compound represented by CH ₂ ═CH (CF ₂ ) _n Y is more preferable, and in this case, n in the formula is n = 2 to 6, so that the molded article has stress rack resistance. Since it is excellent, it is more preferable, and n = 2-4 is most preferable.

  The content of the repeating unit based on FAE in the ETFE composition is preferably 0.01 to 20 mol%, more preferably 0.1 to 15 mol% in all repeating units of the composition. More preferably, it is 1-10 mol%. If the content of FAE is less than the above value, the stress crack resistance of the molded body formed from the ETFE composition may be reduced, and a fracture phenomenon such as cracking may occur under stress. When it exceeds, the mechanical strength of the said composition may fall.

(Method for producing ETFE (A) and (B))
The method for producing ETFE (A) and ETFE (B) in the present invention includes (1) a method for adjusting the molecular weight during polymerization, and (2) a molecule obtained by applying energy such as heat and radiation to ETFE obtained by polymerization. (3) A method of producing ETFE molecular chains obtained by polymerization by chemically cleaving them with radicals, specifically melting ETFE and organic peroxide with an extruder There is a method of kneading and cutting the molecular chain of ETFE with generated radicals to lower the viscosity. In principle, any of the methods can be applied. However, in the case of the methods (2) to (3), an active functional group such as a carbonyl group is generated at the cleavage site in ETFE, resulting in undesirable adhesiveness. There are problems that are likely to occur. Therefore, it is most preferable because such an active functional group is not generated in ETFE obtained by the method (1) and productivity is high.

  The method for producing ETFE (A) and (B) in the present invention is not particularly limited, and ethylene and tetrafluoroethylene are charged into a reactor, and generally used radical polymerization initiators and chain transfer agents are used. The method of copolymerization can be employed. Examples of polymerization methods include bulk polymerization, solution polymerization using fluorinated hydrocarbons, chlorinated hydrocarbons, fluorinated chlorohydrocarbons, alcohols, carbonized and hydrogenated organic solvents as polymerization media; polymerization media Suspension polymerization using an aqueous medium and, if necessary, an appropriate organic solvent; emulsion polymerization using an aqueous medium and an emulsifier as the polymerization medium may be mentioned, but in the presence of a radical polymerization initiator, a chain transfer agent, and a polymerization medium. Furthermore, solution polymerization in which ethylene and tetrafluoroethylene which are fluorine-containing monomers are copolymerized is most preferable. The polymerization can be carried out as a batch operation or a continuous operation using a one-tank or multi-tank stirring polymerization apparatus, a tube polymerization apparatus, or the like.

The radical polymerization initiator is preferably an initiator having a half-life of 10 hours and a temperature of 0 to 100 ° C, more preferably an initiator having a temperature of 20 to 90 ° C. For example, azo compounds such as azobisisobutyronitrile; peroxydicarbonates such as diisopropylperoxydicarbonate; peroxyesters such as tert-butylperoxypivalate, tert-butylperoxyisobutyrate, tert-butylperoxyacetate; Non-fluorinated diacyl peroxides such as ril peroxide, octanoyl peroxide, benzoyl peroxide, lauroyl peroxide; (Z (CF ₂ ) _p COO) ₂ (where Z is a hydrogen atom, a fluorine atom or a chlorine atom, and p is 1 And fluorine-containing diacyl peroxides; inorganic peroxides such as potassium persulfate, sodium persulfate, and ammonium persulfate.

  Examples of the polymerization medium include organic solvents such as fluorinated hydrocarbons, chlorinated hydrocarbons, fluorinated chlorinated hydrocarbons, alcohols and hydrocarbons, and aqueous media as described above.

  Examples of chain transfer agents include alcohols such as methanol and ethanol; chlorofluorohydrocarbons such as 1,3-dichloro-1,1,2,2,3-pentafluoropropane and 1,1-dichloro-1-fluoroethane; Examples thereof include hydrocarbons such as pentane, hexane, and cyclohexane. The addition amount of the chain transfer agent is usually about 0.01 to 100% by mass with respect to the polymerization medium. By adjusting the concentration of the chain transfer agent, the melt viscosity (molecular weight) of the obtained ETFE can be adjusted. That is, the higher the chain transfer agent concentration, the lower the molecular weight ETFE.

  In particular, when producing a low molecular weight ethylene / tetrafluoroethylene copolymer (A) preferably used in the present invention, 1,3-dichloro-1,1,2,2,3- usually used as a chain transfer agent. It is also preferred to use pentafluoropropane as the polymerization medium.

  The polymerization conditions are not particularly limited, but the polymerization temperature is usually preferably 0 to 100 ° C and more preferably 20 to 90 ° C. The polymerization pressure is preferably from 0.1 to 10 MPa, more preferably from 0.5 to 3 MPa. The higher the polymerization pressure is in the above range, the higher the polymer obtained and the higher the melt viscosity. Therefore, the melt viscosity can be adjusted by adjusting the polymerization pressure. The polymerization time may vary depending on the polymerization temperature, polymerization pressure, etc., but is usually preferably 1-30 hours, more preferably 2-10 hours.

The amount of ETFE relative to the polymerization medium at the end of the polymerization reaction is usually about 0.03 to 0.2 g / cm ³ , but the molecular weight of ETFE can be adjusted by this concentration. That is, the lower the ETFE concentration in the above range, the lower the molecular weight ETFE can be obtained.

(Blend of ETFE (A) and (B))
In the present invention, the forms of ETFE (A) and ETFE (B) are not particularly limited, and may be any of pellets, beads, powders, crumbs, and the like. In addition, ETFE (C) can be obtained by blending them, and most preferably, a single-screw or twin-screw extruder is used, and ETFE (A) and (B) are added at a desired mass ratio. It is charged and melted, and both resins are sufficiently melt-kneaded. The ETFE (C) thus obtained is preferably in the form of pellets, for example.

(Filler etc.)
The ETFE composition of the present invention can be made into a composite containing the following fillers, fillers, pigments and the like in order to develop various properties. For example, fiber reinforcing materials such as carbon fiber, glass fiber, and aramid fiber; dimensional stability imparting materials such as glass beads; carbon black, carbon nanotube, fluorinated CNT, stannic oxide, black titanate, titanate whisker, etc. Conductive or semiconductive fillers; Transparent conductivity imparting agents such as ionic liquids; Various whisker / potassium titanate, aluminum borate, carbon whiskers, calcium carbonate whiskers, etc .; graphite, magnesium oxide, low melting point Materials for imparting thermal conductivity such as metals and metal fibers; Materials for imparting slidability such as PTFE lubricants; Electromagnetic wave shielding materials such as ferrite and metals; Low gas permeation and reinforcing materials such as nanoclay, fluorinated organically treated nanoclay and talc; Light weight materials such as glass balloons, various elastomers, fluoro rubber, etc. Flexibility imparting material; High strength imparting material such as nylon and aramid; Titanium oxide, zinc oxide, carbon black, copper / chromium black, molybdate orange, iron oxide, yellow lead, yellow iron oxide, titanium yellow, titanium antimony, Color pigments such as chrome yellow, chrome green, chrome oxide green, cobalt green; and further, crosslinking agents and crosslinking aids such as crystal nucleating agent and triallyl isocyanurate, foaming agent, foaming core material, heat stabilizer copper, copper Additives such as compounds (copper oxide, copper iodide, etc.), antioxidants, light stabilizers, ultraviolet absorbers can be used in combination.

  Since the ETFE composition of the present invention has an extremely low melt viscosity, an ETFE composite in which the above-mentioned various particulate and fibrous fillers and pigments are blended and filled at a high density without impairing moldability. It can be a body. In addition, since the ETFE composition has high melt fluidity, it can be easily impregnated into a material such as a porous body made of nonwoven fabric, glass fiber, aramid fiber, carbon fiber, or ceramics.

(Molded body)
The ETFE composition of the present invention can be easily molded by various molding methods such as injection molding, extrusion molding, blow molding, compression molding, inflation molding, transfer molding, etc., to obtain a desired molded body. The molded body obtained from the ETFE composition of the present invention is a membrane structure member such as a pump casing, a diaphragm valve casing, a fitting, a packing, a sealing member, a tube, a covered electric wire, a sheet, a film, a lining, a coating, a filament, and a tent film. And a wide range of fields such as printed circuit boards.

  Hereinafter, the present invention will be specifically described with reference to examples, but the technical scope of the present invention is not limited thereto. The melt viscosity, composition, melting point, and tensile elongation of ETFE were measured by the following methods.

[Measurement of melt viscosity (Pa · s)]
An orifice with a diameter of 1 mm and a length of 10 mm is set in a melt fluidity measuring device “Capillograph” manufactured by Toyo Seiki Seisakusho Co., Ltd. Extruded ETFE is melted at a cylinder temperature of 240 ° C. and a piston speed of 10 mm / min, and the melt viscosity is measured. did.

[Polymer composition (mol%)]
It calculated from the result of the total fluorine amount measurement, and the melt | dissolution ¹⁹ F-NMR measurement.

[Melting point (℃)]
It calculated | required from the endothermic peak at the time of heating at 10 degree-C / min from room temperature to 300 degreeC in an air atmosphere using the scanning differential thermal analyzer (the Seiko Instruments company make, DSC220CU).

[Tensile elongation (%)]
It was measured by the method described in ASTM D3159. As a sample, a sheet having a thickness of 1 mm was prepared by a hot press, and a test piece was cut out. The tensile speed was measured at 50 mm / min.

[Synthesis Example 1]
(1) A polymerization tank equipped with a stirrer having an internal volume of 94 liters is degassed, and 1,3-dichloro-1,1,2,2,3-pentafluoropropane (AK225cb manufactured by Asahi Glass Co., Ltd., hereinafter referred to as “AK225cb”). ) 87.3 kg, charged with 860 g of CH ₂ = CH (CF ₂ ) ₄ F, the temperature inside the polymerization tank was raised to 66 ° C. with stirring, and a mixed gas of TFE / E = 89/11 (molar ratio) was polymerized. The reactor was introduced until the pressure of the tank reached 1.4 MPaG, and 677 g of a 1% by mass AK225cb solution of tert-butylperoxypivalate was charged as a polymerization initiator to initiate polymerization. CH ₂ = CH (CF ₂ ) ₄ F at a ratio corresponding to 3.3 mol% with respect to the mixed gas of composition TFE / E = 60/40 (molar ratio) and the mixed gas so that the pressure becomes constant during the polymerization. Was continuously charged. 8 hours after the start of polymerization, when 7.1 kg of the monomer mixed gas was charged, the temperature in the polymerization tank was lowered to room temperature and purged to normal pressure.

(2) The obtained slurry-like ETFE was put into a 200 L granulation tank charged with 77 kg of water, and then heated to 105 ° C. while stirring to granulate while distilling off and removing the solvent. The obtained granulated product was dried at 150 ° C. for 5 hours to obtain 7.0 kg of sample ETFE (hereinafter referred to as “ETFE1” (= ETFE (A))).

The polymer composition of ETFE1 is as follows: repeating unit based on TFE / repeating unit based on E / repeating unit based on CH ₂ ═CH (CF ₂ ) ₄ F = 57.3 / 40.4 / 2.4 mol%, The melting point was 223 ° C. and the melt viscosity was 120 Pa · s.

[Synthesis Example 2]
(1) A polymerization tank equipped with a stirrer with an internal volume of 1.3 liters was degassed and charged with 1154.5 g of AK225cb and 10.9 g of CH ₂ ═CH (CF ₂ ) ₄ F, and 163 g of TFE with stirring. , 5.6 g of E was introduced, the temperature in the polymerization tank was raised to 66 ° C., and 7.5 g of a 4 mass% AK225cb solution of tert-butylperoxypivalate was charged as a polymerization initiator at a pressure of 1.36 MPaG. The polymerization was started. CH ₂ = CH (CF ₂ ) ₄ F at a ratio corresponding to 3.3 mol% with respect to the mixed gas of composition TFE / E = 60/40 (molar ratio) and the mixed gas so that the pressure becomes constant during the polymerization. Was continuously charged. After 4.2 hours from the start of polymerization, when 100 g of the monomer mixed gas was charged, the temperature in the polymerization tank was lowered to room temperature and purged to normal pressure.

(2) The obtained slurry-like ETFE was suction filtered with a glass filter, ETFE and the solvent were separated, and the obtained ETFE was dried at 150 ° C. for 12 hours to obtain a sample ETFE (hereinafter referred to as “ETFE2” (hereinafter referred to as “ETFE2”). = ETFE (A)).

The polymer composition of ETFE2 is TFE based repeating units / E based repeating units / CH ₂ ═CH (CF ₂ ) ₄ F based repeating units = 57.4 / 40.6 / 2.0 mol%, and The melting point was 230 ° C., and the melt viscosity was 224 Pa · s.

[Synthesis Example 3]
(1) Instead of AK225cb described in Synthesis Example 2, 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane (hereinafter referred to as “C6H”) 1208 g, 10.9 g of CH ₂ ═CH (CF ₂ ) ₄ F, and 12.81 g of CH ₂ ═CH (CF ₂ ) ₄ F, and 16.5 g of methanol were charged, and tert− Polymerization was carried out in the same manner as in Synthesis Example 2 except that 7.5 g of a 4% by mass AK225cb solution of butyl peroxypivalate was changed to 5.7 ml of a 4% by mass C6H solution of tert-butyl peroxypivalate. 3.3 hours after the start of polymerization, when 90 g of the monomer gas was charged, the temperature in the polymerization tank was lowered to room temperature and purged to normal pressure.

(2) The slurry-like ETFE obtained is transferred to a 1.5-liter flask together with 300 ml of water, ETFE and the solvent are separated by a rotary evaporator, and the obtained ETFE is dried at 150 ° C. for 12 hours. Sample ETFE (hereinafter referred to as “ETFE5” (= ETFE (A))) was obtained.

(3) The polymer composition of ETFE5 is a repeating unit based on TFE / a repeating unit based on E / a repeating unit based on CH ₂ ═CH (CF ₂ ) ₄ F = 54.6 / 42.0 / 3.4 mol%. The melting point was 232 ° C. and the melt viscosity was 166 Pa · s.

[Reference Example 1]
General ETFE (manufactured by Asahi Glass Co., Ltd., trade name: FLUON LM ETFE · LM-720, melting point: 228 ° C., melt viscosity: 2587 Pa · s, tensile strength: 44 MPa, tensile elongation 42: 6% (hereinafter referred to as “ETFE3”) (= ETFE (B))) was used as a reference sample.

[Example 1]
ETFE1 (= ETFE (A)) and ETFE3 (= ETFE (B)) were mixed at a ratio of ETFE1 / ETFE3 = 90/10 (mass ratio), and using a single screw extruder (manufactured by Tanabe Plastics, φ20 mm). The mixture was melt-kneaded to obtain pellet-like ETFE4 (= ETFE (C)).
ETFE4 had a melt viscosity of 228 Pa · s, a tensile strength of 23 MPa, and a tensile elongation of 372%.

[Example 2]
ETFE5 (= ETFE (A)) and ETFE3 (= ETFE (B)) are mixed at a ratio of ETFE5 / ETFE3 = 90/10 (mass ratio), and melt kneaded using a Laboplast mill (manufactured by Toyo Seiki Seisakusho). Thus, massive ETFE6 (= ETFE (C)) was obtained. The kneading conditions were 240 ° C. and 100 rpm for 10 minutes.
ETFE6 had a melt viscosity of 322 Pa · s, a tensile strength of 22 MPa, and a tensile elongation of 294%.

[Comparative Example 1]
ETFE1 had a tensile strength of 19 MPa and a tensile elongation of 172%.

[Comparative Example 2]
ETFE2 had a tensile strength of 20 MPa and a tensile elongation of 147%.

[Comparative Example 3]
ETFE5 had a tensile strength of 22 MPa and a tensile elongation of 92%.
The above results are summarized in Table 1.

  As is apparent from Table 1, the ETFE compositions of the present invention (Examples 1 and 2) have a low melt viscosity of 228 Pa · s and 322 Pa · s, high melt flowability, and a high tensile elongation. 372%, 294%, and this characteristic is much less than the tensile elongation (426%) of the general ETFE of Reference Example 1 (melting viscosity is 2587 Pa · s, which is an order of magnitude higher than this). It is noted that it has not declined significantly. This is because, for example, in ETFE 2 of Comparative Example 2, the melt viscosity is as low as that of Example 1 (224 Pa · s), but its tensile elongation is greatly reduced to 147%, which is very brittle. There is a great contrast. Further, Comparative Examples 1 and 3 have lower melt viscosities, but the tensile elongation is still insufficient.

  As is clear from Table 1, the ETFE composition of the present invention (Example 1, ETFE4) has a low melt viscosity of 228 Pa · s and a high melt fluidity, while the tensile elongation is 372%, It is noteworthy that this characteristic is not so much lower than the tensile elongation (426%) of the general ETFE of Reference Example 1 (2587 Pa · s whose melt viscosity is one digit higher than this). Is done. This is because, for example, in ETFE 2 of Comparative Example 2, the melt viscosity is as low as that of Example 1 (224 Pa · s), but its tensile elongation is greatly reduced to 147%, which is very brittle. There is a great contrast.

  The ETFE composition of the present invention has a high melt fluidity such as a low melt viscosity of 80 to 500 Pa · s, but a tensile elongation of 200 to 500%, which is much lower than the tensile elongation of ETFE, which has a single digit higher melt viscosity. Not done. Therefore, it is possible to manufacture an extrusion molded body or an injection molded body with high productivity, and it is suitable for manufacturing a fine extrusion molded body or an injection molded body.

  In addition, since the ETFE composition of the present invention has an extremely low melt viscosity, it is possible to sufficiently disperse powders, fibrous fillers, pigments, and the like of metal materials, inorganic materials, and organic materials in a molten state. It is also suitable for the production of ETFE composites containing and filling these fillers at high density.

  Furthermore, since the ETFE composition of the present invention has a high melt fluidity, it is a non-woven fabric, a glass fiber, an aramid fiber, a carbon fiber, a porous material made of ceramics, or a plastic material such as polyethylene, polyvinylidene fluoride, polyethylene, etc. The porous body made of can be easily impregnated to the inside in a molten state.

Claims (5)

The melt viscosity at 240 ° C. is 80 to 300 Pa · s, the melting point is 120 to 240 ° C., the ethylene / tetrafluoroethylene copolymer (A), the melt viscosity at 240 ° C. is 1000 to 7000 Pa · s, the melting point Is a composition (C) comprising an ethylene / tetrafluoroethylene copolymer (B) having a mass ratio of (A) / (B) = 60/40 to 97/3. there, the melt viscosity of 80~500Pa · s, and a high melt flowability tensile elongation in ASTM D3159 is characterized in that 200 to 500% and a high tensile elongation ethylene / Tetrafluoroethylene copolymer composition (C). 2. The ethylene / tetrafluoroethylene copolymer composition (C) according to claim 1, wherein the melt viscosity of the composition (C) is 100 to 350 Pa · s and the tensile elongation is 250 to 450%. . 2. The ethylene / tetrafluoroethylene copolymer composition (C) according to claim 1, wherein the melt viscosity of the composition (C) is 100 to 300 Pa · s and the tensile elongation is 350 to 450%. . The ethylene / copolymer according to any one of claims 1 to 3, which contains the copolymer (A) and the copolymer (B) at a mass ratio of (A) / (B) = 70/30 to 95/5. Tetrafluoroethylene copolymer composition (C). The ethylene / tetrafluoroethylene copolymer (A) and the ethylene / tetrafluoroethylene copolymer (B) are melted and kneaded, according to any one of claims 1 to 4. A method for producing a fluoroethylene copolymer composition (C).