JP7080367B1 - Masterbatch manufacturing method and masterbatch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a masterbatch and a masterbatch capable of producing a masterbatch in which carbon nanotubes are dispersed in a carrier polymer material in a high yield. SOLUTION: A carbon nanotube dispersion liquid in which carbon nanotubes are dispersed in an anionic dispersant or a carbon nanotube dispersion liquid containing carbon nanotubes modified with an oxidation treatment or a polysaccharide and having an acidic group introduced on the surface, and a carrier polymer material. A step of preparing a mixed solution by mixing a carrier polymer material-containing solution containing the above-mentioned carrier polymer material and optionally a cellulose nanofiber dispersion containing cellulose nanofibers, and adding a cationic polymer to the above-mentioned mixed solution to prepare a mixed solution. A method for producing a master batch, which comprises a step of coagulating a solidified product containing carbon nanotubes and a carrier polymer material. [Selection diagram] None

Description

The present invention relates to a masterbatch containing carbon nanotubes and a method for producing the same.

In recent years, research on nanofillers has been advanced. As the nanofiller, carbon nanotubes and the like are known. Carbon nanotubes have excellent properties such as conductivity, thermal conductivity, and mechanical strength, and are attracting attention as materials that are expected to be used in various fields. For example, by blending carbon nanotubes with rubber or the like, it is expected that various performances such as mechanical properties of the product will be improved.

Since carbon nanotubes have high cohesiveness, they are bulky and difficult to handle in a dry state, and it is difficult to uniformly combine them with rubber or the like with a direct kneader. Therefore, it has been studied to support carbon nanotubes on a carrier polymer material to form a masterbatch for use.

Generally, in a master batch, a dispersion containing a filler and a solution containing a carrier polymer material such as rubber are mixed to prepare a mixed solution, and then the mixed solution is coagulated to form a filler and a carrier polymer material. It is manufactured by producing a solidified product containing and.

Further, Patent Document 1 describes a diallylamine-based cationic polymer having a weight average molecular weight of 550,000 to 900,000 (hereinafter referred to as "high molecular weight diallylamine-based cationic polymer") and a weight in the absence of a nonionic surfactant. A diallylamine-based cationic polymer having an average molecular weight of 10,000 to 40,000 (hereinafter referred to as "low molecular weight diallylamine-based cationic polymer") and carbon nanotubes are mixed in the presence of an aqueous solvent to prepare a carbon nanotube suspension. Process and
It has a step of mixing the obtained carbon nanotube suspension and rubber latex.
A carbon nanotube / rubber composite in which the compounding weight ratio of the high molecular weight diallylamine-based cationic polymer and the low molecular weight diallylamine-based cationic polymer is high molecular weight diallylamine-based cationic polymer: low molecular weight diallylamine-based cationic polymer = 100: 10 to 100: 30. The invention relating to the manufacturing method is disclosed.

JP-A-2019-119815

In general, carbon nanotubes have high cohesiveness. Therefore, the carbon nanotubes stabilize the dispersed state of the carbon nanotubes in the liquid in the state before coagulation with the carrier polymer material.

However, due to the stabilization of the dispersed state of the carbon nanotubes in the liquid, solidification with the carrier polymer material may not be completed.

Therefore, an object of the present invention is to provide a method for producing a masterbatch capable of producing a masterbatch in which carbon nanotubes are dispersed in a carrier polymer material in a high yield, and to provide a masterbatch.

According to the study of the present inventor, a carbon nanotube dispersion liquid in which carbon nanotubes are dispersed in an anionic dispersant or a carbon nanotube dispersion liquid containing carbon nanotubes modified with an oxidation treatment or a polysaccharide and having an acidic group introduced on the surface thereof. , A cationic polymer is added to a mixed solution containing a carrier polymer material-containing solution containing the carrier polymer material and optionally a cellulose nanofiber dispersion containing cellulose nanofibers to coagulate the above-mentioned mixed solution. As a result, it has been found that a coagulated product containing carbon nanotubes and a carrier polymer material can be obtained in high yield, and the present invention has been completed. Therefore, the present invention provides the following.

<1> A carbon nanotube dispersion liquid in which carbon nanotubes are dispersed in an anionic dispersant or a carbon nanotube dispersion liquid containing carbon nanotubes modified with an oxidation treatment or a polysaccharide and having an acidic group introduced on the surface, and a carrier polymer material. A step of preparing a mixed solution by mixing a carrier polymer material-containing solution containing the carrier polymer material and optionally a cellulose nanofiber dispersion liquid containing cellulose nanofibers.
A step of adding a cationic polymer to the mixed solution and coagulating the mixed solution to prepare a coagulated product containing carbon nanotubes and a carrier polymer material.
How to make a masterbatch, including.
<2> The cationic polymer comprises at least one selected from a cationic polymer cp1 having a weight average molecular weight of 500 to 10,000 and a cationic polymer cp2 having a weight average molecular weight of 500,000 to 2.5 million. <1 > The method for manufacturing a master batch.
<3> The method for producing a masterbatch according to <1> or <2>, wherein the pH of the carbon nanotube dispersion liquid is 6 to 11 and the pH of the carrier polymer material-containing solution is 6 to 11.
<4> In the step of preparing the mixed solution, the carbon nanotube dispersion, the carrier polymer material-containing solution, and the cellulose nanofiber dispersion are mixed to prepare the mixed solution. <1>- The method for manufacturing a master batch according to any one of <3>.
<5> The master batch according to any one of <1> to <4>, wherein the polysaccharide is at least one selected from carboxymethyl cellulose, carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar and tragant gum. Manufacturing method.
<6> The method for producing a masterbatch according to any one of <1> to <5>, wherein the carrier polymer material contains at least one selected from resin, elastomer and rubber.
<7> The method for producing a masterbatch according to any one of <1> to <6>, wherein the carrier polymer material-containing solution is a latex or an emulsion.
<8> The method for producing a masterbatch according to any one of <1> to <6>, wherein the carrier polymer material-containing solution is a resin particle dispersion liquid containing resin particles.
<9> The method for producing a masterbatch according to <8>, wherein the average particle size of the resin particles is 0.1 to 50 μm.
<10> In the step of coagulating the mixed solution, the acid or salt is added to the mixed solution, and then the cationic polymer is added to the mixed solution, or the cationic polymer is added to the mixed solution. The method for producing a master batch according to any one of <1> to <9>, wherein an acid or a salt is added to the mixed solution.
<11> The method for producing a masterbatch according to any one of <1> to <10>, wherein the cationic polymer contains a polymer having an oxazoline group.
<12> Carbon nanotubes and
Carrier polymer material and
Containing with cationic polymers,
The carbon nanotube is a surface-treated carbon nanotube that has been modified with an oxidation treatment or a polysaccharide and has an acidic group introduced into the surface.
Master Badge.
<13> The cationic polymer comprises at least one selected from a cationic polymer cp1 having a weight average molecular weight of 500 to 10,000 and a cationic polymer cp2 having a weight average molecular weight of 500,000 to 2,500,000. <12 > The master batch described in.
<14> The masterbatch according to <13>, wherein the polysaccharide is at least one selected from carboxymethyl cellulose, carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar and tragant gum.
<15> The masterbatch according to any one of <12> to <14>, wherein the carrier polymer material contains at least one selected from a resin, an elastomer and a rubber.
<16> The masterbatch according to any one of <12> to <15>, wherein the carrier polymer material contains resin particles.
<17> The master batch according to <16>, wherein the resin particles have an average particle diameter of 0.1 to 50 μm.
<18> The master batch according to any one of <12> to <17>, further comprising cellulose nanofibers.
<19> The masterbatch according to any one of <12> to <18>, wherein the cationic polymer contains a polymer having an oxazoline group.

The present invention can provide a method for producing a masterbatch capable of producing a masterbatch in which carbon nanotubes are dispersed in a carrier polymer material in a high yield, and a masterbatch.

In the present specification, the numerical range represented by the symbol "-" means a range including the numerical values before and after "-" as the lower limit value and the upper limit value, respectively.

<Manufacturing method of masterbatch>
The method for producing a masterbatch of the present invention is:
A carbon nanotube dispersion liquid in which carbon nanotubes are dispersed in an anionic dispersant or a carbon nanotube dispersion liquid containing carbon nanotubes modified with an oxidation treatment or a polysaccharide and having an acidic group introduced on the surface, and a carrier height containing a carrier polymer material. A step of preparing a mixed solution by mixing a solution containing a molecular material and optionally a cellulose nanofiber dispersion containing cellulose nanofibers.
A step of adding a cationic polymer to the above-mentioned mixed solution and coagulating the above-mentioned mixed solution to prepare a coagulated product containing carbon nanotubes and a carrier polymer material.
It is characterized by including.

According to the method for producing a master batch of the present invention, it is estimated by adding a cationic polymer to a mixed solution containing the above-mentioned carbon nanotube dispersion liquid and the above-mentioned carrier polymer material-containing solution to coagulate the mixed solution. However, the cationic polymer is ionically bonded to the anionic carbon nanotube by anionic dispersant or oxidation treatment or modification with a polysaccharide, and the carbon nanotube / cationic polymer is entangled by the molecular chain of the carrier polymer material and the cationic polymer. As a result, the coagulation reaction between the carbon nanotube and the carrier polymer material is promoted, and as a result, a coagulated product containing the carbon nanotube and the carrier polymer material can be obtained in good yield. Therefore, according to the method for producing a masterbatch of the present invention, it is possible to produce a masterbatch in which carbon nanotubes are dispersed in a carrier polymer material in a high yield.

Further, according to the method for producing a master batch of the present invention, a carrier polymer material-containing solution in the form of a latex, an emulsion, a resin particle dispersion, or the like is used regardless of the type of the carrier polymer material-containing solution. However, it is possible to produce a master batch in which carbon nanotubes are dispersed in a carrier polymer material in a high yield.

Further, a cationic polymer is added to a mixed solution prepared by mixing the above-mentioned carbon nanotube dispersion liquid, the mixed solution containing the carrier polymer material-containing solution, and the above-mentioned cellulose nanofiber dispersion liquid to coagulate the mixed solution. In this case, a master batch in which carbon nanotubes are dispersed in a carrier polymer material can be produced in a high yield. The detailed reason why such an effect is obtained is unknown, but it is considered to be due to the following reasons. Since cellulose nanofibers often have anionic groups such as carboxy groups, it is presumed that they are easily adsorbed by ionic bonds with cationic polymers. In addition, the glucose unit constituting cellulose has a hydrophilic surface and a hydrophobic surface, and it is presumed that it has a strong interaction with carbon nanotubes in the hydrophobic surface. For the above reasons, it is presumed that the coagulation reaction between the carbon nanotubes and the carrier polymer material can be further promoted via the cellulose nanofibers. Furthermore, the effect of reinforcing the interface between the carbon nanotube and the carrier polymer material can be expected by interposing the cellulose nanofibers between the carbon nanotube and the carrier polymer material.

Hereinafter, each step of the master batch manufacturing method will be described in more detail.

(Mixed solution preparation process)
In the mixed solution preparation step, a carbon nanotube dispersion in which carbon nanotubes are dispersed in an anionic dispersant or a carbon nanotube dispersion containing carbon nanotubes modified with an oxidation treatment or a polysaccharide and having an acidic group introduced on the surface, and a carrier height. A carrier polymer material-containing solution containing a molecular material and a cellulose nanofiber dispersion liquid containing cellulose nanofibers are optionally mixed to prepare a mixed liquid (mixture liquid preparation step).

First, the carbon nanotube dispersion liquid will be described. The carbon nanotube dispersion liquid is a carbon nanotube dispersion liquid in which carbon nanotubes are dispersed in an anionic dispersant (also referred to as the carbon nanotube dispersion liquid of the first aspect), or an acidic group on the surface after being modified with an oxidation treatment or a polysaccharide. A carbon nanotube dispersion liquid containing carbon nanotubes (also referred to as a carbon nanotube dispersion liquid of the second aspect) containing the above-mentioned carbon nanotubes is used. The carbon nanotube dispersion liquid of the second aspect may further contain an anionic dispersant.

Here, the carbon nanotube is a substance in which a graphene sheet is a single-layered or multi-layered tubular substance. The carbon nanotubes in the present specification also include a horn-shaped material called a carbon nanohorn.

The carbon nanotubes used in the carbon nanotube dispersion liquid may be single-walled carbon nanotubes or multi-walled carbon nanotubes. The carbon nanotubes are preferably single-walled to 20-walled carbon nanotubes, and are preferably single-walled to 15-walled carbon nanotubes from the viewpoint of various performances such as mechanical properties, conductivity, heat transfer, and material cost. It is more preferable that there are carbon nanotubes from a single layer to 10 layers. Further, both ends of the carbon nanotube may be open, and one or both of them may be closed.

The average diameter of the carbon nanotubes is preferably 0.03 to 200 nm. When the average diameter of the carbon nanotubes is in the above range, it can have a high aspect ratio, and when it is combined with a resin, rubber, or the like, a high reinforcing effect can be obtained. The lower limit of the average diameter is preferably 1 nm or more, more preferably 3 nm or more, and further preferably 5 nm or more. The upper limit of the average diameter is preferably 150 nm or less, more preferably 100 nm or less, and further preferably 50 nm or less.

The average length of the carbon nanotubes is preferably 0.0005 to 5 mm. If the average length of the carbon nanotubes is in the above range, it can have a high aspect ratio, and when it is combined with a resin, rubber, or the like, a high reinforcing effect can be obtained. The lower limit of the average length is preferably 0.0006 mm or more, more preferably 0.0008 mm or more, and further preferably 0.001 mm or more. The upper limit is preferably 4 mm or less, more preferably 3 mm or less, and further preferably 2 mm or less.

The average aspect ratio of the carbon nanotubes is preferably 100 to 500,000. If the average aspect ratio of the carbon nanotubes is within the above range, it has a high reinforcing effect and is also excellent in handleability. The lower limit of the average aspect ratio is preferably 120 or more, more preferably 150 or more, and even more preferably 200 or more. The upper limit of the average aspect ratio is preferably 450,000 or less, more preferably 400,000 or less, and even more preferably 300,000 or less. In the present specification, the average aspect ratio of carbon nanotubes is the ratio of the average length and the average diameter of carbon nanotubes (average length / average diameter).

In the present specification, the average diameter of carbon nanotubes is obtained by measuring the diameter (outer diameter) of 30 carbon nanotubes randomly selected using a scanning electron microscope or a transmission electron microscope, and determining the average value thereof. It is a calculated value. The average length of the carbon nanotubes is a value calculated by measuring the lengths of 30 carbon nanotubes randomly selected using a scanning electron microscope or a transmission electron microscope and obtaining the average value thereof. ..

The specific surface area of the carbon nanotubes is preferably 100 to 800 m ² / g, more preferably 150 to 700 m ² / g, and even more preferably 200 to 600 m ² / g. In the present specification, the specific surface area of carbon nanotubes is a value at the BET specific surface area measured by a gas adsorption method (multi-point method) based on JIS Z8830 (ISO 9277).

The carbon nanotubes can be produced by known methods such as an arc method, a laser ablation method, and a chemical vapor deposition method (CVD method). Further, it can also be produced by the method described in paragraphs 0029 to 0038 of JP-A-2020-180251.

The carbon nanotubes may be oxidized or modified with a polysaccharide to introduce an acidic group on the surface. Examples of the acidic group include a carboxy group and the like.

The carbon nanotubes that have been oxidized are not particularly limited, and for example, carbon that has been oxidized by a method such as a gas phase oxidation method by heating with air, an oxidation method by electrochemical treatment, or an oxidation method using an oxidizing agent. Examples thereof include nanotubes. Oxidizing agents include ozone; persulfates such as potassium persulfate and sodium persulfate; hypochlorites such as sodium hypochlorite and potassium hypochlorite; persulfates, nitrates, sulfuric acids and hypochlorites. Acids such as, hydrogen peroxide and the like. Ozone as an oxidant can be supplied in the form of gaseous ozone, liquid ozone, or ozone dissolved in an aqueous solvent such as water. The ozone-containing gas can optionally be diluted with a gas such as oxygen, air, nitrogen, a noble gas or a mixture thereof. Conventionally available or commercially available ozone generators can be used to generate ozone or ozone-containing gas. A gas such as air or pure oxygen can be supplied to the ozone generator to generate ozone or ozone-containing gas.

Further, by heating the carbon nanotubes in an oxygen-containing atmosphere, the oxidized carbon nanotubes can be obtained. Further, the carbon nanotubes that have been oxidized can be obtained by mixing the carbon nanotubes with the alkali metal hydroxide and heating in an oxygen-containing atmosphere to remove the alkali metal by washing with water or the like. Further, the carbon nanotubes can be oxidized by plasma treatment, corona discharge treatment, glow discharge treatment, or oxygen bubbling treatment in water.

The acid group content on the oxidized carbon nanotubes is, for example, the Bame method (HP Boehm, E. Diehl, W. Heck and R. Sappoke, "Surface Oxides of Carbon" Angle.Chem.inlernat.Edit. It can be measured by Vol. 3 (1964) No. 10, pp. 669-677). The Bame method is a method in which various alkalis are added to a measurement sample and reacted, and the concentration of the alkali after the reaction is back-titrated with an acid to quantify the amount of acidic functional groups present on the surface of the measurement sample.

The polysaccharide used for surface modification of carbon nanotubes is preferably an acidic polysaccharide. Examples of the acidic polysaccharide include carboxymethyl cellulose, carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar and tragant gum, and carboxymethyl cellulose because it can further improve the dispersibility of carbon nanotubes in the dispersion liquid. Is preferable.

As the anionic dispersant used in the carbon nanotube dispersion liquid, a compound having an anionic group is used. Examples of the anionic group include a carboxy group, a sulfo group, a phospho group, and salts thereof. The hydrogen atom of the carboxy group, the sulfo group and the phospho group may be dissociated. Examples of the atoms or atomic groups constituting the salt include alkali metal ions, alkaline earth metal ions, ammonium ions, onium ions of organic amines, copper ions, silver ions, aluminum ions, metal ions such as tin ions and the like. Specific examples of the anionic dispersant include carboxymethyl cellulose, caraginan, pectin, arabic gum, xanthan gum, gellan gum, agar, tragant gum and salts thereof; anionic modified polyvinyl alcohol; anionic modified polyacrylamide, and the like, and the effects of the present invention are given. The anionic dispersant is preferably carboxymethyl cellulose and salts thereof because it is more prominently available. The weight average molecular weight of the anionic dispersant is preferably 1,000 to 20,000,000. The upper limit of the weight average molecular weight is preferably 15,000,000 or less, and more preferably 10,000,000 or less. The lower limit of the weight average molecular weight is preferably 10,000 or more, more preferably 50,000 or more, and further preferably 100,000 or more.

Examples of the solvent contained in the carbon nanotube dispersion liquid include water, methanol, ethanol, normal propanol, isopropanol, tert-butyl alcohol, tetrahydrofuran, acetone, acetonitrile and the like, and water is preferable. Water has a high relative permittivity, and by using water as a solvent, the dispersibility of carbon nanotubes in the dispersion liquid is also good. Furthermore, when the cationic polymer is added, the dispersibility of the cationic polymer in the liquid is also good.

The carbon nanotube dispersion may further contain a surfactant or a filler (carbon black, graphene, silica, talc, nanoclay, etc.).

The pH of the carbon nanotube dispersion is preferably 6 to 11, and more preferably 7 to 11. When the pH of the carbon nanotube dispersion liquid is in the above range, the dispersibility of the carbon nanotubes is good. In the present specification, the value of pH is a value at 25 ° C.

The solid content concentration of the carbon nanotube dispersion is preferably 0.01 to 15% by mass, more preferably 0.05 to 10% by mass, and even more preferably 0.08 to 8% by mass. When the solid content concentration of the carbon nanotube dispersion liquid is within the above range, a solidified body can be obtained more efficiently. Further, the dispersibility of the carbon nanotubes in the carbon nanotube dispersion liquid is also good. The content of carbon nanotubes in the carbon nanotube dispersion is preferably 0.01 to 10% by mass, more preferably 0.05 to 8% by mass, and 0.1 to 5% by mass. Is even more preferable.

Next, the carrier polymer material-containing solution will be described. The carrier polymer material contained in the carrier polymer material-containing solution is not particularly limited, and examples thereof include resins, elastomers, and rubbers. The resin may be a thermoplastic resin or a thermosetting resin. Examples of the resin include known materials, such as polyester resin, polyether resin, polyolefin resin, polystyrene resin, polyamide resin, polycarbonate resin, acrylic resin, polyvinyl chloride resin, polyphenylene sulfide resin, polyphenylene ether resin, and polytetra. Fluoroethylene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyketone resin, polyetherketone resin, polyetheretherketone resin, polyallylate resin, polyethernitrile resin, phenol resin, Examples thereof include phenoxy resin, fluororesin, urea resin, melamine resin, benzoguanamine resin, alkyd resin, epoxy resin, silicone resin, urethane resin, furan resin, and xylene resin. Examples of the elastomer include known materials, and examples thereof include polystyrene elastomers, polyolefin elastomers, polyurethane elastomers, polyester elastomers, polyamide elastomers, polybutadiene elastomers, polyisoprene elastomers, fluoroelastomers, and silicone elastomers. Examples of the rubber include known materials, such as natural rubber (NR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), nitrile rubber, hydride nitrile rubber, polyisoprene rubber (IR), and butadiene rubber. (BR), butyl rubber (IIR), chloroprene rubber (CR), acrylic rubber (ACM), fluororubber (FKM, PTFE) and the like can be mentioned. The weight average molecular weight of the carrier polymer material is preferably 5,000 to 15,000,000, more preferably 8,000 to 13,000, and 10,000 to 1,000,000. It is more preferable to have. In the present specification, the weight average molecular weight of the carrier polymer material means the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

Examples of the carrier polymer material-containing solution include latex, emulsion, resin particle dispersion and the like. According to the method for producing a masterbatch of the present invention, a masterbatch in which carbon nanotubes are dispersed in a carrier polymer material can be produced in a high yield even when a resin particle dispersion is used as a carrier polymer material-containing solution. Therefore, the effect of the present invention is more remarkably exhibited when the resin particle dispersion liquid is used.

For the latex or emulsion used as the carrier polymer material-containing solution, for example, the reaction solution obtained by synthesizing the carrier polymer material such as resin, elastomer and rubber by the emulsifier polymerization method may be used as it is or diluted appropriately. , Can be prepared by adding an emulsifier. Further, a reaction solution obtained by synthesizing a carrier polymer material such as a resin, an elastomer and a rubber by a solution polymerization method may be phase-inverted to an aqueous system in the presence of an emulsifier to prepare a latex or an emulsion.

The resin particle dispersion liquid used as the carrier polymer material-containing solution can be prepared by dispersing the resin particles in a solvent in the presence of a surfactant or a dispersant.

The average particle size of the resin particles is preferably 0.05 to 50 μm. The lower limit value is preferably 0.07 μm or more, more preferably 0.1 μm or more, further preferably 0.15 μm or more, and particularly preferably 0.2 μm or more. The upper limit is preferably 40 μm or less, more preferably 30 μm or less. When the average particle size of the resin particles is within the above range, it is possible to obtain a material in which the carbon nanotubes are uniformly dispersed on the surface of the resin particles when they are composited by aggregation with the carbon nanotubes. In the present specification, the average particle diameter of the resin particles is the median diameter measured by the laser diffraction / scattering method.

The surfactant is preferably a water-soluble surfactant. Types of surfactants include nonionic surfactants, anionic surfactants and cationic surfactants, but from the viewpoint of reactivity with cationic polymers, nonionic surfactants or anionic surfactants. Is preferable. Examples of the nonionic surfactant include ether-based surfactants such as polyoxyethylene alkyl ether and polyoxyethylene alkyl phenyl ether; and fatty acid ester-based surfactants such as polyoxyethylene oleate and diethyl polyoxyethylene oleate. Agents; Sugar ester-based surfactants such as sorbitan fatty acid ester and polyoxyethylene sorbitan fatty acid ester; Aromatic surfactants such as polyoxyalkylene octylphenyl ether, polyoxyalkylene nonylphenyl ether and polyoxyethylene cumylphenyl ether. Can be mentioned. Examples of commercially available nonionic surfactants include Nonal 912A manufactured by Toho Chemical Industry Co., Ltd. Examples of the anionic surfactant include alkyl sulfates such as sodium lauryl sulfate, triethanolamine lauryl sulfate, and ammonium lauryl sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, and ammonium polyoxyethylene disstyreneized ether sulfate. Examples thereof include alkylbenzene sulfonates such as polyoxyethylene alkyl ether sulfate ester salts, alkylbenzene sulfonic acid, sodium alkylnaphthalene sulfonate, and sodium alkyldiphenyl ether disulfonate. Examples of commercially available anionic surfactants include Perex NB-L manufactured by Kao Corporation.

Examples of the dispersant include the above-mentioned anionic dispersants.

Examples of the solvent contained in the carrier polymer material-containing solution include water, methanol, ethanol, normal propanol, isopropanol, tert-butyl alcohol, tetrahydrofuran, acetone, acetonitrile and the like, and water is preferable. Water has a high relative permittivity, and further, when a cationic polymer is added, the dispersibility of the cationic polymer in the liquid is also good.

The carrier polymer material-containing solution may further contain a surfactant or a filler (carbon black, graphene, silica, talc, nanoclay, etc.).

The pH of the carrier polymer material-containing solution is preferably 6 to 11, and more preferably 7 to 11. When the pH of the carrier polymer material-containing solution is in the above range, the dispersed state of the carbon nanotubes in the mixed solution before the addition of the cationic polymer can be stably maintained when mixed with the carbon nanotube dispersion liquid.

The solid content concentration of the carrier polymer material-containing solution is preferably 0.5 to 70% by mass, more preferably 1 to 65% by mass, and further preferably 2 to 60% by mass. When the solid content concentration of the carrier polymer material-containing solution is in the above range, a solidified body can be obtained more efficiently. The content of the carrier polymer material in the carrier polymer material-containing solution is preferably 0.5 to 60% by mass, and more preferably 1 to 50% by mass.

Next, the cellulose nanofiber dispersion liquid will be described. The cellulose nanofiber dispersion liquid contains cellulose nanofibers. Cellulose nanofibers are fine cellulose fibers obtained by defibrating natural cellulose derived from plants or the like to a nanometer size. Cellulose nanofibers are composed of cellulose microfibrils having a high degree of crystallinity, in which about 40 cellulose molecular chains are aggregated. Since cellulose microfibrils have a high elastic modulus and high tensile strength, it is known that cellulose nanofibers composed of cellulose microfibrils have excellent mechanical properties. In addition, the glucose unit constituting cellulose has a hydrophilic surface and a hydrophobic surface, and the hydrophobic surface can interact with a hydrophobic polymer such as a carbon nanotube.

Cellulose nanofibers can be obtained by repeating mechanical treatment of wood fibers with a grinder or homonizer, and can also be obtained by chemically treating the cellulose fibers in the wood fibers and then mechanically treating them in order to reduce the defibration energy. Can be done. The method of chemical treatment is not particularly limited, but a method of introducing an anionic functional group and defibrating is preferable from the viewpoint of reactivity with the cationic polymer. The method for introducing the anionic functional group is not particularly limited, but for example, 2,2,6,6-tetramethylpiperidin 1-oxyl free radical (TEMPO), which is an N-oxyl compound, is used as a catalyst to introduce the surface of fine fibers of cellulose. There are a method of selectively oxidizing and a method of performing carboxymethylation by reacting cellulose with monochloroacetic acid or sodium monochromoacetate in a high-concentration alkaline aqueous solution.

The average diameter of the cellulose nanofibers is preferably 3 to 100 nm, more preferably 4 to 80 nm. When the average diameter of the cellulose nanofibers is within the above range, it is close to the diameter of the carbon nanotubes, so that it is easy to interact with each other when the carbon nanotube dispersion liquid and the cellulose nanofiber dispersion liquid are mixed.

The average fiber length of the cellulose nanofibers measured by the method described below is preferably 0.0005 to 2.0 mm, more preferably 0.001 to 1.5 mm, and 0.0015 to 1.0 mm. It is more preferable to have. When the average fiber length of the cellulose nanofibers is at least the above lower limit value, it is easy to improve the interfacial strength between the carbon nanotubes and the carrier polymer material. When the average fiber length of the cellulose nanofibers is not more than the above upper limit, the carbon nanotubes and the cellulose nanofibers are likely to interact with each other when the carbon nanotube dispersion liquid and the cellulose nanofiber dispersion liquid are mixed.

In the present specification, the average diameter of the cellulose nanofibers is obtained by measuring the diameter (outer diameter) of 30 randomly selected cellulose nanofibers using a scanning electron microscope or a transmission electron microscope, and averaging them. It is a value calculated by calculating the value. The average fiber length of the cellulose nanofibers was calculated by measuring the lengths of 30 randomly selected cellulose nanofibers using a scanning electron microscope or a transmission electron microscope, and calculating the average value thereof. The value.

Examples of commercially available cellulose nanofibers include the Binfis (registered trademark) series manufactured by Sugino Machine Limited.

Examples of the solvent contained in the cellulose nanofiber dispersion liquid include water, methanol, ethanol, normal propanol, isopropanol, tert-butyl alcohol, tetrahydrofuran, acetone, acetonitrile and the like, and water is preferable.

The pH of the cellulose nanofiber dispersion is preferably 5 to 11, and more preferably 6 to 10. As long as the pH of the cellulose nanofiber dispersion is in the above range, the dispersed state can be maintained even when mixed with the carbon nanotube dispersion or the carrier polymer material-containing solution.

The concentration of cellulose nanofibers in the cellulose nanofiber dispersion is preferably 0.05 to 4% by mass, more preferably 0.1 to 3% by mass, and preferably 0.2 to 2% by mass. More preferred. When the cellulose nanofiber concentration of the cellulose nanofiber dispersion liquid is in the above range, a coagulated product can be obtained more efficiently. Furthermore, the dispersibility of the cellulose nanofibers in the cellulose nanofiber dispersion liquid is also good.

In the mixed liquid preparation step, it is preferable to prepare a mixed liquid by mixing the carbon nanotube dispersion liquid, the carrier polymer material-containing solution, and the cellulose nanofiber dispersion liquid. According to this aspect, a masterbatch in which carbon nanotubes are dispersed in a carrier polymer material can be produced in a higher yield.

The pH of the mixed solution obtained in the mixed solution preparing step is preferably 6 to 11, and more preferably 7 to 11.

The solid content concentration of the mixed solution obtained in the mixed solution preparing step is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass, still more preferably 2 to 8% by mass. .. The ratio of the carbon nanotubes in the mixed solution to the carrier polymer material is preferably 200 to 9900 parts by mass, preferably 250 to 9800 parts by mass, based on 100 parts by mass of the carbon nanotubes. More preferably, it is more preferably 300 to 9700 parts by mass. The ratio of the carbon nanotubes to the cellulose nanofibers in the mixed solution is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the carbon nanotubes, and preferably 10 to 80 parts by mass. It is more preferably 15 to 50 parts by mass.

(Coagulation process)
In the coagulation step, a cationic polymer is added to a mixed solution containing the carbon nanotube dispersion obtained in the mixed solution preparation step, the carrier polymer material-containing solution, and optionally the cellulose nanofiber dispersion, and this mixed solution is added. It is coagulated to prepare a coagulated product containing a carbon nanotube and a carrier polymer material.

Examples of the cationic polymer include polymers having a cationic group. Examples of the cationic group include an amino group, an ammonium group, an imino group and salts thereof. Examples of the atom or atomic group constituting the salt include hydroxide ion, halogen ion, carboxylate ion, sulfonic acid ion, fluorine ion, cyanide ion, silicate ion, borate ion, condensed phosphate ion and the like. .. The amino group given as an example of the cationic group is not limited to -NH ₂ , and also includes a substituted amino group and a cyclic amino group. Examples of the substituted amino group include a monoalkylamino group, a dialkylamino group, a monoarylamino group, a diarylamino group, an alkylarylamino group and the like. Cyclic amino groups include pyrrolidine group, piperazine group, piperazine group, morpholine group, pyrrol group, pyrazole group, imidazole group, pyridine group, pyridazine group, pyrimidine group, pyrazine group, oxazole group, isooxazole group, thiazole group, iso. Examples thereof include a thiazole group, a pyrrolidone group, a piperidone group, a 3-morpholinone group, a morpholindione group and the like.

The cationic polymer may be a block polymer or a random polymer. For example, a polymer having a repeating unit derived from an allylamine such as polyallylamine, a condensation polymer of at least one selected from ammonia and an amine compound and epichlorohydrin, and a Hoffman-modified polyacrylamide obtained by Hoffman-modifying polyacrylamide. Condensation of epichlorohydrin with at least one selected from polymers having repeating units derived from allylamine, ammonia and amine compounds, for example, cation-modified polyvinyl alcohol and the like, because the effect of the present invention can be obtained more remarkably. It is preferably a based polymer.

It is also preferable to use a polymer having an oxazoline group as the cationic polymer. According to this aspect, a masterbatch in which carbon nanotubes and a carrier polymer material are firmly bonded can be produced.

Examples of the polymer having an oxazoline group include a polymer having a repeating unit derived from a 2-oxazoline-based monomer and a repeating unit derived from a nitrogen-containing heterocyclic monomer. The content of the repeating unit derived from the 2-oxazoline-based monomer in the polymer having an oxazoline group is 1 to 90 mol%, and the content of the repeating unit derived from the nitrogen-containing heterocyclic monomer is 10 to 99 mol%. Is preferable.

Examples of 2-oxazoline-based monomers include 2-vinyl-2-oxazoline, 4-methyl-2-vinyl-2-oxazoline, 5-methyl-2-vinyl-2-oxazoline, and 4-ethyl-2-vinyl-2-. Oxazoline, 5-ethyl-2-vinyl-2-oxazoline, 4,4-dimethyl-2-vinyl-2-oxazoline, 4,4-diethyl-2-vinyl-2-oxazoline, 4,5-dimethyl-2- Vinyl-2-oxazoline, 4,5-diethyl-2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 4-methyl-2-isopropenyl-2-oxazoline, 5-methyl-2-isopropenyl -2-Oxazoline, 4-ethyl-2-isopropenyl-2-oxazoline, 5-ethyl-2-isopropenyl-2-oxazoline, 4,4-dimethyl-2-isopropenyl-2-oxazoline, 4,4- Examples thereof include diethyl-2-isopropenyl-2-oxazoline, 4,5-dimethyl-2-isopropenyl-2-oxazoline and 4,5-diethyl-2-isopropenyl-2-oxazoline. Examples of the nitrogen-containing heterocyclic monomer include N-vinylpyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrol, and N. -Vinyl imidazole, N-vinyl oxazole, N- (meth) acryloyl pyrrolidone, N- (meth) acryloyl piperidine, N- (meth) acryloyl pyrrylidine, N- (meth) acryloyl morpholine, N-vinyl morpholine, N-vinyl piperidone, N-vinyl-3-morpholinone, N-vinylcaprolactam, N-vinyl-1,3-oxadin-2-one, N-vinyl-3,5-morpholindione, N-vinylpyrazole, N-vinylisoxazole, N -Vinyl thiazole, N-vinyl isothiazole, N-vinylpyridazine and the like can be mentioned.

Polymers having an oxazoline group may further include a (meth) acrylate having an alkyl group having 1 to 12 carbon atoms, an N-alkyl (meth) acrylamide having an alkyl group having 1 to 12 carbon atoms, and two identical or different carbon atoms having 1 carbon atom. N, N-dialkyl (meth) acrylamides having up to 12 alkyl groups, (meth) acrylates or (meth) acrylamides with aromatic substituents, hydroxyalkyl (C1-12) (meth) acrylates or (meth) acrylamides, It may contain repeating units derived from vinyl-based monomers such as (meth) acrylonitrile and (meth) acrylic acid.

The weight average molecular weight of the cationic polymer is preferably 500 to 2,500,000, more preferably 600 to 2,000,000, and even more preferably 700 to 1,500,000.

Further, as a preferred embodiment of the cationic polymer, at least one selected from the cationic polymer cp1 having a weight average molecular weight of 500 to 10,000 and the cationic polymer cp2 having a weight average molecular weight of 500,000 to 2,500,000 is used. Is preferable. Among them, it is more preferable to use the cationic polymer cp1 because the particle size of the aggregated particles produced by the cationic polymer becomes smaller. It is also preferable to use the cationic polymer cp1 and the cationic polymer cp2 in combination. When the cationic polymer cp1 and the cationic polymer cp2 are used in combination, the effect that the size of the aggregated particle size and the aggregation rate can be easily controlled can be obtained. When the cationic polymer cp1 and the cationic polymer cp2 are used in combination, the ratio thereof is preferably 0.5 to 15 parts by mass, preferably 1 to 10 parts by mass, based on 100 parts by mass of the cationic polymer cp1. Is more preferable.

The weight average molecular weight of the cationic polymer cp1 is preferably 500 to 9,000, more preferably 600 to 8,500, and even more preferably 700 to 8,000.

The weight average molecular weight of the cationic polymer cp2 is preferably 550,000 to 2,500,000, more preferably 600,000 to 2,000,000, and more preferably 700,000 to 1,500,000. Is even more preferable.

In the present specification, the weight average molecular weight of the cationic polymer means the weight average molecular weight in terms of polyethylene glycol measured by gel permeation chromatography (GPC).

Commercially available products of the cationic polymer include PAA series (polyallylamine) marketed by Knitbow Medical Co., Ltd. and Unisense series (for example, Unisense FCA1000L, Unisense FCA1001L, Unisense FCA5000L) marketed by Senka Co., Ltd. An aqueous solution of a copolymer of acrylamide and diallyldimethylammonium chloride); Unisense FPA100L, Unisense FPA101L, Unisense FPA102L, Unisense FPA1000L, Unisense FPA1001L, Unisense FPA1002L (above, aqueous solution of poly (diallyldimethylammonium chloride)); Unisense KHF10P (dicyandiamide- Formalin condensate); Unisense KHP10L, Unisense KHP10P (above, dicyandiamide-diethylenetriamine condensate); Unisense KHE100L, Unisense KHE101L, Unisense KHE102L, Unisense KHE105L, Unisense KHE1000L, Unisense KHE1001L (above, dimethylamine, ammonia and epichloro). Aqueous solution of condensate of unisense KHE104L (aqueous solution of condensate of dimethylamine and epichlorohydrin); Unisense FPV1000L (aqueous solution of poly (trimethylaminoethyl methacrylate)); Unisense ZCA100L (acrylic acid salt) -Acrylamide-diallylamine hydrochloride copolymer aqueous solution), etc.), Diacatch series marketed by Mitsubishi Chemical Co., Ltd., Epocross WS-300 (oxazoline group-containing polymer) marketed by Nippon Catalyst Co., Ltd., etc. Can be mentioned.

The amount of the cationic polymer added is 0.01 to 10% by mass with respect to 100 parts by mass of the solid content in the mixed solution containing the carbon nanotube dispersion, the carrier polymer material-containing solution, and optionally the cellulose nanofiber dispersion. The amount is preferably 0.05 to 8 parts by mass, more preferably 0.1 to 5 parts by mass. When the amount of the cationic polymer added is in the above range, a solidified body can be efficiently obtained.

In the coagulation step, the above-mentioned cationic polymer is added to the above-mentioned mixed solution after adding an acid or a salt to the above-mentioned mixed solution, or the above-mentioned cationic polymer is added to the above-mentioned mixed solution, because a coagulated product can be efficiently obtained. It is preferable to add an acid or a salt to the above-mentioned mixed solution after adding. Above all, it is more preferable to add the cationic polymer to the mixed solution and then add the acid or salt to the mixed solution. By connecting the carbon nanotube and the carrier polymer material with the cationic polymer and then adding an acid or a salt, a coagulated product can be obtained more efficiently.

Examples of the acid include formic acid, sulfuric acid, hydrochloric acid, acetic acid and the like. Examples of the salt include 1 to trivalent metal salts such as calcium salts such as sodium chloride, magnesium chloride, calcium nitrate and calcium chloride. Of these, calcium chloride is preferable.

The pH in the mixed solution in the coagulation step using an acid is preferably 2.8 to 4.8. Further, an emulsifier, a spreading oil component, or the like may be added to the mixed solution in this coagulation step, if necessary. Further, a conductive component such as carbon black may be added.

After the coagulation step, a masterbatch can be obtained by separating the produced lumpy coagulated product, washing it with water, dehydrating it, and drying it at about 80 to 110 ° C. As a drying method, for example, various drying devices such as a single shaft extruder, an oven, a vacuum dryer, and an air dryer can be used. Drying may be carried out under normal pressure, but is preferably carried out under reduced pressure (about 10 to 1000 Pa). The drying time varies depending on the size of the dryer used and the like, but is usually about 30 to 180 minutes under reduced pressure. The drying temperature is usually about 50 to 150 ° C.

<Masterbatch>
Next, the masterbatch of the present invention will be described. The masterbatch of the present invention
With carbon nanotubes
Carrier polymer material and
Containing with cationic polymers,
The carbon nanotube is characterized in that it is a surface-treated carbon nanotube that has been modified with an oxidation treatment or a polysaccharide and has an acidic group introduced into the surface.

Examples of carbon nanotubes, carrier polymer materials, and cationic polymers have been described as materials that can be used in the above-mentioned method for producing a masterbatch.

As the method for oxidizing carbon nanotubes, the treatment method described in the above-mentioned method for producing a masterbatch can be mentioned. Examples of the polysaccharide that modifies the surface of the carbon nanotube include those described in the above-mentioned method for producing a master batch, and at least selected from carboxymethyl cellulose, carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar and tragant gum. It is preferably one kind, and more preferably carboxymethyl cellulose.

The carrier polymer material preferably contains at least one selected from resins, elastomers and rubbers. Further, the carrier polymer material preferably contains resin particles. The average particle size of the resin particles is preferably 0.05 to 50 μm. The lower limit value is preferably 0.07 μm or more, more preferably 0.1 μm or more, further preferably 0.15 μm or more, and particularly preferably 0.2 μm or more. The upper limit is preferably 40 μm or less, more preferably 30 μm or less.

The content of the carbon nanotubes in the masterbatch is preferably 0.05 to 30% by mass, more preferably 0.1 to 25% by mass, and further preferably 0.5 to 20% by mass. preferable.

The masterbatch of the present invention preferably further contains cellulose nanofibers. As for the cellulose nanofibers, those described as the materials that can be used in the above-mentioned method for producing a masterbatch can be mentioned. The content of the cellulose nanofibers in the masterbatch is preferably 0.05 to 10% by mass, more preferably 0.1 to 8% by mass, and preferably 0.5 to 5% by mass. More preferred.

The masterbatch of the present invention can be used by mixing a polymer compound for dilution with other additives, if necessary. The polymer compound for dilution is not particularly limited, and examples thereof include resins, elastomers, and rubbers. The resin may be a thermoplastic resin or a thermosetting resin. Examples of the resin include known materials, such as polyester resin, polyether resin, polyolefin resin, polystyrene resin, polyamide resin, polycarbonate resin, acrylic resin, polyvinyl chloride resin, polyphenylene sulfide resin, polyphenylene ether resin, and polytetra. Fluoroethylene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyketone resin, polyetherketone resin, polyetheretherketone resin, polyallylate resin, polyethernitrile resin, phenol resin, Examples thereof include phenoxy resin, fluororesin, urea resin, melamine resin, benzoguanamine resin, alkyd resin, epoxy resin, silicone resin, urethane resin, furan resin, and xylene resin. Examples of the elastomer include known materials, and examples thereof include polystyrene elastomers, polyolefin elastomers, polyurethane elastomers, polyester elastomers, polyamide elastomers, polybutadiene elastomers, polyisoprene elastomers, fluoroelastomers, and silicone elastomers. Examples of the rubber include known materials, such as natural rubber (NR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), nitrile rubber, hydride nitrile rubber, polyisoprene rubber (IR), and butadiene rubber. (BR), butyl rubber (IIR), chloroprene rubber (CR), acrylic rubber (ACM), fluororubber (FKM, PTFE) and the like can be mentioned. These can be appropriately selected depending on the intended use. Further, the type of the polymer compound for dilution may be the same type of material as the carrier polymer material of the masterbatch, or may be a different type of material.

Various molded products can be manufactured by using a known molding method such as injection molding or extrusion molding using the master batch of the present invention.

Hereinafter, the present invention will be described in more detail with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

<Manufacturing of carbon nanotubes>
(Manufacturing Example 1)
Sputtering was performed on one side of the silicon substrate for 10 seconds targeting aluminum to form a supporting film having a film thickness of 1.6 nm and an average roughness (Ra) of 0.2 nm. Subsequently, sputtering was performed on the supported film for 40 seconds using iron as a target to form a catalyst film having a film thickness of 1.0 nm.

Next, three substrates after the film formation of the catalyst film were prepared, and the three substrates were erected on a quartz pedestal (called a boat) in the reaction vessel of the CVD apparatus. Next, the reaction vessel was closed, and the heater was simultaneously energized while reducing the pressure to 1 Pa to start heating inside the reaction vessel. Next, when the temperature inside the reaction vessel approaches 700 ° C., nitrogen gas is supplied to the reaction vessel, and the pump continues to exhaust the inside of the reaction vessel so that the pressure inside the reaction vessel can be maintained at 90 kPa. I went there.

Next, the inside of the reaction vessel is heated to 750 ° C., both nitrogen gas and hydrogen gas are supplied into the reaction vessel, and the pressure inside the reaction vessel is maintained at 30 kPa, resulting in particle formation of the catalyst film. rice field. After the temperature inside the reaction vessel reaches 750 ° C., nitrogen gas, hydrogen gas and acetylene gas are supplied along the surface of the catalyst film from the upper end to the lower end of the substrate in the reaction vessel while being preheated by the heater. , While maintaining the pressure in the reaction vessel at 30 kPa, the synthesis of carbon nanotubes on the substrate was started. The mass flow controller for each gas was adjusted so that the supply flow rates of nitrogen gas, hydrogen gas and acetylene gas were 100 slm, 100 slm and 10 slm, respectively. The synthesis of carbon nanotubes was continued for about 60 minutes. The mixed gas of the above three types of gas was continuously exhausted to the outside of the device by a pump after synthesizing carbon nanotubes on the substrate.

After the synthesis of the carbon nanotubes was completed, the gas supplied to the reaction vessel was switched to nitrogen gas only, and the temperature was lowered from 750 ° C. to room temperature while maintaining the internal pressure of the reaction vessel at 90 kPa. Next, the reaction vessel was opened and the substrate was taken out. Length 1.7 to 2.1 mm, average length 2.0 mm, average number of layers 6 layers, diameter 7 to 10 nm, average diameter 9 nm, specific surface area 364 m ² / g, G / D ratio 0.9, containing metal impurities A linear carbon nanotube with almost no wave at a rate of 250 ppm was obtained.

The length of the carbon nanotubes was evaluated from an SEM image taken with a scanning electron microscope (manufactured by JEOL Ltd., model: JSM-7800F) as it is on the substrate or after cutting the carbon nanotubes from the substrate. Further, the average length of the carbon nanotubes was obtained by arbitrarily selecting 30 carbon nanotubes from the SEM image and calculating the average value of the lengths of the 30 carbon nanotubes.

The number of layers and the diameter of the carbon nanotubes were evaluated from the TEM image taken by a transmission electron microscope (manufactured by Hitachi High-Tech Co., Ltd., model: HF2200) as the substrate or after cutting the carbon nanotubes from the substrate. The average number of carbon nanotube layers was obtained by selecting an arbitrary 30 fields from a TEM image capable of determining the number of carbon nanotube layers and rounding off the numbers after the decimal point in the average value of the number of 30 carbon nanotube layers. .. Further, the average diameter of the carbon nanotubes was obtained by selecting an arbitrary 30 fields from the TEM image and rounding off the numbers after the decimal point in the average value of the diameters of the 30 carbon nanotubes.

The specific surface area (BET value) of the carbon nanotubes was measured by a gas adsorption method (multi-point method) using a specific surface area measuring device (manufactured by Shimadzu Corporation, model: 3Flex) based on JIS Z8830 (ISO 9277).

The G / D ratio of the carbon nanotubes was determined using a Raman microscope (manufactured by RENISHAW, model: inVia). Specifically, the value obtained by dividing the peak intensity of G-band (1590 cm ^-1 ) of the Raman spectrum measured using a Raman microscope by the peak intensity of D-band (1350 cm ^-1 ) was obtained.

<Measuring method of average particle size of resin particles>
The average particle size of the resin particles in the resin particle dispersion was measured by the laser diffraction / scattering method using a laser diffraction / scattering type particle size distribution measuring device (manufactured by Horiba Seisakusho Co., Ltd., model: LA-960). ..

<Manufacturing of masterbatch>
(Example 1)
10 g of the carbon nanotubes obtained in Production Example 1 was dispersed in 2 liters of ion-exchanged water in which 10 g of carboxymethyl cellulose (trade name: Cellogen WS-C, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was dissolved, and a high-pressure homogenizer (Starburst) was used. A carbon nanotube dispersion (pH 7.5) was obtained by passing it through a mini, model HJP-25001) once. 272.7 g of acrylonitrile butadiene rubber (NBR) latex (trade name Nipol LX531B, manufactured by Nippon Zeon Corporation, solid content concentration 66% by mass, pH 11) was added to this carbon nanotube dispersion to prepare a mixed solution. Next, 46.7 g of a cationic polymer (trade name PAA-08, manufactured by Knitbow Medical Co., Ltd., polyallylamine, weight average molecular weight 8,000, solid content 15% by mass) was added to the above mixed solution and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. The recovery rate of the coagulum was 98.2%. The recovery rate was determined from the total amount of solids of the mixed carbon nanotubes, carboxymethyl cellulose, latex and cationic polymer with respect to the weight of the masterbatch after drying.

(Example 2)
A carbon nanotube dispersion was prepared in the same manner as in Example 1. To this carbon nanotube dispersion, 1410 g of ion-exchanged water was added to 340 g of a cellulose nanofiber dispersion (trade name: Binfis WFo-100, manufactured by Sugino Machine Co., Ltd., average diameter: 30 nm, solid content concentration: 2% by mass). A mixed solution was prepared by adding 272.7 g of a solution and 272.7 g of acrylonitrile butadiene rubber (NBR) latex (trade name Nipol LX531B, manufactured by Nippon Zeon Co., Ltd., solid content concentration 66% by mass, pH 11). Next, 46.7 g of a cationic polymer (trade name PAA-08, manufactured by Knitbow Medical Co., Ltd., polyallylamine, weight average molecular weight 8,000, solid content 15% by mass) was added to the above mixed solution and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was obtained from the total solid content of the masterbatch raw materials with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulum was 100%.

(Example 3)
A carbon nanotube dispersion was prepared in the same manner as in Example 1. A mixed solution was prepared by adding 300 g of natural rubber latex (trade name HA, manufactured by Musashino Chemical Co., Ltd., solid content 60% by mass, pH 10.4) to this carbon nanotube dispersion. Next, 3.5 g of a cationic polymer (trade name: Unisense KHE100L, manufactured by Senka Co., Ltd., dimethylamine-ammonia-epichlorohydrin condensate (weight average molecular weight 823), solid content concentration 60% by mass aqueous solution) was added to the above mixed solution. It was added and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was calculated from the total solid content of the masterbatch raw materials with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulum was 98%.

(Example 4)
A carbon nanotube dispersion was prepared in the same manner as in Example 1. A mixed solution was prepared by adding 439 g of hydrogenated nitrile rubber latex (trade name: Zetpol ZP2230LX, manufactured by Nippon Zeon Corporation, solid content concentration 41%, pH 9.7) to this carbon nanotube dispersion. Next, 3.5 g of a cationic polymer (trade name: Unisense KHE100L, manufactured by Senka Co., Ltd., dimethylamine-ammonia-epichlorohydrin condensate (weight average molecular weight 823) with a solid content concentration of 60% by mass) was added to the above mixture. It was added and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was obtained from the total solid content of the masterbatch raw materials with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulum was 100%.

(Example 5)
A carbon nanotube dispersion was prepared in the same manner as in Example 1. A mixture was prepared by adding 383 g of a fluoroacrylic resin emulsion (trade name: SIFCLEAR F101, manufactured by E-Tech Co., Ltd., solid content concentration: 47% by mass, pH 7.7) to this carbon nanotube dispersion. Next, 3.5 g of a cationic polymer (trade name: Unisense KHE100L, manufactured by Senka Co., Ltd., dimethylamine-ammonia-epichlorohydrin condensate (weight average molecular weight 823), solid content concentration 60% by mass aqueous solution) was added to the above mixed solution. It was added and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was obtained from the total solid content of the masterbatch raw materials with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulum was 100%.

(Example 6)
A carbon nanotube dispersion was prepared in the same manner as in Example 1. A mixture was prepared by adding 375 g of a silicone elastomer emulsion (trade name: DOWNSIL IE-7170, manufactured by Dow Toray Co., Ltd., solid content concentration 48% by mass, pH 10.5) to this carbon nanotube dispersion liquid. Next, 5.2 g of a cationic polymer (trade name: Unisense KHE100L, manufactured by Senka Co., Ltd., dimethylamine-ammonia-epichlorohydrin condensate (weight average molecular weight 823), solid content concentration 60% by mass aqueous solution) was added to the above mixed solution. It was added and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was obtained from the total solid content of the masterbatch raw materials with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulum was 100%.

(Example 7)
A carbon nanotube dispersion was prepared in the same manner as in Example 1. Polytetrafluoroethylene (PTFE) particle dispersion (trade name: Polyflon PTFE D-210C, manufactured by Daikin Industries, Ltd., average particle diameter 0.25 μm, solid content concentration 60% by mass, pH 9.7) is added to this carbon nanotube dispersion. A mixed solution was prepared by adding 300 g. Next, 5.2 g of a cationic polymer (trade name: Unisense KHE100L, manufactured by Senka Co., Ltd., dimethylamine-ammonia-epichlorohydrin condensate (weight average molecular weight 823), solid content concentration 60% by mass aqueous solution) was added to the above mixed solution. It was added and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 100%.

(Example 8)
A carbon nanotube dispersion was prepared in the same manner as in Example 1. To this carbon nanotube dispersion liquid, 720 g of a polypropylene dispersion liquid (trade name: Arrow Base YA-6010, manufactured by Unitika Co., Ltd., emulsion, solid content concentration 25% by mass, pH 9.93) was added to prepare a mixed solution. To this mixed solution, 90 g of a 2% by mass solution of a cationic polymer (trade name: Diacatch CHP295, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight 702,000) was added and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 97%.

(Example 9)
Granule-shaped polyphenylene sulfide (trade name MA520, manufactured by DIC Corporation) was pulverized with a fluidized layer type opposed jet mill (trade name Counter Jet Mill AFG, manufactured by Hosokawa Micron Corporation) to obtain a pulverized product (polyphenylene sulfide particles). .. The average particle size of the obtained polyphenylene sulfide particles was 16.2 μm. To 180 g of the obtained polyphenylene sulfide particles, 1800 g of ion-exchanged water was added, 72 g of a nonionic surfactant (trade name: Nonal 912A, manufactured by Toho Kagaku Kogyo Co., Ltd., solid content concentration: 5% by mass) was added, and the mixture was stirred. Further, 180 g of a 2% by mass solution of carboxymethyl cellulose (trade name: Cellogen WS-C, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added, and the mixture was stirred to prepare a polyphenylene sulfide particle dispersion (pH 6.8). This polyphenylene sulfide particle dispersion was mixed with the carbon nanotube dispersion prepared in the same manner as in Example 1 to prepare a mixed solution. Add 5.2 g of a cationic polymer (trade name: Unisense KHE100L, manufactured by Senka Co., Ltd., dimethylamine-ammonia-epichlorohydrin condensate (weight average molecular weight 823), solid content concentration 60% by mass aqueous solution) to this mixed solution and stir. did. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 100%.

(Example 10)
Pellet-shaped polyetherketone (trade name: 381G, Victorex Japan Co., Ltd.) was pulverized with a fluidized layer type opposed jet mill (Hosokawa Micron, counter jet mill AFG) to obtain pulverized products (polyetherketone particles). .. The average particle size of the obtained polyetherketone particles was 12.3 μm. 1800 g of ion-exchanged water was added to 180 g of the obtained polyether ketone particles, 72 g of a nonionic surfactant (trade name: Nonar 912A, manufactured by Toho Chemical Industry Co., Ltd., solid content concentration: 5% by mass) was added, and the mixture was stirred. .. Further, 180 g of a 2% by mass solution of carboxymethyl cellulose (trade name: Cellogen WS-C, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added, and the mixture was stirred to prepare a polyether ketone particle dispersion (pH 7.4). A mixed solution was prepared by mixing a polyether ketone particle dispersion and a carbon nanotube dispersion prepared in the same manner as in Example 1. To this mixed solution, 5.2 g of a cationic polymer (trade name: Unisense KHE100L, manufactured by Senka Co., Ltd., dimethylamine-ammonia-epichlorohydrin condensate (weight average molecular weight 823), solid content concentration 60% by mass aqueous solution) was added. Stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 98%.

(Example 11)
10 g of the carbon nanotubes obtained in Production Example 1 was dispersed in 1990 ml of a 6 mass% hypochlorous acid solution and treated at 50 ° C. for 1 hour. Then, the treated solution was filtered and washed with water until the pH became neutral to obtain an oxidized carbon nanotube (hereinafter referred to as carbon nanotube OT). The carboxy group content of the carbon nanotube OT was 0.1 meq / g. The carboxy group content of the carbon nanotube OT was quantified by the Böhm method. Specifically, 10 ml of 0.1N sodium hydrogen carbonate was added to 30 mg of carbon nanotube OT, ultrasonic treatment was performed for 2 hours, and the mixture was allowed to stand for 3 days. After that, the treatment liquid was filtered, and the filtrate was titrated with 0.01N hydrochloric acid. The neutralization point was determined by an automatic titrator (COM-1750, manufactured by Hiranuma Sangyo Co., Ltd.).

Next, the carbon nanotube OT cake obtained by filtering the above treatment liquid was diluted with ion-exchanged water to 2 liters, and then passed once through a high-pressure homogenizer (Starburst Mini, model HJP-25001). A carbon nanotube dispersion liquid (pH 6.8) was obtained. To this carbon nanotube dispersion liquid, 272.7 g of acrylonitrile butadiene rubber (NBR) latex (trade name Nipol LX531B, manufactured by Nippon Zeon Corporation, solid content concentration 66% by mass, pH 11) is added and mixed in the same manner as in Example 1. The liquid was prepared. Next, 4.7 g of a cationic polymer (trade name PAA-08, manufactured by Knitbow Medical Co., Ltd., polyallylamine, weight average molecular weight 8,000, solid content 15% by mass) was added to the above mixed solution and stirred. Further, a 20% formic acid solution was added until the above mixed solution solidified. The obtained coagulated product was filtered through a mesh having an opening of 149 μm, and the coagulated product was collected. After dehydrating the coagulum, it was dried at 110 ° C. to prepare a masterbatch. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 96.5%.

(Example 12)
A masterbatch was prepared in the same manner as in Example 1 except that 5 g of a 20% calcium chloride solution was added instead of the 20% formic acid solution. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 98.7%.

(Example 13)
Example 1 except that 10.2 g of a cationic polymer (trade name: Epocross WS-300, manufactured by Nippon Shokubai Co., Ltd., oxazoline group-containing polymer, weight average molecular weight: 120,000, solid content: 10% by mass) was added in Example 1. A masterbatch was prepared in the same manner as above. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 95.4%.

(Comparative Example 1)
In Example 1, the same operation as in Example 1 was carried out except that the cationic polymer was not added, to prepare a masterbatch. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 63%. It is probable that the coagulation efficiency was poor because there was no bridge between the carbon nanotubes and the latex due to the cationic polymer.

(Comparative Example 2)
In Example 10, the same operation as in Example 10 was carried out except that the cationic polymer was not added, to prepare a masterbatch. When the recovery rate was calculated from the total weight of the masterbatch raw material solids with respect to the weight of the masterbatch after drying in the same manner as in Example 1, the recovery rate of the coagulated product was 72%. It is probable that this is because the coagulation efficiency was poor because there was no bridge between the carbon nanotubes and the powdered fine particles by the cationic polymer as in Comparative Example 1.

Claims (15)

A carbon nanotube dispersion liquid in which carbon nanotubes are dispersed in an anionic dispersant or a carbon nanotube dispersion liquid containing carbon nanotubes modified with an oxidation treatment or a polysaccharide and having an acidic group introduced on the surface, and a carrier height containing a carrier polymer material. A step of preparing a mixed solution by mixing a solution containing a molecular material and optionally a cellulose nanofiber dispersion containing cellulose nanofibers.
A step of adding a cationic polymer to the mixed solution and coagulating the mixed solution to prepare a coagulated product containing carbon nanotubes and a carrier polymer material.
How to make a masterbatch, including. The first aspect of the present invention, wherein the cationic polymer comprises at least one selected from a cationic polymer cp1 having a weight average molecular weight of 500 to 10,000 and a cationic polymer cp2 having a weight average molecular weight of 500,000 to 2.5 million. How to make a master batch. The method for producing a masterbatch according to claim 1 or 2, wherein the pH of the carbon nanotube dispersion liquid is 6 to 11 and the pH of the carrier polymer material-containing solution is 6 to 11. In any of claims 1 to 3, in the step of preparing the mixed liquid, the carbon nanotube dispersion liquid, the carrier polymer material-containing solution, and the cellulose nanofiber dispersion liquid are mixed to prepare the mixed liquid. The method for manufacturing a master batch according to item 1. The method for producing a master batch according to any one of claims 1 to 4, wherein the polysaccharide is at least one selected from carboxymethyl cellulose, carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar and tragant gum. The method for producing a masterbatch according to any one of claims 1 to 5, wherein the carrier polymer material contains at least one selected from resin, elastomer and rubber. The method for producing a masterbatch according to any one of claims 1 to 6, wherein the carrier polymer material-containing solution is a latex or an emulsion. The method for producing a masterbatch according to any one of claims 1 to 6, wherein the carrier polymer material-containing solution is a resin particle dispersion containing resin particles. The method for producing a masterbatch according to claim 8, wherein the resin particles have an average particle size of 0.1 to 50 μm. In the step of coagulating the mixed solution, the acid or salt is added to the mixed solution, and then the cationic polymer is added to the mixed solution, or the cationic polymer is added to the mixed solution, and then the mixed solution is added. The method for producing a master batch according to any one of claims 1 to 9, wherein an acid or a salt is added to the mixture. The method for producing a masterbatch according to any one of claims 1 to 10, wherein the cationic polymer contains a polymer having an oxazoline group. With carbon nanotubes
Carrier polymer material and
A master batch containing a cationic polymer,
The carbon nanotube is a surface-treated carbon nanotube that has been modified with an oxidation treatment or a polysaccharide and has an acidic group introduced into the surface.
In the master batch, the cationic polymer is ion-bonded to the surface-treated carbon nanotube, and the surface-treated carbon nanotubes bonded to the cationic polymer by the ion bond are entangled with the carrier polymer material and the molecular chain of the cationic polymer. A coagulated product containing the surface-treated carbon nanotube and the carrier polymer material is formed, and the carbon nanotube is dispersed in the coagulated product.
Master Badge. 12. The cation polymer comprises at least one selected from a cation polymer cp1 having a weight average molecular weight of 500 to 10,000 and a cation polymer cp2 having a weight average molecular weight of 500,000 to 2,500,000. Masterbatch. 13. The masterbatch according to claim 13, wherein the polysaccharide is at least one selected from carboxymethyl cellulose, carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar and tragant gum. The masterbatch according to any one of claims 12 to 14, wherein the carrier polymer material contains at least one selected from a resin, an elastomer and a rubber.