JP2023124728A - Elastomer composition, crosslinked product and molding - Google Patents

Abstract

To provide an elastomer composition capable of forming a molding having low surface resistivity and excellent mechanical strength under a high-temperature environment.SOLUTION: An elastomer composition includes an elastomer, carbon nanotubes satisfying predetermined conditions, and a compound A. A distance R1 in Hansen solubility parameters between the carbon nanotubes and the compound A is 1.0 MPa1/2 or more and 10.0 MPa1/2 or less. A distance R2 in Hansen solubility parameters between the elastomer and the compound A is greater than the distance R1.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to an elastomer composition, a crosslinked product obtained by crosslinking the elastomer composition, and a molded article made of the crosslinked product.

2. Description of the Related Art Conventionally, an elastomer composition obtained by blending an elastomer with a carbon material has been used as a material having excellent properties such as electrical conductivity, thermal conductivity and strength. In recent years, attention has been focused on carbon nanotubes (hereinafter sometimes abbreviated as “CNT”) as a carbon material that is highly effective in improving the above properties.

Here, CNTs have excellent individual properties, but because they have a small outer diameter, they are easily bundled by van der Waals force when used as a bulk material. Therefore, when producing a molded article using an elastomer composition containing an elastomer and CNTs, it is required to defibrate the CNT bundle structure and to disperse the CNTs satisfactorily in the elastomer matrix. .

Therefore, for example, Patent Document 1 proposes a technique for dispersing CNTs satisfactorily in an elastomer matrix by blending a predetermined compound A. Specifically, in Patent Document 1, an elastomer composition in which CNTs are well dispersed contains an elastomer, carbon nanotubes, and a compound A having a freezing point of 40° C. or lower, and the Hansen solubility of the carbon nanotubes and the compound A is Elastomeric compositions are disclosed having a parameter distance R1 of 6.0 MPa ^1/2 or less and a Hansen Solubility Parameter distance R2 between the elastomer and Compound A greater than R1.

WO2021/172555

However, the above conventional elastomer compositions have room for improvement in terms of further reducing the surface resistivity of molded articles formed using the elastomer compositions and increasing the mechanical strength in high-temperature environments. .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an elastomer composition capable of forming a molded article having a low surface resistivity and excellent mechanical strength in a high temperature environment.
Another object of the present invention is to provide a crosslinked product and a molded product which have low surface resistivity and excellent mechanical strength in a high temperature environment.

The inventor of the present invention has made intensive studies in order to achieve the above object. Then, the present inventors found that if an elastomer composition containing a compound containing an elastomer and predetermined CNTs and further satisfying predetermined conditions for the distance of the Hansen Solubility Parameter between the elastomer and the CNTs is used, the surface resistivity can be improved. The inventors have found that it is possible to produce a molded article having a low C and excellent mechanical strength in a high-temperature environment, and completed the present invention.

That is, an object of the present invention is to advantageously solve the above problems, and an elastomer composition of the present invention comprises an elastomer, carbon nanotubes, and a compound A, wherein the carbon nanotubes and the compound A is 1.0 MPa ^1/2 or more and 10.0 MPa ^1/2 or less, and the Hansen solubility parameter distance R2 between the elastomer and the compound A is greater than the distance R1, The carbon nanotubes meet the following conditions (1) to (3):
(1) The plasmon resonance of the carbon nanotube dispersion in the spectrum obtained by Fourier transform infrared spectroscopic analysis of the carbon nanotube dispersion obtained by dispersing the carbon nanotubes so that the bundle length is 10 μm or more. (2) For ^the carbon nanotubes, from the adsorption isotherm of liquid nitrogen at 77 ^K , based on the Barrett-Joyner-Halenda method (3) The two-dimensional electron microscope image of the carbon nanotube At least one peak of the spatial frequency spectrum is present in the range of 1 μm ⁻¹ to 100 μm ⁻¹ . As described above, if a predetermined CNT and the compound A satisfying predetermined conditions of the Hansen Solubility Parameter distance between the elastomer and the CNT are contained, the surface resistance of the molded article formed using the elastomer composition is obtained. It is possible to reduce the modulus and improve the mechanical strength in a high temperature environment.

Here, in the elastomer composition of the present invention, the content of compound A is preferably 10.0% by mass or less. When the content of compound A is equal to or less than the above upper limit, the mechanical strength of a molded article formed using the elastomer composition can be further enhanced in a high-temperature environment.
In the present invention, the content of Compound A in the elastomer composition can be measured using the method described in Examples.

Moreover, in the elastomer composition of the present invention, the elastomer is preferably at least one selected from the group consisting of fluororubbers, hydrogenated nitrile rubbers, butadiene rubbers and silicone rubbers. By using these rubbers, the CNTs can be well dispersed in the elastomer composition, and the surface resistivity of a molded article formed using the elastomer composition can be further reduced, while the mechanical strength under high temperature environments can be further increased. can be done.

Furthermore, in the elastomer composition of the present invention, the compound A is preferably a compound having an aromatic ring. If the compound A is a compound having an aromatic ring, the CNTs can be well dispersed in the elastomer composition, and the surface resistivity of the molded article formed using the elastomer composition can be further reduced while maintaining mechanical properties in a high-temperature environment. Strength can be further increased.

Further, in the elastomer composition of the present invention, the compound A is preferably a phenyl ester compound. If the compound A is a phenyl ester compound, the CNTs can be well dispersed in the elastomer composition, and the mechanical strength in a high-temperature environment can be improved while further reducing the surface resistivity of the molded article formed using the elastomer composition. can be further increased.

Furthermore, the elastomer composition of the present invention preferably contains 0.1 parts by mass or more and 10 parts by mass or less of the carbon nanotubes per 100 parts by mass of the elastomer. If the content of the carbon nanotubes is within the above range, the CNTs can be well dispersed in the elastomer composition, and the surface resistivity of the molded article formed using the elastomer composition can be further reduced, and the mechanical properties under a high temperature environment can be improved. It is possible to further increase the target strength.

Further, in the elastomer composition of the present invention, the carbon nanotubes are preferably single-walled carbon nanotubes. By using single-walled carbon nanotubes, it is possible to further reduce the surface resistivity of the molded article formed using the elastomer composition and further increase the mechanical strength in a high-temperature environment.

The elastomer composition of the present invention preferably further contains a cross-linking agent. Elastomer compositions containing cross-linking agents are useful as materials for cross-linked products and moldings.

Another object of the present invention is to advantageously solve the above-mentioned problems, and the cross-linked product of the present invention is characterized by cross-linking the elastomer composition. A cross-linked product obtained by cross-linking the elastomer composition described above has a low surface resistivity and excellent mechanical strength in a high-temperature environment.

A further object of the present invention is to advantageously solve the above-described problems, and the molded article of the present invention is characterized by comprising the above-described crosslinked product. A molded article made of a cross-linked product obtained by cross-linking the elastomer composition described above has a low surface resistivity and excellent mechanical strength in a high-temperature environment.

ADVANTAGE OF THE INVENTION According to this invention, the elastomer composition which can form the molded object which has a low surface resistivity and is excellent in mechanical strength in a high temperature environment can be provided.
Moreover, according to the present invention, it is possible to provide a crosslinked product and a molded product that have low surface resistivity and excellent mechanical strength in a high-temperature environment.

Schematic structure of an example of a CNT manufacturing apparatus is shown. The schematic structure of another example of a CNT manufacturing apparatus is shown.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
Here, the elastomer composition of the present invention can be used for producing the crosslinked product and molded article of the present invention.

(Elastomer composition)
The elastomer composition of the present invention comprises an elastomer, CNTs, compound A, and optionally further contains a cross-linking agent and/or additives.

Here, in the elastomer composition of the present invention, the distance R1 between the CNT and the compound A in the Hansen solubility parameter is 1.0 MPa ^1/2 or more and 10.0 MPa ^{1/2 or} less, and the Hansen solubility parameter between the elastomer and the compound A is greater than R1. Therefore, by using the elastomer composition of the present invention, it is possible to obtain a molded article in which CNTs are well dispersed in the elastomer, which has a low surface resistivity and high mechanical strength in a high-temperature environment. The reason for this is not clear, but is presumed to be as follows.
That is, in the elastomer composition of the present invention, since the value of R1 is within the above-specified range, the compound A has excellent affinity with CNT, and the compound A impregnates the inside of the CNT bundle structure, thereby forming the bundle. Promotes defibration of the structure. In addition, since the value of R2 is greater than the value of R1, compound A has better affinity with CNTs than with elastomers, and the presence of elastomers may excessively inhibit the defibration of the bundle structure by compound A described above. do not have. Therefore, it is considered that the use of the elastomer composition described above enables the CNT bundle structure to be sufficiently fibrillated to obtain a molded article in which the CNTs are well dispersed in the elastomer.

<Elastomer>
The elastomer is not particularly limited, and any rubber, resin, or mixture thereof can be used, for example.
Specifically, the rubber is not particularly limited, and examples include natural rubber; vinylidene fluoride rubber (FKM), tetrafluoroethylene-propylene rubber (FEPM), tetrafluoroethylene-purple vinyl ether rubber. Fluorine rubber such as (FFKM); butadiene rubber (BR), isoprene rubber (IR), styrene-butadiene rubber (SBR), hydrogenated styrene-butadiene rubber (H-SBR), nitrile rubber (NBR), hydrogenated nitrile rubber diene rubber such as (H-NBR); silicone rubber;
In addition, the resin is not particularly limited, and examples thereof include fluororesins such as polytetrafluoroethylene (PTFE); acrylic resins such as polymethyl methacrylate (PMMA); polystyrene (PS); polycarbonate (PC); is mentioned.

Among the above-described elastomers, fluororubber, hydrogenated nitrile rubber, butadiene rubber and silicone rubber are preferred, and fluororubber is more preferred. By using an elastomer composition containing at least one of these elastomers, it is possible to obtain a molded article in which CNTs are better dispersed in the elastomer.
In addition, these elastomers can be used individually by 1 type or in mixture of 2 or more types.

<Carbon nanotube>
The carbon nanotubes contained in the elastomer composition of the present invention satisfy at least one of the following conditions (1) to (3) and have excellent dispersibility.
(1) A carbon nanotube dispersion obtained by dispersing carbon nanotubes so that the bundle length is 10 μm or more. Based on the plasmon resonance of the carbon nanotube dispersion in the spectrum obtained by Fourier transform infrared spectrophotometry. At least one peak exists in the wavenumber range of more than 300 cm ⁻¹ to 2000 cm ⁻¹ or less.
(2) The maximum peak in the differential pore volume distribution measured for carbon nanotubes is in the pore diameter range of more than 100 nm and less than 400 nm.
(3) At least one peak in the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube exists in the range of 1 μm ⁻¹ to 100 μm ⁻¹ .

Although the reason why CNTs satisfying at least one of the above conditions (1) to (3) are excellent in dispersibility is not clear, it is presumed to be as follows. CNTs that satisfy at least one of the above conditions (1) to (3) have a wavy structure, and it is speculated that interactions between CNTs can be suppressed due to such a "wavy structure." . Then, if the interaction between the CNTs is suppressed, the strong bundling and agglomeration of the CNTs can be suppressed. This may allow the CNTs to be easily dispersed. Conditions (1) to (3) will be described in detail below.

-Condition (1)
The condition (1) is that "a carbon nanotube dispersion obtained by dispersing carbon nanotubes so that the bundle length is 10 μm or more, the spectrum obtained by Fourier transform infrared spectroscopic analysis shows that the carbon nanotube dispersion There is at least one peak based on plasmon resonance in the wave number range of more than 300 cm ⁻¹ and 2000 cm ⁻¹ or less.”.

In condition (1), the peak based on the plasmon resonance of CNTs preferably exists in the wavenumber range of 500 cm ^{−1 or} more and 2000 cm ⁻¹ or less, more preferably in the wavenumber range of 650 cm ⁻¹ or more and 2000 cm ⁻¹ or less.

In the spectrum obtained by Fourier transform infrared spectrophotometry, in addition to the relatively gentle peaks based on the plasmon resonance of the carbon nanotube dispersion, wave numbers near 840 cm ^-1 , near 1300 cm ^-1 , and near 1700 cm ^-1 , a sharp peak may be observed. These sharp peaks do not correspond to "peaks based on plasmon resonance of carbon nanotube dispersion", and each corresponds to infrared absorption derived from functional groups. More specifically, the sharp peak near wavenumber 840 ^cm is attributed to CH out-of-plane bending vibration; the sharp peak near wavenumber 1300 ^cm is attributed to epoxy three-membered ring stretching vibration; wavenumber 1700 cm. The sharp peak near ^-1 is attributed to C=O stretching vibration.

Here, in condition (1), in obtaining a spectrum by Fourier transform infrared spectrophotometry, it is necessary to obtain a carbon nanotube dispersion by dispersing the carbon nanotubes so that the bundle length is 10 μm or more. Here, for example, carbon nanotubes, water and a surfactant (for example, sodium dodecylbenzenesulfonate) are blended in an appropriate ratio and stirred for a predetermined period of time using ultrasonic waves or the like, so that the bundle length is reduced in water. A dispersion liquid in which carbon nanotube dispersions having a size of 10 μm or more are dispersed can be obtained.

The bundle length of the carbon nanotube dispersion can be obtained by analyzing with a wet image analysis type particle size measuring device. Such a measuring device calculates the area of each dispersion from the image obtained by photographing the carbon nanotube dispersion, and the diameter of the circle having the calculated area (hereinafter also referred to as the ISO area diameter). can be obtained). In this specification, the bundle length of each dispersion is defined as the value of the ISO circle diameter thus obtained.

-Condition (2)
Condition (2) stipulates that "the maximum peak in the differential pore volume distribution measured for carbon nanotubes is in the range of pore diameters greater than 100 nm and less than 400 nm." The differential pore volume distribution of carbon nanotubes can be obtained from the adsorption isotherm of liquid nitrogen at 77K based on the BJH (Barrett-Joyner-Halenda) method. The BJH method is a measurement method for determining the pore size distribution assuming that the pores are cylindrical.

Here, the value of the differential pore volume at the maximum peak in the differential pore volume distribution of CNT is preferably 2 cm ³ /g or more.

- Condition (3)
Condition (3) stipulates that "at least one peak of the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube exists in the range of 1 μm ^-1 to 100 μm ^-1 ". The sufficiency of such conditions can be determined in the following manner. First, the CNTs to be determined are magnified (e.g., 10,000 times) using an electron microscope (e.g., field emission scanning electron microscope), and a plurality of electron microscope images (e.g., 10 sheets). A plurality of electron microscope images obtained are subjected to fast Fourier transform (FFT) processing to obtain a two-dimensional spatial frequency spectrum. A two-dimensional spatial frequency spectrum obtained for each of a plurality of electron microscope images is binarized to obtain an average value of peak positions appearing on the highest frequency side. If the average value of the obtained peak positions is within the range of 1 μm ⁻¹ or more and 100 μm ⁻¹ or less, it is determined that the condition (3) is satisfied. Here, as the "peak" used in the above determination, a clear peak obtained by executing the isolated point extraction process (that is, the inverse operation of the isolated point removal) is used. Therefore, if a clear peak is not obtained within the range of 1 μm ⁻¹ to 100 μm ⁻¹ when the isolated point extraction process is performed, it is determined that the condition (3) is not satisfied.

Here, it is preferable that the peak of the two-dimensional spatial frequency spectrum exists in the range of 2.5 μm ⁻¹ to 100 μm ⁻¹ .

The carbon nanotube preferably satisfies at least two of the above conditions (1) to (3), and more preferably satisfies all of the conditions (1) to (3).

In addition, the elastomer composition of the present invention usually contains a plurality of carbon nanotubes. In addition, the elastomer composition of the present invention preferably contains carbon nanotubes having from one to five walls as CNTs, and more preferably contains single-walled carbon nanotubes. In addition, the elastomer composition of the present invention more preferably mainly contains single-wall to five-walled carbon nanotubes as CNTs, and more preferably mainly contains single-walled carbon nanotubes.
Here, "mainly containing" a certain CNT means that more than half of the total number of the plurality of carbon nanotubes contained in the elastomer composition is the certain CNT.

In addition, the CNT preferably has a total specific surface area of 600 m ² /g or more, more preferably 800 m ² /g or more, and preferably 2600 m ² /g or less, more preferably 1400 m ² /g or less, according to the BET method. . Furthermore, it is preferable that it is 1300 m ^<2> /g or more in the thing which carried out the opening process. CNTs with a high specific surface area are not excessively CNT bundled. Therefore, the individual CNTs are loosely bound to each other and can be easily dispersed. The total specific surface area of CNT by the BET method can be measured, for example, using a BET specific surface area measuring device conforming to JIS Z8830.

Furthermore, the average outer diameter of CNTs is preferably 0.5 nm or more, more preferably 1.0 nm or more, preferably 15.0 nm or less, and more preferably 10.0 nm or less. , 5.0 nm or less. If the average outer diameter of CNTs is equal to or more than the above lower limit, bundling of CNTs can be reduced, and a high specific surface area can be maintained. If the average outer diameter of CNTs is equal to or less than the above upper limit, the ratio of multilayer CNTs can be reduced, and a high specific surface area can be maintained. Here, the average outer diameter of CNTs can be obtained by measuring the diameter (outer diameter) of 100 randomly selected CNTs using a transmission electron microscope (TEM).

The G/D ratio of CNTs is preferably 1 or more and 50 or less. CNTs with a G/D ratio of less than 1 are considered to have low crystallinity, have a large amount of contamination such as amorphous carbon, and have a large content of multilayer CNTs. Conversely, CNTs with a G/D ratio exceeding 50 have high linearity, tend to form bundles with few gaps, and may have a reduced specific surface area. The G/D ratio is an index commonly used to evaluate the quality of CNTs. Vibrational modes called G band (near 1600 cm ⁻¹ ) and D band (near 1350 cm ⁻¹ ) are observed in the Raman spectrum of CNTs measured by a Raman spectrometer. The G band is a vibrational mode derived from the hexagonal lattice structure of graphite, which is the cylindrical surface of CNT, and the D band is a vibrational mode derived from amorphous sites. Therefore, a CNT with a higher peak intensity ratio (G/D ratio) between the G band and the D band can be evaluated as having higher crystallinity (linearity).

The carbon purity of CNT is preferably 98% by mass or higher, more preferably 99% by mass or higher, and still more preferably 99.9% by mass or higher. If the carbon purity is within the above range, the original properties of CNT can be fully exhibited. Here, the carbon purity of CNTs can be obtained from elemental analysis using fluorescent X-rays, thermogravimetric analysis (TGA), or the like.

In addition, the CNT described above can be produced, for example, using the method described in International Publication No. 2021/172078.

The elastomer composition of the present invention preferably contains 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more of the above-mentioned CNTs per 100 parts by mass of the elastomer. , It is particularly preferable to contain 3 parts by mass or more, preferably 10 parts by mass or less, more preferably 8 parts by mass or less, even more preferably 7 parts by mass or less, and particularly preferably 6 parts by mass or less. When the CNT content in the elastomer composition is within the above range, the molded article obtained from the elastomer composition can further reduce the surface resistivity and further increase the mechanical strength in a high-temperature environment.

<Compound A>
Compound A is not particularly limited as long as it satisfies the conditions regarding the distance of the Hansen Solubility Parameter, which will be described later, and any organic compound can be used.

For example, compound A is preferably a compound having a cyclic hydrocarbon. Since cyclic hydrocarbons have excellent affinity with CNTs, it is presumed that the bulk structure is easily fibrillated. The CNTs can be better dispersed in the elastomer in the molded body obtained.

Here, the cyclic hydrocarbon that compound A may have is not particularly limited, and examples thereof include saturated alicyclic hydrocarbons, unsaturated alicyclic hydrocarbons, and aromatic hydrocarbons. More specifically, includes a benzene ring, a naphthalene ring, and a cyclohexane ring. In addition, the compound A may have one type of cyclic hydrocarbon, or may have two or more types of cyclic hydrocarbons. The cyclic hydrocarbon is preferably an aromatic ring such as a benzene ring or a naphthalene ring, more preferably a benzene ring, from the viewpoint of dispersing the CNTs in the elastomer more favorably.

In addition, as the compound having a cyclic hydrocarbon, an ester compound having a cyclic hydrocarbon (a compound having a cyclic hydrocarbon and an ester group) is preferable from the viewpoint of better dispersing the CNTs in the elastomer in the molded article. , an ester compound having an aromatic ring is more preferred, an ester compound having a benzene ring is still more preferred, and a phenyl ester compound is particularly preferred.
Here, specific examples of the compound having a cyclic hydrocarbon include benzoic acid ester compounds such as methyl p-toluate (methyl 4-methylbenzoate), methyl benzoate, benzyl benzoate, and phenyl benzoate; Alkyl 3-phenylpropionate such as methyl phenylpropionate; ethyl cinnamate;
Among these, benzoic acid ester compounds and phenyl ester compounds such as alkyl 3-phenylpropionate are preferred, and methyl p-toluate is more preferred.
In addition, compound A can be used individually by 1 type or in mixture of 2 or more types.

In addition, compound A preferably has a freezing point of 40° C. or lower, more preferably 35° C. or lower. If the freezing point of compound A is equal to or lower than the above upper limit, it is presumed that the fluidity of compound A is sufficiently ensured and that the inside of the CNT bundle structure is well impregnated. , the CNTs can be well dispersed in the elastomer. The lower limit of the freezing point of compound A is not particularly limited, but is, for example, −100° C. or higher, −50° C. or higher, or 5° C. or higher.

In addition, compound A preferably has a boiling point of 120° C. or higher, more preferably 150° C. or higher, preferably 400° C. or lower, and more preferably 300° C. or lower. If the boiling point of the compound A is at least the above lower limit, the compound A will not be excessively vaporized when obtaining the elastomer composition and the molded article, and in the molded article obtained from the elastomer composition, the CNTs will be well incorporated into the elastomer. can be distributed in Further, if the boiling point of compound A is equal to or less than the above upper limit, compound A can be easily removed when performing the compound A removing step in the method for producing an elastomer composition described later.

Compound A preferably has a molecular weight of 100 or more, more preferably 120 or more, preferably 500 or less, more preferably 400 or less, and even more preferably 300 or less. . If the molecular weight of compound A is within the above range, it is presumed that compound A can easily impregnate the inside of the CNT bundle structure. It can be dispersed well.

Compound A preferably has a vapor pressure of 1.0 kPa or less at 25° C., more preferably 0.1 kPa or less. If the vapor pressure of compound A is 1.0 kPa or less, it is presumed that the fluidity of compound A is sufficiently ensured and impregnation of the inside of the CNT bundle structure is facilitated. The CNTs can be sufficiently well dispersed in the elastomer in the molded body obtained. Although the lower limit of the vapor pressure of compound A is not particularly limited, it is, for example, 10 ⁻⁵ kPa or more.

<<Hansen solubility parameter distance R1>>
Here, the distance R1 (unit: MPa ^1/2 ) of the Hansen solubility parameter between compound A and the CNT described above must be 1.0 MPa ^1/2 or more and 10.0 MPa ^1/2 or less. , preferably 5.0 MPa ^1/2 or less, more preferably 3.0 MPa ^1/2 or less, even more preferably 2.0 MPa ^1/2 or less, and 1.2 MPa ^1/2 or more preferably 1.5 MPa ^1/2 or more. When R1 is within the above range, it is possible to reduce the surface resistivity of a molded article formed using the elastomer composition and improve the mechanical strength in a high-temperature environment.

The "distance R1 (MPa ^1/2 ) of the Hansen solubility parameter between the carbon nanotube and the compound A" can be calculated using the following formula (1).
R1={4×(δ _d3 −δ _d2 ) ² +(δ _p3 −δ _p2 ) ² +(δ _h3 −δ _h2 ) ² } ^1/2 (1)
δ _d2 : Dispersion term of compound A δ _d3 : Dispersion term of carbon nanotube δ _p2 : Polarity term of compound A δ _p3 : Polarity term of carbon nanotube δ _h2 : Hydrogen bond term of compound A δ _h3 : Hydrogen bond term of carbon nanotube

<<Hansen solubility parameter distance R2>>
Moreover, the distance R2 (unit: MPa ^1/2 ) of the Hansen solubility parameter between the compound A and the elastomer described above must be larger than R1 as described above. If R2 is larger than R1, the surface resistivity of the molded article formed using the elastomer composition can be reduced and the mechanical strength under high temperature environments can be improved.

Specifically, R2 is preferably 4.0 MPa ^1/2 or more, more preferably 5.0 MPa ^1/2 or more, and still more preferably 6.0 MPa ^1/2 or more. It is particularly preferably 0 MPa ^1/2 or more, preferably 15.0 MPa ^1/2 or less, and more preferably 10.0 MPa ^1/2 or less. If R2 is within the above range, the surface resistivity of the molded article formed using the elastomer composition can be further reduced and the mechanical strength under high temperature environments can be further improved.

The "distance R2 of the Hansen solubility parameter between the elastomer and the compound A" can be calculated using the following formula (2).
R2={4×(δ _d1 −δ _d2 ) ² +(δ _p1 −δ _p2 ) ² +(δ _h1 −δ _h2 ) ² } ^1/2 (2)
δ _d1 : dispersion term of elastomer δ _d2 : dispersion term of compound A δ _p1 : polar term of elastomer δ _p2 : polar term of compound A δ _h1 : hydrogen bond term of elastomer δ _h2 : hydrogen bond term of compound A

The definition and calculation method of the Hansen solubility parameter are described in the following literature. Charles M. Hansen, "Hansen Solubility Parameters: A Users Handbook," CRC Press, 2007.

For substances whose literature value of Hansen solubility parameter is unknown, the Hansen solubility parameter can be easily estimated from the chemical structure by using computer software (Hansen Solubility Parameters in Practice (HSPiP)).
Specifically, for example, using HSPiP version 3, the values are used for compounds registered in the database, and the estimated values are used for compounds that are not registered.

<<Content>>
The elastomer composition preferably contains 10.0% by mass or less of compound A, more preferably 1.0% by mass or less, even more preferably 0.1% by mass or less, and 0.1% by mass or less. It is particularly preferred to contain less than % by weight. If the content of compound A in the elastomer composition is equal to or less than the above upper limit, the mechanical strength of a molded article formed using the elastomer composition can be further improved in a high-temperature environment. The lower limit of the content of compound A in the elastomer composition is not particularly limited as long as it is higher than the detection limit, but it is preferably 0.01% by mass or more, more preferably 0.05% by mass or more. preferable. If the content of compound A in the elastomer composition is at least the above lower limit, it is possible to easily obtain an elastomer composition in which CNTs are well dispersed.

<Crosslinking agent>
The cross-linking agent that may optionally be included in the elastomer composition of the present invention is not particularly limited, but any known cross-linking agent capable of cross-linking the elastomer in the elastomer composition can be used. Examples of such cross-linking agents include sulfur-based cross-linking agents, peroxide-based cross-linking agents, bisphenol-based cross-linking agents, and diamine-based cross-linking agents.
In addition, a crosslinking agent can be used individually by 1 type or in mixture of 2 or more types.
The content of the cross-linking agent in the elastomer composition is not particularly limited, and may be the amount normally used in known elastomer compositions.

<Additive>
Additives include, but are not limited to, dispersants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, pigments, colorants, foaming agents, antistatic agents, flame retardants, lubricants, and softeners. , tackifiers, plasticizers, release agents, deodorants, fragrances, and the like.
Examples of more specific additives include carbon black, silica, talc, barium sulfate, calcium carbonate, clay, magnesium oxide and calcium hydroxide.
In addition, an additive can be used individually by 1 type or in mixture of 2 or more types.
Moreover, the content of the additive in the elastomer composition is not particularly limited, and may be the amount normally used in known elastomer compositions. For example, the content of the additive in the elastomer composition can be 5 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the elastomer.

(Method for producing elastomer composition)
The elastomer composition of the present invention described above is not particularly limited, and includes a step of mixing CNT and compound A to obtain a mixture containing CNT and compound A (mixing step), a mixture obtained in the mixing step and It can be produced by a method for producing an elastomer composition including a step of subjecting a composition containing an elastomer to dispersion treatment (dispersion step).
The method for producing the elastomer composition may include steps other than the mixing step and the dispersing step described above. For example, after the dispersing step is performed, the cross-linking agent, the additive, and the like may be separately added to perform further dispersing treatment. Moreover, a step of removing compound A from the obtained composition (compound A removing step) may be performed after the dispersing step.

According to the method for producing an elastomer composition, in the dispersing step, the composition containing the elastomer, CNTs and compound A is subjected to dispersion treatment, so that the CNT bundle structure is fibrillated and the elastomer is CNTs can be well dispersed therein. In addition, in the method for producing the elastomer composition described above, since the CNTs and the compound A are mixed in the mixing step before the dispersion step, the CNTs are impregnated with the compound A, and the CNT bundle structure is easily defibrated. During the dispersion treatment in the dispersion step, the CNT bundle structure can be satisfactorily fibrillated, and the CNTs can be further satisfactorily dispersed in the elastomer.

<Mixing process>
In the mixing step, CNT and compound A are mixed to obtain a mixture containing CNT and compound A. In the mixing step, a cross-linking agent and/or an additive may optionally be mixed with the CNTs and the compound A and contained in the mixture, depending on the uses of the elastomer composition and molded article. Moreover, mixing of CNTs and compound A in the mixing step is usually performed in the absence of an elastomer.

Here, the mixing of the CNTs and the compound A is not particularly limited. Any mixing method such as spraying of A can be used. Above all, from the viewpoint of dispersing the CNTs more satisfactorily in the dispersing step, it is preferable to mix the CNTs and the compound A by impregnating the CNTs with the compound A.

The time for which the CNTs are impregnated with the compound A in the mixing step can be any time. 10 hours is more preferred.
The temperature at which the CNTs are impregnated with the compound A is not particularly limited, and can be, for example, a temperature equal to or higher than the freezing point of the compound A and lower than the boiling point.
The impregnation of the CNTs with the compound A is not particularly limited, but is usually performed under normal pressure (1 atm).

<Dispersion process>
In the dispersing step, the composition containing the mixture obtained by mixing the CNTs and the compound A in the mixing step and the elastomer is subjected to a dispersing treatment.
In the mixing step, the composition may optionally contain a cross-linking agent and/or an additive depending on the uses of the elastomer composition and molded article.

Here, the composition to be dispersed in the dispersion step preferably contains 0.1 parts by mass or more, more preferably 1 part by mass or more, and 5 parts by mass of the compound A per 100 parts by mass of the elastomer. More preferably 10 parts by mass or more, preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less. If the content of compound A in the composition is within the above range, the CNTs can be better dispersed in the elastomer.

<< Distributed processing >>
The dispersion treatment is not particularly limited as long as the CNTs can be dispersed in the elastomer, and any known dispersion treatment can be used. Such dispersion treatment includes, for example, dispersion treatment by shear stress, dispersion treatment by collision energy, and dispersion treatment by which a cavitation effect is obtained. According to such distributed processing, the distributed processing can be performed relatively easily.

A two-roll mill, a three-roll mill, or the like can be used as a device that can be used for dispersion treatment by shear stress.
Apparatuses that can be used for dispersion treatment by collision energy include bead mills, rotor/stator type dispersers, and the like.
A jet mill, an ultrasonic disperser, and the like can be used as devices that can be used for the dispersion treatment to obtain the cavitation effect.

The conditions for the dispersion treatment are not particularly limited, and can be set as appropriate within the range of normal dispersion conditions in the apparatus described above, for example.

<Compound A removal step>
In the optional compound A removal step, compound A is removed from the dispersion-treated composition.
Here, the method for removing compound A from the composition is not particularly limited, and includes hot air drying, infrared drying, vacuum drying, and the like.
Then, in the compound A removal step, compound A can be removed from the composition until the amount of compound A in the elastomer composition is the desired amount.

(crosslinked product)
The cross-linked product of the present invention is obtained by cross-linking the elastomer composition containing the above-described cross-linking agent.
The temperature and pressure for cross-linking the elastomer composition are not particularly limited, and can be appropriately set according to the type and amount of the elastomer and cross-linking agent.

(Molded body)
The molded article of the present invention comprises the above-described crosslinked product of the present invention. Specifically, the molded article of the present invention can be obtained by molding and crosslinking the elastomer composition of the present invention described above. Here, the molded article of the present invention is not particularly limited, and examples thereof include belts, hoses, gaskets, packings, and oil seals.
The molded article of the present invention obtained from the elastomer composition of the present invention described above has a low surface resistivity and excellent mechanical strength in a high-temperature environment.
The molding of the elastomer composition is not particularly limited, and can be performed using any molding method such as injection molding, extrusion molding, press molding, and roll molding.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.
In Examples and Comparative Examples, the content of Compound A in the elastomer composition, and the surface resistivity, tensile strength and tensile elongation of the molded article were measured by the following methods.

<Content rate of compound A>
2 g of the elastomer composition (dry rubber) was cut into 5 cm squares and heated at a temperature of 180 ° C. for 1 hour using a constant temperature blower dryer (manufactured by Tokyo Rikakikai Co., Ltd., product name "Constant air blower dryer WFO-420W"). did. The content of compound A (= {(weight of dry rubber before heating - Weight of dry rubber after heating)/Weight of dry rubber before heating}×100%) was obtained.
<Surface resistivity>
Using a resistivity meter (manufactured by Mitsubishi Chemical Analytics, product name “Loresta GX MCP-T700”, probe: LSP), the surface resistivity of the obtained molded article (crosslinked rubber sheet) was measured at 10 different points. The surface resistivity of the crosslinked rubber sheet was taken as the average value of the measured values of 10 points.
<Tensile strength and elongation>
The obtained molded article (crosslinked rubber sheet) was punched into a dumbbell test piece (JIS No. 3) to prepare a test piece. Using a tensile tester (manufactured by Toyo Seiki Co., Ltd., product name "Strograph VG"), in accordance with JIS K6251: 2010, test temperature: 200 ° C., test humidity: 50%, tensile speed: 500 ± 50 mm / min A tensile test was performed under the conditions, and the tensile strength (value obtained by dividing the maximum tensile force (N) recorded when the test piece was pulled until it broke by the initial cross-sectional area (m ² ) of the test piece) and tensile elongation ( The maximum elongation (mm) recorded when the test piece was pulled until it broke was divided by the length (mm) before pulling, and the value multiplied by 100) was measured.

(Example 1)
<Synthesis of CNT>
FIG. 1 shows a schematic configuration of a CNT manufacturing apparatus used for synthesis. A CNT manufacturing apparatus 100 shown in FIG. Synthetic quartz was used as the material of the reaction tube 102 and the dispersion plate 103 .
<<Catalyst carrier forming step>>
The step of forming the catalyst carrier will be described below. Zirconia (zirconium dioxide) beads (ZrO ₂ , volume average particle diameter D50: 350 μm) as a carrier are put into a rotating drum coating device, and while the zirconia beads are stirred (20 rpm), an aluminum-containing solution is sprayed with a spray gun. While spraying (spray amount 3 g/min, spray time 940 seconds, spray air pressure 10 MPa) and drying while supplying compressed air (300 L/min) into the rotating drum, an aluminum-containing coating film was formed on the zirconia beads. . Next, a calcination treatment was performed at 480° C. for 45 minutes to produce primary catalyst particles having an aluminum oxide layer formed thereon. Further, the primary catalyst particles were put into another rotary drum coating device and stirred (20 rpm) while the iron catalyst solution was sprayed with a spray gun (spray amount 2 g / minute, spray time 480 seconds, spray air pressure 5 MPa ) and dried while supplying compressed air (300 L/min) into the rotating drum to form an iron-containing coating film on the primary catalyst particles. Next, a calcination treatment was performed at 220° C. for 20 minutes to produce a catalyst carrier on which an iron oxide layer was further formed.
<<CNT synthesis process>>
300 g of the catalyst carrier produced in this way is put into the reaction tube 102 of the CNT manufacturing apparatus 100, and while the catalyst carrier 107 is fluidized by circulating gas, the formation process, the growth process, and the cooling process are performed in this order. After treatment, a CNT aggregate was produced. The conditions for each step included in the CNT synthesis step were set as follows.
[Formation process]
・Set temperature: 800℃
・Reducing gas: nitrogen 3 sLm, hydrogen 22 sLm
・Processing time: 25 minutes [growth process]
・Set temperature: 800℃
・ Raw material gas: nitrogen 15 sLm, ethylene 5 sLm, carbon dioxide 2 sLm, hydrogen 3 sLm
・Processing time: 10 minutes ・Source gas pyrolysis time: 0.65 seconds [cooling process]
・Cooling temperature: Room temperature ・Purge gas: Nitrogen 25 sLm
<<Separation and recovery process>>
The CNT aggregates synthesized on the catalyst carrier were separated and collected using a forced vortex classifier (rotational speed: 3500 rpm, air volume: 3.5 Nm ³ /min). The recovery rate of CNT aggregates was 99%.
The characteristics of the produced CNT aggregate are tap bulk density: 0.01 g/cm ³ , average CNT length: 200 μm, BET specific surface area: 800 m ² /g, average outer diameter: 4.0 nm, and carbon purity of 99%. there were.
<<Evaluation of CNT>>
When the obtained CNT aggregate was evaluated in the same manner as in Example 1 of WO 2021/172078,
・ In the spectrum obtained by Fourier transform infrared spectroscopic analysis of the carbon nanotube dispersion obtained by dispersing so that the bundle length is 10 μm or more, the peak based on the plasmon resonance of the carbon nanotube dispersion has a wave number of 830 cm ⁻ observed in ¹ ,
(2) For carbon nanotubes, the maximum maximum in the pore distribution curve showing the relationship between the pore diameter and the Log differential pore volume obtained from the adsorption isotherm of liquid nitrogen at 77 K based on the Barrett-Joyner-Halenda method A peak exists within a pore diameter range of more than 100 nm and less than 400 nm,
(3) The peak of the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube was present at the position of 3.0 μm ⁻¹ .
<Preparation of elastomer composition>
After weighing 12.0 g of synthesized carbon nanotubes (Hansen solubility parameters: δ _d3 =18.7, δ _p3 =4.93, δ _h3 =3.08) in a glass bottle with a capacity of 900 mL, p-toluic acid as compound A was added. 120 g of methyl (manufactured by Tokyo Chemical Industry Co., Ltd., Hansen solubility parameters: δ _d2 =19.0, δ _p2 =6.5, δ _h2 =3.8) was added dropwise. Next, the carbon nanotubes were impregnated with methyl p-toluate by standing in an oven at 40° C. for 12 hours to obtain a mixture containing carbon nanotubes and methyl p-toluate.
Next, vinylidene fluoride rubber (FKM) as an elastomer (manufactured by Chemours, product name “Viton GBL600S”, Hansen solubility parameters: δ _d1 =14.7, δ _p1 =9.0, δ _h1 =2.7) 300 g is water-cooled and wound on a 6-inch open roll (two-roll mill) adjusted to a roll gap of 0.5 mm, then the above mixture is added and kneaded for 60 minutes, FKM, carbon nanotubes, and p- A rubber sheet composited with methyl toluate was obtained.
The resulting rubber sheet was vacuum-dried at 180° C. for 24 hours using a vacuum dryer (square constant-temperature vacuum dryer manufactured by Yamato Scientific Co., Ltd.) to obtain a dry rubber (elastomer composition).
Then, the content of compound A in the dry rubber was measured. Table 1 shows the results.
<Preparation of compact>
100 parts by mass of the obtained dried rubber was wound on an open roll, and 3 parts by mass of zinc oxide (zinc white) as a cross-linking aid and triallyl isocyanurate (manufactured by Mitsubishi Chemical Corporation, product name "TAIC M- 60") and 2 parts by mass of 2,5-dimethyl-2,5 di(t-butylperoxy)hexane (manufactured by NOF Corporation, product name "Perhexa 25B40") as a cross-linking agent are added and kneaded, The obtained sheet-like rubber composition was subjected to primary cross-linking at a temperature of 160° C. and a pressure of 10 MPa for 20 minutes. Then, it was heated in a gear oven at 232° C. for 2 hours for secondary cross-linking to obtain a cross-linked rubber sheet (length: 150 mm, width: 150 mm, thickness: 2 mm) as a molding.
Then, the surface resistivity, tensile strength and elongation of the crosslinked rubber sheet were measured. Table 1 shows the results.

(Example 2)
Carbon nanotubes synthesized as follows (Hansen solubility parameters: δ _d3 =18.7, δ _p3 =4.93, δ _h3 =3.08) were used in the same manner as in Example 1. , elastomer compositions and moldings were prepared and evaluated. Table 1 shows the results.
<Synthesis of CNT>
The CNTs were produced by a method of supplying raw material gas while continuously transporting a particulate catalyst carrier by rotating a screw.
FIG. 2 shows a schematic configuration of a CNT aggregate manufacturing apparatus 200 used. A CNT aggregate manufacturing apparatus 200 shown in FIG. 204 , and a gas mixture prevention device 203 for preventing gas from mixing between the formation unit 202 and the growth unit 204 . Furthermore, the CNT aggregate manufacturing apparatus 200 includes an inlet purge device 201 arranged in the front stage of the formation unit 202, an outlet purge device 205 arranged in the rear stage of the growth unit 204, and further arranged in the rear stage of the outlet purge device 205. The cooling unit 206 and other components are provided. The formation unit 202 includes a formation furnace 202a for holding the reducing gas, a reducing gas injection device 202b for injecting the reducing gas, a heating device 202c for heating at least one of the catalyst and the reducing gas, and the gas in the furnace. It is composed of an exhaust device 202d and the like for discharging to the outside of the system. The gas mixture prevention device 203 includes an exhaust device 203a and a purge gas injection device 203b that injects a purge gas (seal gas). The growth unit 204 includes a growth furnace 204a for maintaining the source gas environment, a source gas injection device 204b for injecting the source gas, a heating device 204c for heating at least one of the catalyst and the source gas, An exhaust device 204d or the like for discharging gas to the outside of the system is provided. An inlet purge device 201 is attached to a connecting portion 209 that connects an antechamber 213, which is a component for introducing a substrate 211 into the system via a hopper 212, and a formation furnace 202a. The cooling unit 206 includes a cooling container 206a for holding inert gas, and a water-cooling cooling device 206b arranged so as to surround the inner space of the cooling container 206a. The transport unit 207 is a unit that continuously transports the substrate 211 by screw rotation. It is implemented by a screw vane 207a and a driving device 207b capable of rotating the screw vane to a state in which the substrate conveying capability can be exhibited. The heating device 214 is configured to be able to heat the inside of the system at a temperature lower than the heating temperature in the formation unit, and heats the vicinity of the driving device 207b.
<<catalyst layer forming step>>
Zirconia (zirconium dioxide) beads (ZrO ₂ , volume average particle diameter D50: 650 μm) as a substrate are put into a rotating drum type coating device, and while stirring the zirconia beads (20 rpm), an aluminum-containing solution is sprayed through a spray gun. While spraying (spray amount 3 g / min, spray time 940 seconds, spray air pressure 10 MPa), dry while supplying compressed air (300 L / min) into the rotating drum to form an aluminum-containing coating film on the zirconia beads. did. Next, a calcination treatment was performed at 480° C. for 45 minutes to produce primary catalyst particles having an aluminum oxide layer formed thereon. Further, the primary catalyst particles were put into another rotary drum type coating device and stirred (20 rpm) while the iron catalyst solution was sprayed with a spray gun (spray amount: 2 g/min, spray time: 480 seconds, spray air pressure: 5 MPa). ) and dried while supplying compressed air (300 L/min) into the rotating drum to form an iron-containing coating film on the primary catalyst particles. Next, a sintering treatment was performed at 220° C. for 20 minutes to produce a substrate on which an iron oxide layer was further formed.
<<CNT synthesis process>>
The base material having a catalyst on its surface prepared in this way was put into the feeder hopper of the manufacturing apparatus, and while being conveyed by the screw conveyor, the formation process, the growth process, and the cooling process were performed in order to manufacture a CNT aggregate. .
<< Formation process ~ Cooling process >>
The conditions of the inlet purge device, formation unit, gas contamination prevention device, growth unit, outlet purge device, and cooling unit of the CNT aggregate production apparatus were set as follows, and CNTs were continuously produced.
Feeder hopper ・Feed speed: 1.25 kg/h
・Exhaust volume: 10 sLm (natural exhaust from the gap)
Inlet purge device Purge gas: Nitrogen 40 sLm
Formation unit Furnace temperature: 800°C
・Reducing gas: nitrogen 6 sLm, hydrogen 54 sLm
・Displacement: 60sLm
・Processing time: 20 minutes Gas contamination prevention device ・Purge gas: 20 sLm
・Displacement volume of exhaust system: 62sLm
Growth unit Furnace temperature: 830°C
・ Raw material gas: nitrogen 15 sLm, ethylene 5 sLm, carbon dioxide 1 sLm, hydrogen 3 sLm
・Displacement: 47sLm
・Processing time: 10 minutes Outlet purge device ・Purge gas: Nitrogen 45 sLm
Cooling unit ・Cooling temperature: Room temperature ・Exhaust volume: 10 sLm (natural exhaust from the gap)
<<Separation and recovery process>>
The CNT aggregates synthesized on the base material were separated and recovered using a forced vortex classifier (rotational speed: 2300 rpm, air flow rate: 3.5 Nm ³ /min). The recovery rate of CNT aggregates was 96%.
The characteristics of the produced CNT aggregate are, as typical values, tap bulk density: 0.02 g/cm ³ , average CNT length: 150 μm, BET specific surface area: 900 m ² /g, average outer diameter: 4.0 nm, carbon Purity was 99%.
<<Evaluation of CNT>>
When the obtained aggregate of carbon nanotubes was evaluated in the same manner as in Example 1 of WO 2021/172078,
(1) In the spectrum obtained by Fourier transform infrared spectroscopic analysis of the carbon nanotube dispersion obtained by dispersing it so that the bundle length is 10 μm or more, the peak based on the plasmon resonance of the carbon nanotube dispersion is at the wavenumber Observed at 685 cm ^-1 ,
(2) For carbon nanotubes, the maximum maximum in the pore distribution curve showing the relationship between the pore diameter and the Log differential pore volume obtained from the adsorption isotherm of liquid nitrogen at 77 K based on the Barrett-Joyner-Halenda method A peak exists within a pore diameter range of more than 100 nm and less than 400 nm,
(3) The peak of the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube was present at the position of 2.5 μm ⁻¹ .

(Comparative example 1)
As carbon nanotubes, the product name “ZEONANO SG101” manufactured by Zeon Corporation (average length: 350 μm, BET specific surface area: 1438 m ² /g, G/D ratio: 2.8, Hansen solubility parameter: δ _d3 = 19.4, An elastomer composition and a molded article were prepared and evaluated in the same manner as in Example 1 except that δ _p3 =6.0 and δ _h3 =4.5) were used. Table 1 shows the results.
In addition, when the aggregate of carbon nanotubes (ZEONANO SG101) was evaluated in the same manner as in Example 1 of WO 2021/172078,
(1) In the spectrum obtained by Fourier transform infrared spectroscopic analysis of the carbon nanotube dispersion obtained by dispersing it so that the bundle length is 10 μm or more, the peak based on the plasmon resonance of the carbon nanotube dispersion is at the wavenumber Observed at 214 cm ⁻¹ ,
(2) For carbon nanotubes, the maximum maximum in the pore distribution curve showing the relationship between the pore diameter and the Log differential pore volume obtained from the adsorption isotherm of liquid nitrogen at 77 K based on the Barrett-Joyner-Halenda method The peak does not exist in the pore diameter range of more than 100 nm and less than 400 nm,
(3) The peak of the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube did not exist in the range of 1 μm ⁻¹ to 100 μm ⁻¹ .

(Comparative example 2)
The procedure of Example 1 was repeated except that methyl p-toluate was not used during preparation of the elastomer composition (that is, vinylidene fluoride rubber as an elastomer and carbon nanotubes were kneaded to obtain a rubber sheet). Elastomer compositions and molded articles were prepared and evaluated. Table 1 shows the results.

From Table 1, it can be seen that in Examples 1 and 2, molded articles having low surface resistivity and excellent mechanical strength in a high temperature environment can be obtained. In addition, it can be seen that the molded article of Comparative Example 1, which does not use the prescribed CNTs, has high surface resistivity, and the molded article of Comparative Example 2, which does not contain compound A, has high surface resistivity and low mechanical strength.

ADVANTAGE OF THE INVENTION According to this invention, the elastomer composition which can form the molded object which has a low surface resistivity and is excellent in mechanical strength in a high temperature environment can be provided.
Moreover, according to the present invention, it is possible to provide a crosslinked product and a molded product that have low surface resistivity and excellent mechanical strength in a high-temperature environment.

100 CNT production device 101 heater 102 reaction tube 103 dispersion plate 104 reducing gas/raw material gas introduction port 105 exhaust port 106 gas heating acceleration unit 107 catalyst carrier 200 CNT aggregate production device 201 inlet purge device 202 formation unit 202a formation furnace 202b reduction Gas injection device 202c Heating device 202d Exhaust device 203 Gas mixture prevention device 203a Exhaust device 203b Purge gas injection device 204 Growth unit 204a Growth furnace 204b Source gas injection device 204c Heating device 204d Exhaust device 205 Outlet purge device 206 Cooling unit 206a Cooling container 206b Water cooling Cooling device 207 Conveying unit 207a Screw blade 207b Driving device 208-210 Connecting part 211 Base material 212 Hopper 214 Heating device

Claims (10)

comprising an elastomer, a carbon nanotube, and a compound A;
The distance R1 of the Hansen solubility parameter between the carbon nanotube and the compound A is 1.0 MPa ^1/2 or more and 10.0 MPa ^1/2 or less,
the distance R2 of the Hansen solubility parameter between the elastomer and the compound A is greater than the distance R1,
The elastomer composition, wherein the carbon nanotube satisfies at least one of the following conditions (1) to (3).
(1) The plasmon resonance of the carbon nanotube dispersion in the spectrum obtained by Fourier transform infrared spectroscopic analysis of the carbon nanotube dispersion obtained by dispersing the carbon nanotubes so that the bundle length is 10 μm or more. There is at least one peak based on the wave number in the range of more than 300 cm ⁻¹ to 2000 cm ⁻¹ or less.
(2) For the carbon nanotubes, the maximum in the pore distribution curve showing the relationship between the pore diameter and the Log differential pore volume obtained from the adsorption isotherm of liquid nitrogen at 77 K based on the Barrett-Joyner-Halenda method is in the pore diameter range of more than 100 nm and less than 400 nm.
(3) At least one peak in the two-dimensional spatial frequency spectrum of the electron microscope image of the carbon nanotube exists in the range of 1 μm ⁻¹ to 100 μm ⁻¹ . 2. The elastomer composition according to claim 1, wherein the content of compound A is 10.0% by mass or less. 3. The elastomer composition according to claim 1, wherein said elastomer is at least one selected from the group consisting of fluororubber, hydrogenated nitrile rubber, butadiene rubber and silicone rubber. The elastomer composition according to any one of claims 1 to 3, wherein said compound A is a compound having an aromatic ring. 5. The elastomeric composition of Claim 4, wherein said compound A is a phenyl ester compound. 6. The elastomer composition according to any one of claims 1 to 5, comprising 0.1 parts by mass or more and 10 parts by mass or less of said carbon nanotubes per 100 parts by mass of said elastomer. The elastomeric composition according to any one of claims 1 to 6, wherein said carbon nanotubes are single-walled carbon nanotubes. An elastomeric composition according to any preceding claim, further comprising a cross-linking agent. A crosslinked product obtained by crosslinking the elastomer composition according to claim 8 . A molded article comprising the crosslinked product according to claim 9 .

Images