WO2011077597A1

WO2011077597A1 - Sealing member

Info

Publication number: WO2011077597A1
Application number: PCT/JP2009/071906
Authority: WO
Inventors: 徹野口; 宏之植木; 茂樹犬飼; 正栄伊藤; ラグーマーダーウェン; 守信遠藤; 悟史飯生
Original assignee: 日信工業株式会社; シュルンベルジェテクノロジーベーフェー; セルヴィスペトロリエシュルンベルジェ; シュルンベルジェカナダリミテッド; シュルンベルジェホールディングスリミテッド; プラッドリサーチアンドデベロプメントリミテッド; 国立大学法人信州大学; Mefs株式会社
Priority date: 2009-12-25
Filing date: 2009-12-25
Publication date: 2011-06-30
Also published as: JP5592401B2; JPWO2011077597A1

Abstract

Disclosed is a sealing member comprising a tetrafluoroethylene-propylene copolymer (FEPM) and carbon nanofibers. The sealing member has a number of cycles to fracture of 10 or more in a tensile fatigue test at 150˚C, a maximum tensile stress of 2 N/mm and a frequency of 1 Hz. The sealing member has excellent heat resistance and abrasion resistance.

Description

Seal member

The present invention relates to a seal member.

According to the method for producing a carbon fiber composite material previously proposed by the present inventors, by using an elastomer, the dispersibility of the carbon nanofiber, which has been considered difficult so far, is improved, and the carbon nanofiber is uniformly distributed in the elastomer. (See, for example, JP-A-2005-97525). According to such a method for producing a carbon fiber composite material, an elastomer and carbon nanofibers are kneaded, and dispersibility of carbon nanofibers having high cohesiveness is improved by shearing force. More specifically, when the elastomer and the carbon nanofiber are mixed, the viscous elastomer penetrates into the carbon nanofiber, and a specific part of the elastomer has high activity of the carbon nanofiber due to chemical interaction. In this state, when a strong shearing force is applied to a mixture of an elastomer having high molecular mobility (elasticity) and carbon nanofibers, the carbon nanofibers are deformed as the elastomer is deformed. The fibers also moved, and the aggregated carbon nanofibers were separated and dispersed in the elastomer by the restoring force of the elastomer due to elasticity after shearing. Thus, by improving the dispersibility of the carbon nanofibers in the matrix, expensive carbon nanofibers can be used efficiently as fillers for composite materials.

An object of the present invention is to provide a seal member excellent in heat resistance and wear resistance.

The sealing member according to the present invention is
For tetrafluoroethylene-propylene copolymer (FEPM), including carbon nanofibers,
The number of breaks in a tensile fatigue test at 150 ° C., a maximum tensile stress of 2 N / mm, and a frequency of 1 Hz is 10 times or more.

In the sealing member according to the present invention,
With respect to 100 parts by mass of the tetrafluoroethylene-propylene copolymer (FEPM), 0.5 part by mass to 30 parts by mass of the carbon nanofiber, and 0 part by mass to 50 parts by mass of a filler having an average particle diameter of 5 nm to 300 nm; Including,
The carbon nanofiber has an average diameter of 10 nm to 20 nm,
The compounding quantity of the said carbon nanofiber and the said filler can satisfy | fill following formula (1) and (2).
Wt = 0.09W1 + W2 (1)
5 ≦ Wt ≦ 30 (2)
W1: Blending amount of filler (parts by mass)
W2: Compounding amount (parts by mass) of carbon nanofibers.

In the sealing member according to the present invention,
The number of breaks in a tensile fatigue test at 150 ° C., a maximum tensile stress of 2 N / mm, and a frequency of 1 Hz can be 1,000 times or more.

In the sealing member according to the present invention,
4 parts by mass to 30 parts by mass of the carbon nanofibers and 0 part by mass to 60 parts by mass of a filler having an average particle diameter of 5 nm to 300 nm with respect to 100 parts by mass of the tetrafluoroethylene-propylene copolymer (FEPM). Including
The carbon nanofiber has an average diameter of 60 nm to 110 nm,
The compounding quantity of the said carbon nanofiber and the said filler can satisfy | fill following formula (3) and (4).
Wt = 0.1W1 + W2 (3)
10 ≦ Wt ≦ 30 (4)
W1: Blending amount of filler (parts by mass)
W2: Compounding amount (parts by mass) of carbon nanofibers.

In the sealing member according to the present invention,
The compression set after 25 hours of compression and 70 hours at 200 ° C. can be 0% to 40%.

In the sealing member according to the present invention,
The wear amount Wa in a high-pressure wear test at 25 ° C. is 0.010 cm ³ / N · m to 0.070 cm ³ / N · m,
The wear amount Wa can satisfy the following formula (5).
Wa = (g ₂ −g ₁ ) / (P · L · d) (5)
g ₁ : Mass of the test piece before wear (g)
g ₂ : Mass of the test piece after wear (g)
P: Set weight of weight (N)
L: Wear distance (m)
d: Specific gravity (g / cm ³ ).

In the sealing member according to the present invention,
The seal member can be used in an oil field device.

In the sealing member according to the present invention,
The oil field device may be a logging device that performs logging in a well.

In the sealing member according to the present invention,
The seal member may be an endless seal member disposed in the oil field device.

In the sealing member according to the present invention,
The seal member may be a stator of a fluid drive motor disposed in the oil field device.

In the sealing member according to the present invention,
The fluid drive motor may be a mud motor.

In the sealing member according to the present invention,
The seal member may be a rotor of a fluid drive motor disposed in the oil field device.

In the sealing member according to the present invention,
The tetrafluoroethylene-propylene copolymer (FEPM) has a fluorine content of 50 to 60% by mass, a central value of Mooney viscosity (ML _{1 + 4} 100 ° C.) of 90 to 160, and a glass transition point of 0 ° C. or less. Can do.

In the sealing member according to the present invention,
Before the carbon nanofibers are blended with the tetrafluoroethylene-propylene copolymer (FEPM), rigidity = Lx ÷ D (Lx: distance between adjacent defects of the carbon nanofibers) , D: the diameter of the carbon nanofiber), the average value of the stiffness can be 3-12.

In the sealing member according to the present invention,
The filler may be carbon black having an average particle size of 10 nm to 300 nm.

In the sealing member according to the present invention,
The filler may have an average particle diameter of 5 nm to 50 nm and at least one selected from silica, talc and clay.

FIG. 1 is a perspective view schematically showing a compression process of carbon nanofibers used in a sealing member according to an embodiment of the present invention. Drawing 2 is a figure showing typically the manufacturing method of the sealing member by the open roll method concerning one embodiment of the present invention. Drawing 3 is a figure showing typically the manufacturing method of the sealing member by the open roll method concerning one embodiment of the present invention. FIG. 4 is a diagram schematically showing a method for manufacturing a seal member by an open roll method according to an embodiment of the present invention. FIG. 5 is a diagram schematically showing a tensile fatigue test of the seal member according to the embodiment of the present invention. FIG. 6 is a diagram schematically showing a high-pressure wear test of the seal member according to the embodiment of the present invention. FIG. 7 is a cross-sectional view schematically showing a logging tool for seabed use according to an embodiment of the present invention. FIG. 8 is a partial cross-sectional view schematically showing the logging apparatus of FIG. 7 according to one embodiment of the present invention. FIG. 9 is an X-X ′ cross-sectional view schematically showing a mud motor of the logging apparatus of FIG. 8. FIG. 10 is a cross-sectional view schematically showing an underground logging tool according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail.
The seal member according to one embodiment of the present invention includes carbon nanofibers with respect to tetrafluoroethylene-propylene copolymer (FEPM), and breaks in a tensile fatigue test at 150 ° C., a maximum tensile stress of 2 N / mm, and a frequency of 1 Hz. The number of times is 10 times or more.

(I) Carbon nanofiber The carbon nanofiber will be described.
The carbon nanofibers used in the present embodiment can have an average diameter (fiber diameter) of 10 nm to 110 nm, and can further have an average diameter of 10 nm to 20 nm or an average diameter of 60 nm to 110 nm. Since the carbon nanofiber has a relatively small average diameter, the specific surface area is large, the surface reactivity with the matrix FEPM is improved, and the carbon nanofiber in the FEPM tends to be poorly dispersed. Carbon nanofibers are expected to have moderate flexibility with a microcell structure formed so as to surround the matrix material with carbon nanofibers when the diameter is 10 nm or more. Conversely, when the diameter is 110 nm or less, the microcell structure is large. However, it is expected to have an effect of wear resistance. The micro cell structure formed by the carbon nanofibers can be formed so as to surround the matrix material by a network structure in which the carbon nanofibers are stretched in three dimensions. Carbon nanofibers having an average diameter of 60 nm to 110 nm can further be 70 nm to 100 nm. In addition, carbon nanofibers having an average diameter of 60 nm to 110 nm can be subjected to low-temperature heat treatment in order to improve the reactivity with FEPM on the surface. The low temperature heat treatment will be described later.

The average diameter of carbon nanofibers can be measured by observation with an electron microscope. In the detailed description of the present invention, the average diameter and the average length of the carbon nanofibers are, for example, 5,000 times or more from an electron microscope (the magnification can be appropriately changed depending on the size of the carbon nanofibers), and the diameters of 200 or more locations. And the length can be measured and calculated as the arithmetic average value.

Carbon nanofibers can be blended in an amount of 5 to 30 parts by mass with respect to 100 parts by mass of FEPM. In particular, when carbon nanofibers having an average diameter of 10 nm to 20 nm are used, 5 to 30 parts by mass can be blended with 100 parts by mass of FEPM, and carbon nanofibers having an average diameter of 60 to 110 nm. When a fiber is used, 10 to 30 parts by mass can be blended with 100 parts by mass of FEPM. Carbon nanofibers, particularly when carbon nanofibers with an average diameter of 10 nm to 20 nm are used, are 5 parts by mass or more, and when carbon nanofibers with an average diameter of 60 nm to 110 nm are used, 10 parts by mass or more are transferred to FEPM. Since it is considered that a nano-sized cell structure can be formed by blending, there is a tendency that the wear resistance is improved, and if the blending amount is 30 parts by mass or less, the elongation at break (EB) is Since it is relatively high, it tends to be easy to mount a seal member on a part based on excellent workability. Moreover, the compounding quantity of carbon nanofiber can be reduced by mix | blending fillers other than carbon nanofiber. When the filler is blended, the carbon nanofiber having an average diameter of 10 nm to 20 nm can be blended in an amount of 0.5 to 30 parts by mass with respect to 100 parts by mass of FEPM, and the average diameter is 60 nm to The carbon nanofibers of 110 nm can be blended in an amount of 4 to 30 parts by mass with respect to 100 parts by mass of FEPM. Here, “parts by mass” indicates “phr” unless otherwise specified, and “phr” is an abbreviation for “parts per hundred of resin or rubber” and represents the percentage of external additives such as additives to rubber and the like. It is.

The carbon nanofiber may be a relatively rigid fiber having an average stiffness value of 3 to 12 before being blended with the tetrafluoroethylene-propylene copolymer (FEPM). Particularly, carbon nanofibers having an average diameter of 10 nm to 20 nm can have an average value of stiffness of 3 to 5, and carbon nanofibers having an average diameter of 60 nm to 110 nm have an average value of stiffness of 9 to Can be twelve. Stiffness refers to the rigidity of carbon nanofibers, and is obtained by measuring and calculating the length and diameter of almost unbent portions of many carbon nanofibers taken with a microscope. Sometimes referred to as the bending index. The bent portion of the carbon nanofiber is a defect of the fiber, and appears as a white line crossing the fiber in the width direction with an electron microscope. When the length of the substantially straight portion of the carbon nanofiber that is not bent is Lx and the diameter of the carbon nanofiber is D, the rigidity is defined as Lx ÷ D, and the arithmetic average value is calculated. Therefore, carbon nanofibers with low rigidity are bent at short intervals, and carbon nanofibers with high rigidity are long straight portions and are not bent. The length Lx of the linear portion of the carbon nanofiber is measured in a state where the photographic data of the carbon nanofiber photographed at 10,000 to 50,000 times is enlarged to 2 to 10 times, for example. In the enlarged photograph, a bent portion (defect) that crosses the fiber in the width direction can be confirmed. The distance between adjacent bent portions (defects) thus confirmed is measured by measuring a plurality of, for example, 200 or more locations as the length Lx of the linear portion of the carbon nanofiber.

Carbon nanofibers are so-called multi-walled carbon nanotubes (MWNT: multi-wall carbon nanotubes) having a cylindrical shape formed by winding one surface (graphene sheet) of graphite with a carbon hexagonal mesh surface, and an average diameter of 10 nm to 20 nm. Examples of carbon nanofibers include VGCF-X (VGCF: registered trademark of Showa Denko KK) manufactured by Showa Denko, Baytubes of Bayer MaterialScience, NC-7000 of Nanosyl, and the like. Examples of carbon nanofibers having an average diameter of 60 nm to 110 nm include VGCF-S from Showa Denko. A carbon material partially having a carbon nanotube structure can also be used. In addition to the name “carbon nanotube”, it may be called “graphite fibril nanotube” or “vapor-grown carbon fiber”.

Carbon nanofibers can be obtained by a vapor deposition method. The vapor phase growth method is also called a catalytic chemical vapor deposition (CCVD), in which a gas such as a hydrocarbon is pyrolyzed in the presence of a metal catalyst in the presence of a metal-based catalyst to perform untreated first carbon nano-particles. A method of manufacturing a fiber. The vapor phase growth method will be described in more detail. For example, an organic compound such as benzene or toluene is used as a raw material, an organic transition metal compound such as ferrocene or nickelcene is used as a metal catalyst, and these are used together with a carrier gas at a high temperature such as 400 ° C. It is introduced into a reaction furnace set to a reaction temperature of ~ 1000 ° C, and a floating reaction method (floating reaction method) in which the first carbon nanofibers are generated in a floating state or on the reaction furnace wall, or in advance such as alumina, magnesium oxide, etc. A catalyst-supporting reaction method (substrate reaction method) in which metal-containing particles supported on ceramics are brought into contact with a carbon-containing compound at a high temperature to generate carbon nanofibers on a substrate can be used. Carbon nanofibers having an average diameter of 10 nm to 20 nm can be obtained by a catalyst-supporting reaction method, and carbon nanofibers having an average diameter of 60 nm to 110 nm can be obtained by a floating flow reaction method. The diameter of the carbon nanofiber can be adjusted by, for example, the size of the metal-containing particles and the reaction time. Carbon nanofibers having an average diameter of 10 nm to 20 nm can have a nitrogen adsorption specific surface area of 10 m ² / g to 500 m ² / g, and more preferably 100 m ² / g to 350 m ² / g, It can be 150 m ² / g to 300 m ² / g.

Carbon nanofibers having an average diameter of 60 nm to 110 nm and low-temperature heat treatment can be obtained by low-temperature heat treatment of so-called untreated carbon nanofibers obtained by vapor phase growth. In this low-temperature heat treatment, untreated carbon nanofibers can be heat-treated at a temperature higher than the reaction temperature in the vapor phase growth method at 1100 ° C. to 1600 ° C. The temperature of this heat treatment can be further 1200 ° C. to 1500 ° C., in particular 1400 ° C. to 1500 ° C. When the temperature of the low-temperature heat treatment is higher than the reaction temperature of the vapor phase growth method, the surface structure of the carbon nanofibers can be adjusted and surface defects can be reduced. Further, by setting the low-temperature heat treatment temperature to 1100 ° C. to 1600 ° C., the surface reactivity with FEPM is improved, and the dispersion of carbon nanofibers in the matrix material can be further improved. Thus the carbon nanofibers low-temperature heat treatment, for example, the ratio of the peak intensity D of around 1300 cm ^-1 to the peak intensity G of around 1600 cm ^-1 measured by Raman scattering spectroscopy (D / G) is 0.9 More than 1.0 and less than 1.6, and further 1.0 to 1.4, particularly 1.0 to 1.2 when the temperature of the heat treatment is 1400 ° C. to 1500 ° C. it can. In the Raman spectrum of the carbon nanofibers low-temperature heat treatment, the absorption peak intensity D of around 1300 cm ^-1 is the absorption based on defects in the crystal that forms the carbon nanofibers, the absorption peak intensity G of around 1600 cm ^-1 is carbon nanofiber Absorption based on crystals that form For this reason, the smaller the ratio (D / G) between the peak intensity D and the peak intensity G, the higher the degree of crystallization of the carbon nanofibers. Therefore, the smaller the ratio of the peak intensity D to the peak intensity G (D / G), the higher the degree of graphitization (graphitization), and the carbon nanofibers with fewer defects on the surface. Accordingly, the carbon nanofibers subjected to low-temperature heat treatment having a ratio (D / G) of the peak intensity D to the peak intensity G within the above range have a non-crystalline portion on the surface, and thus have good wettability with FEPM. Since the carbon nanofibers subjected to low-temperature heat treatment have relatively few defects, the strength of the carbon nanofibers can be sufficient.

Usually, carbon nanofibers manufactured by vapor phase growth are heat treated at 2000 ° C. to 3200 ° C. in an inert gas atmosphere to perform so-called graphitization (crystallization) treatment. Impurities such as amorphous deposits and remaining catalytic metals deposited on the surface are removed. The graphitized carbon nanofiber has a relatively low reactivity with FEPM on the surface thereof. Carbon nanofibers having an average diameter of 10 nm to 20 nm and carbon nanofibers having an average diameter of 60 nm to 110 nm and subjected to low-temperature heat treatment can be used as they are without performing such graphitization treatment. As described above, the surface of the carbon nanofiber not subjected to the graphitization treatment has a moderately non-crystalline portion, so that the wettability with FEPM tends to be good.

FIG. 1 is a perspective view schematically showing a compression process of carbon nanofibers used for a seal member according to an embodiment of the present invention. The carbon nanofiber can be further compressed. The carbon nanofibers can be granulated by the compression treatment. Further, the carbon nanofibers produced by the vapor phase growth method include carbon nanofibers having branched portions as they are, and the compression treatment can be performed at a high pressure for cutting the carbon nanofibers at least from the branched portions. . In the compression treatment, carbon nanofibers 60 that are raw materials are inserted between a plurality of, for example, at least two

rolls

72 and 74 that continuously rotate in the direction of the arrow in the figure, and shearing force and compression force are applied to the carbon nanofibers. For example, a dry compression granulator 70 such as a roll press machine or a roller compactor (roll type high pressure compression molding machine) can be employed. By putting a plurality of carbon nanofibers 60 manufactured by the vapor phase growth method into a dry compression granulator 70 and compressing them, an aggregate of a plurality of carbon nanofibers 80 subjected to the compression process can be obtained. The roll press machine normally uses a smooth roll in which pockets are not engraved on the outer peripheral surface of the roll or a roll in which pockets are engraved. In this embodiment, a smooth roll is used in order to apply a compressive force evenly to the carbon nanofibers. be able to. The distance between the two rolls is set to 0 mm, that is, the rolls are in contact with each other, and a predetermined compression force F, for example, 980 to 2940 N / cm can be applied between the two rolls, and further 1500 to 2500 N / Cm is preferred. The compressive force F can be set to an appropriate pressure while confirming the presence or absence of a branched portion in the obtained carbon nanofiber assembly 80 with an electron microscope or the like. If it is 980 N / cm or more, the carbon nanofiber which has a branch part can be cut | disconnected by a branch part. Such compression treatment can be performed a plurality of times, for example, about twice in order to homogenize the entire carbon nanofiber. In a granulator, generally a binder such as water is often blended to bind powder, but the compression treatment in the present embodiment is a dry granulation that does not use a binder for binding carbon nanofibers to each other. Can be. This is because if a binder is used, it may be difficult to disperse the carbon nanofibers in a later step, and a step of removing the binder may be further required. In addition, after compressing between two rolls by the dry compression granulator 70 and forming into an aggregate of plate-like (flakes) carbon nanofibers 80, it is further crushed by a pulverizer or the like and adjusted to a desired size. An aggregate of the granulated carbon nanofibers 80 can be produced. The pulverizer at this time, for example, rotates the rotary blade at high speed and crushes the aggregate of carbon nanofibers 80 by the shearing force, and uses a screen to adjust the size only through the aggregate of carbon nanofibers 80 having an appropriate size or less. It can be performed. The size of the aggregates of the carbon nanofibers 80 varies greatly only by the compression treatment, but the particle size of the aggregates of the carbon nanofibers 80 is adjusted to an appropriate size by further crushing in this way, so that the matrix material It is possible to prevent the carbon nanofiber aggregates from being biased when kneaded. By this compression treatment, the carbon nanofibers are cut at the branching portions, and the desired bulk density that does not become soft becomes easy to handle during processing. For example, the carbon nanofibers can be granulated into a plate-like carbon nanofiber aggregate. .

(II) Tetrafluoroethylene-propylene copolymer The tetrafluoroethylene-propylene copolymer is a binary copolymer mainly composed of tetrafluoroethylene and propylene. For example, the product name Aflas manufactured by Asahi Glass Co., Ltd. can be mentioned. In the following description, tetrafluoroethylene-propylene copolymer is abbreviated as FEPM. FEPM is slightly inferior in wear resistance to hydrogenated acrylonitrile-butadiene rubber (HNBR), but is excellent in high temperature characteristics. For example, in an environment of 175 ° C. or more, which deteriorates with a seal material for a logging device, particularly HNBR. It can be used as a seal member. FEPM can be used in a high temperature environment of 175 ° C. to 200 ° C. In addition, FEPM is superior in chemical resistance compared to FKM, and therefore can be used in an environment where chemical resistance that cannot be used in FKM is required. The FEPM used in this embodiment can have a fluorine content of 50 to 60 mass%, a Mooney viscosity (ML _{1 + 4} 100 ° C.) of 90 to 160, and a glass transition point of 0 ° C. or less. When the fluorine content is 50% by mass or more, the heat resistance is excellent, and when the fluorine content is 60% by mass or less, the chemical resistance such as alkali resistance, acid resistance, and chlorine resistance is excellent. Further, when the median value of Mooney viscosity (ML _{1 + 4} 100 ° C.) is 90 or more, basic required performances such as tensile strength (TB) and compression set (CS) can be obtained, and Mooney viscosity (ML _{1 + 4} 100 ° C.). If the center value of) is 160 or less, it has an appropriate viscosity and can be processed. For example, exploration of underground resources may be conducted under the seabed, but the seabed has a high pressure of about 4 ° C due to its high pressure. If the glass transition point of FEPM is 0 ° C or less, the seal member from the seabed to the hot exploration zone Can be used as

(III) Filler The filler has an average particle size of 5 nm to 300 nm. As the filler, at least one of carbon black, silica, clay, talc and the like that can be used as an elastomer filler can be selected. Carbon black may have an average particle size of 10 nm to 300 nm. Silica, talc and clay may have an average particle size of 5 nm to 50 nm. The filler in this embodiment does not contain carbon nanofibers.

By blending the filler into the FEPM, the matrix region of the FEPM can be divided into minute sizes by the filler, and the matrix region divided into the minute sizes may be reinforced with carbon nanofibers. The compounding quantity of carbon nanofiber can be decreased by mix | blending.

Further, the aspect ratio of the filler is about 10 times or more that of the carbon nanofibers, and the compounding amount of the carbon nanofibers is, for example, 4.5 parts by mass to 5 parts by mixing 50 parts by mass of the filler from the experimental results. Can be reduced.

The sealing member can contain 0.5 to 30 parts by mass of carbon nanofibers with respect to 100 parts by mass of FEPM. However, depending on the type of carbon nanofibers or the presence or absence of fillers, The amount can be changed as appropriate.

When carbon nanofibers having an average diameter of 10 nm to 20 nm are used, 0.5 parts by mass to 30 parts by mass of carbon nanofibers and 0 part by mass to 50 parts by weight of filler having an average particle diameter of 5 nm to 300 nm with respect to 100 parts by mass of FEPM. A mass part. At this time, the compounding amount of the carbon nanofiber and the filler in the sealing member is expressed by the formula (1) when the compounding amount (part by mass) of the filler is W1 and the compounding amount (mass part) of the carbon nanofiber is W2. ): Wt = 0.09W1 + W2 and formula (2): 5 ≦ Wt ≦ 30 can be satisfied. Therefore, when the filler is not included, carbon nanofibers having an average diameter of 10 nm to 20 nm can be included at least 5 parts by mass. When the carbon nanofiber is 0.5 parts by mass, the filler is 50 parts by mass. Can be included.

When carbon nanofibers having an average diameter of 60 nm to 110 nm are used, 4 parts by mass to 30 parts by mass of carbon nanofibers and 0 part by mass to 60 parts by mass of filler having an average particle diameter of 5 nm to 300 nm with respect to 100 parts by mass of FEPM. A mass part. At this time, the compounding amount of the carbon nanofiber and the filler in the sealing member is expressed by the formula (3) when the compounding amount (part by mass) of the filler is W1 and the compounding amount (mass part) of the carbon nanofiber is W2. ): Wt = 0.1W1 + W2 and formula (4): 10 ≦ Wt ≦ 30 can be satisfied. Therefore, when the filler is not included, carbon nanofibers having an average diameter of 60 nm to 110 nm can be included at least 10 parts by mass. When the carbon nanofiber is 4 parts by mass, 60 parts by mass of filler is included. Can do.

(IV) Method for Producing Seal Member A method for producing a seal member according to an embodiment of the present invention is obtained by mixing carbon nanofibers with FEPM and uniformly dispersing the carbon nanofibers in the FEPM with a shearing force. Obtaining a composite material. The seal member can be obtained by molding a carbon fiber composite material into a desired shape. In this step, as the carbon nanofiber, a carbon nanofiber aggregate obtained by compression treatment can be used. This process will be described in detail with reference to FIGS.

2 to 4 are views schematically showing a method for manufacturing a seal member by an open roll method according to an embodiment of the present invention.
As shown in FIGS. 2 to 4, the first roll 10 and the second roll 20 in the two-roll open roll 2 are arranged at a predetermined distance d, for example, 0.5 mm to 1.5 mm. 2 to 4, it rotates in the direction indicated by the arrow at the rotational speeds V1 and V2 by forward rotation or reverse rotation. First, as shown in FIG. 2, the FEPM 30 wound around the first roll 10 is masticated, and the FEPM molecular chain is appropriately cut to generate free radicals. The free radicals of FEPM generated by mastication are likely to be combined with carbon nanofibers.

Next, as shown in FIG. 3, the carbon nanofibers 80 and a filler (not shown) as necessary are put into the bank 34 of the FEPM 30 wound around the first roll 10 and kneaded. The temperature of the FEPM 30 in this kneading can be, for example, 100 ° C. to 200 ° C., and further can be 150 ° C. to 200 ° C. Thus, it is considered that the FEPM is likely to enter the gap between the carbon nanofibers 80 by kneading the FEPM 30 and the carbon nanofibers 80 at a relatively high temperature as compared with the thin type. The step of mixing FEPM 30 and carbon nanofiber 80 is not limited to the open roll method, and for example, a closed kneading method or a multi-screw extrusion kneading method can be used.

Furthermore, as shown in FIG. 4, the roll interval d between the first roll 10 and the second roll 20 is set to, for example, 0.5 mm or less, more preferably 0 to 0.5 mm, and the mixture 36 is Insert into the open roll 2 and perform thinning once to several times. For example, the thinning can be performed about 1 to 10 times. When the surface speed of the first roll 10 is V1 and the surface speed of the second roll 20 is V2, the ratio of the surface speeds (V1 / V2) in thinness is 1.05 to 3.00. Further, it is preferably 1.05 to 1.2. By using such a surface velocity ratio, a desired shear force can be obtained. The carbon fiber composite material 50 extruded from between the narrow rolls as described above is greatly deformed as shown in FIG. 4 due to the restoring force due to the elasticity of the FEPM 30, and the carbon nanofibers 80 move together with the FEPM 30 at that time. The carbon fiber composite material 50 obtained through thinning is rolled with a roll and dispensed into a sheet having a predetermined thickness. In this thinning process, in order to obtain as high a shearing force as possible, the roll temperature is set to a relatively low temperature of, for example, 0 to 50 ° C., more preferably 5 to 30 ° C., and the measured temperature of the FEPM 30 is also 0. Can be adjusted to ~ 50 ° C. Due to the shearing force thus obtained, a high shearing force acts on the FEPM 30, and the aggregated carbon nanofibers 80 are separated from each other so as to be pulled out one by one to the FEPM molecule and dispersed in the FEPM 30. . In particular, since the FEPM 30 has elasticity, viscosity, and chemical interaction with the carbon nanofibers 80, the carbon nanofibers 80 can be easily dispersed. And the carbon fiber composite material 50 excellent in the dispersibility and dispersion stability of carbon nanofiber 80 (it is hard to re-aggregate carbon nanofiber) can be obtained.

More specifically, when FEPM and carbon nanofibers are mixed with an open roll, viscous FEPMs penetrate into each other of carbon nanofibers, and specific parts of FEPM are chemically interacted with carbon nanofibers. Binds to highly active moieties. For example, when the surface of the carbon nanofiber is not graphitized or has a moderately high activity by low-temperature heat treatment or the like, it is particularly easy to bind to the FEPM molecule. Next, when a strong shearing force acts on FEPM, the carbon nanofibers move with the movement of FEPM molecules, and the aggregated carbon nanofibers are separated by the restoring force of FEPM due to elasticity after shearing, Will be dispersed in the FEPM. According to the present embodiment, when the carbon fiber composite material is extruded from between narrow rolls, the carbon fiber composite material is deformed thicker than the roll interval by the restoring force due to the elasticity of FEPM. The deformation can be presumed to cause the carbon fiber composite material subjected to a strong shear force to flow more complicatedly and disperse the carbon nanofibers in the FEPM. And once disperse | distributed carbon nanofiber is prevented from reaggregating by the chemical interaction with FEPM, and can have favorable dispersion stability.

The step of dispersing carbon nanofibers in FEPM by shearing force is not limited to the open roll method, and a closed kneading method or a multi-screw extrusion kneading method can also be used. In short, in this step, it is sufficient that a shearing force capable of separating the aggregated carbon nanofibers can be applied to the FEPM. In particular, the open roll method is preferable because it can measure and manage not only the roll temperature but also the actual temperature of the mixture. A cross-linking agent can be mixed with the dispensed carbon fiber composite material before mixing, mixing, or after passing through the FEPM and carbon nanotubes, and the cross-linked carbon fiber composite material can be crosslinked. it can.

The seal member is molded into a desired shape, for example, endless by a rubber molding process, such as an injection molding method, a transfer molding method, a press molding method, an extrusion molding method, or a calendering method, in which a carbon fiber composite material is generally employed. Can be obtained at The seal member can be made of a crosslinked carbon fiber composite material.

In the method for producing a carbon fiber composite material according to the present embodiment, a compounding agent usually used in FEPM processing can be added. A well-known thing can be used as a compounding agent. Examples of the compounding agent include a crosslinking agent, a vulcanizing agent, a vulcanization accelerator, a vulcanization retarder, a softening agent, a plasticizer, a curing agent, a reinforcing agent, a filler, an antiaging agent, and a coloring agent. it can. These compounding agents can be added to the FEPM at an appropriate time during the mixing process. For example, peroxide can be used as the cross-linking agent. For example, before mixing the carbon nanofibers into the FEPM, together with the carbon nanofibers, or after mixing the carbon nanofibers and the FEPM, it can be added, for example, to prevent scorch. For this purpose, the crosslinking agent can be blended into the uncrosslinked carbon fiber composite material after passing through.

(V) Seal member The seal member can be excellent in physical properties at high temperatures and excellent in wear resistance by reinforcing FEPM with carbon nanofibers. Therefore, the seal member can be used as both a static seal member and a dynamic seal member, but can be used particularly as a dynamic seal member. The sealing member may have a known form, for example, may be endless, a so-called O-ring, a square seal having a rectangular cross-sectional shape, a so-called D-ring having a D-shaped cross-section, and a cross-sectional shape X So-called X-rings, so-called E-rings with a cross-sectional shape of E, so-called V-rings with a cross-sectional shape of V-shaped, U-rings with a cross-sectional shape of U-shape, L-rings with a cross-sectional shape of L-shape Can be adopted. The seal member may be a stator or a rotor of a fluid drive motor such as a mud motor.

FIG. 5 is a diagram schematically showing a tensile fatigue test of the seal member according to the embodiment of the present invention.
As shown in FIG. 5, the tensile fatigue test of the seal member in the present embodiment is a strip-shaped test of the cross-linked carbon fiber composite material manufactured in (IV) 10 mm long × 4 mm wide × 1 mm thick. Cut into a piece 100, insert a notch 106 having a depth of 1 mm in the width direction from the center of the long side 102 of the test piece 100, and hold the vicinity of the

short sides

104, 104 at both ends of the test piece 100 with

chucks

110, 110. In the air atmosphere, a tensile load (0 N / mm to 2 N / mm) is repeatedly applied in the direction of the arrow T in FIG. 5 under the condition of a frequency of 1 Hz, and it can be broken or the number of repetitions up to 1 million can be measured. The cut 106 of the test piece 100 can be formed by cutting to a depth of 1 mm with a razor blade. Although several measurement methods have been proposed so far for the abrasion resistance test of the rubber composition, it is considered that the abrasion resistance can be evaluated by such a tensile fatigue test. The phenomenon that the rubber composition wears due to friction is considered to occur as the rubber composition is torn on the contacted surface. Therefore, the test piece is notched 106 and a tensile fatigue test is performed. If the number is large, it can be estimated that the wear resistance of the seal member is good. The seal member contains carbon nanofibers with respect to tetrafluoroethylene-propylene copolymer (FEPM), and the number of breaks in a tensile fatigue test at 150 ° C., a maximum tensile stress of 2 N / mm, and a frequency of 1 Hz is 10 times or more. Further, the sealing member may have a number of breaks of 30 or more in a tensile fatigue test at 150 ° C., a maximum tensile stress of 2 N / mm, and a frequency of 1 Hz.

Further, it can be estimated that the wear resistance of the seal member is affected by the thickness of the carbon nanofiber, the wettability of the surface, or the presence or absence of a filler. The sealing member is filled with 0.5 to 30 parts by mass of carbon nanofibers having an average diameter of 10 nm to 20 nm and an average particle diameter of 5 to 300 nm with respect to 100 parts by mass of tetrafluoroethylene-propylene copolymer (FEPM). The compounding amount of the carbon nanofiber and the filler can satisfy the following formulas (1) and (2). Furthermore, the compounding amount of the carbon nanofibers having an average diameter of 10 nm to 20 nm can be 1 part by mass to 30 parts by mass, and particularly 5 parts by mass to 30 parts by mass.
Wt = 0.09W1 + W2 (1)
5 ≦ Wt ≦ 30 (2)
W1: Blending amount of filler (parts by mass)
W2: Compounding amount (parts by mass) of carbon nanofibers.

The seal member is composed of 4 parts by mass to 30 parts by mass of carbon nanofibers having an average diameter of 60 nm to 110 nm and 100 parts by mass of tetrafluoroethylene-propylene copolymer (FEPM), and filler 0 having an average particle diameter of 5 nm to 300 nm. The compounding amount of the carbon nanofibers and the filler can satisfy the following formulas (3) and (4). Further, when carbon nanofibers having an average diameter of 60 nm to 110 nm are carbon nanofibers subjected to low-temperature heat treatment, the blending amount of carbon nanofibers can be further 5 to 30 parts by mass, particularly 10 parts by mass to It can be 30 parts by mass.
Wt = 0.1W1 + W2 (3)
10 ≦ Wt ≦ 30 (4)
W1: Blending amount of filler (parts by mass)
W2: Compounding amount (parts by mass) of carbon nanofibers.

When the sealing member is a carbon nanofiber having an average diameter of 10 nm to 20 nm, the compression set after 70% compression at 25 ° C. and 200 hours can be 0% to 90%, and further 30% to 85%. %. When the carbon nanofibers having a mean diameter of 60 nm to 110 nm are heat-treated at a low temperature, the sealing member has a compression set of 0% to 40% after being compressed by 25% and after 70 hours at 200 ° C. Furthermore, it can be 20% to 40%, in particular 30% to 40%. The compression set at this time is measured under the above conditions based on JIS-K6262. The specimen can have a diameter of 29.0 ± 0.5 mm and a thickness of 12.5 ± 0.5 mm. Seal members containing carbon nanofibers having an average diameter of 60 nm to 110 nm tend to be strong against static sag.

FIG. 6 is a diagram schematically showing a wear test of the seal member according to the embodiment of the present invention.
As shown in FIG. 6, the high-pressure wear test of the seal member is performed using a DIN wear tester 120, and the crosslinked carbon fiber composite material sample produced in the above (IV) is cut into a disk-shaped test piece 126 and weighted. 129 can be pressed against the surface of the disk-shaped grindstone 128 that rotates the test piece 126 with a predetermined load to be worn. The test piece 126 is disposed in the water 124 of the water tank 122, and the temperature rise of the test piece 126 due to frictional heat can be suppressed. The disk-shaped test piece 126 can have a diameter of 8 mm and a thickness of 6 mm, and the weight 129 can press the test piece 126 against the disk-shaped grindstone 128 with a load of 49.0 N using, for example, 5 kgf. The surface of the water can have a roughness of # 100, the water 124 in the water tank 122 can be set to room temperature to 80 ° C., and the distance that the test piece 126 and the disc-shaped grindstone 128 rub can be 20 m. Otherwise, the mass (g) of the test piece before and after the abrasion test can be measured in the same manner as the DIN-53516 abrasion test.

The seal member has a wear amount Wa of 0.010 cm ³ / N · m to 0.070 cm ³ / N · m in a high-pressure wear test at 25 ° C., and the wear amount Wa can satisfy the following formula (5). . Further, the seal member, the wear amount Wa is able is ^{0.020cm 3 / N · m ~ 0.065cm} 3 / N · m, in particular ^{0.020cm 3 / N · m ~ 0.060cm} 3 / N · m.
Wa = (g ₂ −g ₁ ) / (P · L · d) (5)
g ₁ : Mass of the test piece before wear (g)
g ₂ : Mass of the test piece after wear (g)
P: Set weight of weight (N)
L: Wear distance (m)
d: Specific gravity (g / cm ³ ).

The carbon fiber composite material for molding the seal member includes FEPM and carbon nanofibers produced by a vapor growth method uniformly dispersed in the FEPM. The uncrosslinked carbon fiber composite material has a characteristic relaxation time (T2′HE / 150 ° C.) of 500 to 1500 μsec, measured at 150 ° C. by the Hahn echo method using pulsed NMR and at ¹ H of the observation nucleus. Furthermore, it can be 500 to 1400 μsec, and particularly 500 to 1300 μsec. Note that “HE” in the characteristic relaxation time (T2′HE) is a notation used to distinguish from “SE” in the solid echo method described later. The characteristic relaxation time (T2′HE) by the Hahn-echo method is a scale indicating the molecular mobility of FEPM and represents the average relaxation time of a multicomponent system. Therefore, the characteristic relaxation time (T2′HE) is an average value of a plurality of relaxation times detected by the Hahn-echo method, and is expressed as “1 / T2′HE = fa / T2a + fb / T2b + fc / T2c. Can do. It can be said that the carbon fiber composite material in which carbon nanofibers are dispersed represents the force that the carbon nanofibers bind to the matrix FEPM molecules, and (T2'HE / 150 ° C) is a blending amount of carbon nanofibers compared to the FEPM alone. It becomes small according to. Therefore, even in the case of a carbon fiber composite material in which carbon nanofibers are mixed, if the carbon nanofibers are not uniformly dispersed, it is difficult to constrain the FEPM molecules as a whole. It is considered that (T2′HE / 150 ° C.) is not significantly different from that of FEPM alone.

The uncrosslinked carbon fiber composite material has a characteristic relaxation time (T2′SE / 150 ° C.) of 0 to 1000 μsec, measured at 150 ° C. by a solid echo method using pulsed NMR and at an observation nucleus of ¹ H. Furthermore, the characteristic relaxation time (T2′SE / 150 ° C.) can be 0 to 800 μsec, and the characteristic relaxation time (T2′SE / 150 ° C.) can be 5 to 500 μsec. The characteristic relaxation time (T2′SE) by the solid echo method is a measure showing the non-uniformity of the magnetic field due to the carbon nanofibers, and represents the average relaxation time of a multicomponent system. Therefore, the characteristic relaxation time (T2′SE) is an average value of a plurality of relaxation times detected by the Hahn echo method, and is expressed as “1 / T2′SE = fa / T2a + fb / T2b + fc / T2c. Can do. Carbon fiber composite material in which carbon nanofibers are dispersed causes magnetic field inhomogeneity due to the uniform dispersion of carbon nanofibers, and the characteristic relaxation time (T2'SE / 150 ° C) by solid echo method at 150 ° C is FEPM. It becomes smaller according to the compounding quantity of carbon nanofiber than a simple substance. In addition, even when carbon nanofibers are mixed with carbon nanofibers, non-uniformity of the magnetic field is not introduced when carbon nanofibers are not uniformly dispersed. It is considered that the relaxation time (T2′SE / 150 ° C.) is almost the same as that of FEPM alone.

Further, around the carbon nanofibers, a part of FEPM is considered to be an aggregate of FEPM molecules in which molecular chains are broken during kneading, and free radicals generated thereby attack and adsorb the surface of the carbon nanofibers. An interfacial phase is formed. The interfacial phase is considered to be similar to a bound rubber formed around carbon black when, for example, an elastomer and carbon black are kneaded. Such an interfacial phase is coated and protected with carbon nanofibers, and FEPM divided into nanometer sizes surrounded by an interfacial phase in which the interfacial phases are chained by blending a predetermined amount or more of carbon nanofibers. Are estimated to form small cells. By forming such small cells almost uniformly throughout the carbon fiber composite material, it is possible to expect an effect that exceeds the effect of simply combining the two materials.

Furthermore, according to one Embodiment of this invention, a sealing material can be used for the oil field use with which severe conditions were equipped. As described above, this sealant not only has high mechanical properties at a high temperature of 175 ° C. or higher, but also maintains high mechanical properties even at a relatively low temperature of 25 ° C. or lower and a high pressure of 5000 psi or higher, or This is because it has high wear resistance, low friction, high gas resistance against H ₂ S, CH ₄ or CO ₂ , high chemical resistance, or high thermal conductivity. The oil field application will be described in detail below.

(VI) Oil field use The seal member for oil field use can be used for an oil field apparatus (Oilfield Apparatus), for example. The seal member of the oil field device can be used for a static seal member and a dynamic seal member. For example, when used for a logging machine, a rotary machine such as a motor, or a reciprocating machine such as a piston. A high effect can be obtained in the dynamic seal member. A typical embodiment of the oil field apparatus will be described below.

For example, the logging equipment is used for physical properties such as formations and oil reservoirs in and around excavated boreholes, geometric properties of wells or casings (bore diameter, orientation, slope, etc.), flow of oil reservoirs, etc. Is a device for recording the behavior of each at every depth, and can be used, for example, in an oil field. Examples of the logging device for oil field use include the subsea use shown in FIG. 7 and the underground use shown in FIG. The logging equipment includes wireline logging (Wireline logging / logging), mud logging (Mud logging), etc., and logging logging (LWD: Logging Willing Drilling) where measuring equipment is equipped in the drilling assembly. There are measurements during excavation (MWD: Measurement While Drilling). Since these logging devices work at a deep depth in the ground, the surrounding environment becomes severe for the seal member, and it is necessary to withstand friction and maintain a liquid-tight state in a state exposed to high temperature, particularly 175 ° C. or more. In some cases, heat resistance higher than that of the HNBR composite material may be required.

7 to 10, the seal member according to an embodiment of the present invention used in the logging apparatus will be described. FIG. 7 is a cross-sectional view schematically showing a logging tool for seabed use according to an embodiment of the present invention. FIG. 8 is a partial cross-sectional view schematically showing the logging apparatus of FIG. 7 according to one embodiment of the present invention. FIG. 9 is an X-X ′ cross-sectional view schematically showing a mud motor of the logging apparatus of FIG. 8. FIG. 10 is a cross-sectional view schematically showing an underground logging tool according to an embodiment of the present invention.

As shown in FIG. 7, the exploration of underground resources by the measuring equipment installed in the drilling assembly in the ocean is, for example, a well 156 composed of a vertical hole or a horizontal hole provided in the seabed 154 from the platform 150 floating in the sea 152. For example, a bottom hole assembly (BHA) 160 is entered as a logging device, and the underground geological structure and the like are searched for, for example, the presence or absence of petroleum as a target material. The hole bottom assembly 160 is fixed to the tip of a long drill string 153 extending from the platform 150, for example, and has a plurality of modules. For example, in order from the tip, a drill bit 162, a rotary operation system (RSS: A rotary steerable system 164, a mud motor 166, a measurement module 168 during excavation, and a logging module 170 during excavation may be connected. The drill bit 162 can advance excavation by rotation at the bottom portion 156 a of the well 156.

8 is a system that has a deflection mechanism (not shown) that deflects the bit in a certain direction while rotating the drill bit 162, and enables tilt-controlled excavation. The rotation operation system 164 can apply the seal member of one embodiment of the present invention. The rotary operation system 164 requires a seal member having high wear resistance at, for example, a maximum of about 210 ° C., and a seal member having high chemical resistance against exposure to various muddy water. Conventional seal members tend to fail due to rubber wear and tear. In particular, in harsh chemical environments, the problem tended to be serious. Sealing members for rotary steerable systems such as those shown in US 2006/0157283 are required to function at high sliding speeds (~ 100 mm / sec) The above problems of seal members tended to be exacerbated by the degradation of elastomeric properties at temperature and the wear characteristics of drilling fluids. In contrast, by using the seal member of one embodiment of the present invention for the seal member of the rotary operation system 164, in addition to the above-described characteristics of the seal member, high wear resistance for sealing from a drilling mud containing particles. The above problems can be solved by the performance, the better chemical resistance to a wide range of drilling fluids, and the better mechanical properties at high temperatures that reduce tearing. The rotation operation system 164 includes a non-rotating cylindrical casing 164a, a transmission shaft 164b that passes through the casing 164a and transmits the rotational force of the mud motor 166 to the drill bit 162, and the transmission shaft 164b within the casing 164a. And a seal member 164c that is rotatably supported. The seal member 164c can be, for example, an endless O-ring fitted in an annular groove provided in the housing 164a, and has a function of sealing with the surface of the rotating transmission shaft 164b. Since this seal member 164c is the seal member obtained in (IV) above, it has excellent wear resistance even in a severe underground environment at a high temperature, for example, up to about 200 ° C., so that the sealing function can be maintained for a long time. it can. The use of such seal members is found, for example, in US Patent Application Publication No. 2006/0157283 and US Pat. No. 7,188,685, which are incorporated herein in their entirety. More specifically, FIG. 5 of US 2006/0157283 shows a sealing member 38 on the piston 36 that seals the hole 30 of the biasing device of the rotary variable assembly. U.S. Pat. No. 7,188,685 shows a biasing device.

The mud motor 166 shown in FIG. 9 is also referred to as a downhole motor, and is a fluid drive motor for rotating the drill bit 162 using the fluid force of muddy water as power. For example, the mud motor 166 may be a mud motor for excursion of well-balanced wells (for wellwell drilling applications), and the seal member of one embodiment of the present invention can be applied. The mud motor 166 has, for example, a seal member having a high temperature characteristic of about 150 ° C. to 200 ° C. at maximum, a seal member capable of functioning under extreme wear conditions, or chemical resistance for handling various excavation muds. A sealing member is required. The sealing member of the conventional mud motor is, for example, insufficient sealing due to expansion of the sealing member, cracks and dropping of a large fragment of the sealing member body (chunking phenomenon), insufficient sealing due to wear at high temperature, and sealing due to the wear action of the sealing member. There was a tendency for local heating and further degradation of the members. On the other hand, by using the seal member of one embodiment of the present invention for the seal member of the mud motor 166, in addition to the above-described characteristics of the seal member, tearing and dropping are reduced due to superior mechanical characteristics at high temperatures. The above-mentioned problems can be solved by resistance to a wide range of drilling fluids with excellent chemical resistance and reduction of locally heated portions due to better thermal conductivity. The mud motor 166 has a cylindrical casing 166a, a tubular stator 166 fixed to the inner peripheral surface of the casing 166a, and a rotor 166c rotatably disposed inside the stator 166d. On the inner peripheral surface 166d of the stator 166b, for example, five spiral grooves extend from the rotary operation system 164 side to the measuring module 168 side during excavation. As the stator 166b, the seal member according to the embodiment of the present invention obtained in (IV) can be used. For example, the outer peripheral surface 166e of the metal rotor 166c has, for example, four spirally protruding threads and is disposed along the groove of the inner peripheral surface 166d of the stator 166b. The inner peripheral surface 166d of the stator 166b and the outer peripheral surface 166e of the rotor 166c are partly in contact as shown in FIG. 9, and a flow path for flowing muddy water is formed in the gap 166f between the inner peripheral surface 166d and the outer peripheral surface 166e. . When the muddy water flowing through the gap 166f and the outer peripheral surface 166e of the rotor 166c come into contact with each other, the rotor 166c can eccentrically rotate in the stator 166b, for example, in the direction of the arrows in FIGS. At this time, since the inner peripheral surface 166d of the stator 166b and the outer peripheral surface 166e of the rotor 166c are in contact with each other and rotate eccentrically by muddy water, the inner peripheral surface 166d of the stator 166b functions in the same manner as a so-called seal member. Therefore, since the wear resistance is excellent even in the harsh underground environment as described above, the rotor 166c of the mud motor 166 can be driven to rotate for a long time. In the present embodiment, the mud motor 166 has been described as the fluid drive motor. However, the fluid drive motor can be applied to other fluid drive motors that have the same structure and are driven using a fluid. The rotor may be formed of the seal member obtained in (IV), and the stator may be formed of, for example, metal. Use of such seal members is found, for example, in US Patent Application Publication No. 2006/0216178 and US Patent No. 6,604,922, which are incorporated herein in their entirety. More specifically, FIG. 3 of US Patent Application Publication No. 2006/0216178 shows a sealing member as an elastomeric stator (lining) that seals the rotor and generates drilling torque on the rotor. The mud flows between the stator and the rotor. FIG. 4 also shows a seal member as an elastomer sleeve attached to the rotor, which seals the stator. Similarly, FIG. 5 shows a sealing member as an elastomer sleeve on a rotor that seals the stator. FIG. 4 of US Pat. No. 6,604,922 shows that the elastic layer of the liner attached to the stator has a sealing function, and this elastic layer functions as a sealing member. Similarly, FIG. 13 shows that the rotor lining made of an elastomer layer has a sealing function, and this elastomer layer functions as a sealing member.

In the excavation measurement module 168, a measurement instrument during excavation (not shown) is arranged in a chamber 168a provided on a wall portion of a pipe having a thick wall called a drill collar. The measuring instrument during excavation includes various sensors, for example, measuring bottom hole data such as heading, inclination, bit direction, load, torque, temperature, pressure, etc., and transmitting these measurement data to the ground in real time. Can do.

During the excavation logging module 170, a logging instrument during excavation (not shown) is arranged in a chamber 170a provided on a wall portion of a pipe having a thick wall called a drill collar. The logging tool during excavation includes various sensors, for example, can measure specific resistance, porosity, sonic velocity, gamma ray, etc., and acquire physical logging data. Can be transmitted.

The measurement module 168 during excavation and the logging module 170 during excavation use the seal member of the embodiment of the present invention obtained in (IV) in the chambers 168a and 170a in order to protect various sensors from muddy water. it can.

As shown in FIG. 10, the exploration of underground resources on the ground surface 155 using the measurement equipment installed in the drilling assembly includes, for example, a platform and derrick assembly 151 disposed above a borehole 156, and a derrick assembly. For example, a well bottom assembly (BHA: bottom hole assembly) 160 is provided as a well logging device arranged in a well 156 constituted by vertical holes and horizontal holes provided underground from 151. The derrick assembly 151 can include, for example, a hook 151a, a rotary swivel 151b, a kelly 151c, and a rotary table 151d. The hole bottom assembly 160 is fixed to the tip of a long drill string 153 extending from the derrick assembly 151, for example. Inside the drill string 153, muddy water is fed from a pump (not shown) via the rotary swivel 151b, and the fluid drive motor of the hole bottom assembly 160 can be driven. The hole bottom assembly 160 is basically the same as the logging tool for seabed use described with reference to FIGS. 8 to 10 and therefore will not be described here. The seal member of the embodiment can be employed. In addition, the hole bottom assembly 160 demonstrates the example which has the drill bit 162, the rotation operation system 164, the mud motor 166, the measurement module 168 during excavation, and the logging module 170 during excavation as one Embodiment. However, it is not limited to this, and can be selected and combined according to the logging application.

Oil field use is not limited to the above logging tool. For example, the seal member of one embodiment of the present invention can be applied to a downhole tractor used for wireline logging. An example of such a downhole tractor is Schlumberger MaxTRAC or TuffTRAC (both are trademarks of Schlumberger). Such a downhole tractor requires a reciprocating seal member having high wear resistance at a maximum of about 175 ° C. for long-term operation and reliability.

[To date, the sealing members required a high degree of polishing on the surface of the sealing piston in the downhole tractor. By polishing the seal member in this way, it has led to a high yield of the surface of the piston or cylinder that has been mirror-finished during manufacture. Conventional seal members made of ordinary elastomer have been worn out, leaked, have reduced device life, and have failed. Further, the seal member may be used at a high sliding speed of 2000 ft / hour at the maximum. Sealing members used in downhole tractors function in the presence of hydraulic oil on both sides or in the presence of hydraulic oil on one side and possibly in the presence of mud or fluid containing particles on the other side There is a need. In tractor work, it is necessary that the sliding seal member function sufficiently over a sliding distance larger than the towing distance. For example, in a 10,000 foot tractor operation, the seal member is required to function reliably over a cumulative sliding distance of up to 20,000 feet. In addition, the seal member will typically experience a differential pressure of up to 200 psi.

On the other hand, by using the seal member of one embodiment of the present invention for a downhole tractor, the above-described problems can be solved by the characteristics of the above-described seal member. In particular, the processing on the surface of the sealing piston and the cylinder is eased, and the manufacturing cost can be reduced. Excellent wear resistance also helps with a longer life and reliable sealing function. Further, a long life is possible due to low friction.

The use of such seal members can be found, for example, in US Pat. No. 6,179,055, which is incorporated herein in its entirety. More specifically, FIGS. 9A and 10A of this US patent show a seal member on the piston. The same applies to FIGS. 9B, 10B and 12 of this patent. FIGS. 15, 12, and 16B of this patent show a sealing member on the piston that seals the tubing and housing. FIG. 16B of this US patent also shows a seal member on the rod.

In addition, as an oil field application, for example, the seal member of one embodiment of the present invention can be applied to formation testing and oil reservoir fluid sampling equipment (Formation testing and reservoir fluid sampling tool). Such devices include, for example, Schlumberger's Modular Formation Dynamics Tester (MDT: Trademark of Schlumberger). Such a geological survey and oil reservoir fluid sampling device requires a seal member having high wear resistance in the pump-out module and other pistons. In addition, formation inspection and oil reservoir fluid sampling instruments require seal members with high wear resistance and high temperature properties up to about 210 ° C. to seal wells.

The conventional seal member is a piston of the displacement unit of the pump-out module. A large number of reciprocating motions move, extract, and supply the oil reservoir fluid, and perform sampling, instrument operation, analysis, I was doing. Conventional piston seal members using normal seal members tend to wear out and fail after a limited life. This problem was noticeable at higher temperatures. Also, the presence of particles in the fluid accelerated wear and breakage of the seal member.

On the other hand, the above-mentioned problems can be solved by using the seal member according to the embodiment of the present invention for the geological examination and the oil reservoir fluid sampling device due to the characteristics of the seal member. In particular, a seal member having high wear resistance at high temperatures can improve the life. A seal member having low frictional properties can reduce wear and improve life. In addition, a seal member having high mechanical properties at high temperatures can improve the life and reliability. Furthermore, the sealing member having high chemical resistance can be used for exposure to oil wells and fluids at high temperatures.

Such use of seal members can be found, for example, in US Pat. No. 6,058,773 and US Pat. No. 3,653,436, which are incorporated herein in their entirety. More specifically, FIG. 2 of US Pat. No. 6,058,773 shows a reciprocating seal member on a shuttle piston in a transfer unit (DU) provided in a pump-out module. FIGS. 2, 3, and 4 of US Pat. No. 3,653,436 show an elastomeric member that seals the surface of a well lined with a mud cake.

In addition, as an oil field application, for example, in-situ fluid sampling bottles (In situ fluid sampling bottles) and in-situ fluid analysis / sampling bottles (In situ fluid analysis and sampling bottles) also include the seal member of one embodiment of the present invention. Can be applied. Such equipment can be used, for example, for geological inspection and oil reservoir fluid sampling equipment and wireline logging. Such in-situ fluid sampling bottles and in-situ fluid analysis / sampling bottles require a seal member that allows high pressure use at low and high temperatures. Further, such in-situ fluid sampling bottles and in-situ fluid analysis / sampling bottles require a seal member having high chemical resistance when exposed to various produced fluids. Furthermore, such in-situ fluid sampling bottles and in-situ fluid analysis / sampling bottles require a gas-resistant seal member.

In such in-situ fluid sampling bottles and in-situ fluid analysis / sampling bottles, the oil reservoir fluid has been recovered at the oil reservoir conditions in the field having high pressure and high temperature. When these bottles were recovered to the surface, the pressure remained high although the temperature decreased. After collection, the sample was transferred to another storage, transportation or analysis container. The seal member on the sliding piston in the sample bottle has an important function described below during the collection of the sample, as in the transport of the sample. For example, due to loss of sample in the deep sea area when high-pressure and low-temperature sealing is not possible when recovering to the surface, loss of sample on the surface at the time of recovery, chemical incompatibility with the sample, and poor sealing caused by expansion due to gas absorption Loss of sample, gas-absorbed seal member expands to increase piston friction and drag, excessive expansion of seal member causes poor adherence and seal or other when transferring sample from bottle to other storage location or analyzer And the problem that a plurality of sample bottles are used in piles at the time of work. Loss of sample on the surface at the time of recovery could lead to some problems, especially when the sample contains substances such as H ₂ S, CH ₄ , CO ₂ .

On the other hand, by using the seal member of one embodiment of the present invention for the in-situ fluid sampling bottle and the in-situ fluid analysis / sampling bottle, in addition to the above-described characteristics of the seal member, high gas resistance and high resistance The above problems can be solved by achieving excellent low-temperature sealing performance while satisfying chemical properties and high-pressure and high-temperature required characteristics.

The use of such seal members is described, for example, in US Pat. No. 6,058,773, US Pat. No. 4,860,581, and US Pat. No. 6,467,544, which are incorporated herein in their entirety. (Brown et al.). More specifically, FIG. 7 of US Pat. No. 6,058,773 shows a sealing member on a piston in a sample bottle. The two bottle configuration in FIG. 2 of US Pat. No. 4,860,581 shows a sealing member on a piston in the sample bottle. FIG. 1 of US Pat. No. 6,467,544 shows a seal valve.

Also, as an oil field application, for example, the seal member of one embodiment of the present invention can be applied to in-situ fluid analysis equipment (IFA: In Situ Fluid Analysis tool). Such an in-situ fluid analysis instrument requires a seal member having high wear resistance and gas resistance for downhole PVT. PVT means analyzing pressure, volume, and temperature. Further, the in-situ fluid analyzer requires a seal member having high chemical resistance for handling the produced fluid. Further, the in-situ fluid analysis instrument requires a flow line fixed seal member having high pressure, high temperature characteristics up to about 210 ° C. and high gas resistance. A flow line is an area exposed to sampled fluid.

For example, in the downhole PVT, the in-situ fluid analysis instrument needs to collect the oil reservoir fluid sample, reduce the pressure, start gas generation, and determine the bubble point. The depressurization was very rapid, for example, greater than 3000 psi / min, and an abrupt depressurization could occur in the seal member directly connected to the PVT sample chamber. The seal member had to be able to withstand over 200 PVT cycles. In addition, the seal member for downhole PVT sometimes fails to function due to the gas due to sudden pressure reduction. Therefore, the downhole PVT cannot be performed at 210 ° C. with a conventional commercially available sealing member. In the conventional sealing member, in the flow line, a defect due to expansion and water bubble formation due to gas permeation may occur.

On the other hand, the above-described problems can be solved by using the seal member according to the embodiment of the present invention for the in-situ fluid analysis instrument. A sealing member having excellent mechanical properties at high pressure and high temperature can reduce the expansion tendency. The seal member in which the voids in the seal member are reduced by the carbon nanofiber can improve the gas resistance. By improving the material characteristics of the seal member, it is possible to improve resistance to expansion and sudden pressure reduction. A sealing member having excellent chemical resistance can improve chemical resistance against a wide range of produced fluids.

The use of such seal members can be found, for example, in U.S. Patent Application Publication No. 2009/0078412, U.S. Patent No. 6,758,090, U.S. Pat. No. 4,782,695, incorporated herein in its entirety. And in US Pat. No. 7,461,547. More specifically, FIG. 7 of US 2009/0078412 shows a seal member on a valve and FIG. 5 shows a seal member on a piston seal device. FIG. 21a of US Pat. No. 6,758,090 shows a seal member on the valve and piston. U.S. Pat. No. 4,782,695 shows a seal member between a needle and a PVT processing chamber. U.S. Pat. No. 7,461,547 shows a seal member on a valve for isolating fluid in a PVCU as a seal member of a piston sleeve device in a PVCU (pressure volume control unit) for PVT analysis.

In addition, as an oil field application, for example, the seal member of one embodiment of the present invention is applied to all devices used for wireline logging, logging during drilling, well testing, perforation, and sampling operations. be able to. Such devices require, for example, a sealing member that enables high pressure sealing at low and high temperatures.

For such devices, for example, when used in the deep sea, a seal member that functions in a wide temperature range from low temperature to high temperature is required, and when the seal member does not function normally at low temperatures, Leakage and equipment failure could occur. Further, in sampling in a cold water region such as the deep sea region or the North Sea, the seal member has to function in a wide temperature range from a low temperature to a high temperature. This is because, in such a water area, the sample collected in the ground is hot, but the temperature of the sample carried to the ground surface decreases to the ground surface temperature. For example, when the sealing member is insufficiently sealed at high pressure and low temperature, there is a possibility that sample leakage or loss and other problems may occur. Many of these devices are filled with hydraulic oil and pressurized to 100-200 psi, so if you do not use a seal member that functions well at low temperatures, oil leakage may occur under cold surface conditions, There was a possibility of troubles during recovery from the low temperature deep sea.

On the other hand, by using the sealing member according to an embodiment of the present invention for such a device, in addition to the above-described characteristics of the sealing member, high-temperature high-temperature due to excellent low-temperature sealing properties and superior mechanical characteristics at high temperatures. The above-mentioned problems can be solved by the excellent hermeticity in.

Also, as an oil field application, for example, the seal member of one embodiment of the present invention can be applied to a side wall coring tool. Such side wall coring equipment includes, for example, a seal member having low friction and high wear resistance, a seal member having a long life and high sealing reliability, a seal member having a high temperature characteristic of about 200 ° C. at maximum, or A seal member having a Delta P of 100 psi or less (low speed sliding) is required. Here, Delta P is a pressure difference between both sides of the seal member of the piston. For example, when the seal member has low friction, the Delta P becomes small, that is, the piston can be moved with a small pressure difference.

Such a side wall coring device sometimes stops the coring when, for example, the sealing member causes adhesion or an increase in frictional force. In the drilling of each core, it was required to rotate and slide the drill bit by engaging with the seal member while cutting the formation. Furthermore, in order to maintain high core drilling efficiency, low sealing friction in the seal member was important.

On the other hand, by using the sealing member of one embodiment of the present invention for such a device, the above-described problems can be solved by the following characteristics in addition to the characteristics of the above-described sealing member. A low friction seal member can reduce power consumption for core drilling operations and actuation / movement. In addition, the low friction seal member can reduce the tendency of sticking and rolling and improve the efficiency of core excavation work. Furthermore, the seal member having high wear resistance can improve the sealing life in a fluid having wear properties.

The use of such seal members is described, for example, in US Patent Publication No. 2009/0133932, US Pat. No. 4,714,119, and US Pat. No. 7,191,831, which are incorporated herein in their entirety. It can be seen. More particularly, FIGS. 4 and 5 of US Patent Publication No. 2009/0133932 show a seal member on a coring bit of a coring assembly driven by a motor. FIGS. 3B, 7 and 8 of U.S. Pat. No. 4,714,119 show a seal member on a drill bit that is driven to mine a core from a borehole by a motor at up to 2000 rpm. FIGS. 2A and 2B of U.S. Pat. No. 7,191,831 show a seal member between a coring bit and a coring assembly driven by a motor, and the parts denoted by reference numerals 201 to 204 in FIGS. High efficiency can be achieved by using a low friction seal member such as the seal member of this embodiment between the boundary of FIG.

In addition, as an oil field application, for example, a telemetry / power generation tool for drilling application (Telemetry and power generation tool in Drilling applications) can be applied to the seal member of one embodiment of the present invention. Such telemetry / power generation equipment requires, for example, a rotating seal member having high wear resistance, a rotating / sliding seal member having low friction, and a seal member having a high temperature characteristic of about 175 ° C. at the maximum.

Such a telemetry / power generation device, for example, a mud pulse telemetry device as disclosed in US Pat. No. 7,083,008, uses a well seal fluid ( Protection from drilling mud was required. However, since particles are contained in the well fluid, there is a tendency for wear and tear of the seal member to increase. In addition, due to insufficient sealing due to wear and wear of the seal member, there was a possibility that equipment failure would occur if muddy water entered. Also, the telemetry and power generation device disclosed in US Pat. No. 7,083,008 operates using a sliding seal member on the piston that compensates the internal hydraulic pressure with an external fluid, and wear of the seal member Due to wear, expansion, and sticking, there is a possibility that equipment failure occurs due to intrusion of external fluid.

On the other hand, by using the seal member according to one embodiment of the present invention for telemetry / power generation equipment, in addition to the above-described characteristics of the seal member, the wear resistance and the low friction property of the seal member are improved, thereby improving reliability. The above-mentioned problems can be solved by obtaining a high work and a longer seal life.

The use of such seal members can be found, for example, in US Pat. No. 7,083,008, which is incorporated herein in its entirety. More specifically, FIG. 2 of US Pat. No. 7,083,008 shows a rotary seal member in a rotor-to-rotor seal member / bearing assembly, and FIG. 3a shows oil and well fluid (mud) in a pressure compensation chamber. Fig. 5 shows a sliding seal member on a compensating piston to be separated.

In addition, as an oil field application, for example, the seal member according to an embodiment of the present invention is also applied to an expansion packer used to isolate a part of a well for sampling and geological inspection. Can do. The seal member in such an expansion packer needs to have high wear strength and high temperature characteristics in order to enable repeated operations of expansion and contraction at a plurality of positions in the well.

The seal member in the conventional packer does not have the desired high-temperature characteristics, and thus has a tendency to deteriorate / decrease in the sealing function. Also, the conventional packer sealing members tend not to meet the desired life.

In contrast, by using the seal member of one embodiment of the present invention for an expansion packer, the seal member has better wear resistance and higher high temperature characteristics, thereby improving the life and reliability of the packer member. can do.

The use of such seal members is described, for example, in US Pat. No. 7,578,342, US Pat. No. 4,860,581, and US Pat. No. 7,392,851, which are incorporated herein in their entirety. Seen in More specifically, FIGS. 1A, 1B, and 1C of US Pat. No. 7,578,342 show that the seal member expands to seal the blast hole and isolate the member indicated at 16. ing. Further, the elastomer seal member (packer member) in FIG. 4A or the members denoted by reference numerals 712 and 812 in FIGS. 7 and 8 indicate the seal members. FIG. 1 of US Pat. No. 4,860,581 shows an expansion packer member that seals a well. U.S. Patent No. 7,392,851 shows an expansion packer member.

As described above, the embodiments of the present invention have been described in detail. However, those skilled in the art can easily understand that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention.

Examples of the present invention will be described below, but the present invention is not limited thereto.

(1) Preparation of carbon nanofibers By means of a catalyst reaction method (Substrate Reaction Method), an average diameter of 15 nm, a frequency maximum diameter of 18 nm, a stiffness index of 4.8, a Raman peak ratio (D / G) of 1.7, a nitrogen adsorption specific surface area A 260 m ² / g multilayer carbon nanofiber (shown as “MWCNT-1” in Table 1) was produced. The manufacturing conditions were as follows. By ultrasonication for 20 minutes in a solution obtained by dissolving 10.0 g of aluminum oxide powder, 0.2 g of ammonium iron citrate and 0.1 g of hexaammonium heptamolybdate tetrahydrate in 300 ml of pure water. Dispersed. Next, this solution was dried at 100 ° C. with stirring to obtain catalyst powder. The catalyst powder was placed in an alumina boat and placed in a tubular electric furnace. The reaction tube of the electric furnace was a quartz tube having an inner diameter of 3 cm and a length of 1.5 m, and the length direction in the central part was 600 mm, and a boat in which catalyst powder was put in the central part of the heating area was arranged. After raising the temperature of the electric furnace to 800 ° C. under an argon atmosphere, a mixed gas of ethylene and argon was circulated for 30 minutes to obtain carbon nanotubes having an average diameter of 15 nm. Graphitization of carbon nanofibers is not performed. The carbon nanofiber is a photograph taken with an electron microscope (SEM) at 1.0 kV and 10,000 times to 100,000 times, and is a length of a substantially straight portion where the fiber is not bent. The fiber diameter D is measured, and the result is used to calculate the stiffness index at 200 locations for each fiber type by Lx / D, and the stiffness index is divided by the number of measurement locations (200) to obtain the average stiffness The degree index was determined.

Untreated carbon nanofibers having an average diameter of 87 nm were produced by the floating flow reaction method. The manufacturing conditions were as follows. A spray nozzle is attached to the top of a vertical heating furnace (inner diameter 17.0 cm, length 150 cm). The furnace wall temperature (reaction temperature) is raised to and maintained at 1000 ° C., and 20 g / min of a benzene liquid raw material containing 4% by weight of ferrocene is supplied from the spray nozzle at a flow rate of hydrogen gas of 100 L / min. To be sprayed directly. The shape of the spray at this time is a conical side surface (trumpet shape or umbrella shape), and the apex angle of the nozzle is 60 °. Under these conditions, ferrocene is pyrolyzed to produce iron fine particles, which become seeds, which generate and grow carbon nanofibers from the carbon produced by pyrolysis of benzene, and the carbon nanofibers are spaced every 5 minutes. And continuously produced for 1 hour. Carbon nanofibers obtained by subjecting the untreated carbon nanofibers having an average diameter of 87 nm to low temperature heat treatment at 1500 ° C., which is lower than the reaction temperature in the floating flow reaction method, in an inert gas atmosphere (“MWCNT-2” in Table 1). Obtained). Carbon nanofibers (MWCNT-2) heat-treated at low temperature have an average diameter of 87 nm, a frequency maximum diameter of 90 nm, a stiffness index of 9.9, a surface oxygen concentration of 2.1 atm%, a Raman peak ratio (D / G) of 1.12, The nitrogen adsorption specific surface area was 30 m ² / g.

In addition, the carbon nanofiber (MWNT-2) subjected to low-temperature heat treatment was granulated by roll treatment in order to improve handling properties in the manufacturing process. The roll treatment is a roll press machine that is a dry compression granulator having two rolls of carbon nanofibers (roll diameter is 150 mm, rolls are smooth rolls, roll interval is 0 mm, set compression force between rolls (linear pressure) ) 1960 N / cm, gear ratio 1: 1.3, roll rotation speed 3 rpm) and granulated into a plate-like lump (carbon nanofiber aggregate) having a diameter of about 2 to 3 cm. The particle size was adjusted by crushing through a crushing granulator (rotating speed: 15 rpm, screen: 5 mm) having a rotary blade.

(2) Preparation of carbon fiber composite material samples of Examples 1 to 7 and Comparative Examples 1 to 4 As Examples 1 to 7 and Comparative Examples 2 to 4 samples, FEPM (Table 1, 2) (indicated as “FEPM”) and after mastication, a predetermined amount of carbon nanofibers and carbon black (indicated in “MT-CB” in Tables 1 and 2) shown in Tables 1 and 2 are introduced into FEPM. Then, after kneading at a chamber temperature of 150 ° C. to 200 ° C., the first kneading step was performed and the product was taken out from the roll. Further, the mixture was wound around an open roll (roll temperature: 10 to 20 ° C., roll interval: 0.3 mm), and thinning was repeated 5 times. At this time, the surface speed ratio of the two rolls was set to 1.1. Furthermore, the carbon fiber composite material obtained by setting the roll gap to 1.1 mm and passing through was put and dispensed. The separated sheets were compression molded at 120 ° C. for 2 minutes to obtain uncrosslinked carbon fiber composite material samples of Examples 1 to 7 and Comparative Examples 2 to 4 having a thickness of 1 mm. Further, the carbon fiber composite material obtained by passing through the thin film was mixed with 2 parts by weight of peroxide (indicated as “PO” in Tables 1 and 2) and triallyl isocyanurate (in Tables 1 and 2 as “TAIC”). Sheets added and dispensed were formed by press vulcanization (170 ° C./20 minutes) and secondary vulcanization (200 ° C./4 hours), and Examples 1 to 7 having a thickness of 1 mm and Comparative Example 2 ~ 6 sheet-like crosslinked carbon fiber composite material samples were obtained. In Comparative Example 1, neither carbon nanofiber nor carbon black was blended, but the same kneading process was performed.

In Tables 1 and 2, “FEPM” is a ternary tetramer made by Asahi Glass Co., Ltd. having a fluorine content of 57 mass%, a Mooney viscosity (ML _{1 + 4} 100 ° C.) of 95, and a glass transition point of −3 ° C. It was a fluoroethylene-propylene copolymer (FEPM).
In Tables 1 and 2, “MT-CB” was MT grade carbon black having an arithmetic average diameter of 200 nm.

(3) Measurement Using Pulsed Method NMR Measurement of each uncrosslinked carbon fiber composite material sample of Examples 1 to 7 and Comparative Examples 1 to 4 was performed by Hahn echo method using pulsed method NMR. This measurement was performed using “JMN-MU25” manufactured by JEOL Ltd. The measurement is carried out under the conditions that the observation nucleus is ¹ H, the resonance frequency is 25 MHz, the 90 ° pulse width is 2 μsec, and the decay curve is measured by the pulse sequence of the Hahn-echo method (90 ° x-Pi-180 ° y). The characteristic relaxation time (T2′HE) at 150 ° C. of the carbon fiber composite material sample was measured. The measurement results are shown in Table 1. Moreover, the measurement by the solid echo method was performed using pulse method NMR. This measurement was performed using “JMN-MU25” manufactured by JEOL Ltd. The measurement is performed under the conditions of an observation nucleus of ¹ H, a resonance frequency of 25 MHz, a 90 ° pulse width of 2 μsec, and an attenuation curve is measured by a pulse sequence (90 ° x-Pi-90 ° y) of the solid echo method. The characteristic relaxation time (T2′SE) at 150 ° C. of the carbon fiber composite material sample was detected. The measurement results are shown in Table 1.

(4) Measurement of hardness, 50% modulus, 100% modulus, tensile strength, elongation at break, compression set, tear strength, tear energy, tensile fatigue life and DIN wear Examples 1 to 7 and Comparative Examples 1 to 4 The rubber hardness (Hs (JIS-A)) of the carbon fiber composite material sample of the crosslinked product was measured based on JIS K 6253.

About the test piece which cut the carbon fiber composite material sample of the bridge | crosslinking body of Examples 1-7 and Comparative Examples 1-4 into the dumbbell shape of JIS6 type | mold, it was 23 +/- 2 degreeC using the tensile tester by Toyo Seiki Co., Ltd. Tensile test was performed based on JIS K6251 at a tensile speed of 500 mm / min, tensile strength (indicated as “TB (MPa)” in Tables 1 and 2), and elongation at break (“EB (%) in Tables 1 and 2). ), 50% stress (shown as “M50” in Tables 1 and 2), and 100% stress (shown as “M100” in Tables 1 and 2).

The crosslinked carbon fiber composite material samples of Examples 1 to 7 and Comparative Examples 1 to 4 were cut into test pieces having a diameter of 29.0 ± 0.5 mm and a thickness of 12.5 ± 0.5 mm, and compression set (JIS K6262) was measured. The compression set was performed at 200 ° C. for 70 hours at 25% compression.

The carbon fiber composite material samples of the crosslinked bodies of Examples 1 to 7 and Comparative Examples 1 to 4 were cut into JIS K 6252 angle-shaped test pieces without incision, and using an autograph AG-X manufactured by Shimadzu Corporation, a tensile speed of 500 mm / Min is measured in accordance with JIS K 6252, the maximum tear force (N) is measured, and the measurement result is divided by the thickness of the test piece to measure the tear strength (N / mm). The area surrounded by the load-displacement curve of the tear test was taken as the tear energy, with the measured load (N) on the vertical axis and the stroke displacement (mm) on the horizontal axis on the horizontal axis.

The crosslinked carbon fiber composite material samples of Examples 1 to 7 and Comparative Examples 1 to 4 were cut into strip-shaped test pieces of 10 mm × width 4 mm × thickness 1 mm as shown in FIG. A notch with a depth of 1 mm is made in the width direction from the center of the side, and using a TMA / SS6100 testing machine manufactured by SII, repeated tensile loads (at 150 ° C., maximum tensile stress 2 N / mm, frequency 1 Hz) in an air atmosphere 0 N / mm to 2 N / mm), and the test piece breaks or the number of pulls up to 1 million times is measured. In Tables 1 and 2, “Tensile fatigue life (times)” is shown. It was. In addition, when it did not break even when the number of tensions reached 1 million times, it was described in Tables 1 and 2 as “1 million interruptions”.

The crosslinked carbon fiber composite material samples of Examples 1, 2, 5 to 7 and Comparative Example 4 were cut into a disk-shaped test piece having a diameter of 8 mm and a thickness of 6 mm, and tested at a load of 49.0 N using a 5 kgf weight. The mass (g) of the test piece before and after the wear test was measured in the same manner as the DIN-53516 wear test except that the wear distance was 20 m and pressed against a # 100 disk-shaped grindstone rotating the piece in water of 25 ° C. The amount of wear Wa = (g ₂ −g ₁ ) / (P · L · d) was obtained by calculation and listed as “DIN wear” in Tables 1 and 2. The unit of the wear amount Wa is cm ³ / N · m. The mass of _{g 1} is a front wear test piece (g), the mass of _{g 2} are after the abrasion test specimen (g), P is the weight of the set load (49N), L is the wear length (m), d is Specific gravity (g / cm ³ ).

The crosslinked carbon fiber composite material samples of Examples 1 and 5 and Comparative Example 4 were cut into disk-shaped test pieces having a diameter of 8 mm and a thickness of 6 mm, and based on NACE (National Association of Corrosion Engineers) TM097-97. Place the test piece in a pressure vessel, pressurize at 5.5 (MPa) with CO ₂ fluid at room temperature for 24 hours, and then rapidly depressurize at a depressurization rate of 1.8 (MPa / second), before and after the test. The volume change of the piece was measured. The volume change was calculated by dV (%) = (Va−Vb) · 100 / Vb. Vb is the volume of the test piece before the test, and Va is the volume of the test piece after the test. Here, the volume change dV is the volume expansion after the test, and is a test for evaluating gas resistance, and is described as “volume expansion (%)” in Tables 1 and 2. The volume of the test piece before the test was measured with an electronic hydrometer, specifically, Va = (Wa−Ww) / dt. Similarly, the volume Vb of the test piece after the test was also calculated. Wa is the weight of the test piece in the air before the test, Ww is the weight of the test piece in the water before the test, and dt is the specific gravity of water corrected by the water temperature.
The measurement results are shown in Tables 1 and 2.

As is clear from the results of Tables 1 and 2, the crosslinked carbon fiber composite material samples of Examples 1 to 7 of the present invention have a higher number of tensile fatigue lives than those of Comparative Examples 1 to 4, and have a high temperature (150 (° C.). In addition, it was found that the crosslinked carbon fiber composite material samples of Examples 1, 2, and 5 to 7 of the present invention had a smaller DIN wear amount than that of Comparative Example 4 and excellent wear resistance. Moreover, it turned out that the carbon fiber composite material sample of the crosslinked body of Examples 1 and 5 has small volume expansion compared with the comparative example 4, and is excellent in gas resistance.

2 Open roll 10 First roll 20 Second roll 30 FEPM
60 Carbon nanofiber 70

Dry compression granulator

72, 74 roll 80 Carbon nanofiber assembly 100 Test piece 106 Notch 110 Chuck 120 DIN abrasion tester 150 Platform 155 Derrick assembly 160 Hole bottom assembly 162 Drill bit 164 Rotation operation system 166 Mud motor

Claims

For tetrafluoroethylene-propylene copolymer (FEPM), including carbon nanofibers,
A seal member having a number of breaks of 10 or more in a tensile fatigue test at 150 ° C., a maximum tensile stress of 2 N / mm, and a frequency of 1 Hz.
In claim 1,
With respect to 100 parts by mass of the tetrafluoroethylene-propylene copolymer (FEPM), 0.5 part by mass to 30 parts by mass of the carbon nanofiber, and 0 part by mass to 50 parts by mass of a filler having an average particle diameter of 5 nm to 300 nm; Including,
The carbon nanofiber has an average diameter of 10 nm to 20 nm,
The amount of the carbon nanofiber and the filler is a sealing member that satisfies the following formulas (1) and (2).
Wt = 0.09W1 + W2 (1)
5 ≦ Wt ≦ 30 (2)
W1: Blending amount of filler (parts by mass)
W2: Compounding amount (parts by mass) of carbon nanofibers.
In claim 2,
A seal member in which the number of breaks in a tensile fatigue test at 150 ° C., a maximum tensile stress of 2 N / mm, and a frequency of 1 Hz is 1,000 times or more.
In claim 1,
4 parts by mass to 30 parts by mass of the carbon nanofibers and 0 part by mass to 60 parts by mass of a filler having an average particle diameter of 5 nm to 300 nm with respect to 100 parts by mass of the tetrafluoroethylene-propylene copolymer (FEPM). Including
The carbon nanofiber has an average diameter of 60 nm to 110 nm,
The amount of the carbon nanofiber and the filler is a sealing member that satisfies the following formulas (3) and (4).
Wt = 0.1W1 + W2 (3)
10 ≦ Wt ≦ 30 (4)
W1: Blending amount of filler (parts by mass)
W2: Compounding amount (parts by mass) of carbon nanofibers.
In claim 4,
A seal member having a compression set of 0% to 40% after being compressed by 25% and after 70 hours at 200 ° C.
In any one of claims 1 to 5,
The wear amount Wa in a high-pressure wear test at 25 ° C. is 0.010 cm 3 / N · m to 0.070 cm 3 / N · m,
The wear amount Wa is a seal member that satisfies the following formula (5).
Wa = (g 2 −g 1 ) / (P · L · d) (5)
g 1 : Mass of the test piece before wear (g)
g 2 : Mass of the test piece after wear (g)
P: Set weight of weight (N)
L: Wear distance (m)
d: Specific gravity (H / cm 3 ).
In any one of claims 1 to 6,
The seal member is a seal member used in an oil field device.
In claim 7,
The oil field device is a seal member that is a logging device that performs logging in a well.
In claim 7,
The seal member is an endless seal member disposed in the oil field device.
In claim 7,
The seal member is a stator of a fluid drive motor disposed in the oil field device.
In claim 10,
The fluid drive motor is a mud motor, a seal member.
In claim 7,
The said sealing member is a sealing member which is a rotor of the fluid drive motor arrange | positioned in the said oil field apparatus.
In claim 12,
The fluid drive motor is a mud motor, a seal member.
In any one of claims 1 to 13,
The tetrafluoroethylene-propylene copolymer (FEPM) has a fluorine content of 50 to 60% by mass, a central value of Mooney viscosity (ML 1 + 4 100 ° C.) of 90 to 160, and a glass transition point of 0 ° C. or less. Seal member.
In any one of claims 1 to 14,
Before the carbon nanofibers are blended with the tetrafluoroethylene-propylene copolymer (FEPM), rigidity = Lx ÷ D (Lx: distance between adjacent defects of the carbon nanofibers) , D: the diameter of the carbon nanofiber), and the average value of the stiffness is 3 to 12, the sealing member.
In claim 2 or 4,
The sealing member, wherein the filler is carbon black having an average particle size of 10 nm to 300 nm.
In claim 2 or 4,
The sealing member has an average particle diameter of 5 nm to 50 nm and is at least one selected from silica, talc and clay.