WO2023090403A1 - Carbon nanotube dispersion, method for producing carbon film, elastomer mixture, method for producing composite material, and method for producing elastomer molded body - Google Patents

Carbon nanotube dispersion, method for producing carbon film, elastomer mixture, method for producing composite material, and method for producing elastomer molded body Download PDF

Info

Publication number
WO2023090403A1
WO2023090403A1 PCT/JP2022/042766 JP2022042766W WO2023090403A1 WO 2023090403 A1 WO2023090403 A1 WO 2023090403A1 JP 2022042766 W JP2022042766 W JP 2022042766W WO 2023090403 A1 WO2023090403 A1 WO 2023090403A1
Authority
WO
WIPO (PCT)
Prior art keywords
dispersion
elastomer
dispersion medium
cnt
film
Prior art date
Application number
PCT/JP2022/042766
Other languages
French (fr)
Japanese (ja)
Inventor
慶久 武山
Original Assignee
日本ゼオン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Publication of WO2023090403A1 publication Critical patent/WO2023090403A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/168—After-treatment
    • C01B32/174—Derivatisation; Solubilisation; Dispersion in solvents
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L101/00—Compositions of unspecified macromolecular compounds

Definitions

  • the present invention relates to a carbon nanotube dispersion, a carbon membrane manufacturing method, an elastomer mixture, a composite material manufacturing method, and an elastomer molding manufacturing method.
  • Carbon nanotubes (hereinafter sometimes abbreviated as "CNT”) have been attracting attention as a material with excellent properties such as electrical conductivity, thermal conductivity, and strength.
  • CNTs are once dispersed in a dispersion medium to prepare a carbon nanotube dispersion.
  • the resulting CNT dispersion is a carbon film formed by aggregating a plurality of CNTs, or an elastomer molded body containing CNTs and an elastomer (hereinafter, the carbon film and the elastomer molded body are collectively referred to as a "molded body"). may be used).
  • Patent Document 1 when preparing a CNT dispersion, by using a solvent in which the polar term, the dispersion term, and the hydrogen bonding term of the Hansen solubility parameter are within predetermined ranges as a dispersion medium, Techniques for stably dispersing CNTs and obtaining a CNT composite film that maintains the properties of CNTs have been proposed.
  • the above-described conventional CNT dispersion has room for improvement in terms of increasing the electrical conductivity of the molded article obtained using the CNT dispersion.
  • an object of the present invention is to provide a carbon nanotube dispersion capable of forming a molded article having excellent conductivity. Another object of the present invention is to provide a method for producing a carbon film having excellent conductivity. It is another object of the present invention to provide an elastomer mixed liquid, a method for producing a composite material, and a method for producing an elastomer molded article, which can be used to produce an elastomer molded article having excellent conductivity.
  • the inventor of the present invention has made intensive studies in order to achieve the above object.
  • the present inventor focused on the polar terms of the Hansen solubility parameters of the CNTs and the dispersion medium.
  • a CNT dispersion liquid in which the absolute value of the difference between the polar term ⁇ p1 of the CNT and the polar term ⁇ p2 of the dispersion medium (hereinafter sometimes referred to as
  • ) is a predetermined value or less.
  • an object of the present invention is to advantageously solve the above problems.
  • the carbon nanotube dispersion liquid of the following [1] to [5] and the carbon film of the following [6] Provided are a production method, an elastomer mixed solution of [7] below, a method of producing a composite material of [8] below, and a method of producing an elastomer molding of [9] below.
  • a carbon nanotube dispersion containing carbon nanotubes and a dispersion medium wherein the polar term ⁇ p1 of the Hansen solubility parameter HSP c of the carbon nanotube and the polar term ⁇ p2 of the Hansen solubility parameter HSP d of the dispersion medium
  • the absolute value of the difference between the carbon nanotube dispersions is 2.5 MPa 1/2 or less.
  • a method for producing a carbon film comprising the step of forming a film by removing the dispersion medium from the carbon nanotube dispersion according to any one of [1] to [5] above.
  • a carbon film formed from any of the CNT dispersions described above has excellent conductivity.
  • An elastomer mixed liquid containing the carbon nanotube dispersion liquid according to any one of [1] to [5] above and an elastomer By using an elastomer mixture obtained by mixing any of the CNT dispersions described above and an elastomer, an elastomer molded article having excellent conductivity can be produced.
  • a method for producing a composite material comprising the step of removing the dispersion medium from the elastomer mixed liquid described in [7] above.
  • the "Hansen solubility parameter of carbon nanotubes (HSP c )" is composed of the polar term ⁇ p1 , the dispersion term ⁇ d1 and the hydrogen bonding term ⁇ h1
  • the "Hansen solubility parameter of the dispersion medium (HSP d )" is composed of a polar term ⁇ p2 , a dispersion term ⁇ d2 and a hydrogen bonding term ⁇ h2 .
  • ⁇ p1 ”, “ ⁇ d1 ” and “ ⁇ h1 ”, and “ ⁇ p2 ”, “ ⁇ d2 ” and “ ⁇ h2 ” are specified using the method described in the examples. can be done.
  • the carbon nanotube dispersion liquid which can form the molded object excellent in electroconductivity can be provided.
  • the CNT dispersion of the present invention can be used to produce molded articles such as carbon films and elastomer molded articles.
  • the method for producing a carbon membrane of the present invention is a method of producing a carbon membrane using the CNT dispersion of the present invention.
  • the elastomer mixed liquid of the present invention contains the CNT dispersion of the present invention and an elastomer, and can be used for producing composite materials and elastomer moldings.
  • a method for producing a composite material of the present invention is a method of producing a composite material using the elastomer mixture of the present invention.
  • the method for producing an elastomer molded article of the present invention is a method of producing an elastomer molded article using the elastomer mixed liquid of the present invention.
  • the CNT dispersion of the present invention contains CNTs and a dispersion medium, and may optionally contain components (other components) other than the CNTs and the dispersion medium.
  • the absolute value of the difference between the polar term ⁇ p1 of the Hansen solubility parameter HSP c of the CNT and the polar term ⁇ p2 of the Hansen solubility parameter HSP d of the dispersion medium is 2.5 MPa 1/
  • One of the major features is that it is 2 or less.
  • the molded article obtained using the CNT dispersion of the present invention the number of CNT bundle structures is suppressed as compared with the case of using a conventional CNT dispersion, and the molded article is electrically conductive.
  • Other properties of CNTs thermal conductivity, strength, etc.
  • the molded article obtained using the CNT dispersion of the present invention can be used not only for applications requiring electrical conductivity but also for any application requiring other properties of CNTs.
  • HSP c HSP c is composed of three terms, the polar term ⁇ p1 , the dispersion term ⁇ d1 and the hydrogen bonding term ⁇ h1 , as described above.
  • the polarity term ⁇ p1 is not particularly limited, it is preferably 2.0 MPa 1/2 or more, more preferably 3.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body. It is more preferably 4.0 MPa 1/2 or more, particularly preferably 5.5 MPa 1/2 or more, preferably 15.0 MPa 1/2 or less, and 13.0 MPa 1/2 or less. is more preferably 11.0 MPa 1/2 or less.
  • the dispersion term ⁇ d1 is not particularly limited, it is preferably 13.0 MPa 1/2 or more, more preferably 15.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body.
  • the hydrogen bond term ⁇ h1 is not particularly limited, but is preferably 1.0 MPa 1/2 or more, more preferably 2.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body. , More preferably 3.0 MPa 1/2 or more, preferably 12.0 MPa 1/2 or less, more preferably 10.0 MPa 1/2 or less, and 7.0 MPa 1/2 or less It is even more preferable to have
  • the Hansen solubility parameter (HSP c ) of CNTs is thought to be affected by the diameter of CNTs, the amount of defects on the surface of CNTs, and the amount of functional groups. can be adjusted by
  • CNTs are not particularly limited, and single-walled carbon nanotubes and/or multi-walled carbon nanotubes can be used.
  • CNTs are preferably single-walled to five-walled carbon nanotubes. is more preferable. This is because if single-walled CNTs are used, the electrical conductivity of the compact is sufficiently improved even if the blending amount is small.
  • the CNT dispersion liquid of the present invention usually contains a plurality of CNTs.
  • the CNT dispersion of the present invention preferably contains single-walled to five-walled CNTs, more preferably single-walled CNTs.
  • the CNT dispersion of the present invention more preferably mainly contains single-walled to five-walled CNTs, and more preferably mainly single-walled CNTs.
  • “mainly containing” a certain CNT means that more than half of the total number of the plurality of CNTs contained in the CNT dispersion is the certain CNT.
  • the average diameter of CNTs is preferably 1 nm or more, preferably 60 nm or less, more preferably 30 nm or less, and even more preferably 10 nm or less.
  • the average diameter of CNTs is the arithmetic mean value of the diameters (outer diameters) of 20 randomly selected CNTs measured on a transmission electron microscope (TEM) image. can be obtained as
  • the ratio (3 ⁇ ) of the value (3 ⁇ ) obtained by multiplying the standard deviation of the diameter ( ⁇ : sample standard deviation) by 3 to the average diameter (Av) is more than 0.20 and less than 0.80. It is preferable to use CNTs, more preferably 3 ⁇ /Av is more than 0.20 and less than 0.60, more preferably 3 ⁇ /Av is more than 0.25, and 3 ⁇ /Av is 0 It is particularly preferred to use CNTs greater than 0.50. Using CNTs with a 3 ⁇ /Av of more than 0.20 and less than 0.80 can further improve the electrical conductivity of the compact.
  • the average diameter (Av) and standard deviation ( ⁇ ) of CNTs may be adjusted by changing the CNT manufacturing method or manufacturing conditions, or by combining multiple types of CNTs obtained by different manufacturing methods. You may
  • the diameter measured as described above is plotted on the horizontal axis and the frequency is plotted on the vertical axis, and when Gaussian approximation is performed, a normal distribution is usually used.
  • the average length of the CNTs is preferably 10 ⁇ m or more, more preferably 50 ⁇ m or more, even more preferably 80 ⁇ m or more, preferably 600 ⁇ m or less, and preferably 550 ⁇ m or less. More preferably, it is 500 ⁇ m or less.
  • the "average length" of CNTs is obtained by measuring the length of 20 randomly selected CNTs on a scanning electron microscope (SEM) image and calculating the arithmetic mean of the measured values. be able to.
  • CNTs usually have an aspect ratio of more than 10.
  • the aspect ratio of CNTs is determined by measuring the diameter and length of 20 randomly selected CNTs using a scanning electron microscope or transmission electron microscope, and measuring the ratio of the diameter to the length (length/diameter). It can be obtained by calculating the average value.
  • the CNT preferably has a BET specific surface area of 300 m 2 /g or more, more preferably 400 m 2 /g or more, preferably 2000 m 2 /g or less, and 1800 m 2 /g or less. It is more preferably 1600 m 2 /g or less. If the BET specific surface area of CNTs is 300 m 2 /g or more, the electrical conductivity of the compact can be sufficiently increased with a small amount. Further, when the BET specific surface area of the CNTs is 2000 m 2 /g or less, the CNT bundle structure can be defibrated satisfactorily and the electrical conductivity of the compact can be further improved.
  • the term "BET specific surface area” refers to the nitrogen adsorption specific surface area measured using the BET method.
  • CNTs preferably show an upward convex shape in the t-plot obtained from the adsorption isotherm.
  • the "t-plot" can be obtained by converting the relative pressure to the average thickness t (nm) of the nitrogen gas adsorption layer in the CNT adsorption isotherm measured by the nitrogen gas adsorption method. That is, the average thickness t of the nitrogen gas adsorption layer corresponding to the relative pressure is obtained from a known standard isotherm obtained by plotting the average thickness t of the nitrogen gas adsorption layer against the relative pressure P/P0, and the above conversion is performed. gives a t-plot of CNTs (t-plot method by de Boer et al.). It should be noted that CNTs exhibiting a convex shape in the t-plot obtained from the adsorption isotherm are preferably CNTs that have not undergone opening treatment.
  • the growth of a nitrogen gas adsorption layer on a substance having pores on its surface is classified into the following processes (1) to (3). Then, the slope of the t-plot changes due to the following processes (1) to (3).
  • the t-plot showing an upwardly convex shape is located on a straight line passing through the origin in a region where the average thickness t of the nitrogen gas adsorption layer is small, whereas when t becomes large, the plot is on the straight line.
  • position shifted downward from A CNT having such a t-plot shape has a large ratio of the internal specific surface area to the total specific surface area of the CNT, indicating that many openings are formed in the CNT.
  • the inflection point of the t-plot of CNT is preferably in the range that satisfies 0.2 ⁇ t (nm) ⁇ 1.5, and is in the range of 0.45 ⁇ t (nm) ⁇ 1.5. is more preferable, and it is even more preferable to be in the range of 0.55 ⁇ t(nm) ⁇ 1.0. If the inflection point of the t-plot of CNT is within this range, it is possible to improve the properties (eg electrical conductivity, thermal conductivity, strength, etc.) of the molded product with a small amount.
  • the "position of the bending point" is the intersection of the approximate straight line A in the process (1) described above and the approximate straight line B in the process (3) described above.
  • the CNT preferably has a ratio (S2/S1) of internal specific surface area S2 to total specific surface area S1 obtained from t-plot of 0.05 or more and 0.30 or less. If the S2/S1 value of CNT is within such a range, the electrical conductivity of the molded article can be sufficiently enhanced with a small compounding amount.
  • the total specific surface area S1 and the internal specific surface area S2 of CNT can be obtained from the t-plot. Specifically, first, the total specific surface area S1 can be obtained from the slope of the approximate straight line in process (1), and the external specific surface area S3 can be obtained from the slope of the approximate straight line in process (3). By subtracting the external specific surface area S3 from the total specific surface area S1, the internal specific surface area S2 can be calculated.
  • the measurement of the adsorption isotherm of CNT, the creation of the t-plot, and the calculation of the total specific surface area S1 and the internal specific surface area S2 based on the analysis of the t-plot can be performed, for example, by a commercially available measurement device "BELSORP ( (registered trademark)-mini” (manufactured by Nippon Bell Co., Ltd.).
  • CNTs preferably have a Radial Breathing Mode (RBM) peak when evaluated using Raman spectroscopy.
  • RBM Radial Breathing Mode
  • RBM does not exist in the Raman spectrum of multilayer CNTs having three or more layers.
  • the CNT preferably has a ratio of G-band peak intensity to D-band peak intensity (G/D ratio) in the Raman spectrum of 0.5 or more and 5.0 or less. If the G/D ratio is 0.5 or more and 5.0 or less, the electrical conductivity of the molded article can be further improved.
  • the G/D ratio is measured using a microlaser Raman spectrophotometer (Nicolet Almega XR manufactured by Thermo Fisher Scientific Co., Ltd.), and the obtained Raman spectrum is 1590 cm ⁇ It can be calculated by obtaining the intensity of the G band peak observed near 1 and the intensity of the D band peak observed near 1340 cm ⁇ 1 .
  • CNTs can be produced by known CNT synthesis methods such as an arc discharge method, a laser ablation method, and a chemical vapor deposition method (CVD method), without any particular limitation.
  • CNTs are synthesized, for example, by supplying a raw material compound and a carrier gas onto a substrate having a catalyst layer for CNT production on its surface, and synthesizing CNTs by chemical vapor deposition (CVD).
  • CVD chemical vapor deposition
  • the CNT obtained by the super-growth method may be referred to as "SGCNT".
  • the CNTs produced by the super-growth method may consist only of SGCNTs, or may contain other carbon nanostructures such as non-cylindrical carbon nanostructures in addition to SGCNTs. good.
  • the concentration (content ratio) of CNTs in the CNT dispersion of the present invention is preferably 0.01% by mass or more, and preferably 0.03% by mass or more, with the mass of the CNT dispersion being 100% by mass. It is more preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less. If the CNT concentration in the CNT dispersion is within the range described above, the electrical conductivity of the compact can be further improved.
  • ⁇ Dispersion medium> In the dispersion medium contained in the CNT dispersion of the present invention, the value of
  • Any dispersion medium can be used without any particular limitation as long as it is 2.5 MPa 1/2 or less.
  • HSP d HSP d is composed of three terms, the polar term ⁇ p2 , the dispersion term ⁇ d2 and the hydrogen bonding term ⁇ h2 , as described above.
  • the polar term ⁇ p2 is not particularly limited, but is preferably 3.0 MPa 1/2 or more, more preferably 4.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body. It is more preferably 5.0 MPa 1/2 or more, particularly preferably 6.2 MPa 1/2 or more, preferably 14.0 MPa 1/2 or less, and 12.0 MPa 1/2 or less. is more preferable, and 10.0 MPa 1/2 or less is even more preferable.
  • the dispersion term ⁇ d2 is not particularly limited, it is preferably 13.0 MPa 1/2 or more, more preferably 15.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body.
  • the hydrogen bonding term ⁇ h2 is not particularly limited, but from the viewpoint of further improving the conductivity of the molded body, it is preferably 1.0 MPa 1/2 or more, more preferably 2.0 MPa 1/2 or more. , More preferably 2.5 MPa 1/2 or more, preferably less than 9.0 MPa 1/2 , more preferably 7.0 MPa 1/2 or less, and 5.0 MPa 1/2 or less It is even more preferable to have
  • the Hansen solubility parameter (HSP d ) of the dispersion medium can be adjusted by changing the type of dispersion medium.
  • HSP d Hansen solubility parameter
  • an organic solvent is preferably used, and specifically, acetophenone, p-chlorotoluene, methyl ethyl ketone, and cyclohexanone (these are sometimes collectively referred to as "the above four organic solvents"). is preferred, and acetophenone and p-chlorotoluene are more preferred.
  • a dispersion medium may be used individually by 1 type, and may be used in combination of 2 or more types.
  • the CNT dispersion of the present invention may contain, as a dispersion medium, only one type selected from the group consisting of the four types of organic solvents described above, or may contain only one selected from the group consisting of the four types of organic solvents described above. It may contain two or more kinds.
  • the CNT dispersion of the present invention as a dispersion medium, at least one selected from the group consisting of the above four organic solvents, an organic solvent other than the above four organic solvents, and water. and at least one of the above may be included.
  • the content of the dispersion medium in the CNT dispersion of the present invention is preferably 95% by mass or more, more preferably 97% by mass or more, more preferably 99% by mass, with the mass of the CNT dispersion being 100% by mass. It is more preferably 99.5% by mass or more, particularly preferably 99.5% by mass or more, preferably 99.99% by mass or less, and more preferably 99.97% by mass or less. If the content of the dispersion medium in the CNT dispersion is within the range described above, the electrical conductivity of the compact can be further improved.
  • the components that the CNT dispersion may contain include dispersants and other known additives other than elastomers that can be used in the preparation of composite materials and moldings.
  • another component may be used individually by 1 type, and may be used in combination of 2 or more type.
  • the content of other components in the CNT dispersion is set to 10%, where the mass of the CNT dispersion is 100% by mass. It is preferably no more than 5% by mass, more preferably no more than 5% by mass, even more preferably no more than 1% by mass, particularly preferably no more than 0.1% by mass, and no more than 0.01% by mass. is most preferred.
  • the absolute value of the difference between the polar term ⁇ p1 of the Hansen solubility parameter HSP c of the CNT and the polar term ⁇ p2 of the Hansen solubility parameter HSP d of the dispersion medium is 2. .5 MPa 1/2 or less, preferably 2.0 MPa 1/2 or less, more preferably 1.7 MPa 1/2 or less, and 1.5 MPa 1/2 or less is more preferably 1.1 MPa 1/2 or less, and particularly preferably 0.8 MPa 1/2 or less.
  • the distance Ra of the Hansen solubility parameter between the carbon nanotube and the dispersion medium is preferably 4.0 MPa 1/2 or less, more preferably 3.5 MPa 1/2 or less. It is more preferably 3.0 MPa 1/2 or less, even more preferably 2.5 MPa 1/2 or less, and particularly preferably 2.0 MPa 1/2 or less. If the distance R a of the Hansen solubility parameter is 4.0 MPa 1/2 or less, it is presumed that the effect of improving the dispersibility of CNTs is further enhanced, and the electrical conductivity of the compact can be further improved.
  • the lower limit of the distance Ra is not particularly limited as long as it is 0 MPa 1/2 or more.
  • a CNT dispersion can be prepared by dispersing CNTs and other optional components in a dispersion medium using a known dispersion process.
  • dispersion treatment for example, ultrasonic treatment can be preferably used.
  • Dispersion conditions (dispersion time, etc.) for distributed processing can be set as appropriate.
  • the method for producing a carbon film of the present invention includes a step of forming a film by removing the dispersion medium from the CNT dispersion of the present invention described above (film forming step).
  • a carbon film formed from the CNT dispersion of the present invention has excellent conductivity.
  • the dispersion medium does not necessarily have to be completely removed from the carbon film, and the dispersion medium may remain in an amount within a range that does not excessively adversely affect the desired properties of the carbon film.
  • the method for producing a carbon film of the present invention may include steps other than the film forming step.
  • the dispersion medium is removed from the CNT dispersion using, for example, one of the following methods (A) and (B).
  • A) A method of applying a CNT dispersion onto a film-forming substrate and then drying the applied CNT dispersion.
  • B) A method of filtering a CNT dispersion liquid using a porous film-forming base material and drying the resulting filtrate.
  • the film-forming substrate is not particularly limited, and known substrates, such as resin substrates and glass substrates, can be used depending on the application of the carbon film to be produced.
  • resin base materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene (PTFE), polyimide, polyphenylene sulfide, aramid, polypropylene, polyethylene, polylactic acid, polyvinyl chloride, polycarbonate, and polymethacrylic acid.
  • Substrates made of methyl, alicyclic acrylic resins, cycloolefin resins, triacetyl cellulose and the like can be mentioned.
  • glass substrates include substrates made of soda glass.
  • the porous film-forming substrate for filtering the CNT dispersion in the above method (B) include filter paper and porous sheets made of cellulose, nitrocellulose, alumina, or the like.
  • the coating method includes a dipping method, a roll coating method, a gravure coating method, a knife coating method, an air knife coating method, a roll knife coating method, a die coating method, a screen printing method, a spray coating method, a gravure offset method, and the like. can be used.
  • ⁇ Filtration>> As a method for filtering the CNT dispersion liquid using the film-forming substrate in the above method (B), a known filtration method can be employed. Specifically, natural filtration, vacuum filtration, pressure filtration, centrifugal filtration, etc. can be used as the filtration method.
  • ⁇ Dry>> As the method for drying the CNT dispersion applied onto the film-forming substrate in the above method (A) and the method for drying the filtrate obtained in the above method (B), known drying methods can be employed. Examples of the drying method include hot air drying, vacuum drying, hot roll drying, and infrared irradiation.
  • the drying temperature is not particularly limited, but usually room temperature to 200° C., and the drying time is not particularly limited, but is usually 0.1 to 150 minutes.
  • steps optionally included in the method for producing a carbon film of the present invention are not particularly limited, but include, for example, a step of press processing the formed carbon film to increase its density (press step).
  • the elastomer mixture of the present invention contains an elastomer and the CNT dispersion of the present invention described above.
  • the elastomer mixture of the present invention contains at least the elastomer, the CNTs described above, and the liquid medium containing the dispersion medium described above, and optionally components other than the elastomer, CNTs, and the liquid medium (other components )including.
  • the elastomer contained in the elastomer mixture is not particularly limited, and any rubber, resin, or mixture thereof can be used, for example.
  • 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;
  • 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.
  • the type of elastomer may be appropriately selected according to the application of the elastomer molded article obtained using the elastomer mixture.
  • an elastomer may be used individually by 1 type, and may be used in combination of 2 or more type.
  • the ratio of the elastomer to CNTs in the elastomer mixed solution is not particularly limited, but the content of CNTs in the mixed solution is preferably 0.1 parts by mass or more, and 1 part by mass or more per 100 parts by mass of the elastomer. more preferably 2 parts by mass or more, preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7 parts by mass or less. If the content of CNTs in the elastomer mixed solution is within the above range, the electrical conductivity of the obtained elastomer molding can be sufficiently improved.
  • the CNTs contained in the elastomer mixture were those contained in the CNT dispersion of the present invention described above.
  • the liquid medium contained in the elastomer mixture contains at least the dispersion medium contained in the CNT dispersion of the present invention described above.
  • the liquid medium may include water or organic solvents not derived from the CNT dispersion (eg, the organic solvent used to dissolve the elastomer prior to mixing the CNT dispersion with the elastomer).
  • the components that the elastomer mixture may contain include known additives used in the preparation of elastomer moldings.
  • another component may be used individually by 1 type, and may be used in combination of 2 or more type.
  • the elastomer mixture can be prepared by mixing the CNT dispersion and the elastomer by a known mixing method. Mixing conditions (mixing time, etc.) can be appropriately set.
  • the elastomer is preferably dissolved in a known organic solvent and then mixed with the CNT dispersion.
  • the organic solvent used for dissolving the elastomer can be appropriately selected according to the type of elastomer.
  • the manufacturing method of the composite material of the present invention includes a step of removing the dispersion medium from the elastomer mixed liquid of the present invention (dispersion medium removal step).
  • CNTs can be well dispersed in the elastomer, and the use of the composite material makes it possible to obtain an elastomer molded article having excellent conductivity.
  • the composite material does not necessarily have to have all the dispersion medium removed, and the dispersion medium may remain in an amount within a range that does not excessively adversely affect the desired properties of the composite material.
  • the manufacturing method of the composite material of the present invention may include steps (other steps) other than the dispersion medium removing step.
  • the method for removing the dispersion medium from the elastomer mixture is not particularly limited, and known methods can be used.
  • the dispersion medium can be removed by applying the elastomer mixed liquid onto the film-forming substrate and then drying the applied elastomer mixed liquid.
  • the film-forming substrate and the method of coating and drying used in this method can be the same as the method (A) described above in the section “Method for producing carbon film”.
  • the resulting composite material may be formed into a desired shape such as a sheet.
  • the composite material obtained by the method for producing a composite material of the present invention can be used as it is as an elastomer molding.
  • the elastomer mixture contains water and/or organic solvent other than the dispersion medium derived from the CNT dispersion, it is preferable to remove the water and/or organic solvent in the dispersion medium removal step.
  • These water and/or organic solvents like the dispersion medium, do not need to be completely removed in the composite material obtained, and remain in an amount within a range that does not excessively adversely affect the desired properties of the composite material. You may have
  • steps optionally included in the method for producing a composite material of the present invention are not particularly limited, but include, for example, a step of adding an additive to the composite material obtained through the dispersion medium removal step.
  • a cross-linking agent described later is used as an additive, a composite material (crosslinkable composite material) containing the cross-linking agent can be obtained.
  • the method for producing an elastomer molded article of the present invention includes a step of removing the dispersion medium from the elastomer mixture of the present invention to obtain a composite material (dispersion medium removal step), and a composite material obtained through the dispersion medium removal step. and a step of cross-linking the cross-linkable composite material obtained through the cross-linking agent addition step to obtain an elastomer molded product (cross-linking step).
  • the CNTs can be satisfactorily dispersed in the crosslinked elastomer matrix, and excellent electrical conductivity can be exhibited.
  • the composite material and the elastomer molded article must be completely free of the dispersion medium (and, if necessary, the water and/or organic solvent other than the dispersion medium derived from the CNT dispersion, which are contained in the elastomer mixed liquid). However, it may remain in an amount that does not unduly adversely affect the intended properties of the composite material and elastomeric molded article.
  • the method for producing an elastomer molded article of the present invention may include steps (other steps) other than the dispersion medium removal step, the cross-linking agent addition step, and the cross-linking step. Such other steps are not particularly limited, and any steps for obtaining the desired elastomer molded article can be adopted.
  • Dispersion medium removal step In the dispersion medium removal step, in the same manner as in the dispersion medium removal step described above in the section "Manufacturing method of composite material", the dispersion medium is removed from the elastomer mixture (and, if necessary, the CNT dispersion contained in the elastomer mixture) Water and/or organic solvent other than the dispersion medium) are removed to obtain a composite material.
  • a cross-linking agent is added to the composite material obtained in the dispersion medium removing step.
  • a cross-linking agent a known cross-linking agent capable of cross-linking the elastomer 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.
  • a crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more type.
  • the amount of the cross-linking agent added to the composite material is not particularly limited, and can be appropriately set according to the types of the elastomer and the cross-linking agent.
  • the method of adding the cross-linking agent to the composite material is not particularly limited. For example, by kneading the composite material and the cross-linking agent using a known kneading method, it is possible to obtain a cross-linkable composite material in which the elastomer, CNTs and the cross-linking agent are well mixed.
  • the cross-linkable composite material (composite material containing the cross-linking agent) obtained in the cross-linking agent addition step is cross-linked.
  • the conditions for crosslinking the crosslinkable composite material can be appropriately set according to the type and/or content of the elastomer and crosslinking agent contained in the crosslinkable composite material.
  • the crosslinkable composite material may be placed in a mold having a desired shape in advance and then crosslinked, and when the crosslinking reaction is completed, an elastomer molded body having the desired shape may be obtained.
  • the crosslinked product obtained after the step is completed may be molded into a desired shape by any method to obtain an elastomer molded product.
  • HSP c of carbon nanotubes For the Hansen solubility parameter (HSP c ) of carbon nanotubes, the Hansen sphere method was used to obtain the polar term ⁇ p1 , the dispersion term ⁇ d1 , and the hydrogen bonding term ⁇ h1 . Specifically, 0.003 g of the target carbon nanotube is mixed with 5.997 g of a solvent with a known solubility parameter, and a desktop ultrasonic cleaner (manufactured by Branson, product name “Bransonic 5510”) is used. , sonicated for 25 minutes.
  • a desktop ultrasonic cleaner manufactured by Branson, product name “Bransonic 5510”
  • the resulting carbon nanotube dispersion was centrifuged at 9200 rpm for 5 minutes using a centrifuge (manufactured by Funakoshi Co., Ltd., product name “Argos flaxifuge”), and it was visually determined whether the supernatant solution was colored. . If it was colored, it was determined to be a soluble solvent, and if it was not colored (that is, the color did not change from that of the solvent alone), it was determined to be a non-dissolving solvent.
  • the results of the solubility test are then plotted in the three-dimensional space of the solubility parameters ( ⁇ p , ⁇ d , ⁇ h ) by using computer software (Hansen Solubility Parameters in Practice (HSPiP)) and the coordinates of the dissolving solvent A sphere (Hansen sphere) containing the coordinates of the undissolved solvent was determined. The central coordinates of this sphere were taken as the Hansen solubility parameters HSP c ( ⁇ p1 , ⁇ d1 , ⁇ h1 ) of carbon nanotubes. The solvents were selected so that the number of soluble solvents was 4 or more, and the total number of soluble and insoluble solvents was 20 or more.
  • HSP d of dispersion medium Regarding the Hansen Solubility Parameter (HSP d ) of the dispersion medium, the polar term ⁇ p2 , the dispersion term ⁇ d2 , and the hydrogen bonding term ⁇ h2 were specified by the definition and calculation method described in the following literature. Charles M. Hansen, "Hansen Solubility Parameters: A Users Handbook," CRC Press, 2007. For substances with unknown literature values for Hansen Solubility Parameters, the Hansen Solubility Parameters can be easily estimated from the chemical structure by using computer software (Hansen Solubility Parameters in Practice (HSPiP)).
  • the values may be used for compounds registered in the database, and the estimated values may be used for compounds not registered.
  • the polar term, dispersion term, and hydrogen bonding term of each component are calculated in consideration of the mixing ratio of each component. Taking a weighted average, these values can be used as the polar term ⁇ p2 , the dispersion term ⁇ d2 , and the hydrogen bonding term ⁇ h2 of the dispersion medium.
  • volume resistivity of the obtained molded body was measured as 5. Measured by changing points and measuring points. Then, an average value was obtained from the measured values at five points, and the average value was taken as the volume resistivity of the molded body. It can be said that the smaller the value of the volume resistivity, the better the electrical conductivity of the molded article.
  • a CNT dispersion was obtained by performing irradiation for 25 minutes at .
  • the resulting CNT dispersion was applied onto a film-forming substrate.
  • the coating film on the film forming substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate.
  • the carbon film was peeled off from the film forming substrate to obtain a carbon film having a thickness of 23 ⁇ m.
  • the volume resistivity of the obtained carbon film was measured. Further, the measured value of the volume resistivity was converted into an index value with the volume resistivity of the carbon film obtained in Comparative Example 1 described later as 100 (reference value).
  • a dispersion was obtained.
  • the resulting CNT dispersion was applied onto a film-forming substrate.
  • the coating film on the film forming substrate was dried at a temperature of 180° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate.
  • the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 22 ⁇ m.
  • the volume resistivity of the obtained carbon film was measured. Further, the measured value of the volume resistivity was converted into an index value with the volume resistivity of the carbon film obtained in Comparative Example 4 described later as 100 (reference value).
  • Example 3 A CNT dispersion was obtained in the same manner as in Example 2, except that methyl ethyl ketone was used as the dispersion medium instead of acetophenone. Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 60° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 40 ⁇ m. Various evaluations and measurements were performed in the same manner as in Example 2. Table 2 shows the results.
  • Example 3 A CNT dispersion was obtained in the same manner as in Example 2, except that 1,2,4-trimethylbenzene was used as the dispersion medium instead of acetophenone. Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film forming substrate to obtain a carbon film having a thickness of 53 ⁇ m. Various evaluations and measurements were performed in the same manner as in Example 2. Table 2 shows the results.
  • Example 4 A CNT dispersion was obtained in the same manner as in Example 2, except that p-chlorotoluene was used as the dispersion medium instead of acetophenone. Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 64 ⁇ m. Various evaluations and measurements were performed in the same manner as in Example 2. Table 2 shows the results.
  • a CNT dispersion was obtained by performing irradiation for 25 minutes at an output of 300 W and a frequency of 20000 kHz. Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 180° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 22 ⁇ m. The volume resistivity of the obtained carbon film was measured.
  • Example 6 A CNT dispersion was obtained in the same manner as in Example 5, except that p-chlorotoluene was used as the dispersion medium instead of acetophenone. Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the base film-forming substrate to obtain a carbon film having a thickness of 13 ⁇ m. Various evaluations and measurements were performed in the same manner as in Example 5. Table 3 shows the results.
  • Example 5 A CNT dispersion and a carbon film were obtained in the same manner as in Example 5, except that 1,2,4-trimethylbenzene was used as the dispersion medium instead of acetophenone. Various evaluations and measurements were performed in the same manner as in Example 5. Table 3 shows the results.
  • Example 7 A CNT dispersion was prepared in the same manner as in Example 1 of Experiment A. Separately, 0.075 g of FKM (vinylidene fluoride rubber, manufactured by Chemours, product name "Viton GBL600S”) as an elastomer was dissolved in 0.3 g of methyl ethyl ketone to prepare an elastomer solution. 6 g of the CNT dispersion and 0.375 g of the elastomer solution were mixed to obtain an elastomer mixture. Next, the resulting elastomer mixture was applied onto a film-forming substrate.
  • FKM vinylene fluoride rubber, manufactured by Chemours, product name "Viton GBL600S”
  • the coating film on the film formation substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a sheet-like elastomer molding (composite material) on the film formation substrate.
  • the elastomer molded article was peeled off from the film-forming substrate to obtain an elastomer molded article.
  • the volume resistivity of the obtained elastomer molding was measured.
  • the measured value of volume resistivity was converted into an index value by setting the volume resistivity of the elastomer molding obtained in Comparative Example 6 described later as 100 (reference value).
  • Example 7 when comparing Example 7 with Comparative Example 6, which uses the same CNTs as in Example 7 but uses a different dispersion medium,
  • the elastomer molded article of Example 7 obtained using the CNT dispersion is Volume resistivity is lower than that of elastomer moldings. By this comparison, the effect of improving the electrical conductivity of the elastomer molded article in Example 7 can be confirmed.
  • the carbon nanotube dispersion liquid which can form the molded object excellent in electroconductivity can be provided.

Abstract

The purpose of the present invention is to provide a carbon nanotube dispersion capable of forming a molded body having excellent conductivity. A carbon nanotube dispersion according to the present invention contains carbon nanotubes and a dispersion medium. In addition, the absolute value of the difference between a polar term δp1 of the Hansen solubility parameters HSPc of the carbon nanotube and a polar term δp2 of the Hansen solubility parameters HSPd of the dispersion medium is 2.5 MPa1/2 or less.

Description

カーボンナノチューブ分散液、炭素膜の製造方法、エラストマー混合液、複合材料の製造方法、及びエラストマー成形体の製造方法Carbon nanotube dispersion, method for producing carbon membrane, mixture of elastomers, method for producing composite material, and method for producing elastomer molding
　本発明は、カーボンナノチューブ分散液、炭素膜の製造方法、エラストマー混合液、複合材料の製造方法、及びエラストマー成形体の製造方法に関する。 The present invention relates to a carbon nanotube dispersion, a carbon membrane manufacturing method, an elastomer mixture, a composite material manufacturing method, and an elastomer molding manufacturing method.
　従来、導電性、熱伝導性、及び強度などの特性に優れる材料として、カーボンナノチューブ（以下、「ＣＮＴ」と略記する場合がある。）が注目されている。 Carbon nanotubes (hereinafter sometimes abbreviated as "CNT") have been attracting attention as a material with excellent properties such as electrical conductivity, thermal conductivity, and strength.
　ここで、ＣＮＴは、一本一本の特性は優れているものの、外径が小さいためファンデルワールス力によってバンドル化し易い（束になり易い）。そのため、ＣＮＴを一旦分散媒に分散させてカーボンナノチューブ分散液を調製することが従来行われている。そして得られたＣＮＴ分散液は、複数本のＣＮＴが集合してなる炭素膜や、ＣＮＴとエラストマーを含んでなるエラストマー成形体（以下、炭素膜とエラストマー成形体をまとめて「成形体」と称する場合がある。）の製造に用いられる。 Here, although individual CNTs have excellent properties, they are easily bundled (bundles) due to the van der Waals force due to their small outer diameter. Therefore, conventionally, CNTs are once dispersed in a dispersion medium to prepare a carbon nanotube dispersion. The resulting CNT dispersion is a carbon film formed by aggregating a plurality of CNTs, or an elastomer molded body containing CNTs and an elastomer (hereinafter, the carbon film and the elastomer molded body are collectively referred to as a "molded body"). may be used).
　近年、ＣＮＴ分散液を改良することにより成形体の性能を向上させる試みがなされている。例えば特許文献１では、ＣＮＴ分散液の調製に際し、分散媒として、ハンセン溶解度パラメータの極性項、分散項、及び水素結合項がそれぞれ所定の範囲内である溶剤を用いることで、ＣＮＴ分散液中でＣＮＴを安定に分散させ、ＣＮＴが有する特性を維持したＣＮＴ複合膜を得る手法が提案されている。 In recent years, attempts have been made to improve the performance of compacts by improving CNT dispersions. For example, in Patent Document 1, when preparing a CNT dispersion, by using a solvent in which the polar term, the dispersion term, and the hydrogen bonding term of the Hansen solubility parameter are within predetermined ranges as a dispersion medium, Techniques for stably dispersing CNTs and obtaining a CNT composite film that maintains the properties of CNTs have been proposed.
特開２０２０－１６４３５４号公報JP 2020-164354 A
　しかしながら上記従来のＣＮＴ分散液には、ＣＮＴ分散液を用いて得られる成形体の導電性を高めるという点において、改善の余地があった。 However, the above-described conventional CNT dispersion has room for improvement in terms of increasing the electrical conductivity of the molded article obtained using the CNT dispersion.
　そこで、本発明は、導電性に優れる成形体を形成しうるカーボンナノチューブ分散液の提供を目的とする。
　また、本発明は、導電性に優れる炭素膜の製造方法の提供を目的とする。
　そして、本発明は、導電性に優れるエラストマー成形体の作製に使用し得る、エラストマー混合液、複合材料の製造方法、及びエラストマー成形体の製造方法の提供を目的とする。 Accordingly, an object of the present invention is to provide a carbon nanotube dispersion capable of forming a molded article having excellent conductivity.
Another object of the present invention is to provide a method for producing a carbon film having excellent conductivity.
It is another object of the present invention to provide an elastomer mixed liquid, a method for producing a composite material, and a method for producing an elastomer molded article, which can be used to produce an elastomer molded article having excellent conductivity.
　本発明者は、上記目的を達成するために鋭意検討を行った。本発明者は、ＣＮＴと分散媒とを含むＣＮＴ分散液の調製に際し、ＣＮＴ及び分散媒それぞれのハンセン溶解度パラメータの極性項に着目した。そして、ＣＮＴの極性項δｐ１と、分散媒の極性項δｐ２との差の絶対値（以下、|δｐ１－δｐ２|と称する場合がある。）が所定の値以下であるＣＮＴ分散液を用いて成形体を作製すれば、|δｐ１－δｐ２|が所定の値を超えた場合に比して、得られる成形体の導電性を高めうることを新たに見出し、本発明を完成させた。 The inventor of the present invention has made intensive studies in order to achieve the above object. In preparing a CNT dispersion containing CNTs and a dispersion medium, the present inventor focused on the polar terms of the Hansen solubility parameters of the CNTs and the dispersion medium. A CNT dispersion liquid in which the absolute value of the difference between the polar term δ p1 of the CNT and the polar term δ p2 of the dispersion medium (hereinafter sometimes referred to as |δ p1 −δ p2 |) is a predetermined value or less. When a molded body is produced using let me
　即ち、この発明は、上記課題を有利に解決することを目的とするものであり、本発明によれば、下記〔１〕～〔５〕のカーボンナノチューブ分散液、下記〔６〕の炭素膜の製造方法、下記〔７〕のエラストマー混合液、下記〔８〕の複合材料の製造方法、及び下記〔９〕のエラストマー成形体の製造方法が提供される。
〔１〕カーボンナノチューブと分散媒とを含むカーボンナノチューブ分散液であって、前記カーボンナノチューブのハンセン溶解度パラメータＨＳＰｃの極性項δｐ１と、前記分散媒のハンセン溶解度パラメータＨＳＰｄの極性項δｐ２との差の絶対値が２．５ＭＰａ１／２以下である、カーボンナノチューブ分散液。ＣＮＴと分散媒とを含み、|δｐ１－δｐ２|が上述した値以下であるＣＮＴ分散液を用いれば、導電性に優れる成形体を作製することができる。 That is, an object of the present invention is to advantageously solve the above problems. According to the present invention, the carbon nanotube dispersion liquid of the following [1] to [5] and the carbon film of the following [6] Provided are a production method, an elastomer mixed solution of [7] below, a method of producing a composite material of [8] below, and a method of producing an elastomer molding of [9] below.
[1] A carbon nanotube dispersion containing carbon nanotubes and a dispersion medium, wherein the polar term δ p1 of the Hansen solubility parameter HSP c of the carbon nanotube and the polar term δ p2 of the Hansen solubility parameter HSP d of the dispersion medium The absolute value of the difference between the carbon nanotube dispersions is 2.5 MPa 1/2 or less. By using a CNT dispersion containing CNTs and a dispersion medium and having |δ p1 −δ p2 | equal to or less than the above-mentioned value, a molded article having excellent conductivity can be produced.
〔２〕前記カーボンナノチューブの濃度が０．０１質量％以上５質量％以下である、上記〔１〕に記載のカーボンナノチューブ分散液。ＣＮＴの濃度が上述した範囲内であるＣＮＴ分散液を用いれば、得られる成形体の導電性を更に向上させることができる。 [2] The carbon nanotube dispersion liquid according to [1] above, wherein the concentration of the carbon nanotubes is 0.01% by mass or more and 5% by mass or less. By using a CNT dispersion having a CNT concentration within the range described above, the electrical conductivity of the resulting molded article can be further improved.
〔３〕前記カーボンナノチューブと前記分散媒とのハンセン溶解度パラメータの距離Ｒａが４．０ＭＰａ１／２以下である、上記〔１〕又は〔２〕に記載のカーボンナノチューブ分散液。ＣＮＴと分散媒とのハンセン溶解度パラメータの距離Ｒａが上述した値以下であれば、得られる成形体の導電性を更に向上させることができる。 [3] The carbon nanotube dispersion according to [1] or [2] above, wherein the distance Ra of the Hansen solubility parameter between the carbon nanotube and the dispersion medium is 4.0 MPa 1/2 or less. If the distance Ra of the Hansen Solubility Parameter between the CNT and the dispersion medium is equal to or less than the above-described value, the electrical conductivity of the resulting molded article can be further improved.
〔４〕前記分散媒のハンセン溶解度パラメータＨＳＰｄの分散項δｄ２が１７．５ＭＰａ１／２超である、上記〔１〕～〔３〕の何れかに記載のカーボンナノチューブ分散液。分散媒のハンセン溶解度パラメータＨＳＰｄの分散項δｄ２が上述した値を超えていれば、得られる成形体の導電性を更に向上させることができる。 [4] The carbon nanotube dispersion according to any one of [1] to [3] above, wherein the dispersion term δ d2 of the Hansen solubility parameter HSP d of the dispersion medium is more than 17.5 MPa 1/2 . If the dispersion term δ d2 of the Hansen solubility parameter HSP d of the dispersion medium exceeds the value described above, the electrical conductivity of the resulting molded article can be further improved.
〔５〕前記分散媒のハンセン溶解度パラメータＨＳＰｄの水素結合項δｈ２が９．０ＭＰａ１／２未満である、上記〔１〕～〔４〕の何れかに記載のカーボンナノチューブ分散液。分散媒のハンセン溶解度パラメータＨＳＰｄの水素結合項δｈ２が上述した値未満であれば、得られる成形体の導電性を更に向上させることができる。 [5] The carbon nanotube dispersion according to any one of [1] to [4] above, wherein the hydrogen bonding term δ h2 of the Hansen solubility parameter HSP d of the dispersion medium is less than 9.0 MPa 1/2 . If the hydrogen bonding term δ h2 of the Hansen solubility parameter HSP d of the dispersion medium is less than the above value, the electrical conductivity of the resulting molded product can be further improved.
〔６〕上記〔１〕～〔５〕の何れかに記載のカーボンナノチューブ分散液から前記分散媒を除去して成膜する工程を含む、炭素膜の製造方法。上述した何れかのＣＮＴ分散液から形成される炭素膜は、導電性に優れる。 [6] A method for producing a carbon film, comprising the step of forming a film by removing the dispersion medium from the carbon nanotube dispersion according to any one of [1] to [5] above. A carbon film formed from any of the CNT dispersions described above has excellent conductivity.
〔７〕上記〔１〕～〔５〕の何れかに記載のカーボンナノチューブ分散液と、エラストマーとを含む、エラストマー混合液。上述した何れかのＣＮＴ分散液とエラストマーとを混合して得られるエラストマー混合液を用いれば、導電性に優れるエラストマー成形体を作製することができる。 [7] An elastomer mixed liquid containing the carbon nanotube dispersion liquid according to any one of [1] to [5] above and an elastomer. By using an elastomer mixture obtained by mixing any of the CNT dispersions described above and an elastomer, an elastomer molded article having excellent conductivity can be produced.
〔８〕上記〔７〕に記載のエラストマー混合液から前記分散媒を除去する工程を含む、複合材料の製造方法。上述したエラストマー混合液を用いて得られる複合材料を用いれば、導電性に優れる成形体を作製することができる。 [8] A method for producing a composite material, comprising the step of removing the dispersion medium from the elastomer mixed liquid described in [7] above. By using a composite material obtained using the above-described elastomer mixture, a molded article having excellent conductivity can be produced.
〔９〕上記〔７〕に記載のエラストマー混合液から前記分散媒を除去して複合材料を得る工程と、前記複合材料に架橋剤を添加する工程と、前記架橋剤が添加された前記複合材料を架橋してエラストマー成形体を得る工程を含む、エラストマー成形体の製造方法。上述したエラストマー混合液を用いて得られる複合材料に架橋剤を加え、次いで架橋すれば、架橋体として、導電性に優れるエラストマー成形体を得ることができる。 [9] A step of removing the dispersion medium from the elastomer mixture described in [7] to obtain a composite material, adding a cross-linking agent to the composite material, and adding the cross-linking agent to the composite material. A method for producing an elastomer molded article, comprising the step of cross-linking to obtain an elastomer molded article. By adding a cross-linking agent to the composite material obtained by using the above-described elastomer mixed solution and then cross-linking, an elastomer molded article having excellent conductivity can be obtained as a cross-linked product.
　本明細書において、「カーボンナノチューブのハンセン溶解度パラメータ（ＨＳＰｃ）」は、極性項δｐ１、分散項δｄ１及び水素結合項δｈ１で構成され、「分散媒のハンセン溶解度パラメータ（ＨＳＰｄ）」は、極性項δｐ２、分散項δｄ２、及び水素結合項δｈ２で構成される。
　本明細書において、「δｐ１」、「δｄ１」及び「δｈ１」、並びに、「δｐ２」、「δｄ２」及び「δｈ２」は、実施例に記載の方法を用いて特定することができる。
　本明細書において、「ハンセン溶解度パラメータの距離Ｒａ」は、下記式（Ｉ）：
　　距離Ｒａ＝｛（δｐ１－δｐ２）２＋４×（δｄ１－δｄ２）２＋（δｈ１－δｈ２）２｝１／２・・・（Ｉ）
　を用いて算出することができる。 As used herein, the "Hansen solubility parameter of carbon nanotubes (HSP c )" is composed of the polar term δ p1 , the dispersion term δ d1 and the hydrogen bonding term δ h1 , and the "Hansen solubility parameter of the dispersion medium (HSP d )" is composed of a polar term δ p2 , a dispersion term δ d2 and a hydrogen bonding term δ h2 .
In the present specification, “δ p1 ”, “δ d1 ” and “δ h1 ”, and “δ p2 ”, “δ d2 ” and “δ h2 ” are specified using the method described in the examples. can be done.
As used herein, the "Hansen Solubility Parameter distance R a " is defined by the following formula (I):
Distance R a = {(δ p1 −δ p2 ) 2 +4×(δ d1 −δ d2 ) 2 +(δ h1 −δ h2 ) 2 } 1/2 (I)
can be calculated using
　本発明によれば、導電性に優れる成形体を形成しうるカーボンナノチューブ分散液を提供することができる。
　また、本発明によれば、導電性に優れる炭素膜の製造方法を提供することができる。
　そして、本発明によれば、導電性に優れるエラストマー成形体の作製に使用し得る、エラストマー混合液、複合材料の製造方法、及びエラストマー成形体の製造方法を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the carbon nanotube dispersion liquid which can form the molded object excellent in electroconductivity can be provided.
Moreover, according to the present invention, it is possible to provide a method for producing a carbon film having excellent conductivity.
Further, according to the present invention, it is possible to provide an elastomer mixed liquid, a method for producing a composite material, and a method for producing an elastomer molded article, which can be used to produce an elastomer molded article having excellent conductivity.
　以下、本発明の実施形態について詳細に説明する。
　ここで、本発明のＣＮＴ分散液は、炭素膜やエラストマー成形体に例示される成形体の作製に用いることができる。また、本発明の炭素膜の製造方法は、本発明のＣＮＴ分散液を用いて炭素膜を作製する方法である。そして、本発明のエラストマー混合液は、本発明のＣＮＴ分散液及びエラストマーを含み、複合材料及びエラストマー成形体の作製に用いることができる。また、本発明の複合材料の製造方法は、本発明のエラストマー混合液を用いて複合材料を作製する方法である。加えて、本発明のエラストマー成形体の製造方法は、本発明のエラストマー混合液を用いてエラストマー成形体を作製する方法である。 BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
Here, the CNT dispersion of the present invention can be used to produce molded articles such as carbon films and elastomer molded articles. Further, the method for producing a carbon membrane of the present invention is a method of producing a carbon membrane using the CNT dispersion of the present invention. The elastomer mixed liquid of the present invention contains the CNT dispersion of the present invention and an elastomer, and can be used for producing composite materials and elastomer moldings. A method for producing a composite material of the present invention is a method of producing a composite material using the elastomer mixture of the present invention. In addition, the method for producing an elastomer molded article of the present invention is a method of producing an elastomer molded article using the elastomer mixed liquid of the present invention.
（カーボンナノチューブ分散液）
　本発明のＣＮＴ分散液は、ＣＮＴと分散媒とを含み、任意に、ＣＮＴと分散媒以外の成分（その他の成分）を含んでいてもよい。
　ここで、本発明のＣＮＴ分散液は、ＣＮＴのハンセン溶解度パラメータＨＳＰｃの極性項δｐ１と、分散媒のハンセン溶解度パラメータＨＳＰｄの極性項δｐ２との差の絶対値が２．５ＭＰａ１／２以下であることを大きな特徴の一つとする。|δｐ１－δｐ２|の値が２．５ＭＰａ１／２以下であれば、ＣＮＴと分散媒との親和性が高まるためＣＮＴのバンドル構造体の内部に分散媒が容易に侵入してＣＮＴを良好に分散させると推察される。このＣＮＴの分散性向上効果に因るものと考えられるが、|δｐ１－δｐ２|の値が２．５ＭＰａ１／２以下である本発明のＣＮＴ分散液を用いて得られる成形体では、ＣＮＴが良好な導電パスを形成し、当該成形体は優れた導電性を発揮することができる。 (Carbon nanotube dispersion)
The CNT dispersion of the present invention contains CNTs and a dispersion medium, and may optionally contain components (other components) other than the CNTs and the dispersion medium.
Here, in the CNT dispersion of the present invention, the absolute value of the difference between the polar term δ p1 of the Hansen solubility parameter HSP c of the CNT and the polar term δ p2 of the Hansen solubility parameter HSP d of the dispersion medium is 2.5 MPa 1/ One of the major features is that it is 2 or less. If the value of |δ p1 −δ p2 | is 2.5 MPa 1/2 or less, the affinity between the CNTs and the dispersion medium increases, so that the dispersion medium easily penetrates into the CNT bundle structure to disperse the CNTs. It is assumed to disperse well. It is thought that this is due to the effect of improving the dispersibility of CNTs . CNTs form good conductive paths, and the molded article can exhibit excellent conductivity.
　なお、本発明のＣＮＴ分散液を用いて得られる成形体中では、従来のＣＮＴ分散液を用いた場合に比してＣＮＴのバンドル構造体の数が抑制されており、当該成形体は、導電性のみならずＣＮＴが有する他の特性（熱伝導性及び強度など）も良好に発揮することができる。そのため、本発明のＣＮＴ分散液を用いて得られる成形体は、導電性が求められる用途のみならず、ＣＮＴの他の特性が求められる任意の用途に使用可能である。 In addition, in the molded article obtained using the CNT dispersion of the present invention, the number of CNT bundle structures is suppressed as compared with the case of using a conventional CNT dispersion, and the molded article is electrically conductive. Other properties of CNTs (thermal conductivity, strength, etc.) can also be exhibited satisfactorily. Therefore, the molded article obtained using the CNT dispersion of the present invention can be used not only for applications requiring electrical conductivity but also for any application requiring other properties of CNTs.
＜カーボンナノチューブ＞
　本発明のＣＮＴ分散液に含まれるＣＮＴは、ＨＳＰｃを構成する極性項δｐ１について、後述する分散媒のＨＳＰｄの極性項δｐ２との兼合いで|δｐ１－δｐ２|の値が２．５ＭＰａ１／２以下であれば特に限定されず、任意のＣＮＴを用いることができる。 <Carbon nanotube>
In the CNTs contained in the CNT dispersion of the present invention, the value of |δ p1 −δ p2 | Any CNT can be used without any particular limitation as long as it is 2.5 MPa 1/2 or less.
＜＜ハンセン溶解度パラメータＨＳＰｃ＞＞
　ＨＳＰｃは、上述した通り極性項δｐ１、分散項δｄ１及び水素結合項δｈ１の三つで構成される。 <<Hansen Solubility Parameter HSP c >>
HSP c is composed of three terms, the polar term δ p1 , the dispersion term δ d1 and the hydrogen bonding term δ h1 , as described above.
　極性項δｐ１は、特に限定されないが、成形体の導電性を更に向上させる観点から、２．０ＭＰａ１／２以上であることが好ましく、３．０ＭＰａ１／２以上であることがより好ましく、４．０ＭＰａ１／２以上であることが更に好ましく、５．５ＭＰａ１／２以上であることが特に好ましく、１５．０ＭＰａ１／２以下であることが好ましく、１３．０ＭＰａ１／２以下であることがより好ましく、１１．０ＭＰａ１／２以下であることが更に好ましい。
　分散項δｄ１は、特に限定されないが、成形体の導電性を更に向上させる観点から、１３．０ＭＰａ１／２以上であることが好ましく、１５．０ＭＰａ１／２以上であることがより好ましく、１７．５ＭＰａ１／２以上であることが更に好ましく、２３．０ＭＰａ１／２以下であることが好ましく、２１．０ＭＰａ１／２以下であることがより好ましく、１９．０ＭＰａ１／２以下であることが更に好ましい。
　水素結合項δｈ１は、特に限定されないが、成形体の導電性を更に向上させる観点から、１．０ＭＰａ１／２以上であることが好ましく、２．０ＭＰａ１／２以上であることがより好ましく、３．０ＭＰａ１／２以上であることが更に好ましく、１２．０ＭＰａ１／２以下であることが好ましく、１０．０ＭＰａ１／２以下であることがより好ましく、７．０ＭＰａ１／２以下であることが更に好ましい。 Although the polarity term δ p1 is not particularly limited, it is preferably 2.0 MPa 1/2 or more, more preferably 3.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body. It is more preferably 4.0 MPa 1/2 or more, particularly preferably 5.5 MPa 1/2 or more, preferably 15.0 MPa 1/2 or less, and 13.0 MPa 1/2 or less. is more preferably 11.0 MPa 1/2 or less.
Although the dispersion term δ d1 is not particularly limited, it is preferably 13.0 MPa 1/2 or more, more preferably 15.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body. It is more preferably 17.5 MPa 1/2 or more, preferably 23.0 MPa 1/2 or less, more preferably 21.0 MPa 1/2 or less, and 19.0 MPa 1/2 or less. is more preferred.
The hydrogen bond term δ h1 is not particularly limited, but is preferably 1.0 MPa 1/2 or more, more preferably 2.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body. , More preferably 3.0 MPa 1/2 or more, preferably 12.0 MPa 1/2 or less, more preferably 10.0 MPa 1/2 or less, and 7.0 MPa 1/2 or less It is even more preferable to have
　なお、ＣＮＴのハンセン溶解度パラメータ（ＨＳＰｃ）は、ＣＮＴの直径、ＣＮＴ表面の欠陥量や官能基量により影響を受けると考えられ、例えば、ＣＮＴの製造条件、ＣＮＴの表面処理条件などを変更することで調整することができる。 The Hansen solubility parameter (HSP c ) of CNTs is thought to be affected by the diameter of CNTs, the amount of defects on the surface of CNTs, and the amount of functional groups. can be adjusted by
＜＜ＨＳＰｃ以外の性状＞＞
　ＣＮＴとしては、特に限定されることなく、単層カーボンナノチューブ及び／又は多層カーボンナノチューブを用いることができるが、ＣＮＴは、単層から５層までのカーボンナノチューブであることが好ましく、単層カーボンナノチューブであることがより好ましい。単層ＣＮＴを用いれば、配合量が少量であっても成形体の導電性が十分に向上するからである。
　なお、本発明のＣＮＴ分散液には、通常、複数本のＣＮＴが含まれる。また、本発明のＣＮＴ分散液は、ＣＮＴとして、単層から５層までのＣＮＴを含むことが好ましく、単層ＣＮＴを含むことがより好ましい。その上、本発明のＣＮＴ分散液は、ＣＮＴとして、単層から５層までのＣＮＴを主として含むことがより好ましく、単層ＣＮＴを主として含むことが更に好ましい。
　なお、あるＣＮＴを「主として含む」とは、ＣＮＴ分散液に含まれる複数本のＣＮＴの全本数のうち、半数超が当該あるＣＮＴであることを意味する。 <<Properties other than HSP c >>
CNTs are not particularly limited, and single-walled carbon nanotubes and/or multi-walled carbon nanotubes can be used. CNTs are preferably single-walled to five-walled carbon nanotubes. is more preferable. This is because if single-walled CNTs are used, the electrical conductivity of the compact is sufficiently improved even if the blending amount is small.
In addition, the CNT dispersion liquid of the present invention usually contains a plurality of CNTs. In addition, the CNT dispersion of the present invention preferably contains single-walled to five-walled CNTs, more preferably single-walled CNTs. In addition, the CNT dispersion of the present invention more preferably mainly contains single-walled to five-walled CNTs, and more preferably mainly single-walled CNTs.
Note that “mainly containing” a certain CNT means that more than half of the total number of the plurality of CNTs contained in the CNT dispersion is the certain CNT.
　また、ＣＮＴの平均直径は、１ｎｍ以上であることが好ましく、６０ｎｍ以下であることが好ましく、３０ｎｍ以下であることがより好ましく、１０ｎｍ以下であることが更に好ましい。ＣＮＴの平均直径を上記範囲内とすれば、成形体の導電性を更に向上させることができる。
　本明細書において、ＣＮＴの「平均直径」は、透過型電子顕微鏡（ＴＥＭ）画像上で、無作為に選択した２０本のＣＮＴについて直径（外径）を測定し、それら測定値の算術平均値として求めることができる。 The average diameter of CNTs is preferably 1 nm or more, preferably 60 nm or less, more preferably 30 nm or less, and even more preferably 10 nm or less. By setting the average diameter of the CNTs within the above range, the electrical conductivity of the compact can be further improved.
As used herein, the "average diameter" of CNTs is the arithmetic mean value of the diameters (outer diameters) of 20 randomly selected CNTs measured on a transmission electron microscope (TEM) image. can be obtained as
　また、ＣＮＴとしては、平均直径（Ａｖ）に対する、直径の標準偏差（σ：標本標準偏差）に３を乗じた値（３σ）の比（３σ／Ａｖ）が０．２０超０．８０未満のＣＮＴを用いることが好ましく、３σ／Ａｖが０．２０超０．６０未満のＣＮＴを用いることがより好ましく、３σ／Ａｖが０．２５超のＣＮＴを用いることが更に好ましく、３σ／Ａｖが０．５０超のＣＮＴを用いることが特に好ましい。３σ／Ａｖが０．２０超０．８０未満のＣＮＴを使用すれば、成形体の導電性を更に向上させることができる。
　なお、ＣＮＴの平均直径（Ａｖ）及び標準偏差（σ）は、ＣＮＴの製造方法や製造条件を変更することにより調整してもよいし、異なる製法で得られたＣＮＴを複数種類組み合わせることにより調整してもよい。 In addition, as the CNT, the ratio (3σ) of the value (3σ) obtained by multiplying the standard deviation of the diameter (σ: sample standard deviation) by 3 to the average diameter (Av) is more than 0.20 and less than 0.80. It is preferable to use CNTs, more preferably 3σ/Av is more than 0.20 and less than 0.60, more preferably 3σ/Av is more than 0.25, and 3σ/Av is 0 It is particularly preferred to use CNTs greater than 0.50. Using CNTs with a 3σ/Av of more than 0.20 and less than 0.80 can further improve the electrical conductivity of the compact.
The average diameter (Av) and standard deviation (σ) of CNTs may be adjusted by changing the CNT manufacturing method or manufacturing conditions, or by combining multiple types of CNTs obtained by different manufacturing methods. You may
　そして、ＣＮＴとしては、前述のようにして測定した直径を横軸に、その頻度を縦軸に取ってプロットし、ガウシアンで近似した際に、正規分布を取るものが通常使用される。 As the CNT, the diameter measured as described above is plotted on the horizontal axis and the frequency is plotted on the vertical axis, and when Gaussian approximation is performed, a normal distribution is usually used.
　また、ＣＮＴは、平均長さが、１０μｍ以上であることが好ましく、５０μｍ以上であることがより好ましく、８０μｍ以上であることが更に好ましく、６００μｍ以下であることが好ましく、５５０μｍ以下であることがより好ましく、５００μｍ以下であることが更に好ましい。ＣＮＴの平均長さを上記範囲内とすれば、成形体の導電性を更に向上させることができる。
　本明細書において、ＣＮＴの「平均長さ」は、走査型電子顕微鏡（ＳＥＭ）画像上で、無作為に選択した２０本のＣＮＴについて長さを測定し、それら測定値の算術平均値として求めることができる。 The average length of the CNTs is preferably 10 µm or more, more preferably 50 µm or more, even more preferably 80 µm or more, preferably 600 µm or less, and preferably 550 µm or less. More preferably, it is 500 μm or less. By setting the average length of the CNTs within the above range, the electrical conductivity of the molded product can be further improved.
As used herein, the "average length" of CNTs is obtained by measuring the length of 20 randomly selected CNTs on a scanning electron microscope (SEM) image and calculating the arithmetic mean of the measured values. be able to.
　さらに、ＣＮＴは、通常、アスペクト比が１０超である。なお、ＣＮＴのアスペクト比は、走査型電子顕微鏡又は透過型電子顕微鏡を用いて、無作為に選択したＣＮＴ２０本の直径及び長さを測定し、直径と長さとの比（長さ／直径）の平均値を算出することにより求めることができる。 Furthermore, CNTs usually have an aspect ratio of more than 10. The aspect ratio of CNTs is determined by measuring the diameter and length of 20 randomly selected CNTs using a scanning electron microscope or transmission electron microscope, and measuring the ratio of the diameter to the length (length/diameter). It can be obtained by calculating the average value.
　また、ＣＮＴは、ＢＥＴ比表面積が、３００ｍ２／ｇ以上であることが好ましく、４００ｍ２／ｇ以上であることがより好ましく、２０００ｍ２／ｇ以下であることが好ましく、１８００ｍ２／ｇ以下であることがより好ましく、１６００ｍ２／ｇ以下であることが更に好ましい。ＣＮＴのＢＥＴ比表面積が３００ｍ２／ｇ以上であれば、少ない配合量で成形体の導電性を十分に高めることができる。また、ＣＮＴのＢＥＴ比表面積が２０００ｍ２／ｇ以下であれば、ＣＮＴのバンドル構造体を良好に解繊して成形体の導電性を更に向上させることができる。
　本明細書において、「ＢＥＴ比表面積」とは、ＢＥＴ法を用いて測定した窒素吸着比表面積を指す。 In addition, the CNT preferably has a BET specific surface area of 300 m 2 /g or more, more preferably 400 m 2 /g or more, preferably 2000 m 2 /g or less, and 1800 m 2 /g or less. It is more preferably 1600 m 2 /g or less. If the BET specific surface area of CNTs is 300 m 2 /g or more, the electrical conductivity of the compact can be sufficiently increased with a small amount. Further, when the BET specific surface area of the CNTs is 2000 m 2 /g or less, the CNT bundle structure can be defibrated satisfactorily and the electrical conductivity of the compact can be further improved.
As used herein, the term "BET specific surface area" refers to the nitrogen adsorption specific surface area measured using the BET method.
　また、ＣＮＴは、吸着等温線から得られるｔ－プロットが上に凸な形状を示すことが好ましい。なお、「ｔ－プロット」は、窒素ガス吸着法により測定されたＣＮＴの吸着等温線において、相対圧を窒素ガス吸着層の平均厚みｔ（ｎｍ）に変換することにより得ることができる。すなわち、窒素ガス吸着層の平均厚みｔを相対圧Ｐ／Ｐ０に対してプロットした、既知の標準等温線から、相対圧に対応する窒素ガス吸着層の平均厚みｔを求めて上記変換を行うことにより、ＣＮＴのｔ－プロットが得られる（de Boerらによるｔ－プロット法）。
　なお、吸着等温線から得られるｔ－プロットが上に凸な形状を示すＣＮＴは、開口処理が施されていないＣＮＴであることが好ましい。 In addition, CNTs preferably show an upward convex shape in the t-plot obtained from the adsorption isotherm. The "t-plot" can be obtained by converting the relative pressure to the average thickness t (nm) of the nitrogen gas adsorption layer in the CNT adsorption isotherm measured by the nitrogen gas adsorption method. That is, the average thickness t of the nitrogen gas adsorption layer corresponding to the relative pressure is obtained from a known standard isotherm obtained by plotting the average thickness t of the nitrogen gas adsorption layer against the relative pressure P/P0, and the above conversion is performed. gives a t-plot of CNTs (t-plot method by de Boer et al.).
It should be noted that CNTs exhibiting a convex shape in the t-plot obtained from the adsorption isotherm are preferably CNTs that have not undergone opening treatment.
　ここで、表面に細孔を有する物質では、窒素ガス吸着層の成長は、次の（１）～（３）の過程に分類される。そして、下記の（１）～（３）の過程によって、ｔ－プロットの傾きに変化が生じる。
（１）全表面への窒素分子の単分子吸着層形成過程
（２）多分子吸着層形成とそれに伴う細孔内での毛管凝縮充填過程
（３）細孔が窒素によって満たされた見かけ上の非多孔性表面への多分子吸着層形成過程 Here, the growth of a nitrogen gas adsorption layer on a substance having pores on its surface is classified into the following processes (1) to (3). Then, the slope of the t-plot changes due to the following processes (1) to (3).
(1) Formation of a monomolecular adsorption layer of nitrogen molecules on the entire surface (2) Formation of a multimolecular adsorption layer and subsequent capillary condensation filling process within the pores (3) Posterior pores filled with nitrogen Formation process of polymolecular adsorption layer on non-porous surface
　そして、上に凸な形状を示すｔ－プロットは、窒素ガス吸着層の平均厚みｔが小さい領域では、原点を通る直線上にプロットが位置するのに対し、ｔが大きくなると、プロットが当該直線から下にずれた位置となる。かかるｔ－プロットの形状を有するＣＮＴは、ＣＮＴの全比表面積に対する内部比表面積の割合が大きく、ＣＮＴに多数の開口が形成されていることを示している。 Then, the t-plot showing an upwardly convex shape is located on a straight line passing through the origin in a region where the average thickness t of the nitrogen gas adsorption layer is small, whereas when t becomes large, the plot is on the straight line. position shifted downward from A CNT having such a t-plot shape has a large ratio of the internal specific surface area to the total specific surface area of the CNT, indicating that many openings are formed in the CNT.
　なお、ＣＮＴのｔ－プロットの屈曲点は、０．２≦ｔ（ｎｍ）≦１．５を満たす範囲にあることが好ましく、０．４５≦ｔ（ｎｍ）≦１．５の範囲にあることがより好ましく、０．５５≦ｔ（ｎｍ）≦１．０の範囲にあることが更に好ましい。ＣＮＴのｔ－プロットの屈曲点がかかる範囲内にあれば、少ない配合量で成形体の特性（例えば、導電性、熱伝導性、強度など）を高めることができる。
　なお、「屈曲点の位置」は、前述した（１）の過程の近似直線Ａと、前述した（３）の過程の近似直線Ｂとの交点である。 The inflection point of the t-plot of CNT is preferably in the range that satisfies 0.2 ≤ t (nm) ≤ 1.5, and is in the range of 0.45 ≤ t (nm) ≤ 1.5. is more preferable, and it is even more preferable to be in the range of 0.55≦t(nm)≦1.0. If the inflection point of the t-plot of CNT is within this range, it is possible to improve the properties (eg electrical conductivity, thermal conductivity, strength, etc.) of the molded product with a small amount.
The "position of the bending point" is the intersection of the approximate straight line A in the process (1) described above and the approximate straight line B in the process (3) described above.
　更に、ＣＮＴは、ｔ－プロットから得られる全比表面積Ｓ１に対する内部比表面積Ｓ２の比（Ｓ２／Ｓ１）が０．０５以上０．３０以下であるのが好ましい。ＣＮＴのＳ２／Ｓ１の値がかかる範囲内であれば、少ない配合量で成形体の導電性を十分に高めることができる。
　ここで、ＣＮＴの全比表面積Ｓ１及び内部比表面積Ｓ２は、そのｔ－プロットから求めることができる。具体的には、まず、（１）の過程の近似直線の傾きから全比表面積Ｓ１を、（３）の過程の近似直線の傾きから外部比表面積Ｓ３を、それぞれ求めることができる。そして、全比表面積Ｓ１から外部比表面積Ｓ３を差し引くことにより、内部比表面積Ｓ２を算出することができる。 Furthermore, the CNT preferably has a ratio (S2/S1) of internal specific surface area S2 to total specific surface area S1 obtained from t-plot of 0.05 or more and 0.30 or less. If the S2/S1 value of CNT is within such a range, the electrical conductivity of the molded article can be sufficiently enhanced with a small compounding amount.
Here, the total specific surface area S1 and the internal specific surface area S2 of CNT can be obtained from the t-plot. Specifically, first, the total specific surface area S1 can be obtained from the slope of the approximate straight line in process (1), and the external specific surface area S3 can be obtained from the slope of the approximate straight line in process (3). By subtracting the external specific surface area S3 from the total specific surface area S1, the internal specific surface area S2 can be calculated.
　因みに、ＣＮＴの吸着等温線の測定、ｔ－プロットの作成、及び、ｔ－プロットの解析に基づく全比表面積Ｓ１と内部比表面積Ｓ２との算出は、例えば、市販の測定装置である「ＢＥＬＳＯＲＰ（登録商標）－ｍｉｎｉ」（日本ベル（株）製）を用いて行うことができる。 By the way, the measurement of the adsorption isotherm of CNT, the creation of the t-plot, and the calculation of the total specific surface area S1 and the internal specific surface area S2 based on the analysis of the t-plot can be performed, for example, by a commercially available measurement device "BELSORP ( (registered trademark)-mini” (manufactured by Nippon Bell Co., Ltd.).
　更に、ＣＮＴは、ラマン分光法を用いて評価した際に、Ｒａｄｉａｌ Ｂｒｅａｔｈｉｎｇ Ｍｏｄｅ（ＲＢＭ）のピークを有することが好ましい。なお、三層以上の多層ＣＮＴのラマンスペクトルには、ＲＢＭが存在しない。 Furthermore, CNTs preferably have a Radial Breathing Mode (RBM) peak when evaluated using Raman spectroscopy. In addition, RBM does not exist in the Raman spectrum of multilayer CNTs having three or more layers.
　また、ＣＮＴは、ラマンスペクトルにおけるＤバンドピーク強度に対するＧバンドピーク強度の比（Ｇ／Ｄ比）が０．５以上５．０以下であることが好ましい。Ｇ／Ｄ比が０．５以上５．０以下であれば、成形体の導電性を更に向上させることができる。
　なお本明細書において、Ｇ／Ｄ比は、顕微レーザラマン分光光度計（サーモフィッシャーサイエンティフィック（株）製Ｎｉｃｏｌｅｔ　Ａｌｍｅｇａ　ＸＲ）を使用してラマンスペクトルを計測し、得られたラマンスペクトルについて、１５９０ｃｍ-1近傍で観察されるＧバンドピークの強度と、１３４０ｃｍ-1近傍で観察されるＤバンドピークの強度とを求めて算出することができる。 In addition, the CNT preferably has a ratio of G-band peak intensity to D-band peak intensity (G/D ratio) in the Raman spectrum of 0.5 or more and 5.0 or less. If the G/D ratio is 0.5 or more and 5.0 or less, the electrical conductivity of the molded article can be further improved.
In this specification, the G/D ratio is measured using a microlaser Raman spectrophotometer (Nicolet Almega XR manufactured by Thermo Fisher Scientific Co., Ltd.), and the obtained Raman spectrum is 1590 cm − It can be calculated by obtaining the intensity of the G band peak observed near 1 and the intensity of the D band peak observed near 1340 cm −1 .
＜＜ＣＮＴの製造方法＞＞
　なお、ＣＮＴは、特に限定されることなく、アーク放電法、レーザーアブレーション法、化学的気相成長法（ＣＶＤ法）などの既知のＣＮＴの合成方法を用いて製造することができる。具体的には、ＣＮＴは、例えば、ＣＮＴ製造用の触媒層を表面に有する基材上に原料化合物及びキャリアガスを供給し、化学的気相成長法（ＣＶＤ法）によりＣＮＴを合成する際に、系内に微量の酸化剤（触媒賦活物質）を存在させることで、触媒層の触媒活性を飛躍的に向上させるという方法（スーパーグロース法；国際公開第２００６／０１１６５５号参照）に準じて、効率的に製造することができる。なお、以下では、スーパーグロース法により得られるＣＮＴを「ＳＧＣＮＴ」と称することがある。
　そして、スーパーグロース法により製造されたＣＮＴは、ＳＧＣＮＴのみから構成されていてもよいし、ＳＧＣＮＴに加え、例えば、非円筒形状の炭素ナノ構造体等の他の炭素ナノ構造体を含んでいてもよい。 <<Manufacturing method of CNT>>
CNTs can be produced by known CNT synthesis methods such as an arc discharge method, a laser ablation method, and a chemical vapor deposition method (CVD method), without any particular limitation. Specifically, CNTs are synthesized, for example, by supplying a raw material compound and a carrier gas onto a substrate having a catalyst layer for CNT production on its surface, and synthesizing CNTs by chemical vapor deposition (CVD). , A method of dramatically improving the catalytic activity of the catalyst layer by allowing a trace amount of oxidizing agent (catalyst activating substance) to be present in the system (super-growth method; see WO 2006/011655), It can be manufactured efficiently. In addition, below, the CNT obtained by the super-growth method may be referred to as "SGCNT".
The CNTs produced by the super-growth method may consist only of SGCNTs, or may contain other carbon nanostructures such as non-cylindrical carbon nanostructures in addition to SGCNTs. good.
＜＜ＣＮＴの濃度＞＞
　本発明のＣＮＴ分散液中におけるＣＮＴの濃度（含有割合）は、ＣＮＴ分散液の質量を１００質量％として、０．０１質量％以上であることが好ましく、０．０３質量％以上であることがより好ましく、５質量％以下であることが好ましく、３質量％以下であることがより好ましく、１質量％以下であることが更に好ましく、０．５質量％以下であることが特に好ましい。ＣＮＴ分散液中におけるＣＮＴの濃度が上述した範囲内であれば、成形体の導電性を更に向上させることができる。 <<concentration of CNT>>
The concentration (content ratio) of CNTs in the CNT dispersion of the present invention is preferably 0.01% by mass or more, and preferably 0.03% by mass or more, with the mass of the CNT dispersion being 100% by mass. It is more preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less. If the CNT concentration in the CNT dispersion is within the range described above, the electrical conductivity of the compact can be further improved.
＜分散媒＞
　本発明のＣＮＴ分散液に含まれる分散媒は、ＨＳＰｄを構成する極性項δｐ２について、上述したＣＮＴのＨＳＰｃの極性項δｐ１との兼合いで|δｐ１－δｐ２|の値が２．５ＭＰａ１／２以下であれば特に限定されず、任意の分散媒を用いることができる。 <Dispersion medium>
In the dispersion medium contained in the CNT dispersion of the present invention, the value of |δ p1 −δ p2 | Any dispersion medium can be used without any particular limitation as long as it is 2.5 MPa 1/2 or less.
＜＜ハンセン溶解度パラメータＨＳＰｄ＞＞
　ＨＳＰｄは、上述した通り極性項δｐ２、分散項δｄ２及び水素結合項δｈ２の三つで構成される。 <<Hansen Solubility Parameter HSP d >>
HSP d is composed of three terms, the polar term δ p2 , the dispersion term δ d2 and the hydrogen bonding term δ h2 , as described above.
　極性項δｐ２は、特に限定されないが、成形体の導電性を更に向上させる観点から、３．０ＭＰａ１／２以上であることが好ましく、４．０ＭＰａ１／２以上であることがより好ましく、５．０ＭＰａ１／２以上であることが更に好ましく、６．２ＭＰａ１／２以上であることが特に好ましく、１４．０ＭＰａ１／２以下であることが好ましく、１２．０ＭＰａ１／２以下であることがより好ましく、１０．０ＭＰａ１／２以下であることが更に好ましい。
　分散項δｄ２は、特に限定されないが、成形体の導電性を更に向上させる観点から、１３．０ＭＰａ１／２以上であることが好ましく、１５．０ＭＰａ１／２以上であることがより好ましく、１７．５ＭＰａ１／２超であることが更に好ましく、２４．０ＭＰａ１／２以下であることが好ましく、２２．０ＭＰａ１／２以下であることがより好ましく、２０．０ＭＰａ１／２以下であることが更に好ましい。
　水素結合項δｈ２は、特に限定されないが、成形体の導電性を更に向上させる観点から、１．０ＭＰａ１／２以上であることが好ましく、２．０ＭＰａ１／２以上であることがより好ましく、２．５ＭＰａ１／２以上であることが更に好ましく、９．０ＭＰａ１／２未満であることが好ましく、７．０ＭＰａ１／２以下であることがより好ましく、５．０ＭＰａ１／２以下であることが更に好ましい。 The polar term δ p2 is not particularly limited, but is preferably 3.0 MPa 1/2 or more, more preferably 4.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body. It is more preferably 5.0 MPa 1/2 or more, particularly preferably 6.2 MPa 1/2 or more, preferably 14.0 MPa 1/2 or less, and 12.0 MPa 1/2 or less. is more preferable, and 10.0 MPa 1/2 or less is even more preferable.
Although the dispersion term δ d2 is not particularly limited, it is preferably 13.0 MPa 1/2 or more, more preferably 15.0 MPa 1/2 or more, from the viewpoint of further improving the conductivity of the molded body. It is more preferably more than 17.5 MPa 1/2 , preferably 24.0 MPa 1/2 or less, more preferably 22.0 MPa 1/2 or less, and 20.0 MPa 1/2 or less. is more preferred.
The hydrogen bonding term δ h2 is not particularly limited, but from the viewpoint of further improving the conductivity of the molded body, it is preferably 1.0 MPa 1/2 or more, more preferably 2.0 MPa 1/2 or more. , More preferably 2.5 MPa 1/2 or more, preferably less than 9.0 MPa 1/2 , more preferably 7.0 MPa 1/2 or less, and 5.0 MPa 1/2 or less It is even more preferable to have
　なお、分散媒のハンセン溶解度パラメータ（ＨＳＰｄ）は、分散媒の種類を変更することで調整することができる。また、分散媒として複数種の成分（水又は有機溶媒）を組み合わせて用いる場合は、各成分の混合比率を変更することで調整することができる。 The Hansen solubility parameter (HSP d ) of the dispersion medium can be adjusted by changing the type of dispersion medium. In addition, when using a combination of a plurality of components (water or organic solvent) as a dispersion medium, it can be adjusted by changing the mixing ratio of each component.
＜＜分散媒の例＞＞
　そして分散媒としては、有機溶媒が好ましく用いられ、具体的には、アセトフェノン、ｐ－クロロトルエン、メチルエチルケトン、シクロヘキサノン（以下、これらをまとめて「上記４種の有機溶媒」と称する場合がある。）が好ましく、アセトフェノン、ｐ－クロロトルエンがより好ましい。
　なお分散媒は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。例えば、本発明のＣＮＴ分散液は、分散媒として、上記４種の有機溶媒からなる群から選択される１種のみを含んでいてもよいし、上記４種の有機溶媒からなる群から選択される２種以上を含んでいてもよい。加えて、本発明のＣＮＴ分散液は、分散媒として、上記４種の有機溶媒からなる群から選択される少なくとも１種と、上記４種の有機溶媒以外の有機溶媒及び水からなる群から選択される少なくとも１種との双方を含んでいてもよい。 <<Example of dispersion medium>>
As the dispersion medium, an organic solvent is preferably used, and specifically, acetophenone, p-chlorotoluene, methyl ethyl ketone, and cyclohexanone (these are sometimes collectively referred to as "the above four organic solvents"). is preferred, and acetophenone and p-chlorotoluene are more preferred.
In addition, a dispersion medium may be used individually by 1 type, and may be used in combination of 2 or more types. For example, the CNT dispersion of the present invention may contain, as a dispersion medium, only one type selected from the group consisting of the four types of organic solvents described above, or may contain only one selected from the group consisting of the four types of organic solvents described above. It may contain two or more kinds. In addition, in the CNT dispersion of the present invention, as a dispersion medium, at least one selected from the group consisting of the above four organic solvents, an organic solvent other than the above four organic solvents, and water. and at least one of the above may be included.
＜＜分散媒の含有割合＞＞
　本発明のＣＮＴ分散液中における分散媒の含有割合は、ＣＮＴ分散液の質量を１００質量％として、９５質量％以上であることが好ましく、９７質量％以上であることがより好ましく、９９質量％以上であることが更に好ましく、９９．５質量％以上であることが特に好ましく、９９．９９質量％以下であることが好ましく、９９．９７質量％以下であることがより好ましい。ＣＮＴ分散液中における分散媒の含有割合が上述した範囲内であれば、成形体の導電性を更に向上させることができる。 <<Content ratio of dispersion medium>>
The content of the dispersion medium in the CNT dispersion of the present invention is preferably 95% by mass or more, more preferably 97% by mass or more, more preferably 99% by mass, with the mass of the CNT dispersion being 100% by mass. It is more preferably 99.5% by mass or more, particularly preferably 99.5% by mass or more, preferably 99.99% by mass or less, and more preferably 99.97% by mass or less. If the content of the dispersion medium in the CNT dispersion is within the range described above, the electrical conductivity of the compact can be further improved.
＜その他の成分＞
　上述したＣＮＴ及び分散媒以外にＣＮＴ分散液が含み得る成分としては、分散剤や、その他複合材料及び成形体の調製に用いうる、エラストマー以外の既知の添加剤が挙げられる。なお、その他の成分は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。
　しかしながら、ＣＮＴ分散液の分散性を十分確保しつつ成形体の導電性を更に向上させる観点から、ＣＮＴ分散液中におけるその他の成分の含有割合は、ＣＮＴ分散液の質量を１００質量％として、１０質量％以下であることが好ましく、５質量％以下であることがより好ましく、１質量％以下であることが更に好ましく、０．１質量％以下であることが特に好ましく、０．０１質量％以下であることが最も好ましい。 <Other ingredients>
In addition to the CNTs and dispersion medium described above, the components that the CNT dispersion may contain include dispersants and other known additives other than elastomers that can be used in the preparation of composite materials and moldings. In addition, another component may be used individually by 1 type, and may be used in combination of 2 or more type.
However, from the viewpoint of further improving the electrical conductivity of the compact while sufficiently ensuring the dispersibility of the CNT dispersion, the content of other components in the CNT dispersion is set to 10%, where the mass of the CNT dispersion is 100% by mass. It is preferably no more than 5% by mass, more preferably no more than 5% by mass, even more preferably no more than 1% by mass, particularly preferably no more than 0.1% by mass, and no more than 0.01% by mass. is most preferred.
＜|δｐ１－δｐ２|＞
　そして、本発明のＣＮＴ分散液は、上述した通り、ＣＮＴのハンセン溶解度パラメータＨＳＰｃの極性項δｐ１と、分散媒のハンセン溶解度パラメータＨＳＰｄの極性項δｐ２との差の絶対値が、２．５ＭＰａ１／２以下であることが必要であり、２．０ＭＰａ１／２以下であることが好ましく、１．７ＭＰａ１／２以下であることがより好ましく、１．５ＭＰａ１／２以下であることが更に好ましく、１．１ＭＰａ１／２以下であることが一層好ましく、０．８ＭＰａ１／２以下であることが特に好ましい。|δｐ１－δｐ２|が２．５ＭＰａ１／２超であると、ＣＮＴ分散液を用いて形成される成形体について導電性向上効果を十分に得ることができない。なお、|δｐ１－δｐ２|の下限値は、０ＭＰａ１／２以上であれば特に限定されない。 <|δ p1 −δ p2 |>
In the CNT dispersion of the present invention, as described above, the absolute value of the difference between the polar term δ p1 of the Hansen solubility parameter HSP c of the CNT and the polar term δ p2 of the Hansen solubility parameter HSP d of the dispersion medium is 2. .5 MPa 1/2 or less, preferably 2.0 MPa 1/2 or less, more preferably 1.7 MPa 1/2 or less, and 1.5 MPa 1/2 or less is more preferably 1.1 MPa 1/2 or less, and particularly preferably 0.8 MPa 1/2 or less. If |δ p1 −δ p2 | exceeds 2.5 MPa 1/2 , the effect of improving the electrical conductivity of the compact formed using the CNT dispersion cannot be sufficiently obtained. The lower limit of |δ p1 −δ p2 | is not particularly limited as long as it is 0 MPa 1/2 or more.
＜ハンセン溶解度パラメータの距離Ｒａ＞
　また、本発明のＣＮＴ分散液は、カーボンナノチューブと分散媒とのハンセン溶解度パラメータの距離Ｒａが、４．０ＭＰａ１／２以下であることが好ましく、３．５ＭＰａ１／２以下であることがより好ましく、３．０ＭＰａ１／２以下であることが更に好ましく、２．５ＭＰａ１／２以下であることが一層好ましく、２．０ＭＰａ１／２以下であることが特に好ましい。ハンセン溶解度パラメータの距離Ｒａが４．０ＭＰａ１／２以下であれば、ＣＮＴの分散性向上効果が一層高まるためと推察されるが、成形体の導電性を更に向上させることができる。なお距離Ｒａの下限値は、０ＭＰａ１／２以上であれば特に限定されない。 <Distance R a of Hansen Solubility Parameter>
Further, in the CNT dispersion of the present invention, the distance Ra of the Hansen solubility parameter between the carbon nanotube and the dispersion medium is preferably 4.0 MPa 1/2 or less, more preferably 3.5 MPa 1/2 or less. It is more preferably 3.0 MPa 1/2 or less, even more preferably 2.5 MPa 1/2 or less, and particularly preferably 2.0 MPa 1/2 or less. If the distance R a of the Hansen solubility parameter is 4.0 MPa 1/2 or less, it is presumed that the effect of improving the dispersibility of CNTs is further enhanced, and the electrical conductivity of the compact can be further improved. The lower limit of the distance Ra is not particularly limited as long as it is 0 MPa 1/2 or more.
＜ＣＮＴ分散液の調製方法＞
　ＣＮＴ分散液は、ＣＮＴ及び必要に応じて用いられるその他の成分を、既知の分散処理を用いて分散媒中に分散させることで、調製することができる。このような分散処理としては、例えば超音波処理を好ましく用いることができる。分散処理の際の分散条件（分散時間など）は、適宜設定することができる。 <Method for preparing CNT dispersion>
A CNT dispersion can be prepared by dispersing CNTs and other optional components in a dispersion medium using a known dispersion process. As such dispersion treatment, for example, ultrasonic treatment can be preferably used. Dispersion conditions (dispersion time, etc.) for distributed processing can be set as appropriate.
（炭素膜の製造方法）
　本発明の炭素膜の製造方法は、上述した本発明のＣＮＴ分散液から分散媒を除去して成膜する工程（成膜工程）を含む。本発明のＣＮＴ分散液から形成される炭素膜は、導電性に優れる。炭素膜は、必ずしも分散媒が全て除去されている必要はなく、炭素膜の所期の性状に過度な悪影響を及ぼさない範囲内の量で分散媒が残存していてもよい。
　なお、本発明の炭素膜の製造方法は、成膜工程以外の工程を含んでいてもよい。 (Manufacturing method of carbon film)
The method for producing a carbon film of the present invention includes a step of forming a film by removing the dispersion medium from the CNT dispersion of the present invention described above (film forming step). A carbon film formed from the CNT dispersion of the present invention has excellent conductivity. The dispersion medium does not necessarily have to be completely removed from the carbon film, and the dispersion medium may remain in an amount within a range that does not excessively adversely affect the desired properties of the carbon film.
The method for producing a carbon film of the present invention may include steps other than the film forming step.
＜成膜工程＞
　成膜工程では、例えば下記（Ａ）と（Ｂ）の何れかの方法を用いて、ＣＮＴ分散液から分散媒を除去する。
（Ａ）ＣＮＴ分散液を成膜基材上に塗布した後、塗布したＣＮＴ分散液を乾燥させる方法。
（Ｂ）多孔質の成膜基材を用いてＣＮＴ分散液をろ過し、得られたろ過物を乾燥させる方法。 <Film formation process>
In the film formation step, the dispersion medium is removed from the CNT dispersion using, for example, one of the following methods (A) and (B).
(A) A method of applying a CNT dispersion onto a film-forming substrate and then drying the applied CNT dispersion.
(B) A method of filtering a CNT dispersion liquid using a porous film-forming base material and drying the resulting filtrate.
＜＜成膜基材＞＞
　ここで、成膜基材としては、特に限定されることなく、製造する炭素膜の用途に応じて既知の基材、例えば、樹脂基材、ガラス基材などを挙げることができる。
　樹脂基材としては、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリイミド、ポリフェニレンスルフィド、アラミド、ポリプロピレン、ポリエチレン、ポリ乳酸、ポリ塩化ビニル、ポリカーボネート、ポリメタクリル酸メチル、脂環式アクリル樹脂、シクロオレフィン樹脂、トリアセチルセルロースなどよりなる基材を挙げることができる。
　ガラス基材としては、ソーダガラスよりなる基材を挙げることができる。
　また、上記方法（Ｂ）においてＣＮＴ分散液をろ過する多孔質の成膜基材としては、ろ紙や、セルロース、ニトロセルロース、アルミナ等よりなる多孔質シートを挙げることができる。 <<Deposition base material>>
Here, the film-forming substrate is not particularly limited, and known substrates, such as resin substrates and glass substrates, can be used depending on the application of the carbon film to be produced.
Examples of resin base materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene (PTFE), polyimide, polyphenylene sulfide, aramid, polypropylene, polyethylene, polylactic acid, polyvinyl chloride, polycarbonate, and polymethacrylic acid. Substrates made of methyl, alicyclic acrylic resins, cycloolefin resins, triacetyl cellulose and the like can be mentioned.
Examples of glass substrates include substrates made of soda glass.
Examples of the porous film-forming substrate for filtering the CNT dispersion in the above method (B) include filter paper and porous sheets made of cellulose, nitrocellulose, alumina, or the like.
＜＜塗布＞＞
　上記方法（Ａ）においてＣＮＴ分散液を成膜基材上に塗布する方法としては、公知の塗布方法を採用できる。具体的には、塗布方法としては、ディッピング法、ロールコート法、グラビアコート法、ナイフコート法、エアナイフコート法、ロールナイフコート法、ダイコート法、スクリーン印刷法、スプレーコート法、グラビアオフセット法などを用いることができる。 <<Coating>>
As a method of applying the CNT dispersion onto the film-forming substrate in the above method (A), a known coating method can be employed. Specifically, the coating method includes a dipping method, a roll coating method, a gravure coating method, a knife coating method, an air knife coating method, a roll knife coating method, a die coating method, a screen printing method, a spray coating method, a gravure offset method, and the like. can be used.
＜＜ろ過＞＞
　上記方法（Ｂ）において成膜基材を用いてＣＮＴ分散液をろ過する方法としては、公知のろ過方法を採用できる。具体的には、ろ過方法としては、自然ろ過、減圧ろ過、加圧ろ過、遠心ろ過などを用いることができる。 <<Filtration>>
As a method for filtering the CNT dispersion liquid using the film-forming substrate in the above method (B), a known filtration method can be employed. Specifically, natural filtration, vacuum filtration, pressure filtration, centrifugal filtration, etc. can be used as the filtration method.
＜＜乾燥＞＞
　上記方法（Ａ）において成膜基材上に塗布したＣＮＴ分散液を乾燥する方法、及び上記方法（Ｂ）において得られたろ過物を乾燥する方法としては、公知の乾燥方法を採用できる。乾燥方法としては、熱風乾燥法、真空乾燥法、熱ロール乾燥法、赤外線照射法等が挙げられる。乾燥温度は、特に限定されないが、通常、室温～２００℃、乾燥時間は、特に限定されないが、通常、０．１～１５０分である。 <<Dry>>
As the method for drying the CNT dispersion applied onto the film-forming substrate in the above method (A) and the method for drying the filtrate obtained in the above method (B), known drying methods can be employed. Examples of the drying method include hot air drying, vacuum drying, hot roll drying, and infrared irradiation. The drying temperature is not particularly limited, but usually room temperature to 200° C., and the drying time is not particularly limited, but is usually 0.1 to 150 minutes.
＜その他の工程＞
　本発明の炭素膜の製造方法が任意に含むその他の工程としては、特に限定されないが、例えば、成膜した炭素膜をプレス加工して密度を高める工程（プレス工程）などが挙げられる。 <Other processes>
Other steps optionally included in the method for producing a carbon film of the present invention are not particularly limited, but include, for example, a step of press processing the formed carbon film to increase its density (press step).
（エラストマー混合液）
　本発明のエラストマー混合液は、エラストマーと、上述した本発明のＣＮＴ分散液とを含む。換言すると、本発明のエラストマー混合液は、エラストマーと、上述したＣＮＴと、上述した分散媒を含有する液状媒体とを少なくとも含み、任意に、エラストマー、ＣＮＴ、及び液状媒体以外の成分（その他の成分）を含む。
　そして、本発明のエラストマー混合液を用いれば、導電性に優れるエラストマー成形体を作製することができる。 (elastomer mixture)
The elastomer mixture of the present invention contains an elastomer and the CNT dispersion of the present invention described above. In other words, the elastomer mixture of the present invention contains at least the elastomer, the CNTs described above, and the liquid medium containing the dispersion medium described above, and optionally components other than the elastomer, CNTs, and the liquid medium (other components )including.
By using the elastomer liquid mixture of the present invention, an elastomer molded article having excellent conductivity can be produced.
＜エラストマー＞
　エラストマー混合液が含むエラストマーとしては、特に限定されることなく、例えば、任意のゴム、樹脂又はそれらの混合物を用いることができる。
　具体的には、ゴムとしては、特に限定されることなく、例えば、天然ゴム；フッ化ビニリデン系ゴム（ＦＫＭ）、テトラフルオロエチレン－プロピレン系ゴム（ＦＥＰＭ）、テトラフルオロエチレン－パープルオロビニルエーテル系ゴム（ＦＦＫＭ）などのフッ素ゴム；ブタジエンゴム（ＢＲ）、イソプレンゴム（ＩＲ）、スチレン－ブタジエンゴム（ＳＢＲ）、水素化スチレン－ブタジエンゴム（Ｈ－ＳＢＲ）、ニトリルゴム（ＮＢＲ）、水素化ニトリルゴム（Ｈ－ＮＢＲ）などのジエンゴム；シリコーンゴム；等が挙げられる。
　また、樹脂としては、特に限定されることなく、例えば、ポリテトラフルオロエチレン（ＰＴＦＥ）などのフッ素樹脂；ポリメタクリル酸メチル（ＰＭＭＡ）などのアクリル樹脂；ポリスチレン（ＰＳ）；ポリカーボネート（ＰＣ）；等が挙げられる。 <Elastomer>
The elastomer contained in the elastomer mixture 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.
　エラストマーの種類は、エラストマー混合液を用いて得られるエラストマー成形体の用途等に応じて適宜選択すればよい。なお、エラストマーは、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 The type of elastomer may be appropriately selected according to the application of the elastomer molded article obtained using the elastomer mixture. In addition, an elastomer may be used individually by 1 type, and may be used in combination of 2 or more type.
　エラストマー混合液中におけるエラストマーとＣＮＴの比率は特に限定されないが、混合液中におけるＣＮＴの含有量が、エラストマー１００質量部当たり、０．１質量部以上であることが好ましく、１質量部以上であることがより好ましく、２質量部以上であることが更に好ましく、１０質量部以下であることが好ましく、８質量部以下であることがより好ましく、７質量部以下であることが更に好ましい。エラストマー混合液中におけるＣＮＴの含有量が上記範囲内であれば、得られるエラストマー成形体の導電性を十分に向上させることができる。 The ratio of the elastomer to CNTs in the elastomer mixed solution is not particularly limited, but the content of CNTs in the mixed solution is preferably 0.1 parts by mass or more, and 1 part by mass or more per 100 parts by mass of the elastomer. more preferably 2 parts by mass or more, preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7 parts by mass or less. If the content of CNTs in the elastomer mixed solution is within the above range, the electrical conductivity of the obtained elastomer molding can be sufficiently improved.
＜ＣＮＴ＞
　エラストマー混合液が含むＣＮＴは、上述した本発明のＣＮＴ分散液に含まれていたものである。 <CNT>
The CNTs contained in the elastomer mixture were those contained in the CNT dispersion of the present invention described above.
＜液状媒体＞
　エラストマー混合液が含む液状媒体は、上述した本発明のＣＮＴ分散液に含まれていた分散媒を少なくとも含有する。液状媒体には、ＣＮＴ分散液に由来しない水又は有機溶媒（例えば、ＣＮＴ分散液とエラストマーの混合に先んじてエラストマーを溶解させるために用いた有機溶媒）が含まれていてもよい。 <Liquid medium>
The liquid medium contained in the elastomer mixture contains at least the dispersion medium contained in the CNT dispersion of the present invention described above. The liquid medium may include water or organic solvents not derived from the CNT dispersion (eg, the organic solvent used to dissolve the elastomer prior to mixing the CNT dispersion with the elastomer).
＜その他の成分＞
　上述したエラストマー、ＣＮＴ及び液状媒体以外にエラストマー混合液が含み得る成分としては、エラストマー成形体の調製に用いられる既知の添加剤が挙げられる。なお、その他の成分は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 <Other ingredients>
In addition to the elastomer, CNTs, and liquid medium described above, the components that the elastomer mixture may contain include known additives used in the preparation of elastomer moldings. In addition, another component may be used individually by 1 type, and may be used in combination of 2 or more type.
＜エラストマー混合液の調製方法＞
　エラストマー混合液は、ＣＮＴ分散液とエラストマーを既知の混合方法で混合して調製することができる。混合条件（混合時間など）は、適宜設定することができる。なお、エラストマーは、既知の有機溶媒に溶解させた状態で、ＣＮＴ分散液と混合することが好ましい。エラストマーの溶解に用いる有機溶媒は、エラストマーの種類に応じて適宜選択することができる。 <Method for preparing elastomer mixture>
The elastomer mixture can be prepared by mixing the CNT dispersion and the elastomer by a known mixing method. Mixing conditions (mixing time, etc.) can be appropriately set. The elastomer is preferably dissolved in a known organic solvent and then mixed with the CNT dispersion. The organic solvent used for dissolving the elastomer can be appropriately selected according to the type of elastomer.
（複合材料の製造方法）
　本発明の複合材料の製造方法は、上述した本発明のエラストマー混合液から分散媒を除去する工程（分散媒除去工程）を含む。上述のようにして形成される複合材料はエラストマー中にＣＮＴが良好に分散しうり、当該複合材料を用いれば導電性に優れるエラストマー成形体を得ることができる。なお複合材料は、必ずしも分散媒が全て除去されている必要はなく、複合材料の所期の性状に過度な悪影響を及ぼさない範囲内の量で分散媒が残存していてもよい。
　なお、本発明の複合材料の製造方法は、分散媒除去工程以外の工程（その他の工程）を含んでいてもよい。 (Manufacturing method of composite material)
The manufacturing method of the composite material of the present invention includes a step of removing the dispersion medium from the elastomer mixed liquid of the present invention (dispersion medium removal step). In the composite material formed as described above, CNTs can be well dispersed in the elastomer, and the use of the composite material makes it possible to obtain an elastomer molded article having excellent conductivity. The composite material does not necessarily have to have all the dispersion medium removed, and the dispersion medium may remain in an amount within a range that does not excessively adversely affect the desired properties of the composite material.
In addition, the manufacturing method of the composite material of the present invention may include steps (other steps) other than the dispersion medium removing step.
＜分散媒除去工程＞
　分散媒除去工程において、エラストマー混合液から分散媒を除去する方法は特に限定されず、既知の方法を用いることができる。
　例えば、エラストマー混合液を成膜基材上に塗布した後、塗布したエラストマー混合液を乾燥することで分散媒を除去することができる。当該方法において用いる成膜基材、並びに塗布及び乾燥の方法は、「炭素膜の製造方法」の項で上述した（Ａ）の方法と同様のものを用いることができる。
　また分散媒除去工程に際し、得られる複合材料を、シート状などの所期の形状に成形してもよい。すなわち本発明の複合材料の製造方法により得られる複合材料を、そのままエラストマー成形体として用いることもできる。
　なおエラストマー混合液に、ＣＮＴ分散液に由来する分散媒以外の水及び／又は有機溶媒が含まれる場合、当該水及び／又は有機溶媒についても、分散媒除去工程で除去することが好ましい。そしてこれらの水及び／又は有機溶媒は、得られる複合材料において、分散媒同様、全て除去されている必要はなく、複合材料の所期の性状に過度な悪影響を及ぼさない範囲内の量で残存していてもよい。 <Dispersion medium removal step>
In the dispersion medium removing step, the method for removing the dispersion medium from the elastomer mixture is not particularly limited, and known methods can be used.
For example, the dispersion medium can be removed by applying the elastomer mixed liquid onto the film-forming substrate and then drying the applied elastomer mixed liquid. The film-forming substrate and the method of coating and drying used in this method can be the same as the method (A) described above in the section “Method for producing carbon film”.
Further, in the dispersion medium removing step, the resulting composite material may be formed into a desired shape such as a sheet. That is, the composite material obtained by the method for producing a composite material of the present invention can be used as it is as an elastomer molding.
When the elastomer mixture contains water and/or organic solvent other than the dispersion medium derived from the CNT dispersion, it is preferable to remove the water and/or organic solvent in the dispersion medium removal step. These water and/or organic solvents, like the dispersion medium, do not need to be completely removed in the composite material obtained, and remain in an amount within a range that does not excessively adversely affect the desired properties of the composite material. You may have
＜その他の工程＞
　本発明の複合材料の製造方法が任意に含むその他の工程としては、特に限定されないが、例えば、分散媒除去工程を経て得られた複合材料に、更に添加剤を添加する工程などが挙げられる。例えば、添加剤として後述の架橋剤を用いれば、架橋剤を含む複合材料（架橋性複合材料）を得ることができる。 <Other processes>
Other steps optionally included in the method for producing a composite material of the present invention are not particularly limited, but include, for example, a step of adding an additive to the composite material obtained through the dispersion medium removal step. For example, if a cross-linking agent described later is used as an additive, a composite material (crosslinkable composite material) containing the cross-linking agent can be obtained.
（エラストマー成形体の製造方法）
　本発明のエラストマー成形体の製造方法は、上述した本発明のエラストマー混合液から分散媒を除去して複合材料を得る工程（分散媒除去工程）と、分散媒除去工程を経て得られた複合材料に架橋剤を添加する工程（架橋剤添加工程）と、架橋剤添加工程を経て得られた架橋性複合材料を架橋してエラストマー成形体を得る工程（架橋工程）とを含む。上述のようにして形成されるエラストマー成形体は、架橋したエラストマーのマトリックス中でＣＮＴが良好に分散しうり、優れた導電性を発揮することができる。
　なお、複合材料及びエラストマー成形体は、必ずしも分散媒（及び必要に応じてエラストマー混合液に含まれる、ＣＮＴ分散液に由来する分散媒以外の水及び／又は有機溶媒）が全て除去されている必要はなく、複合材料及びエラストマー成形体の所期の性状に過度な悪影響を及ぼさない範囲内の量で残存していてもよい。
　また、本発明のエラストマー成形体の製造方法は、分散媒除去工程、架橋剤添加工程、及び架橋工程以外の工程（その他の工程）を含んでいてもよい。このようなその他の工程としては特に限定されず、所期のエラストマー成形体を得るための任意の工程を採用することができる。 (Manufacturing method of elastomer molding)
The method for producing an elastomer molded article of the present invention includes a step of removing the dispersion medium from the elastomer mixture of the present invention to obtain a composite material (dispersion medium removal step), and a composite material obtained through the dispersion medium removal step. and a step of cross-linking the cross-linkable composite material obtained through the cross-linking agent addition step to obtain an elastomer molded product (cross-linking step). In the elastomer molded article formed as described above, the CNTs can be satisfactorily dispersed in the crosslinked elastomer matrix, and excellent electrical conductivity can be exhibited.
It should be noted that the composite material and the elastomer molded article must be completely free of the dispersion medium (and, if necessary, the water and/or organic solvent other than the dispersion medium derived from the CNT dispersion, which are contained in the elastomer mixed liquid). However, it may remain in an amount that does not unduly adversely affect the intended properties of the composite material and elastomeric molded article.
In addition, the method for producing an elastomer molded article of the present invention may include steps (other steps) other than the dispersion medium removal step, the cross-linking agent addition step, and the cross-linking step. Such other steps are not particularly limited, and any steps for obtaining the desired elastomer molded article can be adopted.
＜分散媒除去工程＞
　分散媒除去工程では、「複合材料の製造方法」の項で上述した分散媒除去工程と同様にしてエラストマー混合液から分散媒（及び必要に応じてエラストマー混合液に含まれる、ＣＮＴ分散液に由来する分散媒以外の水及び／又は有機溶媒）を除去し、複合材料を得る。 <Dispersion medium removal step>
In the dispersion medium removal step, in the same manner as in the dispersion medium removal step described above in the section "Manufacturing method of composite material", the dispersion medium is removed from the elastomer mixture (and, if necessary, the CNT dispersion contained in the elastomer mixture) Water and/or organic solvent other than the dispersion medium) are removed to obtain a composite material.
＜架橋剤添加工程＞
　架橋剤添加工程では、分散媒除去工程で得られた複合材料に架橋剤を添加する。
　架橋剤としては、エラストマーを架橋可能な既知の架橋剤を用いることができる。このような架橋剤としては、例えば、硫黄系架橋剤、パーオキサイド系架橋剤、ビスフェノール系架橋剤、ジアミン系架橋剤が挙げられる。
　なお、架橋剤は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。また複合材料に添加する架橋剤の量は、特に限定されず、エラストマー及び架橋剤の種類に応じて適宜設定することができる。
　そして、架橋剤を複合材料に添加する方法は、特に限定されない。例えば複合材料と架橋剤を既知の混練方法を用いて混練することで、エラストマーと、ＣＮＴと、架橋剤とが良好に混ざった架橋性複合材料を得ることができる。 <Step of adding cross-linking agent>
In the cross-linking agent adding step, a cross-linking agent is added to the composite material obtained in the dispersion medium removing step.
As the cross-linking agent, a known cross-linking agent capable of cross-linking the elastomer 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 may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, the amount of the cross-linking agent added to the composite material is not particularly limited, and can be appropriately set according to the types of the elastomer and the cross-linking agent.
And the method of adding the cross-linking agent to the composite material is not particularly limited. For example, by kneading the composite material and the cross-linking agent using a known kneading method, it is possible to obtain a cross-linkable composite material in which the elastomer, CNTs and the cross-linking agent are well mixed.
＜架橋工程＞
　架橋工程では、架橋剤添加工程で得られた架橋性複合材料（架橋剤を含む複合材料）を架橋する。架橋性複合材料を架橋する際の条件（架橋時間、架橋温度等）は、架橋性複合材料に含まれるエラストマー及び架橋剤の、種類及び／又は含有量などに応じて適宜設定することができる。
　なお、架橋性複合材料を予め所期の形状を有する金型に入れた状態で架橋を行い、架橋反応が完了すると当時に所期の形状を有するエラストマー成形体を得てもよいし、架橋反応が完了した後に得られる架橋体を任意の手法で所期の形状に成形して、エラストマー成形体を得てもよい。 <Crosslinking step>
In the cross-linking step, the cross-linkable composite material (composite material containing the cross-linking agent) obtained in the cross-linking agent addition step is cross-linked. The conditions for crosslinking the crosslinkable composite material (crosslinking time, crosslinking temperature, etc.) can be appropriately set according to the type and/or content of the elastomer and crosslinking agent contained in the crosslinkable composite material.
The crosslinkable composite material may be placed in a mold having a desired shape in advance and then crosslinked, and when the crosslinking reaction is completed, an elastomer molded body having the desired shape may be obtained. The crosslinked product obtained after the step is completed may be molded into a desired shape by any method to obtain an elastomer molded product.
　以下、本発明について実施例を用いて更に詳細に説明するが、本発明はこれら実施例に限定されるものではない。
　なお、実施例及び比較例において、カーボンナノチューブ及び分散媒のハンセン溶解度パラメータ、炭素膜及びエラストマー成形体の体積抵抗率は、それぞれ以下のように特定又は測定した。
　また、実施例において、ハンセン溶解度パラメータの分散項、極性項、水素結合項の単位は、特に断らない限り「ＭＰａ１／２」である。 EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.
In the examples and comparative examples, the Hansen solubility parameters of the carbon nanotubes and the dispersion medium, and the volume resistivities of the carbon films and the elastomer moldings were specified or measured as follows.
In the examples, the units of the dispersion term, polar term, and hydrogen bond term of the Hansen Solubility Parameters are "MPa 1/2 " unless otherwise specified.
＜ハンセン溶解度パラメータ＞
＜＜カーボンナノチューブのＨＳＰｃ＞＞
　カーボンナノチューブのハンセン溶解度パラメータ（ＨＳＰｃ）については、Ｈａｎｓｅｎ球法を用いて、極性項δｐ１、分散項δｄ１、及び水素結合項δｈ１を求めた。具体的には、対象となるカーボンナノチューブ０．００３ｇを、溶解度パラメータが既知の溶媒５．９９７ｇに混合し、卓上型超音波洗浄機（ブランソン社製、製品名「ブランソニック５５１０」）を用いて、２５分間超音波処理を行った。得られたカーボンナノチューブ分散液を、遠心分離機（フナコシ社製、製品名「Ａｒｇｏｓ　ｆｌａｘｉｆｕｇｅ」）を用いて、回転数９２００ｒｐｍで５分間遠心分離させ、目視で上澄みの溶液に色がついているか判断した。色がついていた場合を溶解する溶媒と決め、色がついていなかった場合（即ち、溶媒単独と色が変わらなかった場合）を溶解しない溶媒と決めた。次いで、溶解性試験の結果をコンピュータソフトウェア（Ｈａｎｓｅｎ　Ｓｏｌｕｂｉｌｉｔｙ　Ｐａｒａｍｅｔｅｒｓ　ｉｎ　Ｐｒａｃｔｉｃｅ（ＨＳＰｉＰ））を用いることによって、溶解度パラメータ（δｐ、δｄ、δｈ）の三次元空間にプロットし、溶解する溶媒の座標を含み、溶解しない溶媒の座標を含まない球（Ｈａｎｓｅｎ球）を求めた。この球の中心座標を、カーボンナノチューブのハンセン溶解度パラメータＨＳＰｃ（δｐ１、δｄ１、δｈ１）とした。なお溶媒は、溶解する溶媒が４種類以上、溶解する溶媒と溶解しない溶媒との合計数が２０種類以上となるよう選定した。
＜＜分散媒のＨＳＰｄ＞＞
　分散媒のハンセン溶解度パラメータ（ＨＳＰｄ）については、極性項δｐ２、分散項δｄ２、及び水素結合項δｈ２を下記の文献に記載されている定義及び計算方法により特定した。Ｃｈａｒｌｅｓ　Ｍ．　Ｈａｎｓｅｎ著、「Ｈａｎｓｅｎ　Ｓｏｌｕｂｉｌｉｔｙ　Ｐａｒａｍｅｔｅｒｓ：　Ａ　Ｕｓｅｒｓ　Ｈａｎｄｂｏｏｋ」、ＣＲＣプレス、２００７年。
　なお、ハンセン溶解度パラメータの文献値が未知の物質については、コンピュータソフトウェア（Ｈａｎｓｅｎ　Ｓｏｌｕｂｉｌｉｔｙ　Ｐａｒａｍｅｔｅｒｓ　ｉｎ　Ｐｒａｃｔｉｃｅ（ＨＳＰｉＰ））を用いることによって、その化学構造から簡便にハンセン溶解度パラメータを推算することができる。
　例えば、ＨＳＰｉＰバージョン３を用い、データベースに登録されている化合物についてはその値を用い、登録されていない化合物については推算値を用いればよい。
　また、分散媒として複数種の成分（例えば２種以上の有機溶媒）を組み合わせて用いる場合は、各成分それぞれの極性項、分散項、及び水素結合項について、各成分の混合比率を考慮した体積加重平均をとり、それらの値を分散媒の極性項δｐ２、分散項δｄ２、及び水素結合項δｈ２として用いることができる。
＜体積抵抗率＞
　低抵抗率計（三菱化学アナリテック社製、製品名「ロレスタ－ＧＸ　ＭＣＰ－Ｔ７００」、プローブ：ＰＳＰ）を用いて、得られた成形体（炭素膜、エラストマー成形体）の体積抵抗率を５点、測定箇所を変えて測定した。そして、５点の測定値から平均値を求め、当該平均値を成形体の体積抵抗率とした。体積抵抗率の値が小さいほど、成形体が導電性に優れると言える。 <Hansen Solubility Parameter>
<< HSP c of carbon nanotubes >>
For the Hansen solubility parameter (HSP c ) of carbon nanotubes, the Hansen sphere method was used to obtain the polar term δ p1 , the dispersion term δ d1 , and the hydrogen bonding term δ h1 . Specifically, 0.003 g of the target carbon nanotube is mixed with 5.997 g of a solvent with a known solubility parameter, and a desktop ultrasonic cleaner (manufactured by Branson, product name “Bransonic 5510”) is used. , sonicated for 25 minutes. The resulting carbon nanotube dispersion was centrifuged at 9200 rpm for 5 minutes using a centrifuge (manufactured by Funakoshi Co., Ltd., product name “Argos flaxifuge”), and it was visually determined whether the supernatant solution was colored. . If it was colored, it was determined to be a soluble solvent, and if it was not colored (that is, the color did not change from that of the solvent alone), it was determined to be a non-dissolving solvent. The results of the solubility test are then plotted in the three-dimensional space of the solubility parameters (δ p , δ d , δ h ) by using computer software (Hansen Solubility Parameters in Practice (HSPiP)) and the coordinates of the dissolving solvent A sphere (Hansen sphere) containing the coordinates of the undissolved solvent was determined. The central coordinates of this sphere were taken as the Hansen solubility parameters HSP c (δ p1 , δ d1 , δ h1 ) of carbon nanotubes. The solvents were selected so that the number of soluble solvents was 4 or more, and the total number of soluble and insoluble solvents was 20 or more.
<< HSP d of dispersion medium >>
Regarding the Hansen Solubility Parameter (HSP d ) of the dispersion medium, the polar term δ p2 , the dispersion term δ d2 , and the hydrogen bonding term δ h2 were specified by the definition and calculation method described in the following literature. Charles M. Hansen, "Hansen Solubility Parameters: A Users Handbook," CRC Press, 2007.
For substances with unknown literature values for Hansen Solubility Parameters, the Hansen Solubility Parameters can be easily estimated from the chemical structure by using computer software (Hansen Solubility Parameters in Practice (HSPiP)).
For example, using HSPiP version 3, the values may be used for compounds registered in the database, and the estimated values may be used for compounds not registered.
In addition, when using a combination of a plurality of components (for example, two or more organic solvents) as a dispersion medium, the polar term, dispersion term, and hydrogen bonding term of each component are calculated in consideration of the mixing ratio of each component. Taking a weighted average, these values can be used as the polar term δ p2 , the dispersion term δ d2 , and the hydrogen bonding term δ h2 of the dispersion medium.
<Volume resistivity>
Using a low resistivity meter (manufactured by Mitsubishi Chemical Analytic Tech, product name “Loresta-GX MCP-T700”, probe: PSP), the volume resistivity of the obtained molded body (carbon membrane, elastomer molded body) was measured as 5. Measured by changing points and measuring points. Then, an average value was obtained from the measured values at five points, and the average value was taken as the volume resistivity of the molded body. It can be said that the smaller the value of the volume resistivity, the better the electrical conductivity of the molded article.
（実験Ａ：炭素膜）
＜実施例１＞
　分散媒としてのｐ－クロロトルエン（東京化成社製、ハンセン溶解度パラメータＨＳＰｄ：δｄ２＝１９．１、δｐ２＝６．２、δｈ２＝２．６）５．９９７ｇに、単層カーボンナノチューブであるＣＮＴ１（日本ゼオン社製、製品名「ＺＥＯＮＡＮＯ　ＳＧ１０１」、平均直径：３．４ｎｍ、ＢＥＴ比表面積：１４６８ｍ２／ｇ、ｔ－プロットは上に凸、ハンセン溶解度パラメータＨＳＰｃ：δｄ１＝１８．８、δｐ１＝５．５、δｈ１＝３．９）０．００３ｇを加え、プローブ型超音波装置（三井電機精機社製、製品名「ＵＸ３００」）を用いて、出力３００Ｗ、周波数２００００ｋＨｚで２５分間照射を行うことにより、ＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度１５０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を成膜基材から剥離して、厚み２３μｍの炭素膜を得た。得られた炭素膜について、体積抵抗率を測定した。また体積抵抗率の測定値を、後述の比較例１で得られた炭素膜の体積抵抗率を１００（基準値）として指数値に変換した。そしてＣＮＴ分散液について|δｐ１－δｐ２|を算出し、また式（Ｉ）を用いてカーボンナノチューブと分散媒とのハンセン溶解度パラメータの距離Ｒａを算出した。これらの結果を何れも表１に示す。 (Experiment A: carbon film)
<Example 1>
5.997 g of p-chlorotoluene (manufactured by Tokyo Chemical Industry Co., Ltd., Hansen solubility parameter HSP d : δ d2 = 19.1, δ p2 = 6.2, δ h2 = 2.6) as a dispersion medium, single-walled carbon nanotubes CNT1 (manufactured by Zeon Corporation, product name “ZEONANO SG101”, average diameter: 3.4 nm, BET specific surface area: 1468 m 2 /g, t-plot is upwardly convex, Hansen solubility parameter HSP c : δ d1 = 18 .8, δ p1 =5.5, δ h1 =3.9) 0.003 g was added, and a probe-type ultrasonic device (manufactured by Mitsui Electric Seiki Co., Ltd., product name “UX300”) was used to generate an output of 300 W and a frequency of 20000 kHz. A CNT dispersion was obtained by performing irradiation for 25 minutes at .
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film forming substrate to obtain a carbon film having a thickness of 23 μm. The volume resistivity of the obtained carbon film was measured. Further, the measured value of the volume resistivity was converted into an index value with the volume resistivity of the carbon film obtained in Comparative Example 1 described later as 100 (reference value). Then, |δ p1 −δ p2 | was calculated for the CNT dispersion, and the distance Ra of the Hansen solubility parameter between the carbon nanotubes and the dispersion medium was calculated using the formula (I). All these results are shown in Table 1.
＜比較例１＞
　分散媒として、ｐ－クロロトルエンに代えてメチルエチルケトン（ハンセン溶解度パラメータＨＳＰｄ：δｄ２＝１６．０、δｐ２＝９．０、δｈ２＝５．１）を用いた以外は、実施例１と同様にしてＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度６０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を成膜基材から剥離して、厚み２３μｍの炭素膜を得た。そして、実施例１と同様にして各種評価及び測定を行った。結果を表１に示す。 <Comparative Example 1>
As the dispersion medium, instead of p-chlorotoluene, methyl ethyl ketone (Hansen solubility parameter HSP d : δ d2 = 16.0, δ p2 = 9.0, δ h2 = 5.1) was used. A CNT dispersion was obtained in the same manner.
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 60° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film forming substrate to obtain a carbon film having a thickness of 23 μm. Various evaluations and measurements were performed in the same manner as in Example 1. Table 1 shows the results.
（比較例２）
　分散媒として、ｐ－クロロトルエンに代えて１，２，４－トリメチルベンゼン（ハンセン溶解度パラメータＨＳＰｄ：δｄ２＝１７．９、δｐ２＝２．９、δｈ２＝３．１）を用いた以外は、実施例１と同様にしてＣＮＴ分散液及び炭素膜を得た。そして、実施例１と同様にして各種評価及び測定を行った。結果を表１に示す。 (Comparative example 2)
As a dispersion medium, 1,2,4-trimethylbenzene (Hansen solubility parameter HSP d : δ d2 =17.9, δ p2 =2.9, δ h2 =3.1) was used instead of p-chlorotoluene. Except for this, a CNT dispersion and a carbon film were obtained in the same manner as in Example 1. Various evaluations and measurements were performed in the same manner as in Example 1. Table 1 shows the results.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１によれば、実施例１と、実施例１とは同一のＣＮＴを用いる一方で分散媒が異なる比較例１～２とを比較すると、|δｐ１－δｐ２|が２．５ＭＰａ１／２以下である実施例１のＣＮＴ分散液を用いて得られた炭素膜が、|δｐ１－δｐ２|が２．５ＭＰａ１／２超である比較例１～２のＣＮＴ分散液を用いて得られた炭素膜に比して体積抵抗率が低い。この比較により、実施例１における炭素膜の導電性向上効果を確認できる。 According to Table 1, when comparing Example 1 with Comparative Examples 1 and 2 that use the same CNTs as in Example 1 but have different dispersion media, |δ p1 −δ p2 | is 2.5 MPa 1/ 2 or less using the CNT dispersions of Comparative Examples 1 and 2 in which |δ p1 −δ p2 | is greater than 2.5 MPa 1/2 The volume resistivity is lower than that of the obtained carbon film. By this comparison, the effect of improving the electrical conductivity of the carbon film in Example 1 can be confirmed.
（実験Ｂ：炭素膜）
＜実施例２＞
　分散媒としてのアセトフェノン（ハンセン溶解度パラメータＨＳＰｄ：δｄ２＝１８．８、δｐ２＝９．０、δｈ２＝４．０）５．９９７ｇに、単層カーボンナノチューブであるＣＮＴ２（ＯＣＳｉＡｌ社製、製品名「ＴＵＢＡＬＬ」、平均直径：２．０ｎｍ、ＢＥＴ比表面積：３９５ｍ２／ｇ、ｔ－プロットは上に凸、ハンセン溶解度パラメータＨＳＰｃ：δｄ１＝１８．０、δｐ１＝１０．１、δｈ１＝６．６）０．００３ｇを加え、プローブ型超音波装置（三井電機精機社製、製品名「ＵＸ３００」）を用いて、出力３００Ｗ、周波数２００００ｋＨｚで２５分間照射を行うことにより、ＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度１８０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を成膜基材から剥離して、厚み２２μｍの炭素膜を得た。得られた炭素膜について、体積抵抗率を測定した。また体積抵抗率の測定値を、後述の比較例４で得られた炭素膜の体積抵抗率を１００（基準値）として指数値に変換した。そしてＣＮＴ分散液について|δｐ１－δｐ２|を算出し、また式（Ｉ）を用いてカーボンナノチューブと分散媒とのハンセン溶解度パラメータの距離Ｒａを算出した。これらの結果を何れも表２に示す。 (Experiment B: carbon film)
<Example 2>
5.997 g of acetophenone (Hansen solubility parameter HSP d : δ d2 =18.8, δ p2 =9.0, δ h2 =4.0) as a dispersion medium, and CNT2, which is a single-walled carbon nanotube (manufactured by OCSiAl, Product name "TUBALL", average diameter: 2.0 nm, BET specific surface area: 395 m 2 /g, t-plot is upward convex, Hansen solubility parameter HSP c : δ d1 = 18.0, δ p1 = 10.1, δ h1 = 6.6) 0.003 g is added, and a probe-type ultrasonic device (manufactured by Mitsui Electric Seiki Co., Ltd., product name “UX300”) is used to irradiate for 25 minutes at an output of 300 W and a frequency of 20000 kHz to obtain CNTs. A dispersion was obtained.
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 180° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 22 μm. The volume resistivity of the obtained carbon film was measured. Further, the measured value of the volume resistivity was converted into an index value with the volume resistivity of the carbon film obtained in Comparative Example 4 described later as 100 (reference value). Then, |δ p1 −δ p2 | was calculated for the CNT dispersion, and the distance Ra of the Hansen solubility parameter between the carbon nanotubes and the dispersion medium was calculated using the formula (I). All these results are shown in Table 2.
＜実施例３＞
　分散媒として、アセトフェノンに代えてメチルエチルケトンを用いた以外は、実施例２と同様にしてＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度６０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を成膜基材から剥離して、厚み４０μｍの炭素膜を得た。そして、実施例２と同様にして各種評価及び測定を行った。結果を表２に示す。 <Example 3>
A CNT dispersion was obtained in the same manner as in Example 2, except that methyl ethyl ketone was used as the dispersion medium instead of acetophenone.
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 60° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 40 μm. Various evaluations and measurements were performed in the same manner as in Example 2. Table 2 shows the results.
＜実施例４＞
　分散媒として、アセトフェノンに代えてシクロヘキサノン（ハンセン溶解度パラメータＨＳＰｄ：δｄ２＝１７．８、δｐ２＝８．４、δｈ２＝５．１）を用いた以外は、実施例２と同様にしてＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度１４０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を成膜基材から剥離して、厚み４６μｍの炭素膜を得た。そして、実施例２と同様にして各種評価及び測定を行った。結果を表２に示す。 <Example 4>
In the same manner as in Example 2, except that cyclohexanone (Hansen solubility parameter HSP d : δ d2 =17.8, δ p2 =8.4, δ h2 =5.1) was used instead of acetophenone as the dispersion medium. A CNT dispersion was obtained.
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 140° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 46 μm. Various evaluations and measurements were performed in the same manner as in Example 2. Table 2 shows the results.
＜比較例３＞
　分散媒として、アセトフェノンに代えて１，２，４－トリメチルベンゼンを用いた以外は、実施例２と同様にしてＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度１５０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を成膜基材から剥離して、厚み５３μｍの炭素膜を得た。そして、実施例２と同様にして各種評価及び測定を行った。結果を表２に示す。 <Comparative Example 3>
A CNT dispersion was obtained in the same manner as in Example 2, except that 1,2,4-trimethylbenzene was used as the dispersion medium instead of acetophenone.
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film forming substrate to obtain a carbon film having a thickness of 53 μm. Various evaluations and measurements were performed in the same manner as in Example 2. Table 2 shows the results.
＜比較例４＞
　分散媒として、アセトフェノンに代えてｐ－クロロトルエンを用いた以外は、実施例２と同様にしてＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度１５０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を成膜基材から剥離して、厚み６４μｍの炭素膜を得た。そして、実施例２と同様にして各種評価及び測定を行った。結果を表２に示す。 <Comparative Example 4>
A CNT dispersion was obtained in the same manner as in Example 2, except that p-chlorotoluene was used as the dispersion medium instead of acetophenone.
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 64 μm. Various evaluations and measurements were performed in the same manner as in Example 2. Table 2 shows the results.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２によれば、実施例２～４と、実施例２～４とは同一のＣＮＴを用いる一方で分散媒が異なる比較例３～４とを比較すると、|δｐ１－δｐ２|が２．５ＭＰａ１／２以下である実施例２～４のＣＮＴ分散液を用いて得られた炭素膜が、|δｐ１－δｐ２|が２．５ＭＰａ１／２超である比較例３～４のＣＮＴ分散液を用いて得られた炭素膜に比して体積抵抗率が低い。この比較により、実施例２～４における炭素膜の導電性向上効果を確認できる。 According to Table 2, when comparing Examples 2 to 4 with Comparative Examples 3 to 4 using the same CNTs as in Examples 2 to 4 but using different dispersion media, |δ p1 −δ p2 | The carbon films obtained using the CNT dispersions of Examples 2 to 4, which are 5 MPa 1/2 or less, are the carbon films of Comparative Examples 3 to 4, in which |δ p1 −δ p2 | The volume resistivity is lower than that of a carbon film obtained using a CNT dispersion. By this comparison, the effect of improving the electrical conductivity of the carbon films in Examples 2-4 can be confirmed.
（実験Ｃ：炭素膜）
＜実施例５＞
　分散媒としてのアセトフェノン５．９９７ｇに、単層カーボンナノチューブであるＣＮＴ３（名城ナノカーボン社製、製品名「ＥＣ１．５」、平均直径：２．２ｎｍ、ＢＥＴ比表面積：４７０ｍ２／ｇ、ｔ－プロットは上に凸、ハンセン溶解度パラメータＨＳＰｃ：δｄ１＝１８．７、δｐ１＝７．７、δｈ１＝４．０）０．００３ｇを加え、プローブ型超音波装置（三井電機精機社製、製品名「ＵＸ３００」）を用いて、出力３００Ｗ、周波数２００００ｋＨｚで２５分間照射を行うことにより、ＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度１８０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を成膜基材から剥離して、厚み２２μｍの炭素膜を得た。得られた炭素膜について、体積抵抗率を測定した。また体積抵抗率の測定値を、後述の比較例５で得られた炭素膜の体積抵抗率を１００（基準値）として指数値に変換した。そしてＣＮＴ分散液について|δｐ１－δｐ２|を算出し、また式（Ｉ）を用いてカーボンナノチューブと分散媒とのハンセン溶解度パラメータの距離Ｒａを算出した。これらの結果を何れも表３に示す。 (Experiment C: carbon film)
<Example 5>
To 5.997 g of acetophenone as a dispersion medium, CNT3, which is a single-walled carbon nanotube (manufactured by Meijo Nanocarbon Co., Ltd., product name “EC1.5”, average diameter: 2.2 nm, BET specific surface area: 470 m 2 /g, t- The plot is upward convex, Hansen solubility parameter HSP c : δ d1 = 18.7, δ p1 = 7.7, δ h1 = 4.0) 0.003 g was added, and a probe-type ultrasonic device (manufactured by Mitsui Electric Seiki Co., Ltd. , product name “UX300”), a CNT dispersion was obtained by performing irradiation for 25 minutes at an output of 300 W and a frequency of 20000 kHz.
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 180° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the film-forming substrate to obtain a carbon film having a thickness of 22 μm. The volume resistivity of the obtained carbon film was measured. Further, the measured value of the volume resistivity was converted into an index value with the volume resistivity of the carbon film obtained in Comparative Example 5 described later as 100 (reference value). Then, |δ p1 −δ p2 | was calculated for the CNT dispersion, and the distance Ra of the Hansen solubility parameter between the carbon nanotubes and the dispersion medium was calculated using the formula (I). All these results are shown in Table 3.
＜実施例６＞
　分散媒として、アセトフェノンに代えてｐ－クロロトルエンを用いた以外は、実施例５と同様にしてＣＮＴ分散液を得た。
　次に、得られたＣＮＴ分散液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度１５０℃で２時間乾燥させ、成膜基材上に炭素膜を形成した。その後、炭素膜を基成膜基材から剥離して、厚み１３μｍの炭素膜を得た。そして、実施例５と同様にして各種評価及び測定を行った。結果を表３に示す。 <Example 6>
A CNT dispersion was obtained in the same manner as in Example 5, except that p-chlorotoluene was used as the dispersion medium instead of acetophenone.
Next, the resulting CNT dispersion was applied onto a film-forming substrate. After air-drying, the coating film on the film forming substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a carbon film on the film forming substrate. After that, the carbon film was peeled off from the base film-forming substrate to obtain a carbon film having a thickness of 13 μm. Various evaluations and measurements were performed in the same manner as in Example 5. Table 3 shows the results.
＜比較例５＞
　分散媒として、アセトフェノンに代えて１，２，４－トリメチルベンゼンを用いた以外は、実施例５と同様にしてＣＮＴ分散液及び炭素膜を得た。そして、実施例５と同様にして各種評価及び測定を行った。結果を表３に示す。 <Comparative Example 5>
A CNT dispersion and a carbon film were obtained in the same manner as in Example 5, except that 1,2,4-trimethylbenzene was used as the dispersion medium instead of acetophenone. Various evaluations and measurements were performed in the same manner as in Example 5. Table 3 shows the results.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表３によれば、実施例５～６と、実施例５～６とは同一のＣＮＴを用いる一方で分散媒が異なる比較例５とを比較すると、|δｐ１－δｐ２|が２．５ＭＰａ１／２以下である実施例５～６のＣＮＴ分散液を用いて得られた炭素膜が、|δｐ１－δｐ２|が２．５ＭＰａ１／２超である比較例５のＣＮＴ分散液を用いて得られた炭素膜に比して体積抵抗率が低い。この比較により、実施例５～６における炭素膜の導電性向上効果を確認できる。 According to Table 3, when comparing Examples 5 and 6 with Comparative Example 5, which uses the same CNTs as in Examples 5 and 6 but uses a different dispersion medium, |δ p1 −δ p2 | is 2.5 MPa. The carbon films obtained using the CNT dispersions of Examples 5 and 6 , which are 1/2 or less, have |δ p1 −δ p2 | The volume resistivity is lower than that of the carbon film obtained by using By this comparison, the effect of improving the electrical conductivity of the carbon films in Examples 5 and 6 can be confirmed.
（実験Ｄ：エラストマー成形体）
＜実施例７＞
　実験Ａの実施例１と同様にしてＣＮＴ分散液を調製した。また別途、エラストマーとしてのＦＫＭ（フッ化ビニリデン系ゴム、ケマーズ社製、製品名「Ｖｉｔｏｎ　ＧＢＬ６００Ｓ」）０．０７５ｇをメチルエチルケトン０．３ｇに溶解し、エラストマー溶液を調製した。
　上記ＣＮＴ分散液６ｇと、上記エラストマー溶液０．３７５ｇとを混合しエラストマー混合液を得た。
　次に、得られたエラストマー混合液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度１５０℃で２時間乾燥させ、成膜基材上にシート状のエラストマー成形体（複合材料）を形成した。その後、エラストマー成形体を成膜基材から剥離して、エラストマー成形体を得た。得られたエラストマー成形体について、体積抵抗率を測定した。また体積抵抗率の測定値を、後述の比較例６で得られたエラストマー成形体の体積抵抗率を１００（基準値）として指数値に変換した。そしてＣＮＴ分散液について|δｐ１－δｐ２|を算出し、また式（Ｉ）を用いてカーボンナノチューブと分散媒とのハンセン溶解度パラメータの距離Ｒａを算出した。これらの結果を何れも表４に示す。 (Experiment D: Elastomer molding)
<Example 7>
A CNT dispersion was prepared in the same manner as in Example 1 of Experiment A. Separately, 0.075 g of FKM (vinylidene fluoride rubber, manufactured by Chemours, product name "Viton GBL600S") as an elastomer was dissolved in 0.3 g of methyl ethyl ketone to prepare an elastomer solution.
6 g of the CNT dispersion and 0.375 g of the elastomer solution were mixed to obtain an elastomer mixture.
Next, the resulting elastomer mixture was applied onto a film-forming substrate. After air-drying, the coating film on the film formation substrate was dried at a temperature of 150° C. for 2 hours using a hot plate to form a sheet-like elastomer molding (composite material) on the film formation substrate. After that, the elastomer molded article was peeled off from the film-forming substrate to obtain an elastomer molded article. The volume resistivity of the obtained elastomer molding was measured. The measured value of volume resistivity was converted into an index value by setting the volume resistivity of the elastomer molding obtained in Comparative Example 6 described later as 100 (reference value). Then, |δ p1 −δ p2 | was calculated for the CNT dispersion, and the distance Ra of the Hansen solubility parameter between the carbon nanotubes and the dispersion medium was calculated using the formula (I). All these results are shown in Table 4.
＜比較例６＞
　実験Ａの比較例１と同様にしてＣＮＴ分散液を調製した。また別途、エラストマーとしてのＦＫＭ（フッ化ビニリデン系ゴム、ケマーズ社製「Ｖｉｔｏｎ　ＧＢＬ６００Ｓ」）０．０７５ｇをメチルエチルケトン０．３ｇに溶解し、エラストマー溶液を調製した。
　上記ＣＮＴ分散液６ｇと、上記エラストマー溶液０．３７５ｇとを混合しエラストマー混合液を得た。
　次に、得られたエラストマー混合液を成膜基材上に塗布した。風乾後、ホットプレートを用いて、成膜基材上の塗膜を温度６０℃で２時間乾燥させ、成膜基材上にシート状のエラストマー成形体（複合材料）を形成した。そして、実施例７と同様にして各種評価及び測定を行った。結果を表４に示す。 <Comparative Example 6>
A CNT dispersion was prepared in the same manner as in Comparative Example 1 of Experiment A. Separately, 0.075 g of FKM (vinylidene fluoride rubber, “Viton GBL600S” manufactured by Chemours) as an elastomer was dissolved in 0.3 g of methyl ethyl ketone to prepare an elastomer solution.
6 g of the CNT dispersion and 0.375 g of the elastomer solution were mixed to obtain an elastomer mixture.
Next, the resulting elastomer mixture was applied onto a film-forming substrate. After air-drying, the coating film on the film-forming substrate was dried at a temperature of 60° C. for 2 hours using a hot plate to form a sheet-like elastomer molding (composite material) on the film-forming substrate. Various evaluations and measurements were performed in the same manner as in Example 7. Table 4 shows the results.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表４によれば、実施例７と、実施例７とは同一のＣＮＴを用いる一方で分散媒が異なる比較例６とを比較すると、|δｐ１－δｐ２|が２．５ＭＰａ１／２以下であるＣＮＴ分散液を用いて得られた実施例７のエラストマー成形体が、|δｐ１－δｐ２|が２．５ＭＰａ１／２超であるＣＮＴ分散液を用いて得られた比較例６のエラストマー成形体に比して体積抵抗率が低い。この比較により、実施例７におけるエラストマー成形体の導電性向上効果を確認できる。 According to Table 4, when comparing Example 7 with Comparative Example 6, which uses the same CNTs as in Example 7 but uses a different dispersion medium, |δ p1 −δ p2 | is 2.5 MPa 1/2 or less. The elastomer molded article of Example 7 obtained using the CNT dispersion is Volume resistivity is lower than that of elastomer moldings. By this comparison, the effect of improving the electrical conductivity of the elastomer molded article in Example 7 can be confirmed.
　本発明によれば、導電性に優れる成形体を形成しうるカーボンナノチューブ分散液を提供することができる。
　また、本発明によれば、導電性に優れる炭素膜の製造方法を提供することができる。
　そして、本発明によれば、導電性に優れるエラストマー成形体の作製に使用し得る、エラストマー混合液、複合材料の製造方法、及びエラストマー成形体の製造方法を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the carbon nanotube dispersion liquid which can form the molded object excellent in electroconductivity can be provided.
Moreover, according to the present invention, it is possible to provide a method for producing a carbon film having excellent conductivity.
Further, according to the present invention, it is possible to provide an elastomer mixed liquid, a method for producing a composite material, and a method for producing an elastomer molded article, which can be used to produce an elastomer molded article having excellent conductivity.

Claims (9)

  1. 　カーボンナノチューブと分散媒とを含むカーボンナノチューブ分散液であって、
    　前記カーボンナノチューブのハンセン溶解度パラメータＨＳＰｃの極性項δｐ１と、前記分散媒のハンセン溶解度パラメータＨＳＰｄの極性項δｐ２との差の絶対値が２．５ＭＰａ１／２以下である、カーボンナノチューブ分散液。     A carbon nanotube dispersion containing carbon nanotubes and a dispersion medium,
    Carbon nanotube dispersion, wherein the absolute value of the difference between the polar term δ p1 of the Hansen solubility parameter HSP c of the carbon nanotube and the polar term δ p2 of the Hansen solubility parameter HSP d of the dispersion medium is 2.5 MPa 1/2 or less. liquid.
  2. 　前記カーボンナノチューブの濃度が０．０１質量％以上５質量％以下である、請求項１に記載のカーボンナノチューブ分散液。 The carbon nanotube dispersion liquid according to claim 1, wherein the concentration of the carbon nanotubes is 0.01% by mass or more and 5% by mass or less.
  3. 　前記カーボンナノチューブと前記分散媒とのハンセン溶解度パラメータの距離Ｒａが４．０ＭＰａ１／２以下である、請求項１に記載のカーボンナノチューブ分散液。 2. The carbon nanotube dispersion according to claim 1, wherein the distance Ra of the Hansen solubility parameter between the carbon nanotube and the dispersion medium is 4.0 MPa< 1/2 > or less.
  4. 　前記分散媒のハンセン溶解度パラメータＨＳＰｄの分散項δｄ２が１７．５ＭＰａ１／２超である、請求項１に記載のカーボンナノチューブ分散液。 The carbon nanotube dispersion according to claim 1, wherein the dispersion term δd2 of the Hansen Solubility Parameter HSP d of the dispersion medium is greater than 17.5 MPa 1/2 .
  5. 　前記分散媒のハンセン溶解度パラメータＨＳＰｄの水素結合項δｈ２が９．０ＭＰａ１／２未満である、請求項１に記載のカーボンナノチューブ分散液。 The carbon nanotube dispersion of claim 1, wherein the hydrogen bonding term δh2 of the Hansen Solubility Parameter HSP d of the dispersion medium is less than 9.0 MPa 1/2 .
  6. 　請求項１～５の何れかに記載のカーボンナノチューブ分散液から前記分散媒を除去して成膜する工程を含む、炭素膜の製造方法。 A method for producing a carbon film, comprising a step of forming a film by removing the dispersion medium from the carbon nanotube dispersion according to any one of claims 1 to 5.
  7. 　請求項１～５の何れかに記載のカーボンナノチューブ分散液と、エラストマーとを含む、エラストマー混合液。 An elastomer mixture containing the carbon nanotube dispersion according to any one of claims 1 to 5 and an elastomer.
  8. 　請求項７に記載のエラストマー混合液から前記分散媒を除去する工程を含む、複合材料の製造方法。 A method for producing a composite material, comprising the step of removing the dispersion medium from the elastomer mixed liquid according to claim 7.
  9. 　請求項７に記載のエラストマー混合液から前記分散媒を除去して複合材料を得る工程と、
    　前記複合材料に架橋剤を添加する工程と、
    　前記架橋剤が添加された前記複合材料を架橋してエラストマー成形体を得る工程を含む、エラストマー成形体の製造方法。     A step of removing the dispersion medium from the elastomer mixture according to claim 7 to obtain a composite material;
    adding a cross-linking agent to the composite;
    A method for producing an elastomer molded article, comprising the step of cross-linking the composite material to which the cross-linking agent is added to obtain an elastomer molded article.
PCT/JP2022/042766 2021-11-22 2022-11-17 Carbon nanotube dispersion, method for producing carbon film, elastomer mixture, method for producing composite material, and method for producing elastomer molded body WO2023090403A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2021189585 2021-11-22
JP2021-189585 2021-11-22

Publications (1)

Publication Number Publication Date
WO2023090403A1 true WO2023090403A1 (en) 2023-05-25

Family

ID=86397183

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/042766 WO2023090403A1 (en) 2021-11-22 2022-11-17 Carbon nanotube dispersion, method for producing carbon film, elastomer mixture, method for producing composite material, and method for producing elastomer molded body

Country Status (1)

Country Link
WO (1) WO2023090403A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018012372A1 (en) * 2016-07-11 2018-01-18 富士フイルム株式会社 p-TYPE SEMICONDUCTOR LAYER, THERMOELECTRIC CONVERSION LAYER, THERMOELECTRIC CONVERSION ELEMENT, THERMOELECTRIC CONVERSION MODULE, AND COMPOSITION FOR FORMING p-TYPE SEMICONDUCTOR LAYER
WO2018179760A1 (en) * 2017-03-31 2018-10-04 国立研究開発法人産業技術総合研究所 Carbon nanotube dispersion
WO2021095600A1 (en) * 2019-11-14 2021-05-20 国立大学法人 奈良先端科学技術大学院大学 Carbon nanotube dispersion and method for producing same
JP2021147474A (en) * 2020-03-18 2021-09-27 日本ゼオン株式会社 Method for producing rubber composition
WO2021200126A1 (en) * 2020-03-30 2021-10-07 日本ゼオン株式会社 Conductive material dispersion liquid, slurry for secondary battery positive electrodes, positive electrode for secodnary batteries, and secondary battery
JP2021172528A (en) * 2020-04-17 2021-11-01 国立研究開発法人産業技術総合研究所 Carbon nanotube membrane, dispersion liquid, and production method of carbon nanotube membrane

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018012372A1 (en) * 2016-07-11 2018-01-18 富士フイルム株式会社 p-TYPE SEMICONDUCTOR LAYER, THERMOELECTRIC CONVERSION LAYER, THERMOELECTRIC CONVERSION ELEMENT, THERMOELECTRIC CONVERSION MODULE, AND COMPOSITION FOR FORMING p-TYPE SEMICONDUCTOR LAYER
WO2018179760A1 (en) * 2017-03-31 2018-10-04 国立研究開発法人産業技術総合研究所 Carbon nanotube dispersion
WO2021095600A1 (en) * 2019-11-14 2021-05-20 国立大学法人 奈良先端科学技術大学院大学 Carbon nanotube dispersion and method for producing same
JP2021147474A (en) * 2020-03-18 2021-09-27 日本ゼオン株式会社 Method for producing rubber composition
WO2021200126A1 (en) * 2020-03-30 2021-10-07 日本ゼオン株式会社 Conductive material dispersion liquid, slurry for secondary battery positive electrodes, positive electrode for secodnary batteries, and secondary battery
JP2021172528A (en) * 2020-04-17 2021-11-01 国立研究開発法人産業技術総合研究所 Carbon nanotube membrane, dispersion liquid, and production method of carbon nanotube membrane

Similar Documents

Publication Publication Date Title
WO2016136275A1 (en) Silicone rubber composition and vulcanized object
US11584831B2 (en) Method of producing slurry, method of producing composite resin material, and method of producing shaped product
US11643328B2 (en) Method of producing surface-treated carbon nanostructures
WO2017022229A1 (en) Composite resin material, slurry, molded composite resin material, and process for producing slurry
JP2018203914A (en) Manufacturing method of composite material
US20200024409A1 (en) Method of producing composite resin material and method of producing shaped product
JP2008273806A (en) Coating film containing dispersed micro carbon fibers and production method thereof
WO2018066528A1 (en) Slurry, and method for producing composite resin material and molded article
KR101550442B1 (en) a solid composition with an excellent re-dispersion characteristic, and a method for preparing a solid composition with an excellent re-dispersion characteristic
JP2018070709A (en) Method for producing composite resin material and method for producing molding
JP2019199583A (en) Method for producing composite material
JP2015105213A (en) Carbon nanotube and dispersion liquid thereof, and self-supporting film and composite material
KR101534298B1 (en) a composition for electro-magnetic interference shielding film, a method of fabricating a electro-magnetic interference shielding film therewith and an electro-magnetic interference shielding film fabricated thereby
WO2023090403A1 (en) Carbon nanotube dispersion, method for producing carbon film, elastomer mixture, method for producing composite material, and method for producing elastomer molded body
WO2021172555A1 (en) Elastomer composition, method for producing same, crosslinked substance, and molded body
JP7155567B2 (en) molding
JP2017031323A (en) Method for producing slurry and method for producing composite resin material
JP2008200608A (en) Production method of conductive fluororesin thin film and conductive fluororesin thin film
CN116057122B (en) Elastomer composition, method for producing elastomer composition, crosslinked product, and molded body
JP2017031005A (en) Graphene coated aluminum nitride filler and method for producing the same, electronic material, resin composite, and hydrophobic treatment method
JP2015105205A (en) Surface-treated carbon nanotube and dispersion liquid thereof, and self-supporting film and composite material
JP2010189218A (en) Carbon fiber-containing coating film and method for producing the same
JP6164067B2 (en) Carbon nanotubes and dispersions thereof, and free-standing films and composite materials
EP3978900A1 (en) Composite material evaluation method and production method, and composite material
WO2022210974A1 (en) Elastomer composition, method for producing same, crosslinked product, and molded body

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22895684

Country of ref document: EP

Kind code of ref document: A1