JP2021082373A - Diselectrification tube and method for manufacturing the same - Google Patents

Abstract

To provide a diselectrification tube having a superior antistatic performance, which shows a superior static elimination performance while preventing the elution of impurities (metal ions, organic material, etc.), and a method for manufacturing the same.SOLUTION: A diselectrification tube comprises a fluorine resin composition in which carbon nanotube is dispersed in a fluorine resin. The fluorine resin composition contains 0.01-2.0 wt.% of carbon nanotube. The diselectrification tube can be suitably used for a tube, nozzle, shower head, spray nozzle, rotary nozzle, liquid discharge part, pipe member, liquid-transfer tube, liquid-transfer joint and lining pipe, through which a fluid passes.SELECTED DRAWING: None

Description

The present invention relates to a static eliminator tube and a method for manufacturing the same, and more specifically, the static eliminator tube and its manufacture which have excellent antistatic performance and exhibit excellent static eliminator performance while preventing elution of impurities (metal ions, organic substances, etc.). Regarding the method.

Since fluororesin is excellent in chemical resistance, stain resistance, and the like, it is often used as a material for parts and the like for distributing corrosive fluids, pure water, chemical solutions, and the like to semiconductor manufacturing equipment, pharmaceutical manufacturing equipment, and the like.
However, since fluororesin is generally classified as an insulating material, when a fluid comes into contact with a component manufactured by using fluororesin, it may be charged by friction.
Therefore, it is known that a conductive substance such as carbon black and iron powder is mixed with the fluororesin to impart conductivity to the fluororesin. However, since the conductive substance and the fluid come into contact with each other, metal ions, organic substances, etc. Is known to flow out into the fluid and contaminate the fluid.

Patent Document 1 discloses an antistatic fluororesin tube in which a fluororesin composition containing a conductive substance is embedded in the outer peripheral surface of a transparent fluororesin tube as a striped conductive portion along the longitudinal direction (). Patent Document 1 Summary, see FIGS. 1 to 3 etc.).

Patent Document 2 discloses an antistatic tube formed in a hollow tube shape by alternately arranging a conductive portion made of a fluororesin composition containing a conductive substance and a transparent portion made of a fluororesin (Patent). Reference 2 Summary, see FIGS. 1, 4, 6 etc.).

Patent Document 3 describes carbon nanotubes (Carbon Nano Tube, hereinafter also referred to as “CNT”) having a fiber length of 50 μm or more and 150 μm or less and a fiber diameter of 5 nm or more and 20 nm or less in an amount of 0.020% by weight or more and 0.030% by weight. A fluid device provided with a fluid flow path formed of a fluororesin material containing the following proportions can suppress charging due to friction between the fluid flow path and the fluid and contamination of the fluid due to contact between the fluid flow path and the fluid. (See Patent Document 3, claim 1, [0008] to [0009], [0033], etc.).

Japanese Unexamined Patent Publication No. 2003-4176 Japanese Unexamined Patent Publication No. 2008-82459 Japanese Patent No. 5987100

Since the tube of Patent Document 1 does not come into contact with the fluid and the conductive substance, the fluid is not contaminated, but there is a problem that antistatic performance cannot be expected.

Since the tube of Patent Document 2 comes into contact with the fluid and the conductive substance, antistatic performance can be obtained, but there is a problem that the fluid may be contaminated.

The fluid flow path of Patent Document 3 is excellent in preventing fluid from being charged and contaminating the fluid, but has a problem that it is difficult to meet the demand for further performance improvement in recent years.

Further, in recent years, in addition to "antistatic" of a fluid and "contamination prevention" of a fluid, "static elimination" of an already charged fluid is also required. Here, "antistatic" means to prevent static electricity from being generated in an electrically insulating material that is not charged and to be charged with static electricity, whereas "static electricity elimination" is already charged with static electricity. It differs in that it removes the static electricity from the electrically insulating material. Known "static elimination" methods include grounding, ionizers, and humidification.
Patent Documents 1 to 3 do not disclose or teach static elimination of those tubes and fluid flow paths.

Therefore, an object of the present invention is to provide a static elimination tube having excellent antistatic performance and exhibiting excellent static elimination performance while preventing the elution of impurities (metal ions, organic substances, etc.) and a method for producing the same. ..

As a result of diligent studies, the present inventors have excellent antistatic performance when using a fluororesin composition in which a specific amount of carbon nanotubes is dispersed in a fluororesin, and impurities (metal ions, organic substances, etc.) It was found that a static elimination tube showing excellent static elimination performance can be obtained while preventing the elution of the resin. Furthermore, they have found that such a static elimination tube can be suitably used for a fluid transfer device, and have completed the present invention.

That is, the present specification includes the following aspects.
[1] It is made of a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin.
The fluororesin composition is a static elimination tube containing 0.01 to 2.0% by weight of carbon nanotubes.
[2] The static elimination tube according to 1 above, wherein the carbon nanotube has an average length of 50 μm or more.
[3] The static elimination tube according to 1 or 2 above, which has a volume resistivity of ^{1 × 10 -1} to 1 × 10 ^{6 Ω · cm.}
[4] The fluororesin is polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (modified PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer. (FEP), ethylene / tetrafluoroethylene copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF). ), The static elimination tube according to any one of 1 to 3 above.
[5] The static elimination tube according to any one of 1 to 4 above, wherein the fluororesin of the fluororesin composition has an average particle size of 500 μm or less.
[6] Any of the above 1 to 5 used for pipes through which fluids pass, nozzles, shower heads, spray nozzles, rotary nozzles, liquid discharge parts, piping members, liquid transfer tubes, liquid transfer joints, and lining pipes. The described static elimination pipe.
[7] A fluid transfer device including the static elimination pipe according to any one of 1 to 6 above.
[8] A semiconductor manufacturing device, a drug manufacturing device, a drug transport device, a chemical manufacturing device, or a chemical transport device, including the transport device according to 7 above.
[9] The method for producing a static elimination tube according to any one of 1 to 6 above, which comprises compression molding a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin.
[10] Preparing a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin selected from PTFE and modified PTFE;
The fluororesin composition is placed in a mold, pressed and compressed to produce a preformed body;
To produce a molded product by firing the preformed product at a temperature equal to or higher than the melting point of the fluororesin composition;
The method for manufacturing a static elimination tube according to any one of 1 to 6 above, which comprises processing a molded body to manufacture a static elimination tube.
[11] Preparing a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin other than PTFE and modified PTFE;
The production of the static elimination tube according to any one of 1 to 6 above, which comprises heating the fluororesin composition and then pressurizing and compressing to obtain a molded body; and processing the molded body to obtain a static elimination tube. Method.

The static elimination tube of the embodiment of the present invention has excellent antistatic performance, and exhibits excellent static elimination performance while preventing the elution of impurities (metal ions, organic substances, etc.). Therefore, for example, pipes (or tubes) through which fluids such as semiconductor manufacturing equipment, pharmaceutical manufacturing equipment, and chemical manufacturing equipment pass, nozzles, shower heads, rotary cleaning nozzles, liquid discharge parts, piping members, liquid (or chemical liquid) transport tubes. , Liquid transport joints, lining pipes, etc. can be suitably used.

FIG. 1 shows an SEM image (10000 times) of a residue obtained by heating a part of the static elimination tube of Example 1 to 600 ° C. FIG. 2 schematically shows an evaluation device for fluid static elimination.

The present invention provides a new static elimination tube, which is:
It is made of a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin.
The fluororesin composition contains 0.01 to 2.0% by weight of carbon nanotubes.

The static elimination tube of the embodiment of the present invention is made of a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin.
In the present specification, the fluororesin composition contains a fluororesin and carbon nanotubes, and may contain other components as necessary, and is particularly limited as long as the static elimination tube of the present invention can be obtained. There is nothing.

In the present specification, the "fluororesin" is a resin usually understood as a fluororesin, and is not particularly limited as long as the static elimination tube intended by the present invention can be obtained.
Examples of such a fluororesin include polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (modified PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), and tetrafluoroethylene / hexafluoropropylene. Polymer (FEP), ethylene / tetrafluoroethylene copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF) and polyvinylidene fluoride At least one selected from (PVF) can be exemplified.

As the fluororesin, polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (modified PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP) , Ethylene / tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF) are preferred, polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (modified PTFE), tetra. Fluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) and polychlorotrifluoroethylene (PCTFE) are more preferable.

As the fluororesin, a commercially available product can be used. For example
As polytetrafluoroethylene (PTFE), M-12 (trade name), M-11 (trade name), and Polyflon PTFE-M (trade name) manufactured by Daikin Industries, Ltd.,
As modified polytetrafluoroethylene (modified PTFE), M-112 (trade name), M-111 (trade name), and Polyflon PTFE-M (trade name) manufactured by Daikin Industries, Ltd.,
As polychlorotrifluoroethylene (PCTFE), M-300PL (trade name), M-300H (trade name), and Neophron PCTFE (trade name) manufactured by Daikin Industries, Ltd.
Examples of the tetrafluoroethylene / perfluoroalkyl vinyl ether (PFA) include AP-230 (trade name), AP-210 (trade name), and neophron PFA (trade name) manufactured by Daikin Industries, Ltd.
Fluororesin can be used alone or in combination.

In the embodiment of the present invention, the fluororesin of the fluororesin composition has a particle morphology, preferably has an average particle size of 500 μm or less, more preferably 8 to 250 μm, and more preferably 10 to 10 μm. It is even more preferable to have an average particle size of 50 μm, and particularly preferably to have an average particle size of 10 to 25 μm.
When the fluororesin of the fluororesin composition has an average particle size of 500 μm or less, the fluororesin and the carbon nanotubes can be mixed more uniformly, so that the conductivity is further improved.

_{In the present specification, the average particle size of the particles is the average particle size D 50} (laser diffraction scattering) obtained by measuring the particle size distribution using a laser diffraction scattering type particle size distribution device (“MT3300II” manufactured by Nikkiso). The median diameter, which means the particle size at an integrated value of 50% in the particle size distribution obtained by the method).

In the present specification, the "carbon nanotube" is a substance usually understood as a carbon nanotube, and is not particularly limited as long as the static elimination tube intended by the present invention can be obtained.

Examples of such carbon nanotubes (also referred to as “CNTs”) include single-walled CNTs, multi-walled CNTs, and two-walled CNTs. Commercially available products can be used as carbon nanotubes, and for example, the CNT-uni (trade name) series manufactured by Taiyo Nippon Sanso Co., Ltd. can be used.
CNTs can be used alone or in combination.

In the embodiment of the present invention, the carbon nanotubes preferably have an average length of 50 μm or more, more preferably 70 to 250 μm, and even more preferably 100 to 200 μm. It is preferable to have an average length of 150 to 200 μm, particularly preferably.
When the CNT has an average length of 50 μm or more, the conductivity is further improved from the viewpoint that the conductive paths are easily connected, which is preferable.

In the present specification, the average length (or average fiber length) of CNT means the average length obtained from an image taken by SEM, as described in detail in Examples. That is, a part of the static elimination tube is heated to 300 ° C. to 600 ° C. and incinerated to obtain a residue (sample for SEM photography). An SEM image of the residue is taken. The length of each carbon nanotube included in the SEM image is obtained by image processing. The average value of the lengths obtained by the image processing is calculated, and the average value is called the average length of CNTs.

In the embodiment of the present invention, the fluororesin composition contains 0.01 to 2.0% by weight of carbon nanotubes, preferably 0.04 to 1.5% by weight, and preferably 0.05 to 1.0% by weight. It is more preferable to contain%, and it is particularly preferable to contain 0.05 to 0.5% by weight.
When the fluororesin composition contains 0.05 to 0.5% by weight of carbon nanotubes, the amount is sufficient to form a conductive path, so that the conductivity is further improved, which is preferable.

The static elimination tube of the embodiment of the present invention ^{preferably has a volume resistivity of 1 × 10 -1} to 1 × 10 ⁷ Ω · cm, and has a volume resistivity of 1 × 10 ⁰ to 1 × 10 ⁵ Ω · cm. It is more preferable to have a volume resistivity of ^{1 × 10 1} to 1 × 10 ^{3 Ω · cm.}
The measurement of volume resistivity is described in Examples.

The static elimination tube of the embodiment of the present invention is evaluated using the method described in Examples, and the charge residual ratio is preferably 70% or less, more preferably 50% or less, and 30% or less. Is even more preferable, and 20% or less is particularly preferable.
When the residual charge ratio is 20% or less, static electricity is suppressed, so that the non-dust collecting property is further improved, which is preferable.

In the static elimination tube of the embodiment of the present invention, the resistance having a length of 10 cm ^{is preferably 1 × 10 6} Ω or less, ^{more preferably 8 × 10 5} Ω or less, and 5 × 10 ⁵ Ω or less. It is even more preferable that there is 1 × 10 ⁵ Ω or less.
When the resistance having a length of 10 cm is 1 × 10 ⁵ Ω or less, the conduction is sufficiently obtained, so that the fluid static elimination property is further improved, which is preferable.

The static elimination pipe of the embodiment of the present invention is evaluated by the method described in the examples of the present specification, and the contamination prevention property is preferably less than 5 ppb and less than 1 ppb in the elution amount of all metals. More preferably, it is more preferably less than 0.5 ppb.
Further, the elution amount of total organic carbon is preferably less than 50 ppb, more preferably less than 40 ppb, and further preferably less than 30 ppb.

The static eliminator tube of the embodiment of the present invention can have various dimensions depending on its use, and the dimensions are not particularly limited as long as the static eliminator tube of the present invention can be obtained.
The static elimination tube has, for example, a cylindrical shape (or a tubular shape), and the outer diameter is preferably 4 to 500 mm, more preferably 6 to 250 mm, and even more preferably 6 to 75 mm. , 6 to 50 mm is particularly preferable. The wall thickness is preferably 0.5 to 50 mm, more preferably 1 to 20 mm, even more preferably 1 to 10 mm, and particularly preferably 1 to 5 mm.

The static eliminator of the embodiment of the present invention may be manufactured by any method as long as the static eliminator of the present invention can be obtained.
The static elimination tube of the embodiment of the present invention is preferably manufactured by a manufacturing method including compression molding of a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin.

The method for producing a static eliminator according to an embodiment of the present invention is a method for producing a static eliminator for PTFE and modified PTFE, and a method for producing a static eliminator for other fluororesins (for example, PFA, FEP, ETFE, ECTFE, PCTFE, PVDF and PVF). The manufacturing method is partially different.

The method for manufacturing a static elimination tube for PTFE and modified PTFE is as follows.
To prepare a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin (preferably particulate fluororesin);
The fluororesin composition is placed in a mold (after appropriate pretreatment (pre-drying, granulation, etc.) as necessary), preferably 0.1 to 100 MPa, more preferably 1 to 80 MPa. Even more preferably, the preformed body is produced by pressurizing and compressing at a pressure of 5 to 50 MPa;
The premolded article is fired at a temperature equal to or higher than the melting point of the fluororesin composition (preferably at a temperature of 345 to 400 ° C., more preferably 360 to 390 ° C.) for 2 hours or more to produce a molded article;
This includes processing (preferably cutting) a molded body to produce a static elimination tube.

A method for manufacturing a static elimination tube for fluororesins other than PTFE and modified PTFE (for example, PFA, FEP, ETFE, ECTFE, PCTFE, PVDF and PVF) is described.
To prepare a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin (preferably particulate fluororesin);
The fluororesin composition is placed in a mold, appropriately pretreated (pre-drying, etc.) as necessary, and then heated at a temperature of 150 to 400 ° C. for 1 to 5 hours, for example, 0.1 to 1. It includes compressing at a pressure of 100 MPa (preferably 1 to 80 MPa, more preferably 5 to 50 MPa) to obtain a molded product; and processing (preferably cutting) the molded product to obtain a static elimination tube. ..

The static eliminator of the present embodiment can be used for various purposes, and as long as the static eliminator of the present invention can be used, the use is not particularly limited, but for example, a fluid can be used. It can be used for passing pipes, nozzles, shower heads, spray nozzles, rotary nozzles, liquid discharge parts, piping members, liquid transfer tubes, liquid transfer joints, lining pipes and the like.

The present invention provides a fluid transfer device including a static elimination tube according to an embodiment of the present invention.
Furthermore, the present invention provides various equipment including such a fluid transfer device, for example, a semiconductor manufacturing device, a drug manufacturing device, a drug transport device, a chemical manufacturing device, a chemical transport device, and the like.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but these Examples are only one aspect of the present invention, and the present invention is not limited to these Examples.

The components used in this example are shown below.
(A) Fluororesin (A1) Polychlorotrifluoroethylene (Neoflon PCTFE (trade name) manufactured by Daikin Industries, Ltd.) (also referred to as "(A1) PCTFE")
(A2) Polytetrafluoroethylene (Polyflon PTFE-M (trade name) manufactured by Daikin Industries, Ltd.) (also referred to as "(A2) PTFE")
(A3) Modified polytetrafluoroethylene (Polyflon PTFE-M (trade name) manufactured by Daikin Industries, Ltd.) (also referred to as "(A3) modified PTFE")
(A4) Tetrafluoroethylene / Perfluoroalkyl Vinyl Ether (Neoflon PFA (trade name) manufactured by Daikin Industries, Ltd. (also referred to as "(A4) PFA"))

(B) Carbon nanotubes (B1) Carbon nanotubes (average fiber length = about 150 μm, CNT-uni (trade name) manufactured by Taiyo Nippon Sanso Co., Ltd.) (also referred to as “(B1) CNT”)
(B2) Carbon nanotubes (average fiber length = about 400 μm, CNT-uni (trade name) manufactured by Taiyo Nippon Sanso Co., Ltd.) (also referred to as “(B2) CNT”)
(B3) Carbon nanotubes (average fiber length = about 90 μm, CNT-uni (trade name) manufactured by Taiyo Nippon Sanso Co., Ltd.) (also referred to as “(B3) CNT”)
(B4) Carbon nanotubes (average fiber length = about 600 μm, CNT-uni (trade name) manufactured by Taiyo Nippon Sanso Co., Ltd.) (also referred to as “(B4) CNT”)
(B5)'Carbon nanotubes (average fiber length = about 30 μm, CNT-uni (trade name) manufactured by Taiyo Nippon Sanso Co., Ltd.) (also referred to as'(B5)'CNT')
Fluororesin containing carbon fiber (C1) PTFE containing carbon fiber (PB2515 made by Asahi Glass (trade name))

<Example 1>
(A1) Polychlorotrifluoroethylene (PCTFE) was pulverized using a pulverizer and classified by a vibrating sieve or the like to prepare (A1) PCTFE particles. The particle size distribution of (A1) PCTFE particles was measured using a laser diffraction / scattering type particle size distribution device (“MT3300II” manufactured by Nikkiso) to obtain _{the average particle size (D 50) of (A1) PCTFE particles.} (A1) The average particle size (D ₅₀ ) of the PCTFE particles was 11.5 μm.

3,500 g of ethanol was added to 500 g of a (B1) carbon nanotube dispersion liquid (dispersant = 0.15% by mass, (B1) carbon nanotube = 0.1% by mass) using water as a solvent to dilute the mixture. Further, 1000 g of the above-mentioned (A1) PCTFE particles were added to prepare a mixed slurry.
The mixed slurry is supplied to the pressure-resistant container, and liquefied carbon dioxide is supplied at a supply rate of 0.03 g / min to 1 mg of the dispersant contained in the mixed slurry in the pressure-resistant container. The pressure was increased and the temperature was raised to 50 ° C. While maintaining the above pressure and temperature for 3 hours, carbon dioxide was discharged from the pressure-resistant container together with the solvent (water, ethanol) dissolved in carbon dioxide and the dispersant.
The pressure and temperature in the pressure-resistant container were lowered to atmospheric pressure and room temperature, respectively, to remove carbon dioxide in the pressure-resistant container to obtain a (A1) PCTFE composition containing 0.1% by weight of (B1) carbon nanotubes. ..

The (A1) PCTFE composition was molded using a compression molding method to obtain a columnar molded product. That is, the (A1) PCTFE composition was placed in a mold, and if necessary, appropriate pretreatment (pre-drying, etc.) was performed. Then, the (A1) PCTFE composition is heated at a temperature of 200 ° C. or higher for 2 hours or longer, and then cooled to room temperature while compressing the (A1) PCTFE composition at a pressure of 5 MPa or higher (A1) PCTFE molded product. Got
(A1) The PCTFE molded body was cut to obtain a static elimination tube of Example 1 as a cylindrical (or tubular) molded body. The static elimination tube of Example 1 had a diameter (outer diameter) of about 40 mm, a wall thickness of about 15 mm, and a length of about 100 mm.

<Example 2>
(B1) The static elimination tube of Example 2 was manufactured by the same method as that described in Example 1 except that the carbon nanotubes were changed to contain 0.05% by weight.

<Example 3>
The static elimination tube of Example 3 was manufactured by using the same method as that described in Example 1 except that the carbon nanotube (B1) was changed to the carbon nanotube (B2).

<Example 4>
The static elimination tube of Example 4 was manufactured by the same method as that described in Example 1 except that the carbon nanotube (B1) was changed to the carbon nanotube (B3).

<Example 5>
(A2) Polytetrafluoroethylene (PTFE) was commercially available in the form of granules, and its average particle size (D ₅₀ ) was 50.4 μm. (A2) The average particle size (D ₅₀ ) of the PTFE particles was measured using the same method as that described in Example 1.

(A2) PTFE composition containing 0.1% by weight of (B1) carbon nanotubes using the same method as described in Example 1 except that the (A1) PCTFE particles were changed to (A2) PTFE particles. I got something.

The (A2) PTFE composition was molded using the compression molding method to obtain a columnar molded product. That is, the (A2) PTFE composition was pretreated (pre-dried, etc.) as necessary, and then the (A2) PTFE composition was uniformly filled in a mold in a fixed amount. The (A2) PTFE composition was pressurized at 15 MPa and held for a certain period of time to compress the (A2) PTFE composition to obtain a (A2) PTFE preformed body. The (A2) PTFE preformed body was taken out from the mold, fired in a hot air circulation type electric furnace set at 345 ° C. or higher for 2 hours or more, slowly cooled, and then taken out from the electric furnace to obtain a (A2) PTFE molded body. (A2) The PTFE molded body was cut to obtain a static elimination tube of Example 5 as a cylindrical molded body. The static elimination tube of Example 5 had a diameter of about 40 mm, a wall thickness of about 15 mm, and a length of about 100 mm.

<Example 6>
(B1) The static elimination tube of Example 6 was manufactured by the same method as that described in Example 5 except that the carbon nanotubes were changed to contain 0.025% by weight.

<Example 7>
(A3) Modified polytetrafluoroethylene (modified PTFE) was commercially available in the form of granules, and its average particle size (D ₅₀ ) was 19.6 μm. (A3) The average particle size (D ₅₀ ) of the PTFE particles was measured using the same method as that described in Example 1.

Using the same method as that described in Example 1 except that the (A1) PCTFE particles were changed to (A3) modified PTFE particles, the (B1) carbon nanotubes were contained in an amount of 0.1% by weight (A3). A PTFE composition was obtained.

The (A3) modified PTFE composition was molded using a compression molding method to obtain a columnar molded product. That is, the (A3) modified PTFE composition was pretreated (pre-dried, etc.) as necessary, and then the (A3) modified PTFE composition was uniformly filled in a mold in a fixed amount. The (A3) modified PTFE composition was pressurized at 15 MPa and held for a certain period of time to compress the (A3) modified PTFE composition to obtain a (A3) modified PTFE preformed body. The (A3) modified PTFE preformed body is taken out from the mold, fired in a hot air circulation type electric furnace set at 345 ° C. or higher for 2 hours or more, slowly cooled, and then taken out from the electric furnace to obtain a (A3) modified PTFE molded product. It was. (A3) The modified PTFE molded body was cut to obtain a static elimination tube of Example 7 as a cylindrical molded body. The static elimination tube of Example 7 had a diameter of about 40 mm, a wall thickness of about 15 mm, and a length of about 100 mm.

<Example 8>
The (A4) tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) was pulverized using a pulverizer and classified by a vibrating sieve or the like to prepare (A4) PFA particles. The average particle size (D ₅₀ ) of the (A4) PFA particles was 121.7 μm. (A4) The average particle size (D ₅₀ ) of the PFA particles was measured using the same method as that described in Example 1.

(A4) PFA composition containing 0.1% by weight of (B1) carbon nanotubes using the same method as described in Example 1 except that the (A1) PCTFE particles were changed to (A4) PFA particles. I got something.

The (A4) PFA composition was molded using a compression molding method to obtain a columnar molded product. That is, the (A4) PFA composition was placed in a mold, and if necessary, appropriate pretreatment (pre-drying, etc.) was performed. Then, the (A4) PFA composition is heated at a temperature of 300 ° C. or higher for 2 hours or longer, and then cooled to room temperature while compressing the (A4) PFA composition at a pressure of 5 MPa or higher to cool the (A4) PFA molded product. Got
(A4) The PFA molded body was cut to obtain a static elimination tube of Example 8 as a cylindrical (or tubular) molded body. The static elimination tube of Example 8 had a diameter (outer diameter) of about 40 mm, a wall thickness of about 15 mm, and a length of about 100 mm.

<Comparative example 1>
Using the melt-kneading method, a (A1) PCTFE composition containing 0.1% by weight of (B1) carbon nanotubes was molded to obtain a cylindrical molded product. That is, (A1) the PCTFE composition is put into an extruder, appropriately pretreated (pre-drying, etc.) as necessary, extruded with a screw at a cylinder temperature of 200 ° C. or higher, and shaped using a sizing die. (A1) PCTFE molded product was obtained. (A1) The PCTFE molded body was cut to produce a static elimination tube of Comparative Example 1 as a cylindrical molded body. The static elimination tube of Comparative Example 1 has a diameter of about 40 mm, a wall thickness of about 15 mm, and a length of about 100 mm.

<Comparative example 2>
Comparative Example 2 static elimination tube was manufactured by using the same method as that described in Example 1 except that the carbon nanotube (B1) was changed to the carbon nanotube (B4).

<Comparative example 3>
The (C1) carbon fiber-containing PTFE (carbon fiber 15% by weight) composition was commercially available in the form of granules, and the average particle size (D ₅₀ ) was 630 μm. The average particle size (D ₅₀ ) of the PTFE composition was measured using the same method as described in Example 1.

This PTFE composition was molded using a compression molding method to obtain a columnar molded body. That is, the PTFE composition was pretreated (preliminarily dried, etc.) as necessary, and then the PTFE composition was uniformly filled in a mold in a fixed amount. By pressurizing the PTFE composition at 15 MPa and holding it for a certain period of time, the PTFE composition was compressed to obtain a PTFE preformed body. The PTFE preformed body was taken out from the mold, fired in a hot air circulation type electric furnace set at 345 ° C. or higher for 2 hours or more, slowly cooled, and then taken out from the electric furnace to obtain a PTFE molded body. The PTFE molded body was cut to obtain a static elimination tube of Comparative Example 3 as a cylindrical molded body. The static elimination tube of Comparative Example 3 had a diameter of about 40 mm, a wall thickness of about 15 mm, and a length of about 100 mm.

<Average fiber length>
The average fiber length of the carbon nanotubes contained in the static elimination tube was evaluated by taking an image of the static elimination tube using SEM (VE-9800 (trade name) manufactured by KEYENCE). A part of the static elimination tube was incinerated by using the ashing method to prepare a sample for imaging. That is, a part of the static elimination tube was heated to 300 ° C. to 600 ° C. and incinerated to obtain a residue. The residue was used as a sample for imaging, and SEM (scanning electron microscope) observation was performed. For example, an SEM image of the static elimination tube of Example 1 is shown in FIG. The fiber length of the fiber of each carbon nanotube contained in the image was obtained by image processing, and the average value of the fiber length values was calculated and obtained. The results are shown in Table 1.

<Static elimination based on resistance>
The static elimination property and antistatic property based on the resistance value were evaluated based on ISO8031: 2009. That is, metal joints were connected to each of both ends of the static elimination pipe. The resistance value between the two metal joints was measured using an insulation resistance meter (3-range insulation resistance meter (trade name) manufactured by Musashi Denki Keiki Seisakusho). For example, the resistance value of the static elimination tube of Example 2 was 2 × 10 ⁴ Ω.

The evaluation criteria for static elimination are as follows.
◯: The resistance value between 10 cm is 1 × 10 ⁶ Ω or less.
X: The resistance value between 10 cm ^{exceeds 1 × 10 6} Ω.
The static elimination pipe of Example 1 was evaluated to have good static elimination properties. The results are shown in Table 1.

<Pollution prevention>
Measurement of the amount of metal elution in the static elimination tube The degree of metal contamination in the static elimination tube was measured using an ICP mass spectrometer (“ELAN DRCII” manufactured by PerkinElmer) with 17 metal elements (Li, Na, Mg, Al, K, Ca, It was evaluated by measuring the metal elution amount of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd and Pb).
A test piece having a size of 10 mm × 20 mm × 50 mm was cut and obtained from a cylindrical molded body obtained by compression molding. The test piece was immersed in 0.5 L of 3.6% hydrochloric acid (EL-UM grade manufactured by Kanto Chemical Co., Inc.) for about 1 hour, and then washed with ultrapure water (specific resistance value: ≧ 18.0 MΩ · cm). .. Further, the entire test piece was immersed in 0.1 L of 3.6% hydrochloric acid and stored in a room temperature environment for 24 hours and 168 hours. After the lapse of the specified time, the entire amount of the immersion liquid was recovered (the entire amount of the immersed hydrochloric acid was collected), and the concentration of metal impurities in the immersion liquid was analyzed. Three test pieces were prepared, and the maximum value was used as the detection amount.
The evaluation criteria are as follows.
⊚: The detected amount of all metals is less than 5 ppb.
◯: The detected amounts of Al, Cr, Cu, Fe, Ni, Zn, Ca, K and Na are less than 5 ppb.
Δ: The amount of Al, Cr, Cu, Fe, Ni and Zn detected is less than 5 ppb.
X: The detection amount of any one of Al, Cr, Cu, Fe, Ni and Zn is 5 ppb or more.
The results are shown in Table 1. The numerical values are shown in Table 2.

Measurement of carbon loss in static elimination tube The degree of carbon nanotube detachment from the static elimination tube was evaluated by measuring TOC (total organic carbon) using a total organic carbon meter (“TOCvww” manufactured by Shimadzu Corporation). .. Specifically, a test piece of 10 mm × 20 mm × 50 mm obtained by cutting from a cylindrical molded body obtained by compression molding is placed in 3.5 L of 3.6% hydrochloric acid (EL-UM grade manufactured by Kanto Chemical Co., Inc.) for about 1 hour. Immerse it, soak it for 1 hour, take it out, flush it with ultrapure water (specific resistance value: ≧ 18.0 MΩ · cm), wash it, and immerse the entire test piece in ultrapure water for 24 hours and 168 at room temperature. Saved time. After the lapse of the specified time, the entire immersion liquid was recovered (the entire amount of the immersed ultrapure water was collected), and the immersion liquid was subjected to total organic carbon analysis. Three test pieces were prepared, and the maximum value was used as the detection amount.
The evaluation criteria are as follows.
◯: The amount of total organic carbon detected is less than 50 ppb.
X: The amount of total organic carbon detected is 50 ppb or more.

<Fluid static elimination>
The outline of the fluid static elimination evaluation device is schematically shown in FIG. The pure water pipe from the pure water production apparatus is connected to the PFA pipe. A static elimination pipe was connected to the end of the PFA pipe. The static eliminator is connected to ground. A nozzle was connected to the end of the static elimination tube. The nozzle is a processed PCTFE and has a hole in the center. The nozzle hole has an inner diameter of 3 mm and a length of 10 mm. The receiver under the nozzle constitutes a Faraday cage. The receiver has a double cylindrical structure, and is a cylindrical container having an outer diameter of 14 cm and a height of 20 cm on the outside and a cylindrical container having a diameter of 10 cm and a height of 15 cm on the inside. Both materials are stainless steel. The inner cylindrical container is insulated from the ground by PTFE. The shield is a rectangular parallelepiped with a base of 50 cm x 50 cm and a height of 1 m, and a brass wire mesh is attached to the frame of the angle. The PFA piping and receiver were placed inside the shield, and the receiver was placed approximately in the center of the shield.
The distance between the nozzle and the upper lid of the receiver was 10 cm, and the hole in the upper lid was square and 5 cm × 5 cm.
The amount of electric charge of pure water that passed through the nozzle without the static elimination pipe connected and the amount of electric charge of pure water that passed through the nozzle with each static elimination pipe connected were measured. The flow rate of pure water is 2 m / sec.
The amount of electric charge (Q1) of pure water that passed through the nozzle without the static elimination pipe connected and the amount of electric charge (Q) of pure water that passed through the nozzle with the static elimination tube connected were measured.
The amount of charge was measured using an electrometer (6514 type (trade name) manufactured by KEYTHLEY).
Charge residual rate: (Q / Q1) × 100 was determined.
The evaluation criteria are as follows.
⊚: The residual charge rate is 30% or less.
◯: The residual charge rate exceeds 30% and is 50% or less.
Δ: The residual charge rate exceeds 50% and is 70% or less.
X: The residual charge rate exceeds 70%.

<Volume resistivity>
Using the same method as the compression molding method described above, a test piece having a diameter of 110 × 10 mm was prepared for each Example and Comparative Example, and used as a measurement sample.
The volume resistivity was measured using a resistivity meter (“Lorester” or “High Lester” manufactured by Mitsubishi Chemical Analytech) according to JIS K6911.
The evaluation criteria are as follows.
⊚: The volume resistivity is 1 × 10 ³ Ω · cm or less.
◯: The volume resistivity ^{exceeds 1 × 10 3} Ω · cm and is 1 × 10 ⁵ Ω · cm or less.
Δ: The volume resistivity ^{exceeds 1 × 10 5} Ω · cm and is 1 × 10 ⁷ Ω · cm or less.
×: volume resistivity greater than 1 × 10 ⁷ Ω · cm.

ａ）溶融混練法を使用した。
ｂ）体積抵抗率が、測定上限を超えた為、測定できなかった。

a) The melt kneading method was used.
b) The volume resistivity exceeded the upper limit of measurement and could not be measured.

The present invention is made of a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin, and the fluororesin composition provides a new static elimination tube containing 0.01 to 2.0% by weight of carbon nanotubes.
The static elimination tube has excellent antistatic performance, and exhibits excellent static elimination performance while preventing the elution of impurities (metal ions, organic substances, etc.). Therefore, for example, pipes (or tubes) through which fluids such as semiconductor manufacturing equipment, pharmaceutical manufacturing equipment, and chemical manufacturing equipment pass, nozzles, shower heads, rotary cleaning nozzles, liquid discharge parts, piping members, liquid (or chemical liquid) transport tubes. , Liquid transport joints, lining pipes, etc. can be suitably used.

Claims (11)

It is made of a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin.
The fluororesin composition is a static elimination tube containing 0.01 to 2.0% by weight of carbon nanotubes. The static elimination tube according to claim 1, wherein the carbon nanotube has an average length of 50 μm or more. The static elimination tube according to claim 1 or 2, which has a volume resistivity of 1 × 10 ^-1 to 1 × 10 ^{6 Ω · cm.} Fluororesin is polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (modified PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP). , Ethylene / tetrafluoroethylene copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF) The static elimination tube according to any one of claims 1 to 3, which comprises at least one kind. The static elimination tube according to any one of claims 1 to 4, wherein the fluororesin of the fluororesin composition has an average particle size of 500 μm or less. The invention according to any one of claims 1 to 5, which is used for a pipe through which a fluid passes, a nozzle, a shower head, a spray nozzle, a rotary nozzle, a liquid discharge part, a piping member, a liquid transfer tube, a liquid transfer joint, and a lining pipe. Static elimination pipe. A fluid transfer device including the static elimination pipe according to any one of claims 1 to 6. A semiconductor manufacturing device, a drug manufacturing device, a drug transport device, a chemical manufacturing device, or a chemical transport device, including the transport device according to claim 7. The method for producing a static elimination tube according to any one of claims 1 to 6, wherein the fluororesin composition in which carbon nanotubes are dispersed in the fluororesin is compression-molded. To prepare a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin selected from PTFE and modified PTFE;
The fluororesin composition is placed in a mold, pressed and compressed to produce a preformed body;
To produce a molded product by firing the preformed product at a temperature equal to or higher than the melting point of the fluororesin composition;
The method for manufacturing a static elimination tube according to any one of claims 1 to 6, which comprises processing a molded body to manufacture a static elimination tube. To prepare a fluororesin composition in which carbon nanotubes are dispersed in a fluororesin other than PTFE and modified PTFE;
The static elimination tube according to any one of claims 1 to 6, wherein the fluororesin composition is heated and then pressurized and compressed to obtain a molded body; and the molded body is processed to obtain a static elimination tube. Production method.

Images