Injection molded body, liner, and liner valve

Abstract

The present invention provides an injection-molded article comprising: a tube portion forming a flow path for a fluid; and a flange portion formed at one or both ends of the tube portion, wherein the maximum thickness of the flange portion is 2 mm to 12 mm, the injection-molded article contains a copolymer, the copolymer containing tetrafluoroethylene units and fluorinated (alkyl vinyl ether) units, the content of fluorinated (alkyl vinyl ether) units in the copolymer being 2.8% to 6.0% by mass relative to all monomer units, the melt flow rate of the copolymer at 372°C being 4.0 g / 10 min or more and less than 11.0 g / 10 min, and the number of functional groups in the copolymer being 50 or less.

Description

Technical Field

[0001] This invention relates to injection molded bodies, liners, and lined valves. Background Technology

[0002] Patent document 1 describes a liner in which a bushing is provided on the inner circumferential surface and the flange surface of the conduit.

[0003] Patent document 2 describes a method where a cylindrical core is inserted into the hollow portion of a cylindrical article, resin is injected into the gap between the article and the core, and after the resin cools and solidifies, the core is removed, thereby lining the inner surface of the cylindrical article. In this method, the resin used has a melt viscosity of 1 to 7 × 10⁻⁶ at 372°C. 5 Po's perfluorocarbon resin.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 58-132512

[0007] Patent Document 2: Japanese Patent Publication No. 01-053167 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The purpose of this invention is to provide an injection molded body having a tube body and a thick flange, which can suppress wear on the inner surface of the tube body and reduce the sealing performance of the flange even when used in a high-temperature environment.

[0010] Methods for solving problems

[0011] According to the present invention, an injection-molded article is provided, comprising: a tube portion forming a flow path for a fluid; and a flange portion formed at one or both ends of the tube portion, wherein the maximum thickness of the flange portion is 2 mm to 12 mm, the injection-molded article contains a copolymer, the copolymer containing tetrafluoroethylene units and fluorinated (alkyl vinyl ether) units, the content of fluorinated (alkyl vinyl ether) units in the copolymer being 2.8% to 6.0% by mass relative to all monomer units, the melt flow rate of the copolymer at 372°C being 4.0 g / 10 min or more and less than 11.0 g / 10 min, and the number of functional groups in the copolymer being 50 or less.

[0012] The fluorinated (alkyl vinyl ether) unit of the copolymer is preferably a perfluoro (propyl vinyl ether) unit.

[0013] The content of the fluorinated (alkyl vinyl ether) unit in the copolymer is preferably 3.5 to 5.5% by mass relative to all monomer units.

[0014] The melt flow rate of the copolymer at 372°C is preferably 5.0 to 9.0 g / 10 min.

[0015] The preferred melting point of the copolymer is 295–315°C.

[0016] Preferably, it is a lining component of a liner or a lined valve.

[0017] In addition, according to the present invention, a liner is provided, the contact surface of which with the fluid is lined by the injection-molded body described above.

[0018] In addition, according to the present invention, a lined valve is provided, wherein the contact surface with the fluid is lined by the injection-molded body described above.

[0019] Invention Effects

[0020] According to the present invention, an injection molded body is provided, which is an injection molded body having a tube portion and a flange portion with a large thickness, which can suppress wear on the inner surface of the tube portion and reduce the sealing performance of the flange portion even when used in a high temperature environment. Attached Figure Description

[0021] Figure 1 This is a schematic cross-sectional view illustrating one embodiment of using the injection-molded body of the present invention as a liner for lining the inner surface. Detailed Implementation

[0022] The following describes specific embodiments of the present invention in detail, but the present invention is not limited to the following embodiments.

[0023] Traditionally, to prevent corrosion and scale buildup in pipes or valves, lined pipes or valves with fluoropolymer bushings on their inner surfaces are used. Injection molding and rotational molding are known methods for applying fluoropolymer bushings to pipes or valves. Among these methods, injection molding has advantages such as the ability to easily form relatively thick bushings and the smoother inner surface of the resulting injection-molded body. Furthermore, when the bushing has a flange, it also has advantages in that the pipe body and flange can be integrally molded, and in that it is easy to form flanges with greater thickness and higher mechanical strength.

[0024] However, conventional liners and lined valves using injection molding to line fluororesin have the following problems: the inner surface wears due to the passage of high-temperature fluid containing solid particles, or the flange, which is fastened in a high-temperature environment, gradually deforms, resulting in insufficient sealing. With a large flange thickness, even with the same proportional change, a larger gap is generated compared to a thinner flange, thus the sealing performance of the flange with the larger thickness is easily reduced. Therefore, a technology is required that increases the flange thickness to ensure strength that prevents breakage even under impact, and that suppresses wear on the inner surface of the tube body and reduction in flange sealing performance even under high-temperature conditions.

[0025] The injection-molded article of the present invention comprises: a tube portion forming a flow path for fluid; and a flange portion formed at one or both ends of the tube portion, wherein the maximum thickness of the flange portion is 2 mm to 12 mm. Therefore, the flange portion of the injection-molded article of the present invention has sufficient strength and is not easily damaged by impact, etc. Furthermore, the tube portion and the flange portion are formed using a copolymer with a FAVE unit content, melt flow rate (MFR), and number of functional groups within extremely limited ranges, wherein the copolymer is a copolymer containing tetrafluoroethylene (TFE) units and fluorinated (alkyl vinyl ether) (FAVE) units. As a result, the wear resistance of the tube portion is improved, and the reduction in the sealing performance of the flange portion, which is particularly problematic when the flange portion is thick, is also suppressed.

[0026] An embodiment of a liner using the injection-molded body 100 of the present invention is shown as a liner member for lining the inner surface. Figure 1 . Figure 1 The liner shown includes a liner member 1 and a tube body 2 that is lined by the liner member 1. The liner member 1 includes a tube body portion 11 that forms a flow path for fluid and flange portions 12 formed at both ends of the tube body portion 11. The liner member 1 has flange portions 12 at both ends, but it may also have a flange portion 12 at only one end.

[0027] The liner 1 is an injection-molded body integrally formed from the flange portion 12 and the tube body portion 11. Generally, the flange portion 12 is connected to the flange portions of other tubes or valves by means of a sealing gasket.

[0028] In the injection-molded article of the present invention, the maximum thickness of the flange portion 12 is 2 mm to 12 mm. This increases the maximum thickness of the flange portion 12, making it less prone to breakage even under impact. If the flange portion 12 is too thick, the sealing performance of the connection portion is easily reduced. However, the injection-molded article of the present invention is formed from a copolymer with a very limited range of FAVE unit content, MFR, and functional group number, so the sealing performance is not easily reduced even under continuous use at high temperatures. If the flange portion thickness is too small, the mold thickness also becomes small, making it difficult to fill the mold with the copolymer, and it is impossible to obtain an injection-molded article with a flange portion having the desired shape. If the flange portion thickness is too large, molding defects called voids are easily generated during injection molding, and the flange portion is prone to breakage.

[0029] exist Figure 1 In the injection-molded article 100 shown, the thickness of the flange portion 12 is uniform, but the thickness can also be varied in a range of 2 mm to 12 mm. In one embodiment, the overall thickness of the flange portion 12 can also be in the range of 2 mm to 12 mm. The maximum thickness of the flange portion 12 is preferably 3 mm or more, preferably 10 mm or less, and more preferably 8 mm or less.

[0030] To line the inner surface of the tube body 2, the tube body portion 11 of the injection-molded body 100 is cylindrical, just like the tube body 2. The shape of the tube body portion 11 is not limited to cylindrical; it can be a shape that matches the shape of the object being lined. For example, the shape of the tube body portion 11 can be cylindrical, square, spherical, etc. Furthermore, the tube body portion 11 can be curved or branched.

[0031] The thickness of the tube portion 11 of the injection molded body 100 is not particularly limited, for example, it can be 0.1 to 100 mm.

[0032] The injection-molded articles of the present invention contain a copolymer comprising tetrafluoroethylene (TFE) units and fluorinated (alkyl vinyl ether) (FAVE) units. This copolymer is a melt-processable fluoropolymer. Melt processability refers to the ability to melt and process the polymer using existing processing equipment such as extruders and injection molding machines.

[0033] As a FAVE constituting the above-mentioned FAVE unit, at least one of the groups consisting of the monomers shown in general formula (1) and the monomers shown in general formula (2) can be listed.

[0034] General formula (1):

[0035] CF2=CFO(CF2CFY 1 O) p -(CF2CF2CF2O) q-Rf (1)

[0036] (where Y) 1 (This indicates F or CF3, Rf indicates a perfluoroalkyl group with 1 to 5 carbon atoms, p indicates an integer from 0 to 5, and q indicates an integer from 0 to 5.)

[0037] General formula (2):

[0038] CFX=CXOCF2OR 1 (2)

[0039] (In the formula, X being the same or different represents H, F, or CF3, R) 1 This refers to a straight-chain or branched fluoroalkyl group having 1 to 6 carbon atoms and containing 1 to 2 atoms selected from the group consisting of H, Cl, Br, and I; or a cyclic fluoroalkyl group having 5 or 6 carbon atoms and containing 1 to 2 atoms selected from the group consisting of H, Cl, Br, and I.

[0040] Among them, the monomer represented by general formula (1) is preferred as the FAVE, more preferably at least one of the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether) (PEVE) and perfluoro(propyl vinyl ether) (PPVE), further preferably at least one of the group consisting of PEVE and PPVE, and particularly preferably PPVE.

[0041] The content of FAVE units in the copolymer is 2.8 to 6.0% by mass relative to all monomer units. More preferably, the content of FAVE units in the copolymer is 3.0% by mass or more, further preferably 3.2% by mass or more, even more preferably 3.3% by mass or more, particularly preferably 3.4% by mass or more, most preferably 3.5% by mass or more, more preferably 5.8% by mass or less, even more preferably 5.6% by mass or less, and even more preferably 5.5% by mass or less. If the content of FAVE units in the copolymer is too high, it is insufficient to suppress wear on the inner surface of the tube body caused by high-temperature fluid flow. If the content of FAVE units in the copolymer is too low, the sealing performance of the flange portion decreases when used at high temperatures.

[0042] The content of TFE units in the copolymer is preferably 94.0 to 97.2% by mass relative to all monomer units, more preferably 94.2% by mass or more, further preferably 94.4% by mass or more, even more preferably 94.5% by mass or more, more preferably 97.0% by mass or less, further preferably 96.8% by mass or less, even more preferably 96.7% by mass or less, particularly preferably 96.6% by mass or less, and most preferably 96.5% by mass or less. If the content of TFE units in the copolymer is too low, it may not be able to adequately suppress wear on the inner surface of the tube body caused by high-temperature fluid flow. If the content of TFE units in the copolymer is too high, the sealing performance of the flange may decrease when used at high temperatures.

[0043] In this invention, the content of each monomer unit in the copolymer is determined by... 19 Determined by F-NMR method.

[0044] The copolymer may also contain monomer units from monomers capable of copolymerizing with TFE and FAVE. In this case, the content of monomer units capable of copolymerizing with TFE and FAVE is preferably 0% to 3.2% by mass, more preferably 0.05% to 1.0% by mass, and even more preferably 0.1% to 0.3% by mass, relative to all monomer units of the copolymer.

[0045] Monomers capable of copolymerizing with TFE and FAVE include hexafluoropropylene (HFP) and CZ. 1 Z 2 =CZ 3 (CF2) n Z 4 (where Z) 1 Z 2 and Z 3 Same or different, represented by H or F, Z 4 Vinyl monomers (represented by H, F, or Cl, where n represents an integer from 2 to 10) and CF2=CF-OCH2-Rf 1 (where Rf) 1 This refers to perfluoroalkyl groups having 1 to 5 carbon atoms. Alkyl perfluorovinyl ether derivatives, etc., are also included. HFP is preferred.

[0046] The copolymer is preferably selected from at least one of the groups consisting of copolymers composed only of TFE units and FAVE units and TFE / HFP / FAVE copolymers, and more preferably copolymers composed only of TFE units and FAVE units.

[0047] The melt flow rate (MFR) of the copolymer is 4.0 g / 10 min or more and less than 11.0 g / 10 min. The MFR of the copolymer is preferably 4.5 g / 10 min or more, more preferably 5.0 g / 10 min or more, preferably 10.5 g / 10 min or less, more preferably 10.0 g / 10 min or less, further preferably 9.5 g / 10 min or less, and particularly preferably 9.0 g / 10 min or less. If the MFR is too low, an injection-molded body with a flange portion having the desired thickness cannot be obtained. If the MFR of the copolymer is too high, wear on the inner surface of the tube portion caused by high-temperature fluid flow cannot be adequately suppressed; furthermore, the sealing performance of the flange portion decreases when used at high temperatures.

[0048] In this invention, MFR is a value obtained according to ASTM D1238 using a melt index meter in the form of the mass (g / 10 min) of polymer flowing out of a nozzle with an inner diameter of 2.1 mm and a length of 8 mm every 10 minutes at 372°C and a load of 5 kg.

[0049] MFR can be adjusted by modifying the type and amount of polymerization initiator and the type and amount of chain transfer agent used in monomer polymerization.

[0050] In this invention, every 10 of the copolymer 6 The number of functional groups per carbon atom in the main chain is 50 or less, preferably 40 or less, more preferably 30 or less, further preferably 20 or less, even more preferably 15 or less, particularly preferably 10 or less, and most preferably less than 6. If the copolymer has too many functional groups, the sealing performance of the flange will decrease when used at high temperatures.

[0051] The identification of the types of functional groups and the determination of the number of functional groups mentioned above can be achieved using infrared spectroscopy.

[0052] Regarding the number of functional groups, specifically, it was determined using the following method. First, the above copolymer was cold-pressed to produce a film with a thickness of 0.25 mm to 0.3 mm. The film was analyzed by Fourier transform infrared spectroscopy to obtain the infrared absorption spectrum of the above copolymer, and a differential spectrum was obtained compared with the background spectrum of a fully fluorinated copolymer without functional groups. The number of functional groups in the above copolymer was calculated from the absorption peaks of specific functional groups shown in the differential spectrum according to the following formula (A). 6 The number of functional groups N per carbon atom.

[0053] N = I × K / t (A)

[0054] I: Absorbance

[0055] K: Correction coefficient

[0056] t: Membrane thickness (mm)

[0057] For reference, the absorption frequencies, molar absorptivity, and correction factors for some functional groups are shown in Table 1. Furthermore, the molar absorptivity was determined using FT-IR measurements of low-molecular-weight model compounds.

[0058] [Table 1]

[0059]

[0060] The absorption frequencies of -CH2CF2H, -CH2COF, -CH2COOH, -CH2COOCH3, and -CH2CONH2 are tens of Kaiser (cm) lower than those of -CF2H, -COF, free -COOH, and bonded -COOH, -COOCH3, and -CONH2, respectively, as shown in the table. -1 ).

[0061] For example, the number of functional groups in -COF refers to the number of functional groups originating from the absorption frequency of -CF2COF, which is 1883 cm⁻¹. -1 The number of functional groups derived from the absorption peak at 1840 cm⁻¹ and the absorption frequency originating from -CH₂COF were also analyzed. -1 The total number of functional groups obtained from the absorption peak at the given location.

[0062] Functional groups are those present at the ends of the main chain or side chains of the copolymer, and those present in the main chain or side chains. The number of functional groups can be the total number of -CF=CF2, -CF2H, -COF, -COOH, -COOCH3, -CONH2, and -CH2OH.

[0063] The aforementioned functional groups are introduced into the copolymer, for example, through chain transfer agents or polymerization initiators used in the manufacturing of the copolymer. For instance, when an alcohol is used as a chain transfer agent, or when a peroxide having a -CH2OH structure is used as a polymerization initiator, -CH2OH is introduced to the ends of the copolymer's main chain. Alternatively, the aforementioned functional groups are introduced to the ends of the copolymer's side chains by polymerizing monomers containing functional groups.

[0064] By fluorinating the copolymer having such functional groups, copolymers with the number of functional groups within the aforementioned range can be obtained. That is, the copolymer contained in the injection-molded article of the present invention is preferably a fluorinated copolymer. The copolymer contained in the injection-molded article of the present invention further preferably has a -CF3 terminal group.

[0065] The melting point of the copolymer is preferably 295–315°C, more preferably 300°C or higher, even more preferably 301°C or higher, particularly preferably 302°C or higher, more preferably 310°C or lower, and even more preferably 305°C or lower. By having a melting point within the above range, wear on the inner surface of the tube body and a decrease in the sealing performance of the flange can be further suppressed.

[0066] In this invention, the melting point can be determined using a differential scanning calorimeter (DSC).

[0067] The storage modulus (E') of the injection-molded article of the present invention at 150°C is preferably 67 MPa or more, more preferably 70 MPa or more. By ensuring that the storage modulus (E') of the injection-molded article at 150°C is within the above-mentioned range, the elastic modulus of the injection-molded article at high temperatures becomes higher, and the high-temperature elasticity becomes more excellent. Therefore, the sealing performance of the flange portion can be further improved, and the reduction of sealing performance can be further suppressed.

[0068] Storage modulus (E') can be determined by dynamic viscoelasticity measurement in the range of 30℃ to 250℃ under conditions of heating rate of 2℃ / min and frequency of 10Hz.

[0069] The injection-molded article of the present invention can be manufactured by injection molding the above-mentioned copolymer. More specifically, the injection-molded article of the present invention can be manufactured by a manufacturing method in which the copolymer is injection molded using an injection molding machine equipped with a barrel and a screw housed within the barrel. The shape of the copolymer supplied to the injection molding machine is not particularly limited, and copolymers in the form of powder, granules, etc., can be used.

[0070] Alternatively, a core material can be placed in the hollow part of the tube or valve, and molten copolymer can be injected from the injection molding machine into the gap between the inner surface of the tube or valve and the core material. The copolymer can be cooled and solidified, and the core material can be pulled out, thereby creating an injection-molded body that is bushed on the inner surface of the tube or valve.

[0071] The injection-molded articles of the present invention are suitable for use as liner components for liner tubes or lined valves.

[0072] By using the injection-molded body of the present invention to line the inner surface of a tube, a liner can be manufactured. The liner may comprise a liner member formed by the injection-molded body of the present invention and a tube body lined by the liner member. By using the liner member to form the fluid-contacting surface of the liner, corrosion of the tube body can be suppressed even when the tube body is made of metal, and scale adhesion to the inner surface of the liner can be prevented. The liner is preferably used as piping for the flow of reagents.

[0073] By using the injection-molded body of the present invention to line the inner surface of the valve body, a lined valve can be manufactured. The lined valve may include a liner formed by the injection-molded body of the present invention and a valve body lined by the liner. By using the liner to form the fluid-contacting surface of the lined valve, corrosion of the valve body can be suppressed even when the valve body is made of metal, and scale adhesion to the inner surface of the lined valve can be suppressed. The lined valve is preferably used as a valve for allowing reagent flow.

[0074] The embodiments have been described above, but it is understood that various changes can be made to the methods and details without departing from the spirit and scope of the claims.

[0075] Example

[0076] Next, embodiments will be given to illustrate the implementation of the present invention, but the present invention is not limited to the embodiments described herein.

[0077] The values ​​in the examples were measured using the following methods.

[0078] (Monomer content)

[0079] The content of each monomer unit was determined by an NMR analyzer (e.g., an AVANCE300 high-temperature probe manufactured by Bruker BioSpin).

[0080] (Mel flow rate (MFR))

[0081] According to ASTM D1238, the mass (g / 10 min) of polymer flowing out of a nozzle with an inner diameter of 2.1 mm and a length of 8 mm per 10 minutes was determined using a melt indexer G-01 (manufactured by Toyo Seiki Co., Ltd.) at 372°C and a load of 5 kg.

[0082] (Melting point)

[0083] The first heating was performed using a differential scanning calorimeter (trade name: X-DSC7000, manufactured by Hitachi High-Tech Science) at a heating rate of 10°C / min, from 200°C to 350°C. Then, the temperature was cooled from 350°C to 200°C at a cooling rate of 10°C / min. The second heating was performed again at a heating rate of 10°C / min, from 200°C to 350°C. The melting point was determined from the peak value of the melting curve generated during the second heating process.

[0084] (Number of functional groups)

[0085] The copolymer granules were cold-pressed to produce films with a thickness of 0.25 mm to 0.3 mm. The films were then scanned 40 times using a Fourier transform infrared spectroscopy (FT-IR) device (Spectrum One, PerkinElmer) to obtain infrared absorption spectra. A differential spectrum was obtained between this spectrum and the background spectrum of the fully fluorinated film, which lacks functional groups. The concentration of the sample relative to each 1 × 10⁻⁶ functional group was calculated from the absorption peaks of specific functional groups observed in the differential spectrum according to the following formula (A). 6 The number of functional groups N per carbon atom.

[0086] N = I × K / t (A)

[0087] I: Absorbance

[0088] K: Correction coefficient

[0089] t: Membrane thickness (mm)

[0090] For reference, the absorption frequencies, molar absorptivity, and correction factors for the functional groups in this invention are shown in Table 2. The molar absorptivity was determined from FT-IR measurements of low-molecular-weight model compounds.

[0091] [Table 2]

[0092]

[0093] Synthesis example 1

[0094] 51.8 L of pure water was added to a 174 L autoclave, and after thorough nitrogen purging, 40.9 kg of perfluorocyclobutane, 0.54 kg of perfluoropropyl vinyl ether (PPVE), and 5.10 kg of methanol were added. The system temperature was maintained at 35 °C, and the stirring speed was maintained at 200 rpm. Next, tetrafluoroethylene (TFE) was injected to 0.64 MPa, followed by 0.051 kg of a 50% methanol solution of di-n-propyl peroxide dicarbonate, to initiate polymerization. As the pressure in the system decreased during polymerization, TFE was continuously supplied to maintain a constant pressure, with 0.020 kg of PPVE added for every 1 kg of TFE supplied. The polymerization was stopped when the amount of TFE added reached 40.9 kg. After releasing the unreacted TFE and restoring the autoclave to atmospheric pressure, the resulting reaction product was washed with water and dried to obtain 41.1 kg of powder.

[0095] The obtained powder was melt-extruded at 360°C using a screw extruder (trade name: PCM46, manufactured by Ikebe Co., Ltd.) to obtain TFE / PPVE copolymer granules. The PPVE content of the obtained granules was determined using the method described above.

[0096] The obtained granules were placed in a VVD-30 vacuum vibratory reactor (manufactured by Okawahara Seisakusho Co., Ltd.) and heated to 210°C. After evacuation, F2 gas diluted to 20% by volume with N2 gas was introduced to atmospheric pressure. 0.5 hours after the introduction of F2 gas, the reactor was temporarily evacuated, and F2 gas was introduced again. Then, after another 0.5 hours, the reactor was evacuated again, and F2 gas was introduced again. This process of introducing F2 gas and evacuating the reactor was repeated once every hour, and the reaction was carried out at 210°C for 10 hours. After the reaction was completed, the reactor was completely replaced with N2 gas to end the fluorination reaction. Various physical properties of the fluorinated granules were measured using the above method.

[0097] Synthesis example 2

[0098] The amount of PPVE was changed to 3.47 kg, the amount of methanol was changed to 3.28 kg, the amount of 50% methanol solution of di-n-propyl peroxide was changed to 0.026 kg, and the amount of PPVE was changed to 0.071 kg added for every 1 kg of TFE supplied, resulting in 43.8 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Synthesis Example 1.

[0099] Synthesis example 3

[0100] The amount of PPVE was changed to 2.69 kg, methanol to 0.10 kg, and the 50% methanol solution of di-n-propyl peroxide was changed to 0.026 kg. The amount of PPVE was changed to 0.057 kg added for every 1 kg of TFE supplied, resulting in 43.2 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Synthesis Example 1.

[0101] Synthesis example 4

[0102] The amount of PPVE was changed to 2.69 kg, the amount of methanol was changed to 2.48 kg, and the amount of PPVE was changed to an additional 0.057 kg for every 1 kg of TFE supplied, resulting in 43.2 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Synthesis Example 1.

[0103] Synthesis example 5

[0104] The amount of PPVE was changed to 2.75 kg, the amount of methanol was changed to 0.88 kg, and the amount of PPVE was changed to 0.058 kg added for every 1 kg of TFE supplied, resulting in 43.3 kg of dry powder. Otherwise, unfluorinated granules were obtained in the same manner as in Synthesis Example 1.

[0105] Synthesis example 6

[0106] The amount of PPVE was changed to 1.49 kg, the amount of methanol was changed to 1.65 kg, and the amount of PPVE was changed to 0.036 kg added for every 1 kg of TFE supplied, resulting in 42.4 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Synthesis Example 1.

[0107] Synthesis Example 7

[0108] The amount of PPVE was changed to 2.11 kg, the amount of methanol was changed to 1.28 kg, the amount of PPVE was changed to 0.047 kg added for every 1 kg of TFE supplied, the heating temperature of the vacuum vibrating reactor was changed to 170°C, and the reaction time at 170°C was changed to 5 hours, resulting in 42.8 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Synthesis Example 1.

[0109] Synthesis example 8

[0110] The amount of PPVE was changed to 2.75 kg, the amount of methanol was changed to 0.60 kg, and the amount of PPVE was changed to 0.058 kg added for every 1 kg of TFE supplied, resulting in 43.3 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Synthesis Example 1.

[0111] The results are shown in Table 3.

[0112] [Table 3]

[0113] Table 3

[0114]

[0115] The “<6” in Table 3 refers to the number of functional groups being less than 6.

[0116] Examples 1 to 8

[0117] Using the granules obtained above, injection molded parts were fabricated using the following method. The results are shown in Table 4.

[0118] Fabrication of injection-molded parts (1) (Comparative)

[0119] Using an injection molding machine (Sumitomo Heavy Industries, SE50EV-A), the barrel temperature was set to 395°C, the mold temperature to 220°C, the injection speed to 3 mm / s, and the holding pressure to 50 MPa. The granules were injected to produce a sheet-like injection molded body (10 cm × 10 cm × 0.10 cmt). By cutting the obtained sheet-like injection molded body, it was possible to produce an injection molded body (1), but the molten copolymer could not be fully filled into the mold, and the molded body could not be obtained.

[0120] Fabrication of injection molded part (2)

[0121] Using an injection molding machine (Sumitomo Heavy Industries, SE50EV-A), the barrel temperature was set to 395°C, the mold temperature to 220°C, the injection speed to 3 mm / s, and the holding pressure to 50 MPa. The granules were injected to form a sheet-like injection molded body (10 cm × 10 cm × 0.30 cmt). The resulting sheet-like injection molded body was then cut to form an injection molded body (2).

[0122] Fabrication of injection molded body (3)

[0123] Using an injection molding machine (Sumitomo Heavy Industries, SE50EV-A), the barrel temperature was set to 395°C, the mold temperature to 220°C, the injection speed to 3 mm / s, and the holding pressure to 50 MPa. The granules were injected to form a sheet-like injection molded body (5 cm × 5 cm × 0.7 cmt). The resulting sheet-like injection molded body was then cut to form an injection molded body (3).

[0124] Fabrication of injection molded part (4)

[0125] Using an injection molding machine (Sumitomo Heavy Industries, SE50EV-A), the barrel temperature was set to 395°C, the mold temperature to 220°C, the injection speed to 3 mm / s, and the holding pressure to 50 MPa. The granules were injected to form a sheet-like injection molded body (5 cm × 5 cm × 1.0 cmt). The resulting sheet-like injection molded body was then cut to form an injection molded body (4).

[0126] Fabrication of injection-molded parts (5) (Comparative)

[0127] Using an injection molding machine (Sumitomo Heavy Industries, SE50EV-A), the barrel temperature was set to 395°C, the mold temperature to 220°C, the injection speed to 3 mm / s, and the holding pressure to 50 MPa. The granules were injected to form a sheet-like injection molded body (5 cm × 5 cm × 1.5 cmt). The resulting sheet-like injection molded body was then cut to form an injection molded body (5).

[0128] For injection molded parts (2) to (5), the appearance was evaluated according to the following criteria. The results are shown in Table 5. In Table 5, “unformable” means that the molten copolymer could not be fully filled into the mold and a molded part could not be obtained.

[0129] (Formability evaluation (porosity))

[0130] Visually inspect 10 injection molded parts and evaluate them according to the following criteria.

[0131] N: There are no gaps in the entire molded body.

[0132] Y: Voids were observed in more than one molded body.

[0133] (Formability evaluation (burrs))

[0134] Visually inspect the injection-molded parts and evaluate them according to the following criteria.

[0135] N: No rough edges

[0136] Y: Observed rough edges

[0137] [Table 4]

[0138] Table 4

[0139]

[0140] Examples 9-13 (comparison), Examples 14-16

[0141] The injection-molded articles obtained above were evaluated using the following methods. The results are shown in Table 5.

[0142] (Abrasion test)

[0143] Using the injection-molded body (2) obtained above as a test piece, the test piece was fixed on the test bench of a Taber abrasion testing machine (No. 101 Special Type Taber Abrasion Testing Machine, manufactured by Yasuda Seiki Co., Ltd.). An abrasion test was conducted using the Taber abrasion testing machine under the following conditions: test piece surface temperature 90°C, load 500g, abrasion wheel CS-10 (grinding with #240 abrasive paper for 20 revolutions), and rotation speed 60 rpm. The weight of the test piece was measured after 1000 revolutions, and the same test piece was further tested after 5000 revolutions, and the weight of the test piece was measured again. The abrasion amount was calculated using the following formula.

[0144] Wear amount (mg) = M1 - M2

[0145] M1: Weight of the test piece after 1000 revolutions (mg)

[0146] M2: Weight of the test piece (mg) after 5000 revolutions.

[0147] (Creep Resistance Evaluation)

[0148] Creep resistance was determined according to the methods described in ASTM D395 or JIS K6262:2013. Test pieces with an outer diameter of 13 mm and a height of 6 mm were prepared by cutting the injection-molded body (3) obtained above. The test pieces were compressed to a compression set of 25% at room temperature using a compression device. The compressed test pieces were then placed in an electric furnace at 80°C for 72 hours while still fixed in the compression device. The compression device was removed from the furnace, and after cooling to room temperature, the test pieces were removed. The height of the recovered test pieces was measured after being placed at room temperature for 30 minutes, and the recovery ratio was calculated using the following formula. The molded body, which fully recovered its shape even after compression at 80°C, exhibited excellent creep resistance, and its sealing performance was not easily reduced even when used at high temperatures.

[0149] Recovery rate (%) = (t2-t1) / t3 × 100

[0150] t1: Height of the spacer (mm)

[0151] t2: Height of the test piece removed from the compression device (mm)

[0152] t3: Height of compression deformation (mm)

[0153] In the above experiment, t1 = 4.5 mm and t3 = 1.5 mm.

[0154] (Storage Modulus (E'))

[0155] The dynamic viscoelasticity was determined using a DVA-220 (manufactured by IT Measurement & Control Co., Ltd.). The injection-molded body (3) obtained above was cut out, and test pieces with a length of 25 mm, a width of 2 mm, and a thickness of 1 mm were prepared. Using the prepared test pieces, measurements were taken in the range of 30℃ to 250℃ at a heating rate of 2℃ / min and a frequency of 10Hz, and the storage modulus (MPa) at 150℃ was read. Molded bodies with a high storage modulus at 150℃ exhibit moderate hardness even at high temperatures, and their sealing performance is not easily reduced even when used at high temperatures.

[0156] (Recovery Amount)

[0157] The recovery amount was determined according to the methods described in ASTM D395 or JIS K6262:2013.

[0158] By cutting the injection-molded body (3) obtained above, a test piece with an outer diameter of 13 mm and a height of 6 mm was made. Using a compression device, the test piece was compressed at room temperature to a compression deformation rate of 50% (i.e., the test piece with a height of 6 mm was compressed to a height of 3 mm). The compressed test piece was placed in an electric furnace with the compression device fixed in place and placed at 150°C for 18 hours. The compression device was removed from the electric furnace, cooled to room temperature, and the test piece was removed. After the recovered test piece was placed at room temperature for 30 minutes, the height of the recovered test piece was measured, and the recovery amount was calculated using the following formula.

[0159] Recovery amount (mm) = t2 - t1

[0160] t1: Height of the spacer (mm)

[0161] t2: Height of the test piece removed from the compression device (mm)

[0162] In the above experiment, t1 = 3 mm.

[0163] (Rebound force at 150℃)

[0164] Based on the results of the compression set test at 150℃ and the storage modulus measurement at 150℃, the rebound force at 150℃ is calculated using the following formula.

[0165] Resilience force at 150℃ (MPa) = (t2-t1) / t1×E'

[0166] t1: Height of the spacer (mm)

[0167] t2: Height of the test piece removed from the compression device (mm)

[0168] E': Energy storage modulus at 150℃ (MPa)

[0169] Even at high temperatures, molded parts with high resilience at 150°C maintain high sealing performance, and their sealing performance is not easily reduced even when used continuously at high temperatures.

[0170] [Table 5]

[0171] Table 5

[0172]

[0173] As shown in Table 4, by adjusting the flange thickness (i.e., the thickness of the mold cavity) to an appropriate range and using copolymers with FAVE unit content, MFR, and functional group number within extremely limited ranges for injection molding, flanges without molding defects can be formed. Conversely, if the flange thickness is too small, the thickness of the mold cavity used in injection molding also becomes small, making it difficult to fill the mold with the copolymer and resulting in an injection-molded body with the desired flange shape. It is also evident that if the flange thickness is too large, the thickness of the mold cavity used for injection molding also becomes large, thus producing molding defects known as voids. Voids reduce the mechanical strength of the flange and are therefore undesirable.

[0174] As shown in Table 5, the injection-molded body formed from copolymers with FAVE unit content, MFR, and functional group number within extremely limited ranges exhibits low wear at 90°C, excellent creep resistance, high storage modulus, and high resilience at 150°C. Therefore, the injection-molded body of the present invention, formed from copolymers with FAVE unit content, MFR, and functional group number within extremely limited ranges, can effectively suppress wear on the inner surface of the tube portion caused by high-temperature fluid flow. Furthermore, by tightening the flange portion, even when the injection-molded body of the present invention is connected to other components, the connection is adequately sealed despite the large flange thickness, and the excellent sealing performance is not easily compromised even during continued use at high temperatures.

Claims

1. An injection-molded article comprising: a tubular portion forming a flow path for a fluid; and flange portions formed at one or both ends of the tubular portion, wherein, The maximum thickness of the flange portion is 2mm to 12mm. The injection-molded article contains a copolymer, which contains tetrafluoroethylene units and fluorinated (alkyl vinyl ether) units. The copolymer contains fluorinated (alkyl vinyl ether) units at a rate of 2.8% to 6.0% by mass relative to all monomer units. The copolymer has a melt flow rate of 4.0 g / 10 min or more and less than 11.0 g / 10 min at 372°C. per 10 6 total number of functional groups of -CF=CF2, -CF2H, -COF, -COOH, -COOCH3, -CONH2, and -CH2OH of the copolymer is 50 or less.

2. The injection-molded article as described in claim 1, wherein, The fluorinated (alkyl vinyl ether) unit of the copolymer is a perfluoro (propyl vinyl ether) unit.

3. The injection-molded article as described in claim 1 or 2, wherein, The content of the fluorinated (alkyl vinyl ether) unit in the copolymer is 3.5% to 5.5% by mass relative to all monomer units.

4. The injection-molded article as described in claim 1 or 2, wherein, The copolymer has a melt flow rate of 5.0 g / 10 min to 9.0 g / 10 min at 372 °C.

5. The injection-molded article as described in claim 1 or 2, wherein, The copolymer has a melting point of 295°C to 315°C.

6. The injection-molded article as described in claim 1 or 2, wherein it is a liner component for a liner tube or a liner valve.

7. A liner, wherein the fluid contact surface is lined by an injection-molded body according to any one of claims 1 to 6.

8. A lined valve, wherein the fluid contact surface is lined by an injection-molded body according to any one of claims 1 to 6.

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