WO2016080327A1 - Carbon nanotube dispersion, functional film, and composite material - Google Patents

Carbon nanotube dispersion, functional film, and composite material Download PDF

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WO2016080327A1
WO2016080327A1 PCT/JP2015/082064 JP2015082064W WO2016080327A1 WO 2016080327 A1 WO2016080327 A1 WO 2016080327A1 JP 2015082064 W JP2015082064 W JP 2015082064W WO 2016080327 A1 WO2016080327 A1 WO 2016080327A1
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cnt
cnts
dispersion
functional film
dispersion liquid
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PCT/JP2015/082064
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French (fr)
Japanese (ja)
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智大 古園
拓治 小向
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ニッタ株式会社
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • 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
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30

Definitions

  • the present invention relates to a dispersion containing carbon nanotubes (hereinafter referred to as CNT), a functional film, and a composite material.
  • CNT carbon nanotubes
  • a CNT dispersion containing CNT is known as a coating solution (see Patent Document 1).
  • CNT dispersions are conventionally used for the production of conductive films imparted with electrical conductivity derived from CNTs, and conductive films imparted with electrical conductivity can be referred to as functional films.
  • conductive films imparted with electrical conductivity can be referred to as functional films.
  • the dispersibility of the CNTs in the dispersion can be enhanced by the functional groups formed on the CNT surface or the dispersant added separately.
  • a solution containing a resin as a coating film formation is used as a dispersion medium in which CNTs are dispersed.
  • CNTs are present in the resin layer. If the content of CNT in the CNT dispersion increases, the CNT-derived characteristics in the resulting functional film are enhanced, but the inherent characteristics of the resin tend to be reduced. It is desirable that the CNT content in the CNT dispersion is as small as possible within a range in which a desired function is exhibited.
  • the CNT 104 in the CNT dispersion 100 is well dispersed in the dispersion medium 102, but the functional group is lost and the characteristics of the CNT are lost. It is not possible to obtain a functional film that sufficiently exhibits the above.
  • CNTs with few functional groups on the surface have poor dispersibility in the dispersion medium 102, and a bundle of aggregates 106 and aggregates 108 are generated.
  • the dispersant is used, as shown in FIG. 13, the CNTs 114 in the CNT dispersion liquid 110 are covered with the dispersant 116 and are well dispersed in the dispersion medium 112. However, since the contact resistance is increased by the dispersant 116, the characteristics of the CNT 114 are not sufficiently exhibited in the obtained functional film.
  • CNTs with a large aspect ratio generally have low dispersibility in the dispersion medium.
  • a plurality of CNTs 124 gather to form many bundled aggregates 126 and aggregates.
  • a network between the CNTs 124 cannot be obtained sufficiently. If the CNT aspect ratio is small, the problem of aggregation does not occur. However, even in a CNT dispersion containing CNT having a small aspect ratio and a dispersion medium, a network of CNTs cannot be sufficiently obtained.
  • the content in the CNT dispersion liquid is set for both CNTs having a large aspect ratio and CNTs having a small aspect ratio. Need to increase.
  • the CNT aggregates 108 exist in the resin layer 202 as shown in FIG.
  • the shape of the aggregate 108 becomes a convex portion 204 and appears on the surface of the functional film 200.
  • the flatness of the film surface is impaired and the film thickness varies.
  • the strength of the functional film 200 is reduced.
  • the CNT dispersion liquid which can produce the functional film which fully provided the characteristic derived from CNT, without impairing the original characteristic of a coating-film formation has not been obtained yet.
  • the present invention provides a CNT dispersion that can provide a functional film that sufficiently exhibits the characteristics derived from CNTs while sufficiently maintaining the original characteristics of the coating film formed product, a functional film using the same, and a composite material
  • the purpose is to provide.
  • the CNT dispersion according to the present invention is a CNT dispersion containing a dispersion medium containing a coating film formation product and a solvent, and CNTs dispersed in the dispersion medium, and the concentration x (volume%) of the CNT,
  • the thixo index y ( ⁇ 100 / ⁇ 400) satisfies the relationship of the following formulas (1), (2), (3), and (4).
  • ⁇ 100 is the viscosity (mPa ⁇ s) at a shear rate of 100 (1 / sec)
  • ⁇ 400 is the viscosity (mPa ⁇ s) at a shear rate of 400 (1 / sec).
  • the functional film according to the present invention is formed using the CNT dispersion liquid.
  • a composite material according to the present invention includes a base material and the functional film that covers the surface of the base material.
  • the CNT dispersion has a higher TI value y than the conventional one, a functional film in which the characteristics derived from CNT are sufficiently exhibited while sufficiently maintaining the original characteristics of the coating film formation, And a composite material provided with a functional film can be formed.
  • FIG. 2A is a schematic diagram illustrating the configuration of the functional film of the present embodiment
  • FIG. 2B is an enlarged view of a portion surrounded by a square frame in FIG. 2A.
  • FIG. 4A is an SEM (scanning electron microscope) photograph of the CNT used in the example
  • FIG. 4B is an enlarged photograph of FIG. 4A.
  • FIG. 5A is an SEM photograph of CNT used in the comparative example
  • FIG. 5B is an enlarged photograph of FIG. 5A.
  • 6A is an SEM photograph of CNT used in the comparative example
  • FIG. 6B is an enlarged photograph of FIG. 6A.
  • FIG. 7A is an SEM photograph of CNT used in the comparative example, and FIG. 7B is an enlarged photograph of FIG. 7A.
  • FIG. 8A is an SEM photograph of CNT used in the comparative example, and FIG. 8B is an enlarged photograph of FIG. 8A.
  • concentration (volume%) concentration (volume%)
  • the composite material 10 includes a base material 12 and a functional film 20 provided on the surface of the base material 12.
  • the base material 12 is not particularly limited, and can be any shape that requires electrical conductivity, thermal conductivity, or mechanical strength.
  • the material of the base material 12 can be selected from, for example, a polymer material such as a PET film, a metal material such as a stainless steel foil, and an inorganic material such as a glass plate and ceramics.
  • the functional film 20 has a film thickness t as shown in FIG. 2A.
  • the CNTs 34 are uniformly dispersed in the coating film 22 and entangled with each other to form a network structure 24. Yes.
  • a thin film thickness of about 0.1 to 100 ⁇ m, preferably 30 ⁇ m or less, and even if the contained CNT 34 is at a low concentration, it is derived from CNT such as electrical conductivity, thermal conductivity, or mechanical strength.
  • the functional film 20 of the present embodiment can suppress the strength reduction caused by the CNTs 34, and can maintain the original characteristics of the coating film 22 if the CNTs 34 have a low concentration.
  • the surface of the base material 12 on which the functional film 20 is provided is not limited to a flat surface, and may be a curved surface. Since the functional film 20 can be formed with a small film thickness, even if the surface of the base material 12 is a curved surface, the surface of the base material 12 can be covered well following the curved surface.
  • the base material 12 is a container having a predetermined shape, the functional film 20 may be formed on the inner surface of the container. Since the functional film 20 can be formed with a thin film thickness, even if it is formed on the inner surface of the container, the effect on the volume of the container is small.
  • the composite material 10 of this embodiment can be manufactured using the CNT dispersion 30 shown in FIG.
  • the CNT dispersion liquid 30 includes a dispersion medium 32 and CNTs 34 dispersed in the dispersion medium 32.
  • the dispersion medium 32 is a solution in which a resin as a coating film formation is dissolved in a solvent, and the resin and the solvent are used in a predetermined combination.
  • a resin as a coating film formation
  • NMP N-methyl-2-pyrrolidone
  • the concentration of PI in the entire dispersion medium 32 is preferably about 0.5 to 15% by volume, and more preferably about 2 to 10% by volume.
  • PVP polyvinyl pyrrolidone
  • water is used as the solvent, for example.
  • the concentration of PVP in the entire dispersion medium 32 is preferably about 9 to 70% by volume, more preferably about 20 to 60% by volume.
  • Polyamideimide can also be used as the resin, and NMP and dimethylacetamide are used as the PAI solvent, for example.
  • concentration of PAI in the entire dispersion medium 32 is preferably about 0.5 to 24% by volume, and more preferably about 3 to 15% by volume.
  • epoxy or urethane may be used as the resin.
  • MEK methyl ethyl ketone
  • acetone can be used as the solvent, respectively.
  • the resin in the dispersion medium 32 contained in the CNT dispersion 30 constitutes the coating film 22 in the functional film 20.
  • the CNT 34 is preferably about 1 to 100 ⁇ m in length and has a high aspect ratio.
  • the CNT dispersion liquid 30 of the present embodiment is prepared using a longer CNT 34 as a raw material.
  • the CNT 34 contained in the CNT dispersion 30 in FIG. 3 is obtained by shortening a longer material CNT by a dispersion process.
  • the length of the CNTs 34 in the CNT dispersion 30 is 1 ⁇ m or more, the CNTs 34 are entangled with each other in the functional film 20 and directly connected to each other, thereby forming a good network structure 24 (see FIG. 2B). Further, the CNTs 34 tend to aggregate when the length exceeds 100 ⁇ m.
  • the length of the CNT 34 is less than 1 ⁇ m, it is difficult to form the network structure 24 in the functional film 20.
  • the CNT 34 preferably has a diameter of about 30 nm or less. If the diameter of the CNT 34 is 30 nm or less, the CNT 34 is rich in flexibility and easily deforms, and therefore can exist in the CNT dispersion 30 without restriction. On the other hand, if the diameter of the CNT 34 exceeds 30 nm, the flexibility is lost and it becomes difficult to form the network structure 24. More preferably, the CNT 34 has a diameter of 20 nm or less.
  • the length and diameter of the CNT 34 are the average values measured using a transmission electron microscope (TEM) photo.
  • the surface of the CNT 34 has few defects.
  • Defects on the surface of CNT 34 are carboxyl group (—COOH), sulfone group (—SO 3 H), nitro group (—NO 2 ), aldehyde group (—CHO), amino group (—NH 2 ), and hydroxyl group (—OH).
  • the functional group is imparted by a surface treatment.
  • many functional groups existed on the surface for the purpose of improving the dispersibility in the CNT dispersion. Since the CNTs 34 contained in the CNT dispersion 30 of the present embodiment are not subjected to surface treatment, there are few defects due to functional groups.
  • a viscosity ⁇ 100 (mPa ⁇ s) at a shear rate of 100 (1 / sec) and a viscosity ⁇ 400 (at a shear rate of 400 (1 / sec)) ( mPa ⁇ s)) and a thixo index (TI value) represented by a ratio ( ⁇ 100 / ⁇ 400) and a CNT concentration (volume%) in the CNT dispersion 30 were found.
  • the following expressions (1), (2), (3), and (4) are present between the CNT concentration x (volume%) and the TI value y.
  • nano-dispersion means a state where CNTs 34 are physically separated and dispersed in a state where they are not entangled one by one. It means a state in which the proportion of objects is 10% or less.
  • the CNT dispersion liquid 30 of this embodiment can be prepared by dispersing predetermined CNTs 34 in the dispersion medium 32.
  • the raw material CNT used for the preparation of the CNT dispersion 30 is obtained by forming a catalyst film made of aluminum or iron on a silicon substrate using a thermal CVD method as described in, for example, Japanese Patent Application Laid-Open No. 2007-12611.
  • the catalyst metal for the growth of CNTs can be made fine and the hydrocarbon gas can be brought into contact with the catalyst metal in a heated atmosphere.
  • CNTs obtained by other manufacturing methods such as arc discharge method and laser evaporation method
  • impurities other than CNTs may be removed by high-temperature annealing in an inert gas after the CNTs are manufactured.
  • the CNTs 34 manufactured in this manufacturing example are long and linearly oriented with a high aspect ratio of a diameter of 30 nm or less and a length of several hundred ⁇ m to several mm.
  • the CNT 34 may be a single layer or a multilayer, but a multilayer is preferable.
  • the dispersion medium 32 can be prepared by dissolving the resin in a predetermined solvent at a predetermined concentration.
  • the CNT dispersion 30 is obtained by pulverizing the CNTs 34 produced as described above and adding them to the dispersion medium 32, and then nano-dispersing the CNTs 34 in the dispersion medium 32 using a wet disperser, a homogenizer, an ultrasonic disperser, or the like. Can be prepared.
  • the CNT 34 may be pretreated as long as a desired length is obtained and the functional groups on the surface are not lost.
  • wet dispersion in a viscous liquid.
  • wet dispersion it is possible to prevent entanglement between the CNTs and cutting or damage of the CNTs due to rubbing.
  • additives such as a dispersant, a surfactant, a thixotropic agent (viscoelasticity modifier) and the like are not necessarily required, but do not adversely affect the effects of the present invention. If so, such additives may be used.
  • the CNT dispersion 30 of the present embodiment as described above is applied on a predetermined base material 12 by bar coating, spraying, spin coating, knife coating, dip coating, or the like.
  • the CNTs 34 in the CNT dispersion 30 are nano-dispersed by receiving shear stress.
  • the amount of the CNT dispersion 30 to be applied can be adjusted so that the functional film 20 having a target film thickness can be obtained.
  • the functional film 20 can be formed by drying the applied CNT dispersion 30.
  • the CNT 34 is fixed in a state where the network structure 24 is formed. What is necessary is just to set drying conditions suitably according to the kind of resin and solvent which are contained in the dispersion medium 32 in the CNT dispersion liquid 30.
  • drying conditions suitably according to the kind of resin and solvent which are contained in the dispersion medium 32 in the CNT dispersion liquid 30.
  • the viscosity ⁇ 100 (mPa ⁇ s) at a shear rate of 100 (1 / sec) and the viscosity ⁇ 400 (mPa ⁇ s) at a shear rate of 400 (1 / sec)) A predetermined correlation is established between the ratio ( ⁇ 100 / ⁇ 400) and the CNT concentration (volume%).
  • the CNT dispersion 30 according to the present embodiment has a TI value y exceeding a predetermined value at a predetermined CNT concentration.
  • the functional film 20 that sufficiently exhibits the characteristics derived from the CNTs 34 while sufficiently maintaining the original characteristics of the resin. Can be formed.
  • the CNTs 34 are nano-dispersed when subjected to shear stress. Therefore, the CNT 34 is nano-dispersed by receiving shear stress when the CNT dispersion 30 is applied, and can be uniformly applied to the surface of the base material 12 even at a low concentration.
  • the shear stress is lowered, so that the CNTs 34 are gradually entangled with each other to form the network structure 24.
  • the viscosity of the CNT dispersion liquid 30 is increased, it is possible to prevent dripping or the like.
  • the functional film 20 includes the network structure 24 in which the CNTs 34 are entangled with each other, excellent electrical conductivity and mechanical strength derived from CNTs can be obtained even with a film thickness of about 0.1 to 100 ⁇ m.
  • the CNT dispersion 30 can form the composite material 10 having the characteristics derived from the CNTs 34, that is, electrical conductivity and mechanical strength, by providing the functional film 20 on the surface of an arbitrary base material 12.
  • the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the gist of the present invention.
  • the functional film 20 of the present embodiment can also be formed on a predetermined support so as to be peelable.
  • the functional film 20 is formed on the support by the same method as in the case of the composite material 10 and is peeled from the support, the functional film 20 can be obtained as an independent single body.
  • the coating film formation is a resin
  • the present invention is not limited to this and can be applied to a general viscous body.
  • CNT dispersions of Examples 1 to 7 were prepared by dispersing CNTs at a predetermined concentration in a dispersion medium containing a resin and a solvent.
  • the CNTs used here are MW-CNTs (multi-walled carbon nanotubes) grown on a silicon substrate by a thermal CVD method, and have a length of 350 ⁇ m and a diameter of 13 nm.
  • FIG. 4 the SEM photograph before the dispersion
  • CNT was mixed with a dispersion medium without performing surface treatment, and dispersed in the dispersion medium using a wet disperser. Neither a dispersant nor a thixotropic agent (viscoelasticity modifier) was blended, and wet dispersion treatment was performed 15 times to obtain a CNT dispersion of the example.
  • CNT dispersions of Comparative Examples 1 to 8 were prepared using commercially available CNTs at a predetermined concentration.
  • Nanocyl CNT product number NC7000, length 1.5 ⁇ m, diameter 9.5 nm
  • SWeNT CNT product number SMW200, length 3.5 ⁇ m
  • CNTs manufactured by Cano product number FloTube 9011, length 10 ⁇ m, diameter 11 nm
  • CNTs manufactured by JEIO product number JC-400, length 1 ⁇ m, diameter 20 nm
  • the numerical values of the length and the diameter of the CNT according to the comparative example are both catalog values.
  • the length and diameter of CNT in the obtained CNT dispersion were determined by TEM observation. Note that the CNTs in the CNT dispersions of Examples 1 to 7 are presumed to have few surface functional groups and few surface defects because they are not surface-treated.
  • Viscosity at 23 ° C. was measured for the CNT dispersions of Examples and Comparative Examples. Viscosity was measured using a Wellsbrookfield cone / plate viscometer, and the shear rate was varied to determine the viscosity at 100 / sec ( ⁇ 100) and the viscosity at 400 / sec ( ⁇ 400). It was. Let ( ⁇ 100 / ⁇ 400) be the thixo index (TI value).
  • Table 1 summarizes the CNTs and dispersion media contained in the CNT dispersions of Examples and Comparative Examples, together with the viscosity and TI value of the CNT dispersions.
  • NMP is an abbreviation for N-methyl-2pyrrolidone
  • PVP and PI are abbreviations for polyvinylpyrrolidone and polyimide, respectively.
  • (volume%) of resin is the density
  • the CNTs contained in the CNT dispersions of Examples 1 to 7 are as long as about 1 to 100 ⁇ m.
  • the CNT having a length of about 20 ⁇ m has a large aspect ratio exceeding 1000.
  • the CNT dispersions of Comparative Examples 1 to 8 contain CNTs having a length of about 0.1 to 1 ⁇ m and a small aspect ratio of about 100 at the maximum.
  • 5 to 8 show SEM photographs before dispersion treatment for the CNT used in Comparative Examples 1 to 3, the CNT used in Comparative Examples 4 to 6, the CNT used in Comparative Example 7, and the CNT used in Comparative Example 8. Each is shown.
  • island-shaped aggregates 140 to 143 formed by entanglement of individual CNTs are confirmed.
  • the CNT dispersion liquid of the examples is prepared using CNT having a high aspect ratio. Although the CNTs are shortened by carrying out the dispersion treatment, the CNT dispersion liquid of the example still has a length as long as about 20 ⁇ m and contains CNTs having a very large aspect ratio exceeding 1000.
  • the CNT dispersion of the comparative example was prepared using CNT containing aggregates that were entangled and aggregated.
  • FIG. 9 is a graph showing the relationship between the CNT concentration (volume%) and the TI value described in Table 1 above as the x-axis and y-axis, respectively.
  • the CNT dispersion liquid of the example has a larger TI value y than the CNT dispersion liquid of the comparative example.
  • the CNT dispersion liquid of the example contains CNT having a length of about 20 ⁇ m and a high aspect ratio. Since the CNT dispersion liquid of the example is long and has a large aspect ratio, when the shear stress is small, the CNT dispersion liquid entangles each other and easily forms the network structure 24, so that the viscosity can be increased. In addition, the CNT dispersion liquid of the example is subjected to shear stress, so that the network structure is easily disassembled and the CNTs are nano-dispersed, so that the viscosity decreases. Thus, since the viscosity of the CNT dispersion liquid of the example changes depending on the shear stress received, a large TI value y can be obtained.
  • the CNT dispersion liquid of the example a correlation as shown in FIG. 9 was obtained between the CNT concentration (volume%) and the TI value y. Since the CNTs are shortened by carrying out the dispersion treatment, the aspect ratio of the CNTs can be reduced when preparing the CNT dispersions of the examples. When the aspect ratio of the CNT is reduced, the viscosity when the shear stress is small can be reduced, so that the TI value y of the CNT dispersion is also reduced. In other words, the above formulas (12) and (13) correspond to the upper limit of the TI value y of the CNT dispersion liquid of the example. Moreover, the CNT dispersion liquid of an Example can obtain smaller TI value y by adjusting the length and aspect ratio of CNT.
  • the CNT dispersion liquid of the example satisfies the relationships of the above formulas (1), (2), (3), and (4).
  • the CNT dispersion of the comparative example had a low TI value y of about 1.1 to 1.39 (y ⁇ 5x + 1) as shown in FIG.
  • the CNTs used in the comparative example are entangled to form aggregates 140 to 143.
  • the CNT dispersion liquid of the comparative example has many aggregates, and originally, there are few CNTs effective for taking a network structure. Even if shear stress is applied, the aggregated CNTs are shortened to become CNTs having a small aspect ratio. Even if such CNTs are dispersed, it is difficult to adopt a network structure. Therefore, it is considered that the CNT dispersion liquid of the comparative example has a small change in viscosity due to the shear stress received and a low TI value y.
  • the TI value y of the CNT dispersion also depends on the affinity between the CNT surface and the solvent in the dispersion medium. For example, when the hydrophilicity of the CNT surface is high, the TI value y is high when water is contained as the solvent, and when the lipophilicity of the CNT surface is high, an organic solvent is contained as the solvent. At this time, the TI value y increases.
  • Examples 1 and 2 using PVP as the resin water is used as the solvent.
  • Examples 3 to 7 using PI as the resin an organic solvent is used.
  • a high TI value y can be obtained regardless of whether water or an organic solvent is used.
  • the TI value y is compatible with the solvent on the CNT surface. It has nothing to do with it.
  • a high TI value y is obtained by including CNT that can easily disassemble the network structure.
  • the CNT dispersion using two types of dispersion media that is, a dispersion medium containing PVP as a resin and a dispersion medium containing PI has been described.
  • the CNT dispersion liquid of the present embodiment is not limited to these. It is not something. If CNTs with a length of 1 to 100 ⁇ m are contained, the correlation between the CNT concentration (% by volume) and the TI value y is similar to that in the case of a CNT dispersion using a dispersion medium containing other resins. Become.
  • ⁇ Surface resistivity of functional film> The CNT dispersion liquid of Example 3 was applied onto the base material with a K hand coater to form a coating film. A glass substrate was used as the base material here. Using a hot plate, the film was dried at 90 ° C. for 30 minutes and then baked at 250 ° C. for 30 minutes to form a functional film having a predetermined film thickness. The surface resistivity of the obtained functional film was measured with a four-probe resistivity meter, and the result was plotted in the graph of FIG.
  • the functional film formed using the dispersion liquid of Example 3 has a surface resistivity of about (1.0E + 3.5) ⁇ / sq with a thickness of about 10 ⁇ m.
  • the functional film formed here is a conductive film in which electrical conductivity derived from CNT is imparted to the coating film (polyimide layer).
  • the CNT dispersion of the comparative example does not disassemble CNT aggregates even when subjected to shear stress. Therefore, when compared at the same CNT concentration, the TI value y is smaller than that of the CNT dispersion of the example.
  • the functional film formed with the CNT dispersion liquid of the comparative example since the CNT cannot form a network structure, a functional film that sufficiently exhibits the characteristics (electric conductivity) of the CNT is formed with a thin film thickness. I can't.
  • FIG. 11 is an SEM photograph of the surface of the functional film formed on the base material by the method described above. According to the SEM photograph of FIG. 11, it can be seen that a large amount of CNT having a length of 2.5 ⁇ m or more is present, and there are few aggregates and aggregates in which the CNTs are gathered in a bundle.
  • the CNT length here is the length of a part of the CNT existing in the vicinity of the film surface, not the entire length, so it is estimated that it is actually longer. It is presumed that the electrical conductivity of the functional film has been improved due to the fact that the CNTs are long and there are few defects on the CNT surface.
  • ⁇ Scratch strength of film> The CNT dispersion liquid of Example 3 was applied onto the base material by spray coating. Stainless steel was used as the base material here. It dried at 200 degreeC for 30 minutes using the dryer, and imidation was performed at 300 degreeC for 30 minutes. A functional film having a thickness of 17 to 18 ⁇ m was formed. For comparison, a thin film (polyimide film) having the same thickness was formed using only the dispersion medium without blending CNTs.
  • the strength was measured with a scratching needle with an arbitrary load applied to the obtained functional film and thin film. The strength when each film peels from the base material is compared.
  • the testing machine used was a Haydon friction measuring machine, the scratching needle was made of sapphire (0.05 mm, R60 °), and the scratching speed was 20 mm / min.
  • Example 3 Although the functional film using the CNT dispersion liquid of Example 3 was scraped at 0.98 N, it was confirmed that the scratch strength was improved without tearing to 2.45 N. On the other hand, the comparative polyimide film was scraped at 0.98N and was torn at 1.47N.

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Abstract

A CNT dispersion (30) including: a dispersion medium (32) including a coating film-forming material and a solvent; and carbon nanotubes (34) dispersed in the dispersion medium. The CNT dispersion (30) is characterized by the carbon nanotube (34) concentration x (vol%) and the thixotropy index y (η100/η400) fulfilling relationships (1), (2), (3), and (4). y > 5x + 1 (1); y ≤ 9.5x + 1.3 (2); y ≤ 17.4x + 0.93 (3); 0.01 ≤ x ≤ 0.15 (4) (η100 refers to the viscosity (mPa·s) at a shear velocity of 100 (l/sec) and η400 refers to viscosity (mPa·s) at a shear velocity of 400 (l/sec).

Description

カーボンナノチューブ分散液、機能性膜および複合素材Carbon nanotube dispersion, functional membrane and composite material
　本発明は、カーボンナノチューブ（以下、ＣＮＴと称する）を含む分散液、機能性膜および複合素材に関する。 The present invention relates to a dispersion containing carbon nanotubes (hereinafter referred to as CNT), a functional film, and a composite material.
　ＣＮＴを含むＣＮＴ分散液は塗布液として知られている（特許文献１参照）。ＣＮＴ分散液は、従来、ＣＮＴ由来の電気伝導性を付与した導電膜の製造に用いられており、電気伝導性が付与された導電膜は、機能性膜と称することができる。特性のバラツキを抑制して強度の高い機能性膜を得るためには、ＣＮＴが分散媒中に均一に分散されていることが求められる。ＣＮＴ表面に形成された官能基、あるいは別途配合された分散剤によって、分散液中のＣＮＴの分散性を高めることができる。 A CNT dispersion containing CNT is known as a coating solution (see Patent Document 1). CNT dispersions are conventionally used for the production of conductive films imparted with electrical conductivity derived from CNTs, and conductive films imparted with electrical conductivity can be referred to as functional films. In order to obtain a functional film having high strength by suppressing variation in characteristics, it is required that CNTs are uniformly dispersed in a dispersion medium. The dispersibility of the CNTs in the dispersion can be enhanced by the functional groups formed on the CNT surface or the dispersant added separately.
　ＣＮＴが分散される分散媒としては塗膜形成物としての樹脂を含む溶液が用いられ、機能性膜においては、ＣＮＴは樹脂層中に存在することになる。ＣＮＴ分散液中のＣＮＴの含有量が多くなると、得られる機能性膜におけるＣＮＴ由来の特性は高められるものの、樹脂本来の特性が低下する傾向となる。ＣＮＴ分散液中のＣＮＴ含有量は、所望の機能が発揮される範囲で可能な限り少ないことが望まれる。 As a dispersion medium in which CNTs are dispersed, a solution containing a resin as a coating film formation is used. In the functional film, CNTs are present in the resin layer. If the content of CNT in the CNT dispersion increases, the CNT-derived characteristics in the resulting functional film are enhanced, but the inherent characteristics of the resin tend to be reduced. It is desirable that the CNT content in the CNT dispersion is as small as possible within a range in which a desired function is exhibited.
特開２０１２－１４４３８８号公報JP 2012-144388 A
　ＣＮＴの表面に官能基が多く存在していれば、図１２に示されるように、ＣＮＴ分散液１００中のＣＮＴ１０４は分散媒１０２に良好に分散するものの、官能基が欠損となってＣＮＴの特性を十分に発揮した機能性膜を得ることができない。一方、表面の官能基が少ないＣＮＴは分散媒１０２中での分散性が悪く、束状の集合体１０６や凝集体１０８が生じる。分散剤を用いた場合には、図１３に示されるように、ＣＮＴ分散液１１０中のＣＮＴ１１４は、分散剤１１６に覆われて分散媒１１２に良好に分散される。しかしながら、分散剤１１６により接触抵抗が増大するので、得られる機能性膜においてはＣＮＴ１１４の特性が十分に発揮されない。 If there are many functional groups on the surface of the CNT, as shown in FIG. 12, the CNT 104 in the CNT dispersion 100 is well dispersed in the dispersion medium 102, but the functional group is lost and the characteristics of the CNT are lost. It is not possible to obtain a functional film that sufficiently exhibits the above. On the other hand, CNTs with few functional groups on the surface have poor dispersibility in the dispersion medium 102, and a bundle of aggregates 106 and aggregates 108 are generated. When the dispersant is used, as shown in FIG. 13, the CNTs 114 in the CNT dispersion liquid 110 are covered with the dispersant 116 and are well dispersed in the dispersion medium 112. However, since the contact resistance is increased by the dispersant 116, the characteristics of the CNT 114 are not sufficiently exhibited in the obtained functional film.
　アスペクト比の大きなＣＮＴは、一般的に分散媒に対する分散性が低い。図１４に示されるように、アスペクト比の大きなＣＮＴ１２４が分散媒１２２に分散されたＣＮＴ分散液１２０においては、複数のＣＮＴ１２４が集合して束状の集合体１２６や凝集体を多く形成するが、ＣＮＴ１２４同士のネットワークを十分に得られない。ＣＮＴのアスペクト比が小さければ、凝集の問題は起こらない。しかしながら、アスペクト比の小さいＣＮＴと分散媒とを含むＣＮＴ分散液においても、ＣＮＴ同士のネットワークを十分に得られない。ＣＮＴ同士のネットワークを得ることによりＣＮＴの特性を十分に発揮した機能性膜を得るためには、アスペクト比の大きいＣＮＴおよびアスペクト比の小さいＣＮＴのいずれの場合も、ＣＮＴ分散液中の含有量を高める必要がある。 CNTs with a large aspect ratio generally have low dispersibility in the dispersion medium. As shown in FIG. 14, in the CNT dispersion liquid 120 in which the CNTs 124 having a large aspect ratio are dispersed in the dispersion medium 122, a plurality of CNTs 124 gather to form many bundled aggregates 126 and aggregates. A network between the CNTs 124 cannot be obtained sufficiently. If the CNT aspect ratio is small, the problem of aggregation does not occur. However, even in a CNT dispersion containing CNT having a small aspect ratio and a dispersion medium, a network of CNTs cannot be sufficiently obtained. In order to obtain a functional film that sufficiently exhibits the characteristics of CNTs by obtaining a network of CNTs, the content in the CNT dispersion liquid is set for both CNTs having a large aspect ratio and CNTs having a small aspect ratio. Need to increase.
　なお、ＣＮＴが凝集体を形成している分散液を用いて形成された機能性膜２００においては、図１５に示すように、樹脂層２０２中にＣＮＴの凝集体１０８が存在する。凝集体１０８の形状は凸部２０４となって機能性膜２００の表面に現れる。膜厚の小さな機能性膜２００の場合には、膜表面の平坦性が損なわれ、膜厚のバラつきが生じる。凝集体１０８が機能性膜２００の表面に現れた場合には、機能性膜２００の強度低下が引き起こされる。 Note that, in the functional film 200 formed using a dispersion in which CNTs form aggregates, the CNT aggregates 108 exist in the resin layer 202 as shown in FIG. The shape of the aggregate 108 becomes a convex portion 204 and appears on the surface of the functional film 200. In the case of the functional film 200 having a small film thickness, the flatness of the film surface is impaired and the film thickness varies. When the aggregate 108 appears on the surface of the functional film 200, the strength of the functional film 200 is reduced.
　塗膜形成物本来の特性を損なわず、ＣＮＴ由来の特性を十分に付与した機能性膜を作製できるＣＮＴ分散液は、未だ得られていない。 The CNT dispersion liquid which can produce the functional film which fully provided the characteristic derived from CNT, without impairing the original characteristic of a coating-film formation has not been obtained yet.
　そこで本発明は、塗膜形成物本来の特性を十分に維持しつつ、ＣＮＴ由来の特性が十分に発揮された機能性膜が得られるＣＮＴ分散液、これを用いた機能性膜、および複合素材を提供することを目的とする。 Accordingly, the present invention provides a CNT dispersion that can provide a functional film that sufficiently exhibits the characteristics derived from CNTs while sufficiently maintaining the original characteristics of the coating film formed product, a functional film using the same, and a composite material The purpose is to provide.
　本発明に係るＣＮＴ分散液は、塗膜形成物および溶媒を含む分散媒と、前記分散媒に分散されたＣＮＴとを含むＣＮＴ分散液であって、前記ＣＮＴの濃度ｘ（体積％）と、チキソ指数ｙ（η１００／η４００）とが、下記式（１）、式（２）、式（３）および式（４）の関係を満足することを特徴とする。
　　　ｙ＞５ｘ＋１　　　　　　　　　（１）
　　　ｙ≦９．５ｘ＋１．３　　　　　（２）
　　　ｙ≦１７．４ｘ＋０．９３　　　（３）
　　　０．０１≦ｘ≦０．１５　　　　（４）
（前記η１００はせん断速度１００（１／ｓｅｃ）における粘度（ｍＰａ・ｓ）であり、η４００はせん断速度４００（１／ｓｅｃ）における粘度（ｍＰａ・ｓ）である。） The CNT dispersion according to the present invention is a CNT dispersion containing a dispersion medium containing a coating film formation product and a solvent, and CNTs dispersed in the dispersion medium, and the concentration x (volume%) of the CNT, The thixo index y (η100 / η400) satisfies the relationship of the following formulas (1), (2), (3), and (4).
y> 5x + 1 (1)
y ≦ 9.5x + 1.3 (2)
y ≦ 17.4x + 0.93 (3)
0.01 ≦ x ≦ 0.15 (4)
(Η100 is the viscosity (mPa · s) at a shear rate of 100 (1 / sec), and η400 is the viscosity (mPa · s) at a shear rate of 400 (1 / sec).)
　本発明に係る機能性膜は、上記ＣＮＴ分散液を用いて形成されたことを特徴とする。 The functional film according to the present invention is formed using the CNT dispersion liquid.
　本発明に係る複合素材は、母材と、前記母材の表面を被覆する上記機能性膜とを備えることを特徴とする。 A composite material according to the present invention includes a base material and the functional film that covers the surface of the base material.
　本発明によれば、ＣＮＴ分散液は、従来に比べ、ＴＩ値ｙが高いので、塗膜形成物本来の特性を十分に維持しつつ、ＣＮＴ由来の特性が十分に発揮された機能性膜、および機能性膜を備えた複合素材を形成することができる。 According to the present invention, since the CNT dispersion has a higher TI value y than the conventional one, a functional film in which the characteristics derived from CNT are sufficiently exhibited while sufficiently maintaining the original characteristics of the coating film formation, And a composite material provided with a functional film can be formed.
本実施形態の複合素材の断面図である。It is sectional drawing of the composite material of this embodiment. 図２Ａは本実施形態の機能性膜の構成を示す概略図であり、図２Ｂは図２Ａの四角枠で囲む部分の拡大図である。FIG. 2A is a schematic diagram illustrating the configuration of the functional film of the present embodiment, and FIG. 2B is an enlarged view of a portion surrounded by a square frame in FIG. 2A. 本実施形態に係るＣＮＴ分散液の概念構成図である。It is a conceptual block diagram of the CNT dispersion liquid which concerns on this embodiment. 図４Ａは実施例に用いられるＣＮＴのＳＥＭ（走査型電子顕微鏡）写真であり、図４Ｂは図４Ａの拡大写真である。4A is an SEM (scanning electron microscope) photograph of the CNT used in the example, and FIG. 4B is an enlarged photograph of FIG. 4A. 図５Ａは比較例に用いられるＣＮＴのＳＥＭ写真であり、図５Ｂは図５Ａの拡大写真である。FIG. 5A is an SEM photograph of CNT used in the comparative example, and FIG. 5B is an enlarged photograph of FIG. 5A. 図６Ａは比較例に用いられるＣＮＴのＳＥＭ写真であり、図６Ｂは図６Ａの拡大写真である。6A is an SEM photograph of CNT used in the comparative example, and FIG. 6B is an enlarged photograph of FIG. 6A. 図７Ａは比較例に用いられるＣＮＴのＳＥＭ写真であり、図７Ｂは図７Ａの拡大写真である。FIG. 7A is an SEM photograph of CNT used in the comparative example, and FIG. 7B is an enlarged photograph of FIG. 7A. 図８Ａは比較例に用いられるＣＮＴのＳＥＭ写真であり、図８Ｂは図８Ａの拡大写真である。FIG. 8A is an SEM photograph of CNT used in the comparative example, and FIG. 8B is an enlarged photograph of FIG. 8A. ＣＮＴ濃度（体積％）とチキソ指数との関係を示す図である。It is a figure which shows the relationship between CNT density | concentration (volume%) and a thixo index. 実施例の機能性膜の膜厚と表面抵抗率との関係を示す図である。It is a figure which shows the relationship between the film thickness of the functional film of an Example, and surface resistivity. 実施例の機能性膜の表面のＳＥＭ写真である。It is a SEM photograph of the surface of the functional film of an example. 従来のＣＮＴ分散液の概念構成図（１）である。It is a conceptual block diagram (1) of the conventional CNT dispersion liquid. 従来のＣＮＴ分散液の概念構成図（２）である。It is a conceptual block diagram (2) of the conventional CNT dispersion liquid. 従来のＣＮＴ分散液の概念構成図（３）である。It is a conceptual block diagram (3) of the conventional CNT dispersion liquid. 従来のＣＮＴ分散液を用いて得られる機能性膜の概念構成図である。It is a conceptual block diagram of the functional film obtained using the conventional CNT dispersion liquid.
　以下、図面を参照して本発明の実施形態について詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
［構成］
　図１に示すように、複合素材１０は、母材１２と、この母材１２の表面に設けられた機能性膜２０とを備える。 [Constitution]
As shown in FIG. 1, the composite material 10 includes a base material 12 and a functional film 20 provided on the surface of the base material 12.
　母材１２は特に限定されず、電気伝導性、熱伝導性あるいは機械強度が求められる任意の形状のものを用いることができる。母材１２の材質は、例えばＰＥＴフィルムなどの高分子材料やステンレス箔などの金属材料、その他、ガラス板やセラミックスなどの無機材料等から選択することができる。 The base material 12 is not particularly limited, and can be any shape that requires electrical conductivity, thermal conductivity, or mechanical strength. The material of the base material 12 can be selected from, for example, a polymer material such as a PET film, a metal material such as a stainless steel foil, and an inorganic material such as a glass plate and ceramics.
　機能性膜２０は、図２Ａに示すように膜厚ｔを有し、図２Ｂの拡大図に示すように、塗膜２２中にＣＮＴ３４が均一分散して互いに絡み合ってネットワーク構造２４を形成している。このため、０．１～１００μｍ程度、好ましくは３０μｍ以下と薄い膜厚の場合でも、また、含有されるＣＮＴ３４が低濃度であっても、電気伝導性、熱伝導性、あるいは機械強度といったＣＮＴ由来の特性が機能性膜２０に付与される。 The functional film 20 has a film thickness t as shown in FIG. 2A. As shown in the enlarged view of FIG. 2B, the CNTs 34 are uniformly dispersed in the coating film 22 and entangled with each other to form a network structure 24. Yes. For this reason, even in the case of a thin film thickness of about 0.1 to 100 μm, preferably 30 μm or less, and even if the contained CNT 34 is at a low concentration, it is derived from CNT such as electrical conductivity, thermal conductivity, or mechanical strength. These characteristics are imparted to the functional film 20.
　機能性膜２０の膜厚が薄い場合でも、ＣＮＴ３４の凝集体が表面に現れることはなく、ＣＮＴ３４の形状が機能性膜２０の表面に反映されずに、平坦面が得られる。本実施形態の機能性膜２０は、ＣＮＴ３４に起因する強度低下は抑制され、ＣＮＴ３４が低濃度であれば塗膜２２本来の特性も維持することができる。 Even when the functional film 20 is thin, aggregates of the CNTs 34 do not appear on the surface, and the shape of the CNTs 34 is not reflected on the surface of the functional film 20 and a flat surface is obtained. The functional film 20 of the present embodiment can suppress the strength reduction caused by the CNTs 34, and can maintain the original characteristics of the coating film 22 if the CNTs 34 have a low concentration.
　図２Ａに示すように機能性膜２０は曲げることができるので、機能性膜２０が設けられる母材１２の表面は平面に限定されず、曲面であってもよい。機能性膜２０は薄い膜厚で形成できることから、母材１２表面が曲面であっても、その曲面に良好に追従して母材１２の表面を覆うことができる。また、母材１２が所定形状の容器の場合には、容器の内面に機能性膜２０を形成してもよい。機能性膜２０は薄い膜厚で形成できるので、容器内面に形成しても、容器の容積に及ぼす影響は小さい。 Since the functional film 20 can be bent as shown in FIG. 2A, the surface of the base material 12 on which the functional film 20 is provided is not limited to a flat surface, and may be a curved surface. Since the functional film 20 can be formed with a small film thickness, even if the surface of the base material 12 is a curved surface, the surface of the base material 12 can be covered well following the curved surface. When the base material 12 is a container having a predetermined shape, the functional film 20 may be formed on the inner surface of the container. Since the functional film 20 can be formed with a thin film thickness, even if it is formed on the inner surface of the container, the effect on the volume of the container is small.
［製造方法］
　本実施形態の複合素材１０は、図３に示すＣＮＴ分散液３０を用いて製造することができる。ＣＮＴ分散液３０は、分散媒３２と、この分散媒３２中に分散されたＣＮＴ３４とを備える。 [Production method]
The composite material 10 of this embodiment can be manufactured using the CNT dispersion 30 shown in FIG. The CNT dispersion liquid 30 includes a dispersion medium 32 and CNTs 34 dispersed in the dispersion medium 32.
　分散媒３２は、塗膜形成物としての樹脂が溶媒に溶解された溶液であり、樹脂と溶媒とは所定の組み合わせで用いられる。例えば、樹脂としてポリイミド（ＰＩ）が用いられる場合には、溶媒としては、例えばＮＭＰ（Ｎ－メチル－２－ピロリドン）が用いられる。分散媒３２全体におけるＰＩの濃度は、０．５～１５体積％程度が好ましく、２～１０体積％程度がより好ましい。また、樹脂としてポリビニルピロリドン（ＰＶＰ）が用いられる場合には、溶媒としては、例えば水が用いられる。この場合、分散媒３２全体におけるＰＶＰの濃度は、９～７０体積％程度が好ましく、２０～６０体積％程度がより好ましい。 The dispersion medium 32 is a solution in which a resin as a coating film formation is dissolved in a solvent, and the resin and the solvent are used in a predetermined combination. For example, when polyimide (PI) is used as the resin, NMP (N-methyl-2-pyrrolidone) is used as the solvent, for example. The concentration of PI in the entire dispersion medium 32 is preferably about 0.5 to 15% by volume, and more preferably about 2 to 10% by volume. When polyvinyl pyrrolidone (PVP) is used as the resin, water is used as the solvent, for example. In this case, the concentration of PVP in the entire dispersion medium 32 is preferably about 9 to 70% by volume, more preferably about 20 to 60% by volume.
　樹脂としてポリアミドイミド（ＰＡＩ）を用いることもでき、ＰＡＩの溶媒としては、例えばＮＭＰ、ジメチルアセトアミドが用いられる。この場合、分散媒３２全体におけるＰＡＩの濃度は、０．５～２４体積％程度が好ましく、３～１５体積％程度がより好ましい。 Polyamideimide (PAI) can also be used as the resin, and NMP and dimethylacetamide are used as the PAI solvent, for example. In this case, the concentration of PAI in the entire dispersion medium 32 is preferably about 0.5 to 24% by volume, and more preferably about 3 to 15% by volume.
　また、樹脂としてエポキシやウレタンを用いてもよい。この場合、溶媒としては、それぞれＭＥＫ（メチルエチルケトン）やアセトンを用いることができる。 Also, epoxy or urethane may be used as the resin. In this case, MEK (methyl ethyl ketone) or acetone can be used as the solvent, respectively.
　ＣＮＴ分散液３０に含有される分散媒３２中の樹脂が、機能性膜２０における塗膜２２を構成する。 The resin in the dispersion medium 32 contained in the CNT dispersion 30 constitutes the coating film 22 in the functional film 20.
　ＣＮＴ３４は、長さが１～１００μｍ程度で高いアスペクト比を有していることが好ましい。追って説明するように、本実施形態のＣＮＴ分散液３０は、より長尺のＣＮＴ３４を原料として用いて調製される。図３のＣＮＴ分散液３０中に含有されるＣＮＴ３４は、より長尺の原料ＣＮＴが分散処理によって短尺化したものである。ＣＮＴ分散液３０中のＣＮＴ３４の長さが１μｍ以上であると、機能性膜２０においてＣＮＴ３４同士が絡み合い直接接続され、良好なネットワーク構造２４を形成し得る（図２Ｂ参照）。また、ＣＮＴ３４は、長さが１００μｍ超であると凝集しやすくなる。一方、ＣＮＴ３４は、長さが１μｍ未満であると、機能性膜２０においてネットワーク構造２４を形成し難くなる。 The CNT 34 is preferably about 1 to 100 μm in length and has a high aspect ratio. As will be described later, the CNT dispersion liquid 30 of the present embodiment is prepared using a longer CNT 34 as a raw material. The CNT 34 contained in the CNT dispersion 30 in FIG. 3 is obtained by shortening a longer material CNT by a dispersion process. When the length of the CNTs 34 in the CNT dispersion 30 is 1 μm or more, the CNTs 34 are entangled with each other in the functional film 20 and directly connected to each other, thereby forming a good network structure 24 (see FIG. 2B). Further, the CNTs 34 tend to aggregate when the length exceeds 100 μm. On the other hand, when the length of the CNT 34 is less than 1 μm, it is difficult to form the network structure 24 in the functional film 20.
　また、ＣＮＴ３４は、直径約３０ｎｍ以下であるのが好ましい。ＣＮＴ３４は直径が３０ｎｍ以下であると、柔軟性に富んで変形しやすいので、ＣＮＴ分散液３０中で制約なしに存在することができる。一方、ＣＮＴ３４は直径が３０ｎｍ超であると、柔軟性がなくなるのでネットワーク構造２４を形成しにくくなる。ＣＮＴ３４は、直径２０ｎｍ以下であるのがより好ましい。 Also, the CNT 34 preferably has a diameter of about 30 nm or less. If the diameter of the CNT 34 is 30 nm or less, the CNT 34 is rich in flexibility and easily deforms, and therefore can exist in the CNT dispersion 30 without restriction. On the other hand, if the diameter of the CNT 34 exceeds 30 nm, the flexibility is lost and it becomes difficult to form the network structure 24. More preferably, the CNT 34 has a diameter of 20 nm or less.
　ＣＮＴ３４の長さおよび直径は、透過型電子顕微鏡（ＴＥＭ；Transmission Electron Microscope）写真を用いて測定した平均値とする。 The length and diameter of the CNT 34 are the average values measured using a transmission electron microscope (TEM) photo.
　電気伝導性等のＣＮＴ由来の特性の低下につながるので、ＣＮＴ３４の表面には欠損が少ないことが望まれる。ＣＮＴ３４表面の欠損は、カルボキシル基（－ＣＯＯＨ）、スルホン基（－ＳＯ３Ｈ）、ニトロ基（－ＮＯ２）、アルデヒド基（－ＣＨＯ）、アミノ基（－ＮＨ２）、および水酸基（－ＯＨ）等の官能基に起因し、官能基は表面処理によって付与される。従来のＣＮＴにおいては、ＣＮＴ分散液中での分散性を高める目的で表面に官能基が多く存在していた。本実施形態のＣＮＴ分散液３０に含有されるＣＮＴ３４は、表面処理が施されないため、官能基に起因する欠損は少ない。 Since the CNT-derived characteristics such as electrical conductivity are deteriorated, it is desired that the surface of the CNT 34 has few defects. Defects on the surface of CNT 34 are carboxyl group (—COOH), sulfone group (—SO 3 H), nitro group (—NO 2 ), aldehyde group (—CHO), amino group (—NH 2 ), and hydroxyl group (—OH). The functional group is imparted by a surface treatment. In the conventional CNT, many functional groups existed on the surface for the purpose of improving the dispersibility in the CNT dispersion. Since the CNTs 34 contained in the CNT dispersion 30 of the present embodiment are not subjected to surface treatment, there are few defects due to functional groups.
　本発明者らは、ＣＮＴ分散液３０の粘度ηについて検討した結果、せん断速度１００（１／ｓｅｃ）での粘度η１００（ｍＰａ・ｓ）と、せん断速度４００（１／ｓｅｃ）での粘度η４００（ｍＰａ・ｓ））との比（η１００／η４００）で表されるチキソ指数（ＴＩ値）と、ＣＮＴ分散液３０中のＣＮＴ濃度（体積％）との間の相関関係を見出した。 As a result of examining the viscosity η of the CNT dispersion 30, the present inventors have found that a viscosity η100 (mPa · s) at a shear rate of 100 (1 / sec) and a viscosity η400 (at a shear rate of 400 (1 / sec)) ( mPa · s)) and a thixo index (TI value) represented by a ratio (η100 / η400) and a CNT concentration (volume%) in the CNT dispersion 30 were found.
　本実施形態のＣＮＴ分散液３０においては、ＣＮＴ濃度ｘ（体積％）とＴＩ値ｙとの間に以下の式（１）、式（２）、式（３）および式（４）の関係が成立する。
　　　ｙ＞５ｘ＋１　　　　　　　　　（１）
　　　ｙ≦９．５ｘ＋１．３　　　　　（２）
　　　ｙ≦１７．４ｘ＋０．９３　　　（３）
　　　０．０１≦ｘ≦０．１５　　　　（４） In the CNT dispersion liquid 30 of the present embodiment, the following expressions (1), (2), (3), and (4) are present between the CNT concentration x (volume%) and the TI value y. To establish.
y> 5x + 1 (1)
y ≦ 9.5x + 1.3 (2)
y ≦ 17.4x + 0.93 (3)
0.01 ≦ x ≦ 0.15 (4)
　上記式（１）から、本実施形態のＣＮＴ分散液３０のＴＩ値ｙは、ｙ＝５ｘ＋１で表される直線より上方にあることがわかる。本実施形態に係るＣＮＴ３４は、長尺であってアスペクト比が大きいことにより、互いに絡み合いネットワーク構造２４を容易に形成するので、ＣＮＴ分散液３０の粘度を高くすることができる。本実施形態の場合、上記ネットワーク構造は、せん断応力を受けることにより、容易に解体され、ナノ分散する。したがってＣＮＴ分散液３０は、高回転で攪拌するなどしてＣＮＴ３４にせん断応力を加えると、粘度が下がる。このようにＣＮＴ分散液３０は、受けるせん断応力によって粘度が変化するので、大きいＴＩ値ｙを得ることができる。なお、本明細書において、「ナノ分散」とは、ＣＮＴ３４が１本ずつ物理的に分離して絡み合っていない状態で分散している状態をさし、２以上のＣＮＴ３４が束状に集合した集合物の割合が１０％以下である状態を意味する。 From the above formula (1), it can be seen that the TI value y of the CNT dispersion 30 of this embodiment is above the straight line represented by y = 5x + 1. Since the CNTs 34 according to the present embodiment are long and have a large aspect ratio, the network structure 24 is easily entangled with each other, so that the viscosity of the CNT dispersion 30 can be increased. In this embodiment, the network structure is easily disassembled and nano-dispersed by receiving shear stress. Accordingly, the viscosity of the CNT dispersion 30 decreases when a shear stress is applied to the CNTs 34 by stirring at a high speed. Thus, since the viscosity of the CNT dispersion liquid 30 changes depending on the shear stress received, a large TI value y can be obtained. In this specification, “nano-dispersion” means a state where CNTs 34 are physically separated and dispersed in a state where they are not entangled one by one. It means a state in which the proportion of objects is 10% or less.
　本実施形態のＣＮＴ分散液３０は、所定のＣＮＴ３４を分散媒３２中に分散させることによって調製することができる。 The CNT dispersion liquid 30 of this embodiment can be prepared by dispersing predetermined CNTs 34 in the dispersion medium 32.
　ＣＮＴ分散液３０の調製に用いられる原料ＣＮＴは、例えば、特開２００７－１２６３１１号公報に記載されているような熱ＣＶＤ法を用いてシリコン基板上にアルミニウム、鉄からなる触媒膜を成膜し、ＣＮＴの成長のための触媒金属を微粒子化し、加熱雰囲気中で炭化水素ガスを触媒金属に接触させることにより製造することができる。 The raw material CNT used for the preparation of the CNT dispersion 30 is obtained by forming a catalyst film made of aluminum or iron on a silicon substrate using a thermal CVD method as described in, for example, Japanese Patent Application Laid-Open No. 2007-12611. The catalyst metal for the growth of CNTs can be made fine and the hydrocarbon gas can be brought into contact with the catalyst metal in a heated atmosphere.
　アーク放電法、レーザ蒸発法などその他の製造方法により得たＣＮＴを使用することも可能であるが、ＣＮＴ以外の不純物を極力含まないものを使用することが好ましい。この不純物についてはＣＮＴを製造した後、不活性ガス中での高温アニールにより除去しても構わない。この製造例で製造したＣＮＴ３４は、直径が３０ｎｍ以下で長さが数１００μｍから数ｍｍという高いアスペクト比でもって直線的に配向された長尺である。ＣＮＴ３４は単層、多層を問わないが、多層が好ましい。 Although it is possible to use CNTs obtained by other manufacturing methods such as arc discharge method and laser evaporation method, it is preferable to use those which do not contain impurities other than CNTs as much as possible. These impurities may be removed by high-temperature annealing in an inert gas after the CNTs are manufactured. The CNTs 34 manufactured in this manufacturing example are long and linearly oriented with a high aspect ratio of a diameter of 30 nm or less and a length of several hundred μm to several mm. The CNT 34 may be a single layer or a multilayer, but a multilayer is preferable.
　分散媒３２は、樹脂を所定の濃度で所定の溶媒に溶解して、調製することができる。 The dispersion medium 32 can be prepared by dissolving the resin in a predetermined solvent at a predetermined concentration.
　ＣＮＴ分散液３０は、上記のようにして製造されたＣＮＴ３４を粉砕して分散媒３２に加え、湿式分散機、ホモジナイザー、超音波分散機などを用いて、分散媒３２中にＣＮＴ３４をナノ分散させて調製することができる。 The CNT dispersion 30 is obtained by pulverizing the CNTs 34 produced as described above and adding them to the dispersion medium 32, and then nano-dispersing the CNTs 34 in the dispersion medium 32 using a wet disperser, a homogenizer, an ultrasonic disperser, or the like. Can be prepared.
　ＣＮＴ３４は、所望の長さが得られ、表面の官能基が欠損とならない程度であれば、前処理を施してもよい。 The CNT 34 may be pretreated as long as a desired length is obtained and the functional groups on the surface are not lost.
　本実施形態においては、粘性液中における湿式分散を用いることが好ましい。湿式分散を用いることによって、ＣＮＴ同士の絡まり合いや、擦れによるＣＮＴの切断や損傷を防止することができる。 In this embodiment, it is preferable to use wet dispersion in a viscous liquid. By using wet dispersion, it is possible to prevent entanglement between the CNTs and cutting or damage of the CNTs due to rubbing.
　本実施形態のＣＮＴ分散液３０の調製には、分散剤、界面活性剤、チキソ付与剤（粘弾性調整剤）等の添加剤は必ずしも必要とされないが、本発明の効果に悪影響を及ぼさない範囲であれば、こうした添加剤を用いてもよい。 For the preparation of the CNT dispersion 30 of the present embodiment, additives such as a dispersant, a surfactant, a thixotropic agent (viscoelasticity modifier) and the like are not necessarily required, but do not adversely affect the effects of the present invention. If so, such additives may be used.
　上述したような本実施形態のＣＮＴ分散液３０を、所定の母材１２上にバーコート、スプレー、スピンコート、ナイフコート、ディップコート等により塗布する。塗布される際、ＣＮＴ分散液３０中のＣＮＴ３４は、せん断応力を受けることにより、ナノ分散している。塗布されるＣＮＴ分散液３０の量は、目的とする膜厚の機能性膜２０が得られるように調整することができる。 The CNT dispersion 30 of the present embodiment as described above is applied on a predetermined base material 12 by bar coating, spraying, spin coating, knife coating, dip coating, or the like. When applied, the CNTs 34 in the CNT dispersion 30 are nano-dispersed by receiving shear stress. The amount of the CNT dispersion 30 to be applied can be adjusted so that the functional film 20 having a target film thickness can be obtained.
　塗布後、せん断応力が小さくなるとＣＮＴ分散液３０中のＣＮＴ３４は、徐々に絡み合い、ネットワーク構造２４を形成し得る。塗布されたＣＮＴ分散液３０を乾燥させることによって、機能性膜２０を形成することができる。当該機能性膜２０において、ＣＮＴ３４はネットワーク構造２４を形成した状態で固定される。乾燥条件は、ＣＮＴ分散液３０中の分散媒３２に含有される樹脂および溶媒の種類に応じて、適宜設定すればよい。このようにして、本実施形態の複合素材１０が得られる。 After the application, when the shear stress becomes small, the CNTs 34 in the CNT dispersion 30 are gradually entangled to form the network structure 24. The functional film 20 can be formed by drying the applied CNT dispersion 30. In the functional film 20, the CNT 34 is fixed in a state where the network structure 24 is formed. What is necessary is just to set drying conditions suitably according to the kind of resin and solvent which are contained in the dispersion medium 32 in the CNT dispersion liquid 30. Thus, the composite material 10 of this embodiment is obtained.
［作用及び効果］
　本実施形態に係るＣＮＴ分散液３０においては、せん断速度１００（１／ｓｅｃ）での粘度η１００（ｍＰａ・ｓ）と、せん断速度４００（１／ｓｅｃ）での粘度η４００（ｍＰａ・ｓ））との比（η１００／η４００）と、ＣＮＴ濃度（体積％）との間に所定の相関関係が成立している。本実施形態に係るＣＮＴ分散液３０は、所定のＣＮＴ濃度において、所定値を超えるＴＩ値ｙを有する。 [Action and effect]
In the CNT dispersion 30 according to the present embodiment, the viscosity η100 (mPa · s) at a shear rate of 100 (1 / sec) and the viscosity η400 (mPa · s) at a shear rate of 400 (1 / sec)) A predetermined correlation is established between the ratio (η100 / η400) and the CNT concentration (volume%). The CNT dispersion 30 according to the present embodiment has a TI value y exceeding a predetermined value at a predetermined CNT concentration.
　このように本実施形態に係るＣＮＴ分散液３０は、高いＴＩ値ｙを有しているので、樹脂本来の特性を十分に維持しつつ、ＣＮＴ３４由来の特性が十分に発揮された機能性膜２０を形成することができる。 As described above, since the CNT dispersion 30 according to the present embodiment has a high TI value y, the functional film 20 that sufficiently exhibits the characteristics derived from the CNTs 34 while sufficiently maintaining the original characteristics of the resin. Can be formed.
　本実施形態のＣＮＴ分散液３０は、せん断応力を受けている場合、ＣＮＴ３４がナノ分散する。したがってＣＮＴ３４は、ＣＮＴ分散液３０を塗布する際、せん断応力を受けることにより、ナノ分散し、低濃度でも、母材１２表面に均一に塗布することができる。 In the CNT dispersion liquid 30 of this embodiment, the CNTs 34 are nano-dispersed when subjected to shear stress. Therefore, the CNT 34 is nano-dispersed by receiving shear stress when the CNT dispersion 30 is applied, and can be uniformly applied to the surface of the base material 12 even at a low concentration.
　そして、塗布後、せん断応力が低下することによって、徐々にＣＮＴ３４が互いに絡み合いネットワーク構造２４を形成していく。これによりＣＮＴ分散液３０は粘度が高くなるので、液だれ等が生じることを防止することができる。さらにＣＮＴ分散液３０が乾燥することにより、ＣＮＴ３４がネットワーク構造２４を形成した状態で固定された機能性膜２０を得ることができる。機能性膜２０は、ＣＮＴ３４が互いに絡み合ったネットワーク構造２４を備えているので、０．１～１００μｍ程度の膜厚でもＣＮＴ由来の優れた電気伝導性、機械強度が得られる。 Then, after application, the shear stress is lowered, so that the CNTs 34 are gradually entangled with each other to form the network structure 24. Thereby, since the viscosity of the CNT dispersion liquid 30 is increased, it is possible to prevent dripping or the like. Further, by drying the CNT dispersion liquid 30, it is possible to obtain the functional film 20 in which the CNTs 34 are fixed in a state where the network structure 24 is formed. Since the functional film 20 includes the network structure 24 in which the CNTs 34 are entangled with each other, excellent electrical conductivity and mechanical strength derived from CNTs can be obtained even with a film thickness of about 0.1 to 100 μm.
　ＣＮＴ分散液３０は、任意の母材１２の表面に機能性膜２０を設けることにより、ＣＮＴ３４由来の特性、すなわち電気伝導性、機械強度を有する複合素材１０を形成することができる。 The CNT dispersion 30 can form the composite material 10 having the characteristics derived from the CNTs 34, that is, electrical conductivity and mechanical strength, by providing the functional film 20 on the surface of an arbitrary base material 12.
［変形例］
　本発明は上記実施形態に限定されるものではなく、本発明の趣旨の範囲内で適宜変更することが可能である。例えば、上記本実施形態の機能性膜２０は、所定の支持体上に剥離可能に作製することもできる。複合素材１０の場合と同様の手法により支持体上に機能性膜２０を形成し、支持体から剥離した場合には、機能性膜２０を独立した単体として得ることも可能である。 [Modification]
The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the gist of the present invention. For example, the functional film 20 of the present embodiment can also be formed on a predetermined support so as to be peelable. When the functional film 20 is formed on the support by the same method as in the case of the composite material 10 and is peeled from the support, the functional film 20 can be obtained as an independent single body.
　上記本実施形態では、塗膜形成物が樹脂である場合について説明したが、本発明はこれに限らず、一般的な粘性体にも適用することもできる。 In the present embodiment, the case where the coating film formation is a resin has been described. However, the present invention is not limited to this and can be applied to a general viscous body.
［実施例］
　以下、実施例を挙げて本発明のＣＮＴ分散液、機能性膜および複合素材を詳細に説明するが、本発明は以下の実施例のみに限定されるものではない。 [Example]
Hereinafter, although an Example is given and the CNT dispersion liquid, functional film | membrane, and composite material of this invention are demonstrated in detail, this invention is not limited only to a following example.
＜ＣＮＴ分散液＞
　樹脂と溶媒とを含む分散媒に、所定の濃度でＣＮＴを分散させて、実施例１～７のＣＮＴ分散液を調製した。ここで用いたＣＮＴは、熱ＣＶＤ法によりシリコン基板上に成長させたＭＷ－ＣＮＴ（multi-walled Carbon Nanotubes、多層カーボンナノチューブ）であり、長さ３５０μｍ、直径１３ｎｍである。図４には、実施例で用いたＣＮＴの分散処理前のＳＥＭ写真を示す。実施例のＣＮＴ分散液の調製に用いたＣＮＴは、１本ずつ物理的に分離して、互いに絡み合うことなく存在していることがわかる。 <CNT dispersion>
CNT dispersions of Examples 1 to 7 were prepared by dispersing CNTs at a predetermined concentration in a dispersion medium containing a resin and a solvent. The CNTs used here are MW-CNTs (multi-walled carbon nanotubes) grown on a silicon substrate by a thermal CVD method, and have a length of 350 μm and a diameter of 13 nm. In FIG. 4, the SEM photograph before the dispersion | distribution process of CNT used in the Example is shown. It can be seen that the CNTs used in the preparation of the CNT dispersions of the examples are physically separated one by one and exist without being entangled with each other.
　ＣＮＴは表面処理を行わずに分散媒と混合し、湿式分散機を用いて分散媒に分散させた。分散剤およびチキソ付与剤（粘弾性調整剤）は、いずれも配合せず、湿式分散処理を１５回行って実施例のＣＮＴ分散液を得た。 CNT was mixed with a dispersion medium without performing surface treatment, and dispersed in the dispersion medium using a wet disperser. Neither a dispersant nor a thixotropic agent (viscoelasticity modifier) was blended, and wet dispersion treatment was performed 15 times to obtain a CNT dispersion of the example.
　また、市販のＣＮＴを所定の濃度で用いて、比較例１～８のＣＮＴ分散液を調製した。比較例１～３では、Ｎａｎｏｃｙｌ社製ＣＮＴ（製番ＮＣ７０００　長さ１．５μｍ、直径９．５ｎｍ）を用い、比較例４～６では、ＳＷｅＮＴ社製ＣＮＴ（製番ＳＭＷ２００　長さ３．５μｍ、直径１０ｎｍ）を用い、比較例７では、Ｃｎａｎｏ社製ＣＮＴ（製番FＦｌｏＴｕｂｅ９０１１　長さ１０μｍ、直径１１ｎｍ）を用い、比較例８では、ＪＥＩＯ社製ＣＮＴ（製番ＪＣ-４００　長さ１μｍ、直径２０ｎｍ）を用いた。上記比較例に係るＣＮＴの長さと直径の数値は、いずれもカタログ値である。 Also, CNT dispersions of Comparative Examples 1 to 8 were prepared using commercially available CNTs at a predetermined concentration. In Comparative Examples 1 to 3, Nanocyl CNT (product number NC7000, length 1.5 μm, diameter 9.5 nm) was used, and in Comparative Examples 4 to 6, SWeNT CNT (product number SMW200, length 3.5 μm, In Comparative Example 7, CNTs manufactured by Cano (product number FloTube 9011, length 10 μm, diameter 11 nm) were used. In Comparative Example 8, CNTs manufactured by JEIO (product number JC-400, length 1 μm, diameter 20 nm) were used. ) Was used. The numerical values of the length and the diameter of the CNT according to the comparative example are both catalog values.
　得られたＣＮＴ分散液中のＣＮＴの長さおよび直径を、ＴＥＭ観察により求めた。なお、実施例１～７のＣＮＴ分散液中のＣＮＴは、表面処理が施されていないので表面の官能基が少なく、表面の欠損が少ないことが推測される。 The length and diameter of CNT in the obtained CNT dispersion were determined by TEM observation. Note that the CNTs in the CNT dispersions of Examples 1 to 7 are presumed to have few surface functional groups and few surface defects because they are not surface-treated.
　実施例および比較例のＣＮＴ分散液について、２３℃における粘度を測定した。粘度の測定にはウエルズブルックフィールド・コーン/プレート型粘度計を用い、せん断速度を変化させて、１００／ｓｅｃの際の粘度（η１００）と、４００／ｓｅｃの際の粘度（η４００）とを求めた。（η１００／η４００）をチキソ指数（ＴＩ値）とする。 The viscosity at 23 ° C. was measured for the CNT dispersions of Examples and Comparative Examples. Viscosity was measured using a Wellsbrookfield cone / plate viscometer, and the shear rate was varied to determine the viscosity at 100 / sec (η100) and the viscosity at 400 / sec (η400). It was. Let (η100 / η400) be the thixo index (TI value).
　実施例および比較例のＣＮＴ分散液に含有されるＣＮＴおよび分散媒を、ＣＮＴ分散液の粘度およびＴＩ値とともに、下記表１にまとめる。表１中、ＮＭＰはＮ－メチル－２ピロリドンの略であり、ＰＶＰおよびＰＩは、それぞれポリビニルピロリドンおよびポリイミドの略である。また、樹脂の（体積％）は、分散媒全体における濃度である。 Table 1 below summarizes the CNTs and dispersion media contained in the CNT dispersions of Examples and Comparative Examples, together with the viscosity and TI value of the CNT dispersions. In Table 1, NMP is an abbreviation for N-methyl-2pyrrolidone, and PVP and PI are abbreviations for polyvinylpyrrolidone and polyimide, respectively. Moreover, (volume%) of resin is the density | concentration in the whole dispersion medium.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　上記表１に示されるように、実施例１～７のＣＮＴ分散液に含有されているＣＮＴは、１～１００μｍ程度と長いものである。ここで、長さが２０μｍ程度のＣＮＴは、１０００を超える大きなアスペクト比を有する。 As shown in Table 1, the CNTs contained in the CNT dispersions of Examples 1 to 7 are as long as about 1 to 100 μm. Here, the CNT having a length of about 20 μm has a large aspect ratio exceeding 1000.
　一方、比較例１～８のＣＮＴ分散液に含有されているのは、長さが０．１～１μｍ程度で、アスペクト比が最大でも１００程度と小さなＣＮＴである。比較例１～３で用いたＣＮＴ、比較例４～６で用いたＣＮＴ、比較例７で用いたＣＮＴ、および比較例８で用いたＣＮＴについて、分散処理前のＳＥＭ写真を図５～８にそれぞれ示す。比較例で用いたＣＮＴには、個々のＣＮＴが絡み合って形成された島状の凝集体１４０～１４３が確認される。 On the other hand, the CNT dispersions of Comparative Examples 1 to 8 contain CNTs having a length of about 0.1 to 1 μm and a small aspect ratio of about 100 at the maximum. 5 to 8 show SEM photographs before dispersion treatment for the CNT used in Comparative Examples 1 to 3, the CNT used in Comparative Examples 4 to 6, the CNT used in Comparative Example 7, and the CNT used in Comparative Example 8. Each is shown. In the CNT used in the comparative example, island-shaped aggregates 140 to 143 formed by entanglement of individual CNTs are confirmed.
　実施例のＣＮＴ分散液は、アスペクト比の高いＣＮＴを用いて調製されたものである。分散処理を施すことによってＣＮＴは短尺化するが、それでも実施例のＣＮＴ分散液には、２０μｍ程度と長く、１０００を超える非常にアスペクト比の大きなＣＮＴが含有される。 The CNT dispersion liquid of the examples is prepared using CNT having a high aspect ratio. Although the CNTs are shortened by carrying out the dispersion treatment, the CNT dispersion liquid of the example still has a length as long as about 20 μm and contains CNTs having a very large aspect ratio exceeding 1000.
　比較例のＣＮＴ分散液は、絡み合って凝集した凝集体を含むＣＮＴを用いて調製されたものである。 The CNT dispersion of the comparative example was prepared using CNT containing aggregates that were entangled and aggregated.
　上記表１に記載したＣＮＴ濃度（体積％）およびＴＩ値を、それぞれｘ軸およびｙ軸として、その関係を図９のグラフに示す。 FIG. 9 is a graph showing the relationship between the CNT concentration (volume%) and the TI value described in Table 1 above as the x-axis and y-axis, respectively.
　図９のグラフ中の比較例１～８について、ＣＮＴ濃度ｘ（体積％）とＴＩ値ｙとの関係は、下記式（１１）で表すことができる。
　　　　ｙ＝５．０ｘ＋１　　　　（１１） For Comparative Examples 1 to 8 in the graph of FIG. 9, the relationship between the CNT concentration x (volume%) and the TI value y can be expressed by the following equation (11).
y = 5.0x + 1 (11)
　ＣＮＴ濃度ｘ（体積％）とＴＩ値ｙとの関係は、実施例１，２については下記式（１２）で表すことができ、実施例３～７については、下記式（１３）で表すことができる。
　　　ｙ＝９．５ｘ＋１．３　　　　　（１２）
　　　ｙ＝１７．４ｘ＋０．９３　　　（１３） The relationship between the CNT concentration x (volume%) and the TI value y can be expressed by the following formula (12) for Examples 1 and 2 and expressed by the following formula (13) for Examples 3 to 7. Can do.
y = 9.5x + 1.3 (12)
y = 17.4x + 0.93 (13)
　実施例３～７については、下記式（１７）で表すこともできる。
　　　ｙ＝１４ｘ＋０．９５　　　　　（１７） Examples 3 to 7 can also be represented by the following formula (17).
y = 14x + 0.95 (17)
　図９に示されるように、同一のＣＮＴ濃度について比較すると、実施例のＣＮＴ分散液は、比較例のＣＮＴ分散液よりＴＩ値ｙが大きい。 As shown in FIG. 9, when compared with the same CNT concentration, the CNT dispersion liquid of the example has a larger TI value y than the CNT dispersion liquid of the comparative example.
　上述したように、実施例のＣＮＴ分散液には、長さが２０μｍ程度でアスペクト比が高いＣＮＴが含有されている。実施例のＣＮＴ分散液は、ＣＮＴが長尺であってアスペクト比が大きいことにより、せん断応力が小さい場合、互いに絡み合いネットワーク構造２４を容易に形成するので、粘度を高くすることができる。また、実施例のＣＮＴ分散液は、せん断応力を受けることにより、ネットワーク構造が容易に解体され、ＣＮＴがナノ分散するので、粘度が下がる。このように実施例のＣＮＴ分散液は、受けるせん断応力によって粘度が変化するので、大きいＴＩ値ｙを得ることができる。したがって、実施例のＣＮＴ分散液においては、ＣＮＴ濃度（体積％）とＴＩ値ｙとの間に図９に示すような相関関係が得られた。分散処理を施すことによってＣＮＴは短尺化するので、実施例のＣＮＴ分散液を調製する際、ＣＮＴのアスペクト比を小さくすることもできる。ＣＮＴのアスペクト比が小さくなると、せん断応力が小さい場合の粘度を低くすることができるので、ＣＮＴ分散液のＴＩ値ｙも小さくなる。言い換えると、上記式（１２）および式（１３）は、実施例のＣＮＴ分散液のＴＩ値ｙの上限に相当する。また実施例のＣＮＴ分散液は、ＣＮＴの長さ及びアスペクト比を調整することにより、より小さいＴＩ値ｙを得ることができる。 As described above, the CNT dispersion liquid of the example contains CNT having a length of about 20 μm and a high aspect ratio. Since the CNT dispersion liquid of the example is long and has a large aspect ratio, when the shear stress is small, the CNT dispersion liquid entangles each other and easily forms the network structure 24, so that the viscosity can be increased. In addition, the CNT dispersion liquid of the example is subjected to shear stress, so that the network structure is easily disassembled and the CNTs are nano-dispersed, so that the viscosity decreases. Thus, since the viscosity of the CNT dispersion liquid of the example changes depending on the shear stress received, a large TI value y can be obtained. Therefore, in the CNT dispersion liquid of the example, a correlation as shown in FIG. 9 was obtained between the CNT concentration (volume%) and the TI value y. Since the CNTs are shortened by carrying out the dispersion treatment, the aspect ratio of the CNTs can be reduced when preparing the CNT dispersions of the examples. When the aspect ratio of the CNT is reduced, the viscosity when the shear stress is small can be reduced, so that the TI value y of the CNT dispersion is also reduced. In other words, the above formulas (12) and (13) correspond to the upper limit of the TI value y of the CNT dispersion liquid of the example. Moreover, the CNT dispersion liquid of an Example can obtain smaller TI value y by adjusting the length and aspect ratio of CNT.
　以上に基づくと、実施例のＣＮＴ分散液においては、ＣＮＴ濃度ｘ（体積％）とチキソ指数（ＴＩ値ｙ）との間には、次の関係が成立することがわかる。
　　　ｙ＞５ｘ＋１　　　　　　　　　（１）
　　　ｙ≦９．５ｘ＋１．３　　　　　（２）
　　　ｙ≦１７．４ｘ＋０．９３　　　（３）
　　　０．０１≦ｘ≦０．１５　　　　（４） Based on the above, it can be seen that the following relationship is established between the CNT concentration x (volume%) and the thixo index (TI value y) in the CNT dispersion liquid of the example.
y> 5x + 1 (1)
y ≦ 9.5x + 1.3 (2)
y ≦ 17.4x + 0.93 (3)
0.01 ≦ x ≦ 0.15 (4)
　すなわち、実施例のＣＮＴ分散液は、上記式（１）、式（２）、式（３）および式（４）の関係を満足するものである。なお、本実施例では、少なくともＣＮＴ濃度が０．１５（体積％）までは、ＴＩ値ｙを高くしながら長尺のＣＮＴを分散させることができることを確認した。ＣＮＴ分散液中におけるＣＮＴ濃度ｘが０．０１（体積％）以上であれば、こうした関係が成立する。 That is, the CNT dispersion liquid of the example satisfies the relationships of the above formulas (1), (2), (3), and (4). In this example, it was confirmed that long CNTs could be dispersed while increasing the TI value y at least until the CNT concentration was 0.15 (volume%). This relationship is established if the CNT concentration x in the CNT dispersion is 0.01 (% by volume) or more.
　これに対し比較例のＣＮＴ分散液は、図９に示されるようにＴＩ値ｙが１．１～１．３９程度（ｙ≦５ｘ＋１）と低いものとなった。図５～８に示したように、比較例で用いたＣＮＴは絡まり合って凝集体１４０～１４３を形成している。このように比較例のＣＮＴ分散液中には凝集体が多く、本来、ネットワーク構造をとるのに有効なＣＮＴが少ない。仮に、せん断応力を受けても、当該凝集体となっているＣＮＴは短尺化して、アスペクト比の小さいＣＮＴとなる。こうしたＣＮＴが分散しても、ネットワーク構造をとりづらい。したがって比較例のＣＮＴ分散液は、受けるせん断応力によって粘度の変化が小さくＴＩ値ｙが低くなったと考えられる。 In contrast, the CNT dispersion of the comparative example had a low TI value y of about 1.1 to 1.39 (y ≦ 5x + 1) as shown in FIG. As shown in FIGS. 5 to 8, the CNTs used in the comparative example are entangled to form aggregates 140 to 143. As described above, the CNT dispersion liquid of the comparative example has many aggregates, and originally, there are few CNTs effective for taking a network structure. Even if shear stress is applied, the aggregated CNTs are shortened to become CNTs having a small aspect ratio. Even if such CNTs are dispersed, it is difficult to adopt a network structure. Therefore, it is considered that the CNT dispersion liquid of the comparative example has a small change in viscosity due to the shear stress received and a low TI value y.
　なお、ＣＮＴ分散液のＴＩ値ｙは、ＣＮＴの表面と分散媒中の溶媒との親和性にも依存する。例えば、ＣＮＴの表面の親水性が高い場合には、溶媒として水が含有される際にＴＩ値ｙが高くなり、ＣＮＴの表面の親油性が高い場合には、溶媒として有機溶剤が含有される際にＴＩ値ｙが高くなる。 Note that the TI value y of the CNT dispersion also depends on the affinity between the CNT surface and the solvent in the dispersion medium. For example, when the hydrophilicity of the CNT surface is high, the TI value y is high when water is contained as the solvent, and when the lipophilicity of the CNT surface is high, an organic solvent is contained as the solvent. At this time, the TI value y increases.
　樹脂としてＰＶＰを用いた実施例１，２においては、溶媒として水が用いられている。樹脂としてＰＩを用いた実施例３～７においては、有機溶剤が用いられている。実施例のＣＮＴ分散液では、水および有機溶剤のいずれが用いられた場合でも、高いＴＩ値ｙが得られることが図９に示されており、ＴＩ値ｙはＣＮＴ表面の溶媒との親和性とは無関係である。本実施形態のＣＮＴ分散液は、大きいせん断応力受けると、容易にネットワーク構造を解体し得るＣＮＴを含むことにより、高いＴＩ値ｙが得られる。 In Examples 1 and 2 using PVP as the resin, water is used as the solvent. In Examples 3 to 7 using PI as the resin, an organic solvent is used. In the CNT dispersion liquid of the example, it is shown in FIG. 9 that a high TI value y can be obtained regardless of whether water or an organic solvent is used. The TI value y is compatible with the solvent on the CNT surface. It has nothing to do with it. When the CNT dispersion liquid of this embodiment is subjected to a large shear stress, a high TI value y is obtained by including CNT that can easily disassemble the network structure.
　以上においては、樹脂としてＰＶＰを含有する分散媒と、ＰＩを含有する分散媒との２種類の分散媒を用いたＣＮＴ分散液について説明したが、本実施形態のＣＮＴ分散液はこれらに限定されるものではない。長さ１～１００μｍのＣＮＴが含有されていれば、ＣＮＴ濃度（体積％）とＴＩ値ｙとの相関関係は、他の樹脂を含む分散媒を用いたＣＮＴ分散液の場合も同様の傾向となる。 In the above description, the CNT dispersion using two types of dispersion media, that is, a dispersion medium containing PVP as a resin and a dispersion medium containing PI has been described. However, the CNT dispersion liquid of the present embodiment is not limited to these. It is not something. If CNTs with a length of 1 to 100 μm are contained, the correlation between the CNT concentration (% by volume) and the TI value y is similar to that in the case of a CNT dispersion using a dispersion medium containing other resins. Become.
＜機能性膜の表面抵抗率＞
　実施例３のＣＮＴ分散液を、Ｋハンドコーターにより母材上に塗布して塗膜を形成した。ここでの母材としては、ガラス基板を用いた。ホットプレートを用い、９０℃で３０分間乾燥させた後２５０℃で３０分間焼成して、所定の膜厚の機能性膜を形成した。得られた機能性膜の表面抵抗率を四探針抵抗率計により測定し、その結果を図１０のグラフにプロットした。 <Surface resistivity of functional film>
The CNT dispersion liquid of Example 3 was applied onto the base material with a K hand coater to form a coating film. A glass substrate was used as the base material here. Using a hot plate, the film was dried at 90 ° C. for 30 minutes and then baked at 250 ° C. for 30 minutes to form a functional film having a predetermined film thickness. The surface resistivity of the obtained functional film was measured with a four-probe resistivity meter, and the result was plotted in the graph of FIG.
　図１０に示されるように、実施例３の分散液を用いて形成された機能性膜は、１０μｍ程度の厚さで（１．０Ｅ＋３．５）Ω／sq程度の表面抵抗率が得られることがわかる。ここで形成された機能性膜は、ＣＮＴ由来の電気伝導性が塗膜（ポリイミド層）に付与された導電膜である。 As shown in FIG. 10, the functional film formed using the dispersion liquid of Example 3 has a surface resistivity of about (1.0E + 3.5) Ω / sq with a thickness of about 10 μm. I understand. The functional film formed here is a conductive film in which electrical conductivity derived from CNT is imparted to the coating film (polyimide layer).
　比較例１～８のＣＮＴ分散液を用いて同様の厚さの機能性膜を形成し、表面抵抗率を測定したところ、いずれも（６．０Ｅ＋３）Ω／sq以上であった。（１．０Ｅ＋３．５）Ω／sq程度の表面抵抗率を得るには、比較例のＣＮＴ分散液を用いた機能性膜は、実施例３の５倍程度以上の厚さで形成する必要があった。 When a functional film having the same thickness was formed using the CNT dispersion liquids of Comparative Examples 1 to 8 and the surface resistivity was measured, all were (6.0E + 3) Ω / sq or more. In order to obtain a surface resistivity of about (1.0E + 3.5) Ω / sq, the functional film using the CNT dispersion liquid of the comparative example needs to be formed with a thickness of about 5 times or more that of Example 3. there were.
　比較例のＣＮＴ分散液は、せん断応力を受けてもＣＮＴの凝集体が解体されないので、同じＣＮＴ濃度で比較した場合、実施例のＣＮＴ分散液よりＴＩ値ｙが小さい。比較例のＣＮＴ分散液で形成された機能性膜では、ＣＮＴがネットワーク構造を形成することができないので、薄い膜厚でＣＮＴの特性（電気伝導性）を十分に発揮した機能性膜を形成することができない。 The CNT dispersion of the comparative example does not disassemble CNT aggregates even when subjected to shear stress. Therefore, when compared at the same CNT concentration, the TI value y is smaller than that of the CNT dispersion of the example. In the functional film formed with the CNT dispersion liquid of the comparative example, since the CNT cannot form a network structure, a functional film that sufficiently exhibits the characteristics (electric conductivity) of the CNT is formed with a thin film thickness. I can't.
　図１１は、上述の手法により母材上に形成された機能性膜の表面のＳＥＭ写真である。図１１のＳＥＭ写真によれば、長さが２．５μｍ以上のＣＮＴが多量に存在しており、ＣＮＴが束状に集合した集合物や凝集体の存在が少ないことが分かる。ここでいうＣＮＴ長さは膜表面付近に存在するＣＮＴの一部分の長さであり、全体長さではないため、実際にはより長尺であることが推測される。ＣＮＴが長尺であること、ＣＮＴ表面の欠損が少ないことに起因して、機能性膜の電気伝導性が向上したものと推測される。 FIG. 11 is an SEM photograph of the surface of the functional film formed on the base material by the method described above. According to the SEM photograph of FIG. 11, it can be seen that a large amount of CNT having a length of 2.5 μm or more is present, and there are few aggregates and aggregates in which the CNTs are gathered in a bundle. The CNT length here is the length of a part of the CNT existing in the vicinity of the film surface, not the entire length, so it is estimated that it is actually longer. It is presumed that the electrical conductivity of the functional film has been improved due to the fact that the CNTs are long and there are few defects on the CNT surface.
　以上の結果から、実施例３のＣＮＴ分散液を用いることによって、膜厚が１０μｍ程度という薄い機能性膜であっても、高い電気伝導性が得られることがわかる。 From the above results, it can be seen that by using the CNT dispersion liquid of Example 3, high electrical conductivity can be obtained even with a thin functional film having a film thickness of about 10 μm.
＜膜の引掻き強度＞
　実施例３のＣＮＴ分散液をスプレー塗工により母材上に塗布した。ここでの母材としては、ステンレスを用いた。乾燥機を用いて２００℃で３０分乾燥し、３００℃で３０分イミド化を行った。膜厚１７～１８μｍの機能性膜を形成した。また、比較として、ＣＮＴを配合せず分散媒のみを用いて、同様の厚さで薄膜（ポリイミド膜）を形成した。 <Scratch strength of film>
The CNT dispersion liquid of Example 3 was applied onto the base material by spray coating. Stainless steel was used as the base material here. It dried at 200 degreeC for 30 minutes using the dryer, and imidation was performed at 300 degreeC for 30 minutes. A functional film having a thickness of 17 to 18 μm was formed. For comparison, a thin film (polyimide film) having the same thickness was formed using only the dispersion medium without blending CNTs.
　得られた機能性膜および薄膜に対して任意の荷重をかけた引掻き針により強度測定を行った。それぞれの膜が母材から剥離した際の強度を比較する。なお、用いた試験機はヘイドン摩擦測定機であり、引掻き針はサファイア製（０．０５ｍｍ、Ｒ６０°）、引掻き速度は２０ｍｍ／ｍｉｎとした。 The strength was measured with a scratching needle with an arbitrary load applied to the obtained functional film and thin film. The strength when each film peels from the base material is compared. The testing machine used was a Haydon friction measuring machine, the scratching needle was made of sapphire (0.05 mm, R60 °), and the scratching speed was 20 mm / min.
　実施例３のＣＮＴ分散液を用いた機能性膜は、０．９８Ｎで削れが発生したものの、２．４５Ｎまで裂けが生じることはなく、引掻き強度が向上したことが確認された。一方、比較としてのポリイミド膜は、０．９８Ｎで削れが発生し、１．４７Ｎで裂けてしまった。 Although the functional film using the CNT dispersion liquid of Example 3 was scraped at 0.98 N, it was confirmed that the scratch strength was improved without tearing to 2.45 N. On the other hand, the comparative polyimide film was scraped at 0.98N and was torn at 1.47N.
　以上の結果から、実施例３のＣＮＴ分散液を用いることによって、引掻き強度の高い機能性膜を形成できることがわかった。また本実施形態のＣＮＴ分散液を用いて得られる機能性膜は、ＣＮＴが均一に分散されネットワーク構造２４を形成しているので、靱性も向上することが推測される。 From the above results, it was found that a functional film having high scratch strength can be formed by using the CNT dispersion liquid of Example 3. In addition, the functional film obtained using the CNT dispersion liquid of the present embodiment is supposed to improve toughness because CNTs are uniformly dispersed to form the network structure 24.
　１０　複合素材
　１２　母材
　２０　機能性膜
　２２　塗膜
　２４　ネットワーク構造
　３０　カーボンナノチューブ（ＣＮＴ）分散液
　３２　分散媒
　３４　カーボンナノチューブ（ＣＮＴ） DESCRIPTION OF SYMBOLS 10 Composite material 12 Base material 20 Functional film | membrane 22 Coating film 24 Network structure 30 Carbon nanotube (CNT) dispersion liquid 32 Dispersion medium 34 Carbon nanotube (CNT)

Claims (4)

  1. 　塗膜形成物および溶媒を含む分散媒と、
    　前記分散媒に分散されたカーボンナノチューブと
    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濃度ｘ（体積％）と、チキソ指数ｙ（η１００／η４００）とが、下記式（１）、式（２）、式（３）および式（４）の関係を満足することを特徴とするカーボンナノチューブ分散液。
    　　　ｙ＞５ｘ＋１　　　　　　　　　（１）
    　　　ｙ≦９．５ｘ＋１．３　　　　　（２）
    　　　ｙ≦１７．４ｘ＋０．９３　　　（３）
    　　　０．０１≦ｘ≦０．１５　　　　（４）
    （前記η１００はせん断速度１００（１／ｓｅｃ）における粘度（ｍＰａ・ｓ）であり、η４００はせん断速度４００（１／ｓｅｃ）における粘度（ｍＰａ・ｓ）である。）     A dispersion medium containing a film-forming product and a solvent;
    A carbon nanotube dispersion containing carbon nanotubes dispersed in the dispersion medium,
    The concentration x (volume%) of the carbon nanotube and the thixo index y (η100 / η400) satisfy the relationship of the following formulas (1), (2), (3), and (4). Characteristic carbon nanotube dispersion.
    y> 5x + 1 (1)
    y ≦ 9.5x + 1.3 (2)
    y ≦ 17.4x + 0.93 (3)
    0.01 ≦ x ≦ 0.15 (4)
    (Η100 is the viscosity (mPa · s) at a shear rate of 100 (1 / sec), and η400 is the viscosity (mPa · s) at a shear rate of 400 (1 / sec).)
  2. 　前記カーボンナノチューブは、長さが１～１００μｍであることを特徴とする請求項１記載のカーボンナノチューブ分散液。 2. The carbon nanotube dispersion liquid according to claim 1, wherein the carbon nanotube has a length of 1 to 100 μm.
  3. 　請求項１または２に記載のカーボンナノチューブ分散液を用いて形成されたことを特徴とする機能性膜。 A functional film formed using the carbon nanotube dispersion liquid according to claim 1 or 2.
  4. 　母材と、
    　前記母材の表面を被覆する請求項３に記載の機能性膜と
    を備えることを特徴とする複合素材。     With the base material,
    A composite material comprising the functional film according to claim 3 covering a surface of the base material.
PCT/JP2015/082064 2014-11-17 2015-11-16 Carbon nanotube dispersion, functional film, and composite material WO2016080327A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111247095A (en) * 2017-10-30 2020-06-05 霓达株式会社 Carbon nanotube dispersion and method for producing same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5775960B1 (en) * 2014-11-17 2015-09-09 ニッタ株式会社 Carbon nanotube dispersion, functional membrane and composite material

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007052739A1 (en) * 2005-11-04 2007-05-10 Kyushu University, National University Corporation Solubilization of carbon nanotube using aromatic polyimide
WO2009098779A1 (en) * 2008-02-08 2009-08-13 Meijo Nano Carbon Co., Ltd. Carbon nanotube dispersion and utilization of the same
JP5775960B1 (en) * 2014-11-17 2015-09-09 ニッタ株式会社 Carbon nanotube dispersion, functional membrane and composite material

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7279247B2 (en) * 2004-01-09 2007-10-09 The Board Of Regents Of The University Of Oklahoma Carbon nanotube pastes and methods of use
JP5537445B2 (en) * 2011-01-07 2014-07-02 ニッタ株式会社 CNT isolation dispersion
JP5919018B2 (en) * 2012-02-13 2016-05-18 ニッタ株式会社 Vinylon fiber containing carbon nanotube and method for producing the same
JP6135218B2 (en) * 2013-03-18 2017-05-31 宇部興産株式会社 Fine carbon fiber dispersion and method for producing the same
JP5960178B2 (en) * 2013-03-28 2016-08-02 富士フイルム株式会社 Method for producing thermoelectric conversion element and method for producing dispersion for thermoelectric conversion layer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007052739A1 (en) * 2005-11-04 2007-05-10 Kyushu University, National University Corporation Solubilization of carbon nanotube using aromatic polyimide
WO2009098779A1 (en) * 2008-02-08 2009-08-13 Meijo Nano Carbon Co., Ltd. Carbon nanotube dispersion and utilization of the same
JP5775960B1 (en) * 2014-11-17 2015-09-09 ニッタ株式会社 Carbon nanotube dispersion, functional membrane and composite material

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
HIROYUKI NISHIMURA ET AL., CARBON NANOTUBES (CNT) NO BUNSAN'EKI TO SONO OYO TENKAI <CNT- POLYIMIDE FUKUGOTAI ENO OYO JIREI O CHUSHIN NI>, vol. 62, no. 8, 2011, pages 40 - 45 *
SHIGETA, M. ET AL.: "Individual solubilization of single-walled carbon nanotubes using totally aromatic polyimide", CHEMICAL PHYSICS LETTERS, vol. 418, 2006, pages 115 - 118, XP025013149, DOI: doi:10.1016/j.cplett.2005.10.088 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111247095A (en) * 2017-10-30 2020-06-05 霓达株式会社 Carbon nanotube dispersion and method for producing same
CN111247095B (en) * 2017-10-30 2023-09-05 霓达株式会社 Carbon nanotube dispersion and method for producing the same

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