TW202033574A - Fluoropolymer composition, molded article, and injection molded article - Google Patents

Abstract

Provided is a fluoropolymer composition containing an electroconductive carbon compound and a copolymer that contains a tetrafluoroethylene unit and a fluoroalkyl vinyl ether unit, wherein the fluoroalkyl vinyl ether unit content is 5.0-8.0 mass% relative to the total monomer units constituting the copolymer, the volume resistivity of the fluoropolymer composition is 104-109 [Omega]·cm, and the melt flow rate of the fluoropolymer composition is 1-100 g/10 min.

Description

Fluoropolymer composition, molded product, and injection molded product

The present invention relates to a fluoropolymer composition, molded product, and injection molded product.

The semiconductor manufacturing process usually includes the step of treating wafers with chemical liquids. As an apparatus used in such a processing step, for example, Patent Document 1 describes a semiconductor cleaning apparatus that includes a wafer rotating base such as a rotating table that fixes the wafer to be cleaned on the upper surface and can rotate. The wafer rotating base is arranged in a wafer cup formed by a concave container. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2012-54269 A

[The problem to be solved by the invention]

The object of the present invention is to provide a fluoropolymer composition that can obtain large-sized and hard-to-charge fluoropolymer molded products such as wafer cups. [Technical means to solve the problem]

According to the present invention, there is provided a fluoropolymer composition comprising: a copolymer containing tetrafluoroethylene units and fluoroalkyl vinyl ether units, and a conductive carbon compound, with respect to all monomer units constituting the copolymer, the above The content of the fluoroalkyl vinyl ether unit is 5.0 to 8.0% by mass, the volume resistivity of the fluoropolymer composition is 10 ^{4 to} 10 ⁹ Ω·cm, and the melt flow rate of the fluoropolymer composition is 1 to 100 g/10 minutes.

The above-mentioned copolymer is preferably at least one selected from the group consisting of the following copolymers: a copolymer composed only of tetrafluoroethylene units and fluoroalkyl vinyl ether units, and 0.1~10% by mass from which can be combined with The monomer unit of the monomer copolymerized with tetrafluoroethylene and fluoroalkyl vinyl ether is a copolymer of 90 to 99.9% by mass of tetrafluoroethylene units and fluoroalkyl vinyl ether units. The conductive carbon compound is preferably at least one selected from the group consisting of conductive carbon black and carbon nanotubes. The content of the conductive carbon compound is preferably 0.02-15% by mass relative to the fluoropolymer composition.

Furthermore, according to the present invention, there is provided a molded product obtained by molding the above-mentioned fluoropolymer composition.

Furthermore, according to the present invention, there is provided an injection molded product obtained by injection molding the above-mentioned fluoropolymer composition. [Effects of Invention]

According to the present invention, it is possible to provide a fluoropolymer composition that can obtain a large fluoropolymer molded product that is difficult to charge.

Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

As shown in Patent Document 1, the wafer cup is arranged to surround the wafer rotating base, and contains water or chemical liquid scattered from the wafer rotating base. Such wafer cups are generally large and require excellent chemical resistance, so they are manufactured by cutting polytetrafluoroethylene blocks.

However, cutting polytetrafluoroethylene blocks requires a longer time burden and a greater economic burden, so new materials and manufacturing methods are required. As a method of manufacturing fluoropolymer molded products, there is also known a method of melt-molding a melt-processable fluoropolymer, but large molded products obtained by molding a melt-processable fluoropolymer are prone to cracks. And the problem is not easy to form.

Furthermore, it has been learned that if scattered water or chemical liquid adheres to a large molded product obtained by molding a fluoropolymer, and the water or chemical liquid becomes droplets and flows on the surface of the molded product, the molded product will It is charged due to frictional charging or peeling charging with the droplets. Once the fluoropolymer molded product is charged, it is not easy to discharge. Therefore, there may be a problem that the droplets scattered on the molded product such as the wafer cup return to the wafer in a static state due to electrostatic repulsion, causing the semiconductor device to malfunction, etc., and it is presumed that the cause is the charging of the molded product. Therefore, countermeasures against static electricity in production lines in the semiconductor manufacturing process are an important issue that affects the "yield rate" of the production of semiconductor devices.

The fluoropolymer composition of the present invention contains a fluoropolymer and a conductive carbon compound. The fluoropolymer contains tetrafluoroethylene units and fluoroalkyl vinyl ether units in a strictly limited ratio, and the volume resistivity and melt flow rate are controlled by Adjust within a strictly restricted range. Since the fluoropolymer composition of the present invention has these constitutions, it has excellent moldability, and can provide large molded products with excellent crack resistance and difficult to be charged without a long time burden and a large economic burden. .

The fluoropolymer composition of the present invention contains a copolymer (hereinafter referred to as PFA) which contains a tetrafluoroethylene unit (TFE unit) and a fluoroalkyl vinyl ether unit (FAVE unit).

The above-mentioned PFA is preferably a fluororesin having melt processability. In the present invention, the term "melt processability" means that the polymer can be melted and processed using conventional processing machines such as extruders and injection molding machines. Therefore, the melt flow rate of a fluororesin with melt processability measured by the following measuring method is usually 0.01 to 500 g/10 minutes.

The content of the FAVE unit in the above-mentioned PFA is 5.0 to 8.0% by mass relative to all monomer units. From the viewpoint of obtaining a large molded product with more excellent crack resistance, it is preferably 5.5% by mass or more, more preferably 7.5 Mass% or less, more preferably 7.0 mass% or less. The content of the above FAVE unit can be measured by ¹⁹ F-NMR method.

As the FAVE constituting the FAVE unit, at least one selected from the group consisting of the monomer represented by the general formula (1) and the monomer represented by the general formula (2): CF ₂ =CFO(CF _{2 ^{CFY 1 O) p - (CF}} 2 CF 2 CF 2 O) q -Rf 1 (1) ( wherein, Y ¹ represents F or CF _3, Rf ¹ represents a perfluoroalkyl group having a carbon number of 1 ~ 5; p Represents an integer from 0 to 5, q represents an integer from 0 to 5); CFX=CXOCF ₂ OR ¹ (2) (where X is the same or different, represents H, F or CF ₃ , and R ¹ represents straight or branched chain The fluoroalkyl group with a carbon number of 1 to 6 or a cyclic fluoroalkyl group with a carbon number of 5 or 6. The above-mentioned fluoroalkyl group may contain 1 to 2 selected from the group consisting of H, Cl, Br and I At least one atom, the above-mentioned cyclic fluoroalkyl group may contain 1 to 2 at least one atom selected from the group consisting of H, Cl, Br and I).

Among them, the above-mentioned FAVE is preferably a monomer represented by the general formula (1), more preferably perfluoro (alkyl vinyl ether), and more preferably selected from perfluoro (methyl vinyl ether) and perfluoro At least one of the group consisting of (ethyl vinyl ether) and perfluoro (propyl vinyl ether) (PPVE), particularly preferably PPVE.

In the above-mentioned PFA, the mass ratio of TFE unit to FAVE unit (TFE unit/FAVE unit) is preferably 95.0/5.0~92.0/8.0, more preferably 95.0/5.0~92.5/7.5, and still more preferably 94.5/5.5 ~93.0/7.0. If there are too many TFE units, there is a tendency for mechanical properties such as crack resistance to decrease, and if there are too few TFE units, there is a tendency for the melting point to decrease and heat resistance to decrease.

The above-mentioned PFA is also preferably a copolymer composed of only TFE units and FAVE units, or 0.1-10% by mass of monomer units derived from monomers copolymerizable with TFE and FAVE and a total of 90-99.9% by mass of TFE Unit and FAVE unit copolymer.

As monomers copolymerizable with TFE and FAVE, hexafluoropropylene (HFP), CZ ¹ Z ² =CZ ³ (CF ₂ ) _n Z ⁴ (wherein Z ¹ , Z ² and Z ^{3 are the} same or Different, it means H or F, Z ⁴ means H, F or Cl, n means an integer from 2 to 10), and CF ₂ =CF-OCH ₂ -Rf ² (where Rf ² means carbon Perfluoroalkyl groups (numbers 1 to 5) represent alkyl perfluorovinyl ether derivatives, etc. Among them, HFP is preferred.

The above-mentioned PFA is preferably at least one selected from the group consisting of the following copolymers: copolymers composed only of TFE units and FAVE units, and TFE/HFP/FAVE containing TFE units, HFP units, and FAVE units The copolymer is more preferably a copolymer composed only of TFE units and FAVE units.

The melting point of the above-mentioned PFA is preferably 280 to 322°C, more preferably 290°C or higher, and more preferably 315°C or lower. The above melting point can be measured using a differential scanning calorimeter [DSC].

The glass transition temperature (Tg) of the above-mentioned PFA is preferably 70 to 110°C, more preferably 80°C or higher, and more preferably 100°C or lower. The above-mentioned glass transition temperature can be measured by dynamic viscoelasticity measurement.

The above-mentioned PFA may be one having terminal groups such as -CF ₃ and -CF ₂ H in at least one of the polymer main chain and the polymer side chain, and is not particularly limited, but is preferably fluorinated PFA. PFA that has not been fluorinated has terminal groups that contain -COOH, -COOCH ₃ , -CH ₂ OH, -COF, -CONH ₂ and other unstable thermal and electrical characteristics (hereinafter, such terminal groups are also referred to as " Unstable end group"). Such unstable terminal groups can be reduced by the above-mentioned fluorination treatment.

The PFA preferably contains less or no such unstable terminal groups, and the total number of unstable terminal groups is preferably 120 or less per 1×10 ⁶ carbons.

Regarding the above-mentioned PFA, considering that it can suppress molding defects caused by foaming during molding, the total number of the above-mentioned five kinds of unstable end groups and -CF ₂ H end groups, namely -COOH, -COOCH ₃ , -CH The total number of ₂ OH, -COF, -CONH ₂ , and -CF ₂ H is more preferably 120 or less per 1×10 ⁶ carbon number. If there are more than 120, there is a risk of forming defects. The above-mentioned unstable terminal groups are more preferably 50 or less, still more preferably 20 or less, and most preferably 10 or less. In the present invention, the aforementioned unstable terminal base is a value obtained by infrared absorption spectrometry. The above-mentioned unstable terminal group and the -CF ₂ H terminal group may not be present and both are -CF ₃ terminal groups. Infrared spectroscopy can be used to identify the types of functional groups and determine the number of functional groups.

The above-mentioned fluorination treatment can be performed by contacting PFA that has not been fluorinated with a fluorine-containing compound.

The fluorine-containing compound is not particularly limited, and a fluorine radical source that generates fluorine radicals under fluorination treatment conditions can be mentioned. Examples of the fluorine radical source include F ₂ gas, CoF ₃ , AgF ₂ , UF ₆ , OF ₂ , N ₂ F ₂ , CF ₃ OF, halogen fluoride (for example, IF ₅ , ClF ₃ ), and the like.

F ₂ gas or the like above the source of fluorine radicals may be 100% by concentration, but in view of safety, is preferably mixed with the inert gas, used after diluted to 5~50 mass%, more preferably diluted to 15~30 Use after mass%. As said inert gas, nitrogen, helium, argon, etc. can be mentioned, but nitrogen is preferable from an economic point of view.

The conditions of the fluorination treatment are not particularly limited. The molten PFA can be brought into contact with the fluorine-containing compound. Generally, it can be below the melting point of the PFA, preferably 20 to 220°C, more preferably 100 to 200°C Under. The above-mentioned fluorination treatment is generally performed for 1 to 30 hours, preferably for 5 to 25 hours. The fluorination treatment preferably involves contacting the unfluorinated PFA with fluorine gas (F ₂ gas).

The above-mentioned PFA can be produced by bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, or the like.

The fluoropolymer composition of the present invention contains a conductive carbon compound. By using a conductive carbon compound as a conductive filler, a molded product that is difficult to elute the conductive filler even when in contact with an acidic chemical solution can be obtained. Examples of conductive carbon compounds include conductive carbon black, graphite, carbon fiber, expanded graphite, graphene, carbon nanotubes, carbon nanohorns, etc. Among them, it is considered that large molded products that are more difficult to charge can be obtained , Preferably at least one selected from the group consisting of conductive carbon black and carbon nanotubes. In addition, as a conductive carbon compound, from the viewpoint of imparting excellent antistatic properties to molded products even when added in a small amount, carbon nanotubes are more preferable, and from the viewpoint of cost advantages, conductive carbon black is more preferable .

As the conductive carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, etc. can be cited. Among them, it is preferably selected from the group consisting of acetylene black and Ketjen black. At least one of them, more preferably Ketjen Black.

Carbon nanotubes are formed by rolling graphene sheets composed of condensed benzene rings into a cylindrical shape. Examples include single-layer carbon nanotubes (SWCNT), multilayer carbon nanotubes (MWCNT), and vapor-grown carbon fibers ( VGCF) and so on. Carbon nanotubes can be fibrous materials with a diameter (fiber diameter) of 2 to 250 nm and a length of 1 to 200 μm. Because of the high aspect ratio of carbon nanotubes, it is easy to form a network in the matrix resin. Also, because it is relatively fine, the number of roots per unit weight is large. Therefore, there is a possibility that a small amount of addition can give the composition sufficient conductivity.

The fluoropolymer composition of the present invention may contain other components as necessary. Other components include fillers, crosslinking agents, heat-resistant stabilizers, foaming agents, foaming nucleating agents, antioxidants, surfactants, photopolymerization initiators, anti-wear agents, surface modifiers, and other additives. .

The volume resistivity of the fluoropolymer composition of the present invention is 10 ^{4 to} 10 ⁹ Ω·cm. From the viewpoint of obtaining large molded products that are more difficult to charge, it is preferably 10 ⁶ Ω·cm or more, and more preferably 10 ⁸ Ω·cm or less.

The volume resistivity of the fluoropolymer composition of the present invention is the volume resistivity of a molded product obtained by molding the fluoropolymer composition of the present invention. The volume resistivity of the fluoropolymer composition of the present invention is in accordance with ASTM D 991 when measuring low-resistance areas and ASTM D 257 when measuring high-resistance areas. It can be used at a room temperature of 23°C and a humidity of 50%. Accuracy resistivity meter or multi-purpose high resistivity meter for measurement.

The volume resistivity of the fluoropolymer composition of the present invention can be adjusted by adjusting the type and content of the conductive carbon compound. That is, in the fluoropolymer composition of the present invention, the type and content of the conductive carbon compound are preferably adjusted so that the volume resistivity of the fluoropolymer composition falls within the aforementioned range.

Mainly according to the shape of the conductive carbon compound, the relationship between the content in the composition and the volume resistivity of the composition will be different, so the optimal content in the composition can be selected according to the shape of the conductive carbon compound. The shape of the conductive carbon compound may be granular, fibrous, scaly, flake, etc., and is preferably granular or fibrous. For example, carbon nanotubes have a slender fiber-like shape to form an electric path, so there is a tendency to obtain an appropriate volume resistivity even when the content is small. On the other hand, when conductive carbon black is used as the conductive carbon compound, there is a tendency that more than the content of carbon nanotubes is required. In addition, when the conductive carbon compound uses a smaller primary particle, the primary particles gather to become a slightly larger mass, and the mass becomes agglomerated mass, which tends to increase in size. Therefore, comparing two kinds of conductive carbon compounds with different primary particle sizes, it is found that even if the content in the composition is the same, the dispersibility of the conductive carbon compound in the composition is different, and the volume resistivity of the composition is different. Sex.

The fluoropolymer composition of the present invention has a melt flow rate (MFR) of 1-100 g/10 minutes, and is more excellent in self-formability, and in terms of obtaining large-scale molded products with more excellent crack resistance, it is more preferable 10 g/10 minutes or more, more preferably 20 g/10 minutes or more, particularly preferably 25 g/10 minutes or more, more preferably 90 g/10 minutes or less, and still more preferably 70 g/10 minutes or less, Particularly preferred is less than 60 g/10 minutes. The MFR of the fluoropolymer composition is based on ASTM D1238, using a melt index tester (manufactured by Yasuda Seiki Co., Ltd.) at 372°C and a load of 5 kg. From a nozzle with an inner diameter of 2 mm and a length of 8 mm every 10 minutes The value of the mass of polymer flowing out (g/10 minutes).

The MFR of the fluoropolymer composition of the present invention can be adjusted by adjusting the type and content of the conductive carbon compound, and the MFR of PFA. That is, in the fluoropolymer composition of the present invention, the type and content of the conductive carbon compound and the MFR of PFA are preferably adjusted so that the MFR of the fluoropolymer composition falls within the aforementioned range. In addition, when the fluoropolymer composition is prepared by the melt-kneading method, the MFR of the fluoropolymer composition can also be adjusted by adjusting the melt-kneading conditions such as the kneading temperature and the shear force.

As mentioned above, the content of the conductive carbon compound affects the volume resistivity of the fluoropolymer composition, and also affects the formability of the fluoropolymer composition and the crack resistance of the resulting molded product. For example, if the content of the conductive carbon compound increases, the fluidity of the fluoropolymer composition decreases and the moldability tends to deteriorate. In the case of using conductive carbon black as the conductive carbon compound, in order to obtain the required volume resistivity, a relatively large amount of conductive carbon black is required. Therefore, it is better to choose PFA with a larger MFR. However, if PFA with a larger MFR is selected, the mechanical strength of the resulting molded product is likely to decrease, especially when the molded product is large, cracks are likely to occur. In this way, it is not easy to simultaneously improve the moldability of the fluoropolymer composition and the crack resistance and antistatic properties of the molded article obtained from the fluoropolymer composition. However, since the fluoropolymer composition of the present invention has the above-mentioned structure, it has excellent moldability and can provide a large-sized molded product that is excellent in crack resistance and is difficult to charge.

Therefore, in the present invention, it is preferable to select the type and content of conductive carbon black and the MFR of PFA in consideration of the moldability of the fluoropolymer composition and the crack resistance and antistatic properties of the resulting molded article.

In the fluoropolymer composition of the present invention, the content of the conductive carbon compound is preferable to the fluoropolymer composition in terms of obtaining more excellent moldability and obtaining large molded products that are more difficult to charge. It is 0.02-15 mass%, more preferably 10 mass% or less, still more preferably 9.0 mass% or less, and more preferably 0.03 mass% or more.

In the fluoropolymer composition of the present invention, the content of the conductive carbon black is better than the fluoropolymer composition in terms of obtaining more excellent moldability and obtaining large molded products that are more difficult to charge. It is 0.02-15 mass%, more preferably 5.5 mass% or more, still more preferably 6.0 mass% or more, particularly preferably 7.0 mass% or more, more preferably 10 mass% or less, and still more preferably 9.0 mass% or less.

In the fluoropolymer composition of the present invention, as the content of carbon nanotubes, it is better than the fluoropolymer composition in terms of obtaining more excellent formability and obtaining large-scale molded products that are more difficult to charge. It is 0.02 to 15% by mass, more preferably 0.03% by mass or more, more preferably 10.0% by mass or less, still more preferably 7.0% by mass or less, particularly preferably 5.0% by mass or less.

As the melt flow rate (MFR) of the PFA present in the fluoropolymer composition of the present invention, it is preferable in terms of obtaining more excellent formability and obtaining large-scale molded products with more excellent crack resistance 1.0~100 g/10 minutes, more preferably 6.0 g/10 minutes or more, still more preferably 10 g/10 minutes or more, more preferably 90 g/10 minutes or less, and still more preferably 80 g/10 minutes or less , Particularly preferably less than 70 g/10 minutes. The MFR of PFA is based on ASTM D 1238, using a melt index tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) at 372°C and a load of 5 kg. It flows out from a nozzle with an inner diameter of 2 mm and a length of 8 mm every 10 minutes. The value of the polymer mass (g/10 minutes).

The MFR of PFA can be adjusted by adjusting the type and amount of the chain transfer agent added during the polymerization of the monomers constituting the PFA, and the type and amount of the polymerization initiator. In addition, when the PFA obtained by polymerization is pelletized by extrusion molding, it can also be adjusted by adjusting the extrusion temperature or adjusting the shear force added to the PFA. Furthermore, the MFR of PFA will also change during the preparation steps of the fluoropolymer composition described below. Therefore, the MFR of PFA existing in the fluoropolymer composition differs from the PFA used as the raw material for the preparation of the fluoropolymer composition. MFR is not necessarily the same.

The preparation method of the fluoropolymer composition of the present invention is not particularly limited, and examples thereof include a method of preparation by a solvent dispersion method, a method of preparation by a melt-kneading method, and the like. The solvent dispersion method may include, for example, a step of obtaining a mixed solution by mixing a powder or dispersion of PFA with a dispersion of a conductive carbon compound dispersed in a solvent; and a step of removing the solvent from the obtained mixed solution . Examples of the solvent for dispersing the conductive carbon compound in the solvent include water, alcohols, ester solvents, ketone solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, and chlorinated hydrocarbon solvents. When dispersing the conductive carbon compound in a solvent, dispersing agents such as acrylic dispersants, polyvinylpyrrolidone, and polyaniline sulfonic acid may also be used. The solvent can be removed from the obtained mixed liquid by a known method such as heating and drying. In addition, in order to efficiently remove the solvent or dispersant from the mixed liquid, the mixed liquid can also be supplied to subcritical carbon dioxide or supercritical carbon dioxide, and the solvent or dispersion liquid is dissolved in carbon dioxide, and then fluorine containing PFA and conductive carbon compounds is recovered Polymer composition.

As the melt-kneading method, for example, a method of melt-kneading PFA powder and a conductive carbon compound at a temperature higher than the melting point of PFA. An extruder can be used for melt kneading. In this case, a quantitative feeder can also be installed in the extruder, and the conductive carbon compound can be supplied to the extruder from the quantitative feeder, and the conductive carbon compound and PFA can be melted and kneaded . Although there is a tendency that the higher the shear force applied to PFA in the extruder, the more fully the PFA and the conductive carbon compound are mixed, but the high shear force causes part of the main chain of PFA to be cut, resulting in the MFR of PFA The situation of getting higher. In this case, based on the premise that the MFR is increased, the MFR of the PFA fed into the extruder can be selected. In addition, PFA and conductive carbon compounds can be kneaded together, or a PFA masterbatch containing a high concentration of conductive carbon compounds can be prepared in advance, and the resulting masterbatch can be melted and kneaded with PFA.

The shape of the fluoropolymer composition of the present invention is not particularly limited, and may be powder, slurry, dispersion, granules, and the like.

By molding the fluoropolymer composition of the present invention, a molded product can be obtained. Even when the molded product of the present invention is a large-sized molded product, it has excellent crack resistance and is difficult to charge.

The size of the molded product in the present invention is not particularly limited, and it may be a large molded product. The molded product of the present invention may have a larger projected area than "a wafer (semiconductor wafer) having a diameter of at least 300 mm or at least 450 mm", for example. The projected area of the molded article of the present invention is preferably 1000 cm ² or more, more preferably 1100 cm ² or more, and may be 5000 cm ² or less. The shape of the molded product having a projected area within the above range is not particularly limited. It can be cylindrical, bowl, box, cage, etc., as long as the largest projected area of the molded product seen from any direction is The above range is sufficient. Moreover, when the molded product is an injection molded product, it is preferable that the projected area of the injection direction is within the above-mentioned range. The so-called projected area of the injection direction refers to the visible area of the injection molded product when viewed from the nozzle direction of the injection molding machine, that is, the projected area of the nozzle direction. In addition, it is more preferable that the injection molded product having a projected area in the injection direction within the above-mentioned range has an injection area diffusion ratio of 3000 or more. The so-called shot area ratio refers to the shot area diffusion ratio in the direction orthogonal to the shot direction, that is, the ratio of the opening area of the nozzle tip to the projected area of the injection molded product.

The method of molding the fluoropolymer composition of the present invention is not particularly limited, and known methods such as extrusion molding, injection molding, transfer molding, inflation molding, and compression molding can be cited. These molding methods may be appropriately selected according to the shape of the obtained molded product. Among these molding methods, injection molding is preferred because of the ease of manufacturing large-scale molded products.

The injection molded product obtained by injection molding the fluoropolymer composition of the present invention is not particularly limited. By using the fluoropolymer composition of the present invention, it is possible to obtain a relatively large size, which is hard to crack and prevent A molded product with excellent electrostatic properties, so a large injection molded product is preferred.

As the injection molded product of the present invention, for example, an injection molded product having a cylindrical portion capable of accommodating a "wafer (semiconductor wafer) having a diameter of at least 300 mm or at least 450 mm" can be cited. The cylindrical part of the injection molded product is also preferably a part that can accommodate holding means such as a turntable, a rotating base, and a rotating chuck. The holding means is used to hold a wafer having a diameter within the above range. In a semiconductor cleaning device that cleans wafers with water or a chemical solution, a semiconductor manufacturing device that coats a resist to form a resist film, a semiconductor manufacturing device that develops a resist film, etc., the wafer The rotating side supplies water or chemical solution to the wafer. Or, by rotating the wafer to shake off the water or chemical solution on the wafer, the wafer is dried. Therefore, there is water or chemical liquid scattered around the wafer. The injection molded product of the present invention can be used as a wafer cup, and can be placed around the wafer to prevent water or chemical liquid from scattering. Wafer cups are sometimes called protective cups, splash guards, etc. Since the injection molded product of the present invention is difficult to charge, for example, even if it is arranged to surround the wafer, there is almost no possibility of charging the wafer or splashing charged liquid droplets on the wafer. Therefore, it can greatly contribute to improving the yield of semiconductor device manufacturing.

In addition, the molded product and the injection molded product of the present invention can be used as, for example, a member provided in a device for implementing the previous step of a semiconductor. As the steps before the semiconductor, the following steps can be cited. a. The "cleaning step" for cleaning the silicon wafer as the substrate b. "Film forming step" to form a thin film as a circuit material on a silicon wafer c. "Resist coating step" for uniformly coating photoresist (photosensitive liquid) d. "Exposure step" for transferring circuit patterns e. "Development step" to dissolve the photoresist in the exposed part f. "Etching step" to remove the film of the substrate exposed by the chemical liquid or ions g. "Ion implantation step" to implant phosphorus and other impurities to make silicon have electrical properties h. "Peeling step" to remove excess photoresist

To implement these steps, a semiconductor cleaning device or a semiconductor manufacturing device that processes wafers with water or chemical solution is used. By using the molded article or injection molded article of the present invention to form at least a part of the surface in contact with water or chemicals in a semiconductor cleaning device or semiconductor manufacturing device, the semiconductor cleaning device or semiconductor manufacturing device can be durable against water or chemicals Improved performance and suppress the adverse effects on semiconductor devices caused by static electricity.

As a preferable application of the molded product and the injection molded product of the present invention, piping of the chemical liquid supply equipment for semiconductor manufacturing, pipes for semiconductor manufacturing equipment, joints, valves, tanks, containers, chemical liquid bags, Perfluorinated fluororesin components such as wafer carriers.

The molded product of the present invention is not limited to the injection molded product, and the shape is not limited. The shape of the molded article of the present invention is not particularly limited, and examples thereof include pellets, films, sheets, plates, rods, blocks, cylinders, containers, wires, tubes, and the like. In addition, it can also be used to form the coating layer of cooking utensils such as inner pots, heating plates, and frying pans of electric pans, or fixed rollers for image forming devices such as photocopiers and laser printers using electrophotographic or electrostatic recording methods. Fluorine resin coating film such as the top coat. The fluororesin coating film can be formed by applying a coating material containing a fluoropolymer composition to a substrate.

The molded product and injection molded product of the present invention are not particularly limited. For example, they can be applied to the following applications: Diaphragm parts of diaphragm pumps, corrugated tube molded products, wire coating products, semiconductor parts, compression seals, thin-walled tubes for copy rolls, monofilaments, tapes, gaskets, optical lens parts, petroleum exploration tubes, geothermal power generation Pipes, wires for petroleum exploration, wires for satellites, wires for nuclear power generation, wires for airplanes, solar panel films, gaskets such as secondary batteries or electric double layer capacitors, OA rollers, etc.

In addition, the above-mentioned molded products and injection molded products can be preferably used in: tubes for the circulation of gas or liquid medicine, bottles for storing medicines, inflatable bags, liquid medicine bags, liquid medicine containers, bags for cryopreservation, etc. .

In addition, the above-mentioned molded products and injection molded products can be preferably used for the main body or parts of the opening and closing valve, the sleeves used when connecting the joint and the pipe, the screw cap of the liquid medicine bottle or the container, and the gears, Screws, frying pans, pots, electric pans, products coated with fluororesin on metal substrates, mold release films, etc.

The embodiments have been described above, but it should be understood that various changes in the form or details can be made without departing from the spirit and scope of the patent application. [Example]

Next, examples are given to describe the embodiments of the present invention, but the present invention is not limited to these examples.

Each numerical value of the embodiment is measured by the following method.

(Melting point) Use a differential scanning calorimeter [DSC] to find the temperature corresponding to the maximum value in the melting heat curve when the temperature is increased at a rate of 10°C/min.

(MFR) According to ASTM D1238, using a melt index tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.), the mass of polymer flowing out every 10 minutes from a nozzle with an inner diameter of 2 mm and a length of 8 mm under a load of 5 kg at 372°C (G/10 minutes).

(The content of monomer unit) The content of each monomer unit is measured by ¹⁹ F-NMR method.

(Volume resistivity) Use a film with a thickness of 0.25~0.3 mm obtained by forming a fluoropolymer composition, according to ASTM D 991 when measuring low-resistance areas, and according to ASTM D 257 when measuring high-resistance areas, at room temperature 23°C, humidity 50% Under the environment, use a high-precision resistivity meter or a multi-purpose high-resistivity meter to measure the volume resistivity.

The following materials were used in the examples. Copolymer 1: TFE/PPVE copolymer, composition ratio of TFE and PPVE (TFE/PPVE)=94.5/5.5 (mass%), melting point 304℃, MFR28 g/10 minutes Carbon 1: Carbon nanotubes, fiber diameter is 15 nm, fiber length is 200 μm Carbon 2: Carbon nanotubes, fiber diameter of 150 nm, fiber length of 9 μm Carbon 3: Ketjen Black, with an average particle diameter of 40 nm

Example 1 Using a Henschel mixer, copolymer 1 and carbon 1 were mixed so that the content of carbon 1 became the amount described in Table 1, to obtain a mixture. Put the obtained mixture into a screw extruder (shaft diameter 32 mm, L/D=52.5), melt the copolymer 1 in the cylinder, and extrude it from the die nozzle. Next, the strands extruded from the die nozzle are put into a water tank provided at a certain distance from the die nozzle, and after cooling, they are fed to a pelletizer and cut by a cutter to prepare pellets. Furthermore, the steps of melting the obtained pellets to prepare pellets were repeated 3 times to uniformly disperse carbon 1 in the fluoropolymer composition (particles), and to adjust the MFR of the fluoropolymer composition. The obtained particles are cylindrical with a length of 3.0 mm and a diameter of 2.0 mm. The MFR of the obtained particles was determined by the above method. The results are shown in Table 1. Furthermore, the obtained pellets were melted at 330~340°C for 30 minutes and compression-molded to produce a film with a thickness of 0.25~0.3 mm. The volume resistivity of the obtained film was measured by the above method. The results are shown in Table 1.

Examples 2 to 8, Comparative Examples 1 to 5 Except for changing the type and content of the conductive carbon compound as shown in Table 1, particles were prepared in the same manner as in Example 1, and a film was produced. However, when using carbon 1 or carbon 2 as the conductive carbon compound, repeat the steps of melting the obtained particles to prepare particles multiple times, so that carbon 1 or carbon 2 is uniformly dispersed in the fluoropolymer composition (particles) And, adjust the MFR of the fluoropolymer composition. The evaluation results are shown in Table 1. Furthermore, in Table 1, "aE+b" as the value of volume resistivity represents a×10 ^b . That is, for example, "1.0E+16" is a=1.0, b=16, which means 1.0×10 ¹⁶ , and "1.8E+05" is a=1.8, b=5, which means 1.8×10 ⁵ .

[Table 1] Conductive carbon compound Fluoropolymer composition species Content (mass%) Volume resistivity (Ω·cm) MFR (g/10 minutes) Comparative example 1 Carbon 1 0.01 1.0E+16 35 Example 1 Carbon 1 0.03 1.0E+08 40 Example 2 Carbon 1 0.04 1.0E+07 42 Example 3 Carbon 1 0.05 1.0E+05 45 Comparative example 2 Carbon 1 0.10 1.0E+03 50 Comparative example 3 Carbon 2 2.20 1.4E+14 60 Comparative example 4 Carbon 2 2.50 1.5E+10 65 Example 4 Carbon 2 3.00 1.8E+05 70 Example 5 Carbon 2 4.00 1.4E+04 80 Comparative example 5 Carbon 3 5.00 1.5E+13 twenty four Example 6 Carbon 3 7.50 1.5E+06 twenty three Example 7 Carbon 3 8.00 3.4E+05 twenty two Example 8 Carbon 3 10.00 2.4E+04 twenty one

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Claims (6)

A fluoropolymer composition comprising: a copolymer containing tetrafluoroethylene units and fluoroalkyl vinyl ether units, and a conductive carbon compound, relative to all monomer units constituting the copolymer, the fluoroalkyl vinyl ether The unit content is 5.0-8.0% by mass, the volume resistivity of the fluoropolymer composition is 10 ^{4 to} 10 ⁹ Ω·cm, and the melt flow rate of the fluoropolymer composition is 1 to 100 g/10 minutes. The fluoropolymer composition of claim 1, wherein the copolymer is at least one selected from the group consisting of the following copolymers: Copolymers composed only of tetrafluoroethylene units and fluoroalkyl vinyl ether units, and 0.1~10% by mass of monomer units derived from monomers copolymerizable with tetrafluoroethylene and fluoroalkyl vinyl ether, and a total of 90~99.9% by mass copolymers of tetrafluoroethylene units and fluoroalkyl vinyl ether units . The fluoropolymer composition of claim 1 or 2, wherein the conductive carbon compound is at least one selected from the group consisting of conductive carbon black and carbon nanotubes. The fluoropolymer composition according to any one of claims 1 to 3, wherein the content of the conductive carbon compound is 0.02-15% by mass relative to the fluoropolymer composition. A molded product obtained by molding the fluoropolymer composition of any one of claims 1 to 4. An injection molded product obtained by injection molding the fluoropolymer composition of any one of claims 1 to 4.