WO2019093360A1 - Carbon nanowire dispersion liquid and method for producing same - Google Patents

Carbon nanowire dispersion liquid and method for producing same Download PDF

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WO2019093360A1
WO2019093360A1 PCT/JP2018/041299 JP2018041299W WO2019093360A1 WO 2019093360 A1 WO2019093360 A1 WO 2019093360A1 JP 2018041299 W JP2018041299 W JP 2018041299W WO 2019093360 A1 WO2019093360 A1 WO 2019093360A1
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carbon
dispersion liquid
less
nanowire dispersion
carbon nanowire
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PCT/JP2018/041299
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French (fr)
Japanese (ja)
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成久 秋澤
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Ａｃａ株式会社
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    • 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
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/02—Printing inks
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/52—Electrically conductive inks
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D201/00—Coating compositions based on unspecified macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/24—Electrically-conducting paints
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/60—Additives non-macromolecular
    • C09D7/61—Additives non-macromolecular inorganic
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
    • D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
    • D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof

Definitions

  • the present invention relates to a dispersion in which carbon nanowires having a specific shape are dispersed, a method for producing the same, and a paint or ink obtained from the dispersion.
  • CFRP carbon fiber reinforced plastics
  • the shortest carbon fiber is also referred to as milled fiber, and in general, the average fiber length is 70 ⁇ m or more and 200 ⁇ m or less, and the average fiber diameter is about 10 ⁇ m. It is often used.
  • CFRP and so-called "carbon fibers” are considered to be less useful because their processability becomes more difficult and they tend to aggregate as they become shorter, and there are documents in which the fiber diameter and aspect ratio of carbon fibers are described.
  • nano-sized carbon fibers having a smaller size than milled fibers are not in reality. That is, at present, the demand and utilization of nano-sized carbon fibers are extremely low, particularly nano-sized carbon fibers having a large aspect ratio are not (commercially) present in the market, and at least such carbon fibers are stable. There are no known dispersions in dispersion.
  • nano-sized carbon fibers were not present for conductivity because nanoparticles such as carbon nanotubes, silver, copper, etc. are on the market and are generally available. Be In addition, although it is considered that nano-sized carbon fibers can be used for various applications requiring conductivity etc., dispersions of carbon fibers having a small average fiber diameter and an extremely large aspect ratio The fluid was unknown.
  • JP 7-118440 A Japanese Patent Laid-Open No. 2000-254919 JP 2001-030245 A JP, 2009-138143, A JP 2012-188790 A Unexamined-Japanese-Patent No. 2017-066546
  • the present invention has been made in view of the above background art, and the problem is that, in carbon fibers having an average fiber diameter of nanosize, the average fiber length is longer as compared to the fineness of the average fiber diameter, that is, the aspect ratio It is an object of the present invention to provide a carbon nanowire dispersion liquid which is easy to be easily crushed and dispersed in the dispersion medium and hardly reaggregated, and a method for producing the same.
  • CFRP carbon fiber reinforced plastic
  • the present invention is a carbon nanowire dispersion liquid characterized in that a carbon nanowire having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 to 200 is dispersed in a dispersion medium.
  • the present invention is also a method for producing the above-mentioned carbon nanowire dispersion liquid, A carbon nanowire dispersion liquid in which carbon fibers are dispersed in the dispersion medium by pulverizing the carbon fibers in a dry state or preparing a dry-ground carbon fiber and then grinding the carbon fibers in the dispersion medium by wet grinding.
  • a manufacturing method In the wet grinding, the dry ground carbon fiber is contained in the dispersion medium, and the carbon fiber is subjected to bead milling in the presence of an anionic surfactant, whereby the carbon fiber has an average fiber diameter of 300 nm or less and an average
  • the present invention provides a method for producing a carbon nanowire dispersion liquid, which has an aspect ratio of 30 or more and 200 or less.
  • the present invention provides a method for producing the above-mentioned carbon nanowire dispersion liquid, wherein the above-mentioned anionic surfactant is an alkali metal salt or alkylol ammonium salt of a (co) polymer having an acid group. It is.
  • the present invention provides a method for producing a carbon nanowire dispersion as described above, wherein the dispersion medium is water or "2-pyrrolidone in which the nitrogen atom may be substituted with a hydrocarbon group". is there.
  • the present invention also provides a carbon nanowire dispersion liquid, which is characterized by being manufactured by the above method of manufacturing a carbon nanowire dispersion liquid.
  • the present invention provides a paint or ink characterized in that the dispersion medium of the carbon nanowire dispersion described above is water, and further containing at least a water-soluble polymer therein. is there.
  • the dispersion medium of the above-mentioned carbon nanowire dispersion liquid is “2-pyrrolidone in which a nitrogen atom may be substituted with a hydrocarbon group”, and at least polyimide is further contained therein. It provides a paint or ink characterized by a certain thing.
  • a carbon nanowire dispersion liquid in which carbon nanowires having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 or more and 200 or less are dispersed in a dispersion medium has not been known so far and is novel It is.
  • the method for producing a carbon nanowire dispersion liquid of the present invention it is possible to preferably grind to a specific nano-sized shape having a large average aspect ratio, and more preferably to disperse it in a dispersion medium, The obtained dispersion is also extremely excellent in dispersion stability.
  • the carbon nanowires dispersed in the carbon nanowire dispersion liquid of the present invention are closer in shape to so-called silver nanowires and carbon nanotubes than so-called carbon nanofibers (CNF). Therefore, the carbon nanowires in the present invention are chemically structurally graphite, but are close to silver nanowires in shape, so they are suitably used in applications similar to those where silver nanowires are currently used. Be done. Moreover, the carbon nanowires in the carbon nanowire dispersion liquid of the present invention are extremely inexpensive (can be manufactured inexpensively) than silver nanowires (150,000 yen / g).
  • the carbon nanowire in the present invention has a small average diameter to the extent that light does not scatter and has a low electrical resistivity, it is expected to be used for transparent conductive films and the like. Further, since it is a dispersion, it can be suitably used not only for applications (fields) by vapor deposition, CVD, etc., but for applications (fields) where it is applied as a dispersion to form films, layers, wires, etc. That is, it can be suitably used as, for example, “various paints, various printing inks, etc.” of conductivity, heat conductivity, heat dissipation, rust prevention, jet blackness.
  • the dispersion is in the form of wires instead of particles, that is, the average fiber diameter is nano size and the aspect ratio is large, a substrate having micro-sized voids (paper; substrate such as polyimide film; etc.)
  • paper substrate such as polyimide film; etc.
  • the dispersion goes into the voids and does not show sufficient conductivity. That is, since the average fiber length is sufficiently long, a network of carbon nanowires is formed on the substrate without flowing into the void.
  • a film, a layer, a wiring or the like formed by, for example, coating, printing or the like using the carbon nanowire dispersion liquid of the present invention has high conductivity even if the thickness is thin.
  • the aspect ratio is large even when the substrate is bent or bent, the network of carbon nanowires is less likely to be broken, and the conductivity can be maintained. Therefore, it can apply especially suitably to deformable substrates, such as a flexible substrate.
  • the coated surface is turned to the outside by 180 °, for example, conductivity, heat conductivity, heat dissipation, rust prevention, and jet blackness can be secured on the entire surface.
  • the conductivity since the conductivity is ensured even at the bent portion, it is possible to produce a "structured body made of folded origami or flexible film" which is entirely conductive.
  • the carbon nanowire dispersion liquid of the present invention is particularly useful as a material of the wiring of the wiring substrate.
  • the wiring formed by printing etc. using the carbon nanowire dispersion liquid of this invention has electroconductivity, it can use this wiring as a cathode and can apply electrolytic metal plating further on that, By doing this, a printed wiring board having a normal conductor thickness (wiring thickness) can be produced.
  • a printed wiring board having a normal conductor thickness (wiring thickness) can be produced.
  • an electrolytic copper plating solution is used as the electrolytic metal plating solution, it is possible to produce a copper wiring with an arbitrary thickness on a substrate.
  • the conductive circuit forming ink using the carbon nanowire dispersion liquid of the present invention can not only be printed on a substrate as described above, but can also be filled in through holes and via holes, so that it can be applied to various multilayer wiring boards It is.
  • the method for producing a carbon nanowire dispersion liquid of the present invention uses carbon fiber, sized carbon fiber, or CFRP as a raw material, and first performs "dry grinding” or “dry grinding” as a raw material Although “used", wastes and unnecessary things can also be used as the CFRP. Alternatively, commercially available CFRP products can be used, and optionally after coarse grinding, dry grinding (used as a raw material). By grinding and dispersion treatment under the specific conditions of the present invention, plastics other than the carbon fiber itself are substantially removed from the obtained dispersion, and they are substantially the same regardless of the starting materials.
  • the dispersion stability of the carbon nanowire dispersion liquid of the present invention can be further enhanced by using a water-soluble polymer as a dispersion medium, and can be suitably used as, for example, various water-based paint for conductor formation. It is.
  • the dispersion medium is “2-pyrrolidone in which the nitrogen atom may be substituted with a hydrocarbon group”, and further contains polyimide in the dispersion stability.
  • it can be suitably used as various organic solvent paints and inks for forming conductive circuits.
  • the present invention is a carbon nanowire dispersion liquid characterized in that a carbon nanowire having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 to 200 is dispersed in a dispersion medium. .
  • the average fiber diameter, average fiber length, average aspect ratio and particle size distribution of carbon fibers and carbon nanowires are measured by the method described in the Examples, and defined as such measurements.
  • carbon nanowire has a chemical structure of graphite (graphite) and a chemical structure of carbon fiber, and has an average fiber diameter of 300 nm or less and an average aspect ratio of 30 or more.
  • the average fiber length is short and the average fiber diameter is also thin.
  • the average fiber length and the average fiber diameter are smaller.
  • a carbonaceous material such as graphite
  • a plastic derived from CFRP etc.
  • the average fiber diameter of the carbon nanowires is 300 nm or less, preferably 200 nm or less, more preferably 130 nm or less, still more preferably 100 nm or less, and particularly preferably 80 nm or less. If the upper limit is less than or equal to the above, dispersibility and dispersion stability are improved, and the “structure such as a coating film or circuit” obtained by applying and printing the obtained dispersion (paint or ink having the same) Conductivity, thermal conductivity, heat dissipation, rust prevention, jet blackness, uniformity, etc. are improved. In addition, the effects of the present invention described above can be achieved.
  • the lower limit of the average fiber diameter of carbon nanowires is not particularly limited, but is preferably 20 nm or more, particularly preferably 30 nm or more, from the viewpoint of easiness of production including pulverization, dispersion and the like.
  • the average fiber length of carbon nanowire 60 micrometers or less are preferable, as for the average fiber length of carbon nanowire, 40 micrometers or less are more preferable, 25 micrometers or less are still more preferable, and 15 micrometers or less are especially preferable. If the upper limit is less than or equal to the above, dispersibility and dispersion stability are improved, and the above-described effects of the present invention are exhibited. On the other hand, the lower limit of the average fiber length of the carbon nanowire is preferably 1 ⁇ m or more, more preferably 2 ⁇ m or more, still more preferably 3 ⁇ m or more, and particularly preferably 4 ⁇ m or more.
  • the lower limit is at least the above, when the obtained dispersion liquid (paint or ink having the same) is applied and printed, it hardly enters the minute depressions of the substrate and becomes isolated, and obtained by application and printing Conductivity, thermal conductivity, heat dissipation, rust resistance, jet blackness, etc. of a structure such as a coating film or a circuit are improved. In addition, manufacturing including pulverization, dispersion and the like is facilitated, and the above-described effects of the present invention can be achieved.
  • the average aspect ratio of the carbon nanowires is 30 or more and 200 or less, preferably 40 or more and 180 or less, more preferably 50 or more and 170 or less, and particularly preferably 60 or more and 150 or less.
  • the above-mentioned “effect similar to the effect that the upper limit of the average fiber diameter is below or above and the effect that the lower limit of the average fiber length is above” is exhibited.
  • the upper limit of the average aspect ratio of the carbon nanowires is equal to or less than the above, the above-mentioned "effect similar to the effect that the lower limit of the average fiber diameter is more than the above or the effect that the upper limit of the average fiber length is the following" is exhibited.
  • the particle size distribution measured by the method described in the examples is, for example, as shown in FIG. 3, in which 95% is distributed in the range of less than two digits in particle diameter (horizontal axis), for example, FIG. As shown in 4, when the particle diameter (horizontal axis) is 95% distributed in the range of 2 digits or more, the average fiber length is maintained longer and the average aspect ratio becomes larger. So preferred. Excessive wet grinding may reduce the average fiber length too much and may reduce the average aspect ratio.
  • the dispersion medium of the carbon nanowire dispersion liquid of the present invention is used as a solvent or dispersion medium for paints, inks, etc., or as a solvent or dispersion medium for masterbatches when producing paints, inks, etc.
  • the thing is mentioned. Specific examples include, but are not limited to, the following.
  • ethylene glycol ethylene glycol condensates such as diethylene glycol and triethylene glycol; diacetates thereof; ethylene glycol monoalkyl (or phenyl) ethers such as ethylene glycol monoethyl ether and ethylene glycol monophenyl ether; monoacetates thereof Ethylene glycol dialkyl (or diphenyl) ethers such as ethylene glycol diethyl ether, ethylene glycol diphenyl ether; solvents obtained by replacing the above "ethylene glycol” with "diethylene glycol” or "triethylene glycol”;"propyleneglycol” above And the like.
  • alcohols such as 3,5,5-trimethylhexanol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol; carboxylic acid esters thereof; cyclic esters such as ⁇ -butyl lactone Carbonates such as propylene carbonate, butylene carbonate, vinyl carbonate, etc .; "pyrrolidones whose nitrogen atoms may be substituted by hydrocarbon groups” such as pyrrolidone, N-methyl pyrrolidone (NMP), N-ethyl pyrrolidone etc. (“pyrrolidone” And “2-pyrrolidone” is preferable); and the like.
  • acetic acid tetrahydrofuran
  • hydrocarbons such as benzene, cyclohexane and xylene
  • esters such as methyl acetate, ethyl acetate, dioctyl phthalate and aromatic esters
  • ketones such as acetophenone, methyl ethyl ketone (MEK), cyclohexanone and acetone
  • carbon tetrachloride Chlorine-containing solvents such as chloroform, trichloroethylene and dichloromethane
  • alcohols such as octylene glycol, acetone alcohol and isopropyl alcohol
  • carbon disulfide nitrogen-containing solvents such as pyridine, nitroethane and acetonitrile
  • dioxane ⁇ -caprolactone, ⁇ -butyrolactone ( And lactones such as GBL).
  • the dispersion media may be used alone or in combination of two or more.
  • carbon nanowire dispersions have a wide range of uses such as paints and inks, etc., that they have good crushability and dispersibility, that a specific surfactant suitably functions, and that their dispersion stability is good, Water is preferred from the viewpoint of safe and easy handling.
  • the water is more preferably pure water such as demineralized water or distilled water.
  • the particularly suitable use of the carbon nanowire dispersion liquid of the present invention is a conductive paint or a conductive ink, so that it is matched to a polymer substrate such as polyimide or polyepoxy as the substrate; bead mill treatment
  • a polymer substrate such as polyimide or polyepoxy as the substrate
  • bead mill treatment The compatibility with the pulverization by carbon dioxide is good; the dispersibility of carbon nanowires is particularly suitable; a specific surfactant functions suitably; and so on, such as pyrrolidone, N-methyl pyrrolidone, N-ethyl pyrrolidone etc.
  • ketone such as methyl ethyl ketone (MEK): lactone such as ⁇ -butyrolactone (GBL); etc. are preferable, and “nitrogen atom is substituted with a hydrocarbon group
  • 2-pyrrolidone "methyl ethyl ketone (MEK), ⁇ -butyrolactone (GBL), etc.
  • NMP methyl-2-pyrrolidone
  • the content ratio of the carbon nanowires dispersed in the carbon nanowire dispersion liquid of the present invention is not particularly limited, but preferably 0.01% by mass or more and 20% by mass or less with respect to the whole carbon nanowire dispersion liquid. 0.1 mass% or more and 15 mass% or less are more preferable, 0.3 mass% or more and 10 mass% or less are more preferable, and 1 mass% or more and 6 mass% or less are particularly preferable.
  • the dispersion liquid When the content ratio is at least the above lower limit, the dispersion liquid is not too thin and the dispersion medium is not wasted; the volume of the dispersion liquid is not increased more than necessary; the dispersion liquid is excessive when used in the production of paints, inks, etc. Since the dispersion medium of (1) is not contained, the use is expanded; On the other hand, the dispersibility and the dispersion stability of the carbon nanowires are improved when the content ratio is not more than the above upper limit; the dispersibility is improved without the viscosity and the concentration of the dispersion becoming too high at the time of grinding such as bead milling And the dispersion time is shortened; carbon nanowires with a large aspect ratio can be obtained; and so on.
  • the “method for producing a carbon nanowire dispersion” of the present invention is a method for producing the “carbon nanowire dispersion described above”, and A method of dry-pulverizing carbon fibers or preparing dry-pulverized carbon fibers and thereafter dispersing the carbon fibers in the dispersion medium while grinding the carbon fibers by wet-pulverizing in the dispersion medium, In the wet grinding, the dry ground carbon fiber is contained in the dispersion medium, and the carbon fiber is subjected to bead milling in the presence of an anionic surfactant, whereby the carbon fiber has an average fiber diameter of 300 nm or less and an average It is characterized in that the aspect ratio is 30 or more and 200 or less.
  • Carbon fiber as raw material includes carbon fibers subjected to sizing treatment; carbon fiber reinforced plastics (hereinafter abbreviated as "CFRP"); carbon fiber reinforced carbon composite material 90% by mass or more according to the JIS standard is a carbonaceous material; carbon fiber alone or carbon material single; so-called carbon fibers; and the like.
  • CFRP carbon fiber reinforced plastics
  • the CFRP may be a prepreg obtained by causing carbon fiber to be contained in a matrix resin in a matrix resin, which is heated under pressure in an autoclave, or a molded by heating using a microwave or the like.
  • CFRP carbon fibers
  • “carbon fibers” such as CFRP are longitudinally unwound by bead milling in the presence of an anionic surfactant, and the average fiber length relative to the average fiber length It is particularly preferable to use CFRP as the above-mentioned "carbon fiber” as a raw material because the diameter can be specifically narrowed, in order to take advantage of the features of the present invention.
  • the present invention does not exclude the case where the substance remains or adheres to the carbon nanowires.
  • the above “transfer into the dispersion medium” may be, for example, when it is dissolved in the dispersion medium; when it is finely dispersed or lumped and dispersed; when it is suspended or separated in the dispersion medium;
  • carbon fiber is dry-ground or dry-ground carbon fiber is prepared. That is, carbon fibers may be dry-ground (renewed), or carbon fibers which have already been dry-ground may be obtained and used, but dry-grinding carbon fibers before bead mill processing described later Is preferred.
  • the "carbon fiber” which is a raw material before dry grinding may be a chopped fiber, a milled fiber, etc. crushed to some extent or the like, or it may be roughly crushed if a large CFRP etc. is required. In addition, it may be a waste material or CFRP (which is roughly crushed) which has become unnecessary.
  • CFRPs that are no longer needed include those that are no longer needed for commonly used and sold CFRPs, CFRPs that are wastes, and CFRPs that have come out as prototypes (including failed products) by manufacturers etc. Be Specifically, but not limited to, for example, golf club shafts; tennis racquet frame materials; fishing rods; car frames and various parts; plane wings and various parts; Parts; cases of musical instruments, portable items, etc .;
  • the “carbon fiber” as a raw material a pitch-based (PITCH-based) carbon obtained by carbonizing a pitch at a high temperature
  • PAN-based bread-based
  • PITCH-based pitch-based carbon obtained by carbonizing a pitch at a high temperature
  • it may be a fiber, it is preferably a pitch-based (PITCH-based) carbon fiber from the viewpoint of excellent conductivity and the ease with which a carbon nanowire with a large aspect ratio can be obtained.
  • dry grinding is first performed, and as the dry grinding, pneumatic grinding using "air flow grinding machine such as cyclone mill; jet mill; etc.”;”crusher mill, pin mill, cutter mill, hammer” Mills, axial flow mills, etc. “rotational impact grinding, roll grinding, medium grinding, stone grinding, cutter grinding” and the like can be mentioned.
  • pneumatic pulverization using a cyclone mill, jet mill or the like is particularly preferable as the dry pulverization in the present invention.
  • an air flow is generated by rotation of an impeller (rotor blade), and an object placed in the air flow is dryly crushed to produce fine particles.
  • the target is made to collide with the collision plate, and the target is dry ground to produce fine particles.
  • An apparatus marketed can also be used conveniently as a cyclone mill.
  • Cyclone mill manufactured by Shizuoka Plant Co., Ltd. Cyclone mill manufactured by Shizuoka Machine Co., Ltd., super powder mill manufactured by Nishimura Machinery Co., Ltd., tornado mill manufactured by Mitaka Industry Co., Ltd., Furukawa Sangyo Co., Ltd.
  • a Dream Mill manufactured by Systems Co., Ltd. may, for example, be mentioned.
  • the structure of the above-mentioned cyclone mill is not particularly limited, but it has one or more impellers, and it is mainly intended that the objects to be crushed are collided and crushed by the swirling air flow generated by the impellers. It is particularly preferable from the viewpoint of easily achieving the effects by using the air flow crusher; very little metal contamination; and the like.
  • the impellers may be rotated in the same direction or in opposite directions, respectively.
  • the air flow crusher has a classification function inside, and the classified coarse powder can be crushed again inside and the classified fine powder can be taken out. Particularly preferred in view of obtaining a narrow distribution for removing coarse powder.
  • the classification function is not particularly limited, but is preferably a cyclone classification function from the viewpoint of high classification ability.
  • the ambient temperature or setting temperature in the case of using a cyclone mill is not particularly limited and may be in accordance with the use of the apparatus used, but is preferably 0 ° C. to 50 ° C., particularly preferably 5 ° C. to 35 ° C. .
  • the impeller rotational speed in the case of using a cyclone mill may be in accordance with the method of use of the apparatus used, but is preferably 4000 rpm or more and 20000 rpm or less, and particularly preferably 8000 rpm or more and 15000 rpm or less.
  • a commercially available apparatus can also be suitably used as a jet mill.
  • Examples of commercially available manufacturers include Seishin Enterprise Co., Ltd., Hosokawa Micron Corporation, Nippon Pneumatic Mfg Co., Ltd., Nisshin Engineering Co., Ltd., and the like.
  • the ambient temperature or setting temperature in the case of using a jet mill is not particularly limited and may be in accordance with the method of use of the apparatus used, but is preferably 0 ° C. or more and 50 ° C. or less, particularly preferably 5 ° C. or more and 35 ° C. or less .
  • the jet injection pressure or injection speed may be in accordance with the method of use of the apparatus used, but most preferably, compressed air at 20 ° C. and 6 bar (0.6 MPaG) is used as a grinding gas, and a 500 m / s nozzle The spouting speed is most preferred.
  • the preferred range is ⁇ 20% of the above value, and particularly preferred is ⁇ 10% of the above value.
  • carbon fiber which is a raw material in the present invention
  • dry grinding By carrying out dry grinding until the average fiber length becomes 70 ⁇ m or less and then carrying out wet grinding, the required range of the average fiber diameter, average fiber length, shape distribution, etc. of carbon nanowires in the carbon nanowire dispersion liquid or It becomes easy to be included in the suitable range.
  • the average fiber length is preferably 70 ⁇ m or less by dry grinding, more preferably 5 ⁇ m to 60 ⁇ m, still more preferably 10 ⁇ m to 50 ⁇ m, and particularly preferably 15 ⁇ m to 40 ⁇ m.
  • the upper limit is larger than the above, even if the average fiber diameter of the carbon nanowires hardly reaches 300 nm or less finally even if the conditions of the wet grinding are adjusted by wet grinding using a bead mill which is the next step, or In some cases, the average fiber diameter of the above-described (more preferable or particularly preferable) carbon nanowires is difficult to be achieved.
  • the average fiber length and average aspect ratio of the carbon nanowires may hardly fall in the above-mentioned ("more preferable" or "particularly preferable") range. .
  • the average fiber length of the carbon nanowires can not exceed the lower limit after wet grinding, so finally the average fiber length and average aspect ratio of the carbon nanowires are described above (" There is a case where it is difficult to be in the range of “preferred” or “particularly preferred”. In particular, the average aspect ratio of the final carbon nanowire may be too small.
  • the average fiber diameter after dry grinding is preferably 3000 nm or more, and particularly preferably 5000 nm or more and 15000 nm or less.
  • the average aspect ratio after dry pulverization is not particularly limited, but is preferably 10 or less, more preferably 7 or less, and particularly preferably 0.5 or more and 5 or less.
  • the present invention can be finally achieved by dry-grinding, even with a relatively large average fiber diameter or relatively small average aspect ratio, or by specific wet-grinding later on. It has been found that suitable "small average fiber diameter and large average aspect ratio" can be obtained.
  • the average fiber diameter of "the above-mentioned dry-ground carbon fiber" before wet grinding is 3000 nm or more and the average aspect ratio is 10 or less preferable.
  • Wet grinding is carried out after dry grinding, wherein the wet grinding contains the dry ground carbon fiber in the dispersion medium and is subjected to bead milling by bead milling in the presence of an anionic surfactant.
  • the shape (average fiber diameter, average fiber length, average aspect ratio) and particle size distribution of carbon nanowires are used. That is, finally, carbon fibers are formed into carbon nanowires having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 or more and 200 or less, and the above-described ⁇ carbon nanowire dispersion> ⁇ carbon nanowires >> Particularly preferred is the formation of carbon nanowires in a range of shapes and particle size distributions. It goes without saying that another process may be interposed between dry grinding and wet grinding. Examples of the "other processing" include pre-mixing, pre-mixing, and the like.
  • bead milling is performed using a bead mill.
  • carbon nanowires of the specific shape and particle size distribution as described above and a carbon nanowire dispersion liquid are obtained for the first time.
  • the conditions for bead milling are adjusted so as to obtain the above-mentioned specific mean fiber diameter, mean fiber length, mean aspect ratio, and particle size distribution of carbon nanowire and carbon nanowire dispersion liquid.
  • the conditions for bead milling described below are extremely important in order to obtain carbon nanowires of the above-described shape by finally pulverizing carbon fibers after dry pulverization, and the combination of the respective conditions in bead milling can be easily selected. It is not a natural range.
  • Examples of the material of the beads used in the bead mill include glass, alumina, zircon (zirconia-silica ceramic), zirconia, metal (steel) and the like, with zirconia and the like being preferable and zirconia being particularly preferable from the viewpoint of hardness and the like.
  • the bead diameter of the beads used in the bead mill is preferably 0.1 mm or more and 1.5 mm or less, more preferably 0.3 mm or more and 1 mm or less, and particularly preferably 0.5 mm or more and 0.8 mm or less. If the bead diameter is too large, the number of beads in the bead mill container will decrease and the contact point will decrease, and if it can not be suitably dispersed, the average fiber diameter etc. may not be reduced sufficiently. On the other hand, when the bead diameter is too small, when it can not be suitably dispersed, pulverization may take too long.
  • bead packing factor used for a bead mill 45% or more and 85% or less are preferable, 55% or more and 80% or less are more preferable, and 65% or more and 75% or less are particularly preferable.
  • the bead filling rate is too small, it is difficult for the carbon fiber to be vertically cracked, and it may be difficult to produce a carbon nanowire with a large aspect ratio.
  • the stirring blade of the bead mill may not be easily rotated.
  • the shape of the stirring blade used in the bead mill processing is a propeller type, and since the dispersion has extremely high structural viscosity and thixotropy, the shear rate is increased (the viscosity is not increased), and the stirring property and the grinding property In order to keep the dispersibility properly.
  • the number of rotations of the stirring blade depends on the length of the stirring blade, it is preferably 500 rpm or more and 2000 rpm or less, more preferably 700 rpm or more and 1500 rpm or less, and particularly preferably 1000 rpm or more and 1200 rpm or less.
  • the peripheral speed of the tip of the agitating blade (agitator) depends on the length of the agitating blade, but is preferably in the range which can be calculated from the above-mentioned rotational speed as a diameter of 20 cm.
  • 5 m / s or more and 20 m / s or less are preferable, 7 m / s or more and 16 m / s or less are more preferable, and 9 m / s or more and 13 m / s or less are particularly preferable.
  • the operation mode of the grinding and dispersion of the bead mill may be either a circulation system or a batch system, but the circulation system is preferred.
  • the circulation type since it is not delivered to the container as in the batch type, reagglomeration does not proceed at that time.
  • the circulation method is used, the degree of miniaturization changes with the number of passes. For example, when the residence time per pass is increased to 60 minutes at 5000 mL, the particle size distribution becomes sharp due to the absence of the short path of the treated product, but the aspect ratio of the carbon nanowire itself also decreases. Therefore, for example, it is desirable that the circulation speed per pass is preferably 10 minutes to 40 minutes, particularly preferably 15 minutes to 30 minutes, preferably 2 passes or more, particularly preferably 3 passes or more.
  • the time per pass (continuous operation time), the number of passes, and the total time depend on the device structure, concentration, grinding dispersion conditions, type of carbon fiber (CFRP), type of anionic surfactant, etc. Since there are cases, the dispersion after wet-pulverization is appropriately adjusted by observing one by one with a particle size distribution measuring device, a scanning electron microscope (SEM) or the like.
  • SEM scanning electron microscope
  • the time per one pass is preferably 7 minutes to less than 45 minutes, more preferably 10 minutes to 40 minutes, and particularly preferably 15 minutes to 30 minutes.
  • the upper limit is set to the above or less, the average aspect ratio can be increased.
  • 20 minutes or more and 180 minutes or less are preferable, and, as for the total time of wet grinding and dispersion
  • the temperature of the dispersion and carbon fibers (carbon nanowires) in bead milling is preferably 0 ° C. or more and 50 ° C. or less, particularly preferably 5 ° C. or more and 35 ° C. or less.
  • the bead mill in the present invention is a wet bead mill, but may be vertical or horizontal. Moreover, a bead mill can also use a commercially available apparatus. As a commercially available apparatus, for example, a bead mill manufactured by Ashizawa Finetech Co., Ltd., a Dino Mill of Willie E. Bachkofen (WAB), a bead mill of Imex Co., Ltd., a bead mill of Netti (US) and the like can be mentioned.
  • a commercially available apparatus for example, a bead mill manufactured by Ashizawa Finetech Co., Ltd., a Dino Mill of Willie E. Bachkofen (WAB), a bead mill of Imex Co., Ltd., a bead mill of Netti (US) and the like can be mentioned.
  • the wet grinding is preferably performed by bead milling in the presence of an anionic surfactant to disperse simultaneously with the grinding.
  • the anionic surfactant is preferably a polymeric anionic surfactant ("polymer” also includes an oligomer), and an alkali metal salt of a (co) polymer having an acid group, More preferably, they are ammonium salts, alkyl ammonium salts, alkylol ammonium salts and the like.
  • the (co) polymer having an acid group is a (co) polymer of (meth) acrylic acid, a (co) polymer of (anhydride) phthalic acid, and a (co) polymer of vinyl benzene sulfonic acid And at least one (co) polymer selected from the group consisting of (co) condensates of naphthalenesulfonic acid is particularly preferable.
  • the descriptions “(co)”, “(meth)”, and “(anhydrous)” indicate that parentheses may or may not be included.
  • copolymerization monomer in the case of a copolymer, (meth) acrylic acid alkyl ester, (meth) acrylic acid hydroxyalkyl ester, styrene etc. are mentioned.
  • the (co) condensed product of naphthalenesulfonic acid includes one having a ring bonded by an aldehyde such as formaldehyde.
  • aldehyde such as formaldehyde.
  • co-condensation monomer in the case of co-condensate, phenol, cresol, naphthol and the like can be mentioned.
  • the counter cation of the (co) polymer having an acid group is more preferably an alkali metal salt, an ammonium salt, an alkyl ammonium salt or an alkylol ammonium salt, particularly preferably a sodium salt or an alkylol ammonium salt is there.
  • anionic surfactants may be used alone or in combination of two or more.
  • the carbon fiber can be longitudinally unwound to shorten the average fiber length. Without this, the average fiber diameter can be reduced, and carbon nanowires (dispersion liquid) having a large average aspect ratio can be obtained.
  • the amount of the anionic surfactant used is not particularly limited, but two or more anionic surfactants may be used with respect to 100 parts by mass of carbon fiber (the same applies to carbon nanowires) to be crushed and dispersed. When used in combination), preferably 10 to 200 parts by weight, more preferably 20 to 150 parts by weight, and particularly preferably 30 to 100 parts by weight is there. If the amount of the anionic surfactant used is too small, the effect of unraveling the carbon fiber is hardly exhibited, and it becomes difficult to narrow the average fiber diameter without shortening the average fiber length, and the average aspect ratio It may be difficult to obtain large carbon nanowires (dispersion liquid).
  • the carbon fibers may cause aggregation during melting in the longitudinal direction.
  • a dispersion liquid in a state in which the carbon nanowires are aggregated is obtained, and thus when applied to an object, the conductivity of the obtained material may be affected.
  • ⁇ dispersion medium >>>
  • the dispersion medium to be used and the preferable dispersion medium are as described above in the section of ⁇ dispersion medium >> in ⁇ carbon nanowire dispersion liquid>.
  • the content ratio of the carbon nanowires dispersed in the carbon nanowire dispersion liquid of the present invention is as described above, but in the production method, 2 parts by mass of dry pulverized carbon fiber in 100 parts by mass of dispersion medium is used. It is preferable to carry out wet grinding by containing it in an amount of 7 parts by mass or less. More preferably, it is 3 parts by mass or more and 6.5 parts by mass or less, and particularly preferably 4 parts by mass or more and 6 parts by mass or less. If the content ratio is too small, the viscosity of the dispersion may be too low and the efficiency of pulverization may decrease. On the other hand, if the content ratio is too large, the viscosity of the dispersion may be too high to make the stirring blade difficult to turn And the efficiency of grinding may decrease.
  • Carbon nanowire dispersion liquid is also a carbon nanowire dispersion characterized in that it is produced by the above-mentioned "Method of producing a carbon nanowire dispersion”.
  • the paint and the ink using the carbon nanowire dispersion liquid of the present invention can suitably impart conductivity, thermal conductivity, heat dissipation, rust resistance, jet blackness and the like to the surface of an object.
  • the present invention is also a paint or ink for imparting conductivity, heat conductivity, heat dissipation, rust resistance or jet-blackness to the surface of an object.
  • the carbon nanowire dispersion liquid of the present invention and a polymer dissolved therein, and the dispersion medium (solvent) being distilled off, "the carbon nanowire is encapsulated in the polymer", “coating film, circuit, structure Or “powder” is suitable as a functional thing with the said performance.
  • the method of printing the ink is not particularly limited, and examples thereof include inkjet printing, screen printing, electrophotographic printing, offset printing, relief printing, intaglio printing, gravure printing, tampo printing, handwriting printing, and the like.
  • the present invention is also a "paint or ink" characterized in that the dispersion medium of the carbon nanowire dispersion described above is water, and further contains at least a water-soluble polymer. Particularly preferably, the dispersion medium of the above-mentioned carbon nanowire dispersion liquid is water, and at least a water-soluble polymer is further contained therein. ".
  • water-soluble polymer those used for water-based paints and inks can be used, but polyvinyl alcohol, polyvinyl pyrrolidone, high molecular weight polyester, etc. have good adhesion by coating on film, paper, fiber, etc. It is preferable from the point of being able to adjust the hardness affecting the property.
  • the water-soluble polymer also includes a copolymer as long as the water solubility is maintained.
  • the dispersion medium of the carbon nanowire dispersion liquid of the present invention may be an organic solvent.
  • the organic solvent include those described above.
  • NMP N-methyl-2-pyrrolidone
  • GBL ⁇ -butyrolactone
  • MEK methyl ethyl ketone
  • a polymer is contained as a binder or a vehicle.
  • the polymer is not particularly limited, but polyimide, polyepoxy (precursor) and the like are mentioned as preferable. More preferably, they are aromatic polyimide, polyepoxy (precursor) and the like.
  • the polyimide those in a varnish state can be used.
  • the carbon nanowire dispersion can be blended on the main agent side or the curing agent side.
  • Aromatic polyimides have higher strength and higher heat resistance than ordinary polymers.
  • the coefficient of linear expansion is very low as an organic substance and close to metal, when forming an electronic circuit, distortion due to thermal expansion with metal (wiring) hardly occurs, and high-precision wiring processing is possible, In particular, aromatic polyimides are preferred.
  • the dispersion medium of the carbon nanowire dispersion described above is “2-pyrrolidone in which the nitrogen atom may be substituted with a hydrocarbon group”, and further contains at least a polyimide therein. It is also a "paint or ink” characterized by
  • the carbon nanowire dispersion liquid of the present invention is particularly preferably applied to a conductivity imparting material such as an ink for forming a conductive circuit, a conductive paint and the like.
  • paints or inks may further contain known compounding agents according to their use and "coating method or printing method".
  • the compounding agent for example, an antifoamer, a fluidity regulator, an organic or inorganic filler, a stabilizer, a dispersing (stabilizing) agent, a surfactant other than the above, a solvent other than the solvent of the dispersion, wettability
  • examples include modifiers, leveling agents, plasticizers, structural viscosity imparting agents, thixotropy imparting agents, and the like.
  • the present invention is a carbon nanowire dispersion, which is a “paint or ink” containing carbon nanowires in the dispersion, and a “coating film, circuit, structure or powder in which the carbon nanowire is contained. "
  • Measurement example 1 ⁇ Average fiber diameter, average fiber length, average aspect ratio, particle size distribution>
  • the average fiber diameter and the average fiber length in the present invention were measured using SEM (No. JSM 7000 series manufactured by Nippon Denshi Co., Ltd.).
  • the average aspect ratio was determined by dividing the average fiber length determined by the above method by the average fiber diameter.
  • the particle size distribution is defined as a wet type measurement using a laser diffraction / scattering type particle size distribution measuring apparatus Nanotrac manufactured by Nikkiso Co., Ltd. and measurement using the measuring apparatus (method).
  • Measurement example 2 ⁇ Viscosity of dispersion> Using a B-type viscometer BM type, no. The # 4 rotor was rotated at 6 rpm and the viscosity at its shear rate was measured. The temperature was 25 ° C.
  • Measurement example 3 ⁇ Surface Resistivity of Surface Treated Film> The volume resistivity ( ⁇ ⁇ cm) was measured according to JlS L6911.
  • Example 1 ⁇ Raw material> CFRP milled fiber (70 ⁇ m to 150 ⁇ m in length, 11000 nm in diameter) was used as “carbon fiber” as a raw material. This carbon fiber was pitch based (PITCH based).
  • Dry grinding was performed on 500 g of the raw material under the following conditions.
  • a cyclone mill which is the following air flow grinder, was used.
  • the obtained product has an average fiber diameter of 8000 nm (a distribution width of 90% by volume, 5000 nm to 11000 nm), an average fiber length of 45 ⁇ m (a distribution width of 90% by volume, 20 ⁇ m to 70 ⁇ m), and an average aspect ratio was 5.6.
  • the above obtained by wet grinding has an average fiber diameter of 200 nm (90 nm by volume distribution, 100 nm to 300 nm), an average fiber length of 15 ⁇ m (90 volume% of distribution width, 10 ⁇ m to 20 ⁇ m), average aspect The ratio was 75.
  • the scanning electron micrograph (SEM photograph) of the carbon fiber after dry-pulverization of Example 1 before wet-pulverization is shown in FIG. 1, and the carbon nanowire dispersed in the carbon nanowire dispersion liquid after wet-pulverization
  • the scanning electron micrograph (SEM photograph) is shown in FIG.
  • Example 1 In Example 1, ⁇ dry grinding> and ⁇ premixing> are the same, and in ⁇ wet grinding and dispersing treatment>, the bead milling time (one pass time and the number of passes) is as follows. Wet pulverization and dispersion treatment were carried out in the same manner as in Example 1.
  • the wet-pulverized product had an average fiber diameter of 200 nm, an average fiber length of 0.67 ⁇ m, and an average aspect ratio of 3.4.
  • the particle size distribution is shown in FIG.
  • Example 2 In Example 1 and Reference Example 1, ⁇ dry grinding> and ⁇ premixing> were the same, and in ⁇ wet grinding and dispersing treatment>, bead milling time (one pass time and number of passes) was as follows. The wet grinding and the dispersion treatment were performed in the same manner as in Example 1 and Reference Example 1 except for the above.
  • the wet-pulverized product had an average fiber diameter of 200 nm, an average fiber length of 15 ⁇ m, and an average aspect ratio of 75.
  • the particle size distribution is shown in FIG.
  • Example 1 In Example 1 in which the time of one pass is short, the particle size distribution was not sharper than in Reference Example 1 in which the time of one pass was long, but the average fiber length remained long and the average aspect ratio was as large as 75. On the other hand, in Reference Example 1 in which the time of one pass is long, the particle size distribution is sharp, but the average fiber length is short and the average aspect ratio is as small as 3.4.
  • Example 3 50 g of the aqueous carbon nanowire dispersion obtained in Example 1 (containing 2.5 g of carbon nanowire), 50 g of polyvinyl alcohol, and 20 g of polymethyl methacrylate (PMMA) (copolymer) are mixed by stirring, The obtained paint was applied on a general-purpose copy paper at 120 g / m 2 using a bar coater and dried.
  • PMMA polymethyl methacrylate
  • the conductive coating film obtained had an extremely low electrical resistance, and the surface of the paper maintained conductivity even when it was strongly folded 180 ° with the coated surface outward (even if completely folded). Since the average fiber length is long, it is considered that the conductive property is not interrupted because the portions where wires having long fibers intervene are more in contact with each other than the nanoparticles having short fiber lengths. In addition, since the average fiber length is long, the particles do not fall off by being entangled in the fibers of the paper, and even when the paper is bent, the voids are in contact with the carbon nanowires. It is thought that
  • Example 4 In Example 1, ⁇ dry pulverization> was identical, and ⁇ premixing> and ⁇ wet pulverization and dispersion treatment> were performed as follows.
  • NMP N-methyl-2-pyrrolidone
  • the average fiber diameter of the product obtained by the above wet pulverization is finally 200 nm (distribution width of 90% by volume, 100 nm to 300 nm), average fiber length is 10 ⁇ m (distribution width of 90% by volume, 5 ⁇ m to 15 ⁇ m)
  • the average aspect ratio was 50.
  • Example 5 In Example 4, the same amount of the anionic surfactant as in Example 4 was introduced into the bead mill container in the middle of the wet pulverization and dispersion treatment of Example 4 and stirred in the same manner as in Example 4.
  • the transition of the average fiber diameter, the average fiber length, and the viscosity in the bead mill wet grinding process (time transition) was as follows.
  • the bead conditions, the stirring conditions, and the like were the same as in Example 4, and the conditions were always fixed even if time went by. As for the following, as it goes down, time has passed. The description of "average" is omitted.
  • an anionic surfactant is added, and the chemical dispersion start fiber diameter 1000 nm, fiber length 10 ⁇ m, aspect ratio 10, viscosity 700 MPa ⁇ s Fiber diameter: 200 nm, fiber length: 10 ⁇ m, aspect ratio: 50, viscosity: 700 MPa ⁇ s Finish of bead mill wet grinding
  • Example 6 In Example 4 and Example 5, 100 parts by mass of ⁇ -butyrolactone (GBL) or 100 parts by mass of methyl ethyl ketone (MEK) instead of 100 parts by mass of N-methyl-2-pyrrolidone (NMP) as a dispersion medium
  • GBL ⁇ -butyrolactone
  • MEK methyl ethyl ketone
  • NMP N-methyl-2-pyrrolidone
  • Example 7 The carbon nanowire dispersion obtained in Example 4 was added to a polyimide (varnish type).
  • a polyimide varnish Ube Industries, Ltd. product Yupia (registered trademark) -AT (U-varnish-A) [for general heat resistance], and Yupia (registered trademark)-ST (U-varnish-S) [high heat resistance was used.
  • the carbon nanowire dispersion obtained in Example 4 was added to 100 parts by mass of each of the above-mentioned polyimide varnishes only in the following parts by mass. 5 parts by mass (0.25 parts by mass of carbon nanowires) 10 parts by mass (0.50 parts by mass of carbon nanowires) 20 parts by mass (1.0 parts by mass of carbon nanowires) 40 parts by mass (2.0 parts by mass of carbon nanowires) 50 parts by mass (2.5 parts by mass of carbon nanowires) 80 parts by mass (carbon nanowires 4.0 parts by mass)
  • a paint or an ink was obtained by using an automatic mixer AS100 manufactured by As One Co., Ltd. as a machine for mixing the above, and repeating this twice with a stirring time of 14 seconds.
  • the resulting paint or ink was coated on a 20 ⁇ m polyimide resin film.
  • the coater was coated at 12 ⁇ m using a bar coater. After coating, the film was baked by heating at 140 ° C. for 5 minutes in an oven to obtain a surface-treated film.
  • Each of the surface-treated films obtained by coating the polyimide resin film with the paint or ink obtained above and heating and baking it has a volume resistivity of 1.0 ⁇ 10 ⁇ 8 measured by the evaluation method 3 It was less than [ ⁇ ⁇ cm].
  • the paint or ink obtained above was able to impart conductivity, thermal conductivity, heat dissipation and jet blackness to the surface of the polyimide resin film as the object. If the object is a metal, it is considered to provide corrosion resistance.
  • Example 8 A paint or an ink was prepared in the same manner as in Example 7 using an epoxy resin and an acrylic resin instead of the polyimide of Example 7, to obtain a surface-treated film.
  • a dispersion medium NMP was used for all.
  • a conductive film, a heat conductive film, a heat dissipating film, an anticorrosive film, and a jet-black film were obtained.
  • the epoxy resin containing a curing agent the cured epoxy resin cured product formed a micro phase separation structure.
  • Example 9 The “paint or ink” obtained in Example 7 and Example 8 is placed in a glass bottle and heated in an oven at 120 ° C. for 1 hour to 1 hour and 20 minutes to evaporate the dispersion medium, and the dried product and Got a powder.
  • the powder was nano-sized powder. Although all were agglomerated, it was possible to be easily diffused in water, an acrylic monomer, and an epoxy resin main agent. The following was considered as the reason. That is, the anionic surfactant (for example, an alkylol ammonium salt of a copolymer containing an acid group) used in the wet grinding / dispersion step is attached to the surface of the carbon nanowire, and volatilizes even at a drying temperature of 120 ° C. It is considered that the dispersion is very good in the dispersion medium, the monomer, the binder, etc.
  • the anionic surfactant for example, an alkylol ammonium salt of a copolymer containing an acid group
  • the amount to be attached can be adjusted and changed depending on the amount and type of anionic surfactant added at the time of viscosity adjustment of bead mill wet grinding and dispersion, so application is possible depending on the amount and type of anionic surfactant The range spreads.
  • the carbon nanowire dispersion liquid of the present invention, and the paint or ink using the dispersion liquid contain carbon nanowires having a specific shape, and therefore, the surface has conductivity, heat conductivity, heat dissipation, prevention It can be made to have rustiness, jet-blackness, etc. Therefore, since "a film, a structure, etc.” having “a film, a layer, etc.” having the performance, and “powder, a circuit, a structure, etc.”, having the performance, such performance is required. It is widely used in various fields (required).

Abstract

The present invention addresses the problem of providing: a carbon nanowire dispersion liquid in which carbon nanofibers having an average fiber diameter in the nano-size range have a long average fiber length compared to the narrowness of said average fiber diameter, are easy to grind and disperse within a dispersion medium, and are unlikely to reagglomerate; and a method for producing the carbon nanowire dispersion liquid. The problem is solved by a carbon nanowire dispersion liquid in which carbon nanowires having an average fiber diameter of 300 nm or less and an average aspect ratio of 30-200 are dispersed within a dispersion medium, and by a method for producing the carbon nanowire dispersion liquid in which carbon fibers are subjected to dry grinding or dry-ground carbon fibers are prepared, then said carbon fibers are ground while being dispersed in a dispersion medium by performing wet grinding within the dispersion medium. When performing the wet grinding, the dry-ground carbon fibers are incorporated into the dispersion medium, bead mill processing is performed in the presence of an anionic surfactant, and the carbon fibers thereby become carbon fibers having an average fiber diameter of 300 nm or less and an average aspect ratio of 30-200.

Description

カーボンナノワイヤー分散液及びその製造方法Carbon nanowire dispersion liquid and method for producing the same
　本発明は、特定の形状を有するカーボンナノワイヤーが分散された分散液、その製造方法、及び、該分散液から得られる塗料若しくはインクに関するものである。 The present invention relates to a dispersion in which carbon nanowires having a specific shape are dispersed, a method for producing the same, and a paint or ink obtained from the dispersion.
　従来、炭素繊維、サイジング処理された炭素繊維、炭素繊維強化プラスチック（ＣＦＲＰ）（carbon fiber reinforced plastics）は、軽量であり、強靭さとしなやかさを合わせ持っているため、金属の代替として種々の成形品に多く利用されており、更にその廃ＣＦＲＰも利用されている（例えば、特許文献１～４）。
　中でも最も短い炭素繊維は、ミルドファイバーとも言われ、一般には平均繊維長は７０μｍ以上２００μｍ以下であり、平均繊維径は約１０μｍであり、そのサイズの細かさから、研磨剤、補強補助剤等に利用されていることが多い。 In the past, carbon fibers, sized carbon fibers and carbon fiber reinforced plastics (CFRPs) are lightweight and have a combination of toughness and flexibility, so various molded articles can be used as substitutes for metals. And waste CFRP is also used (for example, Patent Documents 1 to 4).
Among them, the shortest carbon fiber is also referred to as milled fiber, and in general, the average fiber length is 70 μm or more and 200 μm or less, and the average fiber diameter is about 10 μm. It is often used.
　ミルドファイバーより長い平均繊維長を持つチョップドファイバーやラインＣＦＲＰは、プリプレグ、フォージド等の成型品に用いられることが主流である。
　また、これ以外のサイズとして、ミルドファイバーを更に粉砕し、繊維長を短くした微粒ＣＦＲＰは、例えばコンクリートの補強材等に利用されている。 It is the mainstream that chopped fiber and line CFRP having average fiber length longer than milled fiber are used for molded articles such as prepreg and forged.
Moreover, as a size other than this, milled fiber is further grind | pulverized and fine particle CFRP which shortened fiber length is utilized for the reinforcing material etc. of a concrete, for example.
　しかし、ＣＦＲＰや所謂「炭素繊維」は、短くなるほど加工性が難しくなり、凝集し易くなることから利用価値は少ないと考えられており、炭素繊維の繊維径やアスペクト比が記載された文献はあるが（例えば、特許文献５、６）、現在のところ、ミルドファイバーより細いサイズを有するナノサイズの炭素繊維は現実にはない。
　すなわち、現在、ナノサイズの炭素繊維の需要や利用度は極めて低く、特にアスペクト比が大きいナノサイズの炭素繊維は市場には（商業的には）存在せず、少なくともかかる炭素繊維が安定して分散している分散液は知られていない。 However, CFRP and so-called "carbon fibers" are considered to be less useful because their processability becomes more difficult and they tend to aggregate as they become shorter, and there are documents in which the fiber diameter and aspect ratio of carbon fibers are described. However, at present, nano-sized carbon fibers having a smaller size than milled fibers are not in reality.
That is, at present, the demand and utilization of nano-sized carbon fibers are extremely low, particularly nano-sized carbon fibers having a large aspect ratio are not (commercially) present in the market, and at least such carbon fibers are stable. There are no known dispersions in dispersion.
　その背景として、導電性においては、カーボンナノチューブ、銀、銅等のナノ粒子が市場に出ていて一般的であるため、ナノサイズの炭素繊維は不要である等の理由で存在していなかったと考えられる。
　また、ナノサイズの炭素繊維は、導電性等を必要とする種々のアプリケーションに利用が可能であると考えられるところ、分散液においては、平均繊維径が小さく、極めてアスペクト比が大きい炭素繊維の分散液は知られていなかった。 As the background, it is considered that nano-sized carbon fibers were not present for conductivity because nanoparticles such as carbon nanotubes, silver, copper, etc. are on the market and are generally available. Be
In addition, although it is considered that nano-sized carbon fibers can be used for various applications requiring conductivity etc., dispersions of carbon fibers having a small average fiber diameter and an extremely large aspect ratio The fluid was unknown.
特開平７－１１８４４０号公報JP 7-118440 A 特開２０００－２５４９１９号公報Japanese Patent Laid-Open No. 2000-254919 特開２００１－０３０２４５号公報JP 2001-030245 A 特開２００９－１３８１４３号公報JP, 2009-138143, A 特開２０１２－１８８７９０号公報JP 2012-188790 A 特開２０１７－０６６５４６号公報Unexamined-Japanese-Patent No. 2017-066546
　本発明は上記背景技術に鑑みてなされたものであり、その課題は、平均繊維径がナノサイズのカーボン繊維において、該平均繊維径の細さに比較して平均繊維長が長く、すなわちアスペクト比が大きく、分散媒体の中で粉砕及び分散がし易く、また再凝集がし難いカーボンナノワイヤー分散液、及び、その製造方法を提供することである。 The present invention has been made in view of the above background art, and the problem is that, in carbon fibers having an average fiber diameter of nanosize, the average fiber length is longer as compared to the fineness of the average fiber diameter, that is, the aspect ratio It is an object of the present invention to provide a carbon nanowire dispersion liquid which is easy to be easily crushed and dispersed in the dispersion medium and hardly reaggregated, and a method for producing the same.
　本発明者は、上記の課題を解決すべく鋭意検討を重ねた結果、サイジング処理された炭素繊維、炭素繊維強化プラスチック（carbon fiber reinforced plastics）（以下、「ＣＦＲＰ」と略記する）等の所謂「炭素繊維」の粉砕方法と分散方法とを特定のものとすれば、上記課題を解決できることを見出した。
　特に粉砕方法については、特定の２段階で粉砕すること、特定の界面活性剤の存在下で特定の方法で粉砕すること、特に分散方法については、特定の方法によってカーボンナノワイヤー表面に特定の界面活性剤を均一に付与することで、上記課題を解決し、優れたナノサイズのカーボンナノワイヤー分散液を製造できることを見出して本発明を完成するに至った。 As a result of intensive studies to solve the above-mentioned problems, the inventor of the present invention has identified so-called “carbon fiber reinforced plastic (carbon fiber reinforced plastics) (hereinafter abbreviated as“ CFRP ”) etc. It has been found that the above-mentioned problems can be solved if the method of pulverizing and dispersing the carbon fiber is specified.
In particular, for the grinding method, grinding in two specific steps, grinding in a specific method in the presence of a specific surfactant, and in particular for a dispersion method, an interface specific to the surface of the carbon nanowire by a specific method By uniformly applying the activator, the above problems are solved, and it is found that an excellent nano-sized carbon nanowire dispersion can be produced, and the present invention has been completed.
　すなわち、本発明は、分散媒中に平均繊維径が３００ｎｍ以下であり、かつ、平均アスペクト比が３０以上２００以下のカーボンナノワイヤーが分散されたものであることを特徴とするカーボンナノワイヤー分散液を提供するものである。 That is, the present invention is a carbon nanowire dispersion liquid characterized in that a carbon nanowire having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 to 200 is dispersed in a dispersion medium. To provide
　また、本発明は、上記のカーボンナノワイヤー分散液の製造方法であって、
　炭素繊維を乾式粉砕し、又は、乾式粉砕された炭素繊維を用意し、その後、分散媒中で湿式粉砕することによって、該炭素繊維を粉砕しつつ該分散媒に分散させるカーボンナノワイヤー分散液の製造方法であって、
　該湿式粉砕は、該分散媒の中に、該乾式粉砕した炭素繊維を含有させ、陰イオン系界面活性剤の存在下でビーズミル処理することによって、該炭素繊維を平均繊維径３００ｎｍ以下、かつ平均アスペクト比３０以上２００以下にすることを特徴とするカーボンナノワイヤー分散液の製造方法を提供するものである。 The present invention is also a method for producing the above-mentioned carbon nanowire dispersion liquid,
A carbon nanowire dispersion liquid in which carbon fibers are dispersed in the dispersion medium by pulverizing the carbon fibers in a dry state or preparing a dry-ground carbon fiber and then grinding the carbon fibers in the dispersion medium by wet grinding. A manufacturing method,
In the wet grinding, the dry ground carbon fiber is contained in the dispersion medium, and the carbon fiber is subjected to bead milling in the presence of an anionic surfactant, whereby the carbon fiber has an average fiber diameter of 300 nm or less and an average The present invention provides a method for producing a carbon nanowire dispersion liquid, which has an aspect ratio of 30 or more and 200 or less.
　また、本発明は、上記陰イオン系界面活性剤が、酸基を有する（共）重合物の、アルカリ金属塩又はアルキロールアンモニウム塩である上記のカーボンナノワイヤー分散液の製造方法を提供するものである。 In addition, the present invention provides a method for producing the above-mentioned carbon nanowire dispersion liquid, wherein the above-mentioned anionic surfactant is an alkali metal salt or alkylol ammonium salt of a (co) polymer having an acid group. It is.
　また、本発明は、上記分散媒が、水、又は、「窒素原子が炭化水素基で置換されていてもよい２－ピロリドン」である上記のカーボンナノワイヤー分散液の製造方法を提供するものである。 Further, the present invention provides a method for producing a carbon nanowire dispersion as described above, wherein the dispersion medium is water or "2-pyrrolidone in which the nitrogen atom may be substituted with a hydrocarbon group". is there.
　また、本発明は、上記カーボンナノワイヤー分散液の製造方法で製造されるようなものであることを特徴とするカーボンナノワイヤー分散液を提供するものである。 The present invention also provides a carbon nanowire dispersion liquid, which is characterized by being manufactured by the above method of manufacturing a carbon nanowire dispersion liquid.
　また、本発明は、上記のカーボンナノワイヤー分散液の分散媒が水であり、そこに更に少なくとも水溶性高分子を含有してなるものであることを特徴とする塗料若しくはインクを提供するものである。 Further, the present invention provides a paint or ink characterized in that the dispersion medium of the carbon nanowire dispersion described above is water, and further containing at least a water-soluble polymer therein. is there.
　また、本発明は、上記のカーボンナノワイヤー分散液の分散媒が「窒素原子が炭化水素基で置換されていてもよい２－ピロリドン」であり、そこに更に少なくともポリイミドを含有してなるものであることを特徴とする塗料若しくはインクを提供するものである。 Further, according to the present invention, the dispersion medium of the above-mentioned carbon nanowire dispersion liquid is “2-pyrrolidone in which a nitrogen atom may be substituted with a hydrocarbon group”, and at least polyimide is further contained therein. It provides a paint or ink characterized by a certain thing.
　本発明によれば、前記問題点や上記課題を解決し、平均繊維径が３００ｎｍ以下と十分に小さく、かつ、平均アスペクト比が極めて大きい炭素繊維（カーボンナノワイヤー）の分散液を得ることが可能である。分散媒中に平均繊維径が３００ｎｍ以下であり、かつ、平均アスペクト比が３０以上２００以下のカーボンナノワイヤーが分散されたカーボンナノワイヤー分散液は、今までに知られておらず、新規なものである。
　本発明のカーボンナノワイヤー分散液の製造方法によれば、平均アスペクト比が大きい特定のナノサイズの形状に好適に粉砕ができ、更に好適に分散媒中に分散することが可能で、そうして得られた分散液は、極めて分散安定性にも優れている。 According to the present invention, it is possible to solve the above problems and the above problems, and to obtain a dispersion of carbon fibers (carbon nanowires) having a sufficiently small average fiber diameter of 300 nm or less and an extremely large average aspect ratio. It is. A carbon nanowire dispersion liquid in which carbon nanowires having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 or more and 200 or less are dispersed in a dispersion medium has not been known so far and is novel It is.
According to the method for producing a carbon nanowire dispersion liquid of the present invention, it is possible to preferably grind to a specific nano-sized shape having a large average aspect ratio, and more preferably to disperse it in a dispersion medium, The obtained dispersion is also extremely excellent in dispersion stability.
　本発明のカーボンナノワイヤー分散液において分散されているカーボンナノワイヤーは、形状的には、所謂カーボンナノファイバー（ＣＮＦ）より、所謂銀ナノワイヤーやカーボンナノチューブに近い。従って、本発明におけるカーボンナノワイヤーは、化学構造的にはグラファイトであるが、形状的には銀ナノワイヤーに近いため、現在、銀ナノワイヤーが使用されている用途と同様の用途に好適に利用される。しかも、本発明のカーボンナノワイヤー分散液中のカーボンナノワイヤーは、価格的に銀ナノワイヤー（１５万円／ｇ）より極めて安価である（安価に製造できる）。 The carbon nanowires dispersed in the carbon nanowire dispersion liquid of the present invention are closer in shape to so-called silver nanowires and carbon nanotubes than so-called carbon nanofibers (CNF). Therefore, the carbon nanowires in the present invention are chemically structurally graphite, but are close to silver nanowires in shape, so they are suitably used in applications similar to those where silver nanowires are currently used. Be done. Moreover, the carbon nanowires in the carbon nanowire dispersion liquid of the present invention are extremely inexpensive (can be manufactured inexpensively) than silver nanowires (150,000 yen / g).
　本発明におけるカーボンナノワイヤーは、光散乱しない程度に平均径が小さく、低い電気抵抗率を有するため、透明導電膜等に対する用途が期待される。
　また、分散液であるため、蒸着、ＣＶＤ等による用途（分野）ではなく、分散液として塗布し、膜、層、配線等を形成する用途（分野）用途に好適に利用できる。すなわち、例えば、導電性、熱伝導性、放熱性、防錆性、漆黒性の「各種塗料や各種印刷インク等」として好適に利用できる。 Since the carbon nanowire in the present invention has a small average diameter to the extent that light does not scatter and has a low electrical resistivity, it is expected to be used for transparent conductive films and the like.
Further, since it is a dispersion, it can be suitably used not only for applications (fields) by vapor deposition, CVD, etc., but for applications (fields) where it is applied as a dispersion to form films, layers, wires, etc. That is, it can be suitably used as, for example, “various paints, various printing inks, etc.” of conductivity, heat conductivity, heat dissipation, rust prevention, jet blackness.
　また、分散体が粒子状ではなくワイヤー状であるため、すなわち、平均繊維径がナノサイズであると共にアスペクト比が大きいので、マイクロサイズの空隙を有する基板（紙；ポリイミドフィルム等の基板；等）に塗布した場合、「該分散体が該空隙に入り込んで十分な導電性を示さなくなる」と言うことがない。すなわち、平均繊維長が十分長いので、該空隙に流れ込むことがなく、該基板上でカーボンナノワイヤー同士のネットワークを形成する。その結果、本発明のカーボンナノワイヤー分散液を用いて、例えば、塗布、印刷等で形成した、膜、層、配線等は、たとえ厚さが薄くても高い導電性を有する。 Also, since the dispersion is in the form of wires instead of particles, that is, the average fiber diameter is nano size and the aspect ratio is large, a substrate having micro-sized voids (paper; substrate such as polyimide film; etc.) When applied to the above, it can not be said that "the dispersion goes into the voids and does not show sufficient conductivity". That is, since the average fiber length is sufficiently long, a network of carbon nanowires is formed on the substrate without flowing into the void. As a result, a film, a layer, a wiring or the like formed by, for example, coating, printing or the like using the carbon nanowire dispersion liquid of the present invention has high conductivity even if the thickness is thin.
　また、該基板を屈曲させたり、折り曲げたりしても、アスペクト比が大きいので、カーボンナノワイヤー同士のネットワークが切れることが少なく、導電性を維持できる。
　そのため、フレキシブル基板等の変形性基板に、特に好適に適用可能である。また、塗布面を外側にして１８０°折り曲げても、例えば、導電性、熱伝導性、放熱性、防錆性、漆黒性を全面で確保できる。特に、導電性に関しては、折り曲げ部分でも導電性が確保されるので、全面導電性の「畳んだ折り紙やフレキシブルフィルムによる構造体」も作製可能である。 In addition, since the aspect ratio is large even when the substrate is bent or bent, the network of carbon nanowires is less likely to be broken, and the conductivity can be maintained.
Therefore, it can apply especially suitably to deformable substrates, such as a flexible substrate. In addition, even if the coated surface is turned to the outside by 180 °, for example, conductivity, heat conductivity, heat dissipation, rust prevention, and jet blackness can be secured on the entire surface. In particular, with regard to the conductivity, since the conductivity is ensured even at the bent portion, it is possible to produce a "structured body made of folded origami or flexible film" which is entirely conductive.
　一般に、配線基板に用いられている銅はグラファイトより電気抵抗が低いと言われているが、それは表面の電気抵抗が大きく影響していると考えられる。炭素繊維をナノ化すると、銅をナノ化したものに比べて電気容量が大きいため、細い配線でも大きな電流を流すことが可能である。そのため、本発明のカーボンナノワイヤー分散液は、配線基板の配線の材料として特に有用である。 Generally, copper used for a wiring substrate is said to have a lower electrical resistance than graphite, but it is considered that the surface electrical resistance is greatly affected. When the carbon fiber is nano-sized, the electric capacity is larger than that of nano-ized copper, and therefore, it is possible to flow a large current even in a thin wiring. Therefore, the carbon nanowire dispersion liquid of the present invention is particularly useful as a material of the wiring of the wiring substrate.
　また、本発明のカーボンナノワイヤー分散液を用いて印刷等をして形成した配線は、導電性を有するので、該配線を陰極にして、その上に更に電解金属めっきを施すことができ、そうすることで、通常の導電体厚さ（配線厚さ）を有するプリント配線板が作製できる。例えば、電解金属めっき液として、電解銅めっき液を用いれば、基板の上に任意の厚さで銅配線を作製することが可能である。
　本発明のカーボンナノワイヤー分散液を用いてなる導電性回路形成用インクは、上記したように基板上に印刷できるだけでなく、スルーホールやビアホール内にも充填できるので、各種多層配線板に適用可能である。 Moreover, since the wiring formed by printing etc. using the carbon nanowire dispersion liquid of this invention has electroconductivity, it can use this wiring as a cathode and can apply electrolytic metal plating further on that, By doing this, a printed wiring board having a normal conductor thickness (wiring thickness) can be produced. For example, if an electrolytic copper plating solution is used as the electrolytic metal plating solution, it is possible to produce a copper wiring with an arbitrary thickness on a substrate.
The conductive circuit forming ink using the carbon nanowire dispersion liquid of the present invention can not only be printed on a substrate as described above, but can also be filled in through holes and via holes, so that it can be applied to various multilayer wiring boards It is.
　本発明のカーボンナノワイヤー分散液の製造方法は、原料として、炭素繊維、サイジング処理された炭素繊維、又は、ＣＦＲＰを用い、まず「乾式粉砕を行う」又は「乾式粉砕してあるものを原料として使用する」が、該ＣＦＲＰとして、廃棄物や不要物を使用することもできる。また、市販されているＣＦＲＰ製品を使用して、要すれば粗粉砕後、乾式粉砕する（原料として使用する）ことができる。本発明の特定の条件での粉砕と分散処理によって、得られた分散液から炭素繊維自体以外のプラスチックがほぼ除かれ、出発原料によらずほぼ同質のものとなる。 The method for producing a carbon nanowire dispersion liquid of the present invention uses carbon fiber, sized carbon fiber, or CFRP as a raw material, and first performs "dry grinding" or "dry grinding" as a raw material Although "used", wastes and unnecessary things can also be used as the CFRP. Alternatively, commercially available CFRP products can be used, and optionally after coarse grinding, dry grinding (used as a raw material). By grinding and dispersion treatment under the specific conditions of the present invention, plastics other than the carbon fiber itself are substantially removed from the obtained dispersion, and they are substantially the same regardless of the starting materials.
　本発明のカーボンナノワイヤー分散液は、分散媒を水とし、そこに更に水溶性高分子を含有させることで更に分散安定性が増し、例えば各種の導電体形成用水系塗料等として好適に使用可能である。
　また、本発明のカーボンナノワイヤー分散液は、分散媒を「窒素原子が炭化水素基で置換されていてもよい２－ピロリドン」とし、そこに更にポリイミドを含有させることで、更に分散安定性が増し、例えば各種の有機溶剤系塗料や導電性回路形成用インクとして好適に使用可能である。 The dispersion stability of the carbon nanowire dispersion liquid of the present invention can be further enhanced by using a water-soluble polymer as a dispersion medium, and can be suitably used as, for example, various water-based paint for conductor formation. It is.
Further, in the carbon nanowire dispersion liquid of the present invention, the dispersion medium is “2-pyrrolidone in which the nitrogen atom may be substituted with a hydrocarbon group”, and further contains polyimide in the dispersion stability. For example, it can be suitably used as various organic solvent paints and inks for forming conductive circuits.
乾式粉砕後であって湿式粉砕前の炭素繊維の走査型電子顕微鏡（ＳＥＭ）写真である。　（ａ）重なっている５００倍の写真　（ｂ）重なっていない５００倍の写真　（ｃ）２０００倍の写真It is a scanning electron microscope (SEM) photograph of carbon fiber after dry grinding and before wet grinding. (A) Overlapping 500x photo (b) Nonoverlapping 500x photo (c) 2000x photo 湿式粉砕後の本発明のカーボンナノワイヤー分散液に分散されているカーボンナノワイヤーの走査型電子顕微鏡（ＳＥＭ）写真である。　（ａ）５００倍の写真　（ｂ）２０００倍の写真It is a scanning electron microscope (SEM) photograph of the carbon nanowire currently disperse | distributed to the carbon nanowire dispersion liquid of this invention after wet grinding. (A) 500 times the picture (b) 2000 times the picture 湿式粉砕の条件を強過ぎる範囲として製造した参考例１のカーボンナノワイヤー分散液に分散されているカーボンナノワイヤーの粒度分布を示す図である。該カーボンナノワイヤーの平均繊維径は２００ｎｍ、平均繊維長は０．６７μｍ、平均アスペクト比は３．４である。It is a figure which shows the particle size distribution of the carbon nanowire currently disperse | distributed to the carbon nanowire dispersion liquid of the reference example 1 manufactured by setting the conditions of wet pulverization too strong. The carbon nanowires have an average fiber diameter of 200 nm, an average fiber length of 0.67 μm, and an average aspect ratio of 3.4. 湿式粉砕の条件を好適な範囲として製造した実施例２のカーボンナノワイヤー分散液に分散されているカーボンナノワイヤーの粒度分布を示す図である。該カーボンナノワイヤーの平均繊維径は２００ｎｍ、平均繊維長は１５μｍ、平均アスペクト比は７５である。It is a figure which shows the particle size distribution of the carbon nanowire currently disperse | distributed to the carbon nanowire dispersion liquid of Example 2 manufactured by setting the conditions of wet grinding as a suitable range. The average fiber diameter of the carbon nanowires is 200 nm, the average fiber length is 15 μm, and the average aspect ratio is 75.
　以下、本発明について説明するが、本発明は、以下の具体的形態に限定されるものではなく、技術的思想の範囲内で任意に変形することができる。 Hereinafter, the present invention will be described, but the present invention is not limited to the following specific embodiments, and can be arbitrarily modified within the scope of the technical idea.
＜カーボンナノワイヤー分散液＞
　本発明は、分散媒中に平均繊維径が３００ｎｍ以下であり、かつ、平均アスペクト比が３０以上２００以下のカーボンナノワイヤーが分散されたものであることを特徴とするカーボンナノワイヤー分散液である。
　本発明において、炭素繊維やカーボンナノワイヤーの、平均繊維径、平均繊維長、平均アスペクト比及び粒度分布は、実施例に記載の方法で測定し、そのように測定されたものとして定義する。平均アスペクト比は、［平均アスペクト比］＝［平均繊維長］／［平均繊維径］である。 <Carbon nanowire dispersion liquid>
The present invention is a carbon nanowire dispersion liquid characterized in that a carbon nanowire having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 to 200 is dispersed in a dispersion medium. .
In the present invention, the average fiber diameter, average fiber length, average aspect ratio and particle size distribution of carbon fibers and carbon nanowires are measured by the method described in the Examples, and defined as such measurements. The average aspect ratio is [average aspect ratio] = [average fiber length] / [average fiber diameter].
＜＜カーボンナノワイヤー＞＞
　ここで、「カーボンナノワイヤー」とは、グラファイト（黒鉛）の化学構造、炭素繊維の化学構造を有し、平均繊維径が３００ｎｍ以下であり、平均アスペクト比が３０以上のものを言う。平均繊維長が７０μｍ以上２００μｍ以下の所謂ミルドファイバーと比較して、平均繊維長が短いものであり、平均繊維径も細いものである。また、それより大きい所謂チョップドファイバーと比較すれば、当然に平均繊維長も平均繊維径も小さいものである。
　また、サイジング剤、「ＣＦＲＰ由来のプラスチック」等と言った「グラファイト等の炭素質物」以外のものの含有を排除するものではないが、実質的には含有しないものであることが好ましい。 << Carbon Nanowires >>
Here, “carbon nanowire” has a chemical structure of graphite (graphite) and a chemical structure of carbon fiber, and has an average fiber diameter of 300 nm or less and an average aspect ratio of 30 or more. Compared with so-called milled fibers having an average fiber length of 70 μm to 200 μm, the average fiber length is short and the average fiber diameter is also thin. Also, as compared with so-called chopped fibers larger than that, naturally, the average fiber length and the average fiber diameter are smaller.
Moreover, although it does not exclude inclusion of things other than "a carbonaceous material such as graphite", which is referred to as a sizing agent, "a plastic derived from CFRP", etc., it is preferable not to contain substantially.
　カーボンナノワイヤーの平均繊維径は、３００ｎｍ以下であるが、好ましくは２００ｎｍ以下であり、より好ましくは１３０ｎｍ以下であり、更に好ましくは１００ｎｍ以下であり、特に好ましくは８０ｎｍ以下である。上限が上記以下であれば、分散性や分散安定性が良くなり、得られた分散液（を有する塗料やインク）を塗布・印刷して得られる「塗膜、回路等の構造体」の、導電性、熱伝導性、放熱性、防錆性、漆黒性、均一性等が向上する。また、前記した本発明の効果を奏するようになる。
　一方、カーボンナノワイヤーの平均繊維径の下限は、特に限定はないが、粉砕、分散等を含めた製造の容易さの点等から、２０ｎｍ以上が好ましく、３０ｎｍ以上が特に好ましい。 The average fiber diameter of the carbon nanowires is 300 nm or less, preferably 200 nm or less, more preferably 130 nm or less, still more preferably 100 nm or less, and particularly preferably 80 nm or less. If the upper limit is less than or equal to the above, dispersibility and dispersion stability are improved, and the “structure such as a coating film or circuit” obtained by applying and printing the obtained dispersion (paint or ink having the same) Conductivity, thermal conductivity, heat dissipation, rust prevention, jet blackness, uniformity, etc. are improved. In addition, the effects of the present invention described above can be achieved.
On the other hand, the lower limit of the average fiber diameter of carbon nanowires is not particularly limited, but is preferably 20 nm or more, particularly preferably 30 nm or more, from the viewpoint of easiness of production including pulverization, dispersion and the like.
　カーボンナノワイヤーの平均繊維長は、６０μｍ以下が好ましく、４０μｍ以下がより好ましく、２５μｍ以下が更に好ましく、１５μｍ以下が特に好ましい。上限が上記以下であれば、分散性や分散安定性が良くなり、前記した本発明の効果を奏するようになる。
　一方、カーボンナノワイヤーの平均繊維長の下限は、１μｍ以上が好ましく、２μｍ以上がより好ましく、３μｍ以上が更に好ましく、４μｍ以上が特に好ましい。
　下限が上記以上であれば、得られた分散液（を有する塗料やインク）を塗布・印刷した場合、基板の微小凹部に入り込んで孤立してしまうことが少なく、塗布・印刷して得られる「塗膜、回路等の構造体」の、導電性、熱伝導性、放熱性、防錆性、漆黒性等が向上する。また、粉砕、分散等を含めた製造が容易になり、更に、前記した本発明の効果を奏するようになる。 60 micrometers or less are preferable, as for the average fiber length of carbon nanowire, 40 micrometers or less are more preferable, 25 micrometers or less are still more preferable, and 15 micrometers or less are especially preferable. If the upper limit is less than or equal to the above, dispersibility and dispersion stability are improved, and the above-described effects of the present invention are exhibited.
On the other hand, the lower limit of the average fiber length of the carbon nanowire is preferably 1 μm or more, more preferably 2 μm or more, still more preferably 3 μm or more, and particularly preferably 4 μm or more.
When the lower limit is at least the above, when the obtained dispersion liquid (paint or ink having the same) is applied and printed, it hardly enters the minute depressions of the substrate and becomes isolated, and obtained by application and printing Conductivity, thermal conductivity, heat dissipation, rust resistance, jet blackness, etc. of a structure such as a coating film or a circuit are improved. In addition, manufacturing including pulverization, dispersion and the like is facilitated, and the above-described effects of the present invention can be achieved.
　カーボンナノワイヤーの平均アスペクト比は、３０以上２００以下であるが、好ましくは４０以上１８０以下であり、より好ましくは５０以上１７０以下であり、特に好ましくは６０以上１５０以下である。
　カーボンナノワイヤーの平均アスペクト比の下限が上記以上であると、上記した「平均繊維径の上限が上記以下である効果や平均繊維長の下限が上記以上である効果と同様の効果」を奏し、カーボンナノワイヤーの平均アスペクト比の上限が上記以下であると、上記した「平均繊維径の下限が上記以上である効果や平均繊維長の上限が上記以下である効果と同様の効果」を奏する。 The average aspect ratio of the carbon nanowires is 30 or more and 200 or less, preferably 40 or more and 180 or less, more preferably 50 or more and 170 or less, and particularly preferably 60 or more and 150 or less.
When the lower limit of the average aspect ratio of the carbon nanowire is above, the above-mentioned "effect similar to the effect that the upper limit of the average fiber diameter is below or above and the effect that the lower limit of the average fiber length is above" is exhibited. When the upper limit of the average aspect ratio of the carbon nanowires is equal to or less than the above, the above-mentioned "effect similar to the effect that the lower limit of the average fiber diameter is more than the above or the effect that the upper limit of the average fiber length is the following" is exhibited.
　実施例に記載の方法で測定される粒度分布は、例えば図３に示したように、粒径（横軸）が２桁未満の範囲に９５％が分布しているようなものより、例えば図４に示したように、粒径（横軸）が２桁以上の範囲に９５％が分布しているようなものの方が、平均繊維長が長いまま維持され、平均アスペクト比が大きい状態になるので好ましい。過度の湿式粉砕は、平均繊維長を短くし過ぎて、平均アスペクト比を小さくしてしまう場合がある。 The particle size distribution measured by the method described in the examples is, for example, as shown in FIG. 3, in which 95% is distributed in the range of less than two digits in particle diameter (horizontal axis), for example, FIG. As shown in 4, when the particle diameter (horizontal axis) is 95% distributed in the range of 2 digits or more, the average fiber length is maintained longer and the average aspect ratio becomes larger. So preferred. Excessive wet grinding may reduce the average fiber length too much and may reduce the average aspect ratio.
＜＜分散媒＞＞
　本発明のカーボンナノワイヤー分散液の分散媒としては、塗料、インク等の溶媒若しくは分散媒として使用されるものや、塗料、インク等を製造する際のマスターバッチの溶媒若しくは分散媒として使用されるものが挙げられる。
　限定はされないが、具体的には、例えば、以下のものが挙げられる。
　水；エチレングリコール；ジエチレングリコール、トリエチレングリコール等のエチレングリコール縮合物；それらのジアセテート；エチレングリコールモノエチルエーテル、エチレングリコールモノフェニルエーテル等のエチレングリコールモノアルキル（又はフェニル）エーテル；それらのモノアセテート；エチレングリコールジエチルエーテル、エチレングリコールジフェニルエーテル等のエチレングリコールジアルキル（又はジフェニル）エーテル；上記「エチレングリコール」を「ジエチレングリコール」又は「トリエチレングリコール」に代えた溶剤；上記の「エチレングリコール」を「プロピレングリコール」に代えた溶剤；等が挙げられる。 << Dispersion medium >>
The dispersion medium of the carbon nanowire dispersion liquid of the present invention is used as a solvent or dispersion medium for paints, inks, etc., or as a solvent or dispersion medium for masterbatches when producing paints, inks, etc. The thing is mentioned.
Specific examples include, but are not limited to, the following.
Water; ethylene glycol; ethylene glycol condensates such as diethylene glycol and triethylene glycol; diacetates thereof; ethylene glycol monoalkyl (or phenyl) ethers such as ethylene glycol monoethyl ether and ethylene glycol monophenyl ether; monoacetates thereof Ethylene glycol dialkyl (or diphenyl) ethers such as ethylene glycol diethyl ether, ethylene glycol diphenyl ether; solvents obtained by replacing the above "ethylene glycol" with "diethylene glycol" or "triethylene glycol";"propyleneglycol" above And the like.
　また、３，５，５－トリメチルヘキサノール、２－エチル－１，３－ヘキサンジオール、２－メチル－２，４－ペンタンジオール等のアルコール；それらのカルボン酸エステル；γ－ブチルラクトン等の環状エステル；プロピレンカーボネート、ブチレンカーボネート、ビニルカーボネート等の炭酸エステル；ピロリドン、Ｎ－メチルピロリドン（ＮＭＰ）、Ｎ－エチルピロリドン等の「窒素原子が炭化水素基で置換されていてもよいピロリドン」（「ピロリドン」は、「２－ピロリドン」が好ましい）；等が挙げられる。 Also, alcohols such as 3,5,5-trimethylhexanol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol; carboxylic acid esters thereof; cyclic esters such as γ-butyl lactone Carbonates such as propylene carbonate, butylene carbonate, vinyl carbonate, etc .; "pyrrolidones whose nitrogen atoms may be substituted by hydrocarbon groups" such as pyrrolidone, N-methyl pyrrolidone (NMP), N-ethyl pyrrolidone etc. ("pyrrolidone" And “2-pyrrolidone” is preferable); and the like.
　更に、酢酸；テトラヒドロフラン；ベンゼン、シクロヘキサン、キシレン等の炭化水素；酢酸メチル、酢酸エチル、フタル酸ジオクチル、芳香族エステル等のエステル；アセトフェノン、メチルエチルケトン（ＭＥＫ）、シクロヘキサノン、アセトン等のケトン；四塩化炭素、クロロホルム、トリクロロエチレン、ジクロロメタン等の塩素含有溶剤；オクチレングリコール、アセトンアルコール、イソプロピルアルコール等のアルコール；二硫化炭素；ピリジン、ニトロエタン、アセトニトリル等の窒素含有溶剤；ジオキサン；ε－カプロラクトン、γ－ブチロラクトン（ＧＢＬ）等のラクトン；等が挙げられる。 Further, acetic acid; tetrahydrofuran; hydrocarbons such as benzene, cyclohexane and xylene; esters such as methyl acetate, ethyl acetate, dioctyl phthalate and aromatic esters; ketones such as acetophenone, methyl ethyl ketone (MEK), cyclohexanone and acetone; carbon tetrachloride Chlorine-containing solvents such as chloroform, trichloroethylene and dichloromethane; alcohols such as octylene glycol, acetone alcohol and isopropyl alcohol; carbon disulfide; nitrogen-containing solvents such as pyridine, nitroethane and acetonitrile; dioxane; ε-caprolactone, γ-butyrolactone ( And lactones such as GBL).
　上記分散媒は、単独又は２種以上を混合して用いられる。 The dispersion media may be used alone or in combination of two or more.
　中でも、カーボンナノワイヤー分散液の「塗料やインク等と言った用途」が広いこと、粉砕性、分散性が良いこと、特定の界面活性剤が好適に機能すること、分散安定性が良いこと、取り扱いが安全・簡単であること、等の点から水が好ましい。該水は、脱塩水、蒸留水等の純水がより好ましい。 Among them, carbon nanowire dispersions have a wide range of uses such as paints and inks, etc., that they have good crushability and dispersibility, that a specific surfactant suitably functions, and that their dispersion stability is good, Water is preferred from the viewpoint of safe and easy handling. The water is more preferably pure water such as demineralized water or distilled water.
　また、中でも、本発明のカーボンナノワイヤー分散液の特に好適な用途が、導電性塗料や導電性インクであるため、その基板であるポリイミド、ポリエポキシ等のポリマー基板にマッチングしている；ビーズミル処理による粉砕との相性が良い；カーボンナノワイヤーの分散性が特に好適である；特定の界面活性剤が好適に機能する；等の理由から、ピロリドン、Ｎ－メチルピロリドン、Ｎ－エチルピロリドン等の「窒素原子が炭化水素基で置換されていてもよいピロリドン」、メチルエチルケトン（ＭＥＫ）等のケトン：γ－ブチロラクトン（ＧＢＬ）等のラクトン；等が好ましく、「窒素原子が炭化水素基で置換されていてもよい２－ピロリドン」、メチルエチルケトン（ＭＥＫ）、γ－ブチロラクトン（ＧＢＬ）等がより好ましく、Ｎ－メチル－２－ピロリドン（ＮＭＰ）が特に好ましい。 Further, among the above, the particularly suitable use of the carbon nanowire dispersion liquid of the present invention is a conductive paint or a conductive ink, so that it is matched to a polymer substrate such as polyimide or polyepoxy as the substrate; bead mill treatment The compatibility with the pulverization by carbon dioxide is good; the dispersibility of carbon nanowires is particularly suitable; a specific surfactant functions suitably; and so on, such as pyrrolidone, N-methyl pyrrolidone, N-ethyl pyrrolidone etc. Pyrrolidone in which nitrogen atom may be substituted with a hydrocarbon group, ketone such as methyl ethyl ketone (MEK): lactone such as γ-butyrolactone (GBL); etc. are preferable, and “nitrogen atom is substituted with a hydrocarbon group More preferable are 2-pyrrolidone, "methyl ethyl ketone (MEK), γ-butyrolactone (GBL), etc., N Particular preference is given to methyl-2-pyrrolidone (NMP).
＜＜分散液中のカーボンナノワイヤーの含有割合＞＞
　本発明のカーボンナノワイヤー分散液中に分散されているカーボンナノワイヤーの含有割合は、特に限定はないが、カーボンナノワイヤー分散液全体に対して、０．０１質量％以上２０質量％以下が好ましく、０．１質量％以上１５質量％以下がより好ましく、０．３質量％以上１０質量％以下が更に好ましく、１質量％以上６質量％以下が特に好ましい。 << Contents of Carbon Nanowires in Dispersion >>
The content ratio of the carbon nanowires dispersed in the carbon nanowire dispersion liquid of the present invention is not particularly limited, but preferably 0.01% by mass or more and 20% by mass or less with respect to the whole carbon nanowire dispersion liquid. 0.1 mass% or more and 15 mass% or less are more preferable, 0.3 mass% or more and 10 mass% or less are more preferable, and 1 mass% or more and 6 mass% or less are particularly preferable.
　含有割合が上記下限以上であると、分散液が薄過ぎずに分散媒が無駄にならない；必要以上に分散液の体積が大きくならない；分散液を塗料やインク等の製造に使用する場合に過剰の分散媒が含有されていないので用途が広がる；等の効果がある。
　一方、含有割合が上記上限以下であると、カーボンナノワイヤーの分散性や分散安定性が良くなる；ビーズミル処理等の粉砕に際して、分散液の粘度や濃度が高くなり過ぎずに、分散性が向上したり分散時間の短縮がなされたりする；アスペクト比が大きなカーボンナノワイヤーが得られる；等の効果がある。 When the content ratio is at least the above lower limit, the dispersion liquid is not too thin and the dispersion medium is not wasted; the volume of the dispersion liquid is not increased more than necessary; the dispersion liquid is excessive when used in the production of paints, inks, etc. Since the dispersion medium of (1) is not contained, the use is expanded;
On the other hand, the dispersibility and the dispersion stability of the carbon nanowires are improved when the content ratio is not more than the above upper limit; the dispersibility is improved without the viscosity and the concentration of the dispersion becoming too high at the time of grinding such as bead milling And the dispersion time is shortened; carbon nanowires with a large aspect ratio can be obtained; and so on.
＜カーボンナノワイヤー分散液の製造方法＞
　本発明の「カーボンナノワイヤー分散液の製造方法」は、「上記したカーボンナノワイヤー分散液」の製造方法であって、
　炭素繊維を乾式粉砕し、又は、乾式粉砕された炭素繊維を用意し、その後、分散媒中で湿式粉砕することによって、該炭素繊維を粉砕しつつ該分散媒に分散させる方法であって、
　該湿式粉砕は、該分散媒の中に、該乾式粉砕した炭素繊維を含有させ、陰イオン系界面活性剤の存在下でビーズミル処理することによって、該炭素繊維を平均繊維径３００ｎｍ以下、かつ平均アスペクト比３０以上２００以下にすることを特徴とする。 <Production Method of Carbon Nanowire Dispersion>
The “method for producing a carbon nanowire dispersion” of the present invention is a method for producing the “carbon nanowire dispersion described above”, and
A method of dry-pulverizing carbon fibers or preparing dry-pulverized carbon fibers and thereafter dispersing the carbon fibers in the dispersion medium while grinding the carbon fibers by wet-pulverizing in the dispersion medium,
In the wet grinding, the dry ground carbon fiber is contained in the dispersion medium, and the carbon fiber is subjected to bead milling in the presence of an anionic surfactant, whereby the carbon fiber has an average fiber diameter of 300 nm or less and an average It is characterized in that the aspect ratio is 30 or more and 200 or less.
＜＜原料である炭素繊維＞＞
　本発明においては、原料となる上記「炭素繊維」には、サイジング処理された炭素繊維；炭素繊維強化プラスチック（carbon fiber reinforced plastics）（以下、「ＣＦＲＰ」と略記する）；炭素繊維強化炭素複合材料；ＪＩＳ規格で言う９０質量％以上が炭素質物である炭素繊維；炭素繊維単身若しくは炭素質物単身；所謂炭素繊維と言われているもの；等が含まれる。 << Carbon fiber as raw material >>
In the present invention, the above-mentioned "carbon fiber" as a raw material includes carbon fibers subjected to sizing treatment; carbon fiber reinforced plastics (hereinafter abbreviated as "CFRP"); carbon fiber reinforced carbon composite material 90% by mass or more according to the JIS standard is a carbonaceous material; carbon fiber alone or carbon material single; so-called carbon fibers; and the like.
　該ＣＦＲＰは、炭素繊維をマトリックス樹脂に含有・並存させたプリプレグ等をオートクレーブ内で加圧下に加熱したもの、マイクロ波等を用いて加熱したりして成型したもの等何れでもよい。
　本発明のカーボンナノワイヤー分散液の製造方法によれば、陰イオン系界面活性剤の存在下でビーズミル処理することによって、ＣＦＲＰ等の「炭素繊維」を縦に解き、平均繊維長に対し平均繊維径を特異的に細くすることができるので、原料となる上記「炭素繊維」として、ＣＦＲＰを使用することが、本発明の特徴を生かすためにも特に好ましい。 The CFRP may be a prepreg obtained by causing carbon fiber to be contained in a matrix resin in a matrix resin, which is heated under pressure in an autoclave, or a molded by heating using a microwave or the like.
According to the method for producing a carbon nanowire dispersion liquid of the present invention, "carbon fibers" such as CFRP are longitudinally unwound by bead milling in the presence of an anionic surfactant, and the average fiber length relative to the average fiber length It is particularly preferable to use CFRP as the above-mentioned "carbon fiber" as a raw material because the diameter can be specifically narrowed, in order to take advantage of the features of the present invention.
　「原料となる上記『炭素繊維』に含まれる炭素繊維単身以外の物質」は、湿式粉砕の過程で多くが分散媒中に移行し、分散されているカーボンナノワイヤーには殆ど又は全く残っていないが、カーボンナノワイヤーに該物質が残存・付着している場合を、本発明は排除するものではない。なお、上記「分散媒中に移行」とは、分散媒に溶解する場合；微分散や塊となって分散する場合；分散媒中で浮遊又は分離する場合；等がある。 Most of the "substance other than carbon fiber single substance contained in the above-mentioned" carbon fiber "as the raw material" is transferred to the dispersion medium in the process of wet pulverization, and little or no residue remains in the dispersed carbon nanowires However, the present invention does not exclude the case where the substance remains or adheres to the carbon nanowires. The above "transfer into the dispersion medium" may be, for example, when it is dissolved in the dispersion medium; when it is finely dispersed or lumped and dispersed; when it is suspended or separated in the dispersion medium;
　本発明の「カーボンナノワイヤー分散液の製造方法」においては、まず、「炭素繊維」を乾式粉砕するか、又は、乾式粉砕された炭素繊維を用意する。すなわち、炭素繊維を（改めて）乾式粉砕してもよいし、既に乾式粉砕されている炭素繊維を入手して使用してもよいが、後述するビーズミル処理する前に、炭素繊維を乾式粉砕することが好ましい。 In the “method of producing a carbon nanowire dispersion” of the present invention, first, “carbon fiber” is dry-ground or dry-ground carbon fiber is prepared. That is, carbon fibers may be dry-ground (renewed), or carbon fibers which have already been dry-ground may be obtained and used, but dry-grinding carbon fibers before bead mill processing described later Is preferred.
　乾式粉砕する前の原料である「炭素繊維」は、ある程度粉砕等されたチョップドファイバー、ミルドファイバー等であっても、大きなＣＦＲＰ等を要すれば粗粉砕したものであってもよい。また、廃棄物であったり不要になったりしたＣＦＲＰ（を粗粉砕したもの）であってもよい。 The "carbon fiber" which is a raw material before dry grinding may be a chopped fiber, a milled fiber, etc. crushed to some extent or the like, or it may be roughly crushed if a large CFRP etc. is required. In addition, it may be a waste material or CFRP (which is roughly crushed) which has become unnecessary.
　「不要になったＣＦＲＰ」とは、一般に使用・販売されているＣＦＲＰで不要となったもの、廃棄物であるＣＦＲＰ、メーカー等で試作品（失敗品を含む）として出てきたＣＦＲＰ等が挙げられる。限定はされないが、具体的には、例えば、ゴルフクラブのシャフト；テニスラケットの枠材；釣り竿；自動車のフレームや種々のパーツ；飛行機の翼や種々のパーツ；船・ロケット・宇宙船等の種々のパーツ；楽器、携帯品等のケース；等が挙げられる。 Examples of “CFRPs that are no longer needed” include those that are no longer needed for commonly used and sold CFRPs, CFRPs that are wastes, and CFRPs that have come out as prototypes (including failed products) by manufacturers etc. Be Specifically, but not limited to, for example, golf club shafts; tennis racquet frame materials; fishing rods; car frames and various parts; plane wings and various parts; Parts; cases of musical instruments, portable items, etc .;
　原料である「炭素繊維」は、アクリル繊維を高温で炭化して得られるパン系（ＰＡＮ系）の炭素繊維であっても、ピッチを高温で炭化して得られるピッチ系（ＰＩＴＣＨ系）の炭素繊維であってもよいが、導電性に優れる点、アスペクト比が大きいカーボンナノワイヤーが得られ易い点等から、ピッチ系（ＰＩＴＣＨ系）の炭素繊維であることが好ましい。 Even if it is a bread-based (PAN-based) carbon fiber obtained by carbonizing acrylic fibers at a high temperature, the “carbon fiber” as a raw material, a pitch-based (PITCH-based) carbon obtained by carbonizing a pitch at a high temperature Although it may be a fiber, it is preferably a pitch-based (PITCH-based) carbon fiber from the viewpoint of excellent conductivity and the ease with which a carbon nanowire with a large aspect ratio can be obtained.
＜＜乾式粉砕＞＞
　本発明においては、まず乾式粉砕がなされるが、該乾式粉砕としては、「サイクロンミル等の気流粉砕機；ジェットミル；等」を用いた気流式粉砕；「クラッシャーミル、ピンミル、カッターミル、ハンマーミル、軸流ミル等」を用いた「回転衝突式粉砕、ロール式粉砕、媒体式粉砕、石臼式粉砕、カッター式粉砕」；等が挙げられる。中でも、サイクロンミル、ジェットミル等を用いた気流式粉砕が、本発明における乾式粉砕として特に好ましい。
　サイクロンミルによる気流式粉砕は、インペラ（回転翼）の回転によって気流を発生させ、気流中に投入された対象物を乾式で粉砕して微粒子を製造するものである。また、ジェットミルによる気流粉砕は、衝突板に対象物を衝突させて対象物を乾式で粉砕して微粒子を製造するものである。 << dry grinding >>
In the present invention, dry grinding is first performed, and as the dry grinding, pneumatic grinding using "air flow grinding machine such as cyclone mill; jet mill; etc.";"crusher mill, pin mill, cutter mill, hammer" Mills, axial flow mills, etc. “rotational impact grinding, roll grinding, medium grinding, stone grinding, cutter grinding” and the like can be mentioned. Among them, pneumatic pulverization using a cyclone mill, jet mill or the like is particularly preferable as the dry pulverization in the present invention.
In the air flow type pulverization using a cyclone mill, an air flow is generated by rotation of an impeller (rotor blade), and an object placed in the air flow is dryly crushed to produce fine particles. In the air flow grinding using a jet mill, the target is made to collide with the collision plate, and the target is dry ground to produce fine particles.
　乾式粉砕に、クラッシャーミル、ピンミル、カッターミル、ハンマーミル、軸流ミル等を用いると、（コストを抑えつつ）平均繊維径や平均繊維長を十分に小さくすることが難しい、繊維径や繊維長の分布が広過ぎる、特に大きい方にテーリングする；等の場合がある。
　一方、サイクロンミル、ジェットミル等を用いた気流式粉砕では、上記したような問題が生じず、その後のビーズミルを用いた湿式粉砕に供するのに好ましい平均繊維径、平均繊維長及びそれらの分布（粒度分布）とすることが可能である。 When crusher mill, pin mill, cutter mill, hammer mill, axial flow mill etc. are used for dry grinding, it is difficult to make the average fiber diameter and average fiber length sufficiently small (while keeping the cost down), fiber diameter and fiber length Distribution is too broad, particularly tailing to larger ones.
On the other hand, in the air flow type pulverization using a cyclone mill, jet mill or the like, the above-mentioned problems do not occur, and the average fiber diameter, average fiber length and their distribution preferred for subsequent wet pulverization using a bead mill Particle size distribution).
　サイクロンミルとしては、市販されている装置も好適に使用できる。市販品としては、例えば、株式会社静岡プラント製のサイクロンミル、静岡製機株式会社製のサイクロンミル、株式会社西村機械製作所製のスーパーパウダーミル、三庄インダストリー株式会社製のトルネードミル、古河産機システムズ株式会社製のドリームミル等が挙げられる。 An apparatus marketed can also be used conveniently as a cyclone mill. As a commercial product, for example, Cyclone mill manufactured by Shizuoka Plant Co., Ltd., Cyclone mill manufactured by Shizuoka Machine Co., Ltd., super powder mill manufactured by Nishimura Machinery Co., Ltd., tornado mill manufactured by Mitaka Industry Co., Ltd., Furukawa Sangyo Co., Ltd. A Dream Mill manufactured by Systems Co., Ltd. may, for example, be mentioned.
　上記サイクロンミルの構造は、特に限定はないが、１個又は２個以上のインペラを有し、該インペラが発生させる旋回気流によって主に粉砕対象物同士を衝突させて粉砕するものであることが、前記気流粉砕機を使用することによる前記効果を奏し易い；金属コンタミが非常に少ない；等の点から特に好ましい。
　該インペラは、それぞれ同方向に回転させても、反対方向に回転させてもよい。 The structure of the above-mentioned cyclone mill is not particularly limited, but it has one or more impellers, and it is mainly intended that the objects to be crushed are collided and crushed by the swirling air flow generated by the impellers. It is particularly preferable from the viewpoint of easily achieving the effects by using the air flow crusher; very little metal contamination; and the like.
The impellers may be rotated in the same direction or in opposite directions, respectively.
　特に限定はないが、上記気流粉砕機は、内部に分級機能を有し、分級された粗粉が内部で再度粉砕されると共に、分級された微粉が取り出せるようになっているものであることが、粗粉除去のため、狭い分布を得るため等の点から特に好ましい。上記分級機能は、特に限定はないが、サイクロン分級機能であることが分級能力の高い点から特に好ましい。 Although there is no particular limitation, it is possible that the air flow crusher has a classification function inside, and the classified coarse powder can be crushed again inside and the classified fine powder can be taken out. Particularly preferred in view of obtaining a narrow distribution for removing coarse powder. The classification function is not particularly limited, but is preferably a cyclone classification function from the viewpoint of high classification ability.
　サイクロンミルを使用する場合の雰囲気温度又は設定温度は、特に限定はなく使用する装置の使用方法に従えばよいが、好ましくは０℃以上５０℃以下、特に好ましくは５℃以上３５℃以下である。また、サイクロンミルを使用する場合のインペラ回転数も、使用する装置の使用方法に従えばよいが、好ましくは４０００ｒｐｍ以上２００００ｒｐｍ以下、特に好ましくは８０００ｒｐｍ以上１５０００ｒｐｍ以下である。 The ambient temperature or setting temperature in the case of using a cyclone mill is not particularly limited and may be in accordance with the use of the apparatus used, but is preferably 0 ° C. to 50 ° C., particularly preferably 5 ° C. to 35 ° C. . The impeller rotational speed in the case of using a cyclone mill may be in accordance with the method of use of the apparatus used, but is preferably 4000 rpm or more and 20000 rpm or less, and particularly preferably 8000 rpm or more and 15000 rpm or less.
　ジェットミルとしては、市販されている装置も好適に使用できる。市販しているメーカーとしては、例えば、株式会社セイシン企業、ホソカワミクロン株式会社、日本ニューマチック株式会社、日清エンジニアリング株式会社が挙げられる。 A commercially available apparatus can also be suitably used as a jet mill. Examples of commercially available manufacturers include Seishin Enterprise Co., Ltd., Hosokawa Micron Corporation, Nippon Pneumatic Mfg Co., Ltd., Nisshin Engineering Co., Ltd., and the like.
　ジェットミルを使用する場合の雰囲気温度又は設定温度は、特に限定はなく使用する装置の使用方法に従えばよいが、好ましくは０℃以上５０℃以下、特に好ましくは５℃以上３５℃以下である。
　また、ジェット噴射圧又は噴射速度も、使用する装置の使用方法に従えばよいが、最も好ましくは、２０℃、６ｂａｒ（０．６ＭＰａＧ）の圧縮空気が粉砕ガスとして使われ、５００ｍ／ｓのノズル噴出速度が最も好ましい。好ましくは上記値の±２０％の値範囲であり、特に好ましくは上記値の±１０％の値範囲である。 The ambient temperature or setting temperature in the case of using a jet mill is not particularly limited and may be in accordance with the method of use of the apparatus used, but is preferably 0 ° C. or more and 50 ° C. or less, particularly preferably 5 ° C. or more and 35 ° C. or less .
Also, the jet injection pressure or injection speed may be in accordance with the method of use of the apparatus used, but most preferably, compressed air at 20 ° C. and 6 bar (0.6 MPaG) is used as a grinding gas, and a 500 m / s nozzle The spouting speed is most preferred. The preferred range is ± 20% of the above value, and particularly preferred is ± 10% of the above value.
　本発明において原料となる上記「炭素繊維」を、特に限定はないが平均繊維長７０μｍ以下になるまで乾式粉砕してから湿式粉砕をすることが好ましい。
　平均繊維長が７０μｍ以下になるまで乾式粉砕してから湿式粉砕をすることによって、カーボンナノワイヤー分散液中のカーボンナノワイヤーの平均繊維径、平均繊維長、形状分布等が前記した必須の範囲又は好適な範囲に収まり易くなる。 There is no particular limitation on the above-mentioned "carbon fiber" which is a raw material in the present invention, but it is preferable to dry-pulverize it until the average fiber length becomes 70 μm or less and then wet-pulverize.
By carrying out dry grinding until the average fiber length becomes 70 μm or less and then carrying out wet grinding, the required range of the average fiber diameter, average fiber length, shape distribution, etc. of carbon nanowires in the carbon nanowire dispersion liquid or It becomes easy to be included in the suitable range.
　乾式粉砕によって、平均繊維長を７０μｍ以下にすることが好ましいが、より好ましくは５μｍ以上６０μｍ以下、更に好ましくは１０μｍ以上５０μｍ以下、特に好ましくは１５μｍ以上４０μｍ以下にする。
　上限が上記より大きいと、次の工程であるビーズミルによる湿式粉砕で、該湿式粉砕の条件を調整しても、最終的にカーボンナノワイヤーの平均繊維径が３００ｎｍ以下になり難い場合、又は、最終的に上記した（より好ましい若しくは特に好ましい）カーボンナノワイヤーの平均繊維径になり難い等の場合がある。また、該湿式粉砕の条件を調整しても、最終的にカーボンナノワイヤーの平均繊維長や平均アスペクト比が上記した（「より好ましい」若しくは「特に好ましい」）範囲になり難い等の場合がある。 The average fiber length is preferably 70 μm or less by dry grinding, more preferably 5 μm to 60 μm, still more preferably 10 μm to 50 μm, and particularly preferably 15 μm to 40 μm.
When the upper limit is larger than the above, even if the average fiber diameter of the carbon nanowires hardly reaches 300 nm or less finally even if the conditions of the wet grinding are adjusted by wet grinding using a bead mill which is the next step, or In some cases, the average fiber diameter of the above-described (more preferable or particularly preferable) carbon nanowires is difficult to be achieved. In addition, even if the conditions of the wet pulverization are adjusted, the average fiber length and average aspect ratio of the carbon nanowires may hardly fall in the above-mentioned ("more preferable" or "particularly preferable") range. .
　一方、下限が上記より小さいと、湿式粉砕後にカーボンナノワイヤーの平均繊維長が該下限以上にはなり得ないので、最終的にカーボンナノワイヤーの平均繊維長や平均アスペクト比が上記した（「より好ましい」若しくは「特に好ましい」）範囲になり難い等の場合がある。特に、最終的なカーボンナノワイヤーの平均アスペクト比が小さくなり過ぎる場合がある。 On the other hand, if the lower limit is smaller than the above, the average fiber length of the carbon nanowires can not exceed the lower limit after wet grinding, so finally the average fiber length and average aspect ratio of the carbon nanowires are described above (" There is a case where it is difficult to be in the range of “preferred” or “particularly preferred”. In particular, the average aspect ratio of the final carbon nanowire may be too small.
　乾式粉砕によっては、そもそも平均繊維径を小さくし難く、すなわち平均アスペクト比が大きくなるように粉砕し難く、また乾式粉砕で無理に平均繊維径を小さくしてしまっては平均繊維長も短くなってしまい、湿式粉砕後の最終的なアスペクト比が好適な範囲に収まり難くなるが、乾式粉砕後の平均繊維径は、３０００ｎｍ以上が好ましく、５０００ｎｍ以上１５０００ｎｍ以下が特に好ましい。 By dry grinding, it is difficult to reduce the average fiber diameter in the first place, that is, it is difficult to grind so as to increase the average aspect ratio, and if the average fiber diameter is forcibly reduced by dry grinding, the average fiber length becomes short. As a result, the final aspect ratio after wet grinding hardly falls within the preferable range, but the average fiber diameter after dry grinding is preferably 3000 nm or more, and particularly preferably 5000 nm or more and 15000 nm or less.
　乾式粉砕後の平均アスペクト比は、特に限定はないが、１０以下であることが好ましく、より好ましくは７以下、特に好ましくは０．５以上５以下である。
　乾式粉砕によっては、そもそも平均アスペクト比を上記上限より大きくし難い。すなわち、平均アスペクト比を上記上限より大きくできる程度に平均繊維径を小さくし難い。
　本発明は、乾式粉砕によって、比較的大きな平均繊維径や比較的小さな平均アスペクト比にしておいても、或いは、しておくことによって、後の特定の湿式粉砕によって、最終的に前記したような、好適な「小さな平均繊維径や大きな平均アスペクト比」が得られることを見出してなされた。 The average aspect ratio after dry pulverization is not particularly limited, but is preferably 10 or less, more preferably 7 or less, and particularly preferably 0.5 or more and 5 or less.
Depending on dry grinding, it is difficult to make the average aspect ratio larger than the upper limit. That is, it is difficult to reduce the average fiber diameter to such an extent that the average aspect ratio can be larger than the upper limit.
The present invention can be finally achieved by dry-grinding, even with a relatively large average fiber diameter or relatively small average aspect ratio, or by specific wet-grinding later on. It has been found that suitable "small average fiber diameter and large average aspect ratio" can be obtained.
　本発明のカーボンナノワイヤー分散液の製造方法においては、湿式粉砕前の「上記乾式粉砕後の炭素繊維」の平均繊維径が３０００ｎｍ以上であり、かつ、平均アスペクト比が１０以下であることが特に好ましい。 In the method for producing a carbon nanowire dispersion according to the present invention, it is particularly preferable that the average fiber diameter of "the above-mentioned dry-ground carbon fiber" before wet grinding is 3000 nm or more and the average aspect ratio is 10 or less preferable.
＜＜湿式粉砕＞＞
　乾式粉砕の後に湿式粉砕をするが、該湿式粉砕は、上記分散媒の中に、上記乾式粉砕した炭素繊維を含有させ、陰イオン系界面活性剤の存在下でビーズミル処理することによって、所定のカーボンナノワイヤーの形状（平均繊維径、平均繊維長、平均アスペクト比）や粒度分布にする。
　すなわち、最終的に炭素繊維を平均繊維径３００ｎｍ以下、かつ平均アスペクト比３０以上２００以下のカーボンナノワイヤーにし、更に前記した＜カーボンナノワイヤー分散液＞＜＜カーボンナノワイヤー＞＞の（（より若しくは特に）好ましい）範囲の形状や粒度分布のカーボンナノワイヤーにする。
　なお、乾式粉砕と湿式粉砕の間には、他の処理を挟んでもよいことは言うまでもない。該「他の処理」としては、予備混合、予備調液等が挙げられる。 << Wet grinding >>
Wet grinding is carried out after dry grinding, wherein the wet grinding contains the dry ground carbon fiber in the dispersion medium and is subjected to bead milling by bead milling in the presence of an anionic surfactant. The shape (average fiber diameter, average fiber length, average aspect ratio) and particle size distribution of carbon nanowires are used.
That is, finally, carbon fibers are formed into carbon nanowires having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 or more and 200 or less, and the above-described <carbon nanowire dispersion><< carbon nanowires >> Particularly preferred is the formation of carbon nanowires in a range of shapes and particle size distributions.
It goes without saying that another process may be interposed between dry grinding and wet grinding. Examples of the "other processing" include pre-mixing, pre-mixing, and the like.
＜＜＜湿式粉砕の方式・装置・条件＞＞＞
　湿式粉砕は、ビーズミルを用いてビーズミル処理をする。それによって、はじめて前記したような特定の形状や粒度分布のカーボンナノワイヤーと、カーボンナノワイヤー分散液が得られた。
　ビーズミル処理の条件は、前記した特定の、平均繊維径、平均繊維長、平均アスペクト比、及び、粒度分布のカーボンナノワイヤーとカーボンナノワイヤー分散液が得られるように調整する。下記するビーズミル処理の条件は、乾式粉砕後の炭素繊維を粉砕して最終的に前記した形状のカーボンナノワイヤーを得るために極めて重要であり、ビーズミル処理における各条件の組み合わせは、容易に選択できる当たり前の範囲ではない。 <<< Method, Equipment, Conditions of Wet Grinding >>>
In wet grinding, bead milling is performed using a bead mill. As a result, carbon nanowires of the specific shape and particle size distribution as described above and a carbon nanowire dispersion liquid are obtained for the first time.
The conditions for bead milling are adjusted so as to obtain the above-mentioned specific mean fiber diameter, mean fiber length, mean aspect ratio, and particle size distribution of carbon nanowire and carbon nanowire dispersion liquid. The conditions for bead milling described below are extremely important in order to obtain carbon nanowires of the above-described shape by finally pulverizing carbon fibers after dry pulverization, and the combination of the respective conditions in bead milling can be easily selected. It is not a natural range.
　ビーズミルに用いられるビーズの材質としては、ガラス、アルミナ、ジルコン（ジルコニア・シリカ系セラミックス）、ジルコニア、金属（スチール）等が挙げられるが、ジルコニア等が好ましく、ジルコニアが硬度等の点から特に好ましい。 Examples of the material of the beads used in the bead mill include glass, alumina, zircon (zirconia-silica ceramic), zirconia, metal (steel) and the like, with zirconia and the like being preferable and zirconia being particularly preferable from the viewpoint of hardness and the like.
　ビーズミルに用いられるビーズのビーズ径は、０．１ｍｍ以上１．５ｍｍ以下が好ましく、０．３ｍｍ以上１ｍｍ以下がより好ましく、０．５ｍｍ以上０．８ｍｍ以下が特に好ましい。
　ビーズ径が大き過ぎると、ビーズミル容器内のビーズ個数が減り、接触点が減ることになり、好適に分散できない場合、平均繊維径等を十分小さく粉砕できない場合等がある。一方、ビーズ径が小さ過ぎると、好適に分散できない場合、粉砕に時間がかかり過ぎる場合等がある。 The bead diameter of the beads used in the bead mill is preferably 0.1 mm or more and 1.5 mm or less, more preferably 0.3 mm or more and 1 mm or less, and particularly preferably 0.5 mm or more and 0.8 mm or less.
If the bead diameter is too large, the number of beads in the bead mill container will decrease and the contact point will decrease, and if it can not be suitably dispersed, the average fiber diameter etc. may not be reduced sufficiently. On the other hand, when the bead diameter is too small, when it can not be suitably dispersed, pulverization may take too long.
　ビーズミルに用いられるビーズ充填率としては、４５％以上８５％以下が好ましく、５５％以上８０％以下がより好ましく、６５％以上７５％以下が特に好ましい。
　ビーズ充填率が小さ過ぎると、炭素繊維が縦割れし難くなり、アスペクト比の大きなカーボンナノワイヤーができ難い場合等がある。一方、ビーズ充填率が大き過ぎると、ビーズミルの撹拌羽根が回り難くなる場合等がある。 As a bead packing factor used for a bead mill, 45% or more and 85% or less are preferable, 55% or more and 80% or less are more preferable, and 65% or more and 75% or less are particularly preferable.
When the bead filling rate is too small, it is difficult for the carbon fiber to be vertically cracked, and it may be difficult to produce a carbon nanowire with a large aspect ratio. On the other hand, when the bead packing rate is too large, the stirring blade of the bead mill may not be easily rotated.
　上記ビーズミル処理に用いる撹拌羽根の形状は、プロペラ型であることが、分散液が極めて高い構造粘性やチクソトピー性を有するため、ずり速度を大きくし（粘度を大きくさせず）、撹拌性、粉砕性、分散性等を好適に保つために好ましい。 The shape of the stirring blade used in the bead mill processing is a propeller type, and since the dispersion has extremely high structural viscosity and thixotropy, the shear rate is increased (the viscosity is not increased), and the stirring property and the grinding property In order to keep the dispersibility properly.
　撹拌羽根（アジテータ）の回転数は、撹拌羽根の差し渡し長さにも依るが、５００ｒｐｍ以上２０００ｒｐｍ以下が好ましく、７００ｒｐｍ以上１５００ｒｐｍ以下がより好ましく、１０００ｒｐｍ以上１２００ｒｐｍ以下が特に好ましい。
　撹拌羽根（アジテータ）の先端の周速度は、撹拌羽根の差し渡し長さにも依るが、直径２０ｃｍとして、上記回転数から計算できる範囲が好ましい。具体的には、５ｍ／ｓ以上２０ｍ／ｓ以下が好ましく、７ｍ／ｓ以上１６ｍ／ｓ以下がより好ましく、９ｍ／ｓ以上１３ｍ／ｓ以下が特に好ましい。 Although the number of rotations of the stirring blade (agitator) depends on the length of the stirring blade, it is preferably 500 rpm or more and 2000 rpm or less, more preferably 700 rpm or more and 1500 rpm or less, and particularly preferably 1000 rpm or more and 1200 rpm or less.
The peripheral speed of the tip of the agitating blade (agitator) depends on the length of the agitating blade, but is preferably in the range which can be calculated from the above-mentioned rotational speed as a diameter of 20 cm. Specifically, 5 m / s or more and 20 m / s or less are preferable, 7 m / s or more and 16 m / s or less are more preferable, and 9 m / s or more and 13 m / s or less are particularly preferable.
　ビーズミルの粉砕分散の運転方式は、循環式でもバッチ式でもよいが、循環式が好ましい。循環式の場合は、バッチ式のように容器に受け渡しすることがないので、その際に再凝集が進んでしまうことがない。
　循環式で行う場合、パス回数で微細化の程度が変わってくる。例えば、５０００ｍＬで１パス当たりの滞留時間を６０分と長くした場合、処理物のショートパスがないことで、粒度分布はシャープになるが、カーボンナノワイヤー自体のアスペクト比も小さくなってしまう。そのため、例えば、循環速度を１パス当たり、好ましくは１０分～４０分、特に好ましくは１５分以上３０分とし、好ましくは２パス以上、特に好ましくは３パス以上することが望ましい。 The operation mode of the grinding and dispersion of the bead mill may be either a circulation system or a batch system, but the circulation system is preferred. In the case of the circulation type, since it is not delivered to the container as in the batch type, reagglomeration does not proceed at that time.
When the circulation method is used, the degree of miniaturization changes with the number of passes. For example, when the residence time per pass is increased to 60 minutes at 5000 mL, the particle size distribution becomes sharp due to the absence of the short path of the treated product, but the aspect ratio of the carbon nanowire itself also decreases. Therefore, for example, it is desirable that the circulation speed per pass is preferably 10 minutes to 40 minutes, particularly preferably 15 minutes to 30 minutes, preferably 2 passes or more, particularly preferably 3 passes or more.
　１パス当たりの時間（連続運転時間）、パス回数、及び、トータルの時間は、装置構造、濃度、粉砕分散条件、炭素繊維（ＣＦＲＰ）の種類、陰イオン系界面活性剤の種類等に依存する場合があるので、湿式粉砕した後の分散液を、粒子径分布測定装置、走査型電子顕微鏡（ＳＥＭ）等で逐一観察して適宜調節する。本発明のカーボンナノワイヤー分散液の製造方法を使用すれば、平均繊維径３００ｎｍ以下、平均アスペクト比３０以上２００以下のカーボンナノワイヤーが分散された分散液を調製可能である。 The time per pass (continuous operation time), the number of passes, and the total time depend on the device structure, concentration, grinding dispersion conditions, type of carbon fiber (CFRP), type of anionic surfactant, etc. Since there are cases, the dispersion after wet-pulverization is appropriately adjusted by observing one by one with a particle size distribution measuring device, a scanning electron microscope (SEM) or the like. By using the method for producing a carbon nanowire dispersion according to the present invention, it is possible to prepare a dispersion in which carbon nanowires having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 or more and 200 or less are dispersed.
　湿式粉砕・分散の時間は、１パス当たりの時間（連続運転時間）は、７分以上４５分未満が好ましく、１０分以上４０分以下がより好ましく、１５分以上３０分以下が特に好ましい。上限を上記以下にすると、平均アスペクト比を大きくできる。また、湿式粉砕・分散のトータルの時間は、２０分以上１８０分以下が好ましく、６０分以上９０分以下が特に好ましい。 The time per one pass (continuous operation time) is preferably 7 minutes to less than 45 minutes, more preferably 10 minutes to 40 minutes, and particularly preferably 15 minutes to 30 minutes. When the upper limit is set to the above or less, the average aspect ratio can be increased. Moreover, 20 minutes or more and 180 minutes or less are preferable, and, as for the total time of wet grinding and dispersion | distribution, 60 minutes or more and 90 minutes or less are especially preferable.
　ビーズミル処理における分散液と炭素繊維（カーボンナノワイヤー）の温度は、好ましくは０℃以上５０℃以下、特に好ましくは５℃以上３５℃以下である。 The temperature of the dispersion and carbon fibers (carbon nanowires) in bead milling is preferably 0 ° C. or more and 50 ° C. or less, particularly preferably 5 ° C. or more and 35 ° C. or less.
　本発明におけるビーズミルは、湿式ビーズミルであるが、縦型でも横型でもよい。
　また、ビーズミルは、市販の装置も使用できる。市販の装置としては、例えば、アシザワ・ファインテック株式会社製のビーズミル、ウィリー・エ・バッコーフェン（ＷＡＢ）社のダイノーミル、アイメックス株式会社のビーズミル、ネッチ社（米）のビーズミル等が挙げられる。 The bead mill in the present invention is a wet bead mill, but may be vertical or horizontal.
Moreover, a bead mill can also use a commercially available apparatus. As a commercially available apparatus, for example, a bead mill manufactured by Ashizawa Finetech Co., Ltd., a Dino Mill of Willie E. Bachkofen (WAB), a bead mill of Imex Co., Ltd., a bead mill of Netti (US) and the like can be mentioned.
＜＜＜界面活性剤＞＞＞
　湿式粉砕は、陰イオン系界面活性剤の存在下でビーズミル処理をして、粉砕と同時に分散させることが好ましい。
　上記陰イオン系界面活性剤は、高分子陰イオン系界面活性剤（「高分子」にはオリゴマーも含まれる）であることが好ましく、酸基を有する（共）重合物の、アルカリ金属塩、アンモニウム塩、アルキルアンモニウム塩、アルキロールアンモニウム塩等であることがより好ましい。 <<< surfactant >>>
The wet grinding is preferably performed by bead milling in the presence of an anionic surfactant to disperse simultaneously with the grinding.
The anionic surfactant is preferably a polymeric anionic surfactant ("polymer" also includes an oligomer), and an alkali metal salt of a (co) polymer having an acid group, More preferably, they are ammonium salts, alkyl ammonium salts, alkylol ammonium salts and the like.
　更に、上記「酸基を有する（共）重合物」は、（メタ）アクリル酸の（共）重合物、（無水）フタル酸の（共）重合物、ビニルベンゼンスルホン酸の（共）重合物、及び、ナフタレンスルホン酸の（共）縮合物からなる群より選ばれた少なくとも１種以上の（共）重合物であることが特に好ましい。ここで、「（共）」、「（メタ）」、「（無水）」と言う記載は、括弧がある場合もない場合も含むことを示す。共重合物の場合の共重合モノマーとしては、特に限定はないが、（メタ）アクリル酸アルキルエステル、（メタ）アクリル酸ヒドロキシアルキルエステル、スチレン等が挙げられる。
　ナフタレンスルホン酸の（共）縮合物とは、ホルムアルデヒド等のアルデヒドで環を結合したものが挙げられる。共縮合物の場合の共縮合モノマーとしては、フェノール、クレゾール、ナフトール等が挙げられる。 Furthermore, the (co) polymer having an acid group is a (co) polymer of (meth) acrylic acid, a (co) polymer of (anhydride) phthalic acid, and a (co) polymer of vinyl benzene sulfonic acid And at least one (co) polymer selected from the group consisting of (co) condensates of naphthalenesulfonic acid is particularly preferable. Here, the descriptions “(co)”, “(meth)”, and “(anhydrous)” indicate that parentheses may or may not be included. Although there is no limitation in particular as a copolymerization monomer in the case of a copolymer, (meth) acrylic acid alkyl ester, (meth) acrylic acid hydroxyalkyl ester, styrene etc. are mentioned.
The (co) condensed product of naphthalenesulfonic acid includes one having a ring bonded by an aldehyde such as formaldehyde. As a co-condensation monomer in the case of co-condensate, phenol, cresol, naphthol and the like can be mentioned.
　酸基を有する（共）重合物のカウンターカチオンは、アルカリ金属塩、アンモニウム塩、アルキルアンモニウム塩、又は、アルキロールアンモニウム塩であることがより好ましいが、特に好ましくはナトリウム塩又はアルキロールアンモニウム塩である。 The counter cation of the (co) polymer having an acid group is more preferably an alkali metal salt, an ammonium salt, an alkyl ammonium salt or an alkylol ammonium salt, particularly preferably a sodium salt or an alkylol ammonium salt is there.
　上記した陰イオン系界面活性剤は、単独で用いてもよく、複数種類を併用してもよい。 The above-mentioned anionic surfactants may be used alone or in combination of two or more.
　陰イオン系界面活性剤を用いることによって、更には（「より」若しくは「特に」）好ましい陰イオン系界面活性剤を用いることによって、炭素繊維を縦に解く効果を奏し、平均繊維長を短くさせずに平均繊維径を細くすることができ、平均アスペクト比の大きなカーボンナノワイヤー（分散液）を得ることができる。 By using an anionic surfactant, and further by using ("more" or "especially") a preferred anionic surfactant, the carbon fiber can be longitudinally unwound to shorten the average fiber length. Without this, the average fiber diameter can be reduced, and carbon nanowires (dispersion liquid) having a large average aspect ratio can be obtained.
　陰イオン系界面活性剤の使用量は、特に限定はないが、粉砕・分散対象である炭素繊維（カーボンナノワイヤーでも同じ）１００質量部に対して、（陰イオン系界面活性剤を２種以上を併用するときはその合計量として）、好ましくは１０質量部以上２００質量部以下が好ましく、より好ましくは２０質量部以上１５０質量部以下であり、特に好ましくは３０質量部以上１００質量部以下である。
　陰イオン系界面活性剤の使用量が少な過ぎると、炭素繊維を縦に解く効果を奏し難くなり、平均繊維長を短くさせずに平均繊維径を細くすることができ難くなり、平均アスペクト比の大きなカーボンナノワイヤー（分散液）を得難くなる場合がある。
　一方、陰イオン系界面活性剤の使用量が多過ぎると、炭素繊維が縦に解けていく途中で凝集を招く場合がある。その結果、カーボンナノワイヤーが凝集した状態の分散液になるので、対象物に付与した場合、得られたものの導電性に影響がでる場合等がある。 The amount of the anionic surfactant used is not particularly limited, but two or more anionic surfactants may be used with respect to 100 parts by mass of carbon fiber (the same applies to carbon nanowires) to be crushed and dispersed. When used in combination), preferably 10 to 200 parts by weight, more preferably 20 to 150 parts by weight, and particularly preferably 30 to 100 parts by weight is there.
If the amount of the anionic surfactant used is too small, the effect of unraveling the carbon fiber is hardly exhibited, and it becomes difficult to narrow the average fiber diameter without shortening the average fiber length, and the average aspect ratio It may be difficult to obtain large carbon nanowires (dispersion liquid).
On the other hand, when the amount of the anionic surfactant used is too large, the carbon fibers may cause aggregation during melting in the longitudinal direction. As a result, a dispersion liquid in a state in which the carbon nanowires are aggregated is obtained, and thus when applied to an object, the conductivity of the obtained material may be affected.
＜＜＜分散媒＞＞＞
　使用される分散媒や好ましい分散媒は、＜カーボンナノワイヤー分散液＞の＜＜分散媒＞＞の項で前記した通りである。 <<< dispersion medium >>>
The dispersion medium to be used and the preferable dispersion medium are as described above in the section of << dispersion medium >> in <carbon nanowire dispersion liquid>.
＜＜＜ビーズミル処理における炭素繊維の含有割合＞＞＞
　本発明のカーボンナノワイヤー分散液中に分散されているカーボンナノワイヤーの含有割合は、前記した通りであるが、製造法においては、分散媒１００質量部の中に、乾式粉砕した炭素繊維を２質量部以上７質量部以下で含有させて湿式粉砕をすることが好ましい。より好ましくは３質量部以上６．５質量部以下であり、特に好ましくは４質量部以上６質量部以下である。
　含有割合が小さ過ぎると、分散液の粘度が下がり過ぎて、粉砕の効率が低下する場合があり、一方、含有割合が大き過ぎると、分散液の粘度が上がり過ぎて、撹拌翼が回り難くなったり、粉砕の効率が低下したりする場合がある。 <<< Content ratio of carbon fiber in bead mill processing >>>
The content ratio of the carbon nanowires dispersed in the carbon nanowire dispersion liquid of the present invention is as described above, but in the production method, 2 parts by mass of dry pulverized carbon fiber in 100 parts by mass of dispersion medium is used. It is preferable to carry out wet grinding by containing it in an amount of 7 parts by mass or less. More preferably, it is 3 parts by mass or more and 6.5 parts by mass or less, and particularly preferably 4 parts by mass or more and 6 parts by mass or less.
If the content ratio is too small, the viscosity of the dispersion may be too low and the efficiency of pulverization may decrease. On the other hand, if the content ratio is too large, the viscosity of the dispersion may be too high to make the stirring blade difficult to turn And the efficiency of grinding may decrease.
＜＜＜カーボンナノワイヤー分散液＞＞＞
　本発明は、上記の「カーボンナノワイヤー分散液の製造方法」で製造されるようなものであることを特徴とするカーボンナノワイヤー分散液でもある。 <<< Carbon nanowire dispersion liquid >>>
The present invention is also a carbon nanowire dispersion characterized in that it is produced by the above-mentioned "Method of producing a carbon nanowire dispersion".
＜カーボンナノワイヤー分散液の用途＞
　本発明の前記したカーボンナノワイヤー分散液は、塗料やインクのような、構造体若しくは基板の表面に付与する用途に用いることが特に好適である。
　本発明のカーボンナノワイヤー分散液を用いた塗料やインクは、対象物の表面に、導電性、熱伝導性、放熱性、防錆性、漆黒性等を好適に与えることができる。本発明は、対象物の表面に、導電性、熱伝導性、放熱性、防錆性又は漆黒性を与えるための塗料若しくはインクでもある。
　また、本発明のカーボンナノワイヤー分散液や、それに高分子を溶解させ分散媒（溶媒）を留去してなる「該高分子にカーボンナノワイヤーが内包された」「塗膜、回路、構造体若しくは粉末」は、上記性能を持った機能性のものとして好適である。 <Application of Carbon Nanowire Dispersion>
It is particularly preferable to use the above-described carbon nanowire dispersion liquid of the present invention for application to the surface of a structure or a substrate, such as paint or ink.
The paint and the ink using the carbon nanowire dispersion liquid of the present invention can suitably impart conductivity, thermal conductivity, heat dissipation, rust resistance, jet blackness and the like to the surface of an object. The present invention is also a paint or ink for imparting conductivity, heat conductivity, heat dissipation, rust resistance or jet-blackness to the surface of an object.
In addition, the carbon nanowire dispersion liquid of the present invention, and a polymer dissolved therein, and the dispersion medium (solvent) being distilled off, "the carbon nanowire is encapsulated in the polymer", "coating film, circuit, structure Or "powder" is suitable as a functional thing with the said performance.
　該インクの印刷方法としては、特に限定はなく、インクジェット印刷、スクリーン印刷、電子写真印刷、オフセット印刷、凸版印刷、凹版印刷、グラビア印刷、タンポ印刷、手書き印刷等が挙げられる。 The method of printing the ink is not particularly limited, and examples thereof include inkjet printing, screen printing, electrophotographic printing, offset printing, relief printing, intaglio printing, gravure printing, tampo printing, handwriting printing, and the like.
＜＜水系＞＞
　また、本発明は、前記のカーボンナノワイヤー分散液の分散媒が水であり、そこに更に少なくとも水溶性高分子を含有してなるものであることを特徴とする「塗料若しくはインク」でもある。特に好ましくは、上記のカーボンナノワイヤー分散液の分散媒が水であり、そこに更に少なくとも水溶性高分子を含有してなるものであることを特徴とする「導電体形成用水系塗料若しくは水系インク」である。 << Water system >>
The present invention is also a "paint or ink" characterized in that the dispersion medium of the carbon nanowire dispersion described above is water, and further contains at least a water-soluble polymer. Particularly preferably, the dispersion medium of the above-mentioned carbon nanowire dispersion liquid is water, and at least a water-soluble polymer is further contained therein. ".
　上記水溶性高分子としては、水系の塗料やインクに使用されるものが使用できるが、ポリビニルアルコール、ポリビニルピロリドン、高分子量ポリエステル等が、フィルム、紙面、繊維へのコーティングによる密着性が良い、浸透性に影響する硬さを調整できる等の点から好ましい。上記水溶性高分子には、水溶性を維持する範囲で共重合体も含まれる。 As the water-soluble polymer, those used for water-based paints and inks can be used, but polyvinyl alcohol, polyvinyl pyrrolidone, high molecular weight polyester, etc. have good adhesion by coating on film, paper, fiber, etc. It is preferable from the point of being able to adjust the hardness affecting the property. The water-soluble polymer also includes a copolymer as long as the water solubility is maintained.
＜＜有機溶剤系＞＞
　本発明のカーボンナノワイヤー分散液の分散媒は、有機溶媒であってもよい。該有機溶媒としては、前記したものが挙げられる。好ましくは前記したものが挙げられる。特に好ましくは、Ｎ－メチル－２－ピロリドン（ＮＭＰ）、γ－ブチロラクトン（ＧＢＬ）、メチルエチルケトン（ＭＥＫ）等である。 << organic solvent system >>
The dispersion medium of the carbon nanowire dispersion liquid of the present invention may be an organic solvent. Examples of the organic solvent include those described above. Preferably, those mentioned above are mentioned. Particularly preferred are N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (GBL), methyl ethyl ketone (MEK) and the like.
　塗料やインクとするためには、バインダー又はビヒクルとして、高分子を含有させる。
　該高分子としては、特に限定はないが、ポリイミド、ポリエポキシ（前駆体）等が好ましいものとして挙げられる。より好ましくは、芳香族ポリイミド、ポリエポキシ（前駆体）等である。
　該ポリイミドとしてはワニス状態のものを使用できる。また、該ポリエポキシ（前駆体）の場合は、主剤側にでも硬化剤側にでも、該カーボンナノワイヤー分散液を配合することができる。
　芳香族ポリイミドは、通常の高分子に比べて、高強度、高耐熱性を有している。また、線膨張係数は、有機物としては非常に低く金属に近いため、電子回路としたときに、金属（配線）との熱膨張によるひずみが生じ難く、高精度の配線加工が可能であるため、特に芳香族ポリイミドが好ましい。 In order to form a paint or ink, a polymer is contained as a binder or a vehicle.
The polymer is not particularly limited, but polyimide, polyepoxy (precursor) and the like are mentioned as preferable. More preferably, they are aromatic polyimide, polyepoxy (precursor) and the like.
As the polyimide, those in a varnish state can be used. In the case of the polyepoxy (precursor), the carbon nanowire dispersion can be blended on the main agent side or the curing agent side.
Aromatic polyimides have higher strength and higher heat resistance than ordinary polymers. In addition, since the coefficient of linear expansion is very low as an organic substance and close to metal, when forming an electronic circuit, distortion due to thermal expansion with metal (wiring) hardly occurs, and high-precision wiring processing is possible, In particular, aromatic polyimides are preferred.
　本発明は、前記のカーボンナノワイヤー分散液の分散媒が「窒素原子が炭化水素基で置換されていてもよい２－ピロリドン」であり、そこに更に少なくともポリイミドを含有してなるものであることを特徴とする「塗料若しくはインク」でもある。
　また、本発明のカーボンナノワイヤー分散液は、導電性回路形成用インク、導電性塗料等の導電性付与材料に応用されることが特に好ましい。 In the present invention, the dispersion medium of the carbon nanowire dispersion described above is “2-pyrrolidone in which the nitrogen atom may be substituted with a hydrocarbon group”, and further contains at least a polyimide therein. It is also a "paint or ink" characterized by
In addition, the carbon nanowire dispersion liquid of the present invention is particularly preferably applied to a conductivity imparting material such as an ink for forming a conductive circuit, a conductive paint and the like.
＜＜水系と有機溶剤系に共通＞＞
　水系でも有機溶剤系でも、塗料若しくはインクの中には、それらの用途や「塗布方法若しくは印刷方法」に応じて、更に公知の配合剤を含有させることができる。該配合剤としては、例えば、消泡剤、流動性調整剤、有機若しくは無機フィラー、安定化剤、分散（安定）剤、前記以外の界面活性剤、前記分散液の溶媒以外の溶剤、濡れ性改良剤、レベリング剤、可塑剤、構造粘性付与剤、チクソトロピー付与剤等が挙げられる。 << Common to both aqueous and organic solvents >>
In the case of water-based or organic solvent-based, paints or inks may further contain known compounding agents according to their use and "coating method or printing method". As the compounding agent, for example, an antifoamer, a fluidity regulator, an organic or inorganic filler, a stabilizer, a dispersing (stabilizing) agent, a surfactant other than the above, a solvent other than the solvent of the dispersion, wettability Examples include modifiers, leveling agents, plasticizers, structural viscosity imparting agents, thixotropy imparting agents, and the like.
　本発明は、カーボンナノワイヤー分散液であり、該分散液中のカーボンナノワイヤーを含有する「塗料若しくはインク」であると共に、該カーボンナノワイヤーが内包された「塗膜、回路、構造体若しくは粉末」でもある。 The present invention is a carbon nanowire dispersion, which is a "paint or ink" containing carbon nanowires in the dispersion, and a "coating film, circuit, structure or powder in which the carbon nanowire is contained. "
　以下に、実施例及び比較例を挙げて本発明を更に具体的に説明するが、本発明は、その要旨を超えない限りこれらの実施例に限定されるものではない。 EXAMPLES The present invention will be more specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.
測定例１
＜平均繊維径、平均繊維長、平均アスペクト比、粒度分布＞
　本発明における平均繊維径、平均繊維長は、ＳＥＭ（日本電子株式会社製のＪＳＭ７０００番シリーズ）を用いて測定した。平均アスペクト比は、上記方法で求めた平均繊維長を平均繊維径で割って求めた。
　粒度分布は、日機装株式会社製のレーザー回折・散乱式粒子径分布測定装置ナノトラックを用いて湿式で測定し、該測定装置（方法）で測定したものとして定義される。 Measurement example 1
<Average fiber diameter, average fiber length, average aspect ratio, particle size distribution>
The average fiber diameter and the average fiber length in the present invention were measured using SEM (No. JSM 7000 series manufactured by Nippon Denshi Co., Ltd.). The average aspect ratio was determined by dividing the average fiber length determined by the above method by the average fiber diameter.
The particle size distribution is defined as a wet type measurement using a laser diffraction / scattering type particle size distribution measuring apparatus Nanotrac manufactured by Nikkiso Co., Ltd. and measurement using the measuring apparatus (method).
測定例２
＜分散液の粘度＞
　Ｂ型粘度計ＢＭタイプを用い、Ｎｏ．４号ローターを６ｒｐｍで回転させて、そのずり速度での粘度を測定した。温度は２５℃とした。 Measurement example 2
<Viscosity of dispersion>
Using a B-type viscometer BM type, no. The # 4 rotor was rotated at 6 rpm and the viscosity at its shear rate was measured. The temperature was 25 ° C.
測定例３
＜表面処理フィルムの表面抵抗率＞
　ＪｌＳ　Ｌ６９１１に準じて、体積抵抗率（Ω・ｃｍ）を測定した。 Measurement example 3
<Surface Resistivity of Surface Treated Film>
The volume resistivity (Ω · cm) was measured according to JlS L6911.
実施例１
＜原料＞
　原料の「炭素繊維」として、ＣＦＲＰミルドファイバー（長さ７０μｍ～１５０μｍ、直径１１０００ｎｍ）を使用した。この炭素繊維はピッチ系（ＰＩＴＣＨ系）であった。 Example 1
<Raw material>
CFRP milled fiber (70 μm to 150 μm in length, 11000 nm in diameter) was used as “carbon fiber” as a raw material. This carbon fiber was pitch based (PITCH based).
＜乾式粉砕＞
　上記原料５００ｇを、以下の条件で乾式粉砕を行った。乾式粉砕には以下の気流粉砕機であるサイクロンミルを用いた。 <Dry grinding>
Dry grinding was performed on 500 g of the raw material under the following conditions. For dry grinding, a cyclone mill, which is the following air flow grinder, was used.
＜＜装置と乾式粉砕条件＞＞
　使用装置：株式会社静岡プラント製、サイクロンミル１５０Ｓ
　雰囲気温度：室温（２５℃）
　インペラ回転数：８０００ｒｐｍ～１５０００ｒｐｍ
　粉砕時間：１５分 << Apparatus and dry grinding conditions >>
Equipment used: Cyclone mill 150S manufactured by Shizuoka Plant Co., Ltd.
Ambient temperature: room temperature (25 ° C)
Impeller rotational speed: 8000 rpm to 15000 rpm
Grinding time: 15 minutes
＜＜結果＞＞
　その結果、得られたものは、平均繊維径は８０００ｎｍ（９０体積％の分布幅で、５０００ｎｍ～１１０００ｎｍ）、平均繊維長は４５μｍ（９０体積％の分布幅で、２０μｍ～７０μｍ）、平均アスペクト比は５．６であった。 << Result >>
As a result, the obtained product has an average fiber diameter of 8000 nm (a distribution width of 90% by volume, 5000 nm to 11000 nm), an average fiber length of 45 μm (a distribution width of 90% by volume, 20 μm to 70 μm), and an average aspect ratio Was 5.6.
＜予備混合＞
　次に、以下の条件で水と界面活性剤を加えて撹拌する予備混合を行った。 <Premixing>
Next, water and surfactant were added under the following conditions, and pre-mixing was performed to stir.
＜＜処方＞＞
　精製水：１００質量部
　上記で乾式粉砕したもの：５質量部
　陰イオン系界面活性剤：
　　　高縮合ナフタレンスルホン酸ナトリウム：１質量部、及び、
　　　ポリ（メタ）アクリル酸共重合体のアルキロールアンモニウム塩：１質量部 << Prescription >>
Purified water: 100 parts by mass Dry-ground as described above: 5 parts by mass Anionic surfactant:
Highly condensed sodium naphthalene sulfonate: 1 part by mass, and
Alkylol ammonium salt of poly (meth) acrylic acid copolymer: 1 part by mass
＜＜装置と条件＞＞
　撹拌機：新東科学株式会社製、スリーワンモーターＢＬｈ１２００
　撹拌翼：プロペラ型
　回転数：１０００ｒｐｍ～１２００ｒｐｍ
　液温：室温（２５℃）
　撹拌時間：３分～５分 << Devices and conditions >>
Stirrer: Shinto Science Co., Ltd., Three-one motor BLh1200
Stirring blade: Propeller type Rotation speed: 1000rpm-1200rpm
Liquid temperature: room temperature (25 ° C)
Stirring time: 3 to 5 minutes
＜＜結果＞＞
　この予備混合の終了時点で、陰イオン系界面活性剤のために、既に「炭素繊維」が縦に解れて平均繊維径の減少が見られた。
　また、２種の陰イオン系界面活性剤の量を、それぞれ２倍にしたところ、平均繊維径の更なる減少が見られた。平均アスペクト比の増大に関して、陰イオン系界面活性剤、特に高分子（オリゴマーを含む）陰イオン系界面活性剤の効果が確認された。 << Result >>
At the end of this pre-mixing, due to the anionic surfactant, the "carbon fibers" had already been loosened longitudinally and a reduction in average fiber diameter was observed.
In addition, when the amounts of the two anionic surfactants were doubled respectively, a further decrease of the average fiber diameter was observed. The effect of an anionic surfactant, in particular a polymeric (including oligomeric) anionic surfactant, on the increase of the average aspect ratio was confirmed.
＜湿式粉砕と分散処理＞
　次に、上記予備混合で得られた液をそのまま用いて、以下の条件で乾式粉砕を行ってカーボンナノワイヤー分散液を調製した。 <Wet grinding and dispersion treatment>
Next, using the liquid obtained by the above-mentioned preliminary mixing as it was, dry pulverization was performed under the following conditions to prepare a carbon nanowire dispersion liquid.
＜＜装置と湿式粉砕条件＞＞
　使用装置：アシザワ・ファインテック株式会社製の湿式ビーズミル
　方式：循環式
　容器体積：５Ｌ
　使用ビーズ：
　　　ビーズ材質：ジルコニア
　　　ビーズ径：０．５ｍｍ
　　　ビーズ使用量：３５００ｇ（嵩３．５Ｌ）
　ビーズ充填率：７０％
　回転数：アジテータ周速１０ｍ／ｓ
　液温：室温（２５℃）
　ビーズミル処理時間：９０分
　　　１パスの時間：３０分
　　　パスの回数：３回 << equipment and wet grinding conditions >>
Equipment used: Wet bead mill manufactured by Ashizawa Finetech Co., Ltd. Method: Circulation Container volume: 5 L
Use beads:
Bead material: Zirconia Bead diameter: 0.5 mm
Amount of beads used: 3500 g (bulk 3.5 L)
Bead filling rate: 70%
Rotation speed: Agitator circumferential speed 10m / s
Liquid temperature: room temperature (25 ° C)
Bead milling time: 90 minutes 1 pass time: 30 minutes Number of passes: 3 times
＜＜結果＞＞
　上記湿式粉砕により得られたものは、平均繊維径は２００ｎｍ（９０体積％の分布幅で、１００ｎｍ～３００ｎｍ）、平均繊維長は１５μｍ（９０体積％の分布幅で、１０μｍ～２０μｍ）、平均アスペクト比は７５であった。 << Result >>
The above obtained by wet grinding has an average fiber diameter of 200 nm (90 nm by volume distribution, 100 nm to 300 nm), an average fiber length of 15 μm (90 volume% of distribution width, 10 μm to 20 μm), average aspect The ratio was 75.
　実施例１の乾式粉砕後であって湿式粉砕前の炭素繊維の走査型電子顕微鏡写真（ＳＥＭ写真）を図１に示し、湿式粉砕後のカーボンナノワイヤー分散液に分散されているカーボンナノワイヤーの走査型電子顕微鏡写真（ＳＥＭ写真）を図２に示す。 The scanning electron micrograph (SEM photograph) of the carbon fiber after dry-pulverization of Example 1 before wet-pulverization is shown in FIG. 1, and the carbon nanowire dispersed in the carbon nanowire dispersion liquid after wet-pulverization The scanning electron micrograph (SEM photograph) is shown in FIG.
参考例１
　実施例１において、＜乾式粉砕＞と＜予備混合＞は同一とし、＜湿式粉砕と分散処理＞において、ビーズミル処理時間（１パスの時間とパスの回数）を以下のようにした以外は、実施例１と同様に湿式粉砕と分散処理を行った。 Reference Example 1
In Example 1, <dry grinding> and <premixing> are the same, and in <wet grinding and dispersing treatment>, the bead milling time (one pass time and the number of passes) is as follows. Wet pulverization and dispersion treatment were carried out in the same manner as in Example 1.
　ビーズミル処理時間：９０分
　　　１パスの時間：４５分
　　　パスの回数：２回 Bead milling time: 90 minutes 1 pass time: 45 minutes Number of passes: 2 times
＜＜結果＞＞
　上記湿式粉砕により得られたものは、平均繊維径は２００ｎｍ、平均繊維長は０．６７μｍ、平均アスペクト比は３．４であった。粒度分布を図３に示す。 << Result >>
The wet-pulverized product had an average fiber diameter of 200 nm, an average fiber length of 0.67 μm, and an average aspect ratio of 3.4. The particle size distribution is shown in FIG.
実施例２
　実施例１及び参考例１において、＜乾式粉砕＞と＜予備混合＞は同一とし、＜湿式粉砕と分散処理＞において、ビーズミル処理時間（１パスの時間とパスの回数）を以下のようにした以外は、実施例１及び参考例１と同様に湿式粉砕と分散処理を行った。 Example 2
In Example 1 and Reference Example 1, <dry grinding> and <premixing> were the same, and in <wet grinding and dispersing treatment>, bead milling time (one pass time and number of passes) was as follows. The wet grinding and the dispersion treatment were performed in the same manner as in Example 1 and Reference Example 1 except for the above.
　ビーズミル処理時間：３０分
　　　１パスの時間：１５分
　　　パスの回数：２回 Bead milling time: 30 minutes 1 pass time: 15 minutes Number of passes: 2 times
＜＜結果＞＞
　上記湿式粉砕により得られたものは、平均繊維径は２００ｎｍ、平均繊維長は１５μｍ、平均アスペクト比は７５であった。粒度分布を図４に示す。 << Result >>
The wet-pulverized product had an average fiber diameter of 200 nm, an average fiber length of 15 μm, and an average aspect ratio of 75. The particle size distribution is shown in FIG.
　１パスの時間が短い実施例１は、１パスの時間が長い参考例１より、粒度分布はシャープでなくなるが、平均繊維長は長いままを保ち、平均アスペクト比は７５と大きかった。
　一方、１パスの時間が長い参考例１は、粒度分布はシャープになるが、平均繊維長も短くなり、平均アスペクト比は３．４と小さくなった。 In Example 1 in which the time of one pass is short, the particle size distribution was not sharper than in Reference Example 1 in which the time of one pass was long, but the average fiber length remained long and the average aspect ratio was as large as 75.
On the other hand, in Reference Example 1 in which the time of one pass is long, the particle size distribution is sharp, but the average fiber length is short and the average aspect ratio is as small as 3.4.
実施例３
　実施例１で得られた水系のカーボンナノワイヤー分散液５０ｇ（カーボンナノワイヤーを２．５ｇ含有する）、ポリビニルアルコール５０ｇ、及び、ポリメチルメタクリレート（ＰＭＭＡ）（共重合体）２０ｇを撹拌混合し、得られた塗料を汎用のコピー用紙の上に、バーコーターを用いて、１２０ｇ／ｍ２で塗布し乾燥した。 Example 3
50 g of the aqueous carbon nanowire dispersion obtained in Example 1 (containing 2.5 g of carbon nanowire), 50 g of polyvinyl alcohol, and 20 g of polymethyl methacrylate (PMMA) (copolymer) are mixed by stirring, The obtained paint was applied on a general-purpose copy paper at 120 g / m 2 using a bar coater and dried.
　得られた導電性塗膜は、電気抵抗が極めて小さく、しかも塗布面を外側にして１８０°強く折りたたんでも（完全に山折りにしても）、紙の表面は導電性を維持していた。
　平均繊維長が長いために、繊維長が短いナノ粒子よりも繊維長が長いワイヤーが介在する方が相互に接触している部分が多く導電性が途切れなかったと考えられる。また、平均繊維長が長いために、紙の繊維に絡みつくことで粒子の脱落もなく、紙を折り曲げても空隙がカーボンナノワイヤーで接触しているため、複雑に折り曲げても導電性を保持していたと考えられる。 The conductive coating film obtained had an extremely low electrical resistance, and the surface of the paper maintained conductivity even when it was strongly folded 180 ° with the coated surface outward (even if completely folded).
Since the average fiber length is long, it is considered that the conductive property is not interrupted because the portions where wires having long fibers intervene are more in contact with each other than the nanoparticles having short fiber lengths. In addition, since the average fiber length is long, the particles do not fall off by being entangled in the fibers of the paper, and even when the paper is bent, the voids are in contact with the carbon nanowires. It is thought that
実施例４
　実施例１において、＜乾式粉砕＞は同一とし、＜予備混合＞と＜湿式粉砕と分散処理＞を以下のようにした。 Example 4
In Example 1, <dry pulverization> was identical, and <premixing> and <wet pulverization and dispersion treatment> were performed as follows.
＜＜予備混合の処方＞＞
　Ｎ－メチル－２－ピロリドン（ＮＭＰ）：１００質量部
　前記実施例１で乾式粉砕したもの：５質量部
　陰イオン系界面活性剤：
　　　ポリ（メタ）アクリル酸共重合体のアルキロールアンモニウム塩：２質量部 << Premixing recipe >>
N-methyl-2-pyrrolidone (NMP): 100 parts by mass Dry-ground in Example 1 above: 5 parts by mass Anionic surfactant:
Alkylol ammonium salt of poly (meth) acrylic acid copolymer: 2 parts by mass
＜＜装置と条件＞＞
　混合容器：下記の湿式ビーズミル容器内
　撹拌機：防爆用ハンドドリル（２枚の羽根つき）
　回転数：５００ｒｐｍ
　液温：室温（２５℃）
　撹拌条件：下記の湿式ビーズミルの回転を停止し、原料循環戻り容器（ホッパー）に直接上記撹拌機を投入
　撹拌時間：１０秒 << Devices and conditions >>
Mixing container: Wet bead mill container below Stirrer: hand drill for explosion proof (with two blades)
Number of revolutions: 500 rpm
Liquid temperature: room temperature (25 ° C)
Stirring conditions: Stop the rotation of the following wet bead mill, and feed the above agitator directly into the material circulation return vessel (hopper) Stirring time: 10 seconds
＜湿式粉砕と分散処理＞
　次に、上記予備混合で得られた液をそのまま同一容器内で用いて、以下の湿式粉砕を行った。 <Wet grinding and dispersion treatment>
Next, the following wet pulverization was performed using the liquid obtained by the above-mentioned preliminary mixing as it is in the same container.
＜＜装置と湿式粉砕条件＞＞
　使用装置：アシザワ・ファインテック株式会社製の湿式ビーズミル
　方式：循環式
　容器体積：５Ｌ
　使用ビーズ：
　　　ビーズ材質：ジルコニア
　　　ビーズ径：０．５ｍｍ
　　　ビーズ使用量：３５００ｇ（嵩３．５Ｌ）
　ビーズ充填率：７０％
　回転数：アジテータ周速１０ｍ／ｓ
　液温：室温（２５℃）
　ビーズミル処理時間：９０分
　パス回数：３パス
　１パスの時間：３０分 << equipment and wet grinding conditions >>
Equipment used: Wet bead mill manufactured by Ashizawa Finetech Co., Ltd. Method: Circulation Container volume: 5 L
Use beads:
Bead material: Zirconia Bead diameter: 0.5 mm
Amount of beads used: 3500 g (bulk 3.5 L)
Bead filling rate: 70%
Rotation speed: Agitator circumferential speed 10m / s
Liquid temperature: room temperature (25 ° C)
Bead milling time: 90 minutes Number of passes: 3 passes 1 pass time: 30 minutes
＜＜結果＞＞
　上記湿式粉砕により得られたものは、最終的に平均繊維径は２００ｎｍ（９０体積％の分布幅で、１００ｎｍ～３００ｎｍ）、平均繊維長は１０μｍ（９０体積％の分布幅で、５μｍ～１５μｍ）、平均アスペクト比は５０であった。 << Result >>
The average fiber diameter of the product obtained by the above wet pulverization is finally 200 nm (distribution width of 90% by volume, 100 nm to 300 nm), average fiber length is 10 μm (distribution width of 90% by volume, 5 μm to 15 μm) The average aspect ratio was 50.
実施例５
　実施例４において、実施例４と同一の陰イオン系界面活性剤を同量、実施例４の湿式粉砕と分散処理の途中でビーズミル容器内に投入し、実施例４と同様に撹拌した。
　ビーズミル湿式粉砕の過程（時間推移）における、平均繊維径、平均繊維長、粘度の推移は以下の通りであった。ビーズ条件、撹拌条件等は、実施例４と同一とし、時間が推移しても常に条件は固定した。以下は、下に行く程、時間が経過している。「平均」の記載は省略した。 Example 5
In Example 4, the same amount of the anionic surfactant as in Example 4 was introduced into the bead mill container in the middle of the wet pulverization and dispersion treatment of Example 4 and stirred in the same manner as in Example 4.
The transition of the average fiber diameter, the average fiber length, and the viscosity in the bead mill wet grinding process (time transition) was as follows. The bead conditions, the stirring conditions, and the like were the same as in Example 4, and the conditions were always fixed even if time went by. As for the following, as it goes down, time has passed. The description of "average" is omitted.
　ビーズミル湿式粉砕開始
繊維径５０００ｎｍ、繊維長２５μｍ、アスペクト比　５．０、粘度１３００ＭＰａ・ｓ
繊維径１０００ｎｍ、繊維長２０μｍ、アスペクト比２０　　、粘度８０００ＭＰａ・ｓ
　ここで、陰イオン系界面活性剤を添加して、更にケミカル分散開始
繊維径１０００ｎｍ、繊維長１０μｍ、アスペクト比１０　　、粘度　７００ＭＰａ・ｓ
繊維径　２００ｎｍ、繊維長１０μｍ、アスペクト比５０　　、粘度　７００ＭＰａ・ｓ
　ビーズミル湿式粉砕終了 Bead mill wet grinding starting fiber diameter 5000 nm, fiber length 25 μm, aspect ratio 5.0, viscosity 1300 MPa · s
Fiber diameter: 1000 nm, fiber length: 20 μm, aspect ratio: 20, viscosity: 8000 MPa · s
Here, an anionic surfactant is added, and the chemical dispersion start fiber diameter 1000 nm, fiber length 10 μm, aspect ratio 10, viscosity 700 MPa · s
Fiber diameter: 200 nm, fiber length: 10 μm, aspect ratio: 50, viscosity: 700 MPa · s
Finish of bead mill wet grinding
実施例６
　実施例４及び実施例５において、分散媒として、Ｎ－メチル－２－ピロリドン（ＮＭＰ）１００質量部に代えて、γ－ブチロラクトン（ＧＢＬ）１００質量部、又は、メチルエチルケトン（ＭＥＫ）１００質量部を用いた以外は、実施例４及び実施例５と同様に湿式粉砕と分散処理を行った。 Example 6
In Example 4 and Example 5, 100 parts by mass of γ-butyrolactone (GBL) or 100 parts by mass of methyl ethyl ketone (MEK) instead of 100 parts by mass of N-methyl-2-pyrrolidone (NMP) as a dispersion medium The wet pulverization and the dispersion treatment were performed in the same manner as in Example 4 and Example 5 except that they were used.
　ＧＢＬでもＭＥＫでも、ＮＭＰと同様に良好にカーボンナノワイヤー分散液を得ることができた。ただし、ＧＢＬでもＭＥＫでも、湿式粉砕・分散開始後１０分程で凝集性が高まる傾向があったため、分散の進め方や界面活性剤の添加量等のコントロールが、ＮＭＰに比較して難しかった。 Both GBL and MEK were able to obtain a carbon nanowire dispersion as well as NMP. However, in both GBL and MEK, there was a tendency for cohesiveness to increase about 10 minutes after the start of wet pulverization and dispersion, so control of how to proceed dispersion and the amount of surfactant added was more difficult than with NMP.
実施例７
　実施例４で得られたカーボンナノワイヤー分散液を、ポリイミド（ワニスタイプ）に添加した。
　ポリイミドワニスとしては、宇部興産株式会社製、ユピア（登録商標）－ＡＴ（Ｕ－ワニス－Ａ）［一般耐熱用］、及び、ユピア（登録商標）－ＳＴ（Ｕ－ワニス－Ｓ）［高耐熱用］を用いた。 Example 7
The carbon nanowire dispersion obtained in Example 4 was added to a polyimide (varnish type).
As a polyimide varnish, Ube Industries, Ltd. product Yupia (registered trademark) -AT (U-varnish-A) [for general heat resistance], and Yupia (registered trademark)-ST (U-varnish-S) [high heat resistance Was used.
　上記ポリイミドワニス、それぞれ１００質量部に、実施例４で得られたカーボンナノワイヤー分散液を、以下の質量部だけ加えた。
　５質量部（カーボンナノワイヤー０．２５質量部）
１０質量部（カーボンナノワイヤー０．５０質量部）
２０質量部（カーボンナノワイヤー１．０質量部）
４０質量部（カーボンナノワイヤー２．０質量部）
５０質量部（カーボンナノワイヤー２．５質量部）
８０質量部（カーボンナノワイヤー４．０質量部） The carbon nanowire dispersion obtained in Example 4 was added to 100 parts by mass of each of the above-mentioned polyimide varnishes only in the following parts by mass.
5 parts by mass (0.25 parts by mass of carbon nanowires)
10 parts by mass (0.50 parts by mass of carbon nanowires)
20 parts by mass (1.0 parts by mass of carbon nanowires)
40 parts by mass (2.0 parts by mass of carbon nanowires)
50 parts by mass (2.5 parts by mass of carbon nanowires)
80 parts by mass (carbon nanowires 4.0 parts by mass)
　上記を混合する機械として、アズワン株式会社製、オートミキサーＡＳ１００を用い、撹拌時間は１４秒として、それを２回繰り返すことにより、塗料若しくはインクを得た。 A paint or an ink was obtained by using an automatic mixer AS100 manufactured by As One Co., Ltd. as a machine for mixing the above, and repeating this twice with a stirring time of 14 seconds.
　得られた塗料若しくはインクを、２０μｍのポリイミド樹脂フィルムにコーティングを行った。コーターはバーコーターを用い、１２μｍでコーティングをした。
　コーティング後、オーブン中で、１４０℃で５分間、加熱焼成し、表面処理フィルムを得た。 The resulting paint or ink was coated on a 20 μm polyimide resin film. The coater was coated at 12 μm using a bar coater.
After coating, the film was baked by heating at 140 ° C. for 5 minutes in an oven to obtain a surface-treated film.
　ポリイミドワニス１００質量部に、実施例４で得られたカーボンナノワイヤー分散液４０質量部（カーボンナノワイヤー２．０質量部を含有）加えた「塗料若しくはインク」までは、極めて良好な表面処理フィルムが得られた。ただ、５０質量部以上（カーボンナノワイヤー２．５質量部以上）では、表面処理フィルムはできたが、加熱焼成後に樹脂に若干問題が生じた。 Very good surface-treated film up to "paint or ink" added with 40 parts by mass of the carbon nanowire dispersion obtained in Example 4 (containing 2.0 parts by mass of carbon nanowires) to 100 parts by mass of polyimide varnish was gotten. However, in 50 mass parts or more (carbon nanowire 2.5 mass parts or more), although a surface treatment film was made, some problems arose in resin after heating and firing.
＜＜結果＞＞
　上記で得られた塗料若しくはインクを、ポリイミド樹脂フィルムにコーティングを行い、加熱焼成して得られた表面処理フィルムは、何れも、評価方法３で測定した体積抵抗率が１．０×１０－８［Ω・ｃｍ］以下であった。
　上記で得られた塗料若しくはインクは、対象物であるポリイミド樹脂フィルムの表面に、導電性、熱伝導性、放熱性、漆黒性を与えることができた。対象物が金属であれば、防錆性を与えると考えられる。 << Result >>
Each of the surface-treated films obtained by coating the polyimide resin film with the paint or ink obtained above and heating and baking it has a volume resistivity of 1.0 × 10 −8 measured by the evaluation method 3 It was less than [Ω · cm].
The paint or ink obtained above was able to impart conductivity, thermal conductivity, heat dissipation and jet blackness to the surface of the polyimide resin film as the object. If the object is a metal, it is considered to provide corrosion resistance.
　これより、本発明のカーボンナノワイヤー分散液、本発明の塗料若しくはインクを用いることによって、導電性フィルム、熱伝導性フィルム、放熱性フィルム、防錆性フィルム、漆黒性フィルム等が得られた。 From this, by using the carbon nanowire dispersion liquid of the present invention, and the paint or ink of the present invention, a conductive film, a thermally conductive film, a heat dissipating film, an anticorrosive film, a jet-black film and the like were obtained.
実施例８
　実施例７のポリイミドに代えて、エポキシ樹脂、アクリル樹脂を用いて、実施例７と同様にして、塗料若しくはインクを調製し、表面処理フィルムを得た。分散媒としては何れもＮＭＰを用いた。
　何れも、実施例７と同様に、導電性フィルム、熱伝導性フィルム、放熱性フィルム、防錆性フィルム、漆黒性フィルムが得られた。
　硬化剤を含むエポキシ樹脂の場合、硬化して得られたエポキシ樹脂硬化物が、ミクロ相分離構造を形成した。 Example 8
A paint or an ink was prepared in the same manner as in Example 7 using an epoxy resin and an acrylic resin instead of the polyimide of Example 7, to obtain a surface-treated film. As a dispersion medium, NMP was used for all.
In each case, as in Example 7, a conductive film, a heat conductive film, a heat dissipating film, an anticorrosive film, and a jet-black film were obtained.
In the case of the epoxy resin containing a curing agent, the cured epoxy resin cured product formed a micro phase separation structure.
実施例９
　実施例７及び実施例８で得られた「塗料若しくはインク」をガラス瓶の中に入れ、オーブン中、１２０℃で１時間～１時間２０分加熱することで、分散媒を蒸発させ、乾燥体となった粉末を得た。 Example 9
The “paint or ink” obtained in Example 7 and Example 8 is placed in a glass bottle and heated in an oven at 120 ° C. for 1 hour to 1 hour and 20 minutes to evaporate the dispersion medium, and the dried product and Got a powder.
　該粉末は、ナノサイズの粉末であった。何れも凝集したものであったが、水、アクリルモノマー、及び、エポキシ樹脂主剤に容易に拡散させることが可能であった。
　理由として以下が考えられた。すなわち、カーボンナノワイヤーの表面に、湿式粉砕・分散工程において使用した陰イオン界面活性剤（例えば、酸基を含む共重合物のアルキロールアンモニウム塩）が添着しており、乾燥温度１２０℃でも揮発することなく残存しているため、上記分散媒、モノマー、バインダー等に拡散が非常に良かったと考えられる。
　この添着する量は、ビーズミル湿式粉砕・分散の粘度調整時に、添加する陰イオン界面活性剤の量や種類によっても調整し変えることが可能であるので、陰イオン界面活性剤の量や種類によって応用範囲が広がる。 The powder was nano-sized powder. Although all were agglomerated, it was possible to be easily diffused in water, an acrylic monomer, and an epoxy resin main agent.
The following was considered as the reason. That is, the anionic surfactant (for example, an alkylol ammonium salt of a copolymer containing an acid group) used in the wet grinding / dispersion step is attached to the surface of the carbon nanowire, and volatilizes even at a drying temperature of 120 ° C. It is considered that the dispersion is very good in the dispersion medium, the monomer, the binder, etc.
The amount to be attached can be adjusted and changed depending on the amount and type of anionic surfactant added at the time of viscosity adjustment of bead mill wet grinding and dispersion, so application is possible depending on the amount and type of anionic surfactant The range spreads.
　本発明のカーボンナノワイヤー分散液、及び、該分散液を使用した塗料若しくはインクは、特定の形状をしたカーボンナノワイヤーを含有するので、その表面に、導電性、熱伝導性、放熱性、防錆性、漆黒性等を有するようにできる。そのため、該性能を持った「膜、層等」を有する「フィルム、構造体等」や、該性能を持った「粉末、回路、構造体等」が得られるので、該性能を要求されている（要求される）種々の分野に広く利用されるものである。

  The carbon nanowire dispersion liquid of the present invention, and the paint or ink using the dispersion liquid contain carbon nanowires having a specific shape, and therefore, the surface has conductivity, heat conductivity, heat dissipation, prevention It can be made to have rustiness, jet-blackness, etc. Therefore, since "a film, a structure, etc." having "a film, a layer, etc." having the performance, and "powder, a circuit, a structure, etc.", having the performance, such performance is required. It is widely used in various fields (required).

Claims (16)

  1. 　分散媒中に平均繊維径が３００ｎｍ以下であり、かつ、平均アスペクト比が３０以上２００以下のカーボンナノワイヤーが分散されたものであることを特徴とするカーボンナノワイヤー分散液。 A carbon nanowire dispersion liquid characterized in that a carbon nanowire having an average fiber diameter of 300 nm or less and an average aspect ratio of 30 or more and 200 or less is dispersed in a dispersion medium.
  2. 　請求項１に記載のカーボンナノワイヤー分散液の製造方法であって、
    　炭素繊維を乾式粉砕し、又は、乾式粉砕された炭素繊維を用意し、その後、分散媒中で湿式粉砕することによって、該炭素繊維を粉砕しつつ該分散媒に分散させるカーボンナノワイヤー分散液の製造方法であって、
    　該湿式粉砕は、該分散媒の中に、該乾式粉砕した炭素繊維を含有させ、陰イオン系界面活性剤の存在下でビーズミル処理することによって、該炭素繊維を平均繊維径３００ｎｍ以下、かつ平均アスペクト比３０以上２００以下にすることを特徴とするカーボンナノワイヤー分散液の製造方法。     The method for producing a carbon nanowire dispersion liquid according to claim 1,
    A carbon nanowire dispersion liquid in which carbon fibers are dispersed in the dispersion medium by pulverizing the carbon fibers in a dry state or preparing a dry-ground carbon fiber and then grinding the carbon fibers in the dispersion medium by wet grinding. A manufacturing method,
    In the wet grinding, the dry ground carbon fiber is contained in the dispersion medium, and the carbon fiber is subjected to bead milling in the presence of an anionic surfactant, whereby the carbon fiber has an average fiber diameter of 300 nm or less and an average A method for producing a carbon nanowire dispersion liquid, which has an aspect ratio of 30 or more and 200 or less.
  3. 　炭素繊維を平均繊維長７０μｍ以下になるまで乾式粉砕してから上記湿式粉砕をする請求項２に記載のカーボンナノワイヤー分散液の製造方法。 The method for producing a carbon nanowire dispersion liquid according to claim 2, wherein the carbon fibers are dry-grounded to an average fiber length of 70 μm or less and then subjected to the wet-grounding.
  4. 　湿式粉砕前の「上記乾式粉砕した炭素繊維」の平均繊維径が３０００ｎｍ以上であり、かつ平均アスペクト比が１０以下である請求項２又は請求項３に記載のカーボンナノワイヤー分散液の製造方法。 The method for producing a carbon nanowire dispersion liquid according to claim 2 or 3, wherein an average fiber diameter of "the dry ground carbon fiber" before wet grinding is 3000 nm or more and an average aspect ratio is 10 or less.
  5. 　上記分散媒１００質量部の中に、上記乾式粉砕した炭素繊維を２質量部以上７質量部以下で含有させて湿式粉砕をする請求項２ないし請求項４の何れかの請求項に記載のカーボンナノワイヤー分散液の製造方法。 The carbon according to any one of claims 2 to 4, wherein 2 parts by mass or more and 7 parts by mass or less of the dry-pulverized carbon fiber is contained in 100 parts by mass of the dispersion medium and wet-pulverized. Method of manufacturing nanowire dispersion.
  6. 　上記ビーズミル処理におけるビーズ径が０．３ｍｍ以上１ｍｍ以下であり、ビーズ充填率が５５％以上８０％以下である請求項２ないし請求項５の何れかの請求項に記載のカーボンナノワイヤー分散液の製造方法。 The carbon nanowire dispersion liquid according to any one of claims 2 to 5, wherein the bead diameter in the bead milling treatment is 0.3 mm or more and 1 mm or less, and the bead packing ratio is 55% or more and 80% or less. Production method.
  7. 　上記ビーズミル処理に用いる撹拌羽根がプロペラ型であり、該撹拌羽根の回転数が、５００ｒｐｍ以上２０００ｒｐｍ以下である請求項２ないし請求項６の何れかの請求項に記載のカーボンナノワイヤー分散液の製造方法。 The production of the carbon nanowire dispersion liquid according to any one of claims 2 to 6, wherein the stirring blade used for the bead mill treatment is a propeller type, and the rotation speed of the stirring blade is 500 rpm or more and 2000 rpm or less. Method.
  8. 　上記陰イオン系界面活性剤が、酸基を有する（共）重合物の、アルカリ金属塩、アンモニウム塩、アルキルアンモニウム塩又はアルキロールアンモニウム塩である請求項２ないし請求項７の何れかの請求項に記載のカーボンナノワイヤー分散液の製造方法。 The alkali metal salt, ammonium salt, alkyl ammonium salt or alkylol ammonium salt of the (co) polymer having an acid group is an anionic surfactant as described in any one of claims 2 to 7. The manufacturing method of the carbon nanowire dispersion liquid as described in 4.
  9. 　上記酸基を有する（共）重合物が、（メタ）アクリル酸の（共）重合物、（無水）フタル酸の（共）重合物、ビニルベンゼンスルホン酸の（共）重合物、及び、ナフタレンスルホン酸の（共）縮合物からなる群より選ばれた少なくとも１種以上の（共）重合物である請求項８に記載のカーボンナノワイヤー分散液の製造方法。 The (co) polymer having the above acid group is a (co) polymer of (meth) acrylic acid, a (co) polymer of phthalic acid (anhydride), a (co) polymer of vinyl benzene sulfonic acid, and naphthalene The method for producing a carbon nanowire dispersion liquid according to claim 8, which is at least one or more (co) polymers selected from the group consisting of (co) condensates of sulfonic acid.
  10. 　上記炭素繊維が、サイジング処理された炭素繊維又はＣＦＲＰである請求項２ないし請求項９の何れかの請求項に記載のカーボンナノワイヤー分散液の製造方法。 The method for producing a carbon nanowire dispersion liquid according to any one of claims 2 to 9, wherein the carbon fibers are sized carbon fibers or CFRP.
  11. 　上記分散媒が、水、又は、窒素原子が炭化水素基で置換されていてもよい２－ピロリドンである請求項２ないし請求項１０の何れかの請求項に記載のカーボンナノワイヤー分散液の製造方法。 11. The method for producing a carbon nanowire dispersion liquid according to any one of claims 2 to 10, wherein the dispersion medium is water or 2-pyrrolidone in which a nitrogen atom may be substituted with a hydrocarbon group. Method.
  12. 　請求項２ないし請求項１１の何れかの請求項に記載のカーボンナノワイヤー分散液の製造方法で製造されるようなものであることを特徴とするカーボンナノワイヤー分散液。 A carbon nanowire dispersion liquid characterized by being manufactured by the method of manufacturing a carbon nanowire dispersion liquid according to any one of claims 2 to 11.
  13. 　請求項１又は請求項１２に記載のカーボンナノワイヤー分散液の分散媒が水であり、そこに更に少なくとも水溶性高分子を含有してなるものであることを特徴とする塗料若しくはインク。 A paint or ink characterized in that the dispersion medium of the carbon nanowire dispersion liquid according to claim 1 or 12 is water, and at least a water-soluble polymer is further contained therein.
  14. 　請求項１又は請求項１２に記載のカーボンナノワイヤー分散液の分散媒が「窒素原子が炭化水素基で置換されていてもよい２－ピロリドン」であり、そこに更に少なくともポリイミドを含有してなるものであることを特徴とする塗料若しくはインク。 The dispersion medium of the carbon nanowire dispersion liquid according to claim 1 or 12 is “2-pyrrolidone in which a nitrogen atom may be substituted with a hydrocarbon group”, and further contains at least a polyimide therein. Paint or ink characterized in that
  15. 　対象物の表面に、導電性、熱伝導性、放熱性、防錆性又は漆黒性を与えるためのものである請求項１３又は請求項１４に記載の塗料若しくはインク。 The paint or ink according to claim 13 or 14, which is for imparting conductivity, heat conductivity, heat dissipation, rust resistance or jet-blackness to the surface of an object.
  16. 　導電性回路形成用インクである請求項１３ないし請求項１５の何れかの請求項に記載の塗料若しくはインク。 The paint or ink according to any one of claims 13 to 15, which is an ink for forming a conductive circuit.
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