JP5623998B2 - Carbon fiber composite material, method for producing the same, and liner for prosthetic device - Google Patents

Description

  The present invention relates to a carbon fiber composite material using carbon nanofibers, a method for producing the same, and a liner for a prosthetic limb prosthesis.

  According to the method for producing a carbon fiber composite material previously proposed by the present inventors, the use of an elastomer improves the dispersibility of the carbon nanofiber, which has been considered difficult so far, and makes the carbon nanofiber uniform in the elastomer. (See, for example, Patent Document 1). 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.

  Silicone rubber is generally excellent in physiological inertness, heat resistance, and the like, and is therefore widely used in the fields of automobile parts, medical-related equipment, food-related equipment, and office equipment. However, silicone rubber is excellent in impact resilience and compression set resistance, but tends to be inferior in mechanical properties such as tensile strength and tear strength to other general-purpose rubber. In the medical-related equipment field, for example, silicone rubber has been used for a liner on which a prosthetic limb prosthesis is mounted (for example, Patent Document 2). The silicone rubber liner is required to be sufficiently reinforced so that the liner is not damaged during attachment and detachment while covering and protecting the remaining limbs and maintaining a comfortable cushion property with the socket of the prosthetic device.

JP 2005-97525 A JP 2004-160052 A

  An object of the present invention is to provide a carbon fiber composite material in which carbon nanofibers are dispersed, a method for producing the same, and a liner for a prosthetic device.

The method for producing a carbon fiber composite material according to the present invention includes:
A step (a) of obtaining a first mixture by mixing carbon nanofibers having an average diameter of 0.4 nm to 230 nm with silicone rubber;
A step (b) of kneading the first mixture with an open roll having a roll interval of 0.1 mm or less for 3 minutes to 10 minutes to obtain a second mixture;
Step (c) for obtaining a carbon fiber composite material by thinning the second mixture with an open roll having a roll interval of 0.5 mm or less;
Only including,
The silicone rubber used in the step (a) has an uncured plasticity (based on JIS K6249 plasticity test method) of 50 or more and 800 or less,
The temperature of the first mixture in the step (b) is 0 ° C to 50 ° C,
The torque of the roll immediately before taking out the second mixture in the step (b) is 2 to 10 times the torque of the roll immediately before taking out the first mixture in the step (a). .

  According to the method for producing a carbon fiber composite material according to the present invention, a carbon fiber composite material in which aggregates of carbon nanofibers are disentangled and dispersed can be obtained even when silicone rubber having a small elasticity is used.

In the method for producing a carbon fiber composite material according to the present invention,
The silicone rubber used in the step (a) may have an uncured plasticity (based on JIS K6249 plasticity test method) of 50 or more and 800 or less.

The carbon fiber composite material according to the present invention is a crosslinked product of the carbon fiber composite material obtained by the method for producing the carbon fiber composite material,
The tensile strength is 1.5 MPa to 3.5 MPa, and the elongation at break is 200% to 280%.

A liner for a prosthetic limb prosthesis according to the present invention includes a cylindrical sleeve and an end portion that closes a lower end of the sleeve,
Said sleeve and said end portion, characterized in that the formed crosslinked body of carbon fiber composite material obtained by the method of producing a carbon fiber composite material.

It is a figure which shows typically the manufacturing method of a carbon fiber composite material. It is a figure which shows typically the manufacturing method of a carbon fiber composite material. It is a figure which shows typically the manufacturing method of a carbon fiber composite material. It is a figure which shows typically the manufacturing method of a carbon fiber composite material. It is sectional drawing of the liner for prosthetic limb prosthesis apparatuses. It is a figure which shows typically the tear fatigue test of a carbon fiber composite material. 2 is an electron micrograph of a fracture surface of Example 1. FIG. 2 is an electron micrograph of a fracture surface of Example 1. FIG. 2 is an electron micrograph of a fracture surface of Example 1. FIG. 4 is an electron micrograph of a fracture surface of Comparative Example 2. 4 is an electron micrograph of a fracture surface of Comparative Example 2. 4 is an electron micrograph of a fracture surface of Comparative Example 2.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The method for producing a carbon fiber composite material according to one embodiment of the present invention includes a step (a) of obtaining a first mixture by mixing carbon nanofibers having an average diameter of 0.4 nm to 230 nm with silicone rubber; The step (b) of obtaining the second mixture by kneading the first mixture with an open roll having a roll interval of 0.1 mm or less for 3 minutes to 10 minutes, and the second mixture having a roll interval of 0.5 mm or less a step of obtaining the carbon fiber composite material performing tight milling an open roll (c), seen including a silicone rubber used for the step (a), plasticity in the uncured state (JIS
K6249 plasticity test method) is 50 or more and 800 or less, the temperature of the first mixture in the step (b) is 0 ° C. to 50 ° C., and the second mixture in the step (b) is taken out. The torque of the roll immediately before is characterized by being 2 to 10 times the torque of the roll immediately before taking out the first mixture in the step (a) . A carbon fiber composite material according to an embodiment of the present invention is a crosslinked product of a carbon fiber composite material obtained by the method for producing a carbon fiber composite material, and has a tensile strength of 1.5 MPa to 3.5 MPa. And elongation at break is 200% to 280%. A liner for a prosthetic limb prosthesis according to an embodiment of the present invention includes a cylindrical sleeve and an end portion that closes a lower end of the sleeve, and the sleeve and the end portion are made of the carbon fiber composite material. It is characterized by being formed of a crosslinked product of a carbon fiber composite material obtained by the production method.

  The silicone rubber used in the method for producing the carbon fiber composite material can be a raw rubber of polyorganosiloxane, the main chain is composed of siloxane bonds, and the side chain is an alkyl such as methyl group, ethyl group, propyl group or butyl group. Group, cycloalkyl group such as cyclohexyl group, vinyl group, allyl group, butenyl group, alkenyl group such as hexenyl group, aryl group such as phenyl group, tolyl group, aralkyl group such as benzyl group, γ-phenylpropyl group, or A group in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a halogen atom, a cyano group, or the like, for example, a chloromethyl group, a trifluoropropyl group, a cyanoethyl group, or the like can be included. The molecular structure of the silicone rubber can be linear, and can be linear with some branching. The silicone rubber is a millable silicone rubber, and a heat vulcanizing silicone rubber can be used. The silicone rubber can have an uncured plasticity (based on JIS K6249 plasticity test method) of 50 or more and 800 or less. The plasticity is a so-called Williams plasticity, and a plasticity test method defined in JIS K6249 “Testing method for uncured and cured silicone rubber” using a parallel plate plasticity meter (Williams Plastometer) at 25 ° C. It can measure according to.

  Carbon nanofibers used in the method for producing a carbon fiber composite material have an average diameter (fiber diameter) of 0.4 nm to 230 nm. Furthermore, the carbon nanofibers can have an average diameter (fiber diameter) of 9 nm to 110 nm, in particular 9 nm to 20 nm or 60 nm to 110 nm. Since carbon nanofibers have a relatively thin average diameter, the specific surface area is large, the surface reactivity with silicone rubber as a matrix is improved, and carbon nanofibers can be defibrated and dispersed throughout. Silicone rubber can be effectively reinforced with a small amount of carbon nanofibers. In particular, the raw rubber of silicone rubber having low viscosity and low plasticity cannot easily disperse carbon nanofibers. Therefore, by using carbon nanofibers having a relatively large average diameter of 60 nm to 110 nm among carbon nanofibers, Dispersibility can be improved. Silicone rubber can be reinforced by using carbon nanofibers having an average diameter (fiber diameter) of 0.4 nm to 230 nm. 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. From past research results, it has been found that the maximum diameter of one cell is approximately twice to 10 times the average diameter of carbon nanofibers. The average diameter of the carbon nanofiber can be measured by observation with an electron microscope. The carbon nanofibers can be oxidized to improve the reactivity with the silicone rubber on the surface. 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.

  The compounding quantity of the carbon nanofiber in a carbon fiber composite material can be mix | blended suitably according to a desired characteristic. In the carbon fiber composite material, 5 parts by mass or more and 100 parts by mass or less of carbon nanofibers can be blended with 100 parts by mass of silicone rubber, and further 10 parts by mass or more and 60 parts by mass or less of carbon nanofibers can be blended. In particular, 15 parts by mass or more and 25 parts by mass or less of carbon nanofibers can be blended. When the carbon nanofiber is 5 parts by mass or more with respect to 100 parts by mass of the silicone rubber in the carbon fiber composite material, tear fatigue durability can be improved, and if it is 100 parts by mass or less, the carbon fiber can be processed. In addition to carbon nanofibers, carbon fiber composite materials may use, for example, metal oxides such as silica, alumina, magnesium oxide, and zinc oxide, and carbon black as reinforcing fillers that are generally used for silicone rubber. it can. Here, “parts by mass” indicates “phr” unless otherwise specified, and “phr” is an abbreviation for “parts per undred of resin or rubber”, and represents the percentage of external additives such as additives to rubber and the like. It is.

  Carbon nanofibers are so-called multi-wall carbon nanotubes (MWNT: multi-wall carbon nanotubes) having a cylindrical shape formed by winding one sheet of graphite (graphene sheet) having a carbon hexagonal mesh surface, and an average diameter of 10 to 20 nm. Examples of carbon nanofibers include Baytubes C150P and C70P manufactured by Bayer MaterialScience, and NC-7000 manufactured by Nanocyl. Examples of carbon nanofibers having an average diameter of 60 nm to 110 nm include For example, NT-7 of Hodogaya Chemical Co., Ltd. can be mentioned. 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 referred to as catalytic chemical vapor deposition (CCVD), in which a gas such as hydrocarbon is pyrolyzed in the presence of a metal catalyst to vaporize the first carbon nano-particles that have not been treated. 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. Introduced into a reactor set at a reaction temperature of ~ 1000 ° C and floated or generated the first carbon nanofiber on the reactor wall. A catalyst-supported 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 9 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 9nm~20nm may nitrogen adsorption specific surface area of ^{10m 2} / ^g~500m 2 / g, can be more 100m ² / g~350m ² / g, in particular, it can be a 150m ² / g~300m ² / g.

The manufacturing method of a carbon fiber composite material The manufacturing method of the carbon fiber composite material concerning one embodiment of this invention mixes carbon nanofiber with an average diameter of 0.4 nm-230 nm to silicone rubber, and obtains a 1st mixture. Step (a), Step (b) of kneading the first mixture with an open roll having a roll interval of 0.1 mm or less for 3 minutes to 10 minutes to obtain a second mixture, and the second mixture having a roll interval of And a step (c) of obtaining a carbon fiber composite material by thinning with an open roll of 0.5 mm or less. The manufacturing method of a sealing member is demonstrated in detail using FIGS. 1-4.

  1-4 is a figure which shows typically the manufacturing method of the sealing member by the open roll method concerning one Embodiment of this invention.

  As shown in FIGS. 1-4, the 1st roll 10 and the 2nd roll 20 in the open roll 2 of 2 rolls are arrange | positioned by the predetermined space | interval d, for example, the space | interval of 0.5 mm-1.5 mm. 1 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. 1, a raw rubber silicone rubber 30 is wound around the first roll 10. The silicone rubber 30 has a small plasticity and can be barely wound around the first roll 10.

  Next, as shown in FIG. 2, in the step (a), carbon nanofibers 80 and a filler (not shown) are loaded into the bank 34 of the silicone rubber 30 wound around the first roll 10 as necessary. And mixing to obtain a first mixture. The temperature of the silicone rubber 30 in this kneading can be, for example, 0 ° C. to 50 ° C., and further can be 10 ° C. to 20 ° C. In the step (a), since the silicone rubber 30 has a low plasticity, the carbon nanofibers are only dispersed as a whole even if kneaded, and the carbon nanofiber aggregates can be defibrated. Almost not done. The kneading in the step (a) can be, for example, kneading such that the carbon nanofibers enter the silicone rubber visually. The step (a) 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.

Next, as shown in FIG. 3, in the step (b), the roll interval d between the first roll 10 and the second roll 20 is set to an interval of 0.1 mm or less, and the first mixture 35 It is wound around the first roll 10 and kneaded for 3 to 10 minutes to obtain a second mixture. The roll interval d in the step (b) is 0.1 mm or less, and can be appropriately adjusted in the range of 0 to 0.1 mm that can be processed depending on the size of the open roll and the processing amount of the mixture. The kneading time in the step (b) is 3 minutes to 10 minutes, can be further 4 minutes to 8 minutes, and particularly 4 minutes to 6 minutes. The temperature of the first mixture 35 in the kneading is 0 ° C. to 50 ° C.. Et al., Temperature of the first mixture 35 in the kneading may be 10 ° C. to 20 ° C.. By mixing the carbon nanofibers 80, the first mixture 35 has higher plasticity than the raw rubber silicone rubber 30, and the elasticity can be gradually increased by performing the step (b). The torque of the roll immediately before taking out the second mixture in step (b) can be higher than the torque of the roll immediately before taking out the first mixture in step (a). Roll torque immediately before taking out the second mixture of step (b), Ru der 10 times or less than 2 times the roll torque immediately before taking out the first mixture in step (a). Et al is a roll torque immediately before taking out the second mixture of step (b) can in step (a) is not more than 10 times more than three times the roll torque immediately before taking out the first mixture . By performing additional kneading until the torque of the roll becomes sufficiently high in the step (b), the strength of the second mixture can be improved, and the elasticity of the second mixture can be improved. Further, by kneading with a narrow roll interval d in the step (b), the silicone rubber molecular chain is appropriately cut to generate free radicals, and the free radicals of the silicone rubber molecules and the carbon nanofibers are easily combined. I can guess. The roll torque is a load applied to the roll in the open roll, and generally the open roll is always measured and displayed.

  Further, as shown in FIG. 4, in the step (c), 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. After setting, the second mixture 36 is put into the open roll 2 for thinning. For example, the thinning can be performed about 1 to 10 times. The carbon fiber composite material 50 pushed out 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 silicone rubber, and the carbon nanofibers move together with the silicone rubber. 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 second mixture 36 and The actually measured temperature of the carbon fiber composite material 50 can also be adjusted to 0 to 50 ° C.

  In the steps (a) to (c), when the surface speed of the first roll 10 is V1, and the surface speed of the second roll 20 is V2, the surface speed ratio (V1 / V2) of both in thin passage is: It can be 1.05 to 3.00, and can further be 1.05 to 1.2. By using such a surface velocity ratio, a desired shear force can be obtained particularly in the step (b) and the step (c).

The carbon fiber composite material thus obtained had a first spin-spin relaxation time (T2n) of 100 in a non-crosslinked body measured at 150 ° C. by a Hahn echo method using pulsed NMR and at ¹ H of the observation nucleus. The component fraction (fnn) of the component having the second spin-spin relaxation time can be 0-0.2, in particular, the component having the second spin-spin relaxation time. The component fraction (fnn) can be zero. T2n and fnn measured at 150 ° C. of the carbon fiber composite material represent the molecular mobility of the silicone rubber molecule, and can represent that the carbon nanofibers are uniformly dispersed in the silicone rubber as a matrix. In other words, the fact that the carbon nanofibers are uniformly dispersed in the silicone rubber can be said to be in a state where the molecules of the silicone rubber are restrained by the carbon nanofibers. In this state, the mobility of the silicone rubber molecules constrained by the carbon nanofibers is smaller than that when not constrained by the carbon nanofibers. Further, the spin-lattice relaxation time (T1) measured by the inversion recovery method using pulsed NMR is a scale representing the molecular mobility of the substance together with the first spin-spin relaxation time (T2n). Therefore, the first spin-spin relaxation time (T2n) and the spin-lattice relaxation time (T1) of the carbon fiber composite material are shorter than those of the silicone rubber alone that does not include carbon nanofibers, and the carbon nanofibers are particularly uniform. It becomes shorter by dispersing in

  Due to the shearing force obtained in the step (c), a high shearing force acts on the silicone rubber, so that the aggregated carbon nanofibers are separated from each other so as to be pulled out one by one into the silicone rubber molecule, and into the silicone rubber. Distributed. In particular, the second mixture is improved in elasticity as a result of the silicone rubber molecules being restrained by the carbon nanofibers by kneading until the torque of the roll is sufficiently high in step (b). And chemical interaction with the carbon nanofibers, and the carbon nanofibers can be dispersed in the step (c). And the carbon fiber composite material excellent in the dispersibility and dispersion stability of carbon nanofiber (it is hard to re-aggregate carbon nanofiber) can be obtained.

  More specifically, when silicone rubber and carbon nanofibers are mixed with an open roll, viscous silicone rubber penetrates into the carbon nanofibers, and a specific part of the silicone rubber is carbonized by chemical interaction. It binds to the highly active part of the nanofiber. If the activity of the surface of the carbon nanofiber is moderately high, it can be particularly easily bonded to silicone rubber molecules. Next, when a strong shearing force acts on the silicone rubber, the carbon nanofibers also move with the movement of the silicone rubber molecules, and the elasticity is particularly improved in the step (b). The agglomerated carbon nanofibers are separated and dispersed in the silicone rubber by the restoring force of the silicone rubber due to the elasticity of. According to this embodiment, when the carbon fiber composite material is extruded from between narrow rolls, the carbon fiber composite material is thicker than the roll interval due to the restoring force due to the elasticity of the second mixture obtained by the step (b). Deform. 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 silicone rubber. The carbon nanofibers once dispersed are prevented from reaggregating due to chemical interaction with the silicone rubber, and can have good dispersion stability.

  The step of dispersing the carbon nanofibers in the silicone rubber by a shearing force is not limited to the open roll method, and a closed kneading method or a multiaxial 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 silicone rubber. 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 carbon fiber composite material that has been dispensed before, during, or after passing through the silicone rubber and carbon nanotubes, and the cross-linked carbon fiber composite material can be cross-linked. Can do. The silicone rubber can be crosslinked with a known crosslinking agent, for example, with peroxide.

  The sealing member is formed into a desired shape, for example, an endless shape by a molding process of silicone rubber, which is generally employed, such as an injection molding method, a transfer molding method, a press molding method, an extrusion molding method, a calendering method, etc. Can be obtained. 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 that is usually used in the processing of silicone rubber 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 silicone rubber at an appropriate time during the mixing process. As the cross-linking agent, peroxide can be used, for example, before carbon nanofibers are mixed with silicone rubber, together with carbon nanofibers, or after carbon nanofibers and silicone rubber are mixed, In order to prevent this, the crosslinking agent can be blended into the uncrosslinked carbon fiber composite material after passing through.

  The carbon fiber composite material formed in this way can reinforce the silicone rubber with carbon nanofibers, thereby improving the tensile test characteristics including rigidity, and also improving the tear strength, which was a drawback of the silicone rubber. The cross-linked carbon fiber composite material has, for example, a tensile strength of 1.5 MPa to 3.5 MPa in a tensile test based on JIS K6251 at 23 ± 2 ° C. and a tensile speed of 500 mm / min, and elongation at break. Can be 200% to 280%, furthermore, the tensile strength can be 1.8 MPa to 3.2 MPa, and the elongation at break can be 230% to 270%. Is 2.0 MPa to 3.0 MPa, and the elongation at break is 240% to 260%. Further, the carbon fiber composite material can have a long life (the number of pulls) until it breaks in the tear fatigue test. The tear fatigue test can also be used as an evaluation of the wear resistance of a material.

  In addition, around the carbon nanofibers, a part of the silicone rubber is broken during molecular kneading, and free radicals generated thereby attack the surface of the carbon nanofibers and adsorb the silicone rubber molecule aggregates. Possible interface phases are 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 a silicone that is divided into nanometer sizes surrounded by an interfacial phase in which interfacial phases are chained together by blending a predetermined amount or more of carbon nanofibers. Estimated to form small cells of rubber. 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, the carbon fiber composite material obtained by one Embodiment of this invention can be used for the liner for prosthetic device prosthesis. As described above, this carbon fiber composite material is particularly useful for a liner because it has excellent tensile properties, tear strength, and tear fatigue life properties. Below, the liner for prosthetic limb prostheses shape | molded with the carbon fiber composite material is demonstrated.

  The liner 200 includes a cylindrical sleeve 210 into which the remaining limbs are inserted, a dome-shaped end portion 212 that closes the lower end of the sleeve 210, and a metal fitting 214 that protrudes outward from the central front end portion of the end portion 212. Including. The sleeve 210 and the end portion 212 can be inserted into a socket made of a relatively hard material of a prosthetic device (not shown), and can have a comfortable cushion between the remaining limbs and the socket. The metal fitting 214 can be coupled to a coupling member of a prosthetic limb prosthesis device (not shown). The sleeve 210 and the end portion 212 can be formed by a crosslinked body of carbon fiber composite material using silicone rubber as a matrix material. By using a carbon fiber composite material, the liner 200 can have excellent resilience and compression set resistance, as well as excellent tensile strength and tear strength.

  Although the embodiments of the present invention have been described in detail as described above, 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.

(1) Preparation of Samples of Examples 1-2 and Comparative Examples 1-2 Hereinafter, examples of the present invention will be described, but the present invention is not limited to these.

  Step (a): Silicone rubber (“silicone” in Table 1) is introduced into an open roll (roll temperature: 10 to 20 ° C., roll interval: 0.5 mm to 1.0 mm). Fibers ("MWCNT-1" and "MWCNT-2" in Table 1) were put into silicone rubber and mixed for 10 minutes, and then the first mixture was taken out of the roll. The torque of the roll immediately before removing the first mixture from the roll was 0.3 kN.

  Step (b): Next, the first mixture is wound around an open roll (roll temperature 10 to 20 ° C., roll interval 0.1 mm), kneaded for 5 minutes, and the second mixture is taken out of the roll. It was. The torque of the roll immediately before removing the second mixture from the roll was 1.0 kN.

  Step (c): Further, the second mixture was repeatedly thinned five times with an open roll set at a roll interval of 0.1 mm. The surface speed ratio of the two rolls in steps (a) to (c) was 1.1.

  In accordance with the composition shown in Table 1, peroxide (PO) was added as a crosslinking agent and kneaded into the uncrosslinked carbon fiber composite material obtained through thinning, and the separated sheet was subjected to press crosslinking (170 ° C./10 minutes). ) And secondary cross-linking (200 ° C./4 hours) to obtain a cross-linked sample of sheet-like carbon fiber composite materials of Examples 1 and 2 having a thickness of 1 mm. Comparative Example 1 is a cross-linked sample obtained by cross-linking silicone rubber alone, and Comparative Example 2 is a carbon fiber composite obtained by performing Step (a) and Step (c) without going through Step (b). It was a cross-linked sample of the material.

  In Table 1, “silicone rubber” in Examples 1 and 2 and Comparative Examples 1 and 2 has a specific gravity (23 ° C.) of 0.98, a JIS K6249 Williams plasticity (23 ° C., 3 minutes) of 96, and a heat loss ( (150 ° C., 24 hours) 3.0 dimethylvinylsilicone raw rubber, “MWCNT-1” is a multi-walled carbon nanotube having an average diameter of 67 nm graphitized by high-temperature heat treatment, “MWCNT-2” is a multi-walled carbon nanotube having an average diameter of 67 nm that has been heat-treated It was a carbon nanotube.

About the sample of the carbon fiber composite material of Example 1 and the comparative example 1 of the non-crosslinked body which does not mix | blend the crosslinking agent, the measurement by the Hahn echo method and the inversion recovery method was performed using pulse method NMR. This measurement was performed using “JMN-MU25” manufactured by JEOL Ltd. The measurement was performed under the conditions of the observation nucleus of ¹ H, the resonance frequency of 25 MHz, and the 90 ° pulse width of 2 μsec. The Pi was changed in various ways using the pulse sequence of the Hahn-echo method (90 ° x-Pi-180 ° x). The decay curve was measured. Further, the sample was measured by inserting it into a sample tube up to an appropriate range of the magnetic field. The measurement temperature was 150 ° C. The measurement results are shown in Table 1 as T1, T2n, and fnn as NMR.

(2) Physical test About the crosslinked body sample of Examples 1-2 and Comparative Examples 1-2, rubber hardness (Hs (JIS-E)) was measured based on JISK6253.

  About the test piece which pierced the bridge | crosslinking body sample of Examples 1-2 and Comparative Examples 1-2 into the dumbbell shape of JIS6 type, 23 ± 2 degreeC using the Shimadzu Corporation autograph AG-X tensile tester. A tensile test was performed based on JIS K6251 at a tensile speed of 500 mm / min, 50% stress (σ50 (MPa)), 100% stress (σ100 (MPa)), tensile strength (TS (MPa)), and elongation at break. (Eb (%)) was measured. Moreover, the fracture surface of the crosslinked body sample fractured in the tensile test was observed with an electron microscope. 7 to 9 are fracture surfaces of Example 1, and FIGS. 10 to 12 are fracture surfaces of Comparative Example 2. FIG. The magnification of the electron microscope was 50 times in FIGS. 7 and 10, 1000 times in FIGS. 8 and 11, and 2000 times in FIGS. 9 and 12.

  The crosslinked body samples of Examples 1 and 2 and Comparative Examples 1 and 2 were punched into angle-shaped test pieces without incision in JIS K 6252, and JIS K was used at a tensile speed of 500 mm / min using an autograph AG-X manufactured by Shimadzu Corporation. A tear test was performed according to 6252, the maximum tear force (N) was measured, and the measurement result was divided by the thickness of 1 mm of the test piece to measure the tear strength (TR (N / mm)).

  The crosslinked body samples of Examples 1 and 2 and Comparative Examples 1 and 2 are punched into a strip-shaped test piece 100 having a size of 10 mm × width 4 mm × thickness 1 mm as shown in FIG. A razor blade is used to insert a notch 106 having a depth of 1 mm in the width direction, and the short sides 104 and 104 near both ends of the test piece 100 are held by chucks 110 and 110 using a TMA / SS6100 testing machine manufactured by SII. In a 200 ° C. air atmosphere, a tensile fatigue test is performed by repeatedly applying a tensile load (0 N / mm to 2 N / mm) in the direction of arrow T in FIG. ((A) Fatigue (times)) was measured.

  The measurement results are shown in Table 2. The rubber hardness is “Hs (JIS-E)”, the 50% stress is “σ50 (MPa)”, the 100% stress is “σ100 (MPa)”, and the tensile strength is “TS ( MPa) ”, elongation at break“ Eb (%) ”, tear strength“ TR (N / mm) ”, and number of tear fatigue lives“ (a) fatigue (times) ”.

  According to Table 2, 50% stress (MPa), 100% stress (MPa), tensile strength (MPa), elongation at break (%), tear strength (N / mm) and tear life (times) are Although the crosslinked body sample of Comparative Example 2 was improved as compared with Comparative Example 1, the crosslinked body samples of Examples 1 and 2 were further improved than Comparative Example 2. T2n of the uncrosslinked body sample of Example 1 was shorter than T2n of the uncrosslinked body sample of Comparative Example 1.

  A large number of aggregates of carbon nanofibers were observed on the fracture surface of Comparative Example 2 in FIGS. 10 to 12, and aggregates having a diameter of 20 μm or more could be observed. On the other hand, on the fracture surface of Example 1 in FIGS. 7 to 9, no agglomerates of carbon nanofibers are observed, and it can be observed that the carbon nanofibers are defibrated and dispersed throughout. It was.

  2 Open roll, 10 1st roll, 20 2nd roll, 30 Elastomer, 34 bank, 36 2nd mixture, 50 carbon fiber composite material, 80 carbon nanofiber, V1, V2 rotational speed, 100 specimen, 106 Incision, 110 chuck, 150 platform, 151 derrick knitting, 151a hook, 151b swivel swivel, 151c kelly, 151d rotary table, 152 sea, 153 drill string, 154 seabed, 155 surface, 156 well, 156a bottom, 160 well Bottom equipment organization, 160 'downhole device, 162 drill bit, 164 rotary operation system, 166 mud motor, 168 simultaneous drilling measurement module, 170 simultaneous drilling logging module

Claims (4)

A step (a) of obtaining a first mixture by kneading carbon nanofibers having an average diameter of 0.4 nm to 230 nm with silicone rubber;
A step (b) of kneading the first mixture with an open roll having a roll interval of 0.1 mm or less for 3 minutes to 10 minutes to obtain a second mixture;
Step (c) for obtaining a carbon fiber composite material by thinning the second mixture with an open roll having a roll interval of 0.5 mm or less;
Only including,
The silicone rubber used in the step (a) has an uncured plasticity (based on JIS K6249 plasticity test method) of 50 or more and 800 or less,
The temperature of the first mixture in the step (b) is 0 ° C to 50 ° C,
The carbon fiber composite material , wherein the torque of the roll immediately before taking out the second mixture in the step (b) is 2 to 10 times the torque of the roll just before taking out the first mixture in the step (a). Manufacturing method. Oite to claim 1,
The said carbon nanofiber is a manufacturing method of a carbon fiber composite material whose average diameter is 60 nm-150 nm. A cross-linked carbon fiber composite material obtained by the method for producing a carbon fiber composite material according to claim 1 or 2 ,
A carbon fiber composite material having a tensile strength of 1.5 MPa to 3.5 MPa and an elongation at break of 200% to 280%. A cylindrical sleeve, and an end closing the lower end of the sleeve,
A sleeve for a prosthetic limb prosthesis, wherein the sleeve and the end are formed of a cross-linked body of a carbon fiber composite material obtained by the method for producing a carbon fiber composite material according to claim 1 or 2 .